swifter/Sources/CSQLite/include/sqlite.h

/*
 ** 2001 September 15
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
 ** This header file defines the interface that the SQLite library
 ** presents to client programs.  If a C-function, structure, datatype,
 ** or constant definition does not appear in this file, then it is
 ** not a published API of SQLite, is subject to change without
 ** notice, and should not be referenced by programs that use SQLite.
 **
 ** Some of the definitions that are in this file are marked as
 ** "experimental".  Experimental interfaces are normally new
 ** features recently added to SQLite.  We do not anticipate changes
 ** to experimental interfaces but reserve the right to make minor changes
 ** if experience from use "in the wild" suggest such changes are prudent.
 **
 ** The official C-language API documentation for SQLite is derived
 ** from comments in this file.  This file is the authoritative source
 ** on how SQLite interfaces are supposed to operate.
 **
 ** The name of this file under configuration management is "sqlite.h.in".
 ** The makefile makes some minor changes to this file (such as inserting
 ** the version number) and changes its name to "sqlite3.h" as
 ** part of the build process.
 */

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wambiguous-macro"
#pragma clang diagnostic ignored "-Wconversion"
#pragma clang diagnostic ignored "-Wunreachable-code"

#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
 ** Make sure we can call this stuff from C++.
 */
#ifdef __cplusplus
extern "C" {
#endif
    
    
    /*
     ** Provide the ability to override linkage features of the interface.
     */
#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif
#ifndef SQLITE_API
# define SQLITE_API
#endif
#ifndef SQLITE_CDECL
# define SQLITE_CDECL
#endif
#ifndef SQLITE_STDCALL
# define SQLITE_STDCALL
#endif
    
    /*
     ** These no-op macros are used in front of interfaces to mark those
     ** interfaces as either deprecated or experimental.  New applications
     ** should not use deprecated interfaces - they are supported for backwards
     ** compatibility only.  Application writers should be aware that
     ** experimental interfaces are subject to change in point releases.
     **
     ** These macros used to resolve to various kinds of compiler magic that
     ** would generate warning messages when they were used.  But that
     ** compiler magic ended up generating such a flurry of bug reports
     ** that we have taken it all out and gone back to using simple
     ** noop macros.
     */
#define SQLITE_DEPRECATED
#define SQLITE_EXPERIMENTAL
    
    /*
     ** Ensure these symbols were not defined by some previous header file.
     */
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif
#ifdef SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif
    
    /*
     ** CAPI3REF: Compile-Time Library Version Numbers
     **
     ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
     ** evaluates to a string literal that is the SQLite version in the
     ** format "X.Y.Z" where X is the major version number (always 3 for
     ** SQLite3) and Y is the minor version number and Z is the release number.)^
     ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
     ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
     ** numbers used in [SQLITE_VERSION].)^
     ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
     ** be larger than the release from which it is derived.  Either Y will
     ** be held constant and Z will be incremented or else Y will be incremented
     ** and Z will be reset to zero.
     **
     ** Since version 3.6.18, SQLite source code has been stored in the
     ** <a href="http://www.fossil-scm.org/">Fossil configuration management
     ** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
     ** a string which identifies a particular check-in of SQLite
     ** within its configuration management system.  ^The SQLITE_SOURCE_ID
     ** string contains the date and time of the check-in (UTC) and an SHA1
     ** hash of the entire source tree.
     **
     ** See also: [sqlite3_libversion()],
     ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
     ** [sqlite_version()] and [sqlite_source_id()].
     */
#define SQLITE_VERSION        "3.11.0"
#define SQLITE_VERSION_NUMBER 3011000
#define SQLITE_SOURCE_ID      "2016-02-15 17:29:24 3d862f207e3adc00f78066799ac5a8c282430a5f"
    
    /*
     ** CAPI3REF: Run-Time Library Version Numbers
     ** KEYWORDS: sqlite3_version, sqlite3_sourceid
     **
     ** These interfaces provide the same information as the [SQLITE_VERSION],
     ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
     ** but are associated with the library instead of the header file.  ^(Cautious
     ** programmers might include assert() statements in their application to
     ** verify that values returned by these interfaces match the macros in
     ** the header, and thus ensure that the application is
     ** compiled with matching library and header files.
     **
     ** <blockquote><pre>
     ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
     ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
     ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
     ** </pre></blockquote>)^
     **
     ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
     ** macro.  ^The sqlite3_libversion() function returns a pointer to the
     ** to the sqlite3_version[] string constant.  The sqlite3_libversion()
     ** function is provided for use in DLLs since DLL users usually do not have
     ** direct access to string constants within the DLL.  ^The
     ** sqlite3_libversion_number() function returns an integer equal to
     ** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns
     ** a pointer to a string constant whose value is the same as the
     ** [SQLITE_SOURCE_ID] C preprocessor macro.
     **
     ** See also: [sqlite_version()] and [sqlite_source_id()].
     */
    SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
    SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void);
    SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void);
    SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void);
    
    /*
     ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
     **
     ** ^The sqlite3_compileoption_used() function returns 0 or 1
     ** indicating whether the specified option was defined at
     ** compile time.  ^The SQLITE_ prefix may be omitted from the
     ** option name passed to sqlite3_compileoption_used().
     **
     ** ^The sqlite3_compileoption_get() function allows iterating
     ** over the list of options that were defined at compile time by
     ** returning the N-th compile time option string.  ^If N is out of range,
     ** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
     ** prefix is omitted from any strings returned by
     ** sqlite3_compileoption_get().
     **
     ** ^Support for the diagnostic functions sqlite3_compileoption_used()
     ** and sqlite3_compileoption_get() may be omitted by specifying the
     ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
     **
     ** See also: SQL functions [sqlite_compileoption_used()] and
     ** [sqlite_compileoption_get()] and the [compile_options pragma].
     */
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
    SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName);
    SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N);
#endif
    
    /*
     ** CAPI3REF: Test To See If The Library Is Threadsafe
     **
     ** ^The sqlite3_threadsafe() function returns zero if and only if
     ** SQLite was compiled with mutexing code omitted due to the
     ** [SQLITE_THREADSAFE] compile-time option being set to 0.
     **
     ** SQLite can be compiled with or without mutexes.  When
     ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
     ** are enabled and SQLite is threadsafe.  When the
     ** [SQLITE_THREADSAFE] macro is 0,
     ** the mutexes are omitted.  Without the mutexes, it is not safe
     ** to use SQLite concurrently from more than one thread.
     **
     ** Enabling mutexes incurs a measurable performance penalty.
     ** So if speed is of utmost importance, it makes sense to disable
     ** the mutexes.  But for maximum safety, mutexes should be enabled.
     ** ^The default behavior is for mutexes to be enabled.
     **
     ** This interface can be used by an application to make sure that the
     ** version of SQLite that it is linking against was compiled with
     ** the desired setting of the [SQLITE_THREADSAFE] macro.
     **
     ** This interface only reports on the compile-time mutex setting
     ** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
     ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
     ** can be fully or partially disabled using a call to [sqlite3_config()]
     ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
     ** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the
     ** sqlite3_threadsafe() function shows only the compile-time setting of
     ** thread safety, not any run-time changes to that setting made by
     ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
     ** is unchanged by calls to sqlite3_config().)^
     **
     ** See the [threading mode] documentation for additional information.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void);
    
    /*
     ** CAPI3REF: Database Connection Handle
     ** KEYWORDS: {database connection} {database connections}
     **
     ** Each open SQLite database is represented by a pointer to an instance of
     ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
     ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
     ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
     ** and [sqlite3_close_v2()] are its destructors.  There are many other
     ** interfaces (such as
     ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
     ** [sqlite3_busy_timeout()] to name but three) that are methods on an
     ** sqlite3 object.
     */
    typedef struct sqlite3 sqlite3;
    
    /*
     ** CAPI3REF: 64-Bit Integer Types
     ** KEYWORDS: sqlite_int64 sqlite_uint64
     **
     ** Because there is no cross-platform way to specify 64-bit integer types
     ** SQLite includes typedefs for 64-bit signed and unsigned integers.
     **
     ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
     ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
     ** compatibility only.
     **
     ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
     ** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
     ** sqlite3_uint64 and sqlite_uint64 types can store integer values
     ** between 0 and +18446744073709551615 inclusive.
     */
#ifdef SQLITE_INT64_TYPE
    typedef SQLITE_INT64_TYPE sqlite_int64;
    typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
#elif defined(_MSC_VER) || defined(__BORLANDC__)
    typedef __int64 sqlite_int64;
    typedef unsigned __int64 sqlite_uint64;
#else
    typedef long long int sqlite_int64;
    typedef unsigned long long int sqlite_uint64;
#endif
    typedef sqlite_int64 sqlite3_int64;
    typedef sqlite_uint64 sqlite3_uint64;
    
    /*
     ** If compiling for a processor that lacks floating point support,
     ** substitute integer for floating-point.
     */
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite3_int64
#endif
    
    /*
     ** CAPI3REF: Closing A Database Connection
     ** DESTRUCTOR: sqlite3
     **
     ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
     ** for the [sqlite3] object.
     ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
     ** the [sqlite3] object is successfully destroyed and all associated
     ** resources are deallocated.
     **
     ** ^If the database connection is associated with unfinalized prepared
     ** statements or unfinished sqlite3_backup objects then sqlite3_close()
     ** will leave the database connection open and return [SQLITE_BUSY].
     ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
     ** and/or unfinished sqlite3_backups, then the database connection becomes
     ** an unusable "zombie" which will automatically be deallocated when the
     ** last prepared statement is finalized or the last sqlite3_backup is
     ** finished.  The sqlite3_close_v2() interface is intended for use with
     ** host languages that are garbage collected, and where the order in which
     ** destructors are called is arbitrary.
     **
     ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
     ** [sqlite3_blob_close | close] all [BLOB handles], and
     ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
     ** with the [sqlite3] object prior to attempting to close the object.  ^If
     ** sqlite3_close_v2() is called on a [database connection] that still has
     ** outstanding [prepared statements], [BLOB handles], and/or
     ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
     ** of resources is deferred until all [prepared statements], [BLOB handles],
     ** and [sqlite3_backup] objects are also destroyed.
     **
     ** ^If an [sqlite3] object is destroyed while a transaction is open,
     ** the transaction is automatically rolled back.
     **
     ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
     ** must be either a NULL
     ** pointer or an [sqlite3] object pointer obtained
     ** from [sqlite3_open()], [sqlite3_open16()], or
     ** [sqlite3_open_v2()], and not previously closed.
     ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
     ** argument is a harmless no-op.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*);
    SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*);
    
    /*
     ** The type for a callback function.
     ** This is legacy and deprecated.  It is included for historical
     ** compatibility and is not documented.
     */
    typedef int (*sqlite3_callback)(void*,int,char**, char**);
    
    /*
     ** CAPI3REF: One-Step Query Execution Interface
     ** METHOD: sqlite3
     **
     ** The sqlite3_exec() interface is a convenience wrapper around
     ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
     ** that allows an application to run multiple statements of SQL
     ** without having to use a lot of C code.
     **
     ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
     ** semicolon-separate SQL statements passed into its 2nd argument,
     ** in the context of the [database connection] passed in as its 1st
     ** argument.  ^If the callback function of the 3rd argument to
     ** sqlite3_exec() is not NULL, then it is invoked for each result row
     ** coming out of the evaluated SQL statements.  ^The 4th argument to
     ** sqlite3_exec() is relayed through to the 1st argument of each
     ** callback invocation.  ^If the callback pointer to sqlite3_exec()
     ** is NULL, then no callback is ever invoked and result rows are
     ** ignored.
     **
     ** ^If an error occurs while evaluating the SQL statements passed into
     ** sqlite3_exec(), then execution of the current statement stops and
     ** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
     ** is not NULL then any error message is written into memory obtained
     ** from [sqlite3_malloc()] and passed back through the 5th parameter.
     ** To avoid memory leaks, the application should invoke [sqlite3_free()]
     ** on error message strings returned through the 5th parameter of
     ** sqlite3_exec() after the error message string is no longer needed.
     ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
     ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
     ** NULL before returning.
     **
     ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
     ** routine returns SQLITE_ABORT without invoking the callback again and
     ** without running any subsequent SQL statements.
     **
     ** ^The 2nd argument to the sqlite3_exec() callback function is the
     ** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
     ** callback is an array of pointers to strings obtained as if from
     ** [sqlite3_column_text()], one for each column.  ^If an element of a
     ** result row is NULL then the corresponding string pointer for the
     ** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
     ** sqlite3_exec() callback is an array of pointers to strings where each
     ** entry represents the name of corresponding result column as obtained
     ** from [sqlite3_column_name()].
     **
     ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
     ** to an empty string, or a pointer that contains only whitespace and/or
     ** SQL comments, then no SQL statements are evaluated and the database
     ** is not changed.
     **
     ** Restrictions:
     **
     ** <ul>
     ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
     **      is a valid and open [database connection].
     ** <li> The application must not close the [database connection] specified by
     **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
     ** <li> The application must not modify the SQL statement text passed into
     **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
     ** </ul>
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_exec(
                                               sqlite3*,                                  /* An open database */
                                               const char *sql,                           /* SQL to be evaluated */
                                               int (*callback)(void*,int,char**,char**),  /* Callback function */
                                               void *,                                    /* 1st argument to callback */
                                               char **errmsg                              /* Error msg written here */
    );
    
    /*
     ** CAPI3REF: Result Codes
     ** KEYWORDS: {result code definitions}
     **
     ** Many SQLite functions return an integer result code from the set shown
     ** here in order to indicate success or failure.
     **
     ** New error codes may be added in future versions of SQLite.
     **
     ** See also: [extended result code definitions]
     */
#define SQLITE_OK           0   /* Successful result */
    /* beginning-of-error-codes */
#define SQLITE_ERROR        1   /* SQL error or missing database */
#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
#define SQLITE_PERM         3   /* Access permission denied */
#define SQLITE_ABORT        4   /* Callback routine requested an abort */
#define SQLITE_BUSY         5   /* The database file is locked */
#define SQLITE_LOCKED       6   /* A table in the database is locked */
#define SQLITE_NOMEM        7   /* A malloc() failed */
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
#define SQLITE_FULL        13   /* Insertion failed because database is full */
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
#define SQLITE_EMPTY       16   /* Database is empty */
#define SQLITE_SCHEMA      17   /* The database schema changed */
#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
#define SQLITE_MISMATCH    20   /* Data type mismatch */
#define SQLITE_MISUSE      21   /* Library used incorrectly */
#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
#define SQLITE_AUTH        23   /* Authorization denied */
#define SQLITE_FORMAT      24   /* Auxiliary database format error */
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
    /* end-of-error-codes */
    
    /*
     ** CAPI3REF: Extended Result Codes
     ** KEYWORDS: {extended result code definitions}
     **
     ** In its default configuration, SQLite API routines return one of 30 integer
     ** [result codes].  However, experience has shown that many of
     ** these result codes are too coarse-grained.  They do not provide as
     ** much information about problems as programmers might like.  In an effort to
     ** address this, newer versions of SQLite (version 3.3.8 and later) include
     ** support for additional result codes that provide more detailed information
     ** about errors. These [extended result codes] are enabled or disabled
     ** on a per database connection basis using the
     ** [sqlite3_extended_result_codes()] API.  Or, the extended code for
     ** the most recent error can be obtained using
     ** [sqlite3_extended_errcode()].
     */
#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
    
    /*
     ** CAPI3REF: Flags For File Open Operations
     **
     ** These bit values are intended for use in the
     ** 3rd parameter to the [sqlite3_open_v2()] interface and
     ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
     */
#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
    
    /* Reserved:                         0x00F00000 */
    
    /*
     ** CAPI3REF: Device Characteristics
     **
     ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
     ** object returns an integer which is a vector of these
     ** bit values expressing I/O characteristics of the mass storage
     ** device that holds the file that the [sqlite3_io_methods]
     ** refers to.
     **
     ** The SQLITE_IOCAP_ATOMIC property means that all writes of
     ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
     ** mean that writes of blocks that are nnn bytes in size and
     ** are aligned to an address which is an integer multiple of
     ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
     ** that when data is appended to a file, the data is appended
     ** first then the size of the file is extended, never the other
     ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
     ** information is written to disk in the same order as calls
     ** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
     ** after reboot following a crash or power loss, the only bytes in a
     ** file that were written at the application level might have changed
     ** and that adjacent bytes, even bytes within the same sector are
     ** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
     ** flag indicate that a file cannot be deleted when open.  The
     ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
     ** read-only media and cannot be changed even by processes with
     ** elevated privileges.
     */
#define SQLITE_IOCAP_ATOMIC                 0x00000001
#define SQLITE_IOCAP_ATOMIC512              0x00000002
#define SQLITE_IOCAP_ATOMIC1K               0x00000004
#define SQLITE_IOCAP_ATOMIC2K               0x00000008
#define SQLITE_IOCAP_ATOMIC4K               0x00000010
#define SQLITE_IOCAP_ATOMIC8K               0x00000020
#define SQLITE_IOCAP_ATOMIC16K              0x00000040
#define SQLITE_IOCAP_ATOMIC32K              0x00000080
#define SQLITE_IOCAP_ATOMIC64K              0x00000100
#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
#define SQLITE_IOCAP_IMMUTABLE              0x00002000
    
    /*
     ** CAPI3REF: File Locking Levels
     **
     ** SQLite uses one of these integer values as the second
     ** argument to calls it makes to the xLock() and xUnlock() methods
     ** of an [sqlite3_io_methods] object.
     */
#define SQLITE_LOCK_NONE          0
#define SQLITE_LOCK_SHARED        1
#define SQLITE_LOCK_RESERVED      2
#define SQLITE_LOCK_PENDING       3
#define SQLITE_LOCK_EXCLUSIVE     4
    
    /*
     ** CAPI3REF: Synchronization Type Flags
     **
     ** When SQLite invokes the xSync() method of an
     ** [sqlite3_io_methods] object it uses a combination of
     ** these integer values as the second argument.
     **
     ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
     ** sync operation only needs to flush data to mass storage.  Inode
     ** information need not be flushed. If the lower four bits of the flag
     ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
     ** If the lower four bits equal SQLITE_SYNC_FULL, that means
     ** to use Mac OS X style fullsync instead of fsync().
     **
     ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
     ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
     ** settings.  The [synchronous pragma] determines when calls to the
     ** xSync VFS method occur and applies uniformly across all platforms.
     ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
     ** energetic or rigorous or forceful the sync operations are and
     ** only make a difference on Mac OSX for the default SQLite code.
     ** (Third-party VFS implementations might also make the distinction
     ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
     ** operating systems natively supported by SQLite, only Mac OSX
     ** cares about the difference.)
     */
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010
    
    /*
     ** CAPI3REF: OS Interface Open File Handle
     **
     ** An [sqlite3_file] object represents an open file in the
     ** [sqlite3_vfs | OS interface layer].  Individual OS interface
     ** implementations will
     ** want to subclass this object by appending additional fields
     ** for their own use.  The pMethods entry is a pointer to an
     ** [sqlite3_io_methods] object that defines methods for performing
     ** I/O operations on the open file.
     */
    typedef struct sqlite3_file sqlite3_file;
    struct sqlite3_file {
        const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
    };
    
    /*
     ** CAPI3REF: OS Interface File Virtual Methods Object
     **
     ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
     ** [sqlite3_file] object (or, more commonly, a subclass of the
     ** [sqlite3_file] object) with a pointer to an instance of this object.
     ** This object defines the methods used to perform various operations
     ** against the open file represented by the [sqlite3_file] object.
     **
     ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
     ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
     ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
     ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
     ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
     ** to NULL.
     **
     ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
     ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
     ** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
     ** flag may be ORed in to indicate that only the data of the file
     ** and not its inode needs to be synced.
     **
     ** The integer values to xLock() and xUnlock() are one of
     ** <ul>
     ** <li> [SQLITE_LOCK_NONE],
     ** <li> [SQLITE_LOCK_SHARED],
     ** <li> [SQLITE_LOCK_RESERVED],
     ** <li> [SQLITE_LOCK_PENDING], or
     ** <li> [SQLITE_LOCK_EXCLUSIVE].
     ** </ul>
     ** xLock() increases the lock. xUnlock() decreases the lock.
     ** The xCheckReservedLock() method checks whether any database connection,
     ** either in this process or in some other process, is holding a RESERVED,
     ** PENDING, or EXCLUSIVE lock on the file.  It returns true
     ** if such a lock exists and false otherwise.
     **
     ** The xFileControl() method is a generic interface that allows custom
     ** VFS implementations to directly control an open file using the
     ** [sqlite3_file_control()] interface.  The second "op" argument is an
     ** integer opcode.  The third argument is a generic pointer intended to
     ** point to a structure that may contain arguments or space in which to
     ** write return values.  Potential uses for xFileControl() might be
     ** functions to enable blocking locks with timeouts, to change the
     ** locking strategy (for example to use dot-file locks), to inquire
     ** about the status of a lock, or to break stale locks.  The SQLite
     ** core reserves all opcodes less than 100 for its own use.
     ** A [file control opcodes | list of opcodes] less than 100 is available.
     ** Applications that define a custom xFileControl method should use opcodes
     ** greater than 100 to avoid conflicts.  VFS implementations should
     ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
     ** recognize.
     **
     ** The xSectorSize() method returns the sector size of the
     ** device that underlies the file.  The sector size is the
     ** minimum write that can be performed without disturbing
     ** other bytes in the file.  The xDeviceCharacteristics()
     ** method returns a bit vector describing behaviors of the
     ** underlying device:
     **
     ** <ul>
     ** <li> [SQLITE_IOCAP_ATOMIC]
     ** <li> [SQLITE_IOCAP_ATOMIC512]
     ** <li> [SQLITE_IOCAP_ATOMIC1K]
     ** <li> [SQLITE_IOCAP_ATOMIC2K]
     ** <li> [SQLITE_IOCAP_ATOMIC4K]
     ** <li> [SQLITE_IOCAP_ATOMIC8K]
     ** <li> [SQLITE_IOCAP_ATOMIC16K]
     ** <li> [SQLITE_IOCAP_ATOMIC32K]
     ** <li> [SQLITE_IOCAP_ATOMIC64K]
     ** <li> [SQLITE_IOCAP_SAFE_APPEND]
     ** <li> [SQLITE_IOCAP_SEQUENTIAL]
     ** </ul>
     **
     ** The SQLITE_IOCAP_ATOMIC property means that all writes of
     ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
     ** mean that writes of blocks that are nnn bytes in size and
     ** are aligned to an address which is an integer multiple of
     ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
     ** that when data is appended to a file, the data is appended
     ** first then the size of the file is extended, never the other
     ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
     ** information is written to disk in the same order as calls
     ** to xWrite().
     **
     ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
     ** in the unread portions of the buffer with zeros.  A VFS that
     ** fails to zero-fill short reads might seem to work.  However,
     ** failure to zero-fill short reads will eventually lead to
     ** database corruption.
     */
    typedef struct sqlite3_io_methods sqlite3_io_methods;
    struct sqlite3_io_methods {
        int iVersion;
        int (*xClose)(sqlite3_file*);
        int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
        int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
        int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
        int (*xSync)(sqlite3_file*, int flags);
        int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
        int (*xLock)(sqlite3_file*, int);
        int (*xUnlock)(sqlite3_file*, int);
        int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
        int (*xFileControl)(sqlite3_file*, int op, void *pArg);
        int (*xSectorSize)(sqlite3_file*);
        int (*xDeviceCharacteristics)(sqlite3_file*);
        /* Methods above are valid for version 1 */
        int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
        int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
        void (*xShmBarrier)(sqlite3_file*);
        int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
        /* Methods above are valid for version 2 */
        int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
        int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
        /* Methods above are valid for version 3 */
        /* Additional methods may be added in future releases */
    };
    
    /*
     ** CAPI3REF: Standard File Control Opcodes
     ** KEYWORDS: {file control opcodes} {file control opcode}
     **
     ** These integer constants are opcodes for the xFileControl method
     ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
     ** interface.
     **
     ** <ul>
     ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
     ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
     ** opcode causes the xFileControl method to write the current state of
     ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
     ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
     ** into an integer that the pArg argument points to. This capability
     ** is used during testing and is only available when the SQLITE_TEST
     ** compile-time option is used.
     **
     ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
     ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
     ** layer a hint of how large the database file will grow to be during the
     ** current transaction.  This hint is not guaranteed to be accurate but it
     ** is often close.  The underlying VFS might choose to preallocate database
     ** file space based on this hint in order to help writes to the database
     ** file run faster.
     **
     ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
     ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
     ** extends and truncates the database file in chunks of a size specified
     ** by the user. The fourth argument to [sqlite3_file_control()] should
     ** point to an integer (type int) containing the new chunk-size to use
     ** for the nominated database. Allocating database file space in large
     ** chunks (say 1MB at a time), may reduce file-system fragmentation and
     ** improve performance on some systems.
     **
     ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
     ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
     ** to the [sqlite3_file] object associated with a particular database
     ** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].
     **
     ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
     ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
     ** to the [sqlite3_file] object associated with the journal file (either
     ** the [rollback journal] or the [write-ahead log]) for a particular database
     ** connection.  See also [SQLITE_FCNTL_FILE_POINTER].
     **
     ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
     ** No longer in use.
     **
     ** <li>[[SQLITE_FCNTL_SYNC]]
     ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
     ** sent to the VFS immediately before the xSync method is invoked on a
     ** database file descriptor. Or, if the xSync method is not invoked
     ** because the user has configured SQLite with
     ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
     ** of the xSync method. In most cases, the pointer argument passed with
     ** this file-control is NULL. However, if the database file is being synced
     ** as part of a multi-database commit, the argument points to a nul-terminated
     ** string containing the transactions master-journal file name. VFSes that
     ** do not need this signal should silently ignore this opcode. Applications
     ** should not call [sqlite3_file_control()] with this opcode as doing so may
     ** disrupt the operation of the specialized VFSes that do require it.
     **
     ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
     ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
     ** and sent to the VFS after a transaction has been committed immediately
     ** but before the database is unlocked. VFSes that do not need this signal
     ** should silently ignore this opcode. Applications should not call
     ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
     ** operation of the specialized VFSes that do require it.
     **
     ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
     ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
     ** retry counts and intervals for certain disk I/O operations for the
     ** windows [VFS] in order to provide robustness in the presence of
     ** anti-virus programs.  By default, the windows VFS will retry file read,
     ** file write, and file delete operations up to 10 times, with a delay
     ** of 25 milliseconds before the first retry and with the delay increasing
     ** by an additional 25 milliseconds with each subsequent retry.  This
     ** opcode allows these two values (10 retries and 25 milliseconds of delay)
     ** to be adjusted.  The values are changed for all database connections
     ** within the same process.  The argument is a pointer to an array of two
     ** integers where the first integer i the new retry count and the second
     ** integer is the delay.  If either integer is negative, then the setting
     ** is not changed but instead the prior value of that setting is written
     ** into the array entry, allowing the current retry settings to be
     ** interrogated.  The zDbName parameter is ignored.
     **
     ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
     ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
     ** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
     ** write ahead log and shared memory files used for transaction control
     ** are automatically deleted when the latest connection to the database
     ** closes.  Setting persistent WAL mode causes those files to persist after
     ** close.  Persisting the files is useful when other processes that do not
     ** have write permission on the directory containing the database file want
     ** to read the database file, as the WAL and shared memory files must exist
     ** in order for the database to be readable.  The fourth parameter to
     ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
     ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
     ** WAL mode.  If the integer is -1, then it is overwritten with the current
     ** WAL persistence setting.
     **
     ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
     ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
     ** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
     ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
     ** xDeviceCharacteristics methods. The fourth parameter to
     ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
     ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
     ** mode.  If the integer is -1, then it is overwritten with the current
     ** zero-damage mode setting.
     **
     ** <li>[[SQLITE_FCNTL_OVERWRITE]]
     ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
     ** a write transaction to indicate that, unless it is rolled back for some
     ** reason, the entire database file will be overwritten by the current
     ** transaction. This is used by VACUUM operations.
     **
     ** <li>[[SQLITE_FCNTL_VFSNAME]]
     ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
     ** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
     ** final bottom-level VFS are written into memory obtained from
     ** [sqlite3_malloc()] and the result is stored in the char* variable
     ** that the fourth parameter of [sqlite3_file_control()] points to.
     ** The caller is responsible for freeing the memory when done.  As with
     ** all file-control actions, there is no guarantee that this will actually
     ** do anything.  Callers should initialize the char* variable to a NULL
     ** pointer in case this file-control is not implemented.  This file-control
     ** is intended for diagnostic use only.
     **
     ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
     ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
     ** [VFSes] currently in use.  ^(The argument X in
     ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
     ** of type "[sqlite3_vfs] **".  This opcodes will set *X
     ** to a pointer to the top-level VFS.)^
     ** ^When there are multiple VFS shims in the stack, this opcode finds the
     ** upper-most shim only.
     **
     ** <li>[[SQLITE_FCNTL_PRAGMA]]
     ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
     ** file control is sent to the open [sqlite3_file] object corresponding
     ** to the database file to which the pragma statement refers. ^The argument
     ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
     ** pointers to strings (char**) in which the second element of the array
     ** is the name of the pragma and the third element is the argument to the
     ** pragma or NULL if the pragma has no argument.  ^The handler for an
     ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
     ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
     ** or the equivalent and that string will become the result of the pragma or
     ** the error message if the pragma fails. ^If the
     ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
     ** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
     ** file control returns [SQLITE_OK], then the parser assumes that the
     ** VFS has handled the PRAGMA itself and the parser generates a no-op
     ** prepared statement if result string is NULL, or that returns a copy
     ** of the result string if the string is non-NULL.
     ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
     ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
     ** that the VFS encountered an error while handling the [PRAGMA] and the
     ** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
     ** file control occurs at the beginning of pragma statement analysis and so
     ** it is able to override built-in [PRAGMA] statements.
     **
     ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
     ** ^The [SQLITE_FCNTL_BUSYHANDLER]
     ** file-control may be invoked by SQLite on the database file handle
     ** shortly after it is opened in order to provide a custom VFS with access
     ** to the connections busy-handler callback. The argument is of type (void **)
     ** - an array of two (void *) values. The first (void *) actually points
     ** to a function of type (int (*)(void *)). In order to invoke the connections
     ** busy-handler, this function should be invoked with the second (void *) in
     ** the array as the only argument. If it returns non-zero, then the operation
     ** should be retried. If it returns zero, the custom VFS should abandon the
     ** current operation.
     **
     ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
     ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
     ** to have SQLite generate a
     ** temporary filename using the same algorithm that is followed to generate
     ** temporary filenames for TEMP tables and other internal uses.  The
     ** argument should be a char** which will be filled with the filename
     ** written into memory obtained from [sqlite3_malloc()].  The caller should
     ** invoke [sqlite3_free()] on the result to avoid a memory leak.
     **
     ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
     ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
     ** maximum number of bytes that will be used for memory-mapped I/O.
     ** The argument is a pointer to a value of type sqlite3_int64 that
     ** is an advisory maximum number of bytes in the file to memory map.  The
     ** pointer is overwritten with the old value.  The limit is not changed if
     ** the value originally pointed to is negative, and so the current limit
     ** can be queried by passing in a pointer to a negative number.  This
     ** file-control is used internally to implement [PRAGMA mmap_size].
     **
     ** <li>[[SQLITE_FCNTL_TRACE]]
     ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
     ** to the VFS about what the higher layers of the SQLite stack are doing.
     ** This file control is used by some VFS activity tracing [shims].
     ** The argument is a zero-terminated string.  Higher layers in the
     ** SQLite stack may generate instances of this file control if
     ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
     **
     ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
     ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
     ** pointer to an integer and it writes a boolean into that integer depending
     ** on whether or not the file has been renamed, moved, or deleted since it
     ** was first opened.
     **
     ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
     ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
     ** opcode causes the xFileControl method to swap the file handle with the one
     ** pointed to by the pArg argument.  This capability is used during testing
     ** and only needs to be supported when SQLITE_TEST is defined.
     **
     ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
     ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
     ** be advantageous to block on the next WAL lock if the lock is not immediately
     ** available.  The WAL subsystem issues this signal during rare
     ** circumstances in order to fix a problem with priority inversion.
     ** Applications should <em>not</em> use this file-control.
     **
     ** <li>[[SQLITE_FCNTL_ZIPVFS]]
     ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
     ** VFS should return SQLITE_NOTFOUND for this opcode.
     **
     ** <li>[[SQLITE_FCNTL_RBU]]
     ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
     ** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
     ** this opcode.
     ** </ul>
     */
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
#define SQLITE_FCNTL_LAST_ERRNO              4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
#define SQLITE_FCNTL_FILE_POINTER            7
#define SQLITE_FCNTL_SYNC_OMITTED            8
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14
#define SQLITE_FCNTL_BUSYHANDLER            15
#define SQLITE_FCNTL_TEMPFILENAME           16
#define SQLITE_FCNTL_MMAP_SIZE              18
#define SQLITE_FCNTL_TRACE                  19
#define SQLITE_FCNTL_HAS_MOVED              20
#define SQLITE_FCNTL_SYNC                   21
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
#define SQLITE_FCNTL_WAL_BLOCK              24
#define SQLITE_FCNTL_ZIPVFS                 25
#define SQLITE_FCNTL_RBU                    26
#define SQLITE_FCNTL_VFS_POINTER            27
#define SQLITE_FCNTL_JOURNAL_POINTER        28
    
    /* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO
    
    
    /*
     ** CAPI3REF: Mutex Handle
     **
     ** The mutex module within SQLite defines [sqlite3_mutex] to be an
     ** abstract type for a mutex object.  The SQLite core never looks
     ** at the internal representation of an [sqlite3_mutex].  It only
     ** deals with pointers to the [sqlite3_mutex] object.
     **
     ** Mutexes are created using [sqlite3_mutex_alloc()].
     */
    typedef struct sqlite3_mutex sqlite3_mutex;
    
    /*
     ** CAPI3REF: OS Interface Object
     **
     ** An instance of the sqlite3_vfs object defines the interface between
     ** the SQLite core and the underlying operating system.  The "vfs"
     ** in the name of the object stands for "virtual file system".  See
     ** the [VFS | VFS documentation] for further information.
     **
     ** The value of the iVersion field is initially 1 but may be larger in
     ** future versions of SQLite.  Additional fields may be appended to this
     ** object when the iVersion value is increased.  Note that the structure
     ** of the sqlite3_vfs object changes in the transaction between
     ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
     ** modified.
     **
     ** The szOsFile field is the size of the subclassed [sqlite3_file]
     ** structure used by this VFS.  mxPathname is the maximum length of
     ** a pathname in this VFS.
     **
     ** Registered sqlite3_vfs objects are kept on a linked list formed by
     ** the pNext pointer.  The [sqlite3_vfs_register()]
     ** and [sqlite3_vfs_unregister()] interfaces manage this list
     ** in a thread-safe way.  The [sqlite3_vfs_find()] interface
     ** searches the list.  Neither the application code nor the VFS
     ** implementation should use the pNext pointer.
     **
     ** The pNext field is the only field in the sqlite3_vfs
     ** structure that SQLite will ever modify.  SQLite will only access
     ** or modify this field while holding a particular static mutex.
     ** The application should never modify anything within the sqlite3_vfs
     ** object once the object has been registered.
     **
     ** The zName field holds the name of the VFS module.  The name must
     ** be unique across all VFS modules.
     **
     ** [[sqlite3_vfs.xOpen]]
     ** ^SQLite guarantees that the zFilename parameter to xOpen
     ** is either a NULL pointer or string obtained
     ** from xFullPathname() with an optional suffix added.
     ** ^If a suffix is added to the zFilename parameter, it will
     ** consist of a single "-" character followed by no more than
     ** 11 alphanumeric and/or "-" characters.
     ** ^SQLite further guarantees that
     ** the string will be valid and unchanged until xClose() is
     ** called. Because of the previous sentence,
     ** the [sqlite3_file] can safely store a pointer to the
     ** filename if it needs to remember the filename for some reason.
     ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
     ** must invent its own temporary name for the file.  ^Whenever the
     ** xFilename parameter is NULL it will also be the case that the
     ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
     **
     ** The flags argument to xOpen() includes all bits set in
     ** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
     ** or [sqlite3_open16()] is used, then flags includes at least
     ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
     ** If xOpen() opens a file read-only then it sets *pOutFlags to
     ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
     **
     ** ^(SQLite will also add one of the following flags to the xOpen()
     ** call, depending on the object being opened:
     **
     ** <ul>
     ** <li>  [SQLITE_OPEN_MAIN_DB]
     ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
     ** <li>  [SQLITE_OPEN_TEMP_DB]
     ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
     ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
     ** <li>  [SQLITE_OPEN_SUBJOURNAL]
     ** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
     ** <li>  [SQLITE_OPEN_WAL]
     ** </ul>)^
     **
     ** The file I/O implementation can use the object type flags to
     ** change the way it deals with files.  For example, an application
     ** that does not care about crash recovery or rollback might make
     ** the open of a journal file a no-op.  Writes to this journal would
     ** also be no-ops, and any attempt to read the journal would return
     ** SQLITE_IOERR.  Or the implementation might recognize that a database
     ** file will be doing page-aligned sector reads and writes in a random
     ** order and set up its I/O subsystem accordingly.
     **
     ** SQLite might also add one of the following flags to the xOpen method:
     **
     ** <ul>
     ** <li> [SQLITE_OPEN_DELETEONCLOSE]
     ** <li> [SQLITE_OPEN_EXCLUSIVE]
     ** </ul>
     **
     ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
     ** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
     ** will be set for TEMP databases and their journals, transient
     ** databases, and subjournals.
     **
     ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
     ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
     ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
     ** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
     ** SQLITE_OPEN_CREATE, is used to indicate that file should always
     ** be created, and that it is an error if it already exists.
     ** It is <i>not</i> used to indicate the file should be opened
     ** for exclusive access.
     **
     ** ^At least szOsFile bytes of memory are allocated by SQLite
     ** to hold the  [sqlite3_file] structure passed as the third
     ** argument to xOpen.  The xOpen method does not have to
     ** allocate the structure; it should just fill it in.  Note that
     ** the xOpen method must set the sqlite3_file.pMethods to either
     ** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
     ** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
     ** element will be valid after xOpen returns regardless of the success
     ** or failure of the xOpen call.
     **
     ** [[sqlite3_vfs.xAccess]]
     ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
     ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
     ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
     ** to test whether a file is at least readable.   The file can be a
     ** directory.
     **
     ** ^SQLite will always allocate at least mxPathname+1 bytes for the
     ** output buffer xFullPathname.  The exact size of the output buffer
     ** is also passed as a parameter to both  methods. If the output buffer
     ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
     ** handled as a fatal error by SQLite, vfs implementations should endeavor
     ** to prevent this by setting mxPathname to a sufficiently large value.
     **
     ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
     ** interfaces are not strictly a part of the filesystem, but they are
     ** included in the VFS structure for completeness.
     ** The xRandomness() function attempts to return nBytes bytes
     ** of good-quality randomness into zOut.  The return value is
     ** the actual number of bytes of randomness obtained.
     ** The xSleep() method causes the calling thread to sleep for at
     ** least the number of microseconds given.  ^The xCurrentTime()
     ** method returns a Julian Day Number for the current date and time as
     ** a floating point value.
     ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
     ** Day Number multiplied by 86400000 (the number of milliseconds in
     ** a 24-hour day).
     ** ^SQLite will use the xCurrentTimeInt64() method to get the current
     ** date and time if that method is available (if iVersion is 2 or
     ** greater and the function pointer is not NULL) and will fall back
     ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
     **
     ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
     ** are not used by the SQLite core.  These optional interfaces are provided
     ** by some VFSes to facilitate testing of the VFS code. By overriding
     ** system calls with functions under its control, a test program can
     ** simulate faults and error conditions that would otherwise be difficult
     ** or impossible to induce.  The set of system calls that can be overridden
     ** varies from one VFS to another, and from one version of the same VFS to the
     ** next.  Applications that use these interfaces must be prepared for any
     ** or all of these interfaces to be NULL or for their behavior to change
     ** from one release to the next.  Applications must not attempt to access
     ** any of these methods if the iVersion of the VFS is less than 3.
     */
    typedef struct sqlite3_vfs sqlite3_vfs;
    typedef void (*sqlite3_syscall_ptr)(void);
    struct sqlite3_vfs {
        int iVersion;            /* Structure version number (currently 3) */
        int szOsFile;            /* Size of subclassed sqlite3_file */
        int mxPathname;          /* Maximum file pathname length */
        sqlite3_vfs *pNext;      /* Next registered VFS */
        const char *zName;       /* Name of this virtual file system */
        void *pAppData;          /* Pointer to application-specific data */
        int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
                     int flags, int *pOutFlags);
        int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
        int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
        int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
        void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
        void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
        void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
        void (*xDlClose)(sqlite3_vfs*, void*);
        int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
        int (*xSleep)(sqlite3_vfs*, int microseconds);
        int (*xCurrentTime)(sqlite3_vfs*, double*);
        int (*xGetLastError)(sqlite3_vfs*, int, char *);
        /*
         ** The methods above are in version 1 of the sqlite_vfs object
         ** definition.  Those that follow are added in version 2 or later
         */
        int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
        /*
         ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
         ** Those below are for version 3 and greater.
         */
        int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
        sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
        const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
        /*
         ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
         ** New fields may be appended in figure versions.  The iVersion
         ** value will increment whenever this happens.
         */
    };
    
    /*
     ** CAPI3REF: Flags for the xAccess VFS method
     **
     ** These integer constants can be used as the third parameter to
     ** the xAccess method of an [sqlite3_vfs] object.  They determine
     ** what kind of permissions the xAccess method is looking for.
     ** With SQLITE_ACCESS_EXISTS, the xAccess method
     ** simply checks whether the file exists.
     ** With SQLITE_ACCESS_READWRITE, the xAccess method
     ** checks whether the named directory is both readable and writable
     ** (in other words, if files can be added, removed, and renamed within
     ** the directory).
     ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
     ** [temp_store_directory pragma], though this could change in a future
     ** release of SQLite.
     ** With SQLITE_ACCESS_READ, the xAccess method
     ** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
     ** currently unused, though it might be used in a future release of
     ** SQLite.
     */
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
#define SQLITE_ACCESS_READ      2   /* Unused */
    
    /*
     ** CAPI3REF: Flags for the xShmLock VFS method
     **
     ** These integer constants define the various locking operations
     ** allowed by the xShmLock method of [sqlite3_io_methods].  The
     ** following are the only legal combinations of flags to the
     ** xShmLock method:
     **
     ** <ul>
     ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
     ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
     ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
     ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
     ** </ul>
     **
     ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
     ** was given on the corresponding lock.
     **
     ** The xShmLock method can transition between unlocked and SHARED or
     ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
     ** and EXCLUSIVE.
     */
#define SQLITE_SHM_UNLOCK       1
#define SQLITE_SHM_LOCK         2
#define SQLITE_SHM_SHARED       4
#define SQLITE_SHM_EXCLUSIVE    8
    
    /*
     ** CAPI3REF: Maximum xShmLock index
     **
     ** The xShmLock method on [sqlite3_io_methods] may use values
     ** between 0 and this upper bound as its "offset" argument.
     ** The SQLite core will never attempt to acquire or release a
     ** lock outside of this range
     */
#define SQLITE_SHM_NLOCK        8
    
    
    /*
     ** CAPI3REF: Initialize The SQLite Library
     **
     ** ^The sqlite3_initialize() routine initializes the
     ** SQLite library.  ^The sqlite3_shutdown() routine
     ** deallocates any resources that were allocated by sqlite3_initialize().
     ** These routines are designed to aid in process initialization and
     ** shutdown on embedded systems.  Workstation applications using
     ** SQLite normally do not need to invoke either of these routines.
     **
     ** A call to sqlite3_initialize() is an "effective" call if it is
     ** the first time sqlite3_initialize() is invoked during the lifetime of
     ** the process, or if it is the first time sqlite3_initialize() is invoked
     ** following a call to sqlite3_shutdown().  ^(Only an effective call
     ** of sqlite3_initialize() does any initialization.  All other calls
     ** are harmless no-ops.)^
     **
     ** A call to sqlite3_shutdown() is an "effective" call if it is the first
     ** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
     ** an effective call to sqlite3_shutdown() does any deinitialization.
     ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
     **
     ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
     ** is not.  The sqlite3_shutdown() interface must only be called from a
     ** single thread.  All open [database connections] must be closed and all
     ** other SQLite resources must be deallocated prior to invoking
     ** sqlite3_shutdown().
     **
     ** Among other things, ^sqlite3_initialize() will invoke
     ** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
     ** will invoke sqlite3_os_end().
     **
     ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
     ** ^If for some reason, sqlite3_initialize() is unable to initialize
     ** the library (perhaps it is unable to allocate a needed resource such
     ** as a mutex) it returns an [error code] other than [SQLITE_OK].
     **
     ** ^The sqlite3_initialize() routine is called internally by many other
     ** SQLite interfaces so that an application usually does not need to
     ** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
     ** calls sqlite3_initialize() so the SQLite library will be automatically
     ** initialized when [sqlite3_open()] is called if it has not be initialized
     ** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
     ** compile-time option, then the automatic calls to sqlite3_initialize()
     ** are omitted and the application must call sqlite3_initialize() directly
     ** prior to using any other SQLite interface.  For maximum portability,
     ** it is recommended that applications always invoke sqlite3_initialize()
     ** directly prior to using any other SQLite interface.  Future releases
     ** of SQLite may require this.  In other words, the behavior exhibited
     ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
     ** default behavior in some future release of SQLite.
     **
     ** The sqlite3_os_init() routine does operating-system specific
     ** initialization of the SQLite library.  The sqlite3_os_end()
     ** routine undoes the effect of sqlite3_os_init().  Typical tasks
     ** performed by these routines include allocation or deallocation
     ** of static resources, initialization of global variables,
     ** setting up a default [sqlite3_vfs] module, or setting up
     ** a default configuration using [sqlite3_config()].
     **
     ** The application should never invoke either sqlite3_os_init()
     ** or sqlite3_os_end() directly.  The application should only invoke
     ** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
     ** interface is called automatically by sqlite3_initialize() and
     ** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
     ** implementations for sqlite3_os_init() and sqlite3_os_end()
     ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
     ** When [custom builds | built for other platforms]
     ** (using the [SQLITE_OS_OTHER=1] compile-time
     ** option) the application must supply a suitable implementation for
     ** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
     ** implementation of sqlite3_os_init() or sqlite3_os_end()
     ** must return [SQLITE_OK] on success and some other [error code] upon
     ** failure.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void);
    SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void);
    SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void);
    SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void);
    
    /*
     ** CAPI3REF: Configuring The SQLite Library
     **
     ** The sqlite3_config() interface is used to make global configuration
     ** changes to SQLite in order to tune SQLite to the specific needs of
     ** the application.  The default configuration is recommended for most
     ** applications and so this routine is usually not necessary.  It is
     ** provided to support rare applications with unusual needs.
     **
     ** <b>The sqlite3_config() interface is not threadsafe. The application
     ** must ensure that no other SQLite interfaces are invoked by other
     ** threads while sqlite3_config() is running.</b>
     **
     ** The sqlite3_config() interface
     ** may only be invoked prior to library initialization using
     ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
     ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
     ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
     ** Note, however, that ^sqlite3_config() can be called as part of the
     ** implementation of an application-defined [sqlite3_os_init()].
     **
     ** The first argument to sqlite3_config() is an integer
     ** [configuration option] that determines
     ** what property of SQLite is to be configured.  Subsequent arguments
     ** vary depending on the [configuration option]
     ** in the first argument.
     **
     ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
     ** ^If the option is unknown or SQLite is unable to set the option
     ** then this routine returns a non-zero [error code].
     */
    SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...);
    
    /*
     ** CAPI3REF: Configure database connections
     ** METHOD: sqlite3
     **
     ** The sqlite3_db_config() interface is used to make configuration
     ** changes to a [database connection].  The interface is similar to
     ** [sqlite3_config()] except that the changes apply to a single
     ** [database connection] (specified in the first argument).
     **
     ** The second argument to sqlite3_db_config(D,V,...)  is the
     ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
     ** that indicates what aspect of the [database connection] is being configured.
     ** Subsequent arguments vary depending on the configuration verb.
     **
     ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
     ** the call is considered successful.
     */
    SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...);
    
    /*
     ** CAPI3REF: Memory Allocation Routines
     **
     ** An instance of this object defines the interface between SQLite
     ** and low-level memory allocation routines.
     **
     ** This object is used in only one place in the SQLite interface.
     ** A pointer to an instance of this object is the argument to
     ** [sqlite3_config()] when the configuration option is
     ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
     ** By creating an instance of this object
     ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
     ** during configuration, an application can specify an alternative
     ** memory allocation subsystem for SQLite to use for all of its
     ** dynamic memory needs.
     **
     ** Note that SQLite comes with several [built-in memory allocators]
     ** that are perfectly adequate for the overwhelming majority of applications
     ** and that this object is only useful to a tiny minority of applications
     ** with specialized memory allocation requirements.  This object is
     ** also used during testing of SQLite in order to specify an alternative
     ** memory allocator that simulates memory out-of-memory conditions in
     ** order to verify that SQLite recovers gracefully from such
     ** conditions.
     **
     ** The xMalloc, xRealloc, and xFree methods must work like the
     ** malloc(), realloc() and free() functions from the standard C library.
     ** ^SQLite guarantees that the second argument to
     ** xRealloc is always a value returned by a prior call to xRoundup.
     **
     ** xSize should return the allocated size of a memory allocation
     ** previously obtained from xMalloc or xRealloc.  The allocated size
     ** is always at least as big as the requested size but may be larger.
     **
     ** The xRoundup method returns what would be the allocated size of
     ** a memory allocation given a particular requested size.  Most memory
     ** allocators round up memory allocations at least to the next multiple
     ** of 8.  Some allocators round up to a larger multiple or to a power of 2.
     ** Every memory allocation request coming in through [sqlite3_malloc()]
     ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
     ** that causes the corresponding memory allocation to fail.
     **
     ** The xInit method initializes the memory allocator.  For example,
     ** it might allocate any require mutexes or initialize internal data
     ** structures.  The xShutdown method is invoked (indirectly) by
     ** [sqlite3_shutdown()] and should deallocate any resources acquired
     ** by xInit.  The pAppData pointer is used as the only parameter to
     ** xInit and xShutdown.
     **
     ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
     ** the xInit method, so the xInit method need not be threadsafe.  The
     ** xShutdown method is only called from [sqlite3_shutdown()] so it does
     ** not need to be threadsafe either.  For all other methods, SQLite
     ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
     ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
     ** it is by default) and so the methods are automatically serialized.
     ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
     ** methods must be threadsafe or else make their own arrangements for
     ** serialization.
     **
     ** SQLite will never invoke xInit() more than once without an intervening
     ** call to xShutdown().
     */
    typedef struct sqlite3_mem_methods sqlite3_mem_methods;
    struct sqlite3_mem_methods {
        void *(*xMalloc)(int);         /* Memory allocation function */
        void (*xFree)(void*);          /* Free a prior allocation */
        void *(*xRealloc)(void*,int);  /* Resize an allocation */
        int (*xSize)(void*);           /* Return the size of an allocation */
        int (*xRoundup)(int);          /* Round up request size to allocation size */
        int (*xInit)(void*);           /* Initialize the memory allocator */
        void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
        void *pAppData;                /* Argument to xInit() and xShutdown() */
    };
    
    /*
     ** CAPI3REF: Configuration Options
     ** KEYWORDS: {configuration option}
     **
     ** These constants are the available integer configuration options that
     ** can be passed as the first argument to the [sqlite3_config()] interface.
     **
     ** New configuration options may be added in future releases of SQLite.
     ** Existing configuration options might be discontinued.  Applications
     ** should check the return code from [sqlite3_config()] to make sure that
     ** the call worked.  The [sqlite3_config()] interface will return a
     ** non-zero [error code] if a discontinued or unsupported configuration option
     ** is invoked.
     **
     ** <dl>
     ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
     ** <dd>There are no arguments to this option.  ^This option sets the
     ** [threading mode] to Single-thread.  In other words, it disables
     ** all mutexing and puts SQLite into a mode where it can only be used
     ** by a single thread.   ^If SQLite is compiled with
     ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
     ** it is not possible to change the [threading mode] from its default
     ** value of Single-thread and so [sqlite3_config()] will return
     ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
     ** configuration option.</dd>
     **
     ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
     ** <dd>There are no arguments to this option.  ^This option sets the
     ** [threading mode] to Multi-thread.  In other words, it disables
     ** mutexing on [database connection] and [prepared statement] objects.
     ** The application is responsible for serializing access to
     ** [database connections] and [prepared statements].  But other mutexes
     ** are enabled so that SQLite will be safe to use in a multi-threaded
     ** environment as long as no two threads attempt to use the same
     ** [database connection] at the same time.  ^If SQLite is compiled with
     ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
     ** it is not possible to set the Multi-thread [threading mode] and
     ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
     ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
     **
     ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
     ** <dd>There are no arguments to this option.  ^This option sets the
     ** [threading mode] to Serialized. In other words, this option enables
     ** all mutexes including the recursive
     ** mutexes on [database connection] and [prepared statement] objects.
     ** In this mode (which is the default when SQLite is compiled with
     ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
     ** to [database connections] and [prepared statements] so that the
     ** application is free to use the same [database connection] or the
     ** same [prepared statement] in different threads at the same time.
     ** ^If SQLite is compiled with
     ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
     ** it is not possible to set the Serialized [threading mode] and
     ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
     ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
     **
     ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
     ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
     ** a pointer to an instance of the [sqlite3_mem_methods] structure.
     ** The argument specifies
     ** alternative low-level memory allocation routines to be used in place of
     ** the memory allocation routines built into SQLite.)^ ^SQLite makes
     ** its own private copy of the content of the [sqlite3_mem_methods] structure
     ** before the [sqlite3_config()] call returns.</dd>
     **
     ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
     ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
     ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
     ** The [sqlite3_mem_methods]
     ** structure is filled with the currently defined memory allocation routines.)^
     ** This option can be used to overload the default memory allocation
     ** routines with a wrapper that simulations memory allocation failure or
     ** tracks memory usage, for example. </dd>
     **
     ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
     ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
     ** interpreted as a boolean, which enables or disables the collection of
     ** memory allocation statistics. ^(When memory allocation statistics are
     ** disabled, the following SQLite interfaces become non-operational:
     **   <ul>
     **   <li> [sqlite3_memory_used()]
     **   <li> [sqlite3_memory_highwater()]
     **   <li> [sqlite3_soft_heap_limit64()]
     **   <li> [sqlite3_status64()]
     **   </ul>)^
     ** ^Memory allocation statistics are enabled by default unless SQLite is
     ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
     ** allocation statistics are disabled by default.
     ** </dd>
     **
     ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
     ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
     ** that SQLite can use for scratch memory.  ^(There are three arguments
     ** to SQLITE_CONFIG_SCRATCH:  A pointer an 8-byte
     ** aligned memory buffer from which the scratch allocations will be
     ** drawn, the size of each scratch allocation (sz),
     ** and the maximum number of scratch allocations (N).)^
     ** The first argument must be a pointer to an 8-byte aligned buffer
     ** of at least sz*N bytes of memory.
     ** ^SQLite will not use more than one scratch buffers per thread.
     ** ^SQLite will never request a scratch buffer that is more than 6
     ** times the database page size.
     ** ^If SQLite needs needs additional
     ** scratch memory beyond what is provided by this configuration option, then
     ** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
     ** ^When the application provides any amount of scratch memory using
     ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
     ** [sqlite3_malloc|heap allocations].
     ** This can help [Robson proof|prevent memory allocation failures] due to heap
     ** fragmentation in low-memory embedded systems.
     ** </dd>
     **
     ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
     ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
     ** that SQLite can use for the database page cache with the default page
     ** cache implementation.
     ** This configuration option is a no-op if an application-define page
     ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
     ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
     ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
     ** and the number of cache lines (N).
     ** The sz argument should be the size of the largest database page
     ** (a power of two between 512 and 65536) plus some extra bytes for each
     ** page header.  ^The number of extra bytes needed by the page header
     ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
     ** ^It is harmless, apart from the wasted memory,
     ** for the sz parameter to be larger than necessary.  The pMem
     ** argument must be either a NULL pointer or a pointer to an 8-byte
     ** aligned block of memory of at least sz*N bytes, otherwise
     ** subsequent behavior is undefined.
     ** ^When pMem is not NULL, SQLite will strive to use the memory provided
     ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
     ** a page cache line is larger than sz bytes or if all of the pMem buffer
     ** is exhausted.
     ** ^If pMem is NULL and N is non-zero, then each database connection
     ** does an initial bulk allocation for page cache memory
     ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
     ** of -1024*N bytes if N is negative, . ^If additional
     ** page cache memory is needed beyond what is provided by the initial
     ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
     ** additional cache line. </dd>
     **
     ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
     ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
     ** that SQLite will use for all of its dynamic memory allocation needs
     ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
     ** [SQLITE_CONFIG_PAGECACHE].
     ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
     ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
     ** [SQLITE_ERROR] if invoked otherwise.
     ** ^There are three arguments to SQLITE_CONFIG_HEAP:
     ** An 8-byte aligned pointer to the memory,
     ** the number of bytes in the memory buffer, and the minimum allocation size.
     ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
     ** to using its default memory allocator (the system malloc() implementation),
     ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
     ** memory pointer is not NULL then the alternative memory
     ** allocator is engaged to handle all of SQLites memory allocation needs.
     ** The first pointer (the memory pointer) must be aligned to an 8-byte
     ** boundary or subsequent behavior of SQLite will be undefined.
     ** The minimum allocation size is capped at 2**12. Reasonable values
     ** for the minimum allocation size are 2**5 through 2**8.</dd>
     **
     ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
     ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
     ** pointer to an instance of the [sqlite3_mutex_methods] structure.
     ** The argument specifies alternative low-level mutex routines to be used
     ** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
     ** the content of the [sqlite3_mutex_methods] structure before the call to
     ** [sqlite3_config()] returns. ^If SQLite is compiled with
     ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
     ** the entire mutexing subsystem is omitted from the build and hence calls to
     ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
     ** return [SQLITE_ERROR].</dd>
     **
     ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
     ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
     ** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
     ** [sqlite3_mutex_methods]
     ** structure is filled with the currently defined mutex routines.)^
     ** This option can be used to overload the default mutex allocation
     ** routines with a wrapper used to track mutex usage for performance
     ** profiling or testing, for example.   ^If SQLite is compiled with
     ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
     ** the entire mutexing subsystem is omitted from the build and hence calls to
     ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
     ** return [SQLITE_ERROR].</dd>
     **
     ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
     ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
     ** the default size of lookaside memory on each [database connection].
     ** The first argument is the
     ** size of each lookaside buffer slot and the second is the number of
     ** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE
     ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
     ** option to [sqlite3_db_config()] can be used to change the lookaside
     ** configuration on individual connections.)^ </dd>
     **
     ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
     ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
     ** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
     ** the interface to a custom page cache implementation.)^
     ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
     **
     ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
     ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
     ** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
     ** the current page cache implementation into that object.)^ </dd>
     **
     ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
     ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
     ** global [error log].
     ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
     ** function with a call signature of void(*)(void*,int,const char*),
     ** and a pointer to void. ^If the function pointer is not NULL, it is
     ** invoked by [sqlite3_log()] to process each logging event.  ^If the
     ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
     ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
     ** passed through as the first parameter to the application-defined logger
     ** function whenever that function is invoked.  ^The second parameter to
     ** the logger function is a copy of the first parameter to the corresponding
     ** [sqlite3_log()] call and is intended to be a [result code] or an
     ** [extended result code].  ^The third parameter passed to the logger is
     ** log message after formatting via [sqlite3_snprintf()].
     ** The SQLite logging interface is not reentrant; the logger function
     ** supplied by the application must not invoke any SQLite interface.
     ** In a multi-threaded application, the application-defined logger
     ** function must be threadsafe. </dd>
     **
     ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
     ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
     ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
     ** then URI handling is globally disabled.)^ ^If URI handling is globally
     ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
     ** [sqlite3_open16()] or
     ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
     ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
     ** connection is opened. ^If it is globally disabled, filenames are
     ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
     ** database connection is opened. ^(By default, URI handling is globally
     ** disabled. The default value may be changed by compiling with the
     ** [SQLITE_USE_URI] symbol defined.)^
     **
     ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
     ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
     ** argument which is interpreted as a boolean in order to enable or disable
     ** the use of covering indices for full table scans in the query optimizer.
     ** ^The default setting is determined
     ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
     ** if that compile-time option is omitted.
     ** The ability to disable the use of covering indices for full table scans
     ** is because some incorrectly coded legacy applications might malfunction
     ** when the optimization is enabled.  Providing the ability to
     ** disable the optimization allows the older, buggy application code to work
     ** without change even with newer versions of SQLite.
     **
     ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
     ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
     ** <dd> These options are obsolete and should not be used by new code.
     ** They are retained for backwards compatibility but are now no-ops.
     ** </dd>
     **
     ** [[SQLITE_CONFIG_SQLLOG]]
     ** <dt>SQLITE_CONFIG_SQLLOG
     ** <dd>This option is only available if sqlite is compiled with the
     ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
     ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
     ** The second should be of type (void*). The callback is invoked by the library
     ** in three separate circumstances, identified by the value passed as the
     ** fourth parameter. If the fourth parameter is 0, then the database connection
     ** passed as the second argument has just been opened. The third argument
     ** points to a buffer containing the name of the main database file. If the
     ** fourth parameter is 1, then the SQL statement that the third parameter
     ** points to has just been executed. Or, if the fourth parameter is 2, then
     ** the connection being passed as the second parameter is being closed. The
     ** third parameter is passed NULL In this case.  An example of using this
     ** configuration option can be seen in the "test_sqllog.c" source file in
     ** the canonical SQLite source tree.</dd>
     **
     ** [[SQLITE_CONFIG_MMAP_SIZE]]
     ** <dt>SQLITE_CONFIG_MMAP_SIZE
     ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
     ** that are the default mmap size limit (the default setting for
     ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
     ** ^The default setting can be overridden by each database connection using
     ** either the [PRAGMA mmap_size] command, or by using the
     ** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
     ** will be silently truncated if necessary so that it does not exceed the
     ** compile-time maximum mmap size set by the
     ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
     ** ^If either argument to this option is negative, then that argument is
     ** changed to its compile-time default.
     **
     ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
     ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
     ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
     ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
     ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
     ** that specifies the maximum size of the created heap.
     **
     ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
     ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
     ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
     ** is a pointer to an integer and writes into that integer the number of extra
     ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
     ** The amount of extra space required can change depending on the compiler,
     ** target platform, and SQLite version.
     **
     ** [[SQLITE_CONFIG_PMASZ]]
     ** <dt>SQLITE_CONFIG_PMASZ
     ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
     ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
     ** sorter to that integer.  The default minimum PMA Size is set by the
     ** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched
     ** to help with sort operations when multithreaded sorting
     ** is enabled (using the [PRAGMA threads] command) and the amount of content
     ** to be sorted exceeds the page size times the minimum of the
     ** [PRAGMA cache_size] setting and this value.
     ** </dl>
     */
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
    /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
#define SQLITE_CONFIG_PCACHE       14  /* no-op */
#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
#define SQLITE_CONFIG_URI          17  /* int */
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
#define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
    
    /*
     ** CAPI3REF: Database Connection Configuration Options
     **
     ** These constants are the available integer configuration options that
     ** can be passed as the second argument to the [sqlite3_db_config()] interface.
     **
     ** New configuration options may be added in future releases of SQLite.
     ** Existing configuration options might be discontinued.  Applications
     ** should check the return code from [sqlite3_db_config()] to make sure that
     ** the call worked.  ^The [sqlite3_db_config()] interface will return a
     ** non-zero [error code] if a discontinued or unsupported configuration option
     ** is invoked.
     **
     ** <dl>
     ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
     ** <dd> ^This option takes three additional arguments that determine the
     ** [lookaside memory allocator] configuration for the [database connection].
     ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
     ** pointer to a memory buffer to use for lookaside memory.
     ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
     ** may be NULL in which case SQLite will allocate the
     ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
     ** size of each lookaside buffer slot.  ^The third argument is the number of
     ** slots.  The size of the buffer in the first argument must be greater than
     ** or equal to the product of the second and third arguments.  The buffer
     ** must be aligned to an 8-byte boundary.  ^If the second argument to
     ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
     ** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
     ** configuration for a database connection can only be changed when that
     ** connection is not currently using lookaside memory, or in other words
     ** when the "current value" returned by
     ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
     ** Any attempt to change the lookaside memory configuration when lookaside
     ** memory is in use leaves the configuration unchanged and returns
     ** [SQLITE_BUSY].)^</dd>
     **
     ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
     ** <dd> ^This option is used to enable or disable the enforcement of
     ** [foreign key constraints].  There should be two additional arguments.
     ** The first argument is an integer which is 0 to disable FK enforcement,
     ** positive to enable FK enforcement or negative to leave FK enforcement
     ** unchanged.  The second parameter is a pointer to an integer into which
     ** is written 0 or 1 to indicate whether FK enforcement is off or on
     ** following this call.  The second parameter may be a NULL pointer, in
     ** which case the FK enforcement setting is not reported back. </dd>
     **
     ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
     ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
     ** There should be two additional arguments.
     ** The first argument is an integer which is 0 to disable triggers,
     ** positive to enable triggers or negative to leave the setting unchanged.
     ** The second parameter is a pointer to an integer into which
     ** is written 0 or 1 to indicate whether triggers are disabled or enabled
     ** following this call.  The second parameter may be a NULL pointer, in
     ** which case the trigger setting is not reported back. </dd>
     **
     ** </dl>
     */
#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
    
    
    /*
     ** CAPI3REF: Enable Or Disable Extended Result Codes
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_extended_result_codes() routine enables or disables the
     ** [extended result codes] feature of SQLite. ^The extended result
     ** codes are disabled by default for historical compatibility.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff);
    
    /*
     ** CAPI3REF: Last Insert Rowid
     ** METHOD: sqlite3
     **
     ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
     ** has a unique 64-bit signed
     ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
     ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
     ** names are not also used by explicitly declared columns. ^If
     ** the table has a column of type [INTEGER PRIMARY KEY] then that column
     ** is another alias for the rowid.
     **
     ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
     ** most recent successful [INSERT] into a rowid table or [virtual table]
     ** on database connection D.
     ** ^Inserts into [WITHOUT ROWID] tables are not recorded.
     ** ^If no successful [INSERT]s into rowid tables
     ** have ever occurred on the database connection D,
     ** then sqlite3_last_insert_rowid(D) returns zero.
     **
     ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
     ** method, then this routine will return the [rowid] of the inserted
     ** row as long as the trigger or virtual table method is running.
     ** But once the trigger or virtual table method ends, the value returned
     ** by this routine reverts to what it was before the trigger or virtual
     ** table method began.)^
     **
     ** ^An [INSERT] that fails due to a constraint violation is not a
     ** successful [INSERT] and does not change the value returned by this
     ** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
     ** and INSERT OR ABORT make no changes to the return value of this
     ** routine when their insertion fails.  ^(When INSERT OR REPLACE
     ** encounters a constraint violation, it does not fail.  The
     ** INSERT continues to completion after deleting rows that caused
     ** the constraint problem so INSERT OR REPLACE will always change
     ** the return value of this interface.)^
     **
     ** ^For the purposes of this routine, an [INSERT] is considered to
     ** be successful even if it is subsequently rolled back.
     **
     ** This function is accessible to SQL statements via the
     ** [last_insert_rowid() SQL function].
     **
     ** If a separate thread performs a new [INSERT] on the same
     ** database connection while the [sqlite3_last_insert_rowid()]
     ** function is running and thus changes the last insert [rowid],
     ** then the value returned by [sqlite3_last_insert_rowid()] is
     ** unpredictable and might not equal either the old or the new
     ** last insert [rowid].
     */
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*);
    
    /*
     ** CAPI3REF: Count The Number Of Rows Modified
     ** METHOD: sqlite3
     **
     ** ^This function returns the number of rows modified, inserted or
     ** deleted by the most recently completed INSERT, UPDATE or DELETE
     ** statement on the database connection specified by the only parameter.
     ** ^Executing any other type of SQL statement does not modify the value
     ** returned by this function.
     **
     ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
     ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
     ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
     **
     ** Changes to a view that are intercepted by
     ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
     ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
     ** DELETE statement run on a view is always zero. Only changes made to real
     ** tables are counted.
     **
     ** Things are more complicated if the sqlite3_changes() function is
     ** executed while a trigger program is running. This may happen if the
     ** program uses the [changes() SQL function], or if some other callback
     ** function invokes sqlite3_changes() directly. Essentially:
     **
     ** <ul>
     **   <li> ^(Before entering a trigger program the value returned by
     **        sqlite3_changes() function is saved. After the trigger program
     **        has finished, the original value is restored.)^
     **
     **   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
     **        statement sets the value returned by sqlite3_changes()
     **        upon completion as normal. Of course, this value will not include
     **        any changes performed by sub-triggers, as the sqlite3_changes()
     **        value will be saved and restored after each sub-trigger has run.)^
     ** </ul>
     **
     ** ^This means that if the changes() SQL function (or similar) is used
     ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
     ** returns the value as set when the calling statement began executing.
     ** ^If it is used by the second or subsequent such statement within a trigger
     ** program, the value returned reflects the number of rows modified by the
     ** previous INSERT, UPDATE or DELETE statement within the same trigger.
     **
     ** See also the [sqlite3_total_changes()] interface, the
     ** [count_changes pragma], and the [changes() SQL function].
     **
     ** If a separate thread makes changes on the same database connection
     ** while [sqlite3_changes()] is running then the value returned
     ** is unpredictable and not meaningful.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*);
    
    /*
     ** CAPI3REF: Total Number Of Rows Modified
     ** METHOD: sqlite3
     **
     ** ^This function returns the total number of rows inserted, modified or
     ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
     ** since the database connection was opened, including those executed as
     ** part of trigger programs. ^Executing any other type of SQL statement
     ** does not affect the value returned by sqlite3_total_changes().
     **
     ** ^Changes made as part of [foreign key actions] are included in the
     ** count, but those made as part of REPLACE constraint resolution are
     ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
     ** are not counted.
     **
     ** See also the [sqlite3_changes()] interface, the
     ** [count_changes pragma], and the [total_changes() SQL function].
     **
     ** If a separate thread makes changes on the same database connection
     ** while [sqlite3_total_changes()] is running then the value
     ** returned is unpredictable and not meaningful.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*);
    
    /*
     ** CAPI3REF: Interrupt A Long-Running Query
     ** METHOD: sqlite3
     **
     ** ^This function causes any pending database operation to abort and
     ** return at its earliest opportunity. This routine is typically
     ** called in response to a user action such as pressing "Cancel"
     ** or Ctrl-C where the user wants a long query operation to halt
     ** immediately.
     **
     ** ^It is safe to call this routine from a thread different from the
     ** thread that is currently running the database operation.  But it
     ** is not safe to call this routine with a [database connection] that
     ** is closed or might close before sqlite3_interrupt() returns.
     **
     ** ^If an SQL operation is very nearly finished at the time when
     ** sqlite3_interrupt() is called, then it might not have an opportunity
     ** to be interrupted and might continue to completion.
     **
     ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
     ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
     ** that is inside an explicit transaction, then the entire transaction
     ** will be rolled back automatically.
     **
     ** ^The sqlite3_interrupt(D) call is in effect until all currently running
     ** SQL statements on [database connection] D complete.  ^Any new SQL statements
     ** that are started after the sqlite3_interrupt() call and before the
     ** running statements reaches zero are interrupted as if they had been
     ** running prior to the sqlite3_interrupt() call.  ^New SQL statements
     ** that are started after the running statement count reaches zero are
     ** not effected by the sqlite3_interrupt().
     ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
     ** SQL statements is a no-op and has no effect on SQL statements
     ** that are started after the sqlite3_interrupt() call returns.
     **
     ** If the database connection closes while [sqlite3_interrupt()]
     ** is running then bad things will likely happen.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*);
    
    /*
     ** CAPI3REF: Determine If An SQL Statement Is Complete
     **
     ** These routines are useful during command-line input to determine if the
     ** currently entered text seems to form a complete SQL statement or
     ** if additional input is needed before sending the text into
     ** SQLite for parsing.  ^These routines return 1 if the input string
     ** appears to be a complete SQL statement.  ^A statement is judged to be
     ** complete if it ends with a semicolon token and is not a prefix of a
     ** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
     ** string literals or quoted identifier names or comments are not
     ** independent tokens (they are part of the token in which they are
     ** embedded) and thus do not count as a statement terminator.  ^Whitespace
     ** and comments that follow the final semicolon are ignored.
     **
     ** ^These routines return 0 if the statement is incomplete.  ^If a
     ** memory allocation fails, then SQLITE_NOMEM is returned.
     **
     ** ^These routines do not parse the SQL statements thus
     ** will not detect syntactically incorrect SQL.
     **
     ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
     ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
     ** automatically by sqlite3_complete16().  If that initialization fails,
     ** then the return value from sqlite3_complete16() will be non-zero
     ** regardless of whether or not the input SQL is complete.)^
     **
     ** The input to [sqlite3_complete()] must be a zero-terminated
     ** UTF-8 string.
     **
     ** The input to [sqlite3_complete16()] must be a zero-terminated
     ** UTF-16 string in native byte order.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql);
    SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql);
    
    /*
     ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
     ** KEYWORDS: {busy-handler callback} {busy handler}
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
     ** that might be invoked with argument P whenever
     ** an attempt is made to access a database table associated with
     ** [database connection] D when another thread
     ** or process has the table locked.
     ** The sqlite3_busy_handler() interface is used to implement
     ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
     **
     ** ^If the busy callback is NULL, then [SQLITE_BUSY]
     ** is returned immediately upon encountering the lock.  ^If the busy callback
     ** is not NULL, then the callback might be invoked with two arguments.
     **
     ** ^The first argument to the busy handler is a copy of the void* pointer which
     ** is the third argument to sqlite3_busy_handler().  ^The second argument to
     ** the busy handler callback is the number of times that the busy handler has
     ** been invoked previously for the same locking event.  ^If the
     ** busy callback returns 0, then no additional attempts are made to
     ** access the database and [SQLITE_BUSY] is returned
     ** to the application.
     ** ^If the callback returns non-zero, then another attempt
     ** is made to access the database and the cycle repeats.
     **
     ** The presence of a busy handler does not guarantee that it will be invoked
     ** when there is lock contention. ^If SQLite determines that invoking the busy
     ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
     ** to the application instead of invoking the
     ** busy handler.
     ** Consider a scenario where one process is holding a read lock that
     ** it is trying to promote to a reserved lock and
     ** a second process is holding a reserved lock that it is trying
     ** to promote to an exclusive lock.  The first process cannot proceed
     ** because it is blocked by the second and the second process cannot
     ** proceed because it is blocked by the first.  If both processes
     ** invoke the busy handlers, neither will make any progress.  Therefore,
     ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
     ** will induce the first process to release its read lock and allow
     ** the second process to proceed.
     **
     ** ^The default busy callback is NULL.
     **
     ** ^(There can only be a single busy handler defined for each
     ** [database connection].  Setting a new busy handler clears any
     ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
     ** or evaluating [PRAGMA busy_timeout=N] will change the
     ** busy handler and thus clear any previously set busy handler.
     **
     ** The busy callback should not take any actions which modify the
     ** database connection that invoked the busy handler.  In other words,
     ** the busy handler is not reentrant.  Any such actions
     ** result in undefined behavior.
     **
     ** A busy handler must not close the database connection
     ** or [prepared statement] that invoked the busy handler.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
    
    /*
     ** CAPI3REF: Set A Busy Timeout
     ** METHOD: sqlite3
     **
     ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
     ** for a specified amount of time when a table is locked.  ^The handler
     ** will sleep multiple times until at least "ms" milliseconds of sleeping
     ** have accumulated.  ^After at least "ms" milliseconds of sleeping,
     ** the handler returns 0 which causes [sqlite3_step()] to return
     ** [SQLITE_BUSY].
     **
     ** ^Calling this routine with an argument less than or equal to zero
     ** turns off all busy handlers.
     **
     ** ^(There can only be a single busy handler for a particular
     ** [database connection] at any given moment.  If another busy handler
     ** was defined  (using [sqlite3_busy_handler()]) prior to calling
     ** this routine, that other busy handler is cleared.)^
     **
     ** See also:  [PRAGMA busy_timeout]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms);
    
    /*
     ** CAPI3REF: Convenience Routines For Running Queries
     ** METHOD: sqlite3
     **
     ** This is a legacy interface that is preserved for backwards compatibility.
     ** Use of this interface is not recommended.
     **
     ** Definition: A <b>result table</b> is memory data structure created by the
     ** [sqlite3_get_table()] interface.  A result table records the
     ** complete query results from one or more queries.
     **
     ** The table conceptually has a number of rows and columns.  But
     ** these numbers are not part of the result table itself.  These
     ** numbers are obtained separately.  Let N be the number of rows
     ** and M be the number of columns.
     **
     ** A result table is an array of pointers to zero-terminated UTF-8 strings.
     ** There are (N+1)*M elements in the array.  The first M pointers point
     ** to zero-terminated strings that  contain the names of the columns.
     ** The remaining entries all point to query results.  NULL values result
     ** in NULL pointers.  All other values are in their UTF-8 zero-terminated
     ** string representation as returned by [sqlite3_column_text()].
     **
     ** A result table might consist of one or more memory allocations.
     ** It is not safe to pass a result table directly to [sqlite3_free()].
     ** A result table should be deallocated using [sqlite3_free_table()].
     **
     ** ^(As an example of the result table format, suppose a query result
     ** is as follows:
     **
     ** <blockquote><pre>
     **        Name        | Age
     **        -----------------------
     **        Alice       | 43
     **        Bob         | 28
     **        Cindy       | 21
     ** </pre></blockquote>
     **
     ** There are two column (M==2) and three rows (N==3).  Thus the
     ** result table has 8 entries.  Suppose the result table is stored
     ** in an array names azResult.  Then azResult holds this content:
     **
     ** <blockquote><pre>
     **        azResult&#91;0] = "Name";
     **        azResult&#91;1] = "Age";
     **        azResult&#91;2] = "Alice";
     **        azResult&#91;3] = "43";
     **        azResult&#91;4] = "Bob";
     **        azResult&#91;5] = "28";
     **        azResult&#91;6] = "Cindy";
     **        azResult&#91;7] = "21";
     ** </pre></blockquote>)^
     **
     ** ^The sqlite3_get_table() function evaluates one or more
     ** semicolon-separated SQL statements in the zero-terminated UTF-8
     ** string of its 2nd parameter and returns a result table to the
     ** pointer given in its 3rd parameter.
     **
     ** After the application has finished with the result from sqlite3_get_table(),
     ** it must pass the result table pointer to sqlite3_free_table() in order to
     ** release the memory that was malloced.  Because of the way the
     ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
     ** function must not try to call [sqlite3_free()] directly.  Only
     ** [sqlite3_free_table()] is able to release the memory properly and safely.
     **
     ** The sqlite3_get_table() interface is implemented as a wrapper around
     ** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
     ** to any internal data structures of SQLite.  It uses only the public
     ** interface defined here.  As a consequence, errors that occur in the
     ** wrapper layer outside of the internal [sqlite3_exec()] call are not
     ** reflected in subsequent calls to [sqlite3_errcode()] or
     ** [sqlite3_errmsg()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_get_table(
                                                    sqlite3 *db,          /* An open database */
                                                    const char *zSql,     /* SQL to be evaluated */
                                                    char ***pazResult,    /* Results of the query */
                                                    int *pnRow,           /* Number of result rows written here */
                                                    int *pnColumn,        /* Number of result columns written here */
                                                    char **pzErrmsg       /* Error msg written here */
    );
    SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result);
    
    /*
     ** CAPI3REF: Formatted String Printing Functions
     **
     ** These routines are work-alikes of the "printf()" family of functions
     ** from the standard C library.
     ** These routines understand most of the common K&R formatting options,
     ** plus some additional non-standard formats, detailed below.
     ** Note that some of the more obscure formatting options from recent
     ** C-library standards are omitted from this implementation.
     **
     ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
     ** results into memory obtained from [sqlite3_malloc()].
     ** The strings returned by these two routines should be
     ** released by [sqlite3_free()].  ^Both routines return a
     ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
     ** memory to hold the resulting string.
     **
     ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
     ** the standard C library.  The result is written into the
     ** buffer supplied as the second parameter whose size is given by
     ** the first parameter. Note that the order of the
     ** first two parameters is reversed from snprintf().)^  This is an
     ** historical accident that cannot be fixed without breaking
     ** backwards compatibility.  ^(Note also that sqlite3_snprintf()
     ** returns a pointer to its buffer instead of the number of
     ** characters actually written into the buffer.)^  We admit that
     ** the number of characters written would be a more useful return
     ** value but we cannot change the implementation of sqlite3_snprintf()
     ** now without breaking compatibility.
     **
     ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
     ** guarantees that the buffer is always zero-terminated.  ^The first
     ** parameter "n" is the total size of the buffer, including space for
     ** the zero terminator.  So the longest string that can be completely
     ** written will be n-1 characters.
     **
     ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
     **
     ** These routines all implement some additional formatting
     ** options that are useful for constructing SQL statements.
     ** All of the usual printf() formatting options apply.  In addition, there
     ** is are "%q", "%Q", "%w" and "%z" options.
     **
     ** ^(The %q option works like %s in that it substitutes a nul-terminated
     ** string from the argument list.  But %q also doubles every '\'' character.
     ** %q is designed for use inside a string literal.)^  By doubling each '\''
     ** character it escapes that character and allows it to be inserted into
     ** the string.
     **
     ** For example, assume the string variable zText contains text as follows:
     **
     ** <blockquote><pre>
     **  char *zText = "It's a happy day!";
     ** </pre></blockquote>
     **
     ** One can use this text in an SQL statement as follows:
     **
     ** <blockquote><pre>
     **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
     **  sqlite3_exec(db, zSQL, 0, 0, 0);
     **  sqlite3_free(zSQL);
     ** </pre></blockquote>
     **
     ** Because the %q format string is used, the '\'' character in zText
     ** is escaped and the SQL generated is as follows:
     **
     ** <blockquote><pre>
     **  INSERT INTO table1 VALUES('It''s a happy day!')
     ** </pre></blockquote>
     **
     ** This is correct.  Had we used %s instead of %q, the generated SQL
     ** would have looked like this:
     **
     ** <blockquote><pre>
     **  INSERT INTO table1 VALUES('It's a happy day!');
     ** </pre></blockquote>
     **
     ** This second example is an SQL syntax error.  As a general rule you should
     ** always use %q instead of %s when inserting text into a string literal.
     **
     ** ^(The %Q option works like %q except it also adds single quotes around
     ** the outside of the total string.  Additionally, if the parameter in the
     ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
     ** single quotes).)^  So, for example, one could say:
     **
     ** <blockquote><pre>
     **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
     **  sqlite3_exec(db, zSQL, 0, 0, 0);
     **  sqlite3_free(zSQL);
     ** </pre></blockquote>
     **
     ** The code above will render a correct SQL statement in the zSQL
     ** variable even if the zText variable is a NULL pointer.
     **
     ** ^(The "%w" formatting option is like "%q" except that it expects to
     ** be contained within double-quotes instead of single quotes, and it
     ** escapes the double-quote character instead of the single-quote
     ** character.)^  The "%w" formatting option is intended for safely inserting
     ** table and column names into a constructed SQL statement.
     **
     ** ^(The "%z" formatting option works like "%s" but with the
     ** addition that after the string has been read and copied into
     ** the result, [sqlite3_free()] is called on the input string.)^
     */
    SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...);
    SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list);
    SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...);
    SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list);
    
    /*
     ** CAPI3REF: Memory Allocation Subsystem
     **
     ** The SQLite core uses these three routines for all of its own
     ** internal memory allocation needs. "Core" in the previous sentence
     ** does not include operating-system specific VFS implementation.  The
     ** Windows VFS uses native malloc() and free() for some operations.
     **
     ** ^The sqlite3_malloc() routine returns a pointer to a block
     ** of memory at least N bytes in length, where N is the parameter.
     ** ^If sqlite3_malloc() is unable to obtain sufficient free
     ** memory, it returns a NULL pointer.  ^If the parameter N to
     ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
     ** a NULL pointer.
     **
     ** ^The sqlite3_malloc64(N) routine works just like
     ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
     ** of a signed 32-bit integer.
     **
     ** ^Calling sqlite3_free() with a pointer previously returned
     ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
     ** that it might be reused.  ^The sqlite3_free() routine is
     ** a no-op if is called with a NULL pointer.  Passing a NULL pointer
     ** to sqlite3_free() is harmless.  After being freed, memory
     ** should neither be read nor written.  Even reading previously freed
     ** memory might result in a segmentation fault or other severe error.
     ** Memory corruption, a segmentation fault, or other severe error
     ** might result if sqlite3_free() is called with a non-NULL pointer that
     ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
     **
     ** ^The sqlite3_realloc(X,N) interface attempts to resize a
     ** prior memory allocation X to be at least N bytes.
     ** ^If the X parameter to sqlite3_realloc(X,N)
     ** is a NULL pointer then its behavior is identical to calling
     ** sqlite3_malloc(N).
     ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
     ** negative then the behavior is exactly the same as calling
     ** sqlite3_free(X).
     ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
     ** of at least N bytes in size or NULL if insufficient memory is available.
     ** ^If M is the size of the prior allocation, then min(N,M) bytes
     ** of the prior allocation are copied into the beginning of buffer returned
     ** by sqlite3_realloc(X,N) and the prior allocation is freed.
     ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
     ** prior allocation is not freed.
     **
     ** ^The sqlite3_realloc64(X,N) interfaces works the same as
     ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
     ** of a 32-bit signed integer.
     **
     ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
     ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
     ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
     ** ^The value returned by sqlite3_msize(X) might be larger than the number
     ** of bytes requested when X was allocated.  ^If X is a NULL pointer then
     ** sqlite3_msize(X) returns zero.  If X points to something that is not
     ** the beginning of memory allocation, or if it points to a formerly
     ** valid memory allocation that has now been freed, then the behavior
     ** of sqlite3_msize(X) is undefined and possibly harmful.
     **
     ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
     ** sqlite3_malloc64(), and sqlite3_realloc64()
     ** is always aligned to at least an 8 byte boundary, or to a
     ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
     ** option is used.
     **
     ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
     ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
     ** implementation of these routines to be omitted.  That capability
     ** is no longer provided.  Only built-in memory allocators can be used.
     **
     ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
     ** the system malloc() and free() directly when converting
     ** filenames between the UTF-8 encoding used by SQLite
     ** and whatever filename encoding is used by the particular Windows
     ** installation.  Memory allocation errors were detected, but
     ** they were reported back as [SQLITE_CANTOPEN] or
     ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
     **
     ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
     ** must be either NULL or else pointers obtained from a prior
     ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
     ** not yet been released.
     **
     ** The application must not read or write any part of
     ** a block of memory after it has been released using
     ** [sqlite3_free()] or [sqlite3_realloc()].
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int);
    SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64);
    SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int);
    SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64);
    SQLITE_API void SQLITE_STDCALL sqlite3_free(void*);
    SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*);
    
    /*
     ** CAPI3REF: Memory Allocator Statistics
     **
     ** SQLite provides these two interfaces for reporting on the status
     ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
     ** routines, which form the built-in memory allocation subsystem.
     **
     ** ^The [sqlite3_memory_used()] routine returns the number of bytes
     ** of memory currently outstanding (malloced but not freed).
     ** ^The [sqlite3_memory_highwater()] routine returns the maximum
     ** value of [sqlite3_memory_used()] since the high-water mark
     ** was last reset.  ^The values returned by [sqlite3_memory_used()] and
     ** [sqlite3_memory_highwater()] include any overhead
     ** added by SQLite in its implementation of [sqlite3_malloc()],
     ** but not overhead added by the any underlying system library
     ** routines that [sqlite3_malloc()] may call.
     **
     ** ^The memory high-water mark is reset to the current value of
     ** [sqlite3_memory_used()] if and only if the parameter to
     ** [sqlite3_memory_highwater()] is true.  ^The value returned
     ** by [sqlite3_memory_highwater(1)] is the high-water mark
     ** prior to the reset.
     */
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void);
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag);
    
    /*
     ** CAPI3REF: Pseudo-Random Number Generator
     **
     ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
     ** select random [ROWID | ROWIDs] when inserting new records into a table that
     ** already uses the largest possible [ROWID].  The PRNG is also used for
     ** the build-in random() and randomblob() SQL functions.  This interface allows
     ** applications to access the same PRNG for other purposes.
     **
     ** ^A call to this routine stores N bytes of randomness into buffer P.
     ** ^The P parameter can be a NULL pointer.
     **
     ** ^If this routine has not been previously called or if the previous
     ** call had N less than one or a NULL pointer for P, then the PRNG is
     ** seeded using randomness obtained from the xRandomness method of
     ** the default [sqlite3_vfs] object.
     ** ^If the previous call to this routine had an N of 1 or more and a
     ** non-NULL P then the pseudo-randomness is generated
     ** internally and without recourse to the [sqlite3_vfs] xRandomness
     ** method.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P);
    
    /*
     ** CAPI3REF: Compile-Time Authorization Callbacks
     ** METHOD: sqlite3
     **
     ** ^This routine registers an authorizer callback with a particular
     ** [database connection], supplied in the first argument.
     ** ^The authorizer callback is invoked as SQL statements are being compiled
     ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
     ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
     ** points during the compilation process, as logic is being created
     ** to perform various actions, the authorizer callback is invoked to
     ** see if those actions are allowed.  ^The authorizer callback should
     ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
     ** specific action but allow the SQL statement to continue to be
     ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
     ** rejected with an error.  ^If the authorizer callback returns
     ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
     ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
     ** the authorizer will fail with an error message.
     **
     ** When the callback returns [SQLITE_OK], that means the operation
     ** requested is ok.  ^When the callback returns [SQLITE_DENY], the
     ** [sqlite3_prepare_v2()] or equivalent call that triggered the
     ** authorizer will fail with an error message explaining that
     ** access is denied.
     **
     ** ^The first parameter to the authorizer callback is a copy of the third
     ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
     ** to the callback is an integer [SQLITE_COPY | action code] that specifies
     ** the particular action to be authorized. ^The third through sixth parameters
     ** to the callback are zero-terminated strings that contain additional
     ** details about the action to be authorized.
     **
     ** ^If the action code is [SQLITE_READ]
     ** and the callback returns [SQLITE_IGNORE] then the
     ** [prepared statement] statement is constructed to substitute
     ** a NULL value in place of the table column that would have
     ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
     ** return can be used to deny an untrusted user access to individual
     ** columns of a table.
     ** ^If the action code is [SQLITE_DELETE] and the callback returns
     ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
     ** [truncate optimization] is disabled and all rows are deleted individually.
     **
     ** An authorizer is used when [sqlite3_prepare | preparing]
     ** SQL statements from an untrusted source, to ensure that the SQL statements
     ** do not try to access data they are not allowed to see, or that they do not
     ** try to execute malicious statements that damage the database.  For
     ** example, an application may allow a user to enter arbitrary
     ** SQL queries for evaluation by a database.  But the application does
     ** not want the user to be able to make arbitrary changes to the
     ** database.  An authorizer could then be put in place while the
     ** user-entered SQL is being [sqlite3_prepare | prepared] that
     ** disallows everything except [SELECT] statements.
     **
     ** Applications that need to process SQL from untrusted sources
     ** might also consider lowering resource limits using [sqlite3_limit()]
     ** and limiting database size using the [max_page_count] [PRAGMA]
     ** in addition to using an authorizer.
     **
     ** ^(Only a single authorizer can be in place on a database connection
     ** at a time.  Each call to sqlite3_set_authorizer overrides the
     ** previous call.)^  ^Disable the authorizer by installing a NULL callback.
     ** The authorizer is disabled by default.
     **
     ** The authorizer callback must not do anything that will modify
     ** the database connection that invoked the authorizer callback.
     ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
     ** database connections for the meaning of "modify" in this paragraph.
     **
     ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
     ** statement might be re-prepared during [sqlite3_step()] due to a
     ** schema change.  Hence, the application should ensure that the
     ** correct authorizer callback remains in place during the [sqlite3_step()].
     **
     ** ^Note that the authorizer callback is invoked only during
     ** [sqlite3_prepare()] or its variants.  Authorization is not
     ** performed during statement evaluation in [sqlite3_step()], unless
     ** as stated in the previous paragraph, sqlite3_step() invokes
     ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer(
                                                         sqlite3*,
                                                         int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
                                                         void *pUserData
                                                         );
    
    /*
     ** CAPI3REF: Authorizer Return Codes
     **
     ** The [sqlite3_set_authorizer | authorizer callback function] must
     ** return either [SQLITE_OK] or one of these two constants in order
     ** to signal SQLite whether or not the action is permitted.  See the
     ** [sqlite3_set_authorizer | authorizer documentation] for additional
     ** information.
     **
     ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
     ** returned from the [sqlite3_vtab_on_conflict()] interface.
     */
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
    
    /*
     ** CAPI3REF: Authorizer Action Codes
     **
     ** The [sqlite3_set_authorizer()] interface registers a callback function
     ** that is invoked to authorize certain SQL statement actions.  The
     ** second parameter to the callback is an integer code that specifies
     ** what action is being authorized.  These are the integer action codes that
     ** the authorizer callback may be passed.
     **
     ** These action code values signify what kind of operation is to be
     ** authorized.  The 3rd and 4th parameters to the authorization
     ** callback function will be parameters or NULL depending on which of these
     ** codes is used as the second parameter.  ^(The 5th parameter to the
     ** authorizer callback is the name of the database ("main", "temp",
     ** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
     ** is the name of the inner-most trigger or view that is responsible for
     ** the access attempt or NULL if this access attempt is directly from
     ** top-level SQL code.
     */
    /******************************************* 3rd ************ 4th ***********/
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
#define SQLITE_DELETE                9   /* Table Name      NULL            */
#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
#define SQLITE_INSERT               18   /* Table Name      NULL            */
#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
#define SQLITE_READ                 20   /* Table Name      Column Name     */
#define SQLITE_SELECT               21   /* NULL            NULL            */
#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
#define SQLITE_ATTACH               24   /* Filename        NULL            */
#define SQLITE_DETACH               25   /* Database Name   NULL            */
#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
#define SQLITE_REINDEX              27   /* Index Name      NULL            */
#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
#define SQLITE_COPY                  0   /* No longer used */
#define SQLITE_RECURSIVE            33   /* NULL            NULL            */
    
    /*
     ** CAPI3REF: Tracing And Profiling Functions
     ** METHOD: sqlite3
     **
     ** These routines register callback functions that can be used for
     ** tracing and profiling the execution of SQL statements.
     **
     ** ^The callback function registered by sqlite3_trace() is invoked at
     ** various times when an SQL statement is being run by [sqlite3_step()].
     ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
     ** SQL statement text as the statement first begins executing.
     ** ^(Additional sqlite3_trace() callbacks might occur
     ** as each triggered subprogram is entered.  The callbacks for triggers
     ** contain a UTF-8 SQL comment that identifies the trigger.)^
     **
     ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
     ** the length of [bound parameter] expansion in the output of sqlite3_trace().
     **
     ** ^The callback function registered by sqlite3_profile() is invoked
     ** as each SQL statement finishes.  ^The profile callback contains
     ** the original statement text and an estimate of wall-clock time
     ** of how long that statement took to run.  ^The profile callback
     ** time is in units of nanoseconds, however the current implementation
     ** is only capable of millisecond resolution so the six least significant
     ** digits in the time are meaningless.  Future versions of SQLite
     ** might provide greater resolution on the profiler callback.  The
     ** sqlite3_profile() function is considered experimental and is
     ** subject to change in future versions of SQLite.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
    SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*,
                                                                        void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
    
    /*
     ** CAPI3REF: Query Progress Callbacks
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
     ** function X to be invoked periodically during long running calls to
     ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
     ** database connection D.  An example use for this
     ** interface is to keep a GUI updated during a large query.
     **
     ** ^The parameter P is passed through as the only parameter to the
     ** callback function X.  ^The parameter N is the approximate number of
     ** [virtual machine instructions] that are evaluated between successive
     ** invocations of the callback X.  ^If N is less than one then the progress
     ** handler is disabled.
     **
     ** ^Only a single progress handler may be defined at one time per
     ** [database connection]; setting a new progress handler cancels the
     ** old one.  ^Setting parameter X to NULL disables the progress handler.
     ** ^The progress handler is also disabled by setting N to a value less
     ** than 1.
     **
     ** ^If the progress callback returns non-zero, the operation is
     ** interrupted.  This feature can be used to implement a
     ** "Cancel" button on a GUI progress dialog box.
     **
     ** The progress handler callback must not do anything that will modify
     ** the database connection that invoked the progress handler.
     ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
     ** database connections for the meaning of "modify" in this paragraph.
     **
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
    
    /*
     ** CAPI3REF: Opening A New Database Connection
     ** CONSTRUCTOR: sqlite3
     **
     ** ^These routines open an SQLite database file as specified by the
     ** filename argument. ^The filename argument is interpreted as UTF-8 for
     ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
     ** order for sqlite3_open16(). ^(A [database connection] handle is usually
     ** returned in *ppDb, even if an error occurs.  The only exception is that
     ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
     ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
     ** object.)^ ^(If the database is opened (and/or created) successfully, then
     ** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
     ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
     ** an English language description of the error following a failure of any
     ** of the sqlite3_open() routines.
     **
     ** ^The default encoding will be UTF-8 for databases created using
     ** sqlite3_open() or sqlite3_open_v2().  ^The default encoding for databases
     ** created using sqlite3_open16() will be UTF-16 in the native byte order.
     **
     ** Whether or not an error occurs when it is opened, resources
     ** associated with the [database connection] handle should be released by
     ** passing it to [sqlite3_close()] when it is no longer required.
     **
     ** The sqlite3_open_v2() interface works like sqlite3_open()
     ** except that it accepts two additional parameters for additional control
     ** over the new database connection.  ^(The flags parameter to
     ** sqlite3_open_v2() can take one of
     ** the following three values, optionally combined with the
     ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
     ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
     **
     ** <dl>
     ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
     ** <dd>The database is opened in read-only mode.  If the database does not
     ** already exist, an error is returned.</dd>)^
     **
     ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
     ** <dd>The database is opened for reading and writing if possible, or reading
     ** only if the file is write protected by the operating system.  In either
     ** case the database must already exist, otherwise an error is returned.</dd>)^
     **
     ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
     ** <dd>The database is opened for reading and writing, and is created if
     ** it does not already exist. This is the behavior that is always used for
     ** sqlite3_open() and sqlite3_open16().</dd>)^
     ** </dl>
     **
     ** If the 3rd parameter to sqlite3_open_v2() is not one of the
     ** combinations shown above optionally combined with other
     ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
     ** then the behavior is undefined.
     **
     ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
     ** opens in the multi-thread [threading mode] as long as the single-thread
     ** mode has not been set at compile-time or start-time.  ^If the
     ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
     ** in the serialized [threading mode] unless single-thread was
     ** previously selected at compile-time or start-time.
     ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
     ** eligible to use [shared cache mode], regardless of whether or not shared
     ** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
     ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
     ** participate in [shared cache mode] even if it is enabled.
     **
     ** ^The fourth parameter to sqlite3_open_v2() is the name of the
     ** [sqlite3_vfs] object that defines the operating system interface that
     ** the new database connection should use.  ^If the fourth parameter is
     ** a NULL pointer then the default [sqlite3_vfs] object is used.
     **
     ** ^If the filename is ":memory:", then a private, temporary in-memory database
     ** is created for the connection.  ^This in-memory database will vanish when
     ** the database connection is closed.  Future versions of SQLite might
     ** make use of additional special filenames that begin with the ":" character.
     ** It is recommended that when a database filename actually does begin with
     ** a ":" character you should prefix the filename with a pathname such as
     ** "./" to avoid ambiguity.
     **
     ** ^If the filename is an empty string, then a private, temporary
     ** on-disk database will be created.  ^This private database will be
     ** automatically deleted as soon as the database connection is closed.
     **
     ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
     **
     ** ^If [URI filename] interpretation is enabled, and the filename argument
     ** begins with "file:", then the filename is interpreted as a URI. ^URI
     ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
     ** set in the fourth argument to sqlite3_open_v2(), or if it has
     ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
     ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
     ** As of SQLite version 3.7.7, URI filename interpretation is turned off
     ** by default, but future releases of SQLite might enable URI filename
     ** interpretation by default.  See "[URI filenames]" for additional
     ** information.
     **
     ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
     ** authority, then it must be either an empty string or the string
     ** "localhost". ^If the authority is not an empty string or "localhost", an
     ** error is returned to the caller. ^The fragment component of a URI, if
     ** present, is ignored.
     **
     ** ^SQLite uses the path component of the URI as the name of the disk file
     ** which contains the database. ^If the path begins with a '/' character,
     ** then it is interpreted as an absolute path. ^If the path does not begin
     ** with a '/' (meaning that the authority section is omitted from the URI)
     ** then the path is interpreted as a relative path.
     ** ^(On windows, the first component of an absolute path
     ** is a drive specification (e.g. "C:").)^
     **
     ** [[core URI query parameters]]
     ** The query component of a URI may contain parameters that are interpreted
     ** either by SQLite itself, or by a [VFS | custom VFS implementation].
     ** SQLite and its built-in [VFSes] interpret the
     ** following query parameters:
     **
     ** <ul>
     **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
     **     a VFS object that provides the operating system interface that should
     **     be used to access the database file on disk. ^If this option is set to
     **     an empty string the default VFS object is used. ^Specifying an unknown
     **     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
     **     present, then the VFS specified by the option takes precedence over
     **     the value passed as the fourth parameter to sqlite3_open_v2().
     **
     **   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
     **     "rwc", or "memory". Attempting to set it to any other value is
     **     an error)^.
     **     ^If "ro" is specified, then the database is opened for read-only
     **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
     **     third argument to sqlite3_open_v2(). ^If the mode option is set to
     **     "rw", then the database is opened for read-write (but not create)
     **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
     **     been set. ^Value "rwc" is equivalent to setting both
     **     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
     **     set to "memory" then a pure [in-memory database] that never reads
     **     or writes from disk is used. ^It is an error to specify a value for
     **     the mode parameter that is less restrictive than that specified by
     **     the flags passed in the third parameter to sqlite3_open_v2().
     **
     **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
     **     "private". ^Setting it to "shared" is equivalent to setting the
     **     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
     **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
     **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
     **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
     **     a URI filename, its value overrides any behavior requested by setting
     **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
     **
     **  <li> <b>psow</b>: ^The psow parameter indicates whether or not the
     **     [powersafe overwrite] property does or does not apply to the
     **     storage media on which the database file resides.
     **
     **  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
     **     which if set disables file locking in rollback journal modes.  This
     **     is useful for accessing a database on a filesystem that does not
     **     support locking.  Caution:  Database corruption might result if two
     **     or more processes write to the same database and any one of those
     **     processes uses nolock=1.
     **
     **  <li> <b>immutable</b>: ^The immutable parameter is a boolean query
     **     parameter that indicates that the database file is stored on
     **     read-only media.  ^When immutable is set, SQLite assumes that the
     **     database file cannot be changed, even by a process with higher
     **     privilege, and so the database is opened read-only and all locking
     **     and change detection is disabled.  Caution: Setting the immutable
     **     property on a database file that does in fact change can result
     **     in incorrect query results and/or [SQLITE_CORRUPT] errors.
     **     See also: [SQLITE_IOCAP_IMMUTABLE].
     **
     ** </ul>
     **
     ** ^Specifying an unknown parameter in the query component of a URI is not an
     ** error.  Future versions of SQLite might understand additional query
     ** parameters.  See "[query parameters with special meaning to SQLite]" for
     ** additional information.
     **
     ** [[URI filename examples]] <h3>URI filename examples</h3>
     **
     ** <table border="1" align=center cellpadding=5>
     ** <tr><th> URI filenames <th> Results
     ** <tr><td> file:data.db <td>
     **          Open the file "data.db" in the current directory.
     ** <tr><td> file:/home/fred/data.db<br>
     **          file:///home/fred/data.db <br>
     **          file://localhost/home/fred/data.db <br> <td>
     **          Open the database file "/home/fred/data.db".
     ** <tr><td> file://darkstar/home/fred/data.db <td>
     **          An error. "darkstar" is not a recognized authority.
     ** <tr><td style="white-space:nowrap">
     **          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
     **     <td> Windows only: Open the file "data.db" on fred's desktop on drive
     **          C:. Note that the %20 escaping in this example is not strictly
     **          necessary - space characters can be used literally
     **          in URI filenames.
     ** <tr><td> file:data.db?mode=ro&cache=private <td>
     **          Open file "data.db" in the current directory for read-only access.
     **          Regardless of whether or not shared-cache mode is enabled by
     **          default, use a private cache.
     ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
     **          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
     **          that uses dot-files in place of posix advisory locking.
     ** <tr><td> file:data.db?mode=readonly <td>
     **          An error. "readonly" is not a valid option for the "mode" parameter.
     ** </table>
     **
     ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
     ** query components of a URI. A hexadecimal escape sequence consists of a
     ** percent sign - "%" - followed by exactly two hexadecimal digits
     ** specifying an octet value. ^Before the path or query components of a
     ** URI filename are interpreted, they are encoded using UTF-8 and all
     ** hexadecimal escape sequences replaced by a single byte containing the
     ** corresponding octet. If this process generates an invalid UTF-8 encoding,
     ** the results are undefined.
     **
     ** <b>Note to Windows users:</b>  The encoding used for the filename argument
     ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
     ** codepage is currently defined.  Filenames containing international
     ** characters must be converted to UTF-8 prior to passing them into
     ** sqlite3_open() or sqlite3_open_v2().
     **
     ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
     ** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
     ** features that require the use of temporary files may fail.
     **
     ** See also: [sqlite3_temp_directory]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_open(
                                               const char *filename,   /* Database filename (UTF-8) */
                                               sqlite3 **ppDb          /* OUT: SQLite db handle */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_open16(
                                                 const void *filename,   /* Database filename (UTF-16) */
                                                 sqlite3 **ppDb          /* OUT: SQLite db handle */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_open_v2(
                                                  const char *filename,   /* Database filename (UTF-8) */
                                                  sqlite3 **ppDb,         /* OUT: SQLite db handle */
                                                  int flags,              /* Flags */
                                                  const char *zVfs        /* Name of VFS module to use */
    );
    
    /*
     ** CAPI3REF: Obtain Values For URI Parameters
     **
     ** These are utility routines, useful to VFS implementations, that check
     ** to see if a database file was a URI that contained a specific query
     ** parameter, and if so obtains the value of that query parameter.
     **
     ** If F is the database filename pointer passed into the xOpen() method of
     ** a VFS implementation when the flags parameter to xOpen() has one or
     ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
     ** P is the name of the query parameter, then
     ** sqlite3_uri_parameter(F,P) returns the value of the P
     ** parameter if it exists or a NULL pointer if P does not appear as a
     ** query parameter on F.  If P is a query parameter of F
     ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
     ** a pointer to an empty string.
     **
     ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
     ** parameter and returns true (1) or false (0) according to the value
     ** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
     ** value of query parameter P is one of "yes", "true", or "on" in any
     ** case or if the value begins with a non-zero number.  The
     ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
     ** query parameter P is one of "no", "false", or "off" in any case or
     ** if the value begins with a numeric zero.  If P is not a query
     ** parameter on F or if the value of P is does not match any of the
     ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
     **
     ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
     ** 64-bit signed integer and returns that integer, or D if P does not
     ** exist.  If the value of P is something other than an integer, then
     ** zero is returned.
     **
     ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
     ** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
     ** is not a database file pathname pointer that SQLite passed into the xOpen
     ** VFS method, then the behavior of this routine is undefined and probably
     ** undesirable.
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam);
    SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
    
    
    /*
     ** CAPI3REF: Error Codes And Messages
     ** METHOD: sqlite3
     **
     ** ^If the most recent sqlite3_* API call associated with
     ** [database connection] D failed, then the sqlite3_errcode(D) interface
     ** returns the numeric [result code] or [extended result code] for that
     ** API call.
     ** If the most recent API call was successful,
     ** then the return value from sqlite3_errcode() is undefined.
     ** ^The sqlite3_extended_errcode()
     ** interface is the same except that it always returns the
     ** [extended result code] even when extended result codes are
     ** disabled.
     **
     ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
     ** text that describes the error, as either UTF-8 or UTF-16 respectively.
     ** ^(Memory to hold the error message string is managed internally.
     ** The application does not need to worry about freeing the result.
     ** However, the error string might be overwritten or deallocated by
     ** subsequent calls to other SQLite interface functions.)^
     **
     ** ^The sqlite3_errstr() interface returns the English-language text
     ** that describes the [result code], as UTF-8.
     ** ^(Memory to hold the error message string is managed internally
     ** and must not be freed by the application)^.
     **
     ** When the serialized [threading mode] is in use, it might be the
     ** case that a second error occurs on a separate thread in between
     ** the time of the first error and the call to these interfaces.
     ** When that happens, the second error will be reported since these
     ** interfaces always report the most recent result.  To avoid
     ** this, each thread can obtain exclusive use of the [database connection] D
     ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
     ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
     ** all calls to the interfaces listed here are completed.
     **
     ** If an interface fails with SQLITE_MISUSE, that means the interface
     ** was invoked incorrectly by the application.  In that case, the
     ** error code and message may or may not be set.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db);
    SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db);
    SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*);
    SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int);
    
    /*
     ** CAPI3REF: Prepared Statement Object
     ** KEYWORDS: {prepared statement} {prepared statements}
     **
     ** An instance of this object represents a single SQL statement that
     ** has been compiled into binary form and is ready to be evaluated.
     **
     ** Think of each SQL statement as a separate computer program.  The
     ** original SQL text is source code.  A prepared statement object
     ** is the compiled object code.  All SQL must be converted into a
     ** prepared statement before it can be run.
     **
     ** The life-cycle of a prepared statement object usually goes like this:
     **
     ** <ol>
     ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
     ** <li> Bind values to [parameters] using the sqlite3_bind_*()
     **      interfaces.
     ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
     ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
     **      to step 2.  Do this zero or more times.
     ** <li> Destroy the object using [sqlite3_finalize()].
     ** </ol>
     */
    typedef struct sqlite3_stmt sqlite3_stmt;
    
    /*
     ** CAPI3REF: Run-time Limits
     ** METHOD: sqlite3
     **
     ** ^(This interface allows the size of various constructs to be limited
     ** on a connection by connection basis.  The first parameter is the
     ** [database connection] whose limit is to be set or queried.  The
     ** second parameter is one of the [limit categories] that define a
     ** class of constructs to be size limited.  The third parameter is the
     ** new limit for that construct.)^
     **
     ** ^If the new limit is a negative number, the limit is unchanged.
     ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
     ** [limits | hard upper bound]
     ** set at compile-time by a C preprocessor macro called
     ** [limits | SQLITE_MAX_<i>NAME</i>].
     ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
     ** ^Attempts to increase a limit above its hard upper bound are
     ** silently truncated to the hard upper bound.
     **
     ** ^Regardless of whether or not the limit was changed, the
     ** [sqlite3_limit()] interface returns the prior value of the limit.
     ** ^Hence, to find the current value of a limit without changing it,
     ** simply invoke this interface with the third parameter set to -1.
     **
     ** Run-time limits are intended for use in applications that manage
     ** both their own internal database and also databases that are controlled
     ** by untrusted external sources.  An example application might be a
     ** web browser that has its own databases for storing history and
     ** separate databases controlled by JavaScript applications downloaded
     ** off the Internet.  The internal databases can be given the
     ** large, default limits.  Databases managed by external sources can
     ** be given much smaller limits designed to prevent a denial of service
     ** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
     ** interface to further control untrusted SQL.  The size of the database
     ** created by an untrusted script can be contained using the
     ** [max_page_count] [PRAGMA].
     **
     ** New run-time limit categories may be added in future releases.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal);
    
    /*
     ** CAPI3REF: Run-Time Limit Categories
     ** KEYWORDS: {limit category} {*limit categories}
     **
     ** These constants define various performance limits
     ** that can be lowered at run-time using [sqlite3_limit()].
     ** The synopsis of the meanings of the various limits is shown below.
     ** Additional information is available at [limits | Limits in SQLite].
     **
     ** <dl>
     ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
     ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
     **
     ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
     ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
     **
     ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
     ** <dd>The maximum number of columns in a table definition or in the
     ** result set of a [SELECT] or the maximum number of columns in an index
     ** or in an ORDER BY or GROUP BY clause.</dd>)^
     **
     ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
     ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
     **
     ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
     ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
     **
     ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
     ** <dd>The maximum number of instructions in a virtual machine program
     ** used to implement an SQL statement.  This limit is not currently
     ** enforced, though that might be added in some future release of
     ** SQLite.</dd>)^
     **
     ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
     ** <dd>The maximum number of arguments on a function.</dd>)^
     **
     ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
     ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
     **
     ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
     ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
     ** <dd>The maximum length of the pattern argument to the [LIKE] or
     ** [GLOB] operators.</dd>)^
     **
     ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
     ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
     ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
     **
     ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
     ** <dd>The maximum depth of recursion for triggers.</dd>)^
     **
     ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
     ** <dd>The maximum number of auxiliary worker threads that a single
     ** [prepared statement] may start.</dd>)^
     ** </dl>
     */
#define SQLITE_LIMIT_LENGTH                    0
#define SQLITE_LIMIT_SQL_LENGTH                1
#define SQLITE_LIMIT_COLUMN                    2
#define SQLITE_LIMIT_EXPR_DEPTH                3
#define SQLITE_LIMIT_COMPOUND_SELECT           4
#define SQLITE_LIMIT_VDBE_OP                   5
#define SQLITE_LIMIT_FUNCTION_ARG              6
#define SQLITE_LIMIT_ATTACHED                  7
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
#define SQLITE_LIMIT_VARIABLE_NUMBER           9
#define SQLITE_LIMIT_TRIGGER_DEPTH            10
#define SQLITE_LIMIT_WORKER_THREADS           11
    
    /*
     ** CAPI3REF: Compiling An SQL Statement
     ** KEYWORDS: {SQL statement compiler}
     ** METHOD: sqlite3
     ** CONSTRUCTOR: sqlite3_stmt
     **
     ** To execute an SQL query, it must first be compiled into a byte-code
     ** program using one of these routines.
     **
     ** The first argument, "db", is a [database connection] obtained from a
     ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
     ** [sqlite3_open16()].  The database connection must not have been closed.
     **
     ** The second argument, "zSql", is the statement to be compiled, encoded
     ** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
     ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
     ** use UTF-16.
     **
     ** ^If the nByte argument is negative, then zSql is read up to the
     ** first zero terminator. ^If nByte is positive, then it is the
     ** number of bytes read from zSql.  ^If nByte is zero, then no prepared
     ** statement is generated.
     ** If the caller knows that the supplied string is nul-terminated, then
     ** there is a small performance advantage to passing an nByte parameter that
     ** is the number of bytes in the input string <i>including</i>
     ** the nul-terminator.
     **
     ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
     ** past the end of the first SQL statement in zSql.  These routines only
     ** compile the first statement in zSql, so *pzTail is left pointing to
     ** what remains uncompiled.
     **
     ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
     ** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
     ** to NULL.  ^If the input text contains no SQL (if the input is an empty
     ** string or a comment) then *ppStmt is set to NULL.
     ** The calling procedure is responsible for deleting the compiled
     ** SQL statement using [sqlite3_finalize()] after it has finished with it.
     ** ppStmt may not be NULL.
     **
     ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
     ** otherwise an [error code] is returned.
     **
     ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
     ** recommended for all new programs. The two older interfaces are retained
     ** for backwards compatibility, but their use is discouraged.
     ** ^In the "v2" interfaces, the prepared statement
     ** that is returned (the [sqlite3_stmt] object) contains a copy of the
     ** original SQL text. This causes the [sqlite3_step()] interface to
     ** behave differently in three ways:
     **
     ** <ol>
     ** <li>
     ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
     ** always used to do, [sqlite3_step()] will automatically recompile the SQL
     ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
     ** retries will occur before sqlite3_step() gives up and returns an error.
     ** </li>
     **
     ** <li>
     ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
     ** [error codes] or [extended error codes].  ^The legacy behavior was that
     ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
     ** and the application would have to make a second call to [sqlite3_reset()]
     ** in order to find the underlying cause of the problem. With the "v2" prepare
     ** interfaces, the underlying reason for the error is returned immediately.
     ** </li>
     **
     ** <li>
     ** ^If the specific value bound to [parameter | host parameter] in the
     ** WHERE clause might influence the choice of query plan for a statement,
     ** then the statement will be automatically recompiled, as if there had been
     ** a schema change, on the first  [sqlite3_step()] call following any change
     ** to the [sqlite3_bind_text | bindings] of that [parameter].
     ** ^The specific value of WHERE-clause [parameter] might influence the
     ** choice of query plan if the parameter is the left-hand side of a [LIKE]
     ** or [GLOB] operator or if the parameter is compared to an indexed column
     ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
     ** </li>
     ** </ol>
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_prepare(
                                                  sqlite3 *db,            /* Database handle */
                                                  const char *zSql,       /* SQL statement, UTF-8 encoded */
                                                  int nByte,              /* Maximum length of zSql in bytes. */
                                                  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
                                                  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2(
                                                     sqlite3 *db,            /* Database handle */
                                                     const char *zSql,       /* SQL statement, UTF-8 encoded */
                                                     int nByte,              /* Maximum length of zSql in bytes. */
                                                     sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
                                                     const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_prepare16(
                                                    sqlite3 *db,            /* Database handle */
                                                    const void *zSql,       /* SQL statement, UTF-16 encoded */
                                                    int nByte,              /* Maximum length of zSql in bytes. */
                                                    sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
                                                    const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2(
                                                       sqlite3 *db,            /* Database handle */
                                                       const void *zSql,       /* SQL statement, UTF-16 encoded */
                                                       int nByte,              /* Maximum length of zSql in bytes. */
                                                       sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
                                                       const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    
    /*
     ** CAPI3REF: Retrieving Statement SQL
     ** METHOD: sqlite3_stmt
     **
     ** ^This interface can be used to retrieve a saved copy of the original
     ** SQL text used to create a [prepared statement] if that statement was
     ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Determine If An SQL Statement Writes The Database
     ** METHOD: sqlite3_stmt
     **
     ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
     ** and only if the [prepared statement] X makes no direct changes to
     ** the content of the database file.
     **
     ** Note that [application-defined SQL functions] or
     ** [virtual tables] might change the database indirectly as a side effect.
     ** ^(For example, if an application defines a function "eval()" that
     ** calls [sqlite3_exec()], then the following SQL statement would
     ** change the database file through side-effects:
     **
     ** <blockquote><pre>
     **    SELECT eval('DELETE FROM t1') FROM t2;
     ** </pre></blockquote>
     **
     ** But because the [SELECT] statement does not change the database file
     ** directly, sqlite3_stmt_readonly() would still return true.)^
     **
     ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
     ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
     ** since the statements themselves do not actually modify the database but
     ** rather they control the timing of when other statements modify the
     ** database.  ^The [ATTACH] and [DETACH] statements also cause
     ** sqlite3_stmt_readonly() to return true since, while those statements
     ** change the configuration of a database connection, they do not make
     ** changes to the content of the database files on disk.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
     ** METHOD: sqlite3_stmt
     **
     ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
     ** [prepared statement] S has been stepped at least once using
     ** [sqlite3_step(S)] but has neither run to completion (returned
     ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
     ** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
     ** interface returns false if S is a NULL pointer.  If S is not a
     ** NULL pointer and is not a pointer to a valid [prepared statement]
     ** object, then the behavior is undefined and probably undesirable.
     **
     ** This interface can be used in combination [sqlite3_next_stmt()]
     ** to locate all prepared statements associated with a database
     ** connection that are in need of being reset.  This can be used,
     ** for example, in diagnostic routines to search for prepared
     ** statements that are holding a transaction open.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*);
    
    /*
     ** CAPI3REF: Dynamically Typed Value Object
     ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
     **
     ** SQLite uses the sqlite3_value object to represent all values
     ** that can be stored in a database table. SQLite uses dynamic typing
     ** for the values it stores.  ^Values stored in sqlite3_value objects
     ** can be integers, floating point values, strings, BLOBs, or NULL.
     **
     ** An sqlite3_value object may be either "protected" or "unprotected".
     ** Some interfaces require a protected sqlite3_value.  Other interfaces
     ** will accept either a protected or an unprotected sqlite3_value.
     ** Every interface that accepts sqlite3_value arguments specifies
     ** whether or not it requires a protected sqlite3_value.  The
     ** [sqlite3_value_dup()] interface can be used to construct a new
     ** protected sqlite3_value from an unprotected sqlite3_value.
     **
     ** The terms "protected" and "unprotected" refer to whether or not
     ** a mutex is held.  An internal mutex is held for a protected
     ** sqlite3_value object but no mutex is held for an unprotected
     ** sqlite3_value object.  If SQLite is compiled to be single-threaded
     ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
     ** or if SQLite is run in one of reduced mutex modes
     ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
     ** then there is no distinction between protected and unprotected
     ** sqlite3_value objects and they can be used interchangeably.  However,
     ** for maximum code portability it is recommended that applications
     ** still make the distinction between protected and unprotected
     ** sqlite3_value objects even when not strictly required.
     **
     ** ^The sqlite3_value objects that are passed as parameters into the
     ** implementation of [application-defined SQL functions] are protected.
     ** ^The sqlite3_value object returned by
     ** [sqlite3_column_value()] is unprotected.
     ** Unprotected sqlite3_value objects may only be used with
     ** [sqlite3_result_value()] and [sqlite3_bind_value()].
     ** The [sqlite3_value_blob | sqlite3_value_type()] family of
     ** interfaces require protected sqlite3_value objects.
     */
    typedef struct Mem sqlite3_value;
    
    /*
     ** CAPI3REF: SQL Function Context Object
     **
     ** The context in which an SQL function executes is stored in an
     ** sqlite3_context object.  ^A pointer to an sqlite3_context object
     ** is always first parameter to [application-defined SQL functions].
     ** The application-defined SQL function implementation will pass this
     ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
     ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
     ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
     ** and/or [sqlite3_set_auxdata()].
     */
    typedef struct sqlite3_context sqlite3_context;
    
    /*
     ** CAPI3REF: Binding Values To Prepared Statements
     ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
     ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
     ** METHOD: sqlite3_stmt
     **
     ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
     ** literals may be replaced by a [parameter] that matches one of following
     ** templates:
     **
     ** <ul>
     ** <li>  ?
     ** <li>  ?NNN
     ** <li>  :VVV
     ** <li>  @VVV
     ** <li>  $VVV
     ** </ul>
     **
     ** In the templates above, NNN represents an integer literal,
     ** and VVV represents an alphanumeric identifier.)^  ^The values of these
     ** parameters (also called "host parameter names" or "SQL parameters")
     ** can be set using the sqlite3_bind_*() routines defined here.
     **
     ** ^The first argument to the sqlite3_bind_*() routines is always
     ** a pointer to the [sqlite3_stmt] object returned from
     ** [sqlite3_prepare_v2()] or its variants.
     **
     ** ^The second argument is the index of the SQL parameter to be set.
     ** ^The leftmost SQL parameter has an index of 1.  ^When the same named
     ** SQL parameter is used more than once, second and subsequent
     ** occurrences have the same index as the first occurrence.
     ** ^The index for named parameters can be looked up using the
     ** [sqlite3_bind_parameter_index()] API if desired.  ^The index
     ** for "?NNN" parameters is the value of NNN.
     ** ^The NNN value must be between 1 and the [sqlite3_limit()]
     ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
     **
     ** ^The third argument is the value to bind to the parameter.
     ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
     ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
     ** is ignored and the end result is the same as sqlite3_bind_null().
     **
     ** ^(In those routines that have a fourth argument, its value is the
     ** number of bytes in the parameter.  To be clear: the value is the
     ** number of <u>bytes</u> in the value, not the number of characters.)^
     ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
     ** is negative, then the length of the string is
     ** the number of bytes up to the first zero terminator.
     ** If the fourth parameter to sqlite3_bind_blob() is negative, then
     ** the behavior is undefined.
     ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
     ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
     ** that parameter must be the byte offset
     ** where the NUL terminator would occur assuming the string were NUL
     ** terminated.  If any NUL characters occur at byte offsets less than
     ** the value of the fourth parameter then the resulting string value will
     ** contain embedded NULs.  The result of expressions involving strings
     ** with embedded NULs is undefined.
     **
     ** ^The fifth argument to the BLOB and string binding interfaces
     ** is a destructor used to dispose of the BLOB or
     ** string after SQLite has finished with it.  ^The destructor is called
     ** to dispose of the BLOB or string even if the call to bind API fails.
     ** ^If the fifth argument is
     ** the special value [SQLITE_STATIC], then SQLite assumes that the
     ** information is in static, unmanaged space and does not need to be freed.
     ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
     ** SQLite makes its own private copy of the data immediately, before
     ** the sqlite3_bind_*() routine returns.
     **
     ** ^The sixth argument to sqlite3_bind_text64() must be one of
     ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
     ** to specify the encoding of the text in the third parameter.  If
     ** the sixth argument to sqlite3_bind_text64() is not one of the
     ** allowed values shown above, or if the text encoding is different
     ** from the encoding specified by the sixth parameter, then the behavior
     ** is undefined.
     **
     ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
     ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
     ** (just an integer to hold its size) while it is being processed.
     ** Zeroblobs are intended to serve as placeholders for BLOBs whose
     ** content is later written using
     ** [sqlite3_blob_open | incremental BLOB I/O] routines.
     ** ^A negative value for the zeroblob results in a zero-length BLOB.
     **
     ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
     ** for the [prepared statement] or with a prepared statement for which
     ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
     ** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
     ** routine is passed a [prepared statement] that has been finalized, the
     ** result is undefined and probably harmful.
     **
     ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
     ** ^Unbound parameters are interpreted as NULL.
     **
     ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
     ** [error code] if anything goes wrong.
     ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
     ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
     ** [SQLITE_MAX_LENGTH].
     ** ^[SQLITE_RANGE] is returned if the parameter
     ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
     **
     ** See also: [sqlite3_bind_parameter_count()],
     ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
                                                      void(*)(void*));
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
                                                      void(*)(void*), unsigned char encoding);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
    
    /*
     ** CAPI3REF: Number Of SQL Parameters
     ** METHOD: sqlite3_stmt
     **
     ** ^This routine can be used to find the number of [SQL parameters]
     ** in a [prepared statement].  SQL parameters are tokens of the
     ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
     ** placeholders for values that are [sqlite3_bind_blob | bound]
     ** to the parameters at a later time.
     **
     ** ^(This routine actually returns the index of the largest (rightmost)
     ** parameter. For all forms except ?NNN, this will correspond to the
     ** number of unique parameters.  If parameters of the ?NNN form are used,
     ** there may be gaps in the list.)^
     **
     ** See also: [sqlite3_bind_blob|sqlite3_bind()],
     ** [sqlite3_bind_parameter_name()], and
     ** [sqlite3_bind_parameter_index()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*);
    
    /*
     ** CAPI3REF: Name Of A Host Parameter
     ** METHOD: sqlite3_stmt
     **
     ** ^The sqlite3_bind_parameter_name(P,N) interface returns
     ** the name of the N-th [SQL parameter] in the [prepared statement] P.
     ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
     ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
     ** respectively.
     ** In other words, the initial ":" or "$" or "@" or "?"
     ** is included as part of the name.)^
     ** ^Parameters of the form "?" without a following integer have no name
     ** and are referred to as "nameless" or "anonymous parameters".
     **
     ** ^The first host parameter has an index of 1, not 0.
     **
     ** ^If the value N is out of range or if the N-th parameter is
     ** nameless, then NULL is returned.  ^The returned string is
     ** always in UTF-8 encoding even if the named parameter was
     ** originally specified as UTF-16 in [sqlite3_prepare16()] or
     ** [sqlite3_prepare16_v2()].
     **
     ** See also: [sqlite3_bind_blob|sqlite3_bind()],
     ** [sqlite3_bind_parameter_count()], and
     ** [sqlite3_bind_parameter_index()].
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int);
    
    /*
     ** CAPI3REF: Index Of A Parameter With A Given Name
     ** METHOD: sqlite3_stmt
     **
     ** ^Return the index of an SQL parameter given its name.  ^The
     ** index value returned is suitable for use as the second
     ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
     ** is returned if no matching parameter is found.  ^The parameter
     ** name must be given in UTF-8 even if the original statement
     ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
     **
     ** See also: [sqlite3_bind_blob|sqlite3_bind()],
     ** [sqlite3_bind_parameter_count()], and
     ** [sqlite3_bind_parameter_name()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
    
    /*
     ** CAPI3REF: Reset All Bindings On A Prepared Statement
     ** METHOD: sqlite3_stmt
     **
     ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
     ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
     ** ^Use this routine to reset all host parameters to NULL.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*);
    
    /*
     ** CAPI3REF: Number Of Columns In A Result Set
     ** METHOD: sqlite3_stmt
     **
     ** ^Return the number of columns in the result set returned by the
     ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
     ** statement that does not return data (for example an [UPDATE]).
     **
     ** See also: [sqlite3_data_count()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Column Names In A Result Set
     ** METHOD: sqlite3_stmt
     **
     ** ^These routines return the name assigned to a particular column
     ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
     ** interface returns a pointer to a zero-terminated UTF-8 string
     ** and sqlite3_column_name16() returns a pointer to a zero-terminated
     ** UTF-16 string.  ^The first parameter is the [prepared statement]
     ** that implements the [SELECT] statement. ^The second parameter is the
     ** column number.  ^The leftmost column is number 0.
     **
     ** ^The returned string pointer is valid until either the [prepared statement]
     ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
     ** reprepared by the first call to [sqlite3_step()] for a particular run
     ** or until the next call to
     ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
     **
     ** ^If sqlite3_malloc() fails during the processing of either routine
     ** (for example during a conversion from UTF-8 to UTF-16) then a
     ** NULL pointer is returned.
     **
     ** ^The name of a result column is the value of the "AS" clause for
     ** that column, if there is an AS clause.  If there is no AS clause
     ** then the name of the column is unspecified and may change from
     ** one release of SQLite to the next.
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N);
    
    /*
     ** CAPI3REF: Source Of Data In A Query Result
     ** METHOD: sqlite3_stmt
     **
     ** ^These routines provide a means to determine the database, table, and
     ** table column that is the origin of a particular result column in
     ** [SELECT] statement.
     ** ^The name of the database or table or column can be returned as
     ** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
     ** the database name, the _table_ routines return the table name, and
     ** the origin_ routines return the column name.
     ** ^The returned string is valid until the [prepared statement] is destroyed
     ** using [sqlite3_finalize()] or until the statement is automatically
     ** reprepared by the first call to [sqlite3_step()] for a particular run
     ** or until the same information is requested
     ** again in a different encoding.
     **
     ** ^The names returned are the original un-aliased names of the
     ** database, table, and column.
     **
     ** ^The first argument to these interfaces is a [prepared statement].
     ** ^These functions return information about the Nth result column returned by
     ** the statement, where N is the second function argument.
     ** ^The left-most column is column 0 for these routines.
     **
     ** ^If the Nth column returned by the statement is an expression or
     ** subquery and is not a column value, then all of these functions return
     ** NULL.  ^These routine might also return NULL if a memory allocation error
     ** occurs.  ^Otherwise, they return the name of the attached database, table,
     ** or column that query result column was extracted from.
     **
     ** ^As with all other SQLite APIs, those whose names end with "16" return
     ** UTF-16 encoded strings and the other functions return UTF-8.
     **
     ** ^These APIs are only available if the library was compiled with the
     ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
     **
     ** If two or more threads call one or more of these routines against the same
     ** prepared statement and column at the same time then the results are
     ** undefined.
     **
     ** If two or more threads call one or more
     ** [sqlite3_column_database_name | column metadata interfaces]
     ** for the same [prepared statement] and result column
     ** at the same time then the results are undefined.
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int);
    SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int);
    SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int);
    
    /*
     ** CAPI3REF: Declared Datatype Of A Query Result
     ** METHOD: sqlite3_stmt
     **
     ** ^(The first parameter is a [prepared statement].
     ** If this statement is a [SELECT] statement and the Nth column of the
     ** returned result set of that [SELECT] is a table column (not an
     ** expression or subquery) then the declared type of the table
     ** column is returned.)^  ^If the Nth column of the result set is an
     ** expression or subquery, then a NULL pointer is returned.
     ** ^The returned string is always UTF-8 encoded.
     **
     ** ^(For example, given the database schema:
     **
     ** CREATE TABLE t1(c1 VARIANT);
     **
     ** and the following statement to be compiled:
     **
     ** SELECT c1 + 1, c1 FROM t1;
     **
     ** this routine would return the string "VARIANT" for the second result
     ** column (i==1), and a NULL pointer for the first result column (i==0).)^
     **
     ** ^SQLite uses dynamic run-time typing.  ^So just because a column
     ** is declared to contain a particular type does not mean that the
     ** data stored in that column is of the declared type.  SQLite is
     ** strongly typed, but the typing is dynamic not static.  ^Type
     ** is associated with individual values, not with the containers
     ** used to hold those values.
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int);
    
    /*
     ** CAPI3REF: Evaluate An SQL Statement
     ** METHOD: sqlite3_stmt
     **
     ** After a [prepared statement] has been prepared using either
     ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
     ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
     ** must be called one or more times to evaluate the statement.
     **
     ** The details of the behavior of the sqlite3_step() interface depend
     ** on whether the statement was prepared using the newer "v2" interface
     ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
     ** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
     ** new "v2" interface is recommended for new applications but the legacy
     ** interface will continue to be supported.
     **
     ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
     ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
     ** ^With the "v2" interface, any of the other [result codes] or
     ** [extended result codes] might be returned as well.
     **
     ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
     ** database locks it needs to do its job.  ^If the statement is a [COMMIT]
     ** or occurs outside of an explicit transaction, then you can retry the
     ** statement.  If the statement is not a [COMMIT] and occurs within an
     ** explicit transaction then you should rollback the transaction before
     ** continuing.
     **
     ** ^[SQLITE_DONE] means that the statement has finished executing
     ** successfully.  sqlite3_step() should not be called again on this virtual
     ** machine without first calling [sqlite3_reset()] to reset the virtual
     ** machine back to its initial state.
     **
     ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
     ** is returned each time a new row of data is ready for processing by the
     ** caller. The values may be accessed using the [column access functions].
     ** sqlite3_step() is called again to retrieve the next row of data.
     **
     ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
     ** violation) has occurred.  sqlite3_step() should not be called again on
     ** the VM. More information may be found by calling [sqlite3_errmsg()].
     ** ^With the legacy interface, a more specific error code (for example,
     ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
     ** can be obtained by calling [sqlite3_reset()] on the
     ** [prepared statement].  ^In the "v2" interface,
     ** the more specific error code is returned directly by sqlite3_step().
     **
     ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
     ** Perhaps it was called on a [prepared statement] that has
     ** already been [sqlite3_finalize | finalized] or on one that had
     ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
     ** be the case that the same database connection is being used by two or
     ** more threads at the same moment in time.
     **
     ** For all versions of SQLite up to and including 3.6.23.1, a call to
     ** [sqlite3_reset()] was required after sqlite3_step() returned anything
     ** other than [SQLITE_ROW] before any subsequent invocation of
     ** sqlite3_step().  Failure to reset the prepared statement using
     ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
     ** sqlite3_step().  But after version 3.6.23.1, sqlite3_step() began
     ** calling [sqlite3_reset()] automatically in this circumstance rather
     ** than returning [SQLITE_MISUSE].  This is not considered a compatibility
     ** break because any application that ever receives an SQLITE_MISUSE error
     ** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
     ** can be used to restore the legacy behavior.
     **
     ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
     ** API always returns a generic error code, [SQLITE_ERROR], following any
     ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
     ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
     ** specific [error codes] that better describes the error.
     ** We admit that this is a goofy design.  The problem has been fixed
     ** with the "v2" interface.  If you prepare all of your SQL statements
     ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
     ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
     ** then the more specific [error codes] are returned directly
     ** by sqlite3_step().  The use of the "v2" interface is recommended.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*);
    
    /*
     ** CAPI3REF: Number of columns in a result set
     ** METHOD: sqlite3_stmt
     **
     ** ^The sqlite3_data_count(P) interface returns the number of columns in the
     ** current row of the result set of [prepared statement] P.
     ** ^If prepared statement P does not have results ready to return
     ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
     ** interfaces) then sqlite3_data_count(P) returns 0.
     ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
     ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
     ** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
     ** will return non-zero if previous call to [sqlite3_step](P) returned
     ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
     ** where it always returns zero since each step of that multi-step
     ** pragma returns 0 columns of data.
     **
     ** See also: [sqlite3_column_count()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Fundamental Datatypes
     ** KEYWORDS: SQLITE_TEXT
     **
     ** ^(Every value in SQLite has one of five fundamental datatypes:
     **
     ** <ul>
     ** <li> 64-bit signed integer
     ** <li> 64-bit IEEE floating point number
     ** <li> string
     ** <li> BLOB
     ** <li> NULL
     ** </ul>)^
     **
     ** These constants are codes for each of those types.
     **
     ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
     ** for a completely different meaning.  Software that links against both
     ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
     ** SQLITE_TEXT.
     */
#define SQLITE_INTEGER  1
#define SQLITE_FLOAT    2
#define SQLITE_BLOB     4
#define SQLITE_NULL     5
#ifdef SQLITE_TEXT
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT     3
#endif
#define SQLITE3_TEXT     3
    
    /*
     ** CAPI3REF: Result Values From A Query
     ** KEYWORDS: {column access functions}
     ** METHOD: sqlite3_stmt
     **
     ** ^These routines return information about a single column of the current
     ** result row of a query.  ^In every case the first argument is a pointer
     ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
     ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
     ** and the second argument is the index of the column for which information
     ** should be returned. ^The leftmost column of the result set has the index 0.
     ** ^The number of columns in the result can be determined using
     ** [sqlite3_column_count()].
     **
     ** If the SQL statement does not currently point to a valid row, or if the
     ** column index is out of range, the result is undefined.
     ** These routines may only be called when the most recent call to
     ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
     ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
     ** If any of these routines are called after [sqlite3_reset()] or
     ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
     ** something other than [SQLITE_ROW], the results are undefined.
     ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
     ** are called from a different thread while any of these routines
     ** are pending, then the results are undefined.
     **
     ** ^The sqlite3_column_type() routine returns the
     ** [SQLITE_INTEGER | datatype code] for the initial data type
     ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
     ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
     ** returned by sqlite3_column_type() is only meaningful if no type
     ** conversions have occurred as described below.  After a type conversion,
     ** the value returned by sqlite3_column_type() is undefined.  Future
     ** versions of SQLite may change the behavior of sqlite3_column_type()
     ** following a type conversion.
     **
     ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
     ** routine returns the number of bytes in that BLOB or string.
     ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
     ** the string to UTF-8 and then returns the number of bytes.
     ** ^If the result is a numeric value then sqlite3_column_bytes() uses
     ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
     ** the number of bytes in that string.
     ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
     **
     ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
     ** routine returns the number of bytes in that BLOB or string.
     ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
     ** the string to UTF-16 and then returns the number of bytes.
     ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
     ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
     ** the number of bytes in that string.
     ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
     **
     ** ^The values returned by [sqlite3_column_bytes()] and
     ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
     ** of the string.  ^For clarity: the values returned by
     ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
     ** bytes in the string, not the number of characters.
     **
     ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
     ** even empty strings, are always zero-terminated.  ^The return
     ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
     **
     ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
     ** [unprotected sqlite3_value] object.  In a multithreaded environment,
     ** an unprotected sqlite3_value object may only be used safely with
     ** [sqlite3_bind_value()] and [sqlite3_result_value()].
     ** If the [unprotected sqlite3_value] object returned by
     ** [sqlite3_column_value()] is used in any other way, including calls
     ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
     ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
     **
     ** These routines attempt to convert the value where appropriate.  ^For
     ** example, if the internal representation is FLOAT and a text result
     ** is requested, [sqlite3_snprintf()] is used internally to perform the
     ** conversion automatically.  ^(The following table details the conversions
     ** that are applied:
     **
     ** <blockquote>
     ** <table border="1">
     ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
     **
     ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
     ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
     ** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
     ** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
     ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
     ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
     ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
     ** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
     ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
     ** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
     ** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
     ** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
     ** <tr><td>  TEXT    <td>   BLOB    <td> No change
     ** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
     ** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
     ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
     ** </table>
     ** </blockquote>)^
     **
     ** Note that when type conversions occur, pointers returned by prior
     ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
     ** sqlite3_column_text16() may be invalidated.
     ** Type conversions and pointer invalidations might occur
     ** in the following cases:
     **
     ** <ul>
     ** <li> The initial content is a BLOB and sqlite3_column_text() or
     **      sqlite3_column_text16() is called.  A zero-terminator might
     **      need to be added to the string.</li>
     ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
     **      sqlite3_column_text16() is called.  The content must be converted
     **      to UTF-16.</li>
     ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
     **      sqlite3_column_text() is called.  The content must be converted
     **      to UTF-8.</li>
     ** </ul>
     **
     ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
     ** not invalidate a prior pointer, though of course the content of the buffer
     ** that the prior pointer references will have been modified.  Other kinds
     ** of conversion are done in place when it is possible, but sometimes they
     ** are not possible and in those cases prior pointers are invalidated.
     **
     ** The safest policy is to invoke these routines
     ** in one of the following ways:
     **
     ** <ul>
     **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
     **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
     **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
     ** </ul>
     **
     ** In other words, you should call sqlite3_column_text(),
     ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
     ** into the desired format, then invoke sqlite3_column_bytes() or
     ** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
     ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
     ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
     ** with calls to sqlite3_column_bytes().
     **
     ** ^The pointers returned are valid until a type conversion occurs as
     ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
     ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
     ** and BLOBs is freed automatically.  Do <em>not</em> pass the pointers returned
     ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
     ** [sqlite3_free()].
     **
     ** ^(If a memory allocation error occurs during the evaluation of any
     ** of these routines, a default value is returned.  The default value
     ** is either the integer 0, the floating point number 0.0, or a NULL
     ** pointer.  Subsequent calls to [sqlite3_errcode()] will return
     ** [SQLITE_NOMEM].)^
     */
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol);
    SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol);
    SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
    SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol);
    SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol);
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol);
    SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol);
    SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol);
    SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol);
    
    /*
     ** CAPI3REF: Destroy A Prepared Statement Object
     ** DESTRUCTOR: sqlite3_stmt
     **
     ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
     ** ^If the most recent evaluation of the statement encountered no errors
     ** or if the statement is never been evaluated, then sqlite3_finalize() returns
     ** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
     ** sqlite3_finalize(S) returns the appropriate [error code] or
     ** [extended error code].
     **
     ** ^The sqlite3_finalize(S) routine can be called at any point during
     ** the life cycle of [prepared statement] S:
     ** before statement S is ever evaluated, after
     ** one or more calls to [sqlite3_reset()], or after any call
     ** to [sqlite3_step()] regardless of whether or not the statement has
     ** completed execution.
     **
     ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
     **
     ** The application must finalize every [prepared statement] in order to avoid
     ** resource leaks.  It is a grievous error for the application to try to use
     ** a prepared statement after it has been finalized.  Any use of a prepared
     ** statement after it has been finalized can result in undefined and
     ** undesirable behavior such as segfaults and heap corruption.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Reset A Prepared Statement Object
     ** METHOD: sqlite3_stmt
     **
     ** The sqlite3_reset() function is called to reset a [prepared statement]
     ** object back to its initial state, ready to be re-executed.
     ** ^Any SQL statement variables that had values bound to them using
     ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
     ** Use [sqlite3_clear_bindings()] to reset the bindings.
     **
     ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
     ** back to the beginning of its program.
     **
     ** ^If the most recent call to [sqlite3_step(S)] for the
     ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
     ** or if [sqlite3_step(S)] has never before been called on S,
     ** then [sqlite3_reset(S)] returns [SQLITE_OK].
     **
     ** ^If the most recent call to [sqlite3_step(S)] for the
     ** [prepared statement] S indicated an error, then
     ** [sqlite3_reset(S)] returns an appropriate [error code].
     **
     ** ^The [sqlite3_reset(S)] interface does not change the values
     ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Create Or Redefine SQL Functions
     ** KEYWORDS: {function creation routines}
     ** KEYWORDS: {application-defined SQL function}
     ** KEYWORDS: {application-defined SQL functions}
     ** METHOD: sqlite3
     **
     ** ^These functions (collectively known as "function creation routines")
     ** are used to add SQL functions or aggregates or to redefine the behavior
     ** of existing SQL functions or aggregates.  The only differences between
     ** these routines are the text encoding expected for
     ** the second parameter (the name of the function being created)
     ** and the presence or absence of a destructor callback for
     ** the application data pointer.
     **
     ** ^The first parameter is the [database connection] to which the SQL
     ** function is to be added.  ^If an application uses more than one database
     ** connection then application-defined SQL functions must be added
     ** to each database connection separately.
     **
     ** ^The second parameter is the name of the SQL function to be created or
     ** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
     ** representation, exclusive of the zero-terminator.  ^Note that the name
     ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
     ** ^Any attempt to create a function with a longer name
     ** will result in [SQLITE_MISUSE] being returned.
     **
     ** ^The third parameter (nArg)
     ** is the number of arguments that the SQL function or
     ** aggregate takes. ^If this parameter is -1, then the SQL function or
     ** aggregate may take any number of arguments between 0 and the limit
     ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
     ** parameter is less than -1 or greater than 127 then the behavior is
     ** undefined.
     **
     ** ^The fourth parameter, eTextRep, specifies what
     ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
     ** its parameters.  The application should set this parameter to
     ** [SQLITE_UTF16LE] if the function implementation invokes
     ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
     ** implementation invokes [sqlite3_value_text16be()] on an input, or
     ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
     ** otherwise.  ^The same SQL function may be registered multiple times using
     ** different preferred text encodings, with different implementations for
     ** each encoding.
     ** ^When multiple implementations of the same function are available, SQLite
     ** will pick the one that involves the least amount of data conversion.
     **
     ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
     ** to signal that the function will always return the same result given
     ** the same inputs within a single SQL statement.  Most SQL functions are
     ** deterministic.  The built-in [random()] SQL function is an example of a
     ** function that is not deterministic.  The SQLite query planner is able to
     ** perform additional optimizations on deterministic functions, so use
     ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
     **
     ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
     ** function can gain access to this pointer using [sqlite3_user_data()].)^
     **
     ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
     ** pointers to C-language functions that implement the SQL function or
     ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
     ** callback only; NULL pointers must be passed as the xStep and xFinal
     ** parameters. ^An aggregate SQL function requires an implementation of xStep
     ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
     ** SQL function or aggregate, pass NULL pointers for all three function
     ** callbacks.
     **
     ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
     ** then it is destructor for the application data pointer.
     ** The destructor is invoked when the function is deleted, either by being
     ** overloaded or when the database connection closes.)^
     ** ^The destructor is also invoked if the call to
     ** sqlite3_create_function_v2() fails.
     ** ^When the destructor callback of the tenth parameter is invoked, it
     ** is passed a single argument which is a copy of the application data
     ** pointer which was the fifth parameter to sqlite3_create_function_v2().
     **
     ** ^It is permitted to register multiple implementations of the same
     ** functions with the same name but with either differing numbers of
     ** arguments or differing preferred text encodings.  ^SQLite will use
     ** the implementation that most closely matches the way in which the
     ** SQL function is used.  ^A function implementation with a non-negative
     ** nArg parameter is a better match than a function implementation with
     ** a negative nArg.  ^A function where the preferred text encoding
     ** matches the database encoding is a better
     ** match than a function where the encoding is different.
     ** ^A function where the encoding difference is between UTF16le and UTF16be
     ** is a closer match than a function where the encoding difference is
     ** between UTF8 and UTF16.
     **
     ** ^Built-in functions may be overloaded by new application-defined functions.
     **
     ** ^An application-defined function is permitted to call other
     ** SQLite interfaces.  However, such calls must not
     ** close the database connection nor finalize or reset the prepared
     ** statement in which the function is running.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
                                                          sqlite3 *db,
                                                          const char *zFunctionName,
                                                          int nArg,
                                                          int eTextRep,
                                                          void *pApp,
                                                          void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
                                                          void (*xStep)(sqlite3_context*,int,sqlite3_value**),
                                                          void (*xFinal)(sqlite3_context*)
                                                          );
    SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
                                                            sqlite3 *db,
                                                            const void *zFunctionName,
                                                            int nArg,
                                                            int eTextRep,
                                                            void *pApp,
                                                            void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
                                                            void (*xStep)(sqlite3_context*,int,sqlite3_value**),
                                                            void (*xFinal)(sqlite3_context*)
                                                            );
    SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
                                                             sqlite3 *db,
                                                             const char *zFunctionName,
                                                             int nArg,
                                                             int eTextRep,
                                                             void *pApp,
                                                             void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
                                                             void (*xStep)(sqlite3_context*,int,sqlite3_value**),
                                                             void (*xFinal)(sqlite3_context*),
                                                             void(*xDestroy)(void*)
                                                             );
    
    /*
     ** CAPI3REF: Text Encodings
     **
     ** These constant define integer codes that represent the various
     ** text encodings supported by SQLite.
     */
#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* Deprecated */
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
    
    /*
     ** CAPI3REF: Function Flags
     **
     ** These constants may be ORed together with the
     ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
     ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
     ** [sqlite3_create_function_v2()].
     */
#define SQLITE_DETERMINISTIC    0x800
    
    /*
     ** CAPI3REF: Deprecated Functions
     ** DEPRECATED
     **
     ** These functions are [deprecated].  In order to maintain
     ** backwards compatibility with older code, these functions continue
     ** to be supported.  However, new applications should avoid
     ** the use of these functions.  To encourage programmers to avoid
     ** these functions, we will not explain what they do.
     */
#ifndef SQLITE_OMIT_DEPRECATED
    SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*);
    SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*);
    SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
    SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void);
    SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void);
    SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
                                                                         void*,sqlite3_int64);
#endif
    
    /*
     ** CAPI3REF: Obtaining SQL Values
     ** METHOD: sqlite3_value
     **
     ** The C-language implementation of SQL functions and aggregates uses
     ** this set of interface routines to access the parameter values on
     ** the function or aggregate.
     **
     ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
     ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
     ** define callbacks that implement the SQL functions and aggregates.
     ** The 3rd parameter to these callbacks is an array of pointers to
     ** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
     ** each parameter to the SQL function.  These routines are used to
     ** extract values from the [sqlite3_value] objects.
     **
     ** These routines work only with [protected sqlite3_value] objects.
     ** Any attempt to use these routines on an [unprotected sqlite3_value]
     ** object results in undefined behavior.
     **
     ** ^These routines work just like the corresponding [column access functions]
     ** except that these routines take a single [protected sqlite3_value] object
     ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
     **
     ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
     ** in the native byte-order of the host machine.  ^The
     ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
     ** extract UTF-16 strings as big-endian and little-endian respectively.
     **
     ** ^(The sqlite3_value_numeric_type() interface attempts to apply
     ** numeric affinity to the value.  This means that an attempt is
     ** made to convert the value to an integer or floating point.  If
     ** such a conversion is possible without loss of information (in other
     ** words, if the value is a string that looks like a number)
     ** then the conversion is performed.  Otherwise no conversion occurs.
     ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
     **
     ** Please pay particular attention to the fact that the pointer returned
     ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
     ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
     ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
     ** or [sqlite3_value_text16()].
     **
     ** These routines must be called from the same thread as
     ** the SQL function that supplied the [sqlite3_value*] parameters.
     */
    SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*);
    SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*);
    SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*);
    SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*);
    SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*);
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*);
    SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*);
    SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*);
    SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*);
    SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*);
    
    /*
     ** CAPI3REF: Finding The Subtype Of SQL Values
     ** METHOD: sqlite3_value
     **
     ** The sqlite3_value_subtype(V) function returns the subtype for
     ** an [application-defined SQL function] argument V.  The subtype
     ** information can be used to pass a limited amount of context from
     ** one SQL function to another.  Use the [sqlite3_result_subtype()]
     ** routine to set the subtype for the return value of an SQL function.
     **
     ** SQLite makes no use of subtype itself.  It merely passes the subtype
     ** from the result of one [application-defined SQL function] into the
     ** input of another.
     */
    SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*);
    
    /*
     ** CAPI3REF: Copy And Free SQL Values
     ** METHOD: sqlite3_value
     **
     ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
     ** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
     ** is a [protected sqlite3_value] object even if the input is not.
     ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
     ** memory allocation fails.
     **
     ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
     ** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer
     ** then sqlite3_value_free(V) is a harmless no-op.
     */
    SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*);
    SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*);
    
    /*
     ** CAPI3REF: Obtain Aggregate Function Context
     ** METHOD: sqlite3_context
     **
     ** Implementations of aggregate SQL functions use this
     ** routine to allocate memory for storing their state.
     **
     ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
     ** for a particular aggregate function, SQLite
     ** allocates N of memory, zeroes out that memory, and returns a pointer
     ** to the new memory. ^On second and subsequent calls to
     ** sqlite3_aggregate_context() for the same aggregate function instance,
     ** the same buffer is returned.  Sqlite3_aggregate_context() is normally
     ** called once for each invocation of the xStep callback and then one
     ** last time when the xFinal callback is invoked.  ^(When no rows match
     ** an aggregate query, the xStep() callback of the aggregate function
     ** implementation is never called and xFinal() is called exactly once.
     ** In those cases, sqlite3_aggregate_context() might be called for the
     ** first time from within xFinal().)^
     **
     ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
     ** when first called if N is less than or equal to zero or if a memory
     ** allocate error occurs.
     **
     ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
     ** determined by the N parameter on first successful call.  Changing the
     ** value of N in subsequent call to sqlite3_aggregate_context() within
     ** the same aggregate function instance will not resize the memory
     ** allocation.)^  Within the xFinal callback, it is customary to set
     ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
     ** pointless memory allocations occur.
     **
     ** ^SQLite automatically frees the memory allocated by
     ** sqlite3_aggregate_context() when the aggregate query concludes.
     **
     ** The first parameter must be a copy of the
     ** [sqlite3_context | SQL function context] that is the first parameter
     ** to the xStep or xFinal callback routine that implements the aggregate
     ** function.
     **
     ** This routine must be called from the same thread in which
     ** the aggregate SQL function is running.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes);
    
    /*
     ** CAPI3REF: User Data For Functions
     ** METHOD: sqlite3_context
     **
     ** ^The sqlite3_user_data() interface returns a copy of
     ** the pointer that was the pUserData parameter (the 5th parameter)
     ** of the [sqlite3_create_function()]
     ** and [sqlite3_create_function16()] routines that originally
     ** registered the application defined function.
     **
     ** This routine must be called from the same thread in which
     ** the application-defined function is running.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*);
    
    /*
     ** CAPI3REF: Database Connection For Functions
     ** METHOD: sqlite3_context
     **
     ** ^The sqlite3_context_db_handle() interface returns a copy of
     ** the pointer to the [database connection] (the 1st parameter)
     ** of the [sqlite3_create_function()]
     ** and [sqlite3_create_function16()] routines that originally
     ** registered the application defined function.
     */
    SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*);
    
    /*
     ** CAPI3REF: Function Auxiliary Data
     ** METHOD: sqlite3_context
     **
     ** These functions may be used by (non-aggregate) SQL functions to
     ** associate metadata with argument values. If the same value is passed to
     ** multiple invocations of the same SQL function during query execution, under
     ** some circumstances the associated metadata may be preserved.  An example
     ** of where this might be useful is in a regular-expression matching
     ** function. The compiled version of the regular expression can be stored as
     ** metadata associated with the pattern string.
     ** Then as long as the pattern string remains the same,
     ** the compiled regular expression can be reused on multiple
     ** invocations of the same function.
     **
     ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
     ** associated by the sqlite3_set_auxdata() function with the Nth argument
     ** value to the application-defined function. ^If there is no metadata
     ** associated with the function argument, this sqlite3_get_auxdata() interface
     ** returns a NULL pointer.
     **
     ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
     ** argument of the application-defined function.  ^Subsequent
     ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
     ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
     ** NULL if the metadata has been discarded.
     ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
     ** SQLite will invoke the destructor function X with parameter P exactly
     ** once, when the metadata is discarded.
     ** SQLite is free to discard the metadata at any time, including: <ul>
     ** <li> when the corresponding function parameter changes, or
     ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
     **      SQL statement, or
     ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
     ** <li> during the original sqlite3_set_auxdata() call when a memory
     **      allocation error occurs. </ul>)^
     **
     ** Note the last bullet in particular.  The destructor X in
     ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
     ** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
     ** should be called near the end of the function implementation and the
     ** function implementation should not make any use of P after
     ** sqlite3_set_auxdata() has been called.
     **
     ** ^(In practice, metadata is preserved between function calls for
     ** function parameters that are compile-time constants, including literal
     ** values and [parameters] and expressions composed from the same.)^
     **
     ** These routines must be called from the same thread in which
     ** the SQL function is running.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N);
    SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
    
    
    /*
     ** CAPI3REF: Constants Defining Special Destructor Behavior
     **
     ** These are special values for the destructor that is passed in as the
     ** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
     ** argument is SQLITE_STATIC, it means that the content pointer is constant
     ** and will never change.  It does not need to be destroyed.  ^The
     ** SQLITE_TRANSIENT value means that the content will likely change in
     ** the near future and that SQLite should make its own private copy of
     ** the content before returning.
     **
     ** The typedef is necessary to work around problems in certain
     ** C++ compilers.
     */
    typedef void (*sqlite3_destructor_type)(void*);
#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
    
    /*
     ** CAPI3REF: Setting The Result Of An SQL Function
     ** METHOD: sqlite3_context
     **
     ** These routines are used by the xFunc or xFinal callbacks that
     ** implement SQL functions and aggregates.  See
     ** [sqlite3_create_function()] and [sqlite3_create_function16()]
     ** for additional information.
     **
     ** These functions work very much like the [parameter binding] family of
     ** functions used to bind values to host parameters in prepared statements.
     ** Refer to the [SQL parameter] documentation for additional information.
     **
     ** ^The sqlite3_result_blob() interface sets the result from
     ** an application-defined function to be the BLOB whose content is pointed
     ** to by the second parameter and which is N bytes long where N is the
     ** third parameter.
     **
     ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
     ** interfaces set the result of the application-defined function to be
     ** a BLOB containing all zero bytes and N bytes in size.
     **
     ** ^The sqlite3_result_double() interface sets the result from
     ** an application-defined function to be a floating point value specified
     ** by its 2nd argument.
     **
     ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
     ** cause the implemented SQL function to throw an exception.
     ** ^SQLite uses the string pointed to by the
     ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
     ** as the text of an error message.  ^SQLite interprets the error
     ** message string from sqlite3_result_error() as UTF-8. ^SQLite
     ** interprets the string from sqlite3_result_error16() as UTF-16 in native
     ** byte order.  ^If the third parameter to sqlite3_result_error()
     ** or sqlite3_result_error16() is negative then SQLite takes as the error
     ** message all text up through the first zero character.
     ** ^If the third parameter to sqlite3_result_error() or
     ** sqlite3_result_error16() is non-negative then SQLite takes that many
     ** bytes (not characters) from the 2nd parameter as the error message.
     ** ^The sqlite3_result_error() and sqlite3_result_error16()
     ** routines make a private copy of the error message text before
     ** they return.  Hence, the calling function can deallocate or
     ** modify the text after they return without harm.
     ** ^The sqlite3_result_error_code() function changes the error code
     ** returned by SQLite as a result of an error in a function.  ^By default,
     ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
     ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
     **
     ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
     ** error indicating that a string or BLOB is too long to represent.
     **
     ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
     ** error indicating that a memory allocation failed.
     **
     ** ^The sqlite3_result_int() interface sets the return value
     ** of the application-defined function to be the 32-bit signed integer
     ** value given in the 2nd argument.
     ** ^The sqlite3_result_int64() interface sets the return value
     ** of the application-defined function to be the 64-bit signed integer
     ** value given in the 2nd argument.
     **
     ** ^The sqlite3_result_null() interface sets the return value
     ** of the application-defined function to be NULL.
     **
     ** ^The sqlite3_result_text(), sqlite3_result_text16(),
     ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
     ** set the return value of the application-defined function to be
     ** a text string which is represented as UTF-8, UTF-16 native byte order,
     ** UTF-16 little endian, or UTF-16 big endian, respectively.
     ** ^The sqlite3_result_text64() interface sets the return value of an
     ** application-defined function to be a text string in an encoding
     ** specified by the fifth (and last) parameter, which must be one
     ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
     ** ^SQLite takes the text result from the application from
     ** the 2nd parameter of the sqlite3_result_text* interfaces.
     ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
     ** is negative, then SQLite takes result text from the 2nd parameter
     ** through the first zero character.
     ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
     ** is non-negative, then as many bytes (not characters) of the text
     ** pointed to by the 2nd parameter are taken as the application-defined
     ** function result.  If the 3rd parameter is non-negative, then it
     ** must be the byte offset into the string where the NUL terminator would
     ** appear if the string where NUL terminated.  If any NUL characters occur
     ** in the string at a byte offset that is less than the value of the 3rd
     ** parameter, then the resulting string will contain embedded NULs and the
     ** result of expressions operating on strings with embedded NULs is undefined.
     ** ^If the 4th parameter to the sqlite3_result_text* interfaces
     ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
     ** function as the destructor on the text or BLOB result when it has
     ** finished using that result.
     ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
     ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
     ** assumes that the text or BLOB result is in constant space and does not
     ** copy the content of the parameter nor call a destructor on the content
     ** when it has finished using that result.
     ** ^If the 4th parameter to the sqlite3_result_text* interfaces
     ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
     ** then SQLite makes a copy of the result into space obtained from
     ** from [sqlite3_malloc()] before it returns.
     **
     ** ^The sqlite3_result_value() interface sets the result of
     ** the application-defined function to be a copy of the
     ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
     ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
     ** so that the [sqlite3_value] specified in the parameter may change or
     ** be deallocated after sqlite3_result_value() returns without harm.
     ** ^A [protected sqlite3_value] object may always be used where an
     ** [unprotected sqlite3_value] object is required, so either
     ** kind of [sqlite3_value] object can be used with this interface.
     **
     ** If these routines are called from within the different thread
     ** than the one containing the application-defined function that received
     ** the [sqlite3_context] pointer, the results are undefined.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
    SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*,
                                                         sqlite3_uint64,void(*)(void*));
    SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
    SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
                                                         void(*)(void*), unsigned char encoding);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
    SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
    SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
    SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*);
    SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n);
    SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
    
    
    /*
     ** CAPI3REF: Setting The Subtype Of An SQL Function
     ** METHOD: sqlite3_context
     **
     ** The sqlite3_result_subtype(C,T) function causes the subtype of
     ** the result from the [application-defined SQL function] with
     ** [sqlite3_context] C to be the value T.  Only the lower 8 bits
     ** of the subtype T are preserved in current versions of SQLite;
     ** higher order bits are discarded.
     ** The number of subtype bytes preserved by SQLite might increase
     ** in future releases of SQLite.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int);
    
    /*
     ** CAPI3REF: Define New Collating Sequences
     ** METHOD: sqlite3
     **
     ** ^These functions add, remove, or modify a [collation] associated
     ** with the [database connection] specified as the first argument.
     **
     ** ^The name of the collation is a UTF-8 string
     ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
     ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
     ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
     ** considered to be the same name.
     **
     ** ^(The third argument (eTextRep) must be one of the constants:
     ** <ul>
     ** <li> [SQLITE_UTF8],
     ** <li> [SQLITE_UTF16LE],
     ** <li> [SQLITE_UTF16BE],
     ** <li> [SQLITE_UTF16], or
     ** <li> [SQLITE_UTF16_ALIGNED].
     ** </ul>)^
     ** ^The eTextRep argument determines the encoding of strings passed
     ** to the collating function callback, xCallback.
     ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
     ** force strings to be UTF16 with native byte order.
     ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
     ** on an even byte address.
     **
     ** ^The fourth argument, pArg, is an application data pointer that is passed
     ** through as the first argument to the collating function callback.
     **
     ** ^The fifth argument, xCallback, is a pointer to the collating function.
     ** ^Multiple collating functions can be registered using the same name but
     ** with different eTextRep parameters and SQLite will use whichever
     ** function requires the least amount of data transformation.
     ** ^If the xCallback argument is NULL then the collating function is
     ** deleted.  ^When all collating functions having the same name are deleted,
     ** that collation is no longer usable.
     **
     ** ^The collating function callback is invoked with a copy of the pArg
     ** application data pointer and with two strings in the encoding specified
     ** by the eTextRep argument.  The collating function must return an
     ** integer that is negative, zero, or positive
     ** if the first string is less than, equal to, or greater than the second,
     ** respectively.  A collating function must always return the same answer
     ** given the same inputs.  If two or more collating functions are registered
     ** to the same collation name (using different eTextRep values) then all
     ** must give an equivalent answer when invoked with equivalent strings.
     ** The collating function must obey the following properties for all
     ** strings A, B, and C:
     **
     ** <ol>
     ** <li> If A==B then B==A.
     ** <li> If A==B and B==C then A==C.
     ** <li> If A&lt;B THEN B&gt;A.
     ** <li> If A&lt;B and B&lt;C then A&lt;C.
     ** </ol>
     **
     ** If a collating function fails any of the above constraints and that
     ** collating function is  registered and used, then the behavior of SQLite
     ** is undefined.
     **
     ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
     ** with the addition that the xDestroy callback is invoked on pArg when
     ** the collating function is deleted.
     ** ^Collating functions are deleted when they are overridden by later
     ** calls to the collation creation functions or when the
     ** [database connection] is closed using [sqlite3_close()].
     **
     ** ^The xDestroy callback is <u>not</u> called if the
     ** sqlite3_create_collation_v2() function fails.  Applications that invoke
     ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
     ** check the return code and dispose of the application data pointer
     ** themselves rather than expecting SQLite to deal with it for them.
     ** This is different from every other SQLite interface.  The inconsistency
     ** is unfortunate but cannot be changed without breaking backwards
     ** compatibility.
     **
     ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_create_collation(
                                                           sqlite3*,
                                                           const char *zName,
                                                           int eTextRep,
                                                           void *pArg,
                                                           int(*xCompare)(void*,int,const void*,int,const void*)
                                                           );
    SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2(
                                                              sqlite3*,
                                                              const char *zName,
                                                              int eTextRep,
                                                              void *pArg,
                                                              int(*xCompare)(void*,int,const void*,int,const void*),
                                                              void(*xDestroy)(void*)
                                                              );
    SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16(
                                                             sqlite3*,
                                                             const void *zName,
                                                             int eTextRep,
                                                             void *pArg,
                                                             int(*xCompare)(void*,int,const void*,int,const void*)
                                                             );
    
    /*
     ** CAPI3REF: Collation Needed Callbacks
     ** METHOD: sqlite3
     **
     ** ^To avoid having to register all collation sequences before a database
     ** can be used, a single callback function may be registered with the
     ** [database connection] to be invoked whenever an undefined collation
     ** sequence is required.
     **
     ** ^If the function is registered using the sqlite3_collation_needed() API,
     ** then it is passed the names of undefined collation sequences as strings
     ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
     ** the names are passed as UTF-16 in machine native byte order.
     ** ^A call to either function replaces the existing collation-needed callback.
     **
     ** ^(When the callback is invoked, the first argument passed is a copy
     ** of the second argument to sqlite3_collation_needed() or
     ** sqlite3_collation_needed16().  The second argument is the database
     ** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
     ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
     ** sequence function required.  The fourth parameter is the name of the
     ** required collation sequence.)^
     **
     ** The callback function should register the desired collation using
     ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
     ** [sqlite3_create_collation_v2()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed(
                                                           sqlite3*,
                                                           void*,
                                                           void(*)(void*,sqlite3*,int eTextRep,const char*)
                                                           );
    SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16(
                                                             sqlite3*,
                                                             void*,
                                                             void(*)(void*,sqlite3*,int eTextRep,const void*)
                                                             );
    
#ifdef SQLITE_HAS_CODEC
    /*
     ** Specify the key for an encrypted database.  This routine should be
     ** called right after sqlite3_open().
     **
     ** The code to implement this API is not available in the public release
     ** of SQLite.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_key(
                                              sqlite3 *db,                   /* Database to be rekeyed */
                                              const void *pKey, int nKey     /* The key */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_key_v2(
                                                 sqlite3 *db,                   /* Database to be rekeyed */
                                                 const char *zDbName,           /* Name of the database */
                                                 const void *pKey, int nKey     /* The key */
    );
    
    /*
     ** Change the key on an open database.  If the current database is not
     ** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
     ** database is decrypted.
     **
     ** The code to implement this API is not available in the public release
     ** of SQLite.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_rekey(
                                                sqlite3 *db,                   /* Database to be rekeyed */
                                                const void *pKey, int nKey     /* The new key */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2(
                                                   sqlite3 *db,                   /* Database to be rekeyed */
                                                   const char *zDbName,           /* Name of the database */
                                                   const void *pKey, int nKey     /* The new key */
    );
    
    /*
     ** Specify the activation key for a SEE database.  Unless
     ** activated, none of the SEE routines will work.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_activate_see(
                                                        const char *zPassPhrase        /* Activation phrase */
    );
#endif
    
#ifdef SQLITE_ENABLE_CEROD
    /*
     ** Specify the activation key for a CEROD database.  Unless
     ** activated, none of the CEROD routines will work.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod(
                                                          const char *zPassPhrase        /* Activation phrase */
    );
#endif
    
    /*
     ** CAPI3REF: Suspend Execution For A Short Time
     **
     ** The sqlite3_sleep() function causes the current thread to suspend execution
     ** for at least a number of milliseconds specified in its parameter.
     **
     ** If the operating system does not support sleep requests with
     ** millisecond time resolution, then the time will be rounded up to
     ** the nearest second. The number of milliseconds of sleep actually
     ** requested from the operating system is returned.
     **
     ** ^SQLite implements this interface by calling the xSleep()
     ** method of the default [sqlite3_vfs] object.  If the xSleep() method
     ** of the default VFS is not implemented correctly, or not implemented at
     ** all, then the behavior of sqlite3_sleep() may deviate from the description
     ** in the previous paragraphs.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int);
    
    /*
     ** CAPI3REF: Name Of The Folder Holding Temporary Files
     **
     ** ^(If this global variable is made to point to a string which is
     ** the name of a folder (a.k.a. directory), then all temporary files
     ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
     ** will be placed in that directory.)^  ^If this variable
     ** is a NULL pointer, then SQLite performs a search for an appropriate
     ** temporary file directory.
     **
     ** Applications are strongly discouraged from using this global variable.
     ** It is required to set a temporary folder on Windows Runtime (WinRT).
     ** But for all other platforms, it is highly recommended that applications
     ** neither read nor write this variable.  This global variable is a relic
     ** that exists for backwards compatibility of legacy applications and should
     ** be avoided in new projects.
     **
     ** It is not safe to read or modify this variable in more than one
     ** thread at a time.  It is not safe to read or modify this variable
     ** if a [database connection] is being used at the same time in a separate
     ** thread.
     ** It is intended that this variable be set once
     ** as part of process initialization and before any SQLite interface
     ** routines have been called and that this variable remain unchanged
     ** thereafter.
     **
     ** ^The [temp_store_directory pragma] may modify this variable and cause
     ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
     ** the [temp_store_directory pragma] always assumes that any string
     ** that this variable points to is held in memory obtained from
     ** [sqlite3_malloc] and the pragma may attempt to free that memory
     ** using [sqlite3_free].
     ** Hence, if this variable is modified directly, either it should be
     ** made NULL or made to point to memory obtained from [sqlite3_malloc]
     ** or else the use of the [temp_store_directory pragma] should be avoided.
     ** Except when requested by the [temp_store_directory pragma], SQLite
     ** does not free the memory that sqlite3_temp_directory points to.  If
     ** the application wants that memory to be freed, it must do
     ** so itself, taking care to only do so after all [database connection]
     ** objects have been destroyed.
     **
     ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
     ** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
     ** features that require the use of temporary files may fail.  Here is an
     ** example of how to do this using C++ with the Windows Runtime:
     **
     ** <blockquote><pre>
     ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
     ** &nbsp;     TemporaryFolder->Path->Data();
     ** char zPathBuf&#91;MAX_PATH + 1&#93;;
     ** memset(zPathBuf, 0, sizeof(zPathBuf));
     ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
     ** &nbsp;     NULL, NULL);
     ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
     ** </pre></blockquote>
     */
    SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
    
    /*
     ** CAPI3REF: Name Of The Folder Holding Database Files
     **
     ** ^(If this global variable is made to point to a string which is
     ** the name of a folder (a.k.a. directory), then all database files
     ** specified with a relative pathname and created or accessed by
     ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
     ** to be relative to that directory.)^ ^If this variable is a NULL
     ** pointer, then SQLite assumes that all database files specified
     ** with a relative pathname are relative to the current directory
     ** for the process.  Only the windows VFS makes use of this global
     ** variable; it is ignored by the unix VFS.
     **
     ** Changing the value of this variable while a database connection is
     ** open can result in a corrupt database.
     **
     ** It is not safe to read or modify this variable in more than one
     ** thread at a time.  It is not safe to read or modify this variable
     ** if a [database connection] is being used at the same time in a separate
     ** thread.
     ** It is intended that this variable be set once
     ** as part of process initialization and before any SQLite interface
     ** routines have been called and that this variable remain unchanged
     ** thereafter.
     **
     ** ^The [data_store_directory pragma] may modify this variable and cause
     ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
     ** the [data_store_directory pragma] always assumes that any string
     ** that this variable points to is held in memory obtained from
     ** [sqlite3_malloc] and the pragma may attempt to free that memory
     ** using [sqlite3_free].
     ** Hence, if this variable is modified directly, either it should be
     ** made NULL or made to point to memory obtained from [sqlite3_malloc]
     ** or else the use of the [data_store_directory pragma] should be avoided.
     */
    SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
    
    /*
     ** CAPI3REF: Test For Auto-Commit Mode
     ** KEYWORDS: {autocommit mode}
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_get_autocommit() interface returns non-zero or
     ** zero if the given database connection is or is not in autocommit mode,
     ** respectively.  ^Autocommit mode is on by default.
     ** ^Autocommit mode is disabled by a [BEGIN] statement.
     ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
     **
     ** If certain kinds of errors occur on a statement within a multi-statement
     ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
     ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
     ** transaction might be rolled back automatically.  The only way to
     ** find out whether SQLite automatically rolled back the transaction after
     ** an error is to use this function.
     **
     ** If another thread changes the autocommit status of the database
     ** connection while this routine is running, then the return value
     ** is undefined.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*);
    
    /*
     ** CAPI3REF: Find The Database Handle Of A Prepared Statement
     ** METHOD: sqlite3_stmt
     **
     ** ^The sqlite3_db_handle interface returns the [database connection] handle
     ** to which a [prepared statement] belongs.  ^The [database connection]
     ** returned by sqlite3_db_handle is the same [database connection]
     ** that was the first argument
     ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
     ** create the statement in the first place.
     */
    SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*);
    
    /*
     ** CAPI3REF: Return The Filename For A Database Connection
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
     ** associated with database N of connection D.  ^The main database file
     ** has the name "main".  If there is no attached database N on the database
     ** connection D, or if database N is a temporary or in-memory database, then
     ** a NULL pointer is returned.
     **
     ** ^The filename returned by this function is the output of the
     ** xFullPathname method of the [VFS].  ^In other words, the filename
     ** will be an absolute pathname, even if the filename used
     ** to open the database originally was a URI or relative pathname.
     */
    SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName);
    
    /*
     ** CAPI3REF: Determine if a database is read-only
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
     ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
     ** the name of a database on connection D.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
    
    /*
     ** CAPI3REF: Find the next prepared statement
     ** METHOD: sqlite3
     **
     ** ^This interface returns a pointer to the next [prepared statement] after
     ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
     ** then this interface returns a pointer to the first prepared statement
     ** associated with the database connection pDb.  ^If no prepared statement
     ** satisfies the conditions of this routine, it returns NULL.
     **
     ** The [database connection] pointer D in a call to
     ** [sqlite3_next_stmt(D,S)] must refer to an open database
     ** connection and in particular must not be a NULL pointer.
     */
    SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
    
    /*
     ** CAPI3REF: Commit And Rollback Notification Callbacks
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_commit_hook() interface registers a callback
     ** function to be invoked whenever a transaction is [COMMIT | committed].
     ** ^Any callback set by a previous call to sqlite3_commit_hook()
     ** for the same database connection is overridden.
     ** ^The sqlite3_rollback_hook() interface registers a callback
     ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
     ** ^Any callback set by a previous call to sqlite3_rollback_hook()
     ** for the same database connection is overridden.
     ** ^The pArg argument is passed through to the callback.
     ** ^If the callback on a commit hook function returns non-zero,
     ** then the commit is converted into a rollback.
     **
     ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
     ** return the P argument from the previous call of the same function
     ** on the same [database connection] D, or NULL for
     ** the first call for each function on D.
     **
     ** The commit and rollback hook callbacks are not reentrant.
     ** The callback implementation must not do anything that will modify
     ** the database connection that invoked the callback.  Any actions
     ** to modify the database connection must be deferred until after the
     ** completion of the [sqlite3_step()] call that triggered the commit
     ** or rollback hook in the first place.
     ** Note that running any other SQL statements, including SELECT statements,
     ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
     ** the database connections for the meaning of "modify" in this paragraph.
     **
     ** ^Registering a NULL function disables the callback.
     **
     ** ^When the commit hook callback routine returns zero, the [COMMIT]
     ** operation is allowed to continue normally.  ^If the commit hook
     ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
     ** ^The rollback hook is invoked on a rollback that results from a commit
     ** hook returning non-zero, just as it would be with any other rollback.
     **
     ** ^For the purposes of this API, a transaction is said to have been
     ** rolled back if an explicit "ROLLBACK" statement is executed, or
     ** an error or constraint causes an implicit rollback to occur.
     ** ^The rollback callback is not invoked if a transaction is
     ** automatically rolled back because the database connection is closed.
     **
     ** See also the [sqlite3_update_hook()] interface.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
    SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
    
    /*
     ** CAPI3REF: Data Change Notification Callbacks
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_update_hook() interface registers a callback function
     ** with the [database connection] identified by the first argument
     ** to be invoked whenever a row is updated, inserted or deleted in
     ** a rowid table.
     ** ^Any callback set by a previous call to this function
     ** for the same database connection is overridden.
     **
     ** ^The second argument is a pointer to the function to invoke when a
     ** row is updated, inserted or deleted in a rowid table.
     ** ^The first argument to the callback is a copy of the third argument
     ** to sqlite3_update_hook().
     ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
     ** or [SQLITE_UPDATE], depending on the operation that caused the callback
     ** to be invoked.
     ** ^The third and fourth arguments to the callback contain pointers to the
     ** database and table name containing the affected row.
     ** ^The final callback parameter is the [rowid] of the row.
     ** ^In the case of an update, this is the [rowid] after the update takes place.
     **
     ** ^(The update hook is not invoked when internal system tables are
     ** modified (i.e. sqlite_master and sqlite_sequence).)^
     ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
     **
     ** ^In the current implementation, the update hook
     ** is not invoked when duplication rows are deleted because of an
     ** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
     ** invoked when rows are deleted using the [truncate optimization].
     ** The exceptions defined in this paragraph might change in a future
     ** release of SQLite.
     **
     ** The update hook implementation must not do anything that will modify
     ** the database connection that invoked the update hook.  Any actions
     ** to modify the database connection must be deferred until after the
     ** completion of the [sqlite3_step()] call that triggered the update hook.
     ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
     ** database connections for the meaning of "modify" in this paragraph.
     **
     ** ^The sqlite3_update_hook(D,C,P) function
     ** returns the P argument from the previous call
     ** on the same [database connection] D, or NULL for
     ** the first call on D.
     **
     ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
     ** interfaces.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook(
                                                        sqlite3*,
                                                        void(*)(void *,int ,char const *,char const *,sqlite3_int64),
                                                        void*
                                                        );
    
    /*
     ** CAPI3REF: Enable Or Disable Shared Pager Cache
     **
     ** ^(This routine enables or disables the sharing of the database cache
     ** and schema data structures between [database connection | connections]
     ** to the same database. Sharing is enabled if the argument is true
     ** and disabled if the argument is false.)^
     **
     ** ^Cache sharing is enabled and disabled for an entire process.
     ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
     ** sharing was enabled or disabled for each thread separately.
     **
     ** ^(The cache sharing mode set by this interface effects all subsequent
     ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
     ** Existing database connections continue use the sharing mode
     ** that was in effect at the time they were opened.)^
     **
     ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
     ** successfully.  An [error code] is returned otherwise.)^
     **
     ** ^Shared cache is disabled by default. But this might change in
     ** future releases of SQLite.  Applications that care about shared
     ** cache setting should set it explicitly.
     **
     ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
     ** and will always return SQLITE_MISUSE. On those systems,
     ** shared cache mode should be enabled per-database connection via
     ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
     **
     ** This interface is threadsafe on processors where writing a
     ** 32-bit integer is atomic.
     **
     ** See Also:  [SQLite Shared-Cache Mode]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int);
    
    /*
     ** CAPI3REF: Attempt To Free Heap Memory
     **
     ** ^The sqlite3_release_memory() interface attempts to free N bytes
     ** of heap memory by deallocating non-essential memory allocations
     ** held by the database library.   Memory used to cache database
     ** pages to improve performance is an example of non-essential memory.
     ** ^sqlite3_release_memory() returns the number of bytes actually freed,
     ** which might be more or less than the amount requested.
     ** ^The sqlite3_release_memory() routine is a no-op returning zero
     ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
     **
     ** See also: [sqlite3_db_release_memory()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int);
    
    /*
     ** CAPI3REF: Free Memory Used By A Database Connection
     ** METHOD: sqlite3
     **
     ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
     ** memory as possible from database connection D. Unlike the
     ** [sqlite3_release_memory()] interface, this interface is in effect even
     ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
     ** omitted.
     **
     ** See also: [sqlite3_release_memory()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*);
    
    /*
     ** CAPI3REF: Impose A Limit On Heap Size
     **
     ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
     ** soft limit on the amount of heap memory that may be allocated by SQLite.
     ** ^SQLite strives to keep heap memory utilization below the soft heap
     ** limit by reducing the number of pages held in the page cache
     ** as heap memory usages approaches the limit.
     ** ^The soft heap limit is "soft" because even though SQLite strives to stay
     ** below the limit, it will exceed the limit rather than generate
     ** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
     ** is advisory only.
     **
     ** ^The return value from sqlite3_soft_heap_limit64() is the size of
     ** the soft heap limit prior to the call, or negative in the case of an
     ** error.  ^If the argument N is negative
     ** then no change is made to the soft heap limit.  Hence, the current
     ** size of the soft heap limit can be determined by invoking
     ** sqlite3_soft_heap_limit64() with a negative argument.
     **
     ** ^If the argument N is zero then the soft heap limit is disabled.
     **
     ** ^(The soft heap limit is not enforced in the current implementation
     ** if one or more of following conditions are true:
     **
     ** <ul>
     ** <li> The soft heap limit is set to zero.
     ** <li> Memory accounting is disabled using a combination of the
     **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
     **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
     ** <li> An alternative page cache implementation is specified using
     **      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
     ** <li> The page cache allocates from its own memory pool supplied
     **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
     **      from the heap.
     ** </ul>)^
     **
     ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
     ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
     ** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
     ** the soft heap limit is enforced on every memory allocation.  Without
     ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
     ** when memory is allocated by the page cache.  Testing suggests that because
     ** the page cache is the predominate memory user in SQLite, most
     ** applications will achieve adequate soft heap limit enforcement without
     ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
     **
     ** The circumstances under which SQLite will enforce the soft heap limit may
     ** changes in future releases of SQLite.
     */
    SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N);
    
    /*
     ** CAPI3REF: Deprecated Soft Heap Limit Interface
     ** DEPRECATED
     **
     ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
     ** interface.  This routine is provided for historical compatibility
     ** only.  All new applications should use the
     ** [sqlite3_soft_heap_limit64()] interface rather than this one.
     */
    SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N);
    
    
    /*
     ** CAPI3REF: Extract Metadata About A Column Of A Table
     ** METHOD: sqlite3
     **
     ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
     ** information about column C of table T in database D
     ** on [database connection] X.)^  ^The sqlite3_table_column_metadata()
     ** interface returns SQLITE_OK and fills in the non-NULL pointers in
     ** the final five arguments with appropriate values if the specified
     ** column exists.  ^The sqlite3_table_column_metadata() interface returns
     ** SQLITE_ERROR and if the specified column does not exist.
     ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
     ** NULL pointer, then this routine simply checks for the existance of the
     ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
     ** does not.
     **
     ** ^The column is identified by the second, third and fourth parameters to
     ** this function. ^(The second parameter is either the name of the database
     ** (i.e. "main", "temp", or an attached database) containing the specified
     ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
     ** for the table using the same algorithm used by the database engine to
     ** resolve unqualified table references.
     **
     ** ^The third and fourth parameters to this function are the table and column
     ** name of the desired column, respectively.
     **
     ** ^Metadata is returned by writing to the memory locations passed as the 5th
     ** and subsequent parameters to this function. ^Any of these arguments may be
     ** NULL, in which case the corresponding element of metadata is omitted.
     **
     ** ^(<blockquote>
     ** <table border="1">
     ** <tr><th> Parameter <th> Output<br>Type <th>  Description
     **
     ** <tr><td> 5th <td> const char* <td> Data type
     ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
     ** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
     ** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
     ** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
     ** </table>
     ** </blockquote>)^
     **
     ** ^The memory pointed to by the character pointers returned for the
     ** declaration type and collation sequence is valid until the next
     ** call to any SQLite API function.
     **
     ** ^If the specified table is actually a view, an [error code] is returned.
     **
     ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
     ** is not a [WITHOUT ROWID] table and an
     ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
     ** parameters are set for the explicitly declared column. ^(If there is no
     ** [INTEGER PRIMARY KEY] column, then the outputs
     ** for the [rowid] are set as follows:
     **
     ** <pre>
     **     data type: "INTEGER"
     **     collation sequence: "BINARY"
     **     not null: 0
     **     primary key: 1
     **     auto increment: 0
     ** </pre>)^
     **
     ** ^This function causes all database schemas to be read from disk and
     ** parsed, if that has not already been done, and returns an error if
     ** any errors are encountered while loading the schema.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata(
                                                                sqlite3 *db,                /* Connection handle */
                                                                const char *zDbName,        /* Database name or NULL */
                                                                const char *zTableName,     /* Table name */
                                                                const char *zColumnName,    /* Column name */
                                                                char const **pzDataType,    /* OUTPUT: Declared data type */
                                                                char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
                                                                int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
                                                                int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
                                                                int *pAutoinc               /* OUTPUT: True if column is auto-increment */
    );
    
    /*
     ** CAPI3REF: Load An Extension
     ** METHOD: sqlite3
     **
     ** ^This interface loads an SQLite extension library from the named file.
     **
     ** ^The sqlite3_load_extension() interface attempts to load an
     ** [SQLite extension] library contained in the file zFile.  If
     ** the file cannot be loaded directly, attempts are made to load
     ** with various operating-system specific extensions added.
     ** So for example, if "samplelib" cannot be loaded, then names like
     ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
     ** be tried also.
     **
     ** ^The entry point is zProc.
     ** ^(zProc may be 0, in which case SQLite will try to come up with an
     ** entry point name on its own.  It first tries "sqlite3_extension_init".
     ** If that does not work, it constructs a name "sqlite3_X_init" where the
     ** X is consists of the lower-case equivalent of all ASCII alphabetic
     ** characters in the filename from the last "/" to the first following
     ** "." and omitting any initial "lib".)^
     ** ^The sqlite3_load_extension() interface returns
     ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
     ** ^If an error occurs and pzErrMsg is not 0, then the
     ** [sqlite3_load_extension()] interface shall attempt to
     ** fill *pzErrMsg with error message text stored in memory
     ** obtained from [sqlite3_malloc()]. The calling function
     ** should free this memory by calling [sqlite3_free()].
     **
     ** ^Extension loading must be enabled using
     ** [sqlite3_enable_load_extension()] prior to calling this API,
     ** otherwise an error will be returned.
     **
     ** See also the [load_extension() SQL function].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_load_extension(
                                                         sqlite3 *db,          /* Load the extension into this database connection */
                                                         const char *zFile,    /* Name of the shared library containing extension */
                                                         const char *zProc,    /* Entry point.  Derived from zFile if 0 */
                                                         char **pzErrMsg       /* Put error message here if not 0 */
    );
    
    /*
     ** CAPI3REF: Enable Or Disable Extension Loading
     ** METHOD: sqlite3
     **
     ** ^So as not to open security holes in older applications that are
     ** unprepared to deal with [extension loading], and as a means of disabling
     ** [extension loading] while evaluating user-entered SQL, the following API
     ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
     **
     ** ^Extension loading is off by default.
     ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
     ** to turn extension loading on and call it with onoff==0 to turn
     ** it back off again.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff);
    
    /*
     ** CAPI3REF: Automatically Load Statically Linked Extensions
     **
     ** ^This interface causes the xEntryPoint() function to be invoked for
     ** each new [database connection] that is created.  The idea here is that
     ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
     ** that is to be automatically loaded into all new database connections.
     **
     ** ^(Even though the function prototype shows that xEntryPoint() takes
     ** no arguments and returns void, SQLite invokes xEntryPoint() with three
     ** arguments and expects and integer result as if the signature of the
     ** entry point where as follows:
     **
     ** <blockquote><pre>
     ** &nbsp;  int xEntryPoint(
     ** &nbsp;    sqlite3 *db,
     ** &nbsp;    const char **pzErrMsg,
     ** &nbsp;    const struct sqlite3_api_routines *pThunk
     ** &nbsp;  );
     ** </pre></blockquote>)^
     **
     ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
     ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
     ** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
     ** is NULL before calling the xEntryPoint().  ^SQLite will invoke
     ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
     ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
     ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
     **
     ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
     ** on the list of automatic extensions is a harmless no-op. ^No entry point
     ** will be called more than once for each database connection that is opened.
     **
     ** See also: [sqlite3_reset_auto_extension()]
     ** and [sqlite3_cancel_auto_extension()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void));
    
    /*
     ** CAPI3REF: Cancel Automatic Extension Loading
     **
     ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
     ** initialization routine X that was registered using a prior call to
     ** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
     ** routine returns 1 if initialization routine X was successfully
     ** unregistered and it returns 0 if X was not on the list of initialization
     ** routines.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
    
    /*
     ** CAPI3REF: Reset Automatic Extension Loading
     **
     ** ^This interface disables all automatic extensions previously
     ** registered using [sqlite3_auto_extension()].
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void);
    
    /*
     ** The interface to the virtual-table mechanism is currently considered
     ** to be experimental.  The interface might change in incompatible ways.
     ** If this is a problem for you, do not use the interface at this time.
     **
     ** When the virtual-table mechanism stabilizes, we will declare the
     ** interface fixed, support it indefinitely, and remove this comment.
     */
    
    /*
     ** Structures used by the virtual table interface
     */
    typedef struct sqlite3_vtab sqlite3_vtab;
    typedef struct sqlite3_index_info sqlite3_index_info;
    typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
    typedef struct sqlite3_module sqlite3_module;
    
    /*
     ** CAPI3REF: Virtual Table Object
     ** KEYWORDS: sqlite3_module {virtual table module}
     **
     ** This structure, sometimes called a "virtual table module",
     ** defines the implementation of a [virtual tables].
     ** This structure consists mostly of methods for the module.
     **
     ** ^A virtual table module is created by filling in a persistent
     ** instance of this structure and passing a pointer to that instance
     ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
     ** ^The registration remains valid until it is replaced by a different
     ** module or until the [database connection] closes.  The content
     ** of this structure must not change while it is registered with
     ** any database connection.
     */
    struct sqlite3_module {
        int iVersion;
        int (*xCreate)(sqlite3*, void *pAux,
                       int argc, const char *const*argv,
                       sqlite3_vtab **ppVTab, char**);
        int (*xConnect)(sqlite3*, void *pAux,
                        int argc, const char *const*argv,
                        sqlite3_vtab **ppVTab, char**);
        int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
        int (*xDisconnect)(sqlite3_vtab *pVTab);
        int (*xDestroy)(sqlite3_vtab *pVTab);
        int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
        int (*xClose)(sqlite3_vtab_cursor*);
        int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
                       int argc, sqlite3_value **argv);
        int (*xNext)(sqlite3_vtab_cursor*);
        int (*xEof)(sqlite3_vtab_cursor*);
        int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
        int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
        int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
        int (*xBegin)(sqlite3_vtab *pVTab);
        int (*xSync)(sqlite3_vtab *pVTab);
        int (*xCommit)(sqlite3_vtab *pVTab);
        int (*xRollback)(sqlite3_vtab *pVTab);
        int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
                             void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                             void **ppArg);
        int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
        /* The methods above are in version 1 of the sqlite_module object. Those
         ** below are for version 2 and greater. */
        int (*xSavepoint)(sqlite3_vtab *pVTab, int);
        int (*xRelease)(sqlite3_vtab *pVTab, int);
        int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
    };
    
    /*
     ** CAPI3REF: Virtual Table Indexing Information
     ** KEYWORDS: sqlite3_index_info
     **
     ** The sqlite3_index_info structure and its substructures is used as part
     ** of the [virtual table] interface to
     ** pass information into and receive the reply from the [xBestIndex]
     ** method of a [virtual table module].  The fields under **Inputs** are the
     ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
     ** results into the **Outputs** fields.
     **
     ** ^(The aConstraint[] array records WHERE clause constraints of the form:
     **
     ** <blockquote>column OP expr</blockquote>
     **
     ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
     ** stored in aConstraint[].op using one of the
     ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
     ** ^(The index of the column is stored in
     ** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
     ** expr on the right-hand side can be evaluated (and thus the constraint
     ** is usable) and false if it cannot.)^
     **
     ** ^The optimizer automatically inverts terms of the form "expr OP column"
     ** and makes other simplifications to the WHERE clause in an attempt to
     ** get as many WHERE clause terms into the form shown above as possible.
     ** ^The aConstraint[] array only reports WHERE clause terms that are
     ** relevant to the particular virtual table being queried.
     **
     ** ^Information about the ORDER BY clause is stored in aOrderBy[].
     ** ^Each term of aOrderBy records a column of the ORDER BY clause.
     **
     ** The colUsed field indicates which columns of the virtual table may be
     ** required by the current scan. Virtual table columns are numbered from
     ** zero in the order in which they appear within the CREATE TABLE statement
     ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
     ** the corresponding bit is set within the colUsed mask if the column may be
     ** required by SQLite. If the table has at least 64 columns and any column
     ** to the right of the first 63 is required, then bit 63 of colUsed is also
     ** set. In other words, column iCol may be required if the expression
     ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
     ** non-zero.
     **
     ** The [xBestIndex] method must fill aConstraintUsage[] with information
     ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
     ** the right-hand side of the corresponding aConstraint[] is evaluated
     ** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
     ** is true, then the constraint is assumed to be fully handled by the
     ** virtual table and is not checked again by SQLite.)^
     **
     ** ^The idxNum and idxPtr values are recorded and passed into the
     ** [xFilter] method.
     ** ^[sqlite3_free()] is used to free idxPtr if and only if
     ** needToFreeIdxPtr is true.
     **
     ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
     ** the correct order to satisfy the ORDER BY clause so that no separate
     ** sorting step is required.
     **
     ** ^The estimatedCost value is an estimate of the cost of a particular
     ** strategy. A cost of N indicates that the cost of the strategy is similar
     ** to a linear scan of an SQLite table with N rows. A cost of log(N)
     ** indicates that the expense of the operation is similar to that of a
     ** binary search on a unique indexed field of an SQLite table with N rows.
     **
     ** ^The estimatedRows value is an estimate of the number of rows that
     ** will be returned by the strategy.
     **
     ** The xBestIndex method may optionally populate the idxFlags field with a
     ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
     ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
     ** assumes that the strategy may visit at most one row.
     **
     ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
     ** SQLite also assumes that if a call to the xUpdate() method is made as
     ** part of the same statement to delete or update a virtual table row and the
     ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
     ** any database changes. In other words, if the xUpdate() returns
     ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
     ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
     ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
     ** the xUpdate method are automatically rolled back by SQLite.
     **
     ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
     ** structure for SQLite version 3.8.2. If a virtual table extension is
     ** used with an SQLite version earlier than 3.8.2, the results of attempting
     ** to read or write the estimatedRows field are undefined (but are likely
     ** to included crashing the application). The estimatedRows field should
     ** therefore only be used if [sqlite3_libversion_number()] returns a
     ** value greater than or equal to 3008002. Similarly, the idxFlags field
     ** was added for version 3.9.0. It may therefore only be used if
     ** sqlite3_libversion_number() returns a value greater than or equal to
     ** 3009000.
     */
    struct sqlite3_index_info {
        /* Inputs */
        int nConstraint;           /* Number of entries in aConstraint */
        struct sqlite3_index_constraint {
            int iColumn;              /* Column constrained.  -1 for ROWID */
            unsigned char op;         /* Constraint operator */
            unsigned char usable;     /* True if this constraint is usable */
            int iTermOffset;          /* Used internally - xBestIndex should ignore */
        } *aConstraint;            /* Table of WHERE clause constraints */
        int nOrderBy;              /* Number of terms in the ORDER BY clause */
        struct sqlite3_index_orderby {
            int iColumn;              /* Column number */
            unsigned char desc;       /* True for DESC.  False for ASC. */
        } *aOrderBy;               /* The ORDER BY clause */
        /* Outputs */
        struct sqlite3_index_constraint_usage {
            int argvIndex;           /* if >0, constraint is part of argv to xFilter */
            unsigned char omit;      /* Do not code a test for this constraint */
        } *aConstraintUsage;
        int idxNum;                /* Number used to identify the index */
        char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
        int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
        int orderByConsumed;       /* True if output is already ordered */
        double estimatedCost;           /* Estimated cost of using this index */
        /* Fields below are only available in SQLite 3.8.2 and later */
        sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
        /* Fields below are only available in SQLite 3.9.0 and later */
        int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
        /* Fields below are only available in SQLite 3.10.0 and later */
        sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */
    };
    
    /*
     ** CAPI3REF: Virtual Table Scan Flags
     */
#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */
    
    /*
     ** CAPI3REF: Virtual Table Constraint Operator Codes
     **
     ** These macros defined the allowed values for the
     ** [sqlite3_index_info].aConstraint[].op field.  Each value represents
     ** an operator that is part of a constraint term in the wHERE clause of
     ** a query that uses a [virtual table].
     */
#define SQLITE_INDEX_CONSTRAINT_EQ      2
#define SQLITE_INDEX_CONSTRAINT_GT      4
#define SQLITE_INDEX_CONSTRAINT_LE      8
#define SQLITE_INDEX_CONSTRAINT_LT     16
#define SQLITE_INDEX_CONSTRAINT_GE     32
#define SQLITE_INDEX_CONSTRAINT_MATCH  64
#define SQLITE_INDEX_CONSTRAINT_LIKE   65
#define SQLITE_INDEX_CONSTRAINT_GLOB   66
#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
    
    /*
     ** CAPI3REF: Register A Virtual Table Implementation
     ** METHOD: sqlite3
     **
     ** ^These routines are used to register a new [virtual table module] name.
     ** ^Module names must be registered before
     ** creating a new [virtual table] using the module and before using a
     ** preexisting [virtual table] for the module.
     **
     ** ^The module name is registered on the [database connection] specified
     ** by the first parameter.  ^The name of the module is given by the
     ** second parameter.  ^The third parameter is a pointer to
     ** the implementation of the [virtual table module].   ^The fourth
     ** parameter is an arbitrary client data pointer that is passed through
     ** into the [xCreate] and [xConnect] methods of the virtual table module
     ** when a new virtual table is be being created or reinitialized.
     **
     ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
     ** is a pointer to a destructor for the pClientData.  ^SQLite will
     ** invoke the destructor function (if it is not NULL) when SQLite
     ** no longer needs the pClientData pointer.  ^The destructor will also
     ** be invoked if the call to sqlite3_create_module_v2() fails.
     ** ^The sqlite3_create_module()
     ** interface is equivalent to sqlite3_create_module_v2() with a NULL
     ** destructor.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_create_module(
                                                        sqlite3 *db,               /* SQLite connection to register module with */
                                                        const char *zName,         /* Name of the module */
                                                        const sqlite3_module *p,   /* Methods for the module */
                                                        void *pClientData          /* Client data for xCreate/xConnect */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2(
                                                           sqlite3 *db,               /* SQLite connection to register module with */
                                                           const char *zName,         /* Name of the module */
                                                           const sqlite3_module *p,   /* Methods for the module */
                                                           void *pClientData,         /* Client data for xCreate/xConnect */
                                                           void(*xDestroy)(void*)     /* Module destructor function */
    );
    
    /*
     ** CAPI3REF: Virtual Table Instance Object
     ** KEYWORDS: sqlite3_vtab
     **
     ** Every [virtual table module] implementation uses a subclass
     ** of this object to describe a particular instance
     ** of the [virtual table].  Each subclass will
     ** be tailored to the specific needs of the module implementation.
     ** The purpose of this superclass is to define certain fields that are
     ** common to all module implementations.
     **
     ** ^Virtual tables methods can set an error message by assigning a
     ** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
     ** take care that any prior string is freed by a call to [sqlite3_free()]
     ** prior to assigning a new string to zErrMsg.  ^After the error message
     ** is delivered up to the client application, the string will be automatically
     ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
     */
    struct sqlite3_vtab {
        const sqlite3_module *pModule;  /* The module for this virtual table */
        int nRef;                       /* Number of open cursors */
        char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
        /* Virtual table implementations will typically add additional fields */
    };
    
    /*
     ** CAPI3REF: Virtual Table Cursor Object
     ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
     **
     ** Every [virtual table module] implementation uses a subclass of the
     ** following structure to describe cursors that point into the
     ** [virtual table] and are used
     ** to loop through the virtual table.  Cursors are created using the
     ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
     ** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
     ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
     ** of the module.  Each module implementation will define
     ** the content of a cursor structure to suit its own needs.
     **
     ** This superclass exists in order to define fields of the cursor that
     ** are common to all implementations.
     */
    struct sqlite3_vtab_cursor {
        sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
        /* Virtual table implementations will typically add additional fields */
    };
    
    /*
     ** CAPI3REF: Declare The Schema Of A Virtual Table
     **
     ** ^The [xCreate] and [xConnect] methods of a
     ** [virtual table module] call this interface
     ** to declare the format (the names and datatypes of the columns) of
     ** the virtual tables they implement.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL);
    
    /*
     ** CAPI3REF: Overload A Function For A Virtual Table
     ** METHOD: sqlite3
     **
     ** ^(Virtual tables can provide alternative implementations of functions
     ** using the [xFindFunction] method of the [virtual table module].
     ** But global versions of those functions
     ** must exist in order to be overloaded.)^
     **
     ** ^(This API makes sure a global version of a function with a particular
     ** name and number of parameters exists.  If no such function exists
     ** before this API is called, a new function is created.)^  ^The implementation
     ** of the new function always causes an exception to be thrown.  So
     ** the new function is not good for anything by itself.  Its only
     ** purpose is to be a placeholder function that can be overloaded
     ** by a [virtual table].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
    
    /*
     ** The interface to the virtual-table mechanism defined above (back up
     ** to a comment remarkably similar to this one) is currently considered
     ** to be experimental.  The interface might change in incompatible ways.
     ** If this is a problem for you, do not use the interface at this time.
     **
     ** When the virtual-table mechanism stabilizes, we will declare the
     ** interface fixed, support it indefinitely, and remove this comment.
     */
    
    /*
     ** CAPI3REF: A Handle To An Open BLOB
     ** KEYWORDS: {BLOB handle} {BLOB handles}
     **
     ** An instance of this object represents an open BLOB on which
     ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
     ** ^Objects of this type are created by [sqlite3_blob_open()]
     ** and destroyed by [sqlite3_blob_close()].
     ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
     ** can be used to read or write small subsections of the BLOB.
     ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
     */
    typedef struct sqlite3_blob sqlite3_blob;
    
    /*
     ** CAPI3REF: Open A BLOB For Incremental I/O
     ** METHOD: sqlite3
     ** CONSTRUCTOR: sqlite3_blob
     **
     ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
     ** in row iRow, column zColumn, table zTable in database zDb;
     ** in other words, the same BLOB that would be selected by:
     **
     ** <pre>
     **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
     ** </pre>)^
     **
     ** ^(Parameter zDb is not the filename that contains the database, but
     ** rather the symbolic name of the database. For attached databases, this is
     ** the name that appears after the AS keyword in the [ATTACH] statement.
     ** For the main database file, the database name is "main". For TEMP
     ** tables, the database name is "temp".)^
     **
     ** ^If the flags parameter is non-zero, then the BLOB is opened for read
     ** and write access. ^If the flags parameter is zero, the BLOB is opened for
     ** read-only access.
     **
     ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
     ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
     ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
     ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
     ** on *ppBlob after this function it returns.
     **
     ** This function fails with SQLITE_ERROR if any of the following are true:
     ** <ul>
     **   <li> ^(Database zDb does not exist)^,
     **   <li> ^(Table zTable does not exist within database zDb)^,
     **   <li> ^(Table zTable is a WITHOUT ROWID table)^,
     **   <li> ^(Column zColumn does not exist)^,
     **   <li> ^(Row iRow is not present in the table)^,
     **   <li> ^(The specified column of row iRow contains a value that is not
     **         a TEXT or BLOB value)^,
     **   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
     **         constraint and the blob is being opened for read/write access)^,
     **   <li> ^([foreign key constraints | Foreign key constraints] are enabled,
     **         column zColumn is part of a [child key] definition and the blob is
     **         being opened for read/write access)^.
     ** </ul>
     **
     ** ^Unless it returns SQLITE_MISUSE, this function sets the
     ** [database connection] error code and message accessible via
     ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
     **
     **
     ** ^(If the row that a BLOB handle points to is modified by an
     ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
     ** then the BLOB handle is marked as "expired".
     ** This is true if any column of the row is changed, even a column
     ** other than the one the BLOB handle is open on.)^
     ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
     ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
     ** ^(Changes written into a BLOB prior to the BLOB expiring are not
     ** rolled back by the expiration of the BLOB.  Such changes will eventually
     ** commit if the transaction continues to completion.)^
     **
     ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
     ** the opened blob.  ^The size of a blob may not be changed by this
     ** interface.  Use the [UPDATE] SQL command to change the size of a
     ** blob.
     **
     ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
     ** and the built-in [zeroblob] SQL function may be used to create a
     ** zero-filled blob to read or write using the incremental-blob interface.
     **
     ** To avoid a resource leak, every open [BLOB handle] should eventually
     ** be released by a call to [sqlite3_blob_close()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_blob_open(
                                                    sqlite3*,
                                                    const char *zDb,
                                                    const char *zTable,
                                                    const char *zColumn,
                                                    sqlite3_int64 iRow,
                                                    int flags,
                                                    sqlite3_blob **ppBlob
                                                    );
    
    /*
     ** CAPI3REF: Move a BLOB Handle to a New Row
     ** METHOD: sqlite3_blob
     **
     ** ^This function is used to move an existing blob handle so that it points
     ** to a different row of the same database table. ^The new row is identified
     ** by the rowid value passed as the second argument. Only the row can be
     ** changed. ^The database, table and column on which the blob handle is open
     ** remain the same. Moving an existing blob handle to a new row can be
     ** faster than closing the existing handle and opening a new one.
     **
     ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
     ** it must exist and there must be either a blob or text value stored in
     ** the nominated column.)^ ^If the new row is not present in the table, or if
     ** it does not contain a blob or text value, or if another error occurs, an
     ** SQLite error code is returned and the blob handle is considered aborted.
     ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
     ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
     ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
     ** always returns zero.
     **
     ** ^This function sets the database handle error code and message.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
    
    /*
     ** CAPI3REF: Close A BLOB Handle
     ** DESTRUCTOR: sqlite3_blob
     **
     ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
     ** unconditionally.  Even if this routine returns an error code, the
     ** handle is still closed.)^
     **
     ** ^If the blob handle being closed was opened for read-write access, and if
     ** the database is in auto-commit mode and there are no other open read-write
     ** blob handles or active write statements, the current transaction is
     ** committed. ^If an error occurs while committing the transaction, an error
     ** code is returned and the transaction rolled back.
     **
     ** Calling this function with an argument that is not a NULL pointer or an
     ** open blob handle results in undefined behaviour. ^Calling this routine
     ** with a null pointer (such as would be returned by a failed call to
     ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
     ** is passed a valid open blob handle, the values returned by the
     ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *);
    
    /*
     ** CAPI3REF: Return The Size Of An Open BLOB
     ** METHOD: sqlite3_blob
     **
     ** ^Returns the size in bytes of the BLOB accessible via the
     ** successfully opened [BLOB handle] in its only argument.  ^The
     ** incremental blob I/O routines can only read or overwriting existing
     ** blob content; they cannot change the size of a blob.
     **
     ** This routine only works on a [BLOB handle] which has been created
     ** by a prior successful call to [sqlite3_blob_open()] and which has not
     ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
     ** to this routine results in undefined and probably undesirable behavior.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *);
    
    /*
     ** CAPI3REF: Read Data From A BLOB Incrementally
     ** METHOD: sqlite3_blob
     **
     ** ^(This function is used to read data from an open [BLOB handle] into a
     ** caller-supplied buffer. N bytes of data are copied into buffer Z
     ** from the open BLOB, starting at offset iOffset.)^
     **
     ** ^If offset iOffset is less than N bytes from the end of the BLOB,
     ** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
     ** less than zero, [SQLITE_ERROR] is returned and no data is read.
     ** ^The size of the blob (and hence the maximum value of N+iOffset)
     ** can be determined using the [sqlite3_blob_bytes()] interface.
     **
     ** ^An attempt to read from an expired [BLOB handle] fails with an
     ** error code of [SQLITE_ABORT].
     **
     ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
     ** Otherwise, an [error code] or an [extended error code] is returned.)^
     **
     ** This routine only works on a [BLOB handle] which has been created
     ** by a prior successful call to [sqlite3_blob_open()] and which has not
     ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
     ** to this routine results in undefined and probably undesirable behavior.
     **
     ** See also: [sqlite3_blob_write()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
    
    /*
     ** CAPI3REF: Write Data Into A BLOB Incrementally
     ** METHOD: sqlite3_blob
     **
     ** ^(This function is used to write data into an open [BLOB handle] from a
     ** caller-supplied buffer. N bytes of data are copied from the buffer Z
     ** into the open BLOB, starting at offset iOffset.)^
     **
     ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
     ** Otherwise, an  [error code] or an [extended error code] is returned.)^
     ** ^Unless SQLITE_MISUSE is returned, this function sets the
     ** [database connection] error code and message accessible via
     ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
     **
     ** ^If the [BLOB handle] passed as the first argument was not opened for
     ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
     ** this function returns [SQLITE_READONLY].
     **
     ** This function may only modify the contents of the BLOB; it is
     ** not possible to increase the size of a BLOB using this API.
     ** ^If offset iOffset is less than N bytes from the end of the BLOB,
     ** [SQLITE_ERROR] is returned and no data is written. The size of the
     ** BLOB (and hence the maximum value of N+iOffset) can be determined
     ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
     ** than zero [SQLITE_ERROR] is returned and no data is written.
     **
     ** ^An attempt to write to an expired [BLOB handle] fails with an
     ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
     ** before the [BLOB handle] expired are not rolled back by the
     ** expiration of the handle, though of course those changes might
     ** have been overwritten by the statement that expired the BLOB handle
     ** or by other independent statements.
     **
     ** This routine only works on a [BLOB handle] which has been created
     ** by a prior successful call to [sqlite3_blob_open()] and which has not
     ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
     ** to this routine results in undefined and probably undesirable behavior.
     **
     ** See also: [sqlite3_blob_read()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
    
    /*
     ** CAPI3REF: Virtual File System Objects
     **
     ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
     ** that SQLite uses to interact
     ** with the underlying operating system.  Most SQLite builds come with a
     ** single default VFS that is appropriate for the host computer.
     ** New VFSes can be registered and existing VFSes can be unregistered.
     ** The following interfaces are provided.
     **
     ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
     ** ^Names are case sensitive.
     ** ^Names are zero-terminated UTF-8 strings.
     ** ^If there is no match, a NULL pointer is returned.
     ** ^If zVfsName is NULL then the default VFS is returned.
     **
     ** ^New VFSes are registered with sqlite3_vfs_register().
     ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
     ** ^The same VFS can be registered multiple times without injury.
     ** ^To make an existing VFS into the default VFS, register it again
     ** with the makeDflt flag set.  If two different VFSes with the
     ** same name are registered, the behavior is undefined.  If a
     ** VFS is registered with a name that is NULL or an empty string,
     ** then the behavior is undefined.
     **
     ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
     ** ^(If the default VFS is unregistered, another VFS is chosen as
     ** the default.  The choice for the new VFS is arbitrary.)^
     */
    SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName);
    SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
    SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*);
    
    /*
     ** CAPI3REF: Mutexes
     **
     ** The SQLite core uses these routines for thread
     ** synchronization. Though they are intended for internal
     ** use by SQLite, code that links against SQLite is
     ** permitted to use any of these routines.
     **
     ** The SQLite source code contains multiple implementations
     ** of these mutex routines.  An appropriate implementation
     ** is selected automatically at compile-time.  The following
     ** implementations are available in the SQLite core:
     **
     ** <ul>
     ** <li>   SQLITE_MUTEX_PTHREADS
     ** <li>   SQLITE_MUTEX_W32
     ** <li>   SQLITE_MUTEX_NOOP
     ** </ul>
     **
     ** The SQLITE_MUTEX_NOOP implementation is a set of routines
     ** that does no real locking and is appropriate for use in
     ** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and
     ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
     ** and Windows.
     **
     ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
     ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
     ** implementation is included with the library. In this case the
     ** application must supply a custom mutex implementation using the
     ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
     ** before calling sqlite3_initialize() or any other public sqlite3_
     ** function that calls sqlite3_initialize().
     **
     ** ^The sqlite3_mutex_alloc() routine allocates a new
     ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
     ** routine returns NULL if it is unable to allocate the requested
     ** mutex.  The argument to sqlite3_mutex_alloc() must one of these
     ** integer constants:
     **
     ** <ul>
     ** <li>  SQLITE_MUTEX_FAST
     ** <li>  SQLITE_MUTEX_RECURSIVE
     ** <li>  SQLITE_MUTEX_STATIC_MASTER
     ** <li>  SQLITE_MUTEX_STATIC_MEM
     ** <li>  SQLITE_MUTEX_STATIC_OPEN
     ** <li>  SQLITE_MUTEX_STATIC_PRNG
     ** <li>  SQLITE_MUTEX_STATIC_LRU
     ** <li>  SQLITE_MUTEX_STATIC_PMEM
     ** <li>  SQLITE_MUTEX_STATIC_APP1
     ** <li>  SQLITE_MUTEX_STATIC_APP2
     ** <li>  SQLITE_MUTEX_STATIC_APP3
     ** <li>  SQLITE_MUTEX_STATIC_VFS1
     ** <li>  SQLITE_MUTEX_STATIC_VFS2
     ** <li>  SQLITE_MUTEX_STATIC_VFS3
     ** </ul>
     **
     ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
     ** cause sqlite3_mutex_alloc() to create
     ** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
     ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
     ** The mutex implementation does not need to make a distinction
     ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
     ** not want to.  SQLite will only request a recursive mutex in
     ** cases where it really needs one.  If a faster non-recursive mutex
     ** implementation is available on the host platform, the mutex subsystem
     ** might return such a mutex in response to SQLITE_MUTEX_FAST.
     **
     ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
     ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
     ** a pointer to a static preexisting mutex.  ^Nine static mutexes are
     ** used by the current version of SQLite.  Future versions of SQLite
     ** may add additional static mutexes.  Static mutexes are for internal
     ** use by SQLite only.  Applications that use SQLite mutexes should
     ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
     ** SQLITE_MUTEX_RECURSIVE.
     **
     ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
     ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
     ** returns a different mutex on every call.  ^For the static
     ** mutex types, the same mutex is returned on every call that has
     ** the same type number.
     **
     ** ^The sqlite3_mutex_free() routine deallocates a previously
     ** allocated dynamic mutex.  Attempting to deallocate a static
     ** mutex results in undefined behavior.
     **
     ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
     ** to enter a mutex.  ^If another thread is already within the mutex,
     ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
     ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
     ** upon successful entry.  ^(Mutexes created using
     ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
     ** In such cases, the
     ** mutex must be exited an equal number of times before another thread
     ** can enter.)^  If the same thread tries to enter any mutex other
     ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
     **
     ** ^(Some systems (for example, Windows 95) do not support the operation
     ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
     ** will always return SQLITE_BUSY. The SQLite core only ever uses
     ** sqlite3_mutex_try() as an optimization so this is acceptable
     ** behavior.)^
     **
     ** ^The sqlite3_mutex_leave() routine exits a mutex that was
     ** previously entered by the same thread.   The behavior
     ** is undefined if the mutex is not currently entered by the
     ** calling thread or is not currently allocated.
     **
     ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
     ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
     ** behave as no-ops.
     **
     ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
     */
    SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int);
    SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*);
    SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*);
    SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*);
    SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*);
    
    /*
     ** CAPI3REF: Mutex Methods Object
     **
     ** An instance of this structure defines the low-level routines
     ** used to allocate and use mutexes.
     **
     ** Usually, the default mutex implementations provided by SQLite are
     ** sufficient, however the application has the option of substituting a custom
     ** implementation for specialized deployments or systems for which SQLite
     ** does not provide a suitable implementation. In this case, the application
     ** creates and populates an instance of this structure to pass
     ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
     ** Additionally, an instance of this structure can be used as an
     ** output variable when querying the system for the current mutex
     ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
     **
     ** ^The xMutexInit method defined by this structure is invoked as
     ** part of system initialization by the sqlite3_initialize() function.
     ** ^The xMutexInit routine is called by SQLite exactly once for each
     ** effective call to [sqlite3_initialize()].
     **
     ** ^The xMutexEnd method defined by this structure is invoked as
     ** part of system shutdown by the sqlite3_shutdown() function. The
     ** implementation of this method is expected to release all outstanding
     ** resources obtained by the mutex methods implementation, especially
     ** those obtained by the xMutexInit method.  ^The xMutexEnd()
     ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
     **
     ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
     ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
     ** xMutexNotheld) implement the following interfaces (respectively):
     **
     ** <ul>
     **   <li>  [sqlite3_mutex_alloc()] </li>
     **   <li>  [sqlite3_mutex_free()] </li>
     **   <li>  [sqlite3_mutex_enter()] </li>
     **   <li>  [sqlite3_mutex_try()] </li>
     **   <li>  [sqlite3_mutex_leave()] </li>
     **   <li>  [sqlite3_mutex_held()] </li>
     **   <li>  [sqlite3_mutex_notheld()] </li>
     ** </ul>)^
     **
     ** The only difference is that the public sqlite3_XXX functions enumerated
     ** above silently ignore any invocations that pass a NULL pointer instead
     ** of a valid mutex handle. The implementations of the methods defined
     ** by this structure are not required to handle this case, the results
     ** of passing a NULL pointer instead of a valid mutex handle are undefined
     ** (i.e. it is acceptable to provide an implementation that segfaults if
     ** it is passed a NULL pointer).
     **
     ** The xMutexInit() method must be threadsafe.  It must be harmless to
     ** invoke xMutexInit() multiple times within the same process and without
     ** intervening calls to xMutexEnd().  Second and subsequent calls to
     ** xMutexInit() must be no-ops.
     **
     ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
     ** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
     ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
     ** memory allocation for a fast or recursive mutex.
     **
     ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
     ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
     ** If xMutexInit fails in any way, it is expected to clean up after itself
     ** prior to returning.
     */
    typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
    struct sqlite3_mutex_methods {
        int (*xMutexInit)(void);
        int (*xMutexEnd)(void);
        sqlite3_mutex *(*xMutexAlloc)(int);
        void (*xMutexFree)(sqlite3_mutex *);
        void (*xMutexEnter)(sqlite3_mutex *);
        int (*xMutexTry)(sqlite3_mutex *);
        void (*xMutexLeave)(sqlite3_mutex *);
        int (*xMutexHeld)(sqlite3_mutex *);
        int (*xMutexNotheld)(sqlite3_mutex *);
    };
    
    /*
     ** CAPI3REF: Mutex Verification Routines
     **
     ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
     ** are intended for use inside assert() statements.  The SQLite core
     ** never uses these routines except inside an assert() and applications
     ** are advised to follow the lead of the core.  The SQLite core only
     ** provides implementations for these routines when it is compiled
     ** with the SQLITE_DEBUG flag.  External mutex implementations
     ** are only required to provide these routines if SQLITE_DEBUG is
     ** defined and if NDEBUG is not defined.
     **
     ** These routines should return true if the mutex in their argument
     ** is held or not held, respectively, by the calling thread.
     **
     ** The implementation is not required to provide versions of these
     ** routines that actually work. If the implementation does not provide working
     ** versions of these routines, it should at least provide stubs that always
     ** return true so that one does not get spurious assertion failures.
     **
     ** If the argument to sqlite3_mutex_held() is a NULL pointer then
     ** the routine should return 1.   This seems counter-intuitive since
     ** clearly the mutex cannot be held if it does not exist.  But
     ** the reason the mutex does not exist is because the build is not
     ** using mutexes.  And we do not want the assert() containing the
     ** call to sqlite3_mutex_held() to fail, so a non-zero return is
     ** the appropriate thing to do.  The sqlite3_mutex_notheld()
     ** interface should also return 1 when given a NULL pointer.
     */
#ifndef NDEBUG
    SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*);
    SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*);
#endif
    
    /*
     ** CAPI3REF: Mutex Types
     **
     ** The [sqlite3_mutex_alloc()] interface takes a single argument
     ** which is one of these integer constants.
     **
     ** The set of static mutexes may change from one SQLite release to the
     ** next.  Applications that override the built-in mutex logic must be
     ** prepared to accommodate additional static mutexes.
     */
#define SQLITE_MUTEX_FAST             0
#define SQLITE_MUTEX_RECURSIVE        1
#define SQLITE_MUTEX_STATIC_MASTER    2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
#define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
#define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
#define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
#define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
#define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
#define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */
    
    /*
     ** CAPI3REF: Retrieve the mutex for a database connection
     ** METHOD: sqlite3
     **
     ** ^This interface returns a pointer the [sqlite3_mutex] object that
     ** serializes access to the [database connection] given in the argument
     ** when the [threading mode] is Serialized.
     ** ^If the [threading mode] is Single-thread or Multi-thread then this
     ** routine returns a NULL pointer.
     */
    SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*);
    
    /*
     ** CAPI3REF: Low-Level Control Of Database Files
     ** METHOD: sqlite3
     **
     ** ^The [sqlite3_file_control()] interface makes a direct call to the
     ** xFileControl method for the [sqlite3_io_methods] object associated
     ** with a particular database identified by the second argument. ^The
     ** name of the database is "main" for the main database or "temp" for the
     ** TEMP database, or the name that appears after the AS keyword for
     ** databases that are added using the [ATTACH] SQL command.
     ** ^A NULL pointer can be used in place of "main" to refer to the
     ** main database file.
     ** ^The third and fourth parameters to this routine
     ** are passed directly through to the second and third parameters of
     ** the xFileControl method.  ^The return value of the xFileControl
     ** method becomes the return value of this routine.
     **
     ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
     ** a pointer to the underlying [sqlite3_file] object to be written into
     ** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
     ** case is a short-circuit path which does not actually invoke the
     ** underlying sqlite3_io_methods.xFileControl method.
     **
     ** ^If the second parameter (zDbName) does not match the name of any
     ** open database file, then SQLITE_ERROR is returned.  ^This error
     ** code is not remembered and will not be recalled by [sqlite3_errcode()]
     ** or [sqlite3_errmsg()].  The underlying xFileControl method might
     ** also return SQLITE_ERROR.  There is no way to distinguish between
     ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
     ** xFileControl method.
     **
     ** See also: [SQLITE_FCNTL_LOCKSTATE]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
    
    /*
     ** CAPI3REF: Testing Interface
     **
     ** ^The sqlite3_test_control() interface is used to read out internal
     ** state of SQLite and to inject faults into SQLite for testing
     ** purposes.  ^The first parameter is an operation code that determines
     ** the number, meaning, and operation of all subsequent parameters.
     **
     ** This interface is not for use by applications.  It exists solely
     ** for verifying the correct operation of the SQLite library.  Depending
     ** on how the SQLite library is compiled, this interface might not exist.
     **
     ** The details of the operation codes, their meanings, the parameters
     ** they take, and what they do are all subject to change without notice.
     ** Unlike most of the SQLite API, this function is not guaranteed to
     ** operate consistently from one release to the next.
     */
    SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...);
    
    /*
     ** CAPI3REF: Testing Interface Operation Codes
     **
     ** These constants are the valid operation code parameters used
     ** as the first argument to [sqlite3_test_control()].
     **
     ** These parameters and their meanings are subject to change
     ** without notice.  These values are for testing purposes only.
     ** Applications should not use any of these parameters or the
     ** [sqlite3_test_control()] interface.
     */
#define SQLITE_TESTCTRL_FIRST                    5
#define SQLITE_TESTCTRL_PRNG_SAVE                5
#define SQLITE_TESTCTRL_PRNG_RESTORE             6
#define SQLITE_TESTCTRL_PRNG_RESET               7
#define SQLITE_TESTCTRL_BITVEC_TEST              8
#define SQLITE_TESTCTRL_FAULT_INSTALL            9
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
#define SQLITE_TESTCTRL_PENDING_BYTE            11
#define SQLITE_TESTCTRL_ASSERT                  12
#define SQLITE_TESTCTRL_ALWAYS                  13
#define SQLITE_TESTCTRL_RESERVE                 14
#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
#define SQLITE_TESTCTRL_ISKEYWORD               16
#define SQLITE_TESTCTRL_SCRATCHMALLOC           17
#define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
#define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
#define SQLITE_TESTCTRL_VDBE_COVERAGE           21
#define SQLITE_TESTCTRL_BYTEORDER               22
#define SQLITE_TESTCTRL_ISINIT                  23
#define SQLITE_TESTCTRL_SORTER_MMAP             24
#define SQLITE_TESTCTRL_IMPOSTER                25
#define SQLITE_TESTCTRL_LAST                    25
    
    /*
     ** CAPI3REF: SQLite Runtime Status
     **
     ** ^These interfaces are used to retrieve runtime status information
     ** about the performance of SQLite, and optionally to reset various
     ** highwater marks.  ^The first argument is an integer code for
     ** the specific parameter to measure.  ^(Recognized integer codes
     ** are of the form [status parameters | SQLITE_STATUS_...].)^
     ** ^The current value of the parameter is returned into *pCurrent.
     ** ^The highest recorded value is returned in *pHighwater.  ^If the
     ** resetFlag is true, then the highest record value is reset after
     ** *pHighwater is written.  ^(Some parameters do not record the highest
     ** value.  For those parameters
     ** nothing is written into *pHighwater and the resetFlag is ignored.)^
     ** ^(Other parameters record only the highwater mark and not the current
     ** value.  For these latter parameters nothing is written into *pCurrent.)^
     **
     ** ^The sqlite3_status() and sqlite3_status64() routines return
     ** SQLITE_OK on success and a non-zero [error code] on failure.
     **
     ** If either the current value or the highwater mark is too large to
     ** be represented by a 32-bit integer, then the values returned by
     ** sqlite3_status() are undefined.
     **
     ** See also: [sqlite3_db_status()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
    SQLITE_API int SQLITE_STDCALL sqlite3_status64(
                                                   int op,
                                                   sqlite3_int64 *pCurrent,
                                                   sqlite3_int64 *pHighwater,
                                                   int resetFlag
                                                   );
    
    
    /*
     ** CAPI3REF: Status Parameters
     ** KEYWORDS: {status parameters}
     **
     ** These integer constants designate various run-time status parameters
     ** that can be returned by [sqlite3_status()].
     **
     ** <dl>
     ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
     ** <dd>This parameter is the current amount of memory checked out
     ** using [sqlite3_malloc()], either directly or indirectly.  The
     ** figure includes calls made to [sqlite3_malloc()] by the application
     ** and internal memory usage by the SQLite library.  Scratch memory
     ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
     ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
     ** this parameter.  The amount returned is the sum of the allocation
     ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
     **
     ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
     ** <dd>This parameter records the largest memory allocation request
     ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
     ** internal equivalents).  Only the value returned in the
     ** *pHighwater parameter to [sqlite3_status()] is of interest.
     ** The value written into the *pCurrent parameter is undefined.</dd>)^
     **
     ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
     ** <dd>This parameter records the number of separate memory allocations
     ** currently checked out.</dd>)^
     **
     ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
     ** <dd>This parameter returns the number of pages used out of the
     ** [pagecache memory allocator] that was configured using
     ** [SQLITE_CONFIG_PAGECACHE].  The
     ** value returned is in pages, not in bytes.</dd>)^
     **
     ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
     ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
     ** <dd>This parameter returns the number of bytes of page cache
     ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
     ** buffer and where forced to overflow to [sqlite3_malloc()].  The
     ** returned value includes allocations that overflowed because they
     ** where too large (they were larger than the "sz" parameter to
     ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
     ** no space was left in the page cache.</dd>)^
     **
     ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
     ** <dd>This parameter records the largest memory allocation request
     ** handed to [pagecache memory allocator].  Only the value returned in the
     ** *pHighwater parameter to [sqlite3_status()] is of interest.
     ** The value written into the *pCurrent parameter is undefined.</dd>)^
     **
     ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
     ** <dd>This parameter returns the number of allocations used out of the
     ** [scratch memory allocator] configured using
     ** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
     ** in bytes.  Since a single thread may only have one scratch allocation
     ** outstanding at time, this parameter also reports the number of threads
     ** using scratch memory at the same time.</dd>)^
     **
     ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
     ** <dd>This parameter returns the number of bytes of scratch memory
     ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
     ** buffer and where forced to overflow to [sqlite3_malloc()].  The values
     ** returned include overflows because the requested allocation was too
     ** larger (that is, because the requested allocation was larger than the
     ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
     ** slots were available.
     ** </dd>)^
     **
     ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
     ** <dd>This parameter records the largest memory allocation request
     ** handed to [scratch memory allocator].  Only the value returned in the
     ** *pHighwater parameter to [sqlite3_status()] is of interest.
     ** The value written into the *pCurrent parameter is undefined.</dd>)^
     **
     ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
     ** <dd>The *pHighwater parameter records the deepest parser stack.
     ** The *pCurrent value is undefined.  The *pHighwater value is only
     ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
     ** </dl>
     **
     ** New status parameters may be added from time to time.
     */
#define SQLITE_STATUS_MEMORY_USED          0
#define SQLITE_STATUS_PAGECACHE_USED       1
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
#define SQLITE_STATUS_SCRATCH_USED         3
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
#define SQLITE_STATUS_MALLOC_SIZE          5
#define SQLITE_STATUS_PARSER_STACK         6
#define SQLITE_STATUS_PAGECACHE_SIZE       7
#define SQLITE_STATUS_SCRATCH_SIZE         8
#define SQLITE_STATUS_MALLOC_COUNT         9
    
    /*
     ** CAPI3REF: Database Connection Status
     ** METHOD: sqlite3
     **
     ** ^This interface is used to retrieve runtime status information
     ** about a single [database connection].  ^The first argument is the
     ** database connection object to be interrogated.  ^The second argument
     ** is an integer constant, taken from the set of
     ** [SQLITE_DBSTATUS options], that
     ** determines the parameter to interrogate.  The set of
     ** [SQLITE_DBSTATUS options] is likely
     ** to grow in future releases of SQLite.
     **
     ** ^The current value of the requested parameter is written into *pCur
     ** and the highest instantaneous value is written into *pHiwtr.  ^If
     ** the resetFlg is true, then the highest instantaneous value is
     ** reset back down to the current value.
     **
     ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
     ** non-zero [error code] on failure.
     **
     ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
    
    /*
     ** CAPI3REF: Status Parameters for database connections
     ** KEYWORDS: {SQLITE_DBSTATUS options}
     **
     ** These constants are the available integer "verbs" that can be passed as
     ** the second argument to the [sqlite3_db_status()] interface.
     **
     ** New verbs may be added in future releases of SQLite. Existing verbs
     ** might be discontinued. Applications should check the return code from
     ** [sqlite3_db_status()] to make sure that the call worked.
     ** The [sqlite3_db_status()] interface will return a non-zero error code
     ** if a discontinued or unsupported verb is invoked.
     **
     ** <dl>
     ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
     ** <dd>This parameter returns the number of lookaside memory slots currently
     ** checked out.</dd>)^
     **
     ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
     ** <dd>This parameter returns the number malloc attempts that were
     ** satisfied using lookaside memory. Only the high-water value is meaningful;
     ** the current value is always zero.)^
     **
     ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
     ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
     ** <dd>This parameter returns the number malloc attempts that might have
     ** been satisfied using lookaside memory but failed due to the amount of
     ** memory requested being larger than the lookaside slot size.
     ** Only the high-water value is meaningful;
     ** the current value is always zero.)^
     **
     ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
     ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
     ** <dd>This parameter returns the number malloc attempts that might have
     ** been satisfied using lookaside memory but failed due to all lookaside
     ** memory already being in use.
     ** Only the high-water value is meaningful;
     ** the current value is always zero.)^
     **
     ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
     ** <dd>This parameter returns the approximate number of bytes of heap
     ** memory used by all pager caches associated with the database connection.)^
     ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
     **
     ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
     ** <dd>This parameter returns the approximate number of bytes of heap
     ** memory used to store the schema for all databases associated
     ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
     ** ^The full amount of memory used by the schemas is reported, even if the
     ** schema memory is shared with other database connections due to
     ** [shared cache mode] being enabled.
     ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
     **
     ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
     ** <dd>This parameter returns the approximate number of bytes of heap
     ** and lookaside memory used by all prepared statements associated with
     ** the database connection.)^
     ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
     ** </dd>
     **
     ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
     ** <dd>This parameter returns the number of pager cache hits that have
     ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
     ** is always 0.
     ** </dd>
     **
     ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
     ** <dd>This parameter returns the number of pager cache misses that have
     ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
     ** is always 0.
     ** </dd>
     **
     ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
     ** <dd>This parameter returns the number of dirty cache entries that have
     ** been written to disk. Specifically, the number of pages written to the
     ** wal file in wal mode databases, or the number of pages written to the
     ** database file in rollback mode databases. Any pages written as part of
     ** transaction rollback or database recovery operations are not included.
     ** If an IO or other error occurs while writing a page to disk, the effect
     ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
     ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
     ** </dd>
     **
     ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
     ** <dd>This parameter returns zero for the current value if and only if
     ** all foreign key constraints (deferred or immediate) have been
     ** resolved.)^  ^The highwater mark is always 0.
     ** </dd>
     ** </dl>
     */
#define SQLITE_DBSTATUS_LOOKASIDE_USED       0
#define SQLITE_DBSTATUS_CACHE_USED           1
#define SQLITE_DBSTATUS_SCHEMA_USED          2
#define SQLITE_DBSTATUS_STMT_USED            3
#define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
#define SQLITE_DBSTATUS_CACHE_HIT            7
#define SQLITE_DBSTATUS_CACHE_MISS           8
#define SQLITE_DBSTATUS_CACHE_WRITE          9
#define SQLITE_DBSTATUS_DEFERRED_FKS        10
#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
    
    
    /*
     ** CAPI3REF: Prepared Statement Status
     ** METHOD: sqlite3_stmt
     **
     ** ^(Each prepared statement maintains various
     ** [SQLITE_STMTSTATUS counters] that measure the number
     ** of times it has performed specific operations.)^  These counters can
     ** be used to monitor the performance characteristics of the prepared
     ** statements.  For example, if the number of table steps greatly exceeds
     ** the number of table searches or result rows, that would tend to indicate
     ** that the prepared statement is using a full table scan rather than
     ** an index.
     **
     ** ^(This interface is used to retrieve and reset counter values from
     ** a [prepared statement].  The first argument is the prepared statement
     ** object to be interrogated.  The second argument
     ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
     ** to be interrogated.)^
     ** ^The current value of the requested counter is returned.
     ** ^If the resetFlg is true, then the counter is reset to zero after this
     ** interface call returns.
     **
     ** See also: [sqlite3_status()] and [sqlite3_db_status()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
    
    /*
     ** CAPI3REF: Status Parameters for prepared statements
     ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
     **
     ** These preprocessor macros define integer codes that name counter
     ** values associated with the [sqlite3_stmt_status()] interface.
     ** The meanings of the various counters are as follows:
     **
     ** <dl>
     ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
     ** <dd>^This is the number of times that SQLite has stepped forward in
     ** a table as part of a full table scan.  Large numbers for this counter
     ** may indicate opportunities for performance improvement through
     ** careful use of indices.</dd>
     **
     ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
     ** <dd>^This is the number of sort operations that have occurred.
     ** A non-zero value in this counter may indicate an opportunity to
     ** improvement performance through careful use of indices.</dd>
     **
     ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
     ** <dd>^This is the number of rows inserted into transient indices that
     ** were created automatically in order to help joins run faster.
     ** A non-zero value in this counter may indicate an opportunity to
     ** improvement performance by adding permanent indices that do not
     ** need to be reinitialized each time the statement is run.</dd>
     **
     ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
     ** <dd>^This is the number of virtual machine operations executed
     ** by the prepared statement if that number is less than or equal
     ** to 2147483647.  The number of virtual machine operations can be
     ** used as a proxy for the total work done by the prepared statement.
     ** If the number of virtual machine operations exceeds 2147483647
     ** then the value returned by this statement status code is undefined.
     ** </dd>
     ** </dl>
     */
#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
#define SQLITE_STMTSTATUS_SORT              2
#define SQLITE_STMTSTATUS_AUTOINDEX         3
#define SQLITE_STMTSTATUS_VM_STEP           4
    
    /*
     ** CAPI3REF: Custom Page Cache Object
     **
     ** The sqlite3_pcache type is opaque.  It is implemented by
     ** the pluggable module.  The SQLite core has no knowledge of
     ** its size or internal structure and never deals with the
     ** sqlite3_pcache object except by holding and passing pointers
     ** to the object.
     **
     ** See [sqlite3_pcache_methods2] for additional information.
     */
    typedef struct sqlite3_pcache sqlite3_pcache;
    
    /*
     ** CAPI3REF: Custom Page Cache Object
     **
     ** The sqlite3_pcache_page object represents a single page in the
     ** page cache.  The page cache will allocate instances of this
     ** object.  Various methods of the page cache use pointers to instances
     ** of this object as parameters or as their return value.
     **
     ** See [sqlite3_pcache_methods2] for additional information.
     */
    typedef struct sqlite3_pcache_page sqlite3_pcache_page;
    struct sqlite3_pcache_page {
        void *pBuf;        /* The content of the page */
        void *pExtra;      /* Extra information associated with the page */
    };
    
    /*
     ** CAPI3REF: Application Defined Page Cache.
     ** KEYWORDS: {page cache}
     **
     ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
     ** register an alternative page cache implementation by passing in an
     ** instance of the sqlite3_pcache_methods2 structure.)^
     ** In many applications, most of the heap memory allocated by
     ** SQLite is used for the page cache.
     ** By implementing a
     ** custom page cache using this API, an application can better control
     ** the amount of memory consumed by SQLite, the way in which
     ** that memory is allocated and released, and the policies used to
     ** determine exactly which parts of a database file are cached and for
     ** how long.
     **
     ** The alternative page cache mechanism is an
     ** extreme measure that is only needed by the most demanding applications.
     ** The built-in page cache is recommended for most uses.
     **
     ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
     ** internal buffer by SQLite within the call to [sqlite3_config].  Hence
     ** the application may discard the parameter after the call to
     ** [sqlite3_config()] returns.)^
     **
     ** [[the xInit() page cache method]]
     ** ^(The xInit() method is called once for each effective
     ** call to [sqlite3_initialize()])^
     ** (usually only once during the lifetime of the process). ^(The xInit()
     ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
     ** The intent of the xInit() method is to set up global data structures
     ** required by the custom page cache implementation.
     ** ^(If the xInit() method is NULL, then the
     ** built-in default page cache is used instead of the application defined
     ** page cache.)^
     **
     ** [[the xShutdown() page cache method]]
     ** ^The xShutdown() method is called by [sqlite3_shutdown()].
     ** It can be used to clean up
     ** any outstanding resources before process shutdown, if required.
     ** ^The xShutdown() method may be NULL.
     **
     ** ^SQLite automatically serializes calls to the xInit method,
     ** so the xInit method need not be threadsafe.  ^The
     ** xShutdown method is only called from [sqlite3_shutdown()] so it does
     ** not need to be threadsafe either.  All other methods must be threadsafe
     ** in multithreaded applications.
     **
     ** ^SQLite will never invoke xInit() more than once without an intervening
     ** call to xShutdown().
     **
     ** [[the xCreate() page cache methods]]
     ** ^SQLite invokes the xCreate() method to construct a new cache instance.
     ** SQLite will typically create one cache instance for each open database file,
     ** though this is not guaranteed. ^The
     ** first parameter, szPage, is the size in bytes of the pages that must
     ** be allocated by the cache.  ^szPage will always a power of two.  ^The
     ** second parameter szExtra is a number of bytes of extra storage
     ** associated with each page cache entry.  ^The szExtra parameter will
     ** a number less than 250.  SQLite will use the
     ** extra szExtra bytes on each page to store metadata about the underlying
     ** database page on disk.  The value passed into szExtra depends
     ** on the SQLite version, the target platform, and how SQLite was compiled.
     ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
     ** created will be used to cache database pages of a file stored on disk, or
     ** false if it is used for an in-memory database. The cache implementation
     ** does not have to do anything special based with the value of bPurgeable;
     ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
     ** never invoke xUnpin() except to deliberately delete a page.
     ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
     ** false will always have the "discard" flag set to true.
     ** ^Hence, a cache created with bPurgeable false will
     ** never contain any unpinned pages.
     **
     ** [[the xCachesize() page cache method]]
     ** ^(The xCachesize() method may be called at any time by SQLite to set the
     ** suggested maximum cache-size (number of pages stored by) the cache
     ** instance passed as the first argument. This is the value configured using
     ** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
     ** parameter, the implementation is not required to do anything with this
     ** value; it is advisory only.
     **
     ** [[the xPagecount() page cache methods]]
     ** The xPagecount() method must return the number of pages currently
     ** stored in the cache, both pinned and unpinned.
     **
     ** [[the xFetch() page cache methods]]
     ** The xFetch() method locates a page in the cache and returns a pointer to
     ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
     ** The pBuf element of the returned sqlite3_pcache_page object will be a
     ** pointer to a buffer of szPage bytes used to store the content of a
     ** single database page.  The pExtra element of sqlite3_pcache_page will be
     ** a pointer to the szExtra bytes of extra storage that SQLite has requested
     ** for each entry in the page cache.
     **
     ** The page to be fetched is determined by the key. ^The minimum key value
     ** is 1.  After it has been retrieved using xFetch, the page is considered
     ** to be "pinned".
     **
     ** If the requested page is already in the page cache, then the page cache
     ** implementation must return a pointer to the page buffer with its content
     ** intact.  If the requested page is not already in the cache, then the
     ** cache implementation should use the value of the createFlag
     ** parameter to help it determined what action to take:
     **
     ** <table border=1 width=85% align=center>
     ** <tr><th> createFlag <th> Behavior when page is not already in cache
     ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
     ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
     **                 Otherwise return NULL.
     ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
     **                 NULL if allocating a new page is effectively impossible.
     ** </table>
     **
     ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
     ** will only use a createFlag of 2 after a prior call with a createFlag of 1
     ** failed.)^  In between the to xFetch() calls, SQLite may
     ** attempt to unpin one or more cache pages by spilling the content of
     ** pinned pages to disk and synching the operating system disk cache.
     **
     ** [[the xUnpin() page cache method]]
     ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
     ** as its second argument.  If the third parameter, discard, is non-zero,
     ** then the page must be evicted from the cache.
     ** ^If the discard parameter is
     ** zero, then the page may be discarded or retained at the discretion of
     ** page cache implementation. ^The page cache implementation
     ** may choose to evict unpinned pages at any time.
     **
     ** The cache must not perform any reference counting. A single
     ** call to xUnpin() unpins the page regardless of the number of prior calls
     ** to xFetch().
     **
     ** [[the xRekey() page cache methods]]
     ** The xRekey() method is used to change the key value associated with the
     ** page passed as the second argument. If the cache
     ** previously contains an entry associated with newKey, it must be
     ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
     ** to be pinned.
     **
     ** When SQLite calls the xTruncate() method, the cache must discard all
     ** existing cache entries with page numbers (keys) greater than or equal
     ** to the value of the iLimit parameter passed to xTruncate(). If any
     ** of these pages are pinned, they are implicitly unpinned, meaning that
     ** they can be safely discarded.
     **
     ** [[the xDestroy() page cache method]]
     ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
     ** All resources associated with the specified cache should be freed. ^After
     ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
     ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
     ** functions.
     **
     ** [[the xShrink() page cache method]]
     ** ^SQLite invokes the xShrink() method when it wants the page cache to
     ** free up as much of heap memory as possible.  The page cache implementation
     ** is not obligated to free any memory, but well-behaved implementations should
     ** do their best.
     */
    typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
    struct sqlite3_pcache_methods2 {
        int iVersion;
        void *pArg;
        int (*xInit)(void*);
        void (*xShutdown)(void*);
        sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
        void (*xCachesize)(sqlite3_pcache*, int nCachesize);
        int (*xPagecount)(sqlite3_pcache*);
        sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
        void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
        void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
                       unsigned oldKey, unsigned newKey);
        void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
        void (*xDestroy)(sqlite3_pcache*);
        void (*xShrink)(sqlite3_pcache*);
    };
    
    /*
     ** This is the obsolete pcache_methods object that has now been replaced
     ** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
     ** retained in the header file for backwards compatibility only.
     */
    typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
    struct sqlite3_pcache_methods {
        void *pArg;
        int (*xInit)(void*);
        void (*xShutdown)(void*);
        sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
        void (*xCachesize)(sqlite3_pcache*, int nCachesize);
        int (*xPagecount)(sqlite3_pcache*);
        void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
        void (*xUnpin)(sqlite3_pcache*, void*, int discard);
        void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
        void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
        void (*xDestroy)(sqlite3_pcache*);
    };
    
    
    /*
     ** CAPI3REF: Online Backup Object
     **
     ** The sqlite3_backup object records state information about an ongoing
     ** online backup operation.  ^The sqlite3_backup object is created by
     ** a call to [sqlite3_backup_init()] and is destroyed by a call to
     ** [sqlite3_backup_finish()].
     **
     ** See Also: [Using the SQLite Online Backup API]
     */
    typedef struct sqlite3_backup sqlite3_backup;
    
    /*
     ** CAPI3REF: Online Backup API.
     **
     ** The backup API copies the content of one database into another.
     ** It is useful either for creating backups of databases or
     ** for copying in-memory databases to or from persistent files.
     **
     ** See Also: [Using the SQLite Online Backup API]
     **
     ** ^SQLite holds a write transaction open on the destination database file
     ** for the duration of the backup operation.
     ** ^The source database is read-locked only while it is being read;
     ** it is not locked continuously for the entire backup operation.
     ** ^Thus, the backup may be performed on a live source database without
     ** preventing other database connections from
     ** reading or writing to the source database while the backup is underway.
     **
     ** ^(To perform a backup operation:
     **   <ol>
     **     <li><b>sqlite3_backup_init()</b> is called once to initialize the
     **         backup,
     **     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
     **         the data between the two databases, and finally
     **     <li><b>sqlite3_backup_finish()</b> is called to release all resources
     **         associated with the backup operation.
     **   </ol>)^
     ** There should be exactly one call to sqlite3_backup_finish() for each
     ** successful call to sqlite3_backup_init().
     **
     ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
     **
     ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
     ** [database connection] associated with the destination database
     ** and the database name, respectively.
     ** ^The database name is "main" for the main database, "temp" for the
     ** temporary database, or the name specified after the AS keyword in
     ** an [ATTACH] statement for an attached database.
     ** ^The S and M arguments passed to
     ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
     ** and database name of the source database, respectively.
     ** ^The source and destination [database connections] (parameters S and D)
     ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
     ** an error.
     **
     ** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if
     ** there is already a read or read-write transaction open on the
     ** destination database.
     **
     ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
     ** returned and an error code and error message are stored in the
     ** destination [database connection] D.
     ** ^The error code and message for the failed call to sqlite3_backup_init()
     ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
     ** [sqlite3_errmsg16()] functions.
     ** ^A successful call to sqlite3_backup_init() returns a pointer to an
     ** [sqlite3_backup] object.
     ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
     ** sqlite3_backup_finish() functions to perform the specified backup
     ** operation.
     **
     ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
     **
     ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
     ** the source and destination databases specified by [sqlite3_backup] object B.
     ** ^If N is negative, all remaining source pages are copied.
     ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
     ** are still more pages to be copied, then the function returns [SQLITE_OK].
     ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
     ** from source to destination, then it returns [SQLITE_DONE].
     ** ^If an error occurs while running sqlite3_backup_step(B,N),
     ** then an [error code] is returned. ^As well as [SQLITE_OK] and
     ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
     ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
     ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
     **
     ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
     ** <ol>
     ** <li> the destination database was opened read-only, or
     ** <li> the destination database is using write-ahead-log journaling
     ** and the destination and source page sizes differ, or
     ** <li> the destination database is an in-memory database and the
     ** destination and source page sizes differ.
     ** </ol>)^
     **
     ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
     ** the [sqlite3_busy_handler | busy-handler function]
     ** is invoked (if one is specified). ^If the
     ** busy-handler returns non-zero before the lock is available, then
     ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
     ** sqlite3_backup_step() can be retried later. ^If the source
     ** [database connection]
     ** is being used to write to the source database when sqlite3_backup_step()
     ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
     ** case the call to sqlite3_backup_step() can be retried later on. ^(If
     ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
     ** [SQLITE_READONLY] is returned, then
     ** there is no point in retrying the call to sqlite3_backup_step(). These
     ** errors are considered fatal.)^  The application must accept
     ** that the backup operation has failed and pass the backup operation handle
     ** to the sqlite3_backup_finish() to release associated resources.
     **
     ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
     ** on the destination file. ^The exclusive lock is not released until either
     ** sqlite3_backup_finish() is called or the backup operation is complete
     ** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
     ** sqlite3_backup_step() obtains a [shared lock] on the source database that
     ** lasts for the duration of the sqlite3_backup_step() call.
     ** ^Because the source database is not locked between calls to
     ** sqlite3_backup_step(), the source database may be modified mid-way
     ** through the backup process.  ^If the source database is modified by an
     ** external process or via a database connection other than the one being
     ** used by the backup operation, then the backup will be automatically
     ** restarted by the next call to sqlite3_backup_step(). ^If the source
     ** database is modified by the using the same database connection as is used
     ** by the backup operation, then the backup database is automatically
     ** updated at the same time.
     **
     ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
     **
     ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
     ** application wishes to abandon the backup operation, the application
     ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
     ** ^The sqlite3_backup_finish() interfaces releases all
     ** resources associated with the [sqlite3_backup] object.
     ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
     ** active write-transaction on the destination database is rolled back.
     ** The [sqlite3_backup] object is invalid
     ** and may not be used following a call to sqlite3_backup_finish().
     **
     ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
     ** sqlite3_backup_step() errors occurred, regardless or whether or not
     ** sqlite3_backup_step() completed.
     ** ^If an out-of-memory condition or IO error occurred during any prior
     ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
     ** sqlite3_backup_finish() returns the corresponding [error code].
     **
     ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
     ** is not a permanent error and does not affect the return value of
     ** sqlite3_backup_finish().
     **
     ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
     ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
     **
     ** ^The sqlite3_backup_remaining() routine returns the number of pages still
     ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
     ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
     ** in the source database at the conclusion of the most recent
     ** sqlite3_backup_step().
     ** ^(The values returned by these functions are only updated by
     ** sqlite3_backup_step(). If the source database is modified in a way that
     ** changes the size of the source database or the number of pages remaining,
     ** those changes are not reflected in the output of sqlite3_backup_pagecount()
     ** and sqlite3_backup_remaining() until after the next
     ** sqlite3_backup_step().)^
     **
     ** <b>Concurrent Usage of Database Handles</b>
     **
     ** ^The source [database connection] may be used by the application for other
     ** purposes while a backup operation is underway or being initialized.
     ** ^If SQLite is compiled and configured to support threadsafe database
     ** connections, then the source database connection may be used concurrently
     ** from within other threads.
     **
     ** However, the application must guarantee that the destination
     ** [database connection] is not passed to any other API (by any thread) after
     ** sqlite3_backup_init() is called and before the corresponding call to
     ** sqlite3_backup_finish().  SQLite does not currently check to see
     ** if the application incorrectly accesses the destination [database connection]
     ** and so no error code is reported, but the operations may malfunction
     ** nevertheless.  Use of the destination database connection while a
     ** backup is in progress might also also cause a mutex deadlock.
     **
     ** If running in [shared cache mode], the application must
     ** guarantee that the shared cache used by the destination database
     ** is not accessed while the backup is running. In practice this means
     ** that the application must guarantee that the disk file being
     ** backed up to is not accessed by any connection within the process,
     ** not just the specific connection that was passed to sqlite3_backup_init().
     **
     ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
     ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
     ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
     ** APIs are not strictly speaking threadsafe. If they are invoked at the
     ** same time as another thread is invoking sqlite3_backup_step() it is
     ** possible that they return invalid values.
     */
    SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init(
                                                                  sqlite3 *pDest,                        /* Destination database handle */
                                                                  const char *zDestName,                 /* Destination database name */
                                                                  sqlite3 *pSource,                      /* Source database handle */
                                                                  const char *zSourceName                /* Source database name */
    );
    SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage);
    SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p);
    SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p);
    SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p);
    
    /*
     ** CAPI3REF: Unlock Notification
     ** METHOD: sqlite3
     **
     ** ^When running in shared-cache mode, a database operation may fail with
     ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
     ** individual tables within the shared-cache cannot be obtained. See
     ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
     ** ^This API may be used to register a callback that SQLite will invoke
     ** when the connection currently holding the required lock relinquishes it.
     ** ^This API is only available if the library was compiled with the
     ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
     **
     ** See Also: [Using the SQLite Unlock Notification Feature].
     **
     ** ^Shared-cache locks are released when a database connection concludes
     ** its current transaction, either by committing it or rolling it back.
     **
     ** ^When a connection (known as the blocked connection) fails to obtain a
     ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
     ** identity of the database connection (the blocking connection) that
     ** has locked the required resource is stored internally. ^After an
     ** application receives an SQLITE_LOCKED error, it may call the
     ** sqlite3_unlock_notify() method with the blocked connection handle as
     ** the first argument to register for a callback that will be invoked
     ** when the blocking connections current transaction is concluded. ^The
     ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
     ** call that concludes the blocking connections transaction.
     **
     ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
     ** there is a chance that the blocking connection will have already
     ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
     ** If this happens, then the specified callback is invoked immediately,
     ** from within the call to sqlite3_unlock_notify().)^
     **
     ** ^If the blocked connection is attempting to obtain a write-lock on a
     ** shared-cache table, and more than one other connection currently holds
     ** a read-lock on the same table, then SQLite arbitrarily selects one of
     ** the other connections to use as the blocking connection.
     **
     ** ^(There may be at most one unlock-notify callback registered by a
     ** blocked connection. If sqlite3_unlock_notify() is called when the
     ** blocked connection already has a registered unlock-notify callback,
     ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
     ** called with a NULL pointer as its second argument, then any existing
     ** unlock-notify callback is canceled. ^The blocked connections
     ** unlock-notify callback may also be canceled by closing the blocked
     ** connection using [sqlite3_close()].
     **
     ** The unlock-notify callback is not reentrant. If an application invokes
     ** any sqlite3_xxx API functions from within an unlock-notify callback, a
     ** crash or deadlock may be the result.
     **
     ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
     ** returns SQLITE_OK.
     **
     ** <b>Callback Invocation Details</b>
     **
     ** When an unlock-notify callback is registered, the application provides a
     ** single void* pointer that is passed to the callback when it is invoked.
     ** However, the signature of the callback function allows SQLite to pass
     ** it an array of void* context pointers. The first argument passed to
     ** an unlock-notify callback is a pointer to an array of void* pointers,
     ** and the second is the number of entries in the array.
     **
     ** When a blocking connections transaction is concluded, there may be
     ** more than one blocked connection that has registered for an unlock-notify
     ** callback. ^If two or more such blocked connections have specified the
     ** same callback function, then instead of invoking the callback function
     ** multiple times, it is invoked once with the set of void* context pointers
     ** specified by the blocked connections bundled together into an array.
     ** This gives the application an opportunity to prioritize any actions
     ** related to the set of unblocked database connections.
     **
     ** <b>Deadlock Detection</b>
     **
     ** Assuming that after registering for an unlock-notify callback a
     ** database waits for the callback to be issued before taking any further
     ** action (a reasonable assumption), then using this API may cause the
     ** application to deadlock. For example, if connection X is waiting for
     ** connection Y's transaction to be concluded, and similarly connection
     ** Y is waiting on connection X's transaction, then neither connection
     ** will proceed and the system may remain deadlocked indefinitely.
     **
     ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
     ** detection. ^If a given call to sqlite3_unlock_notify() would put the
     ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
     ** unlock-notify callback is registered. The system is said to be in
     ** a deadlocked state if connection A has registered for an unlock-notify
     ** callback on the conclusion of connection B's transaction, and connection
     ** B has itself registered for an unlock-notify callback when connection
     ** A's transaction is concluded. ^Indirect deadlock is also detected, so
     ** the system is also considered to be deadlocked if connection B has
     ** registered for an unlock-notify callback on the conclusion of connection
     ** C's transaction, where connection C is waiting on connection A. ^Any
     ** number of levels of indirection are allowed.
     **
     ** <b>The "DROP TABLE" Exception</b>
     **
     ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
     ** always appropriate to call sqlite3_unlock_notify(). There is however,
     ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
     ** SQLite checks if there are any currently executing SELECT statements
     ** that belong to the same connection. If there are, SQLITE_LOCKED is
     ** returned. In this case there is no "blocking connection", so invoking
     ** sqlite3_unlock_notify() results in the unlock-notify callback being
     ** invoked immediately. If the application then re-attempts the "DROP TABLE"
     ** or "DROP INDEX" query, an infinite loop might be the result.
     **
     ** One way around this problem is to check the extended error code returned
     ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
     ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
     ** the special "DROP TABLE/INDEX" case, the extended error code is just
     ** SQLITE_LOCKED.)^
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify(
                                                        sqlite3 *pBlocked,                          /* Waiting connection */
                                                        void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
                                                        void *pNotifyArg                            /* Argument to pass to xNotify */
    );
    
    
    /*
     ** CAPI3REF: String Comparison
     **
     ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
     ** and extensions to compare the contents of two buffers containing UTF-8
     ** strings in a case-independent fashion, using the same definition of "case
     ** independence" that SQLite uses internally when comparing identifiers.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *);
    SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int);
    
    /*
     ** CAPI3REF: String Globbing
     *
     ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
     ** string X matches the [GLOB] pattern P.
     ** ^The definition of [GLOB] pattern matching used in
     ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
     ** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function
     ** is case sensitive.
     **
     ** Note that this routine returns zero on a match and non-zero if the strings
     ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
     **
     ** See also: [sqlite3_strlike()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr);
    
    /*
     ** CAPI3REF: String LIKE Matching
     *
     ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
     ** string X matches the [LIKE] pattern P with escape character E.
     ** ^The definition of [LIKE] pattern matching used in
     ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
     ** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without
     ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
     ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
     ** insensitive - equivalent upper and lower case ASCII characters match
     ** one another.
     **
     ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
     ** only ASCII characters are case folded.
     **
     ** Note that this routine returns zero on a match and non-zero if the strings
     ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
     **
     ** See also: [sqlite3_strglob()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
    
    /*
     ** CAPI3REF: Error Logging Interface
     **
     ** ^The [sqlite3_log()] interface writes a message into the [error log]
     ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
     ** ^If logging is enabled, the zFormat string and subsequent arguments are
     ** used with [sqlite3_snprintf()] to generate the final output string.
     **
     ** The sqlite3_log() interface is intended for use by extensions such as
     ** virtual tables, collating functions, and SQL functions.  While there is
     ** nothing to prevent an application from calling sqlite3_log(), doing so
     ** is considered bad form.
     **
     ** The zFormat string must not be NULL.
     **
     ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
     ** will not use dynamically allocated memory.  The log message is stored in
     ** a fixed-length buffer on the stack.  If the log message is longer than
     ** a few hundred characters, it will be truncated to the length of the
     ** buffer.
     */
    SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...);
    
    /*
     ** CAPI3REF: Write-Ahead Log Commit Hook
     ** METHOD: sqlite3
     **
     ** ^The [sqlite3_wal_hook()] function is used to register a callback that
     ** is invoked each time data is committed to a database in wal mode.
     **
     ** ^(The callback is invoked by SQLite after the commit has taken place and
     ** the associated write-lock on the database released)^, so the implementation
     ** may read, write or [checkpoint] the database as required.
     **
     ** ^The first parameter passed to the callback function when it is invoked
     ** is a copy of the third parameter passed to sqlite3_wal_hook() when
     ** registering the callback. ^The second is a copy of the database handle.
     ** ^The third parameter is the name of the database that was written to -
     ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
     ** is the number of pages currently in the write-ahead log file,
     ** including those that were just committed.
     **
     ** The callback function should normally return [SQLITE_OK].  ^If an error
     ** code is returned, that error will propagate back up through the
     ** SQLite code base to cause the statement that provoked the callback
     ** to report an error, though the commit will have still occurred. If the
     ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
     ** that does not correspond to any valid SQLite error code, the results
     ** are undefined.
     **
     ** A single database handle may have at most a single write-ahead log callback
     ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
     ** previously registered write-ahead log callback. ^Note that the
     ** [sqlite3_wal_autocheckpoint()] interface and the
     ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
     ** those overwrite any prior [sqlite3_wal_hook()] settings.
     */
    SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook(
                                                     sqlite3*,
                                                     int(*)(void *,sqlite3*,const char*,int),
                                                     void*
                                                     );
    
    /*
     ** CAPI3REF: Configure an auto-checkpoint
     ** METHOD: sqlite3
     **
     ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
     ** [sqlite3_wal_hook()] that causes any database on [database connection] D
     ** to automatically [checkpoint]
     ** after committing a transaction if there are N or
     ** more frames in the [write-ahead log] file.  ^Passing zero or
     ** a negative value as the nFrame parameter disables automatic
     ** checkpoints entirely.
     **
     ** ^The callback registered by this function replaces any existing callback
     ** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
     ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
     ** configured by this function.
     **
     ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
     ** from SQL.
     **
     ** ^Checkpoints initiated by this mechanism are
     ** [sqlite3_wal_checkpoint_v2|PASSIVE].
     **
     ** ^Every new [database connection] defaults to having the auto-checkpoint
     ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
     ** pages.  The use of this interface
     ** is only necessary if the default setting is found to be suboptimal
     ** for a particular application.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
    
    /*
     ** CAPI3REF: Checkpoint a database
     ** METHOD: sqlite3
     **
     ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
     ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
     **
     ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
     ** [write-ahead log] for database X on [database connection] D to be
     ** transferred into the database file and for the write-ahead log to
     ** be reset.  See the [checkpointing] documentation for addition
     ** information.
     **
     ** This interface used to be the only way to cause a checkpoint to
     ** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
     ** interface was added.  This interface is retained for backwards
     ** compatibility and as a convenience for applications that need to manually
     ** start a callback but which do not need the full power (and corresponding
     ** complication) of [sqlite3_wal_checkpoint_v2()].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
    
    /*
     ** CAPI3REF: Checkpoint a database
     ** METHOD: sqlite3
     **
     ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
     ** operation on database X of [database connection] D in mode M.  Status
     ** information is written back into integers pointed to by L and C.)^
     ** ^(The M parameter must be a valid [checkpoint mode]:)^
     **
     ** <dl>
     ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
     **   ^Checkpoint as many frames as possible without waiting for any database
     **   readers or writers to finish, then sync the database file if all frames
     **   in the log were checkpointed. ^The [busy-handler callback]
     **   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
     **   ^On the other hand, passive mode might leave the checkpoint unfinished
     **   if there are concurrent readers or writers.
     **
     ** <dt>SQLITE_CHECKPOINT_FULL<dd>
     **   ^This mode blocks (it invokes the
     **   [sqlite3_busy_handler|busy-handler callback]) until there is no
     **   database writer and all readers are reading from the most recent database
     **   snapshot. ^It then checkpoints all frames in the log file and syncs the
     **   database file. ^This mode blocks new database writers while it is pending,
     **   but new database readers are allowed to continue unimpeded.
     **
     ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
     **   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
     **   that after checkpointing the log file it blocks (calls the
     **   [busy-handler callback])
     **   until all readers are reading from the database file only. ^This ensures
     **   that the next writer will restart the log file from the beginning.
     **   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
     **   database writer attempts while it is pending, but does not impede readers.
     **
     ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
     **   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
     **   addition that it also truncates the log file to zero bytes just prior
     **   to a successful return.
     ** </dl>
     **
     ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
     ** the log file or to -1 if the checkpoint could not run because
     ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
     ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
     ** log file (including any that were already checkpointed before the function
     ** was called) or to -1 if the checkpoint could not run due to an error or
     ** because the database is not in WAL mode. ^Note that upon successful
     ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
     ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
     **
     ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
     ** any other process is running a checkpoint operation at the same time, the
     ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
     ** busy-handler configured, it will not be invoked in this case.
     **
     ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
     ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
     ** obtained immediately, and a busy-handler is configured, it is invoked and
     ** the writer lock retried until either the busy-handler returns 0 or the lock
     ** is successfully obtained. ^The busy-handler is also invoked while waiting for
     ** database readers as described above. ^If the busy-handler returns 0 before
     ** the writer lock is obtained or while waiting for database readers, the
     ** checkpoint operation proceeds from that point in the same way as
     ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
     ** without blocking any further. ^SQLITE_BUSY is returned in this case.
     **
     ** ^If parameter zDb is NULL or points to a zero length string, then the
     ** specified operation is attempted on all WAL databases [attached] to
     ** [database connection] db.  In this case the
     ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
     ** an SQLITE_BUSY error is encountered when processing one or more of the
     ** attached WAL databases, the operation is still attempted on any remaining
     ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
     ** error occurs while processing an attached database, processing is abandoned
     ** and the error code is returned to the caller immediately. ^If no error
     ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
     ** databases, SQLITE_OK is returned.
     **
     ** ^If database zDb is the name of an attached database that is not in WAL
     ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
     ** zDb is not NULL (or a zero length string) and is not the name of any
     ** attached database, SQLITE_ERROR is returned to the caller.
     **
     ** ^Unless it returns SQLITE_MISUSE,
     ** the sqlite3_wal_checkpoint_v2() interface
     ** sets the error information that is queried by
     ** [sqlite3_errcode()] and [sqlite3_errmsg()].
     **
     ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
     ** from SQL.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2(
                                                            sqlite3 *db,                    /* Database handle */
                                                            const char *zDb,                /* Name of attached database (or NULL) */
                                                            int eMode,                      /* SQLITE_CHECKPOINT_* value */
                                                            int *pnLog,                     /* OUT: Size of WAL log in frames */
                                                            int *pnCkpt                     /* OUT: Total number of frames checkpointed */
    );
    
    /*
     ** CAPI3REF: Checkpoint Mode Values
     ** KEYWORDS: {checkpoint mode}
     **
     ** These constants define all valid values for the "checkpoint mode" passed
     ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
     ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
     ** meaning of each of these checkpoint modes.
     */
#define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */
#define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */
#define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for for readers */
#define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */
    
    /*
     ** CAPI3REF: Virtual Table Interface Configuration
     **
     ** This function may be called by either the [xConnect] or [xCreate] method
     ** of a [virtual table] implementation to configure
     ** various facets of the virtual table interface.
     **
     ** If this interface is invoked outside the context of an xConnect or
     ** xCreate virtual table method then the behavior is undefined.
     **
     ** At present, there is only one option that may be configured using
     ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
     ** may be added in the future.
     */
    SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...);
    
    /*
     ** CAPI3REF: Virtual Table Configuration Options
     **
     ** These macros define the various options to the
     ** [sqlite3_vtab_config()] interface that [virtual table] implementations
     ** can use to customize and optimize their behavior.
     **
     ** <dl>
     ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
     ** <dd>Calls of the form
     ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
     ** where X is an integer.  If X is zero, then the [virtual table] whose
     ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
     ** support constraints.  In this configuration (which is the default) if
     ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
     ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
     ** specified as part of the users SQL statement, regardless of the actual
     ** ON CONFLICT mode specified.
     **
     ** If X is non-zero, then the virtual table implementation guarantees
     ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
     ** any modifications to internal or persistent data structures have been made.
     ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 
     ** is able to roll back a statement or database transaction, and abandon
     ** or continue processing the current SQL statement as appropriate. 
     ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
     ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
     ** had been ABORT.
     **
     ** Virtual table implementations that are required to handle OR REPLACE
     ** must do so within the [xUpdate] method. If a call to the 
     ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 
     ** CONFLICT policy is REPLACE, the virtual table implementation should 
     ** silently replace the appropriate rows within the xUpdate callback and
     ** return SQLITE_OK. Or, if this is not possible, it may return
     ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 
     ** constraint handling.
     ** </dl>
     */
#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
    
    /*
     ** CAPI3REF: Determine The Virtual Table Conflict Policy
     **
     ** This function may only be called from within a call to the [xUpdate] method
     ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
     ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
     ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
     ** of the SQL statement that triggered the call to the [xUpdate] method of the
     ** [virtual table].
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *);
    
    /*
     ** CAPI3REF: Conflict resolution modes
     ** KEYWORDS: {conflict resolution mode}
     **
     ** These constants are returned by [sqlite3_vtab_on_conflict()] to
     ** inform a [virtual table] implementation what the [ON CONFLICT] mode
     ** is for the SQL statement being evaluated.
     **
     ** Note that the [SQLITE_IGNORE] constant is also used as a potential
     ** return value from the [sqlite3_set_authorizer()] callback and that
     ** [SQLITE_ABORT] is also a [result code].
     */
#define SQLITE_ROLLBACK 1
    /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
#define SQLITE_FAIL     3
    /* #define SQLITE_ABORT 4  // Also an error code */
#define SQLITE_REPLACE  5
    
    /*
     ** CAPI3REF: Prepared Statement Scan Status Opcodes
     ** KEYWORDS: {scanstatus options}
     **
     ** The following constants can be used for the T parameter to the
     ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
     ** different metric for sqlite3_stmt_scanstatus() to return.
     **
     ** When the value returned to V is a string, space to hold that string is
     ** managed by the prepared statement S and will be automatically freed when
     ** S is finalized.
     **
     ** <dl>
     ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
     ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
     ** set to the total number of times that the X-th loop has run.</dd>
     **
     ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
     ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
     ** to the total number of rows examined by all iterations of the X-th loop.</dd>
     **
     ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
     ** <dd>^The "double" variable pointed to by the T parameter will be set to the
     ** query planner's estimate for the average number of rows output from each
     ** iteration of the X-th loop.  If the query planner's estimates was accurate,
     ** then this value will approximate the quotient NVISIT/NLOOP and the
     ** product of this value for all prior loops with the same SELECTID will
     ** be the NLOOP value for the current loop.
     **
     ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
     ** <dd>^The "const char *" variable pointed to by the T parameter will be set
     ** to a zero-terminated UTF-8 string containing the name of the index or table
     ** used for the X-th loop.
     **
     ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
     ** <dd>^The "const char *" variable pointed to by the T parameter will be set
     ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
     ** description for the X-th loop.
     **
     ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
     ** <dd>^The "int" variable pointed to by the T parameter will be set to the
     ** "select-id" for the X-th loop.  The select-id identifies which query or
     ** subquery the loop is part of.  The main query has a select-id of zero.
     ** The select-id is the same value as is output in the first column
     ** of an [EXPLAIN QUERY PLAN] query.
     ** </dl>
     */
#define SQLITE_SCANSTAT_NLOOP    0
#define SQLITE_SCANSTAT_NVISIT   1
#define SQLITE_SCANSTAT_EST      2
#define SQLITE_SCANSTAT_NAME     3
#define SQLITE_SCANSTAT_EXPLAIN  4
#define SQLITE_SCANSTAT_SELECTID 5
    
    /*
     ** CAPI3REF: Prepared Statement Scan Status
     ** METHOD: sqlite3_stmt
     **
     ** This interface returns information about the predicted and measured
     ** performance for pStmt.  Advanced applications can use this
     ** interface to compare the predicted and the measured performance and
     ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
     **
     ** Since this interface is expected to be rarely used, it is only
     ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
     ** compile-time option.
     **
     ** The "iScanStatusOp" parameter determines which status information to return.
     ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
     ** of this interface is undefined.
     ** ^The requested measurement is written into a variable pointed to by
     ** the "pOut" parameter.
     ** Parameter "idx" identifies the specific loop to retrieve statistics for.
     ** Loops are numbered starting from zero. ^If idx is out of range - less than
     ** zero or greater than or equal to the total number of loops used to implement
     ** the statement - a non-zero value is returned and the variable that pOut
     ** points to is unchanged.
     **
     ** ^Statistics might not be available for all loops in all statements. ^In cases
     ** where there exist loops with no available statistics, this function behaves
     ** as if the loop did not exist - it returns non-zero and leave the variable
     ** that pOut points to unchanged.
     **
     ** See also: [sqlite3_stmt_scanstatus_reset()]
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus(
                                                          sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
                                                          int idx,                  /* Index of loop to report on */
                                                          int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
                                                          void *pOut                /* Result written here */
    );     
    
    /*
     ** CAPI3REF: Zero Scan-Status Counters
     ** METHOD: sqlite3_stmt
     **
     ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
     **
     ** This API is only available if the library is built with pre-processor
     ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
     */
    SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
    
    /*
     ** CAPI3REF: Flush caches to disk mid-transaction
     **
     ** ^If a write-transaction is open on [database connection] D when the
     ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
     ** pages in the pager-cache that are not currently in use are written out 
     ** to disk. A dirty page may be in use if a database cursor created by an
     ** active SQL statement is reading from it, or if it is page 1 of a database
     ** file (page 1 is always "in use").  ^The [sqlite3_db_cacheflush(D)]
     ** interface flushes caches for all schemas - "main", "temp", and
     ** any [attached] databases.
     **
     ** ^If this function needs to obtain extra database locks before dirty pages 
     ** can be flushed to disk, it does so. ^If those locks cannot be obtained 
     ** immediately and there is a busy-handler callback configured, it is invoked
     ** in the usual manner. ^If the required lock still cannot be obtained, then
     ** the database is skipped and an attempt made to flush any dirty pages
     ** belonging to the next (if any) database. ^If any databases are skipped
     ** because locks cannot be obtained, but no other error occurs, this
     ** function returns SQLITE_BUSY.
     **
     ** ^If any other error occurs while flushing dirty pages to disk (for
     ** example an IO error or out-of-memory condition), then processing is
     ** abandoned and an SQLite [error code] is returned to the caller immediately.
     **
     ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
     **
     ** ^This function does not set the database handle error code or message
     ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*);
    
    /*
     ** CAPI3REF: Database Snapshot
     ** KEYWORDS: {snapshot}
     ** EXPERIMENTAL
     **
     ** An instance of the snapshot object records the state of a [WAL mode]
     ** database for some specific point in history.
     **
     ** In [WAL mode], multiple [database connections] that are open on the
     ** same database file can each be reading a different historical version
     ** of the database file.  When a [database connection] begins a read
     ** transaction, that connection sees an unchanging copy of the database
     ** as it existed for the point in time when the transaction first started.
     ** Subsequent changes to the database from other connections are not seen
     ** by the reader until a new read transaction is started.
     **
     ** The sqlite3_snapshot object records state information about an historical
     ** version of the database file so that it is possible to later open a new read
     ** transaction that sees that historical version of the database rather than
     ** the most recent version.
     **
     ** The constructor for this object is [sqlite3_snapshot_get()].  The
     ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
     ** to an historical snapshot (if possible).  The destructor for 
     ** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
     */
    typedef struct sqlite3_snapshot sqlite3_snapshot;
    
    /*
     ** CAPI3REF: Record A Database Snapshot
     ** EXPERIMENTAL
     **
     ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
     ** new [sqlite3_snapshot] object that records the current state of
     ** schema S in database connection D.  ^On success, the
     ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
     ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
     ** ^If schema S of [database connection] D is not a [WAL mode] database
     ** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)]
     ** leaves the *P value unchanged and returns an appropriate [error code].
     **
     ** The [sqlite3_snapshot] object returned from a successful call to
     ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
     ** to avoid a memory leak.
     **
     ** The [sqlite3_snapshot_get()] interface is only available when the
     ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
     */
    SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get(
                                                                           sqlite3 *db,
                                                                           const char *zSchema,
                                                                           sqlite3_snapshot **ppSnapshot
                                                                           );
    
    /*
     ** CAPI3REF: Start a read transaction on an historical snapshot
     ** EXPERIMENTAL
     **
     ** ^The [sqlite3_snapshot_open(D,S,P)] interface attempts to move the
     ** read transaction that is currently open on schema S of
     ** [database connection] D so that it refers to historical [snapshot] P.
     ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
     ** or an appropriate [error code] if it fails.
     **
     ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
     ** the first operation, apart from other sqlite3_snapshot_open() calls,
     ** following the [BEGIN] that starts a new read transaction.
     ** ^A [snapshot] will fail to open if it has been overwritten by a 
     ** [checkpoint].  
     **
     ** The [sqlite3_snapshot_open()] interface is only available when the
     ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
     */
    SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open(
                                                                            sqlite3 *db,
                                                                            const char *zSchema,
                                                                            sqlite3_snapshot *pSnapshot
                                                                            );
    
    /*
     ** CAPI3REF: Destroy a snapshot
     ** EXPERIMENTAL
     **
     ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
     ** The application must eventually free every [sqlite3_snapshot] object
     ** using this routine to avoid a memory leak.
     **
     ** The [sqlite3_snapshot_free()] interface is only available when the
     ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
     */
    SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*);
    
    /*
     ** Undo the hack that converts floating point types to integer for
     ** builds on processors without floating point support.
     */
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif
    
#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif /* _SQLITE3_H_ */

/*
 ** 2010 August 30
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
 */

#ifndef _SQLITE3RTREE_H_
#define _SQLITE3RTREE_H_


#ifdef __cplusplus
extern "C" {
#endif
    
    typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
    typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
    
    /* The double-precision datatype used by RTree depends on the
     ** SQLITE_RTREE_INT_ONLY compile-time option.
     */
#ifdef SQLITE_RTREE_INT_ONLY
    typedef sqlite3_int64 sqlite3_rtree_dbl;
#else
    typedef double sqlite3_rtree_dbl;
#endif
    
    /*
     ** Register a geometry callback named zGeom that can be used as part of an
     ** R-Tree geometry query as follows:
     **
     **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback(
                                                                  sqlite3 *db,
                                                                  const char *zGeom,
                                                                  int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
                                                                  void *pContext
                                                                  );
    
    
    /*
     ** A pointer to a structure of the following type is passed as the first
     ** argument to callbacks registered using rtree_geometry_callback().
     */
    struct sqlite3_rtree_geometry {
        void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
        int nParam;                     /* Size of array aParam[] */
        sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
        void *pUser;                    /* Callback implementation user data */
        void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
    };
    
    /*
     ** Register a 2nd-generation geometry callback named zScore that can be 
     ** used as part of an R-Tree geometry query as follows:
     **
     **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
     */
    SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback(
                                                               sqlite3 *db,
                                                               const char *zQueryFunc,
                                                               int (*xQueryFunc)(sqlite3_rtree_query_info*),
                                                               void *pContext,
                                                               void (*xDestructor)(void*)
                                                               );
    
    
    /*
     ** A pointer to a structure of the following type is passed as the 
     ** argument to scored geometry callback registered using
     ** sqlite3_rtree_query_callback().
     **
     ** Note that the first 5 fields of this structure are identical to
     ** sqlite3_rtree_geometry.  This structure is a subclass of
     ** sqlite3_rtree_geometry.
     */
    struct sqlite3_rtree_query_info {
        void *pContext;                   /* pContext from when function registered */
        int nParam;                       /* Number of function parameters */
        sqlite3_rtree_dbl *aParam;        /* value of function parameters */
        void *pUser;                      /* callback can use this, if desired */
        void (*xDelUser)(void*);          /* function to free pUser */
        sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
        unsigned int *anQueue;            /* Number of pending entries in the queue */
        int nCoord;                       /* Number of coordinates */
        int iLevel;                       /* Level of current node or entry */
        int mxLevel;                      /* The largest iLevel value in the tree */
        sqlite3_int64 iRowid;             /* Rowid for current entry */
        sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
        int eParentWithin;                /* Visibility of parent node */
        int eWithin;                      /* OUT: Visiblity */
        sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
        /* The following fields are only available in 3.8.11 and later */
        sqlite3_value **apSqlParam;       /* Original SQL values of parameters */
    };
    
    /*
     ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
     */
#define NOT_WITHIN       0   /* Object completely outside of query region */
#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
#define FULLY_WITHIN     2   /* Object fully contained within query region */
    
    
#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif  /* ifndef _SQLITE3RTREE_H_ */

/*
 ** 2014 May 31
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
 ******************************************************************************
 **
 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 
 ** FTS5 may be extended with:
 **
 **     * custom tokenizers, and
 **     * custom auxiliary functions.
 */


#ifndef _FTS5_H
#define _FTS5_H


#ifdef __cplusplus
extern "C" {
#endif
    
    /*************************************************************************
     ** CUSTOM AUXILIARY FUNCTIONS
     **
     ** Virtual table implementations may overload SQL functions by implementing
     ** the sqlite3_module.xFindFunction() method.
     */
    
    typedef struct Fts5ExtensionApi Fts5ExtensionApi;
    typedef struct Fts5Context Fts5Context;
    typedef struct Fts5PhraseIter Fts5PhraseIter;
    
    typedef void (*fts5_extension_function)(
    const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
    Fts5Context *pFts,              /* First arg to pass to pApi functions */
    sqlite3_context *pCtx,          /* Context for returning result/error */
    int nVal,                       /* Number of values in apVal[] array */
    sqlite3_value **apVal           /* Array of trailing arguments */
    );
    
    struct Fts5PhraseIter {
        const unsigned char *a;
        const unsigned char *b;
    };
    
    /*
     ** EXTENSION API FUNCTIONS
     **
     ** xUserData(pFts):
     **   Return a copy of the context pointer the extension function was 
     **   registered with.
     **
     ** xColumnTotalSize(pFts, iCol, pnToken):
     **   If parameter iCol is less than zero, set output variable *pnToken
     **   to the total number of tokens in the FTS5 table. Or, if iCol is
     **   non-negative but less than the number of columns in the table, return
     **   the total number of tokens in column iCol, considering all rows in 
     **   the FTS5 table.
     **
     **   If parameter iCol is greater than or equal to the number of columns
     **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
     **   an OOM condition or IO error), an appropriate SQLite error code is 
     **   returned.
     **
     ** xColumnCount(pFts):
     **   Return the number of columns in the table.
     **
     ** xColumnSize(pFts, iCol, pnToken):
     **   If parameter iCol is less than zero, set output variable *pnToken
     **   to the total number of tokens in the current row. Or, if iCol is
     **   non-negative but less than the number of columns in the table, set
     **   *pnToken to the number of tokens in column iCol of the current row.
     **
     **   If parameter iCol is greater than or equal to the number of columns
     **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
     **   an OOM condition or IO error), an appropriate SQLite error code is 
     **   returned.
     **
     **   This function may be quite inefficient if used with an FTS5 table
     **   created with the "columnsize=0" option.
     **
     ** xColumnText:
     **   This function attempts to retrieve the text of column iCol of the
     **   current document. If successful, (*pz) is set to point to a buffer
     **   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
     **   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
     **   if an error occurs, an SQLite error code is returned and the final values
     **   of (*pz) and (*pn) are undefined.
     **
     ** xPhraseCount:
     **   Returns the number of phrases in the current query expression.
     **
     ** xPhraseSize:
     **   Returns the number of tokens in phrase iPhrase of the query. Phrases
     **   are numbered starting from zero.
     **
     ** xInstCount:
     **   Set *pnInst to the total number of occurrences of all phrases within
     **   the query within the current row. Return SQLITE_OK if successful, or
     **   an error code (i.e. SQLITE_NOMEM) if an error occurs.
     **
     **   This API can be quite slow if used with an FTS5 table created with the
     **   "detail=none" or "detail=column" option. If the FTS5 table is created 
     **   with either "detail=none" or "detail=column" and "content=" option 
     **   (i.e. if it is a contentless table), then this API always returns 0.
     **
     ** xInst:
     **   Query for the details of phrase match iIdx within the current row.
     **   Phrase matches are numbered starting from zero, so the iIdx argument
     **   should be greater than or equal to zero and smaller than the value
     **   output by xInstCount().
     **
     **   Usually, output parameter *piPhrase is set to the phrase number, *piCol
     **   to the column in which it occurs and *piOff the token offset of the
     **   first token of the phrase. The exception is if the table was created
     **   with the offsets=0 option specified. In this case *piOff is always
     **   set to -1.
     **
     **   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 
     **   if an error occurs.
     **
     **   This API can be quite slow if used with an FTS5 table created with the
     **   "detail=none" or "detail=column" option. 
     **
     ** xRowid:
     **   Returns the rowid of the current row.
     **
     ** xTokenize:
     **   Tokenize text using the tokenizer belonging to the FTS5 table.
     **
     ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
     **   This API function is used to query the FTS table for phrase iPhrase
     **   of the current query. Specifically, a query equivalent to:
     **
     **       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
     **
     **   with $p set to a phrase equivalent to the phrase iPhrase of the
     **   current query is executed. For each row visited, the callback function
     **   passed as the fourth argument is invoked. The context and API objects 
     **   passed to the callback function may be used to access the properties of
     **   each matched row. Invoking Api.xUserData() returns a copy of the pointer
     **   passed as the third argument to pUserData.
     **
     **   If the callback function returns any value other than SQLITE_OK, the
     **   query is abandoned and the xQueryPhrase function returns immediately.
     **   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
     **   Otherwise, the error code is propagated upwards.
     **
     **   If the query runs to completion without incident, SQLITE_OK is returned.
     **   Or, if some error occurs before the query completes or is aborted by
     **   the callback, an SQLite error code is returned.
     **
     **
     ** xSetAuxdata(pFts5, pAux, xDelete)
     **
     **   Save the pointer passed as the second argument as the extension functions 
     **   "auxiliary data". The pointer may then be retrieved by the current or any
     **   future invocation of the same fts5 extension function made as part of
     **   of the same MATCH query using the xGetAuxdata() API.
     **
     **   Each extension function is allocated a single auxiliary data slot for
     **   each FTS query (MATCH expression). If the extension function is invoked 
     **   more than once for a single FTS query, then all invocations share a 
     **   single auxiliary data context.
     **
     **   If there is already an auxiliary data pointer when this function is
     **   invoked, then it is replaced by the new pointer. If an xDelete callback
     **   was specified along with the original pointer, it is invoked at this
     **   point.
     **
     **   The xDelete callback, if one is specified, is also invoked on the
     **   auxiliary data pointer after the FTS5 query has finished.
     **
     **   If an error (e.g. an OOM condition) occurs within this function, an
     **   the auxiliary data is set to NULL and an error code returned. If the
     **   xDelete parameter was not NULL, it is invoked on the auxiliary data
     **   pointer before returning.
     **
     **
     ** xGetAuxdata(pFts5, bClear)
     **
     **   Returns the current auxiliary data pointer for the fts5 extension 
     **   function. See the xSetAuxdata() method for details.
     **
     **   If the bClear argument is non-zero, then the auxiliary data is cleared
     **   (set to NULL) before this function returns. In this case the xDelete,
     **   if any, is not invoked.
     **
     **
     ** xRowCount(pFts5, pnRow)
     **
     **   This function is used to retrieve the total number of rows in the table.
     **   In other words, the same value that would be returned by:
     **
     **        SELECT count(*) FROM ftstable;
     **
     ** xPhraseFirst()
     **   This function is used, along with type Fts5PhraseIter and the xPhraseNext
     **   method, to iterate through all instances of a single query phrase within
     **   the current row. This is the same information as is accessible via the
     **   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
     **   to use, this API may be faster under some circumstances. To iterate 
     **   through instances of phrase iPhrase, use the following code:
     **
     **       Fts5PhraseIter iter;
     **       int iCol, iOff;
     **       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
     **           iCol>=0;
     **           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
     **       ){
     **         // An instance of phrase iPhrase at offset iOff of column iCol
     **       }
     **
     **   The Fts5PhraseIter structure is defined above. Applications should not
     **   modify this structure directly - it should only be used as shown above
     **   with the xPhraseFirst() and xPhraseNext() API methods (and by
     **   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
     **
     **   This API can be quite slow if used with an FTS5 table created with the
     **   "detail=none" or "detail=column" option. If the FTS5 table is created 
     **   with either "detail=none" or "detail=column" and "content=" option 
     **   (i.e. if it is a contentless table), then this API always iterates
     **   through an empty set (all calls to xPhraseFirst() set iCol to -1).
     **
     ** xPhraseNext()
     **   See xPhraseFirst above.
     **
     ** xPhraseFirstColumn()
     **   This function and xPhraseNextColumn() are similar to the xPhraseFirst()
     **   and xPhraseNext() APIs described above. The difference is that instead
     **   of iterating through all instances of a phrase in the current row, these
     **   APIs are used to iterate through the set of columns in the current row
     **   that contain one or more instances of a specified phrase. For example:
     **
     **       Fts5PhraseIter iter;
     **       int iCol;
     **       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
     **           iCol>=0;
     **           pApi->xPhraseNextColumn(pFts, &iter, &iCol)
     **       ){
     **         // Column iCol contains at least one instance of phrase iPhrase
     **       }
     **
     **   This API can be quite slow if used with an FTS5 table created with the
     **   "detail=none" option. If the FTS5 table is created with either 
     **   "detail=none" "content=" option (i.e. if it is a contentless table), 
     **   then this API always iterates through an empty set (all calls to 
     **   xPhraseFirstColumn() set iCol to -1).
     **
     **   The information accessed using this API and its companion
     **   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
     **   (or xInst/xInstCount). The chief advantage of this API is that it is
     **   significantly more efficient than those alternatives when used with
     **   "detail=column" tables.  
     **
     ** xPhraseNextColumn()
     **   See xPhraseFirstColumn above.
     */
    struct Fts5ExtensionApi {
        int iVersion;                   /* Currently always set to 3 */
        
        void *(*xUserData)(Fts5Context*);
        
        int (*xColumnCount)(Fts5Context*);
        int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
        int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
        
        int (*xTokenize)(Fts5Context*, 
                         const char *pText, int nText, /* Text to tokenize */
                         void *pCtx,                   /* Context passed to xToken() */
                         int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
                         );
        
        int (*xPhraseCount)(Fts5Context*);
        int (*xPhraseSize)(Fts5Context*, int iPhrase);
        
        int (*xInstCount)(Fts5Context*, int *pnInst);
        int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
        
        sqlite3_int64 (*xRowid)(Fts5Context*);
        int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
        int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
        
        int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
                            int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
                            );
        int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
        void *(*xGetAuxdata)(Fts5Context*, int bClear);
        
        int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
        void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
        
        int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
        void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
    };
    
    /* 
     ** CUSTOM AUXILIARY FUNCTIONS
     *************************************************************************/
    
    /*************************************************************************
     ** CUSTOM TOKENIZERS
     **
     ** Applications may also register custom tokenizer types. A tokenizer 
     ** is registered by providing fts5 with a populated instance of the 
     ** following structure. All structure methods must be defined, setting
     ** any member of the fts5_tokenizer struct to NULL leads to undefined
     ** behaviour. The structure methods are expected to function as follows:
     **
     ** xCreate:
     **   This function is used to allocate and inititalize a tokenizer instance.
     **   A tokenizer instance is required to actually tokenize text.
     **
     **   The first argument passed to this function is a copy of the (void*)
     **   pointer provided by the application when the fts5_tokenizer object
     **   was registered with FTS5 (the third argument to xCreateTokenizer()). 
     **   The second and third arguments are an array of nul-terminated strings
     **   containing the tokenizer arguments, if any, specified following the
     **   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
     **   to create the FTS5 table.
     **
     **   The final argument is an output variable. If successful, (*ppOut) 
     **   should be set to point to the new tokenizer handle and SQLITE_OK
     **   returned. If an error occurs, some value other than SQLITE_OK should
     **   be returned. In this case, fts5 assumes that the final value of *ppOut 
     **   is undefined.
     **
     ** xDelete:
     **   This function is invoked to delete a tokenizer handle previously
     **   allocated using xCreate(). Fts5 guarantees that this function will
     **   be invoked exactly once for each successful call to xCreate().
     **
     ** xTokenize:
     **   This function is expected to tokenize the nText byte string indicated 
     **   by argument pText. pText may or may not be nul-terminated. The first
     **   argument passed to this function is a pointer to an Fts5Tokenizer object
     **   returned by an earlier call to xCreate().
     **
     **   The second argument indicates the reason that FTS5 is requesting
     **   tokenization of the supplied text. This is always one of the following
     **   four values:
     **
     **   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
     **            or removed from the FTS table. The tokenizer is being invoked to
     **            determine the set of tokens to add to (or delete from) the
     **            FTS index.
     **
     **       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 
     **            against the FTS index. The tokenizer is being called to tokenize 
     **            a bareword or quoted string specified as part of the query.
     **
     **       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
     **            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
     **            followed by a "*" character, indicating that the last token
     **            returned by the tokenizer will be treated as a token prefix.
     **
     **       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 
     **            satisfy an fts5_api.xTokenize() request made by an auxiliary
     **            function. Or an fts5_api.xColumnSize() request made by the same
     **            on a columnsize=0 database.  
     **   </ul>
     **
     **   For each token in the input string, the supplied callback xToken() must
     **   be invoked. The first argument to it should be a copy of the pointer
     **   passed as the second argument to xTokenize(). The third and fourth
     **   arguments are a pointer to a buffer containing the token text, and the
     **   size of the token in bytes. The 4th and 5th arguments are the byte offsets
     **   of the first byte of and first byte immediately following the text from
     **   which the token is derived within the input.
     **
     **   The second argument passed to the xToken() callback ("tflags") should
     **   normally be set to 0. The exception is if the tokenizer supports 
     **   synonyms. In this case see the discussion below for details.
     **
     **   FTS5 assumes the xToken() callback is invoked for each token in the 
     **   order that they occur within the input text.
     **
     **   If an xToken() callback returns any value other than SQLITE_OK, then
     **   the tokenization should be abandoned and the xTokenize() method should
     **   immediately return a copy of the xToken() return value. Or, if the
     **   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
     **   if an error occurs with the xTokenize() implementation itself, it
     **   may abandon the tokenization and return any error code other than
     **   SQLITE_OK or SQLITE_DONE.
     **
     ** SYNONYM SUPPORT
     **
     **   Custom tokenizers may also support synonyms. Consider a case in which a
     **   user wishes to query for a phrase such as "first place". Using the 
     **   built-in tokenizers, the FTS5 query 'first + place' will match instances
     **   of "first place" within the document set, but not alternative forms
     **   such as "1st place". In some applications, it would be better to match
     **   all instances of "first place" or "1st place" regardless of which form
     **   the user specified in the MATCH query text.
     **
     **   There are several ways to approach this in FTS5:
     **
     **   <ol><li> By mapping all synonyms to a single token. In this case, the 
     **            In the above example, this means that the tokenizer returns the
     **            same token for inputs "first" and "1st". Say that token is in
     **            fact "first", so that when the user inserts the document "I won
     **            1st place" entries are added to the index for tokens "i", "won",
     **            "first" and "place". If the user then queries for '1st + place',
     **            the tokenizer substitutes "first" for "1st" and the query works
     **            as expected.
     **
     **       <li> By adding multiple synonyms for a single term to the FTS index.
     **            In this case, when tokenizing query text, the tokenizer may 
     **            provide multiple synonyms for a single term within the document.
     **            FTS5 then queries the index for each synonym individually. For
     **            example, faced with the query:
     **
     **   <codeblock>
     **     ... MATCH 'first place'</codeblock>
     **
     **            the tokenizer offers both "1st" and "first" as synonyms for the
     **            first token in the MATCH query and FTS5 effectively runs a query 
     **            similar to:
     **
     **   <codeblock>
     **     ... MATCH '(first OR 1st) place'</codeblock>
     **
     **            except that, for the purposes of auxiliary functions, the query
     **            still appears to contain just two phrases - "(first OR 1st)" 
     **            being treated as a single phrase.
     **
     **       <li> By adding multiple synonyms for a single term to the FTS index.
     **            Using this method, when tokenizing document text, the tokenizer
     **            provides multiple synonyms for each token. So that when a 
     **            document such as "I won first place" is tokenized, entries are
     **            added to the FTS index for "i", "won", "first", "1st" and
     **            "place".
     **
     **            This way, even if the tokenizer does not provide synonyms
     **            when tokenizing query text (it should not - to do would be
     **            inefficient), it doesn't matter if the user queries for 
     **            'first + place' or '1st + place', as there are entires in the
     **            FTS index corresponding to both forms of the first token.
     **   </ol>
     **
     **   Whether it is parsing document or query text, any call to xToken that
     **   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
     **   is considered to supply a synonym for the previous token. For example,
     **   when parsing the document "I won first place", a tokenizer that supports
     **   synonyms would call xToken() 5 times, as follows:
     **
     **   <codeblock>
     **       xToken(pCtx, 0, "i",                      1,  0,  1);
     **       xToken(pCtx, 0, "won",                    3,  2,  5);
     **       xToken(pCtx, 0, "first",                  5,  6, 11);
     **       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
     **       xToken(pCtx, 0, "place",                  5, 12, 17);
     **</codeblock>
     **
     **   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
     **   xToken() is called. Multiple synonyms may be specified for a single token
     **   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 
     **   There is no limit to the number of synonyms that may be provided for a
     **   single token.
     **
     **   In many cases, method (1) above is the best approach. It does not add 
     **   extra data to the FTS index or require FTS5 to query for multiple terms,
     **   so it is efficient in terms of disk space and query speed. However, it
     **   does not support prefix queries very well. If, as suggested above, the
     **   token "first" is subsituted for "1st" by the tokenizer, then the query:
     **
     **   <codeblock>
     **     ... MATCH '1s*'</codeblock>
     **
     **   will not match documents that contain the token "1st" (as the tokenizer
     **   will probably not map "1s" to any prefix of "first").
     **
     **   For full prefix support, method (3) may be preferred. In this case, 
     **   because the index contains entries for both "first" and "1st", prefix
     **   queries such as 'fi*' or '1s*' will match correctly. However, because
     **   extra entries are added to the FTS index, this method uses more space
     **   within the database.
     **
     **   Method (2) offers a midpoint between (1) and (3). Using this method,
     **   a query such as '1s*' will match documents that contain the literal 
     **   token "1st", but not "first" (assuming the tokenizer is not able to
     **   provide synonyms for prefixes). However, a non-prefix query like '1st'
     **   will match against "1st" and "first". This method does not require
     **   extra disk space, as no extra entries are added to the FTS index. 
     **   On the other hand, it may require more CPU cycles to run MATCH queries,
     **   as separate queries of the FTS index are required for each synonym.
     **
     **   When using methods (2) or (3), it is important that the tokenizer only
     **   provide synonyms when tokenizing document text (method (2)) or query
     **   text (method (3)), not both. Doing so will not cause any errors, but is
     **   inefficient.
     */
    typedef struct Fts5Tokenizer Fts5Tokenizer;
    typedef struct fts5_tokenizer fts5_tokenizer;
    struct fts5_tokenizer {
        int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
        void (*xDelete)(Fts5Tokenizer*);
        int (*xTokenize)(Fts5Tokenizer*, 
                         void *pCtx,
                         int flags,            /* Mask of FTS5_TOKENIZE_* flags */
                         const char *pText, int nText, 
                         int (*xToken)(
                                       void *pCtx,         /* Copy of 2nd argument to xTokenize() */
                                       int tflags,         /* Mask of FTS5_TOKEN_* flags */
                                       const char *pToken, /* Pointer to buffer containing token */
                                       int nToken,         /* Size of token in bytes */
                                       int iStart,         /* Byte offset of token within input text */
                                       int iEnd            /* Byte offset of end of token within input text */
                                       )
                         );
    };
    
    /* Flags that may be passed as the third argument to xTokenize() */
#define FTS5_TOKENIZE_QUERY     0x0001
#define FTS5_TOKENIZE_PREFIX    0x0002
#define FTS5_TOKENIZE_DOCUMENT  0x0004
#define FTS5_TOKENIZE_AUX       0x0008
    
    /* Flags that may be passed by the tokenizer implementation back to FTS5
     ** as the third argument to the supplied xToken callback. */
#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */
    
    /*
     ** END OF CUSTOM TOKENIZERS
     *************************************************************************/
    
    /*************************************************************************
     ** FTS5 EXTENSION REGISTRATION API
     */
    typedef struct fts5_api fts5_api;
    struct fts5_api {
        int iVersion;                   /* Currently always set to 2 */
        
        /* Create a new tokenizer */
        int (*xCreateTokenizer)(
                                fts5_api *pApi,
                                const char *zName,
                                void *pContext,
                                fts5_tokenizer *pTokenizer,
                                void (*xDestroy)(void*)
                                );
        
        /* Find an existing tokenizer */
        int (*xFindTokenizer)(
                              fts5_api *pApi,
                              const char *zName,
                              void **ppContext,
                              fts5_tokenizer *pTokenizer
                              );
        
        /* Create a new auxiliary function */
        int (*xCreateFunction)(
                               fts5_api *pApi,
                               const char *zName,
                               void *pContext,
                               fts5_extension_function xFunction,
                               void (*xDestroy)(void*)
                               );
    };
    
    /*
     ** END OF REGISTRATION API
     *************************************************************************/
    
#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif /* _FTS5_H */

#pragma clang diagnostic pop