SQLite

** on how SQLite interfaces are suppose 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.
**
** @(#) $Id: sqlite.h.in,v 1.276 2007/12/06 02:42:08 drh Exp $
*/
#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 SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif

/*
** CAPI3REF: Compile-Time Library Version Numbers {F10010}
**
** {F10011} The #define in the sqlite3.h header file named

** SQLITE_VERSION resolves to a string literal that identifies

** the version of the SQLite library in the format "X.Y.Z", where
** X is the major version number, Y is the minor version number and Z
** is the release number.  The X.Y.Z might be followed by "alpha" or "beta".
** {END} For example "3.1.1beta".
**
** The X value is always 3 in SQLite.  The X value only changes when
** backwards compatibility is broken and we intend to never break
** backwards compatibility.  The Y value only changes when
** there are major feature enhancements that are forwards compatible
** but not backwards compatible.  The Z value is incremented with
** each release but resets back to 0 when Y is incremented.
**
** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer
** with the value  (X*1000000 + Y*1000 + Z) where X, Y, and Z are as
** with SQLITE_VERSION. {END} For example, for version "3.1.1beta", 
** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using 
** version 3.1.1 or greater at compile time, programs may use the test 
** (SQLITE_VERSION_NUMBER>=3001001).
**
** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
*/
#define SQLITE_VERSION         "--VERS--"
#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--

/*
** CAPI3REF: Run-Time Library Version Numbers {F10020}
**
** {F10021} The sqlite3_libversion_number() interface returns an integer
** equal to [SQLITE_VERSION_NUMBER].  {END} The value returned
** by this routine should only be different from the header values
** if the application is compiled using an sqlite3.h header from a
** different version of SQLite than library.  Cautious programmers might
** include a check in their application to verify that 
** sqlite3_libversion_number() always returns the value 
** [SQLITE_VERSION_NUMBER].
**
** {F10022} The sqlite3_version[] string constant contains the text of the
** [SQLITE_VERSION] string. {F10023} The sqlite3_libversion() function returns
** a pointer to the sqlite3_version[] string constant. {END} The 
** sqlite3_libversion() function
** is provided for DLL users who can only access functions and not
** constants within the DLL.
*/
SQLITE_EXTERN const char sqlite3_version[];
const char *sqlite3_libversion(void);
int sqlite3_libversion_number(void);

/*
** CAPI3REF: Test To See If The Library Is Threadsafe {F10100}
**
** {F10101} The sqlite3_threadsafe() routine returns nonzero
** if SQLite was compiled with its mutexes enabled or zero if

** SQLite was compiled with mutexes disabled. {END}  If this
** routine returns false, then it is not safe for simultaneously
** running threads to both invoke SQLite interfaces.
**
** Really all this routine does is return true if SQLite was
** compiled with the -DSQLITE_THREADSAFE=1 option and false if
** compiled with -DSQLITE_THREADSAFE=0.  If SQLite uses an
** application-defined mutex subsystem, malloc subsystem, collating
** sequence, VFS, SQL function, progress callback, commit hook,
** extension, or other accessories and these add-ons are not
** threadsafe, then clearly the combination will not be threadsafe
** either.  Hence, this routine never reports that the library
** is guaranteed to be threadsafe, only when it is guaranteed not
** to be.
*/
int sqlite3_threadsafe(void);

/*
** CAPI3REF: Database Connection Handle {F12000}

#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite3_int64
#endif

/*
** CAPI3REF: Closing A Database Connection {F12010}
**
** {F12011} The sqlite3_close() interfaces destroys an [sqlite3] object
** allocated by a prior call to [sqlite3_open()], [sqlite3_open16()], or
** [sqlite3_open_v2()]. {F12012} Sqlite3_close() releases all
** memory used by the connection and closes all open files. {END}.
**
** {F12013} If the database connection contains
** [sqlite3_stmt | prepared statements] that have not been finalized
** by [sqlite3_finalize()], then sqlite3_close() returns SQLITE_BUSY
** and leaves the connection open.  {F12014} Giving sqlite3_close()
** a NULL pointer is a harmless no-op. {END}
**
** {U12015} Passing this routine a database connection that has already been
** closed results in undefined behavior. {U12016} If other interfaces that
** reference the same database connection are pending (either in the
** same thread or in different threads) when this routine is called,
** then the behavior is undefined and is almost certainly undesirable.
*/
int sqlite3_close(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 {F12100}
**
** {F12101} The sqlite3_exec() interface evaluates zero or more 
** UTF-8 encoded, semicolon-separated SQL statements in the zero-terminated
** string of its second argument.  {F12102} The SQL
** statements are evaluated in the context of the database connection
** specified by in the first argument.
** {F12103} SQL statements are prepared one by one using
** [sqlite3_prepare()] or the equivalent, evaluated
** using one or more calls to [sqlite3_step()], then destroyed
** using [sqlite3_finalize()]. {F12104} The return value of
** sqlite3_exec() is SQLITE_OK if all SQL statement run
** successfully.
**

** that is passed through to the callback function as its first parameter.
**
** {F12108} The 2nd parameter to the callback function is the number of
** columns in the query result.  {F12109} The 3rd parameter to the callback
** is an array of pointers to strings holding the values for each column
** as extracted using [sqlite3_column_text()].  NULL values in the result
** set result in a NULL pointer.  All other value are in their UTF-8
** string representation. {F12117}
** The 4th parameter to the callback is an array of strings
** obtained using [sqlite3_column_name()] and holding
** the names of each column, also in UTF-8.
**
** {F12110} The callback function may be NULL, even for queries.  A NULL
** callback is not an error.  It just means that no callback
** will be invoked. 
**
** {F12112} If an error occurs while parsing or evaluating the SQL
** then an appropriate error message is written into memory obtained
** from [sqlite3_malloc()] and *errmsg is made to point to that message
** assuming errmsg is not NULL.  
** {U12113} The calling function is responsible for freeing the memory
** using [sqlite3_free()].
** {F12116} If [sqlite3_malloc()] fails while attempting to generate
** the error message, *errmsg is set to NULL.
** {F12114} If errmsg is NULL then no attempt is made to generate an
** error message. <todo>Is the return code SQLITE_NOMEM or the original
** error code?</todo> <todo>What happens if there are multiple errors?
** Do we get code for the first error, or is the choice of reported
** error arbitrary?</todo>
**
** {F12115} The return value is is SQLITE_OK if there are no errors and
** some other [SQLITE_OK | return code] if there is an error.  
** The particular return value depends on the type of error.  {END}
*/
int sqlite3_exec(
  sqlite3*,                                  /* An open database */
  const char *sql,                           /* SQL to be evaluted */
  int (*callback)(void*,int,char**,char**),  /* Callback function */
  void *,                                    /* 1st argument to callback */
  char **errmsg                              /* Error msg written here */
);

/*
** CAPI3REF: Result Codes {F10210}
** KEYWORDS: SQLITE_OK
**
** Many SQLite functions return an integer result code from the set shown
** above in order to indicates success or failure.
**
** {F10211} The result codes shown here are the only ones returned 
** by SQLite in its default configuration. {F10212} However, the
** [sqlite3_extended_result_codes()] API can be used to set a database
** connectoin to return more detailed result codes. {END}
**
** See also: [SQLITE_IOERR_READ | extended result codes]
**
*/
#define SQLITE_OK           0   /* Successful result */

#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
/* end-of-error-codes */

/*
** CAPI3REF: Extended Result Codes {F10220}
**
** In its default configuration, SQLite API routines return one of 26 integer
** [SQLITE_OK | result codes].  However, experience has shown that
** many of these result codes are too course-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. {F10221} The extended result codes are enabled or disabled
** for each database connection using the [sqlite3_extended_result_codes()]
** API. {END}
** 
** Some of the available extended result codes are listed above.

*/
#define SQLITE_FCNTL_LOCKSTATE        1

/*
** CAPI3REF: Mutex Handle {F17110}
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  {F17111} The SQLite core never looks
** at the internal representation of an [sqlite3_mutex]. {END} It only
** deals with pointers to the [sqlite3_mutex] object.
**
** Mutexes are created using [sqlite3_mutex_alloc()].
*/
typedef struct sqlite3_mutex sqlite3_mutex;

/*

** 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.
**
** {F11141} SQLite will guarantee that the zFilename string passed to
** xOpen() is a full pathname as generated by xFullPathname() and
** that the string will be valid and unchanged until xClose() is
** called.  {END} So the [sqlite3_file] can store a pointer to the
** filename if it needs to remember the filename for some reason.
**
** {F11142} 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]. {END}
** If xOpen() opens a file read-only then it sets *pOutFlags to
** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be
** set.
** 
** {F11143} 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]
** </ul> {END}
**
** The file I/O implementation can use the object type flags to
** changes 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 are
** also a no-op.  Any attempt to read the journal return SQLITE_IOERR.
** Or the implementation might recognize the a database file will
** be doing page-aligned sector reads and writes in a random order
** and set up its I/O subsystem accordingly.
** 
** {F11144} SQLite might also add one of the following flags to the xOpen
** method:
** 
** <ul>
** <li> [SQLITE_OPEN_DELETEONCLOSE]
** <li> [SQLITE_OPEN_EXCLUSIVE]
** </ul>
** 
** {F11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
** deleted when it is closed.  {F11146} The [SQLITE_OPEN_DELETEONCLOSE]
** will be set for TEMP  databases, journals and for subjournals. 
** {F11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened
** for exclusive access.  This flag is set for all files except
** for the main database file. {END}
** 
** {F11148} At least szOsFile bytes of memory is allocated by SQLite 
** to hold the  [sqlite3_file] structure passed as the third 
** argument to xOpen.  {END}  The xOpen method does not have to

** allocate the structure; it should just fill it in.
** 
** {F11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 
** to test for the existance of a file,
** or [SQLITE_ACCESS_READWRITE] to test to see
** if a file is readable and writable, or [SQLITE_ACCESS_READ]
** to test to see if a file is at least readable.  {END} The file can be a 
** directory.
** 
** {F11150} SQLite will always allocate at least mxPathname+1 byte for
** the output buffers for xGetTempname and xFullPathname. {F11151} The exact
** size of the output buffer is also passed as a parameter to both 
** methods. {END} If the output buffer is not large enough, SQLITE_CANTOPEN
** should be returned. As 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(), and xCurrentTime() 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

  int (*xSleep)(sqlite3_vfs*, int microseconds);
  int (*xCurrentTime)(sqlite3_vfs*, double*);
  /* New fields may be appended in figure versions.  The iVersion
  ** value will increment whenever this happens. */
};

/*
** CAPI3REF: Flags for the xAccess VFS method {F11190}
**
** {F11191} These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object. {END}  They determine
** the kind of what kind of permissions the xAccess method is
** looking for.  {F11192} With SQLITE_ACCESS_EXISTS, the xAccess method
** simply checks to see if the file exists. {F11193} With
** SQLITE_ACCESS_READWRITE, the xAccess method checks to see
** if the file is both readable and writable.  {F11194} With
** SQLITE_ACCESS_READ the xAccess method
** checks to see if the file is readable.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1
#define SQLITE_ACCESS_READ      2

/*
** CAPI3REF: Enable Or Disable Extended Result Codes {F12200}
**
** {F12201} The sqlite3_extended_result_codes() routine enables or disables the
** [SQLITE_IOERR_READ | extended result codes] feature on a database
** connection if its 2nd parameter is
** non-zero or zero, respectively. {F12202}
** By default, SQLite API routines return one of only 26 integer
** [SQLITE_OK | result codes].  {F12203} When extended result codes
** are enabled by this routine, the repetoire of result codes can be
** much larger and can (hopefully) provide more detailed information
** about the cause of an error.
**
** {F12204} The second argument is a boolean value that turns extended result

** or inserted or deleted by the most recently completed SQL statement
** on the connection specified by the first parameter. {F12242} Only
** changes that are directly specified by the INSERT, UPDATE, or
** DELETE statement are counted.  Auxiliary changes caused by
** triggers are not counted. {F12243} Use the [sqlite3_total_changes()] function
** to find the total number of changes including changes caused by triggers.
**
** {F12244} Within the body of a trigger, the sqlite3_changes() interface
** can be called to find the number of
** changes in the most recently completed INSERT, UPDATE, or DELETE
** statement within the body of the same trigger.
**
** {F12245} All changes are counted, even if they are later undone by a
** ROLLBACK or ABORT.  {F12246} Except, changes associated with creating and
** dropping tables are not counted.
**
** {F12247} If a callback invokes [sqlite3_exec()] or [sqlite3_step()]
** recursively, then the changes in the inner, recursive call are
** counted together with the changes in the outer call.
**

** statements executed as part of trigger programs.  {F12263} All changes
** are counted as soon as the statement that makes them is completed 
** (when the statement handle is passed to [sqlite3_reset()] or 
** [sqlite3_finalize()]). {END}
**
** See also the [sqlite3_change()] interface.
**
** {F12265} SQLite implements the command "DELETE FROM table" without
** a WHERE clause by dropping and recreating the table.  (This is much
** faster than going
** through and deleting individual elements form the table.)  Because of
** this optimization, the change count for "DELETE FROM table" will be
** zero regardless of the number of elements that were originally in the
** table. To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
**
** {U12264} If another thread makes changes on the same database connection

** immediately.
**
** {F12272} It is safe to call this routine from a thread different from the
** thread that is currently running the database operation. {U12273} 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 is very nearly finished at the time when sqlite3_interrupt()
** is called, then it might not have an opportunity to be interrupted.
** It might continue to completion.
** {F12274} The SQL operation that is interrupted will return
** [SQLITE_INTERRUPT].  {F12275} 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.
** {F12276} A call to sqlite3_interrupt() has no effect on SQL statements
** that are started after sqlite3_interrupt() returns.
*/
void sqlite3_interrupt(sqlite3*);

/*
** CAPI3REF: Determine If An SQL Statement Is Complete {F10510}
**
** These routines are useful for command-line input to determine if the
** currently entered text seems to form complete a SQL statement or
** if additional input is needed before sending the text into
** SQLite for parsing.  These routines return true if the input string
** appears to be a complete SQL statement.  A statement is judged to be
** complete if it ends with a semicolon and is not a fragment of a
** CREATE TRIGGER statement.  These routines do not parse the SQL and
** so will not detect syntactically incorrect SQL.
**
** {F10511} These functions return true if the given input string 
** ends with a semicolon optionally followed by whitespace or
** comments. {F10512} For sqlite3_complete(),
** the parameter must be a zero-terminated UTF-8 string. {F10513} For
** sqlite3_complete16(), a zero-terminated machine byte order UTF-16 string
** is required.  {F10514} These routines return false if the terminal

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310}
**
** {F12311} This routine identifies a callback function that might be
** invoked whenever an attempt is made to open a database table 
** that another thread or process has locked.
** {F12312} If the busy callback is NULL, then [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock.
** {F12313} If the busy callback is not NULL, then the
** callback will be invoked with two arguments.  {F12314} The
** first argument to the handler is a copy of the void* pointer which
** is the third argument to this routine.  {F12315} The second argument to
** the handler is the number of times that the busy handler has
** been invoked for this locking event.  {F12316} If the
** busy callback returns 0, then no additional attempts are made to
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
** {F12317} If the callback returns non-zero, then another attempt
** is made to open the database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that
** it will be invoked when there is lock contention. {F12319}
** If SQLite determines that invoking the busy handler could result in
** a deadlock, it will go ahead and return [SQLITE_BUSY] or
** [SQLITE_IOERR_BLOCKED] instead of invoking the
** busy handler. {END}
** 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.
**
** {F12321} The default busy callback is NULL. {END}
**
** {F12322} The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
** when SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache.  {F12323} SQLite will
** already hold a RESERVED lock on the database file, but it needs
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent

** the busy handler.
**
** {F12331} When operating in [sqlite3_enable_shared_cache | shared cache mode],
** only a single busy handler can be defined for each database file.
** So if two database connections share a single cache, then changing
** the busy handler on one connection will also change the busy
** handler in the other connection.  {F12332} The busy handler is invoked
** in the thread that was running when the lock contention occurs.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout {F12340}
**
** {F12341} This routine sets a [sqlite3_busy_handler | busy handler]
** that sleeps for a while when a
** table is locked.  {F12342} The handler will sleep multiple times until 
** at least "ms" milliseconds of sleeping have been done. {F12343} After
** "ms" milliseconds of sleeping, the handler returns 0 which
** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** {F12344} Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.

char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
char *sqlite3_snprintf(int,char*,const char*, ...);

/*
** CAPI3REF: Memory Allocation Subsystem {F17300}
**

** {F17301} The SQLite core  uses these three routines for all of its own
** internal memory allocation needs. {END}  "Core" in the previous sentence
** does not include operating-system specific VFS implementation.  The
** windows VFS uses native malloc and free for some operations.
**
** {F17302} The sqlite3_malloc() routine returns a pointer to a block
** of memory at least N bytes in length, where N is the parameter.
** {F17303} If sqlite3_malloc() is unable to obtain sufficient free
** memory, it returns a NULL pointer.  {F17304} If the parameter N to
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
** a NULL pointer.

** of at least N bytes in size or NULL if sufficient memory is unavailable.
** {F17314} 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() and the prior allocation is freed.
** {F17315} If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** {F17316} The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary. {END}
**
** {F17381} The default implementation
** of the memory allocation subsystem uses the malloc(), realloc()
** and free() provided by the standard C library. {F17382} However, if 
** SQLite is compiled with the following C preprocessor macro
**
** <blockquote> SQLITE_MEMORY_SIZE=<i>NNN</i> </blockquote>
**
** where <i>NNN</i> is an integer, then SQLite create a static
** array of at least <i>NNN</i> bytes in size and use that array
** for all of its dynamic memory allocation needs. {END}  Additional
** memory allocator options may be added in future releases.
**
** 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.
**
** The windows OS interface layer calls
** 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 are detected, but
** they are reported back as [SQLITE_CANTOPEN] or
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
*/

**
** {F17371} The sqlite3_memory_used() routine returns the
** number of bytes of memory currently outstanding (malloced but not freed).
** {F17372} The value returned by sqlite3_memory_used() includes
** any overhead added by SQLite, but not overhead added by the
** library malloc() that backs the sqlite3_malloc() implementation.
** {F17373} The sqlite3_memory_highwater() routines returns the
** maximum number of bytes that have been outstanding at any time
** since the highwater mark was last reset.
** {F17374} The byte count returned by sqlite3_memory_highwater()
** uses the same byte counting rules as sqlite3_memory_used(). {END}
** In other words, overhead added internally by SQLite is counted,
** but overhead from the underlying system malloc is not.
** {F17375} If the parameter to sqlite3_memory_highwater() is true,
** then the highwater mark is reset to the current value of
** sqlite3_memory_used() and the prior highwater mark (before the
** reset) is returned.  {F17376}  If the parameter to 
** sqlite3_memory_highwater() is zero, then the highwater mark is
** unchanged.
*/
sqlite3_int64 sqlite3_memory_used(void);
sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

/*
** CAPI3REF: Compile-Time Authorization Callbacks {F12500}
**
** {F12501} This routine registers a authorizer callback with a particular
** database connection, supplied in the first argument. {F12502}
** 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()].  {F12503} 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.  {F12504} If the authorizer callback returns
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
** then [sqlite3_prepare_v2()] or equivalent call that triggered
** the authorizer shall
** fail with an SQLITE_ERROR error code and an appropriate error message. {END}
**
** When the callback returns [SQLITE_OK], that means the operation
** requested is ok.  {F12505} When the callback returns [SQLITE_DENY], the

** [sqlite3_prepare_v2()] or equivalent call that triggered the
** authorizer shall fail
** with an SQLITE_ERROR error code and an error message explaining that
** access is denied. {F12506} If the authorizer code (the 2nd parameter
** to the authorizer callback is anything other than [SQLITE_READ], then
** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 
** If the authorizer code is [SQLITE_READ] and the callback returns
** [SQLITE_IGNORE] then the prepared statement is constructed to
** insert a NULL value in place of the table column that would have
** been read if [SQLITE_OK] had been returned. {END}
**
** {F12510} The first parameter to the authorizer callback is a copy of
** the third parameter to the sqlite3_set_authorizer() interface.
** {F12511} The second parameter to the callback is an integer 
** [SQLITE_COPY | action code] that specifies the particular action
** to be authorized. {END} The available action codes are
** [SQLITE_COPY | documented separately].  {F12512} The third through sixth

int sqlite3_set_authorizer(
  sqlite3*,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pUserData
);

/*
** CAPI3REF: Authorizer Return Codes {F12590}
**
** 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.
*/
#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 {F12550}
**
** The [sqlite3_set_authorizer()] interface registers a callback function
** that is invoked to authorizer certain SQL statement actions.  {F12551} 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. {END}
**
** These action code values signify what kind of operation is to be 
** authorized.  {F12552} 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. {F12553} The 5th parameter to the
** authorizer callback is the name of the database ("main", "temp", 
** etc.) if applicable. {F12554} 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_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   /* Function Name   NULL            */
#define SQLITE_COPY                  0   /* No longer used */

/*
** CAPI3REF: Tracing And Profiling Functions {F12280}
**
** These routines register callback functions that can be used for
** tracing and profiling the execution of SQL statements.
**
** {F12281} The callback function registered by sqlite3_trace() is invoked
** at the first [sqlite3_step()] for the evaluation of an SQL statement.
** {F12282} Only a single trace callback can be registered at a time.
** Each call to sqlite3_trace() overrides the previous.  {F12283} A
** NULL callback for sqlite3_trace() disables tracing.  {F12284} The
** first argument to the trace callback is a copy of the pointer which
** was the 3rd argument to sqlite3_trace.  {F12285} The second argument
** to the trace callback is a zero-terminated UTF8 string containing
** the original text of the SQL statement as it was passed into
** [sqlite3_prepare_v2()] or the equivalent. {END}  Note that the
** host parameter are not expanded in the SQL statement text.
**
** {F12287} The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  {F12288} The first parameter to the
** profile callback is a copy of the 3rd parameter to sqlite3_profile().
** {F12289} The second parameter to the profile callback is a
** zero-terminated UTF-8 string that contains the complete text of
** the SQL statement as it was processed by [sqlite3_prepare_v2()] or
** the equivalent.  {F12290} The third parameter to the profile 
** callback is an estimate of the number of nanoseconds of
** wall-clock time required to run the SQL statement from start
** to finish. {END}  
**
** The sqlite3_profile() API is currently considered experimental and
** is subject to change.
*/
void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
void *sqlite3_profile(sqlite3*,
   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

** UTF-16 in the native byte order if [sqlite3_open16()] is used.
**
** {F12708} Whether or not an error occurs when it is opened, resources
** associated with the [sqlite3*] handle should be released by passing it
** to [sqlite3_close()] when it is no longer required.
**
** {F12709} The [sqlite3_open_v2()] interface works like [sqlite3_open()] 
** except that it acccepts two additional parameters for additional control
** over the new database connection.  {F12710} The flags parameter can be
** one of:
**
** <ol>
** <li>  [SQLITE_OPEN_READONLY]
** <li>  [SQLITE_OPEN_READWRITE]
** <li>  [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]

int sqlite3_errcode(sqlite3 *db);
const char *sqlite3_errmsg(sqlite3*);
const void *sqlite3_errmsg16(sqlite3*);

/*
** CAPI3REF: SQL Statement Object {F13000}
**
** An instance of this object represent single SQL statements.  This
** object is variously known as a "prepared statement" or a 
** "compiled SQL statement" or simply as a "statement".
** 
** The life of a statement object goes something like this:
**
** <ol>
** <li> Create the object using [sqlite3_prepare_v2()] or a related
**      function.

** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
** use UTF-16. {END}
**
** {F13013} If the nByte argument is less
** than zero, then zSql is read up to the first zero terminator.
** {F13014} If nByte is non-negative, then it is the maximum number of 
** bytes read from zSql.  When nByte is non-negative, the
** zSql string ends at either the first '\000' or '\u0000' character or 
** until the nByte-th byte, whichever comes first. {END}
**
** {F13015} *pzTail is made to point to the first byte past the end of the
** first SQL statement in zSql.  These routines only compiles the first
** statement in zSql, so *pzTail is left pointing to what remains
** uncompiled. {END}
**
** {F13016} *ppStmt is left pointing to a compiled 
** [sqlite3_stmt | SQL statement structure] that can be
** executed using [sqlite3_step()].  Or if there is an error, *ppStmt may be
** set to NULL.  {F13017} If the input text contains no SQL (if the input
** is and empty string or a comment) then *ppStmt is set to NULL.
** {U13018} The calling procedure is responsible for deleting the
** compiled SQL statement
** using [sqlite3_finalize()] after it has finished with it.
**
** {F13019} On success, [SQLITE_OK] is returned.  Otherwise an 
** [SQLITE_ERROR | error code] is returned. {END}

** {F13101} If the compiled SQL statement passed as an argument was
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()],
** then this function returns a pointer to a zero-terminated string
** containing a copy of the original SQL statement. {F13102} The
** pointer is valid until the statement
** is deleted using sqlite3_finalize().
** {F13103} The string returned by sqlite3_sql() is always UTF8 even
** if a UTF16 string was originally entered using [sqlite3_prepare16_v2()]
** or the equivalent.
**
** {F13104} If the statement was compiled using either of the legacy
** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this
** function returns NULL.
*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF:  Dynamically Typed Value Object  {F15000}
**
** {F15001} SQLite uses the sqlite3_value object to represent all values
** that are or can be stored in a database table. {END}
** SQLite uses dynamic typing for the values it stores.  
** {F15002} Values stored in sqlite3_value objects can be
** be integers, floating point values, strings, BLOBs, or NULL.


*/
typedef struct Mem sqlite3_value;

/*
** CAPI3REF:  SQL Function Context Object {F16001}
**
** The context in which an SQL function executes is stored in an
** sqlite3_context object.  {F16002} A pointer to an sqlite3_context
** object is always first parameter to application-defined SQL functions.
*/
typedef struct sqlite3_context sqlite3_context;

/*
** CAPI3REF:  Binding Values To Prepared Statements {F13500}
**
** {F13501} In the SQL strings input to [sqlite3_prepare_v2()] and its
** variants, literals may be replace by a parameter in one
** of these forms:
**
** <ul>
** <li>  ?
** <li>  ?NNN
** <li>  :AAA
** <li>  @AAA

** [sqlite3_prepare_v2()] or its variants.  {F13503} The second
** argument is the index of the parameter to be set.  {F13504} The
** first parameter has an index of 1.  {F13505} When the same named
** parameter is used more than once, second and subsequent
** occurrences have the same index as the first occurrence. 
** {F13506} The index for named parameters can be looked up using the
** [sqlite3_bind_parameter_name()] API if desired.  {F13507} The index
** for "?NNN" parameters is the value of NNN.
** {F13508} The NNN value must be between 1 and the compile-time
** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999). {END}
** See <a href="limits.html">limits.html</a> for additional information.
**
** {F13509} The third argument is the value to bind to the parameter. {END}
**
** {F13510} In those

int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

/*
** CAPI3REF: Number Of Host Parameters {F13600}
**
** {F13601} Return the largest host parameter index in the precompiled
** statement given as the argument. {F13602} When the host parameters
** are of the forms like ":AAA", "$VVV", "@AAA", or "?",
** then they are assigned sequential increasing numbers beginning
** with one, so the value returned is the number of parameters.
** {F13603} However
** if the same host parameter name is used multiple times, each occurrance
** is given the same number, so the value returned in that case is the number
** of unique host parameter names. {F13604} If host parameters of the
** form "?NNN" are used (where NNN is an integer) then there might be

** CAPI3REF: Name Of A Host Parameter {F13620}
**
** {F13621} This routine returns a pointer to the name of the n-th
** parameter in a [sqlite3_stmt | prepared statement]. {F13622}
** Host parameters of the form ":AAA" or "@AAA" or "$VVV" have a name
** which is the string ":AAA" or "@AAA" or "$VVV". 
** In other words, the initial ":" or "$" or "@"
** is included as part of the name.  {F13626}
** Parameters of the form "?" or "?NNN" have no name.
**
** {F13623} The first host parameter has an index of 1, not 0.
**
** {F13624} If the value n is out of range or if the n-th parameter is
** nameless, then NULL is returned.  {F13625} The returned string is
** always in the UTF-8 encoding even if the named parameter was
** originally specified as UTF-16 in [sqlite3_prepare16()] or
** [sqlite3_prepare16_v2()].
*/

int sqlite3_column_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Column Names In A Result Set {F13720}
**
** {F13721} These routines return the name assigned to a particular column
** in the result set of a SELECT statement.  {F13722} The sqlite3_column_name()
** interface returns a pointer to a zero-terminated UTF8 string
** and sqlite3_column_name16() returns a pointer to a zero-terminated
** UTF16 string. {F13723}  The first parameter is the
** [sqlite3_stmt | prepared statement] that implements the SELECT statement.
** The second parameter is the column number.  The left-most column is
** number 0.
**
** {F13724} The returned string pointer is valid until either the 
** [sqlite3_stmt | prepared statement] is destroyed by [sqlite3_finalize()]
** or until the next call sqlite3_column_name() or sqlite3_column_name16()

const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);

/*
** CAPI3REF: Declared Datatype Of A Query Result {F13760}
**
** The first parameter is a [sqlite3_stmt | compiled SQL statement]. 
** {F13761} 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.  {F13762} If the Nth column of the result set is an
** expression or subquery, then a NULL pointer is returned.
** {F13763} The returned string is always UTF-8 encoded.  {END} 
** For example, in the database schema:
**
** CREATE TABLE t1(c1 VARIANT);

** a [SQLITE_ERROR | error code], or before [sqlite3_step()] has been 
** called on the [sqlite3_stmt | prepared statement] for the first time,
** this routine returns zero.
*/
int sqlite3_data_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Fundamental Datatypes {F10265}
**
** {F10266}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

  void*,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);

/*
** CAPI3REF: Text Encodings {F10267}
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1
#define SQLITE_UTF16LE        2
#define SQLITE_UTF16BE        3

** in the native byte-order of the host machine.  The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF16 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 done.  Otherwise no conversion occurs.  The 
** [SQLITE_INTEGER | datatype] after conversion is returned.
**
** Please pay particular attention to the fact that the pointer that
** is 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.
** Or, if the sqlite3_value* argument comes from the [sqlite3_column_value()]
** interface, then these routines should be called from the same thread
** that ran [sqlite3_column_value()].
**
*/
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtain Aggregate Function Context {F16210}
**
** The implementation of aggregate SQL functions use this routine to allocate
** a structure for storing their state.  
** {F16211} The first time the sqlite3_aggregate_context() routine is
** is called for a particular aggregate, SQLite allocates nBytes of memory
** zeros that memory, and returns a pointer to it.
** {F16212} On second and subsequent calls to sqlite3_aggregate_context()
** for the same aggregate function index, the same buffer is returned. {END}
** The implementation
** of the aggregate can use the returned buffer to accumulate data.
**
** {F16213} SQLite automatically frees the allocated buffer when the aggregate
** query concludes. {END}
**
** The first parameter should be a copy of the 
** [sqlite3_context | SQL function context] that is the first
** parameter to the callback routine that implements the aggregate
** function.
**
** This routine must be called from the same thread in which
** the aggregate SQL function is running.
*/
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

/*
** CAPI3REF: User Data For Functions {F16240}
**
** {F16241} The sqlite3_user_data() interface returns a copy of
** the pointer that was the pUserData parameter (the 5th parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function. {END}

**
** {U16243} This routine must be called from the same thread in which
** the application-defined function is running.
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data {F16270}
**
** The following two functions may be used by scalar SQL functions to
** associate meta-data 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 meta-data may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** meta-data associated with the SQL value passed as the regular expression
** pattern.  The compiled regular expression can be reused on multiple
** invocations of the same function so that the original pattern string
** does not need to be recompiled on each invocation.
**
** {F16271}
** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
** associated by the sqlite3_set_auxdata() function with the Nth argument
** value to the application-defined function.
** {F16272} If no meta-data has been ever been set for the Nth
** argument of the function, or if the cooresponding function parameter
** has changed since the meta-data was set, then sqlite3_get_auxdata()
** returns a NULL pointer.
**
** {F16275} The sqlite3_set_auxdata() interface saves the meta-data
** pointed to by its 3rd parameter as the meta-data for the N-th
** argument of the application-defined function. {END} Subsequent
** calls to sqlite3_get_auxdata() might return this data, if it has
** not been destroyed. 

** {F16277} If it is not NULL, SQLite will invoke the destructor 
** function given by the 4th parameter to sqlite3_set_auxdata() on
** the meta-data when the corresponding function parameter changes
** or when the SQL statement completes, whichever comes first. {END}
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routines must be called from the same thread in which
** the SQL function is running.
*/
void *sqlite3_get_auxdata(sqlite3_context*, int N);
void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior {F10280}
**
** These are special value for the destructor that is passed in as the
** final argument to routines like [sqlite3_result_blob()].  If the destructor

** These functions work very much like the 
** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
** to bind values to host parameters in prepared statements.
** Refer to the
** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
** additional information.
**
** {F16402} 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. 
** {F16403} The sqlite3_result_zeroblob() inerfaces set the result of
** the application defined function to be a BLOB containing all zero
** bytes and N bytes in size, where N is the value of the 2nd parameter.
**
** {F16407} The sqlite3_result_double() interface sets the result from
** an application defined function to be a floating point value specified
** by its 2nd argument.
**
** {F16409} The sqlite3_result_error() and sqlite3_result_error16() functions
** cause the implemented SQL function to throw an exception.
** {F16411} 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. {F16412} SQLite interprets the error
** message string from sqlite3_result_error() as UTF8.  {F16413} SQLite
** interprets the string from sqlite3_result_error16() as UTF16 in native
** byte order.  {F16414} 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.
** {F16415} 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.
** {F16417} The sqlite3_result_error() and sqlite3_result_error16()
** routines make a copy private copy of the error message text before
** they return.  {END} Hence, the calling function can deallocate or
** modify the text after they return without harm.
**
** {F16421} The sqlite3_result_toobig() interface causes SQLite
** to throw an error indicating that a string or BLOB is to long
** to represent.  {F16422} The sqlite3_result_nomem() interface
** causes SQLite to throw an exception indicating that the a
** memory allocation failed.
**
** {F16431} 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.
** {F16432} 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.
**
** {F16437} The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** {F16441} 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.
** {F16442} SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** {F16444} 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.
** {F16447} 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.
** {F16451} 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.
** {F16453} If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_STATIC, then
** SQLite assumes that the text or blob result is constant space and
** does not copy the space or call a destructor when it has
** finished using that result.
** {F16454} 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.
**
** {F16461} The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy the [sqlite3_value]
** object specified by the 2nd parameter.  {F16463} The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
**
** {U16491} These routines are called from within the different thread 
** than the one containing the application-defined function that recieved
** the [sqlite3_context] pointer, the results are undefined.
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
void sqlite3_result_int(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
void sqlite3_result_null(sqlite3_context*);
void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);

/*
** CAPI3REF: Define New Collating Sequences {F16600}
**
** {F16601}
** These functions are used to add new collation sequences to the
** [sqlite3*] handle specified as the first argument. 
**
** {F16602}
** The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
** and a UTF-16 string for sqlite3_create_collation16(). {F16603} In all cases
** the name is passed as the second function argument.
**
** {F16604}
** The third argument may be one of the constants [SQLITE_UTF8],
** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
** routine expects to be passed pointers to strings encoded using UTF-8,
** UTF-16 little-endian or UTF-16 big-endian respectively. {F16605} The
** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that
** the routine expects pointers to 16-bit word aligned strings
** of UTF16 in the native byte order of the host computer.
**
** {F16607}
** A pointer to the user supplied routine must be passed as the fifth
** argument. {F16609} If it is NULL, this is the same as deleting the collation
** sequence (so that SQLite cannot call it anymore).
** {F16611} Each time the application
** supplied function is invoked, it is passed a copy of the void* passed as
** the fourth argument to sqlite3_create_collation() or
** sqlite3_create_collation16() as its first parameter.
**
** {F16612}
** The remaining arguments to the application-supplied routine are two strings,
** each represented by a [length, data] pair and encoded in the encoding
** that was passed as the third argument when the collation sequence was
** registered. {END} The application defined collation routine should
** return negative, zero or positive if
** the first string is less than, equal to, or greater than the second
** string. i.e. (STRING1 - STRING2).
**
** {F16615}
** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
** excapt that it takes an extra argument which is a destructor for
** the collation.  {F16617} The destructor is called when the collation is
** destroyed and is passed a copy of the fourth parameter void* pointer
** of the sqlite3_create_collation_v2().
** {F16618}  Collations are destroyed when
** they are overridden by later calls to the collation creation functions
** or when the [sqlite3*] database handle is closed using [sqlite3_close()].




*/
int sqlite3_create_collation(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)

  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
);

/*
** CAPI3REF: Collation Needed Callbacks {F16700}
**
** {F16701}
** To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** database handle to be called whenever an undefined collation sequence is
** required.
**
** {F16702}
** 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. {F16703} If sqlite3_collation_needed16() is used, the names
** are passed as UTF-16 in machine native byte order. {F16704} A call to either
** function replaces any existing callback.
**
** {F16705} When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16(). {F16706} The second argument is the database
** handle.  {F16707} The third argument is one of [SQLITE_UTF8],
** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most
** desirable form of the collation sequence function required.
** {F16708} The fourth parameter is the name of the
** required collation sequence. {END}
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].
*/
int sqlite3_collation_needed(
  sqlite3*, 

  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** CAPI3REF:  Suspend Execution For A Short Time {F10530}
**
** {F10531} The sqlite3_sleep() function
** causes the current thread to suspend execution
** for at least a number of milliseconds specified in its parameter.
**
** {F10532} If the operating system does not support sleep requests with 
** millisecond time resolution, then the time will be rounded up to 
** the nearest second. {F10533} The number of milliseconds of sleep actually 
** requested from the operating system is returned.
**
** {F10534} SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object. {END}
*/
int sqlite3_sleep(int);

/*
** CAPI3REF:  Name Of The Folder Holding Temporary Files {F10310}
**
** If this global variable is made to point to a string which is

** routines have been call and remain unchanged thereafter.
*/
SQLITE_EXTERN char *sqlite3_temp_directory;

/*
** CAPI3REF:  Test To See If The Database Is In Auto-Commit Mode {F12930}
**
** {F12931} The sqlite3_get_autocommit() interfaces returns non-zero or
** zero if the given database connection is or is not in autocommit mode,
** respectively. {F12932}  Autocommit mode is on
** by default.  {F12933} Autocommit mode is disabled by a BEGIN statement.
** {F12934} Autocommit mode is reenabled by a COMMIT or ROLLBACK. {END}
**
** If certain kinds of errors occur on a statement within a multi-statement
** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR], 
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically.  {F12935} The only way to
** find out if SQLite automatically rolled back the transaction after
** an error is to use this function. {END}
**
** {U12936} If another thread changes the autocommit status of the database
** connection while this routine is running, then the return value
** is undefined. {END}
*/
int sqlite3_get_autocommit(sqlite3*);

/*
** CAPI3REF:  Find The Database Handle Of A Prepared Statement {F13120}
**
** {F13121} The sqlite3_db_handle interface
** returns the [sqlite3*] database handle to which a
** [sqlite3_stmt | prepared statement] belongs.
** {F13122} the database handle returned by sqlite3_db_handle
** is the same database handle that was
** the first argument to the [sqlite3_prepare_v2()] or its variants
** that was used to create the statement in the first place.
*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);


/*
** CAPI3REF: Commit And Rollback Notification Callbacks {F12950}
**
** {F12951} The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** {F12952} Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** {F12953} The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** {F12954} Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** {F12956} The pArg argument is passed through
** to the callback.  {F12957} If the callback on a commit hook function 
** returns non-zero, then the commit is converted into a rollback.
**
** {F12958} If another function was previously registered, its
** pArg value is returned.  Otherwise NULL is returned.
**
** {F12959} Registering a NULL function disables the callback.
**
** {F12961} 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.
** {F12962} The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** {F12964} The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.
** <todo> Check on this </todo> {END}
**
** These are experimental interfaces and are subject to change.
*/
void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

/*
** CAPI3REF: Data Change Notification Callbacks {F12970}
**
** {F12971} 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.
** {F12972} Any callback set by a previous call to this function for the same 
** database connection is overridden.
**
** {F12974} The second argument is a pointer to the function to invoke when a 
** row is updated, inserted or deleted. 
** {F12976} The first argument to the callback is
** a copy of the third argument to sqlite3_update_hook().
** {F12977} 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.
** {F12978} The third and 
** fourth arguments to the callback contain pointers to the database and 
** table name containing the affected row.
** {F12979} The final callback parameter is 
** the rowid of the row.
** {F12981} In the case of an update, this is the rowid after 
** the update takes place.
**
** {F12983} The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).
**
** {F12984} If another function was previously registered, its pArg value
** is returned.  {F12985} Otherwise NULL is returned.
*/
void *sqlite3_update_hook(
  sqlite3*, 
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
  void*
);

/*
** CAPI3REF:  Enable Or Disable Shared Pager Cache {F10330}
**
** {F10331}
** This routine enables or disables the sharing of the database cache
** and schema data structures between connections to the same database.
** {F10332}
** Sharing is enabled if the argument is true and disabled if the argument
** is false.
**
** {F10333} Cache sharing is enabled and disabled
** for an entire process. {END} 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.
**
** {F10334}
** The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** {F10335} Existing database connections continue use the sharing mode
** that was in effect at the time they were opened. {END}
**
** Virtual tables cannot be used with a shared cache.  {F10336} When shared
** cache is enabled, the [sqlite3_create_module()] API used to register
** virtual tables will always return an error. {END}
**
** {F10337} This routine returns [SQLITE_OK] if shared cache was
** enabled or disabled successfully.  {F10338} An [SQLITE_ERROR | error code]
** is returned otherwise. {END}
**
** {F10339} Shared cache is disabled by default. {END} But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
*/
int sqlite3_enable_shared_cache(int);

/*
** CAPI3REF:  Attempt To Free Heap Memory {F17340}
**
** {F17341} The sqlite3_release_memory() interface attempts to
** free N bytes of heap memory by deallocating non-essential memory
** allocations held by the database labrary. {END}  Memory used
** to cache database pages to improve performance is an example of
** non-essential memory.  {F16342} sqlite3_release_memory() returns
** the number of bytes actually freed, which might be more or less
** than the amount requested.
*/
int sqlite3_release_memory(int);

/*
** CAPI3REF:  Impose A Limit On Heap Size {F17350}
**
** {F16351} The sqlite3_soft_heap_limit() interface
** places a "soft" limit on the amount of heap memory that may be allocated
** by SQLite. {F16352} If an internal allocation is requested 
** that would exceed the soft heap limit, [sqlite3_release_memory()] is
** invoked one or more times to free up some space before the allocation
** is made. {END}
**
** {F16353} The limit is called "soft", because if
** [sqlite3_release_memory()] cannot
** free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**
** {F16354}
** A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** {F16355} The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.  
** {F16356} But if the soft heap limit cannot honored, execution will
** continue without error or notification. {END}  This is why the limit is 
** called a "soft" limit.  It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. {F16357} The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. {END}  In
** version 3.5.0 there is no mechanism for limiting the heap usage for
** individual threads.
*/
void sqlite3_soft_heap_limit(int);

/*
** CAPI3REF:  Extract Metadata About A Column Of A Table {F12850}

  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
);

/*
** CAPI3REF: Load An Extension {F12600}
**
** {F12601} The sqlite3_load_extension() interface
** attempts to load an SQLite extension library contained in the file
** zFile. {F12602} The entry point is zProc. {F12603} zProc may be 0
** in which case the name of the entry point defaults
** to "sqlite3_extension_init".
**
** {F12604} The sqlite3_load_extension() interface shall
** return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
**
** {F12605}
** 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()].
** {END}  The calling function should free this memory
** by calling [sqlite3_free()].
**
** {F12606}
** Extension loading must be enabled using [sqlite3_enable_load_extension()]
** prior to calling this API or an error will be returned.
*/
int 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 {F12620}
**
** 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.  {F12622} It is off by default. {END} See ticket #1863.
**
** {F12621} 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. {END}
*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

/*
** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640}
**
** {F12641} This function
** registers an extension entry point that is automatically invoked
** whenever a new database connection is opened using
** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()]. {END}
**
** This API can be invoked at program startup in order to register
** one or more statically linked extensions that will be available
** to all new database connections.
**
** {F12642} Duplicate extensions are detected so calling this routine multiple
** times with the same extension is harmless.
**
** {F12643} This routine stores a pointer to the extension in an array
** that is obtained from sqlite_malloc(). {END} If you run a memory leak
** checker on your program and it reports a leak because of this
** array, then invoke [sqlite3_reset_auto_extension()] prior
** to shutdown to free the memory.
**
** {F12644} Automatic extensions apply across all threads. {END}
**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
*/
int sqlite3_auto_extension(void *xEntryPoint);


/*
** CAPI3REF: Reset Automatic Extension Loading {F12660}
**
** {F12661} This function disables all previously registered
** automatic extensions. {END}  This
** routine undoes the effect of all prior [sqlite3_automatic_extension()]
** calls.
**
** {F12662} This call disabled automatic extensions in all threads. {END}
**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
*/
void sqlite3_reset_auto_extension(void);

** blob in bytes.
*/
typedef struct sqlite3_blob sqlite3_blob;

/*
** CAPI3REF: Open A BLOB For Incremental I/O {F17810}
**
** {F17811} This interfaces opens a 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> {END}
**
** {F17812} If the flags parameter is non-zero, the blob is opened for 
** read and write access. If it is zero, the blob is opened for read 
** access. {END}
**
** {F17813} On success, [SQLITE_OK] is returned and the new 
** [sqlite3_blob | blob handle] is written to *ppBlob. 
** {F17814} Otherwise an error code is returned and 
** any value written to *ppBlob should not be used by the caller.
** {F17815} This function sets the database-handle error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
** <todo>We should go through and mark all interfaces that behave this
** way with a similar statement</todo>
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
  int flags,
  sqlite3_blob **ppBlob
);

/*
** CAPI3REF:  Close A BLOB Handle {F17830}
**
** Close an open [sqlite3_blob | blob handle].
**
** {F17831} Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in autocommit mode.
** {F17832} If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit. {END}
** Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  {F17833} Any errors that occur during
** closing are reported as a non-zero return value.
**
** {F17839} The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.
*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF:  Return The Size Of An Open BLOB {F17805}
**
** {F16806} Return the size in bytes of the blob accessible via the open 
** [sqlite3_blob | blob-handle] passed as an argument.
*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF:  Read Data From A BLOB Incrementally {F17850}
**
** This function is used to read data from an open 
** [sqlite3_blob | blob-handle] into a caller supplied buffer.
** {F17851} n bytes of data are copied into buffer
** z from the open blob, starting at offset iOffset.
**
** {F17852} If offset iOffset is less than n bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is read.  {F17853} If n is
** less than zero [SQLITE_ERROR] is returned and no data is read.
**
** {F17854} On success, SQLITE_OK is returned. Otherwise, an 
** [SQLITE_ERROR | SQLite error code] or an
** [SQLITE_IOERR_READ | extended error code] is returned.
*/
int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset);

/*
** CAPI3REF:  Write Data Into A BLOB Incrementally {F17870}
**
** This function is used to write data into an open 
** [sqlite3_blob | blob-handle] from a user supplied buffer.
** {F17871} n bytes of data are copied from the buffer
** pointed to by z into the open blob, starting at offset iOffset.
**
** {F17872} If the [sqlite3_blob | 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].
**
** {F17873} This function may only modify the contents of the blob; it is
** not possible to increase the size of a blob using this API.
** {F17874} If offset iOffset is less than n bytes from the end of the blob, 
** [SQLITE_ERROR] is returned and no data is written.  {F17875} If n is
** less than zero [SQLITE_ERROR] is returned and no data is written.
**
** {F17876} On success, SQLITE_OK is returned. Otherwise, an 
** [SQLITE_ERROR | SQLite error code] or an
** [SQLITE_IOERR_READ | extended error code] is returned.
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF:  Virtual File System Objects {F11200}
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system.  Most 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.
**
** {F11201} The sqlite3_vfs_find() interface returns a pointer to 
** a VFS given its name.  {F11202} Names are case sensitive.
** {F11203} Names are zero-terminated UTF-8 strings.
** {F11204} If there is no match, a NULL
** pointer is returned. {F11205} If zVfsName is NULL then the default 
** VFS is returned. {END}
**
** {F11210} New VFSes are registered with sqlite3_vfs_register().
** {F11211} Each new VFS becomes the default VFS if the makeDflt flag is set.
** {F11212} The same VFS can be registered multiple times without injury.
** {F11213} To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set. {U11214} If two different VFSes with the
** same name are registered, the behavior is undefined.  {U11215} If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
** 
** {F11220} Unregister a VFS with the sqlite3_vfs_unregister() interface.
** {F11221} If the default VFS is unregistered, another VFS is chosen as
** the default.  The choice for the new VFS is arbitrary.
*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);

/*

** implementation is included with the library.  The
** mutex interface routines defined here become external
** references in the SQLite library for which implementations
** must be provided by the application.  This facility allows an
** application that links against SQLite to provide its own mutex
** implementation without having to modify the SQLite core.
**
** {F17011} The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. {F17012} If it returns NULL
** that means that a mutex could not be allocated. {F17013} SQLite
** will unwind its stack and return an error. {F17014} The argument
** to sqlite3_mutex_alloc() is 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_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** </ul> {END}
**
** {F17015} The first two constants 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. {END}
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  {F17016} But SQLite will only request a recursive mutex in
** cases where it really needs one.  {END} 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.
**
** {F17017} The other allowed parameters to sqlite3_mutex_alloc() each return
** a pointer to a static preexisting mutex. {END}  Four 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.
**
** {F17018} 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.  {F17034} But for the static 
** mutex types, the same mutex is returned on every call that has
** the same type number. {END}
**
** {F17019} The sqlite3_mutex_free() routine deallocates a previously
** allocated dynamic mutex. {F17020} SQLite is careful to deallocate every
** dynamic mutex that it allocates. {U17021} The dynamic mutexes must not be in 
** use when they are deallocated. {U17022} Attempting to deallocate a static
** mutex results in undefined behavior. {F17023} SQLite never deallocates
** a static mutex. {END}
**
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex. {F17024} If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY. {F17025}  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  {F17026} Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** {F17027} In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  {U17028} If the same thread tries to enter any other
** kind of mutex more than once, the behavior is undefined.
** {F17029} SQLite will never exhibit
** such behavior in its own use of mutexes. {END}
**
** Some systems (ex: windows95) do not the operation implemented by
** sqlite3_mutex_try().  On those systems, sqlite3_mutex_try() will
** always return SQLITE_BUSY.  {F17030} The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable behavior. {END}
**
** {F17031} The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  {U17032} The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.  {F17033} SQLite will
** never do either. {END}
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
sqlite3_mutex *sqlite3_mutex_alloc(int);
void sqlite3_mutex_free(sqlite3_mutex*);
void sqlite3_mutex_enter(sqlite3_mutex*);
int sqlite3_mutex_try(sqlite3_mutex*);
void sqlite3_mutex_leave(sqlite3_mutex*);

/*
** CAPI3REF: Mutex Verifcation Routines {F17080}
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements. {F17081} The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core.  {F17082} The core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag.  {U17087} External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** {F17083} These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread. {END}
**
** {X17084} The implementation is not required to provided versions of these

** are passed directly through to the second and third parameters of
** the xFileControl method.  {F11305} The return value of the xFileControl
** method becomes the return value of this routine.
**
** {F11306} If the second parameter (zDbName) does not match the name of any
** open database file, then SQLITE_ERROR is returned. {F11307} This error
** code is not remembered and will not be recalled by [sqlite3_errcode()]
** or [sqlite3_errmsg()]. {U11308} The underlying xFileControl method might
** also return SQLITE_ERROR.  {U11309} There is no way to distinguish between
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
** xFileControl method. {END}
**
** See also: [SQLITE_FCNTL_LOCKSTATE]
*/
int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);