** 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 1.343 2008/06/21 06:16:43 mihailim 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++.
................................................................................
** 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.</dd>
**
** <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The argument specifics
** alternative low-level memory allocation routines to be used in place
** the memory allocation routines built into SQLite.</dd>
**
** <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd>This 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
................................................................................
** <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd>This option specifies a static memory buffer that SQLite can use for
** scratch memory.  There are three arguments:  A pointer to the memory, the
** size of each scratch buffer (sz), and the number of buffers (N).  The sz
** argument must be a multiple of 16. The first
** argument should point to an allocation of at least (sz+4)*N bytes of memory.
** SQLite will use no more than one scratch buffer at once per thread, so
** N should be set to the expected maximum number of threads.  The sz 
** parameter should be 6 times the size of the largest database page size.
** Scratch buffers are used as part of the btree balance operation.  If
** The btree balancer needs additional memory beyond what is provided by
** scratch buffers or if no scratch buffer space is specified, then SQLite
** goes to [sqlite3_malloc()] to obtain the memory it needs.
** </dd>
**
** <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd>This option specifies a static memory buffer that SQLite can use for
** the database page cache.  There are three arguments:
** A pointer to the memory, the
** size of each page buffer (sz), and the number of pages (N).  The sz
** argument must be a power of two between 512 and 32768.  The first
** argument should point to an allocation of at least (sz+4)*N bytes of memory.
** SQLite will use the memory provided by the first argument to satisfy
** its memory needs for the first N pages that it adds to cache.  If 
** additional page cache memory is needed beyond what is provided by
** this option, then SQLite goes to [sqlite3_malloc()] for the additional
** storage space.
** </dd>
**
** <dt>SQLITE_CONFIG_HEAP</dt>
** <dd>This 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].
** There are three arguments: A pointer to the memory, the number of
** bytes in the memory buffer, and the minimum allocation size.  When
** this configuration option is used, SQLite never calls the system
** malloc() implementation but instead uses the supplied memory buffer
** to satisfy all [sqlite3_malloc()] requests.
** </dd>
**
** <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The argument specifics
** alternative low-level mutex routines to be used in place
** the mutex routines built into SQLite.</dd>
**
** <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The
** [sqlite3_mutex_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* */


/*
** CAPI3REF: Enable Or Disable Extended Result Codes {F12200}
**
** The sqlite3_extended_result_codes() routine enables or disables the
** [SQLITE_IOERR_READ | extended result codes] feature of SQLite.
** The extended result codes are disabled by default for historical
** compatibility.
**
** INVARIANTS:
**
** {F12201} Each new [database connection] shall have the 
**          [extended result codes] feature
**          disabled by default.
**
** {F12202} The [sqlite3_extended_result_codes(D,F)] interface shall enable
**          [extended result codes] for the 
**          [database connection] D if the F parameter
**          is true, or disable them if F is false.
*/
int sqlite3_extended_result_codes(sqlite3*, int onoff);

/*
** CAPI3REF: Last Insert Rowid {F12220}
**
** Each entry in an SQLite table has a unique 64-bit signed
................................................................................
** integer key called the "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.
**
** This routine returns the rowid of the most recent
** successful INSERT into the database from the database connection
** shown in the first argument.  If no successful inserts
** have ever occurred on this database connection, zero is returned.
**
** If an INSERT occurs within a trigger, then the rowid of the
** inserted row is returned by this routine as long as the trigger
** is running.  But once the trigger terminates, the value returned
** by this routine reverts to the last value inserted before the
** trigger fired.
**
** 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.
**
** INVARIANTS:
**
** {F12221} The [sqlite3_last_insert_rowid()] function returns the
**          rowid of the most recent successful insert done
**          on the same database connection and within the same
**          or higher level trigger context, or zero if there have
**          been no qualifying inserts.
**
** {F12223} The [sqlite3_last_insert_rowid()] function returns
**          same value when called from the same trigger context
**          immediately before and after a ROLLBACK.
**
** LIMITATIONS:
**
** {U12232} If a separate thread does 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.
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified {F12240}
**
** This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the connection specified by the first parameter.  Only
** changes that are directly specified by the INSERT, UPDATE, or
** DELETE statement are counted.  Auxiliary changes caused by
** triggers are not counted. Use the [sqlite3_total_changes()] function
** to find the total number of changes including changes caused by triggers.
**
** A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of REPLACE constraint resolution,
** rollback, ABORT processing, DROP TABLE, or by any other
................................................................................
** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
** not create a new trigger context.
**
** This function returns the number of direct row changes in the
** most recent INSERT, UPDATE, or DELETE statement within the same
** trigger context.
**
** So when called from the top level, this function returns the
** number of changes in the most recent INSERT, UPDATE, or DELETE
** that also occurred at the top level.
** 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.
** However, the number returned does not include in changes
** caused by subtriggers since they have their own context.
**
** 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 from the
** table.)  Because of this optimization, the deletions in
** "DELETE FROM table" are not row changes and will not be counted
** by the sqlite3_changes() or [sqlite3_total_changes()] functions.

** To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
**
** INVARIANTS:
**
** {F12241} The [sqlite3_changes()] function shall return the number of
**          row changes caused by the most recent INSERT, UPDATE,
**          or DELETE statement on the same database connection and
**          within the same or higher trigger context, or zero if there have
**          not been any qualifying row changes.
**
** {F12243} Statements of the form "DELETE FROM tablename" with no
**          WHERE clause shall cause subsequent calls to 
**          [sqlite3_changes()] to return zero, regardless of the
**          number of rows originally in the table.
**
** LIMITATIONS:
**
** {U12252} 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.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified {F12260}
***
** This function returns the number of row changes caused
** by INSERT, UPDATE or DELETE statements since the database handle
** was opened.  The count includes all changes from all trigger
** contexts.  But the count does not include changes used to
** implement REPLACE constraints, do rollbacks or ABORT processing,
** or DROP table processing.
** The 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()]).
**
** 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 from 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.
**
** See also the [sqlite3_changes()] interface.
**
** INVARIANTS:
** 
** {F12261} The [sqlite3_total_changes()] returns the total number
**          of row changes caused by INSERT, UPDATE, and/or DELETE
**          statements on the same [database connection], in any
**          trigger context, since the database connection was
**          created.
**
** {F12263} Statements of the form "DELETE FROM tablename" with no
**          WHERE clause shall not change the value returned
**          by [sqlite3_total_changes()]
**
** LIMITATIONS:
**
** {U12264} 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.
*/
................................................................................
int sqlite3_total_changes(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query {F12270}
**
** 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 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.

** 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.

** A call to sqlite3_interrupt() has no effect on SQL statements
** that are started after sqlite3_interrupt() returns.
**
** INVARIANTS:
**
** {F12271} The [sqlite3_interrupt()] interface will force all running
**          SQL statements associated with the same database connection
**          to halt after processing at most one additional row of
**          data.
**
** {F12272} Any SQL statement that is interrupted by [sqlite3_interrupt()]
**          will return [SQLITE_INTERRUPT].
**
** LIMITATIONS:
**
** {U12279} If the database connection closes while [sqlite3_interrupt()]
................................................................................
** 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 fragment of a
** 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.
**
** These routines do not parse the SQL and
** so will not detect syntactically incorrect SQL.
**
** INVARIANTS:
**
** {F10511} The sqlite3_complete() and sqlite3_complete16() functions
**          return true (non-zero) if and only if the last
**          non-whitespace token in their input is a semicolon that
**          is not in between the BEGIN and END of a CREATE TRIGGER
**          statement.
**
** LIMITATIONS:
**
** {U10512} The input to sqlite3_complete() must be a zero-terminated
**          UTF-8 string.
**
** {U10513} The input to sqlite3_complete16() must be a zero-terminated
................................................................................
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310}
**
** 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.

** If the busy callback is NULL, then [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock.
** If the busy callback is not NULL, then the
** callback will be invoked with two arguments.  The

** first argument to the handler is a copy of the void* pointer which
** is the third argument to this routine.  The second argument to
** the handler is the number of times that the busy handler has
** been invoked for this locking event.   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.
** 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.
** 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.
** 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,
................................................................................
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent
** readers.  If it is unable to promote the lock, then the in-memory
** cache will be left in an inconsistent state and so the error
** code is promoted from the relatively benign [SQLITE_BUSY] to
** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
** forces an automatic rollback of the changes.  See the
** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError">
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
** this is important.
**	
** There can only be a single busy handler defined for each database
** connection.  Setting a new busy handler clears any previous one. 
** Note that calling [sqlite3_busy_timeout()] will also set or clear
** the busy handler.
**
** INVARIANTS:
**
** {F12311} The [sqlite3_busy_handler()] function replaces the busy handler
**          callback in the database connection identified by the 1st
**          parameter with a new busy handler identified by the 2nd and 3rd
**          parameters.
**
** {F12312} The default busy handler for new database connections is NULL.
**
** {F12314} When two or more database connection share a [sqlite3_enable_shared_cache | common cache],

**          the busy handler for the database connection currently using
**          the cache is invoked when the cache encounters a lock.
**
** {F12316} If a busy handler callback returns zero, then the SQLite
**          interface that provoked the locking event will return
**          [SQLITE_BUSY].
**
** {F12318} SQLite will invokes the busy handler with two arguments which
**          are a copy of the pointer supplied by the 3rd parameter to
**          [sqlite3_busy_handler()] and a count of the number of prior
**          invocations of the busy handler for the same locking event.
**
** LIMITATIONS:
**
** {U12319} A busy handler should not call close the database connection
**          or prepared statement that invoked the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout {F12340}
**
** This routine sets a [sqlite3_busy_handler | busy handler]
** that sleeps for a while when a
** table is locked.  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].
**
** 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.  If another busy handler was defined  
** (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.
**
** INVARIANTS:
**
** {F12341} The [sqlite3_busy_timeout()] function overrides any prior
**          [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting
**          on the same database connection.
................................................................................
** 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 are give a NULL pointer.  All other values are in
** their UTF-8 zero-terminated string representation as returned by
** [sqlite3_column_text()].
**
** A result table might consists 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>
................................................................................
** </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.  It returns a result table to the
** pointer given in its 3rd parameter.
**
** After the calling function has finished using the result, it should 
** pass the pointer to the result table 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()].
**
** INVARIANTS:
**
** {F12371} If a [sqlite3_get_table()] fails a memory allocation, then
**          it frees the result table under construction, aborts the
**          query in process, skips any subsequent queries, sets the
**          *resultp output pointer to NULL and returns [SQLITE_NOMEM].
**
** {F12373} If the ncolumn parameter to [sqlite3_get_table()] is not NULL
**          then [sqlite3_get_table()] write the number of columns in the
**          result set of the query into *ncolumn if the query is
**          successful (if the function returns SQLITE_OK).
**
** {F12374} If the nrow parameter to [sqlite3_get_table()] is not NULL
**          then [sqlite3_get_table()] write the number of rows in the
**          result set of the query into *nrow if the query is
**          successful (if the function returns SQLITE_OK).
**
** {F12376} The [sqlite3_get_table()] function sets its *ncolumn value
**          to the number of columns in the result set of the query in the
**          sql parameter, or to zero if the query in sql has an empty
**          result set.
*/
int sqlite3_get_table(
  sqlite3*,             /* An open database */
  const char *sql,      /* SQL to be evaluated */
  char ***pResult,      /* Results of the query */
  int *nrow,            /* Number of result rows written here */
  int *ncolumn,         /* Number of result columns written here */
................................................................................
**
** The %q option works like %s in that it substitutes a null-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, so some string variable 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:
**
................................................................................
** 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.  Or if the parameter in the argument
** list is a NULL pointer, %Q substitutes the text "NULL" (without single
** quotes) in place of the %Q option. {END}  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>
**
................................................................................
**           memory obtained from [sqlite3_malloc()] or NULL pointers if
**           a call to [sqlite3_malloc()] fails.
**
** {F17406}  The [sqlite3_snprintf()] interface writes a zero-terminated
**           UTF-8 string into the buffer pointed to by the second parameter
**           provided that the first parameter is greater than zero.
**
** {F17407}  The [sqlite3_snprintf()] interface does not writes slots of
**           its output buffer (the second parameter) outside the range
**           of 0 through N-1 (where N is the first parameter)
**           regardless of the length of the string
**           requested by the format specification.
**   
*/
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
char *sqlite3_snprintf(int,char*,const char*, ...);

/*
** CAPI3REF: Memory Allocation Subsystem {F17300}
................................................................................
** second parameter.  The memory allocation to be resized is the first
** parameter.  If the first parameter to sqlite3_realloc()
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
** If the second parameter to sqlite3_realloc() is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
** Sqlite3_realloc() returns a pointer to a memory allocation
** of at least N bytes in size or NULL if sufficient memory is unavailable.
** 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.
** If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary. {END}
**
** 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].
**
** INVARIANTS:
**
** {F17303}  The [sqlite3_malloc(N)] interface returns either a pointer to 
**           newly checked-out block of at least N bytes of memory
**           that is 8-byte aligned, 
**           or it returns NULL if it is unable to fulfill the request.
**
** {F17304}  The [sqlite3_malloc(N)] interface returns a NULL pointer if
**           N is less than or equal to zero.
**
** {F17305}  The [sqlite3_free(P)] interface releases memory previously
**           returned from [sqlite3_malloc()] or [sqlite3_realloc()],
**           making it available for reuse.
................................................................................
**           deallocation needs.
**
** {F17318}  The [sqlite3_realloc(P,N)] interface returns either a pointer
**           to a block of checked-out memory of at least N bytes in size
**           that is 8-byte aligned, or a NULL pointer.
**
** {F17321}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
**           copies the first K bytes of content from P into the newly allocated
**           where K is the lesser of N and the size of the buffer P.

**
** {F17322}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
**           releases the buffer P.
**
** {F17323}  When [sqlite3_realloc(P,N)] returns NULL, the buffer P is
**           not modified or released.
**
** LIMITATIONS:
**
** {U17350}  The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
**           must be either NULL or else a pointer obtained from a prior
**           invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that has
**           not been released.
**
** {U17351}  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()].
**
*/
void *sqlite3_malloc(int);
void *sqlite3_realloc(void*, int);
void sqlite3_free(void*);

/*
** CAPI3REF: Memory Allocator Statistics {F17370}
**
** SQLite provides these two interfaces for reporting on the status
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
** the memory allocation subsystem included within the SQLite.
**
** INVARIANTS:
**
** {F17371} The [sqlite3_memory_used()] routine returns the
**          number of bytes of memory currently outstanding 
**          (malloced but not freed).
**
** {F17373} The [sqlite3_memory_highwater()] routine returns the maximum
**          value of [sqlite3_memory_used()] 
**          since the high-water mark was last reset.
**
** {F17374} 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.
** 

** 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 1.344 2008/06/21 11:20:48 mihailim 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++.
................................................................................
** 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.</dd>
**
** <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd>This 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.</dd>
**
** <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd>This 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
................................................................................
** <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd>This option specifies a static memory buffer that SQLite can use for
** scratch memory.  There are three arguments:  A pointer to the memory, the
** size of each scratch buffer (sz), and the number of buffers (N).  The sz
** argument must be a multiple of 16. The first
** argument should point to an allocation of at least (sz+4)*N bytes of memory.
** SQLite will use no more than one scratch buffer at once per thread, so
** N should be set to the expected maximum number of threads.  The sz
** parameter should be 6 times the size of the largest database page size.
** Scratch buffers are used as part of the btree balance operation.  If
** The btree balancer needs additional memory beyond what is provided by
** scratch buffers or if no scratch buffer space is specified, then SQLite
** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd>

**
** <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd>This option specifies a static memory buffer that SQLite can use for
** the database page cache.  There are three arguments: A pointer to the

** memory, the size of each page buffer (sz), and the number of pages (N).
** The sz argument must be a power of two between 512 and 32768.  The first
** argument should point to an allocation of at least (sz+4)*N bytes of memory.
** SQLite will use the memory provided by the first argument to satisfy its
** memory needs for the first N pages that it adds to cache.  If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd>


**
** <dt>SQLITE_CONFIG_HEAP</dt>
** <dd>This 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].
** There are three arguments: A pointer to the memory, the number of
** bytes in the memory buffer, and the minimum allocation size.  When
** this configuration option is used, SQLite never calls the system
** malloc() implementation but instead uses the supplied memory buffer
** to satisfy all [sqlite3_malloc()] requests.</dd>

**
** <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd>This 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.</dd>
**
** <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The
** [sqlite3_mutex_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* */


/*
** CAPI3REF: Enable Or Disable Extended Result Codes {F12200}
**
** The sqlite3_extended_result_codes() routine enables or disables the
** [SQLITE_IOERR_READ | extended result codes] feature of SQLite.
** The extended result codes are disabled by default for historical
** compatibility considerations.
**
** INVARIANTS:
**
** {F12201} Each new [database connection] shall have the
**          [extended result codes] feature disabled by default.

**
** {F12202} The [sqlite3_extended_result_codes(D,F)] interface shall enable
**          [extended result codes] for the  [database connection] D

**          if the F parameter is true, or disable them if F is false.
*/
int sqlite3_extended_result_codes(sqlite3*, int onoff);

/*
** CAPI3REF: Last Insert Rowid {F12220}
**
** Each entry in an SQLite table has a unique 64-bit signed
................................................................................
** integer key called the "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.
**
** This routine returns the rowid of the most recent
** successful INSERT into the database from the [database connection]
** in the first argument.  If no successful INSERTs
** have ever occurred on that database connection, zero is returned.
**
** If an INSERT occurs within a trigger, then the rowid of the inserted
** row is returned by this routine as long as the trigger is running.
** But once the trigger terminates, the value returned by this routine
** reverts to the last value inserted before the trigger fired.

**
** 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.
**
** INVARIANTS:
**
** {F12221} The [sqlite3_last_insert_rowid()] function returns the rowid
**          of the most recent successful INSERT performed on the same
**          [database connection] and within the same or higher level
**          trigger context, or zero if there have been no qualifying inserts.

**
** {F12223} The [sqlite3_last_insert_rowid()] function returns the
**          same value when called from the same trigger context
**          immediately before and after a ROLLBACK.
**
** LIMITATIONS:
**
** {U12232} 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.
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified {F12240}
**
** This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the [database connection] specified by the first parameter.
** Only changes that are directly specified by the INSERT, UPDATE,
** or DELETE statement are counted.  Auxiliary changes caused by
** triggers are not counted. Use the [sqlite3_total_changes()] function
** to find the total number of changes including changes caused by triggers.
**
** A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of REPLACE constraint resolution,
** rollback, ABORT processing, DROP TABLE, or by any other
................................................................................
** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
** not create a new trigger context.
**
** This function returns the number of direct row changes in the
** most recent INSERT, UPDATE, or DELETE statement within the same
** trigger context.
**
** Thus, when called from the top level, this function returns the
** number of changes in the most recent INSERT, UPDATE, or DELETE
** that also occurred at the top level.  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.
** However, the number returned does not include changes
** caused by subtriggers since those have their own context.
**
** 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 from the table.)  Because of this

** optimization, the deletions in "DELETE FROM table" are not row changes and
** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()]
** functions, 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.
**
** INVARIANTS:
**
** {F12241} The [sqlite3_changes()] function shall return the number of
**          row changes caused by the most recent INSERT, UPDATE,
**          or DELETE statement on the same database connection and
**          within the same or higher trigger context, or zero if there have
**          not been any qualifying row changes.
**
** {F12243} Statements of the form "DELETE FROM tablename" with no
**          WHERE clause shall cause subsequent calls to
**          [sqlite3_changes()] to return zero, regardless of the
**          number of rows originally in the table.
**
** LIMITATIONS:
**
** {U12252} 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.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified {F12260}
**
** This function returns the number of row changes caused by INSERT,
** UPDATE or DELETE statements since the [database connection] was opened.
** The count includes all changes from all trigger contexts.  However,
** the count does not include changes used to implement REPLACE constraints,
** do rollbacks or ABORT processing, or DROP table processing.


** The 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()]).
**
** 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 from the table.)  Because of this

** optimization, the deletions in "DELETE FROM table" are not row changes and
** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()]
** functions, 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.
**
** See also the [sqlite3_changes()] interface.
**
** INVARIANTS:
**
** {F12261} The [sqlite3_total_changes()] returns the total number
**          of row changes caused by INSERT, UPDATE, and/or DELETE
**          statements on the same [database connection], in any
**          trigger context, since the database connection was created.

**
** {F12263} Statements of the form "DELETE FROM tablename" with no
**          WHERE clause shall not change the value returned
**          by [sqlite3_total_changes()].
**
** LIMITATIONS:
**
** {U12264} 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.
*/
................................................................................
int sqlite3_total_changes(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query {F12270}
**
** This function causes any pending database operation to abort and
** return at its earliest opportunity. This routine is typically
** called in response to an 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.
**
** A call to sqlite3_interrupt() has no effect on SQL statements
** that are started after sqlite3_interrupt() returns.
**
** INVARIANTS:
**
** {F12271} The [sqlite3_interrupt()] interface will force all running
**          SQL statements associated with the same database connection
**          to halt after processing at most one additional row of data.

**
** {F12272} Any SQL statement that is interrupted by [sqlite3_interrupt()]
**          will return [SQLITE_INTERRUPT].
**
** LIMITATIONS:
**
** {U12279} If the database connection closes while [sqlite3_interrupt()]
................................................................................
** 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 fragment of a
** 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.
**
** These routines do not parse the SQL statements thus
** will not detect syntactically incorrect SQL.
**
** INVARIANTS:
**
** {F10511} The sqlite3_complete() and sqlite3_complete16() functions
**          return true (non-zero) if and only if the last non-whitespace
**          token in their input is a semicolon that is not in between
**          the BEGIN and END of a CREATE TRIGGER statement.

**
** LIMITATIONS:
**
** {U10512} The input to sqlite3_complete() must be a zero-terminated
**          UTF-8 string.
**
** {U10513} The input to sqlite3_complete16() must be a zero-terminated
................................................................................
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310}
**
** This routine sets a callback function that might be invoked whenever
** an attempt is made to open a database table that another thread
** or process has locked.
**
** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]

** is returned immediately upon encountering the lock. If the busy callback

** is not NULL, then the callback will be invoked with two arguments.
**
** The first argument to the handler is a copy of the void* pointer which
** is the third argument to sqlite3_busy_handler().  The second argument to
** the handler callback is the number of times that the busy handler has
** been invoked for this locking event.  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.
** 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. 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.

** 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,
................................................................................
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent
** readers.  If it is unable to promote the lock, then the in-memory
** cache will be left in an inconsistent state and so the error
** code is promoted from the relatively benign [SQLITE_BUSY] to
** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
** forces an automatic rollback of the changes.  See the
** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
** this is important.
**
** 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()]
** will also set or clear the busy handler.
**
** INVARIANTS:
**
** {F12311} The [sqlite3_busy_handler()] function replaces the busy handler
**          callback in the database connection identified by the 1st
**          parameter with a new busy handler identified by the 2nd and 3rd
**          parameters.
**
** {F12312} The default busy handler for new database connections is NULL.
**
** {F12314} When two or more database connection share a
**          [sqlite3_enable_shared_cache | common cache],
**          the busy handler for the database connection currently using
**          the cache is invoked when the cache encounters a lock.
**
** {F12316} If a busy handler callback returns zero, then the SQLite interface
**          that provoked the locking event will return [SQLITE_BUSY].

**
** {F12318} SQLite will invokes the busy handler with two arguments which
**          are a copy of the pointer supplied by the 3rd parameter to
**          [sqlite3_busy_handler()] and a count of the number of prior
**          invocations of the busy handler for the same locking event.
**
** LIMITATIONS:
**
** {U12319} A busy handler should not close the database connection
**          or [prepared statement] that invoked the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout {F12340}
**
** 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. {F12343} After "ms" milliseconds of sleeping,
** the handler returns 0 which causes [sqlite3_step()] to return
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** 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] any any given moment.  If another busy handler
** was defined  (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.
**
** INVARIANTS:
**
** {F12341} The [sqlite3_busy_timeout()] function overrides any prior
**          [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting
**          on the same database connection.
................................................................................
** 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>
................................................................................
** </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.  It returns a result table to the
** pointer given in its 3rd parameter.
**
** After the calling function has finished using the result, it should
** pass the pointer to the result table 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()].

**
** INVARIANTS:
**
** {F12371} If a [sqlite3_get_table()] fails a memory allocation, then
**          it frees the result table under construction, aborts the
**          query in process, skips any subsequent queries, sets the
**          *resultp output pointer to NULL and returns [SQLITE_NOMEM].
**
** {F12373} If the ncolumn parameter to [sqlite3_get_table()] is not NULL
**          then [sqlite3_get_table()] writes the number of columns in the
**          result set of the query into *ncolumn if the query is
**          successful (if the function returns SQLITE_OK).
**
** {F12374} If the nrow parameter to [sqlite3_get_table()] is not NULL
**          then [sqlite3_get_table()] writes the number of rows in the
**          result set of the query into *nrow if the query is
**          successful (if the function returns SQLITE_OK).
**
** {F12376} The [sqlite3_get_table()] function sets its *ncolumn value to the
**          number of columns in the result set of the query in the sql
**          parameter, or to zero if the query in sql has an empty result set.

*/
int sqlite3_get_table(
  sqlite3*,             /* An open database */
  const char *sql,      /* SQL to be evaluated */
  char ***pResult,      /* Results of the query */
  int *nrow,            /* Number of result rows written here */
  int *ncolumn,         /* Number of result columns written here */
................................................................................
**
** The %q option works like %s in that it substitutes a null-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:
**
................................................................................
** 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) in place of the %Q option. {END}  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>
**
................................................................................
**           memory obtained from [sqlite3_malloc()] or NULL pointers if
**           a call to [sqlite3_malloc()] fails.
**
** {F17406}  The [sqlite3_snprintf()] interface writes a zero-terminated
**           UTF-8 string into the buffer pointed to by the second parameter
**           provided that the first parameter is greater than zero.
**
** {F17407}  The [sqlite3_snprintf()] interface does not write slots of
**           its output buffer (the second parameter) outside the range
**           of 0 through N-1 (where N is the first parameter)
**           regardless of the length of the string
**           requested by the format specification.

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

/*
** CAPI3REF: Memory Allocation Subsystem {F17300}
................................................................................
** second parameter.  The memory allocation to be resized is the first
** parameter.  If the first parameter to sqlite3_realloc()
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
** If the second parameter to sqlite3_realloc() is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
** sqlite3_realloc() returns a pointer to a memory allocation
** of at least N bytes in size or NULL if sufficient memory is unavailable.
** 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.
** If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary. {END}
**
** 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

** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i>

** is an integer), then SQLite create a static array of at least
** <i>NNN</i> bytes in size and uses 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].
**
** INVARIANTS:
**
** {F17303}  The [sqlite3_malloc(N)] interface returns either a pointer to
**           a newly checked-out block of at least N bytes of memory
**           that is 8-byte aligned, or it returns NULL if it is unable
**           to fulfill the request.
**
** {F17304}  The [sqlite3_malloc(N)] interface returns a NULL pointer if
**           N is less than or equal to zero.
**
** {F17305}  The [sqlite3_free(P)] interface releases memory previously
**           returned from [sqlite3_malloc()] or [sqlite3_realloc()],
**           making it available for reuse.
................................................................................
**           deallocation needs.
**
** {F17318}  The [sqlite3_realloc(P,N)] interface returns either a pointer
**           to a block of checked-out memory of at least N bytes in size
**           that is 8-byte aligned, or a NULL pointer.
**
** {F17321}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
**           copies the first K bytes of content from P into the newly
**           allocated block, where K is the lesser of N and the size of
**           the buffer P.
**
** {F17322}  When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
**           releases the buffer P.
**
** {F17323}  When [sqlite3_realloc(P,N)] returns NULL, the buffer P is
**           not modified or released.
**
** LIMITATIONS:
**
** {U17350}  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.
**
** {U17351}  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()].

*/
void *sqlite3_malloc(int);
void *sqlite3_realloc(void*, int);
void sqlite3_free(void*);

/*
** CAPI3REF: Memory Allocator Statistics {F17370}
**
** 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.
**
** INVARIANTS:
**
** {F17371} The [sqlite3_memory_used()] routine returns the
**          number of bytes of memory currently outstanding 
**          (malloced but not freed).
**
** {F17373} The [sqlite3_memory_highwater()] routine returns the maximum
**          value of [sqlite3_memory_used()] since the high-water mark
**          was last reset.
**
** {F17374} 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.
**