SQLite TEA

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.62 for sqlite 3.6.3.
# Generated by GNU Autoconf 2.62 for sqlite 3.6.5.
#
# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
# 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.
## --------------------- ##
## M4sh Initialization.  ##

MFLAGS=
MAKEFLAGS=
SHELL=${CONFIG_SHELL-/bin/sh}

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.6.3'
PACKAGE_STRING='sqlite 3.6.3'
PACKAGE_VERSION='3.6.5'
PACKAGE_STRING='sqlite 3.6.5'
PACKAGE_BUGREPORT=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>

#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.6.3 to adapt to many kinds of systems.
\`configure' configures sqlite 3.6.5 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

  cat <<\_ACEOF
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.6.3:";;
     short | recursive ) echo "Configuration of sqlite 3.6.5:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]

    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.6.3
sqlite configure 3.6.5
generated by GNU Autoconf 2.62

Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit
fi
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.6.3, which was
It was created by sqlite $as_me 3.6.5, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{

exec 6>&1

# Save the log message, to keep $[0] and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.6.3, which was
This file was extended by sqlite $as_me 3.6.5, which was
generated by GNU Autoconf 2.62.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@

$config_files

Report bugs to <bug-autoconf@gnu.org>."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_version="\\
sqlite config.status 3.6.3
sqlite config.status 3.6.5
configured by $0, generated by GNU Autoconf 2.62,
  with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"

Copyright (C) 2008 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

# Set your package name and version numbers here.
#
# This initializes the environment with PACKAGE_NAME and PACKAGE_VERSION
# set as provided.  These will also be added as -D defs in your Makefile
# so you can encode the package version directly into the source files.
#-----------------------------------------------------------------------

AC_INIT([sqlite], [3.6.3])
AC_INIT([sqlite], [3.6.5])

#--------------------------------------------------------------------
# Call TEA_INIT as the first TEA_ macro to set up initial vars.
# This will define a ${TEA_PLATFORM} variable == "unix" or "windows"
# as well as PKG_LIB_FILE and PKG_STUB_LIB_FILE.
#--------------------------------------------------------------------

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.6.3.  By combining all the individual C code files into this 
** version 3.6.5.  By combining all the individual C code files into this 
** single large file, the entire code can be compiled as a one translation
** unit.  This allows many compilers to do optimizations that would not be
** possible if the files were compiled separately.  Performance improvements
** of 5% are more are commonly seen when SQLite is compiled as a single
** translation unit.
**
** This file is all you need to compile SQLite.  To use SQLite in other
** programs, you need this file and the "sqlite3.h" header file that defines
** the programming interface to the SQLite library.  (If you do not have 
** the "sqlite3.h" header file at hand, you will find a copy in the first
** 6364 lines past this header comment.)  Additional code files may be
** 6569 lines past this header comment.)  Additional code files may be
** needed if you want a wrapper to interface SQLite with your choice of
** programming language.  The code for the "sqlite3" command-line shell
** is also in a separate file.  This file contains only code for the core
** SQLite library.
**
** This amalgamation was generated on 2008-09-21 23:14:08 UTC.
** This amalgamation was generated on 2008-11-12 15:36:54 UTC.
*/
#define SQLITE_CORE 1
#define SQLITE_AMALGAMATION 1
#ifndef SQLITE_PRIVATE
# define SQLITE_PRIVATE static
#endif
#ifndef SQLITE_API

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.772 2008/09/12 16:03:48 drh Exp $
** @(#) $Id: sqliteInt.h,v 1.790 2008/11/11 18:29:00 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build

** 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 1.398 2008/09/10 13:09:24 drh Exp $
** @(#) $Id: sqlite.h.in,v 1.412 2008/11/10 23:54:06 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++.

** Add the ability to override 'extern'
*/
#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif

/*
** These no-op macros are used in front of interfaces to mark those
** Add the ability to mark interfaces as deprecated.
*/
** interfaces as either deprecated or experimental.  New applications
** should not use deprecated intrfaces - they are support for backwards
** compatibility only.  Application writers should be aware that
** experimental interfaces are subject to change in point releases.
**
#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
  /* GCC added the deprecated attribute in version 3.1 */
  #define SQLITE_DEPRECATED __attribute__ ((deprecated))
#elif defined(_MSC_VER) && (_MSC_VER>1200) 
  #define SQLITE_DEPRECATED __declspec(deprecated)
#else
  #define SQLITE_DEPRECATED
** These macros used to resolve to various kinds of compiler magic that
** would generate warning messages when they were used.  But that
** compiler magic ended up generating such a flurry of bug reports
#endif

/*
** that we have taken it all out and gone back to using simple
** noop macros.
** Add the ability to mark interfaces as experimental.
*/
#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
  /* I can confirm that it does not work on version 4.1.0... */
  /* First appears in GCC docs for version 4.3.0 */
  #define SQLITE_EXPERIMENTAL __attribute__ ((warning ("is experimental")))
#define SQLITE_DEPRECATED
#elif defined(_MSC_VER) && (_MSC_VER>1200) 
  #define SQLITE_EXPERIMENTAL __declspec(deprecated("was declared experimental"))
#else
  #define SQLITE_EXPERIMENTAL
#define SQLITE_EXPERIMENTAL
#endif

/*
** Ensure these symbols were not defined by some previous header file.
*/
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif

**          evaluate to a string literal that is the SQLite version
**          with which the header file is associated.
**
** {H10014} The SQLITE_VERSION_NUMBER #define shall resolve to an integer
**          with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z
**          are the major version, minor version, and release number.
*/
#define SQLITE_VERSION         "3.6.3"
#define SQLITE_VERSION_NUMBER  3006003
#define SQLITE_VERSION         "3.6.5"
#define SQLITE_VERSION_NUMBER  3006005

/*
** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100>
** KEYWORDS: sqlite3_version
**
** These features provide the same information as the [SQLITE_VERSION]
** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated

** only the default compile-time setting, not any run-time changes
** to that setting.
**
** See the [threading mode] documentation for additional information.
**
** INVARIANTS:
**
** {H10101} The [sqlite3_threadsafe()] function shall return nonzero if
**          and only if
** {H10101} The [sqlite3_threadsafe()] function shall return zero if
**          and only if SQLite was compiled with mutexing code omitted.
**          SQLite was compiled with the its mutexes enabled by default.
**
** {H10102} The value returned by the [sqlite3_threadsafe()] function
**          shall not change when mutex setting are modified at
**          runtime using the [sqlite3_config()] interface and 
**          shall remain the same across calls to [sqlite3_config()].
**          especially the [SQLITE_CONFIG_SINGLETHREAD],
**          [SQLITE_CONFIG_MULTITHREAD], [SQLITE_CONFIG_SERIALIZED],
**          and [SQLITE_CONFIG_MUTEX] verbs.
*/
SQLITE_API int sqlite3_threadsafe(void);

/*
** CAPI3REF: Database Connection Handle {H12000} <S40200>
** KEYWORDS: {database connection} {database connections}
**

**          C.
**
** {H12014} A call to [sqlite3_close(C)] on a [database connection] C that
**          has one or more open [prepared statements] shall fail with
**          an [SQLITE_BUSY] error code.
**
** {H12015} A call to [sqlite3_close(C)] where C is a NULL pointer shall
**          return SQLITE_OK.
**          be a harmless no-op returning SQLITE_OK.
**
** {H12019} When [sqlite3_close(C)] is invoked on a [database connection] C
**          that has a pending transaction, the transaction shall be
**          rolled back.
**
** ASSUMPTIONS:
**

**          in *E an appropriate error message written into memory obtained
**          from [sqlite3_malloc()].
**
** {H12134} The [sqlite3_exec(D,S,C,A,E)] routine shall set the value of
**          *E to NULL if E is not NULL and there are no errors.
**
** {H12137} The [sqlite3_exec(D,S,C,A,E)] function shall set the [error code]
**          and message accessible via [sqlite3_errcode()],
**          and message accessible via [sqlite3_errcode()], 
**          [sqlite3_extended_errcode()],
**          [sqlite3_errmsg()], and [sqlite3_errmsg16()].
**
** {H12138} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL or an
**          empty string or contains nothing other than whitespace, comments,
**          and/or semicolons, then results of [sqlite3_errcode()],
**          [sqlite3_extended_errcode()],
**          [sqlite3_errmsg()], and [sqlite3_errmsg16()]
**          shall reset to indicate no errors.
**
** ASSUMPTIONS:
**
** {A12141} The first parameter to [sqlite3_exec()] must be an valid and open
**          [database connection].

** [sqlite3_io_methods] object it uses a combination of
** these integer values as the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
** information need not be flushed. The SQLITE_SYNC_NORMAL flag means
** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means
** to use Mac OS-X style fullsync instead of fsync().
** to use Mac OS X style fullsync instead of fsync().
*/
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010

/*
** CAPI3REF: OS Interface Open File Handle {H11110} <S20110>

** [sqlite3_file] object (or, more commonly, a subclass of the
** [sqlite3_file] object) with a pointer to an instance of this object.
** This object defines the methods used to perform various operations
** against the open file represented by the [sqlite3_file] object.
**
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
** The second choice is a Mac OS-X style fullsync.  The [SQLITE_SYNC_DATAONLY]
** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
** flag may be ORed in to indicate that only the data of the file
** and not its inode needs to be synced.
**
** The integer values to xLock() and xUnlock() are one of
** <ul>
** <li> [SQLITE_LOCK_NONE],
** <li> [SQLITE_LOCK_SHARED],

** are aligned to an address which is an integer multiple of
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
** that when data is appended to a file, the data is appended
** first then the size of the file is extended, never the other
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
** information is written to disk in the same order as calls
** to xWrite().
**
** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
** in the unread portions of the buffer with zeros.  A VFS that
** fails to zero-fill short reads might seem to work.  However,
** failure to zero-fill short reads will eventually lead to
** database corruption.
*/
typedef struct sqlite3_io_methods sqlite3_io_methods;
struct sqlite3_io_methods {
  int iVersion;
  int (*xClose)(sqlite3_file*);
  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);

** of sqlite3_initialize() does any initialization.  All other calls
** are harmless no-ops.
**
** Among other things, sqlite3_initialize() shall invoke
** sqlite3_os_init().  Similarly, sqlite3_shutdown()
** shall invoke sqlite3_os_end().
**
** The sqlite3_initialize() routine returns SQLITE_OK on success.
** The sqlite3_initialize() routine returns [SQLITE_OK] on success.
** If for some reason, sqlite3_initialize() is unable to initialize
** the library (perhaps it is unable to allocate a needed resource such
** as a mutex) it returns an [error code] other than SQLITE_OK.
** as a mutex) it returns an [error code] other than [SQLITE_OK].
**
** The sqlite3_initialize() routine is called internally by many other
** SQLite interfaces so that an application usually does not need to
** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
** calls sqlite3_initialize() so the SQLite library will be automatically
** initialized when [sqlite3_open()] is called if it has not be initialized
** already.  However, if SQLite is compiled with the SQLITE_OMIT_AUTOINIT
** already.  However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
** compile-time option, then the automatic calls to sqlite3_initialize()
** are omitted and the application must call sqlite3_initialize() directly
** prior to using any other SQLite interface.  For maximum portability,
** it is recommended that applications always invoke sqlite3_initialize()
** directly prior to using any other SQLite interface.  Future releases
** of SQLite may require this.  In other words, the behavior exhibited
** when SQLite is compiled with SQLITE_OMIT_AUTOINIT might become the
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
** default behavior in some future release of SQLite.
**
** The sqlite3_os_init() routine does operating-system specific
** initialization of the SQLite library.  The sqlite3_os_end()
** routine undoes the effect of sqlite3_os_init().  Typical tasks
** performed by these routines include allocation or deallocation
** of static resources, initialization of global variables,
** setting up a default [sqlite3_vfs] module, or setting up
** a default configuration using [sqlite3_config()].
**
** The application should never invoke either sqlite3_os_init()
** or sqlite3_os_end() directly.  The application should only invoke
** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
** interface is called automatically by sqlite3_initialize() and
** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
** implementations for sqlite3_os_init() and sqlite3_os_end()
** are built into SQLite when it is compiled for unix, windows, or os/2.
** When built for other platforms (using the SQLITE_OS_OTHER=1 compile-time
** When built for other platforms (using the [SQLITE_OS_OTHER=1] compile-time
** option) the application must supply a suitable implementation for
** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
** implementation of sqlite3_os_init() or sqlite3_os_end()
** must return SQLITE_OK on success and some other [error code] upon
** must return [SQLITE_OK] on success and some other [error code] upon
** failure.
*/
SQLITE_API int sqlite3_initialize(void);
SQLITE_API int sqlite3_shutdown(void);
SQLITE_API int sqlite3_os_init(void);
SQLITE_API int sqlite3_os_end(void);

/*
** CAPI3REF: Configuring The SQLite Library {H10145} <S20000><S30200>
** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200>
** EXPERIMENTAL
**
** The sqlite3_config() interface is used to make global configuration
** changes to SQLite in order to tune SQLite to the specific needs of
** the application.  The default configuration is recommended for most
** applications and so this routine is usually not necessary.  It is
** provided to support rare applications with unusual needs.

**
** The first argument to sqlite3_config() is an integer
** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines
** what property of SQLite is to be configured.  Subsequent arguments
** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option]
** in the first argument.
**
** When a configuration option is set, sqlite3_config() returns SQLITE_OK.
** When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
** If the option is unknown or SQLite is unable to set the option
** then this routine returns a non-zero [error code].
**
** INVARIANTS:
**
** {H14103} A successful invocation of [sqlite3_config()] shall return
**          [SQLITE_OK].
**
** {H14106} The [sqlite3_config()] interface shall return [SQLITE_MISUSE]
**          if it is invoked in between calls to [sqlite3_initialize()] and
**          [sqlite3_shutdown()].
**
** {H14120} A successful call to [sqlite3_config]([SQLITE_CONFIG_SINGLETHREAD])
**          shall set the default [threading mode] to Single-thread.
**
** {H14123} A successful call to [sqlite3_config]([SQLITE_CONFIG_MULTITHREAD])
**          shall set the default [threading mode] to Multi-thread.
**
** {H14126} A successful call to [sqlite3_config]([SQLITE_CONFIG_SERIALIZED])
**          shall set the default [threading mode] to Serialized.
**
** {H14129} A successful call to [sqlite3_config]([SQLITE_CONFIG_MUTEX],X)
**          where X is a pointer to an initialized [sqlite3_mutex_methods]
**          object shall cause all subsequent mutex operations performed
**          by SQLite to use the mutex methods that were present in X
**          during the call to [sqlite3_config()].
**
** {H14132} A successful call to [sqlite3_config]([SQLITE_CONFIG_GETMUTEX],X)
**          where X is a pointer to an [sqlite3_mutex_methods] object 
**          shall overwrite the content of [sqlite3_mutex_methods] object
**          with the mutex methods currently in use by SQLite.
**
** {H14135} A successful call to [sqlite3_config]([SQLITE_CONFIG_MALLOC],M)
**          where M is a pointer to an initialized [sqlite3_mem_methods]
**          object shall cause all subsequent memory allocation operations
**          performed by SQLite to use the methods that were present in 
**          M during the call to [sqlite3_config()].
**
** {H14138} A successful call to [sqlite3_config]([SQLITE_CONFIG_GETMALLOC],M)
**          where M is a pointer to an [sqlite3_mem_methods] object shall
**          overwrite the content of [sqlite3_mem_methods] object with 
**          the memory allocation methods currently in use by
**          SQLite.
**
** {H14141} A successful call to [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],1)
**          shall enable the memory allocation status collection logic.
**
** {H14144} A successful call to [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],0)
**          shall disable the memory allocation status collection logic.
**
** {H14147} The memory allocation status collection logic shall be
**          enabled by default.
**
** {H14150} A successful call to [sqlite3_config]([SQLITE_CONFIG_SCRATCH],S,Z,N)
**          where Z and N are non-negative integers and 
**          S is a pointer to an aligned memory buffer not less than
**          Z*N bytes in size shall cause S to be used by the
**          [scratch memory allocator] for as many as N simulataneous
**          allocations each of size Z.
**
** {H14153} A successful call to [sqlite3_config]([SQLITE_CONFIG_SCRATCH],S,Z,N)
**          where S is a NULL pointer shall disable the
**          [scratch memory allocator].
**
** {H14156} A successful call to
**          [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],S,Z,N)
**          where Z and N are non-negative integers and 
**          S is a pointer to an aligned memory buffer not less than
**          Z*N bytes in size shall cause S to be used by the
**          [pagecache memory allocator] for as many as N simulataneous
**          allocations each of size Z.
**
** {H14159} A successful call to
**          [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],S,Z,N)
**          where S is a NULL pointer shall disable the
**          [pagecache memory allocator].
**
** {H14162} A successful call to [sqlite3_config]([SQLITE_CONFIG_HEAP],H,Z,N)
**          where Z and N are non-negative integers and 
**          H is a pointer to an aligned memory buffer not less than
**          Z bytes in size shall enable the [memsys5] memory allocator
**          and cause it to use buffer S as its memory source and to use
**          a minimum allocation size of N.
**
** {H14165} A successful call to [sqlite3_config]([SQLITE_CONFIG_HEAP],H,Z,N)
**          where H is a NULL pointer shall disable the
**          [memsys5] memory allocator.
**
** {H14168} A successful call to [sqlite3_config]([SQLITE_CONFIG_LOOKASIDE],Z,N)
**          shall cause the default [lookaside memory allocator] configuration
**          for new [database connections] to be N slots of Z bytes each.
*/
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_config(int, ...);

/*
** CAPI3REF: Configure database connections  {H10180} <S20000>
** CAPI3REF: Configure database connections  {H14200} <S20000>
** EXPERIMENTAL
**
** The sqlite3_db_config() interface is used to make configuration
** changes to a [database connection].  The interface is similar to
** [sqlite3_config()] except that the changes apply to a single
** [database connection] (specified in the first argument).  The
** sqlite3_db_config() interface can only be used immediately after
** the database connection is created using [sqlite3_open()],
** [sqlite3_open16()], or [sqlite3_open_v2()].  
**
** The second argument to sqlite3_db_config(D,V,...)  is the
** configuration verb - an integer code that indicates what
** aspect of the [database connection] is being configured.
** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].
** New verbs are likely to be added in future releases of SQLite.
** Additional arguments depend on the verb.
**
** INVARIANTS:
**
** {H14203} A call to [sqlite3_db_config(D,V,...)] shall return [SQLITE_OK]
**          if and only if the call is successful.
**
** {H14206} If one or more slots of the [lookaside memory allocator] for
**          [database connection] D are in use, then a call to
**          [sqlite3_db_config](D,[SQLITE_DBCONFIG_LOOKASIDE],...) shall
**          fail with an [SQLITE_BUSY] return code.
**
** {H14209} A successful call to 
**          [sqlite3_db_config](D,[SQLITE_DBCONFIG_LOOKASIDE],B,Z,N) where
**          D is an open [database connection] and Z and N are positive
**          integers and B is an aligned buffer at least Z*N bytes in size
**          shall cause the [lookaside memory allocator] for D to use buffer B 
**          with N slots of Z bytes each.
**
** {H14212} A successful call to 
**          [sqlite3_db_config](D,[SQLITE_DBCONFIG_LOOKASIDE],B,Z,N) where
**          D is an open [database connection] and Z and N are positive
**          integers and B is NULL pointer shall cause the
**          [lookaside memory allocator] for D to a obtain Z*N byte buffer
**          from the primary memory allocator and use that buffer
**          with N lookaside slots of Z bytes each.
**
** {H14215} A successful call to 
**          [sqlite3_db_config](D,[SQLITE_DBCONFIG_LOOKASIDE],B,Z,N) where
**          D is an open [database connection] and Z and N are zero shall
**          disable the [lookaside memory allocator] for D.
**
**
*/
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...);

/*
** CAPI3REF: Memory Allocation Routines {H10155} <S20120>
** EXPERIMENTAL
**

#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_CHUNKALLOC   12  /* int threshold */
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */

/*
** CAPI3REF: Configuration Options {H10170} <S20000>
** EXPERIMENTAL
**
** These constants are the available integer configuration options that

** 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
** successful [INSERT] into the database from the [database connection]
** in the first argument.  If no successful [INSERT]s
** have ever occurred on that database connection, zero is returned.
**
** If an INSERT occurs within a trigger, then the rowid of the inserted
** 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
** 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
** For the purposes of this routine, an [INSERT] is considered to
** be successful even if it is subsequently rolled back.
**
** INVARIANTS:
**
** {H12221} The [sqlite3_last_insert_rowid()] function returns the rowid
**          of the most recent successful INSERT performed on the same
** {H12221} The [sqlite3_last_insert_rowid()] function shall return 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.
**          trigger context, or zero if there have been no qualifying
**          [INSERT] statements.
**
** {H12223} The [sqlite3_last_insert_rowid()] function returns the
** {H12223} The [sqlite3_last_insert_rowid()] function shall return the
**          same value when called from the same trigger context
**          immediately before and after a ROLLBACK.
**          immediately before and after a [ROLLBACK].
**
** ASSUMPTIONS:
**
** {A12232} If a separate thread performs a new INSERT on the same
** {A12232} If a separate thread performs a new [INSERT] on the same
**          database connection while the [sqlite3_last_insert_rowid()]
**          function is running and thus changes the last insert rowid,
**          then the value returned by [sqlite3_last_insert_rowid()] is
**          unpredictable and might not equal either the old or the new
**          last insert rowid.
*/
SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600>
**
** 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
** 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

** 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
** by dropping and recreating the table.  Doing so 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.
** "DELETE FROM table WHERE 1" instead.  Or recompile using the
** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the
** optimization on all queries.
**
** INVARIANTS:
**
** {H12241} 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

** 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.
** "DELETE FROM table WHERE 1" instead.   Or recompile using the
** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the
** optimization on all queries.
**
** See also the [sqlite3_changes()] interface.
**
** INVARIANTS:
**
** {H12261} The [sqlite3_total_changes()] returns the total number
**          of row changes caused by INSERT, UPDATE, and/or DELETE

** that it might be reused.  The sqlite3_free() routine is
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
** to sqlite3_free() is harmless.  After being freed, memory
** should neither be read nor written.  Even reading previously freed
** memory might result in a segmentation fault or other severe error.
** Memory corruption, a segmentation fault, or other severe error
** might result if sqlite3_free() is called with a non-NULL pointer that
** was not obtained from sqlite3_malloc() or sqlite3_free().
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
**
** The sqlite3_realloc() interface attempts to resize a
** prior memory allocation to be at least N bytes, where N is the
** 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().

#define SQLITE_ATTACH               24   /* Filename        NULL            */
#define SQLITE_DETACH               25   /* Database Name   NULL            */
#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
#define SQLITE_REINDEX              27   /* Index Name      NULL            */
#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* Function Name   NULL            */
#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
#define SQLITE_COPY                  0   /* No longer used */

/*
** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400>
** EXPERIMENTAL
**
** These routines register callback functions that can be used for

/*
** CAPI3REF: Error Codes And Messages {H12800} <S60200>
**
** The sqlite3_errcode() interface returns the numeric [result code] or
** [extended result code] for the most recent failed sqlite3_* API call
** associated with a [database connection]. If a prior API call failed
** but the most recent API call succeeded, the return value from
** sqlite3_errcode() is undefined.
** sqlite3_errcode() is undefined.  The sqlite3_extended_errcode()
** interface is the same except that it always returns the 
** [extended result code] even when extended result codes are
** disabled.
**
** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF-8 or UTF-16 respectively.
** Memory to hold the error message string is managed internally.
** The application does not need to worry about freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.
**
** When the serialized [threading mode] is in use, it might be the
** case that a second error occurs on a separate thread in between
** the time of the first error and the call to these interfaces.
** When that happens, the second error will be reported since these
** interfaces always report the most recent result.  To avoid
** this, each thread can obtain exclusive use of the [database connection] D
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
** all calls to the interfaces listed here are completed.
**
** If an interface fails with SQLITE_MISUSE, that means the interface
** was invoked incorrectly by the application.  In that case, the
** error code and message may or may not be set.
**
** INVARIANTS:
**
** {H12801} The [sqlite3_errcode(D)] interface returns the numeric
**          [result code] or [extended result code] for the most recently
**          failed interface call associated with the [database connection] D.
**
** {H12802} The [sqlite3_extended_errcode(D)] interface returns the numeric
**          [extended result code] for the most recently
**          failed interface call associated with the [database connection] D.
**
** {H12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]
**          interfaces return English-language text that describes
**          the error in the mostly recently failed interface call,
**          encoded as either UTF-8 or UTF-16 respectively.
**
** {H12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]
**          are valid until the next SQLite interface call.
**
** {H12808} Calls to API routines that do not return an error code
**          (example: [sqlite3_data_count()]) do not
**          change the error code or message returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**          [sqlite3_errcode()], [sqlite3_extended_errcode()],
**          [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**
** {H12809} Interfaces that are not associated with a specific
**          [database connection] (examples:
**          [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()]
**          do not change the values returned by
**          [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
**          [sqlite3_errcode()], [sqlite3_extended_errcode()],
**          [sqlite3_errmsg()], or [sqlite3_errmsg16()].
*/
SQLITE_API int sqlite3_errcode(sqlite3 *db);
SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
SQLITE_API const char *sqlite3_errmsg(sqlite3*);
SQLITE_API const void *sqlite3_errmsg16(sqlite3*);

/*
** CAPI3REF: SQL Statement Object {H13000} <H13010>
** KEYWORDS: {prepared statement} {prepared statements}
**

  const void *zSql,       /* SQL statement, UTF-16 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
);

/*
** CAPIREF: Retrieving Statement SQL {H13100} <H13000>
** CAPI3REF: Retrieving Statement SQL {H13100} <H13000>
**
** This interface can be used to retrieve a saved copy of the original
** SQL text used to create a [prepared statement] if that statement was
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
**
** INVARIANTS:
**

** CAPI3REF: Deprecated Functions
** DEPRECATED
**
** These functions are [deprecated].  In order to maintain
** backwards compatibility with older code, these functions continue 
** to be supported.  However, new applications should avoid
** the use of these functions.  To help encourage people to avoid
** using these functions, we are not going to tell you want they do.
** using these functions, we are not going to tell you what they do.
*/
#ifndef SQLITE_OMIT_DEPRECATED
SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
#endif

/*
** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200>
**
** The C-language implementation of SQL functions and aggregates uses
** this set of interface routines to access the parameter values on
** the function or aggregate.

**          parameter is non-zero.
**
** {H17819} The [sqlite3_blob_open()] interface shall return [SQLITE_OK] on
**          success and an appropriate [error code] on failure.
**
** {H17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_extended_errcode()], 
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
**          information appropriate for that error.
**
** {H17824} If any column in the row that a [sqlite3_blob] has open is
**          changed by a separate [UPDATE] or [DELETE] statement or by
**          an [ON CONFLICT] side effect, then the [sqlite3_blob] shall
**          be marked as invalid.

**
** {H17865} If the requested read could not be completed,
**          the [sqlite3_blob_read(P,Z,N,X)] interface shall return an
**          appropriate [error code] or [extended error code].
**
** {H17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_extended_errcode()],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
**          information appropriate for that error, where D is the
**          [database connection] that was used to open the [BLOB handle] P.
*/
SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*

**
** {H17885} If the requested write could not be completed,
**          the [sqlite3_blob_write(P,Z,N,X)] interface shall return an
**          appropriate [error code] or [extended error code].
**
** {H17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]
**          then subsequent calls to [sqlite3_errcode(D)],
**          [sqlite3_extended_errcode()],
**          [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
**          information appropriate for that error.
*/
SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF: Virtual File System Objects {H11200} <S20100>

#define SQLITE_MUTEX_STATIC_MASTER    2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* sqlite3_release_memory() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */

/*
** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000>
**
** This interface returns a pointer the [sqlite3_mutex] object that 
** serializes access to the [database connection] given in the argument
** when the [threading mode] is Serialized.
** If the [threading mode] is Single-thread or Multi-thread then this
** routine returns a NULL pointer.
*/
SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);

/*
** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800>
**
** {H11301} The [sqlite3_file_control()] interface makes a direct call to the
** xFileControl method for the [sqlite3_io_methods] object associated
** with a particular database identified by the second argument. {H11302} The
** name of the database is the name assigned to the database by the

** and it is possible that another thread might change the parameter
** in between the times when *pCurrent and *pHighwater are written.
**
** See also: [sqlite3_db_status()]
*/
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);

/*
** CAPI3REF: Database Connection Status {H17201} <S60200>
** EXPERIMENTAL
**
** This interface is used to retrieve runtime status information 
** about a single [database connection].  The first argument is the
** database connection object to be interrogated.  The second argument
** is the parameter to interrogate.  Currently, the only allowed value
** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].
** Additional options will likely appear in future releases of SQLite.
**
** The current value of the request parameter is written into *pCur
** and the highest instantaneous value is written into *pHiwtr.  If
** the resetFlg is true, then the highest instantaneous value is
** reset back down to the current value.
**
** See also: [sqlite3_status()].
*/
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);


SQLITE_API int sqlite3_wsd_init(int N, int J);
SQLITE_API void *sqlite3_wsd_find(void *K, int L);

/*
** CAPI3REF: Status Parameters {H17250} <H17200>
** EXPERIMENTAL
**
** These integer constants designate various run-time status parameters
** that can be returned by [sqlite3_status()].

#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
#define SQLITE_STATUS_MALLOC_SIZE          5
#define SQLITE_STATUS_PARSER_STACK         6
#define SQLITE_STATUS_PAGECACHE_SIZE       7
#define SQLITE_STATUS_SCRATCH_SIZE         8

/*
** CAPI3REF: Database Connection Status {H17500} <S60200>
** EXPERIMENTAL
**
** This interface is used to retrieve runtime status information 
** about a single [database connection].  The first argument is the
** database connection object to be interrogated.  The second argument
** is the parameter to interrogate.  Currently, the only allowed value
** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].
** Additional options will likely appear in future releases of SQLite.
**
** The current value of the requested parameter is written into *pCur
** and the highest instantaneous value is written into *pHiwtr.  If
** the resetFlg is true, then the highest instantaneous value is
** reset back down to the current value.
**
** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
*/
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);

/*
** CAPI3REF: Status Parameters for database connections {H17275} <H17200>
** CAPI3REF: Status Parameters for database connections {H17520} <H17500>
** EXPERIMENTAL
**
** Status verbs for [sqlite3_db_status()].
**
** <dl>
** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
** <dd>This parameter returns the number of lookaside memory slots currently
** checked out.</dd>
** </dl>
*/
#define SQLITE_DBSTATUS_LOOKASIDE_USED     0


/*
** CAPI3REF: Prepared Statement Status {H17550} <S60200>
** EXPERIMENTAL
**
** Each prepared statement maintains various
** [SQLITE_STMTSTATUS_SORT | counters] that measure the number
** of times it has performed specific operations.  These counters can
** be used to monitor the performance characteristics of the prepared
** statements.  For example, if the number of table steps greatly exceeds
** the number of table searches or result rows, that would tend to indicate
** that the prepared statement is using a full table scan rather than
** an index.  
**
** This interface is used to retrieve and reset counter values from
** a [prepared statement].  The first argument is the prepared statement
** object to be interrogated.  The second argument
** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter]
** to be interrogated. 
** The current value of the requested counter is returned.
** If the resetFlg is true, then the counter is reset to zero after this
** interface call returns.
**
** See also: [sqlite3_status()] and [sqlite3_db_status()].
*/
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);

/*
** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550>
** EXPERIMENTAL
**
** These preprocessor macros define integer codes that name counter
** values associated with the [sqlite3_stmt_status()] interface.
** The meanings of the various counters are as follows:
**
** <dl>
** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
** <dd>This is the number of times that SQLite has stepped forward in
** a table as part of a full table scan.  Large numbers for this counter
** may indicate opportunities for performance improvement through 
** careful use of indices.</dd>
**
** <dt>SQLITE_STMTSTATUS_SORT</dt>
** <dd>This is the number of sort operations that have occurred.
** A non-zero value in this counter may indicate an opportunity to
** improvement performance through careful use of indices.</dd>
**
** </dl>
*/
#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
#define SQLITE_STMTSTATUS_SORT              2

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the header file for the generic hash-table implemenation
** used in SQLite.
**
** $Id: hash.h,v 1.11 2007/09/04 14:31:47 danielk1977 Exp $
** $Id: hash.h,v 1.12 2008/10/10 17:41:29 drh Exp $
*/
#ifndef _SQLITE_HASH_H_
#define _SQLITE_HASH_H_

/* Forward declarations of structures. */
typedef struct Hash Hash;
typedef struct HashElem HashElem;

/* A complete hash table is an instance of the following structure.
** The internals of this structure are intended to be opaque -- client
** code should not attempt to access or modify the fields of this structure
** directly.  Change this structure only by using the routines below.
** However, many of the "procedures" and "functions" for modifying and
** accessing this structure are really macros, so we can't really make
** this structure opaque.
*/
struct Hash {
  char keyClass;          /* SQLITE_HASH_INT, _POINTER, _STRING, _BINARY */
  char copyKey;           /* True if copy of key made on insert */
  unsigned int copyKey: 1;  /* True if copy of key made on insert */
  int count;              /* Number of entries in this table */
  int htsize;             /* Number of buckets in the hash table */
  HashElem *first;        /* The first element of the array */
  struct _ht {            /* the hash table */
    int count;               /* Number of entries with this hash */
    HashElem *chain;         /* Pointer to first entry with this hash */
  unsigned int htsize : 31; /* Number of buckets in the hash table */
  unsigned int count;       /* Number of entries in this table */
  HashElem *first;          /* The first element of the array */
  struct _ht {              /* the hash table */
    int count;                 /* Number of entries with this hash */
    HashElem *chain;           /* Pointer to first entry with this hash */
  } *ht;
};

/* Each element in the hash table is an instance of the following 
** structure.  All elements are stored on a single doubly-linked list.
**
** Again, this structure is intended to be opaque, but it can't really
** be opaque because it is used by macros.
*/
struct HashElem {
  HashElem *next, *prev;   /* Next and previous elements in the table */
  void *data;              /* Data associated with this element */
  void *pKey; int nKey;    /* Key associated with this element */
};

/*
** There are 4 different modes of operation for a hash table:
**
**   SQLITE_HASH_INT         nKey is used as the key and pKey is ignored.
**
**   SQLITE_HASH_POINTER     pKey is used as the key and nKey is ignored.
**
**   SQLITE_HASH_STRING      pKey points to a string that is nKey bytes long
**                           (including the null-terminator, if any).  Case
**                           is ignored in comparisons.
**
**   SQLITE_HASH_BINARY      pKey points to binary data nKey bytes long. 
**                           memcmp() is used to compare keys.
**
** A copy of the key is made for SQLITE_HASH_STRING and SQLITE_HASH_BINARY
** if the copyKey parameter to HashInit is 1.  
*/
/* #define SQLITE_HASH_INT       1 // NOT USED */
/* #define SQLITE_HASH_POINTER   2 // NOT USED */
#define SQLITE_HASH_STRING    3
#define SQLITE_HASH_BINARY    4

/*
** Access routines.  To delete, insert a NULL pointer.
*/
SQLITE_PRIVATE void sqlite3HashInit(Hash*, int keytype, int copyKey);
SQLITE_PRIVATE void sqlite3HashInit(Hash*, int copyKey);
SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData);
SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const void *pKey, int nKey);
SQLITE_PRIVATE HashElem *sqlite3HashFindElem(const Hash*, const void *pKey, int nKey);
SQLITE_PRIVATE void sqlite3HashClear(Hash*);

/*
** Macros for looping over all elements of a hash table.  The idiom is

#define TK_EXCEPT                         108
#define TK_INTERSECT                      109
#define TK_SELECT                         110
#define TK_DISTINCT                       111
#define TK_DOT                            112
#define TK_FROM                           113
#define TK_JOIN                           114
#define TK_INDEXED                        115
#define TK_BY                             116
#define TK_USING                          115
#define TK_ORDER                          116
#define TK_USING                          117
#define TK_ORDER                          118
#define TK_BY                             117
#define TK_GROUP                          118
#define TK_HAVING                         119
#define TK_LIMIT                          120
#define TK_WHERE                          121
#define TK_INTO                           122
#define TK_VALUES                         123
#define TK_INTEGER                        124
#define TK_FLOAT                          125
#define TK_BLOB                           126
#define TK_REGISTER                       127
#define TK_VARIABLE                       128
#define TK_CASE                           129
#define TK_WHEN                           130
#define TK_THEN                           131
#define TK_ELSE                           132
#define TK_INDEX                          133
#define TK_ALTER                          134
#define TK_TO                             135
#define TK_ADD                            136
#define TK_COLUMNKW                       137
#define TK_TO_TEXT                        138
#define TK_TO_BLOB                        139
#define TK_TO_NUMERIC                     140
#define TK_TO_INT                         141
#define TK_TO_REAL                        142
#define TK_END_OF_FILE                    143
#define TK_ILLEGAL                        144
#define TK_SPACE                          145
#define TK_UNCLOSED_STRING                146
#define TK_FUNCTION                       147
#define TK_COLUMN                         148
#define TK_AGG_FUNCTION                   149
#define TK_AGG_COLUMN                     150
#define TK_CONST_FUNC                     151
#define TK_GROUP                          119
#define TK_HAVING                         120
#define TK_LIMIT                          121
#define TK_WHERE                          122
#define TK_INTO                           123
#define TK_VALUES                         124
#define TK_INTEGER                        125
#define TK_FLOAT                          126
#define TK_BLOB                           127
#define TK_REGISTER                       128
#define TK_VARIABLE                       129
#define TK_CASE                           130
#define TK_WHEN                           131
#define TK_THEN                           132
#define TK_ELSE                           133
#define TK_INDEX                          134
#define TK_ALTER                          135
#define TK_TO                             136
#define TK_ADD                            137
#define TK_COLUMNKW                       138
#define TK_TO_TEXT                        139
#define TK_TO_BLOB                        140
#define TK_TO_NUMERIC                     141
#define TK_TO_INT                         142
#define TK_TO_REAL                        143
#define TK_END_OF_FILE                    144
#define TK_ILLEGAL                        145
#define TK_SPACE                          146
#define TK_UNCLOSED_STRING                147
#define TK_FUNCTION                       148
#define TK_COLUMN                         149
#define TK_AGG_FUNCTION                   150
#define TK_AGG_COLUMN                     151
#define TK_CONST_FUNC                     152

/************** End of parse.h ***********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

** evaluated at runtime.
*/
#ifdef SQLITE_AMALGAMATION
SQLITE_PRIVATE const int sqlite3one;
#else
SQLITE_PRIVATE const int sqlite3one;
#endif
#if defined(i386) || defined(__i386__) || defined(_M_IX86)
#if defined(i386) || defined(__i386__) || defined(_M_IX86)\
                             || defined(__x86_64) || defined(__x86_64__)
# define SQLITE_BIGENDIAN    0
# define SQLITE_LITTLEENDIAN 1
# define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
#else
# define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
# define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)

** the heap.  When WSD is unsupported, the variable declarations scattered
** throughout the SQLite code must become constants instead.  The SQLITE_WSD
** macro is used for this purpose.  And instead of referencing the variable
** directly, we use its constant as a key to lookup the run-time allocated
** buffer that holds real variable.  The constant is also the initializer
** for the run-time allocated buffer.
**
** In the usually case where WSD is supported, the SQLITE_WSD and GLOBAL
** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
** macros become no-ops and have zero performance impact.
*/
#ifdef SQLITE_OMIT_WSD
  #define SQLITE_WSD const
  #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
  #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
SQLITE_API   int sqlite3_wsd_init(int N, int J);
SQLITE_API   void *sqlite3_wsd_find(void *K, int L);
#else
  #define SQLITE_WSD 
  #define GLOBAL(t,v) v
  #define sqlite3GlobalConfig sqlite3Config
#endif

/*

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.103 2008/08/13 19:11:48 drh Exp $
** @(#) $Id: btree.h,v 1.105 2008/10/27 13:59:34 danielk1977 Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

** of the following flags:
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_ZERODATA   2    /* Table has keys only - no data */
#define BTREE_LEAFDATA   4    /* Data stored in leaves only.  Implies INTKEY */

SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree*, int, int*);
SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree*, int);
SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree*, int, int*);
SQLITE_PRIVATE int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
SQLITE_PRIVATE void sqlite3BtreeTripAllCursors(Btree*, int);

SQLITE_PRIVATE int sqlite3BtreeCursor(
  Btree*,                              /* BTree containing table to open */
  int iTable,                          /* Index of root page */

SQLITE_PRIVATE int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*);

SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
SQLITE_PRIVATE void sqlite3BtreeCacheOverflow(BtCursor *);
SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *);

#ifdef SQLITE_TEST
SQLITE_PRIVATE int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
SQLITE_PRIVATE void sqlite3BtreeCursorList(Btree*);
#endif

/*

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.138 2008/08/20 22:06:48 drh Exp $
** $Id: vdbe.h,v 1.139 2008/10/31 10:53:23 danielk1977 Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
** in the source file sqliteVdbe.c are allowed to see the insides

/************** Begin file opcodes.h *****************************************/
/* Automatically generated.  Do not edit */
/* See the mkopcodeh.awk script for details */
#define OP_VNext                                1
#define OP_Affinity                             2
#define OP_Column                               3
#define OP_SetCookie                            4
#define OP_Real                               125   /* same as TK_FLOAT    */
#define OP_Real                               126   /* same as TK_FLOAT    */
#define OP_Sequence                             5
#define OP_MoveGt                               6
#define OP_Ge                                  72   /* same as TK_GE       */
#define OP_RowKey                               7
#define OP_SCopy                                8
#define OP_Eq                                  68   /* same as TK_EQ       */
#define OP_OpenWrite                            9
#define OP_NotNull                             66   /* same as TK_NOTNULL  */
#define OP_If                                  10
#define OP_ToInt                              141   /* same as TK_TO_INT   */
#define OP_ToInt                              142   /* same as TK_TO_INT   */
#define OP_String8                             88   /* same as TK_STRING   */
#define OP_VRowid                              11
#define OP_CollSeq                             12
#define OP_OpenRead                            13
#define OP_Expire                              14
#define OP_AutoCommit                          15
#define OP_Gt                                  69   /* same as TK_GT       */

#define OP_RowData                             44
#define OP_MemMax                              45
#define OP_Or                                  60   /* same as TK_OR       */
#define OP_NotExists                           46
#define OP_Gosub                               47
#define OP_Divide                              81   /* same as TK_SLASH    */
#define OP_Integer                             48
#define OP_ToNumeric                          140   /* same as TK_TO_NUMERIC*/
#define OP_ToNumeric                          141   /* same as TK_TO_NUMERIC*/
#define OP_Prev                                49
#define OP_Concat                              83   /* same as TK_CONCAT   */
#define OP_BitAnd                              74   /* same as TK_BITAND   */
#define OP_VColumn                             50
#define OP_CreateTable                         51
#define OP_Last                                52
#define OP_IsNull                              65   /* same as TK_ISNULL   */

#define OP_IdxGE                               63
#define OP_IdxDelete                           64
#define OP_Vacuum                              73
#define OP_MoveLe                              84
#define OP_IfNot                               85
#define OP_DropTable                           86
#define OP_MakeRecord                          89
#define OP_ToBlob                             139   /* same as TK_TO_BLOB  */
#define OP_ToBlob                             140   /* same as TK_TO_BLOB  */
#define OP_ResultRow                           90
#define OP_Delete                              91
#define OP_AggFinal                            92
#define OP_Compare                             93
#define OP_ShiftLeft                           76   /* same as TK_LSHIFT   */
#define OP_Goto                                94
#define OP_TableLock                           95
#define OP_FifoRead                            96
#define OP_Clear                               97
#define OP_MoveLt                              98
#define OP_Le                                  70   /* same as TK_LE       */
#define OP_VerifyCookie                        99
#define OP_AggStep                            100
#define OP_ToText                             138   /* same as TK_TO_TEXT  */
#define OP_ToText                             139   /* same as TK_TO_TEXT  */
#define OP_Not                                 16   /* same as TK_NOT      */
#define OP_ToReal                             142   /* same as TK_TO_REAL  */
#define OP_ToReal                             143   /* same as TK_TO_REAL  */
#define OP_SetNumColumns                      101
#define OP_Transaction                        102
#define OP_VFilter                            103
#define OP_Ne                                  67   /* same as TK_NE       */
#define OP_VDestroy                           104
#define OP_ContextPop                         105
#define OP_BitOr                               75   /* same as TK_BITOR    */

#define OP_Rewind                             119
#define OP_MoveGe                             120
#define OP_VBegin                             121
#define OP_VUpdate                            122
#define OP_IfZero                             123
#define OP_BitNot                              87   /* same as TK_BITNOT   */
#define OP_VCreate                            124
#define OP_Found                              126
#define OP_Found                              125
#define OP_IfPos                              127
#define OP_NullRow                            128
#define OP_Jump                               129
#define OP_Permutation                        130

/* The following opcode values are never used */
#define OP_NotUsed_131                        131
#define OP_NotUsed_132                        132
#define OP_NotUsed_133                        133
#define OP_NotUsed_134                        134
#define OP_NotUsed_135                        135
#define OP_NotUsed_136                        136
#define OP_NotUsed_137                        137
#define OP_NotUsed_138                        138


/* Properties such as "out2" or "jump" that are specified in
** comments following the "case" for each opcode in the vdbe.c
** are encoded into bitvectors as follows:
*/
#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */

/*  64 */ 0x00, 0x05, 0x05, 0x15, 0x15, 0x15, 0x15, 0x15,\
/*  72 */ 0x15, 0x00, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,\
/*  80 */ 0x2c, 0x2c, 0x2c, 0x2c, 0x11, 0x05, 0x00, 0x04,\
/*  88 */ 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00,\
/*  96 */ 0x01, 0x00, 0x11, 0x00, 0x00, 0x00, 0x00, 0x01,\
/* 104 */ 0x00, 0x00, 0x01, 0x08, 0x00, 0x02, 0x02, 0x05,\
/* 112 */ 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x02, 0x01,\
/* 120 */ 0x11, 0x00, 0x00, 0x05, 0x00, 0x02, 0x11, 0x05,\
/* 120 */ 0x11, 0x00, 0x00, 0x05, 0x00, 0x11, 0x02, 0x05,\
/* 128 */ 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 136 */ 0x00, 0x00, 0x04, 0x04, 0x04, 0x04, 0x04,}
/* 136 */ 0x00, 0x00, 0x00, 0x04, 0x04, 0x04, 0x04, 0x04,\
}

/************** End of opcodes.h *********************************************/
/************** Continuing where we left off in vdbe.h ***********************/

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.

SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe*);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE   void sqlite3VdbeTrace(Vdbe*,FILE*);
#endif
SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, int);
SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe*);
SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n);
SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*);

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
SQLITE_PRIVATE int sqlite3VdbeReleaseMemory(int);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.83 2008/09/18 17:34:44 danielk1977 Exp $
** @(#) $Id: pager.h,v 1.86 2008/10/17 18:51:53 danielk1977 Exp $
*/

#ifndef _PAGER_H_
#define _PAGER_H_

/*
** If defined as non-zero, auto-vacuum is enabled by default. Otherwise

/*
** Valid values for the second argument to sqlite3PagerJournalMode().
*/
#define PAGER_JOURNALMODE_QUERY      -1
#define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
#define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */
#define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */
#define PAGER_JOURNALMODE_TRUNCATE    3   /* Commit by truncating journal */
#define PAGER_JOURNALMODE_MEMORY      4   /* In-memory journal file */

/*
** See source code comments for a detailed description of the following
** routines:
*/
SQLITE_PRIVATE int sqlite3PagerOpen(sqlite3_vfs *, Pager **ppPager, const char*, void(*)(DbPage*), int,int,int);
SQLITE_PRIVATE int sqlite3PagerOpen(sqlite3_vfs *, Pager **ppPager, const char*, int,int,int);
SQLITE_PRIVATE void sqlite3PagerSetBusyhandler(Pager*, BusyHandler *pBusyHandler);
SQLITE_PRIVATE void sqlite3PagerSetReiniter(Pager*, void(*)(DbPage*));
SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u16*);
SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager*, int);
SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int);
SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager);
SQLITE_PRIVATE int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage*);
SQLITE_PRIVATE int sqlite3PagerRef(DbPage*);
SQLITE_PRIVATE int sqlite3PagerUnref(DbPage*);
SQLITE_PRIVATE int sqlite3PagerWrite(DbPage*);
SQLITE_PRIVATE int sqlite3PagerPagecount(Pager*, int*);
SQLITE_PRIVATE int sqlite3PagerTruncate(Pager*,Pgno);
SQLITE_PRIVATE int sqlite3PagerBegin(DbPage*, int exFlag);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, Pgno, int);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem. 
**
** @(#) $Id: pcache.h,v 1.11 2008/09/18 17:34:44 danielk1977 Exp $
** @(#) $Id: pcache.h,v 1.14 2008/10/17 18:51:53 danielk1977 Exp $
*/

#ifndef _PCACHE_H_

typedef struct PgHdr PgHdr;
typedef struct PCache PCache;

  u16 flags;                     /* PGHDR flags defined below */
  /**********************************************************************
  ** Elements above are public.  All that follows is private to pcache.c
  ** and should not be accessed by other modules.
  */
  i16 nRef;                      /* Number of users of this page */
  PCache *pCache;                /* Cache that owns this page */
  void *apSave[2];               /* Journal entries for in-memory databases */

  /**********************************************************************
  ** Elements above are accessible at any time by the owner of the cache
  ** without the need for a mutex.  The elements that follow can only be
  ** accessed while holding the SQLITE_MUTEX_STATIC_LRU mutex.
  */
  PgHdr *pNextHash, *pPrevHash;  /* Hash collision chain for PgHdr.pgno */
  PgHdr *pNext, *pPrev;          /* List of clean or dirty pages */

** Under memory stress, invoke xStress to try to make pages clean.
** Only clean and unpinned pages can be reclaimed.
*/
SQLITE_PRIVATE void sqlite3PcacheOpen(
  int szPage,                    /* Size of every page */
  int szExtra,                   /* Extra space associated with each page */
  int bPurgeable,                /* True if pages are on backing store */
  void (*xDestroy)(PgHdr *),     /* Called to destroy a page */
  int (*xStress)(void*, PgHdr*), /* Call to try to make pages clean */
  void *pStress,                 /* Argument to xStress */
  PCache *pToInit                /* Preallocated space for the PCache */
);

/* Modify the page-size after the cache has been created. */
SQLITE_PRIVATE void sqlite3PcacheSetPageSize(PCache *, int);

/* Change a page number.  Used by incr-vacuum. */
SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr*, Pgno);

/* Remove all pages with pgno>x.  Reset the cache if x==0 */
SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache*, Pgno x);

/* Routines used to implement transactions on memory-only databases. */
SQLITE_PRIVATE int sqlite3PcachePreserve(PgHdr*, int);    /* Preserve current page content */
SQLITE_PRIVATE void sqlite3PcacheCommit(PCache*, int);    /* Drop preserved copy */
SQLITE_PRIVATE void sqlite3PcacheRollback(PCache*, int, void (*xReiniter)(PgHdr*));

/* Get a list of all dirty pages in the cache, sorted by page number */
SQLITE_PRIVATE PgHdr *sqlite3PcacheDirtyList(PCache*);

/* Reset and close the cache object */
SQLITE_PRIVATE void sqlite3PcacheClose(PCache*);

/* Clear flags from pages of the page cache */

SQLITE_PRIVATE int sqlite3PcacheClear(PCache*);

/* Return the total number of outstanding page references */
SQLITE_PRIVATE int sqlite3PcacheRefCount(PCache*);

/* Increment the reference count of an existing page */
SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr*);

SQLITE_PRIVATE int sqlite3PcachePageRefcount(PgHdr*);

/* Return the total number of pages stored in the cache */
SQLITE_PRIVATE int sqlite3PcachePagecount(PCache*);

#ifdef SQLITE_CHECK_PAGES
/* Iterate through all pages currently stored in the cache. This interface
** is only available if SQLITE_CHECK_PAGES is defined when the library is 
** built.
*/
SQLITE_PRIVATE void sqlite3PcacheIterate(PCache *pCache, void (*xIter)(PgHdr *));
#endif

/* Set and get the suggested cache-size for the specified pager-cache.
**
** If no global maximum is configured, then the system attempts to limit
** the total number of pages cached by purgeable pager-caches to the sum
** of the suggested cache-sizes.
*/
SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *);
SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *, int);

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/* Try to return memory used by the pcache module to the main memory heap */
SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int);
#endif

#ifdef SQLITE_TEST
SQLITE_PRIVATE void sqlite3PcacheStats(int*,int*,int*,int*);
#endif

#endif /* _PCACHE_H_ */

/************** End of pcache.h **********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/

/************** Include os.h in the middle of sqliteInt.h ********************/

** to all source files.  We break it out in an effort to keep the code
** better organized.
**
** NOTE:  source files should *not* #include this header file directly.
** Source files should #include the sqliteInt.h file and let that file
** include this one indirectly.
**
** $Id: mutex.h,v 1.8 2008/06/26 10:41:19 danielk1977 Exp $
** $Id: mutex.h,v 1.9 2008/10/07 15:25:48 drh Exp $
*/


#ifdef SQLITE_MUTEX_APPDEF
/*
** If SQLITE_MUTEX_APPDEF is defined, then this whole module is
** omitted and equivalent functionality must be provided by the
** application that links against the SQLite library.
*/
#else
/*
** Figure out what version of the code to use.  The choices are
**
**   SQLITE_MUTEX_NOOP         For single-threaded applications that
**                             do not desire error checking.
**   SQLITE_MUTEX_OMIT         No mutex logic.  Not even stubs.  The
**                             mutexes implemention cannot be overridden
**                             at start-time.
**
**   SQLITE_MUTEX_NOOP_DEBUG   For single-threaded applications with
**                             error checking to help verify that mutexes
**                             are being used correctly even though they
**   SQLITE_MUTEX_NOOP         For single-threaded applications.  No
**                             mutual exclusion is provided.  But this
**                             implementation can be overridden at
**                             are not needed.  Used when SQLITE_DEBUG is
**                             defined on single-threaded builds.
**                             start-time.
**
**   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
**
**   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.
**
**   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.
*/
#define SQLITE_MUTEX_NOOP 1   /* The default */
#if defined(SQLITE_DEBUG) && !SQLITE_THREADSAFE
#if !SQLITE_THREADSAFE
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_NOOP_DEBUG
# define SQLITE_MUTEX_OMIT
#endif
#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_UNIX
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_PTHREADS
#if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP)
#  if SQLITE_OS_UNIX
#    define SQLITE_MUTEX_PTHREADS
#endif
#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_WIN
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_W32
#  elif SQLITE_OS_WIN
#    define SQLITE_MUTEX_W32
#endif
#if defined(SQLITE_MUTEX_NOOP) && SQLITE_THREADSAFE && SQLITE_OS_OS2
# undef SQLITE_MUTEX_NOOP
# define SQLITE_MUTEX_OS2
#  elif SQLITE_OS_OS2
#    define SQLITE_MUTEX_OS2
#  else
#    define SQLITE_MUTEX_NOOP
#  endif
#endif

#ifdef SQLITE_MUTEX_NOOP
#ifdef SQLITE_MUTEX_OMIT
/*
** If this is a no-op implementation, implement everything as macros.
*/
#define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)
#define sqlite3_mutex_free(X)
#define sqlite3_mutex_enter(X)
#define sqlite3_mutex_try(X)      SQLITE_OK
#define sqlite3_mutex_leave(X)
#define sqlite3_mutex_held(X)     1
#define sqlite3_mutex_notheld(X)  1
#define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)
#define sqlite3MutexInit()        SQLITE_OK
#define sqlite3MutexEnd()
#endif
#endif /* defined(SQLITE_OMIT_MUTEX) */

#endif /* SQLITE_MUTEX_APPDEF */

/************** End of mutex.h ***********************************************/
/************** Continuing where we left off in sqliteInt.h ******************/


/*
** Each database file to be accessed by the system is an instance

    int newTnum;                /* Rootpage of table being initialized */
    u8 busy;                    /* TRUE if currently initializing */
  } init;
  int nExtension;               /* Number of loaded extensions */
  void **aExtension;            /* Array of shared libraray handles */
  struct Vdbe *pVdbe;           /* List of active virtual machines */
  int activeVdbeCnt;            /* Number of vdbes currently executing */
  int writeVdbeCnt;             /* Number of active VDBEs that are writing */
  void (*xTrace)(void*,const char*);        /* Trace function */
  void *pTraceArg;                          /* Argument to the trace function */
  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
  void *pProfileArg;                        /* Argument to profile function */
  void *pCommitArg;                 /* Argument to xCommitCallback() */   
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */   

/*
** Each SQL function is defined by an instance of the following
** structure.  A pointer to this structure is stored in the sqlite.aFunc
** hash table.  When multiple functions have the same name, the hash table
** points to a linked list of these structures.
*/
struct FuncDef {
  i8 nArg;             /* Number of arguments.  -1 means unlimited */
  i16 nArg;            /* Number of arguments.  -1 means unlimited */
  u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
  u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
  u8 flags;            /* Some combination of SQLITE_FUNC_* */
  void *pUserData;     /* User data parameter */
  FuncDef *pNext;      /* Next function with same name */
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
  void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
  char *zName;         /* SQL name of the function. */
  FuncDef *pHash;      /* Next with a different name but the same hash */
};

/*
** Possible values for FuncDef.flags
*/
#define SQLITE_FUNC_LIKE     0x01  /* Candidate for the LIKE optimization */
#define SQLITE_FUNC_CASE     0x02  /* Case-sensitive LIKE-type function */
#define SQLITE_FUNC_EPHEM    0x04  /* Ephermeral.  Delete with VDBE */
#define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
#define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
#define SQLITE_FUNC_EPHEM    0x04 /* Ephermeral.  Delete with VDBE */
#define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */

/*
** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
** used to create the initializers for the FuncDef structures.
**
**   FUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Used to create a scalar function definition of a function zName 

**     that accepts nArg arguments and is implemented by a call to C 
**     function likeFunc. Argument pArg is cast to a (void *) and made
**     available as the function user-data (sqlite3_user_data()). The
**     FuncDef.flags variable is set to the value passed as the flags
**     parameter.
*/
#define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
  {nArg, SQLITE_UTF8, bNC, 0, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName}
  {nArg, SQLITE_UTF8, bNC*8, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName}
#define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
  {nArg, SQLITE_UTF8, bNC*8, pArg, 0, xFunc, 0, 0, #zName}
#define LIKEFUNC(zName, nArg, arg, flags) \
  {nArg, SQLITE_UTF8, 0, flags, (void *)arg, 0, likeFunc, 0, 0, #zName}
  {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName}
#define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
  {nArg, SQLITE_UTF8, nc, 0, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal, #zName}
  {nArg, SQLITE_UTF8, nc*8, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal, #zName}


/*
** Each SQLite module (virtual table definition) is defined by an
** instance of the following structure, stored in the sqlite3.aModule
** hash table.
*/

    Select *pSelect;  /* A SELECT statement used in place of a table name */
    u8 isPopulated;   /* Temporary table associated with SELECT is populated */
    u8 jointype;      /* Type of join between this able and the previous */
    int iCursor;      /* The VDBE cursor number used to access this table */
    Expr *pOn;        /* The ON clause of a join */
    IdList *pUsing;   /* The USING clause of a join */
    Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
    u8 notIndexed;    /* True if there is a NOT INDEXED clause */
    char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
    Index *pIndex;    /* Index structure corresponding to zIndex, if any */
  } a[1];             /* One entry for each identifier on the list */
};

/*
** Permitted values of the SrcList.a.jointype field
*/
#define JT_INNER     0x0001    /* Any kind of inner or cross join */

  Index *pIdx;          /* Index used.  NULL if no index */
  int iTabCur;          /* The VDBE cursor used to access the table */
  int iIdxCur;          /* The VDBE cursor used to acesss pIdx */
  int brk;              /* Jump here to break out of the loop */
  int nxt;              /* Jump here to start the next IN combination */
  int cont;             /* Jump here to continue with the next loop cycle */
  int top;              /* First instruction of interior of the loop */
  int op, p1, p2;       /* Opcode used to terminate the loop */
  int op, p1, p2, p5;   /* Opcode used to terminate the loop */
  int nEq;              /* Number of == or IN constraints on this loop */
  int nIn;              /* Number of IN operators constraining this loop */
  struct InLoop {
    int iCur;              /* The VDBE cursor used by this IN operator */
    int topAddr;           /* Top of the IN loop */
  } *aInLoop;           /* Information about each nested IN operator */
  sqlite3_index_info *pBestIdx;  /* Index information for this level */

  int szPage;                       /* Size of each page in pPage[] */
  int nPage;                        /* Number of pages in pPage[] */
  int isInit;                       /* True after initialization has finished */
  int inProgress;                   /* True while initialization in progress */
  int isMallocInit;                 /* True after malloc is initialized */
  sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
  int nRefInitMutex;                /* Number of users of pInitMutex */
  int nSmall;                       /* alloc size threshold used by mem6.c */
  int mxParserStack;                /* maximum depth of the parser stack */
  int sharedCacheEnabled;           /* true if shared-cache mode enabled */
};

/*
** Context pointer passed down through the tree-walk.
*/

SQLITE_PRIVATE int sqlite3MallocSize(void*);
SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3*, void*);
SQLITE_PRIVATE void *sqlite3ScratchMalloc(int);
SQLITE_PRIVATE void sqlite3ScratchFree(void*);
SQLITE_PRIVATE void *sqlite3PageMalloc(int);
SQLITE_PRIVATE void sqlite3PageFree(void*);
SQLITE_PRIVATE void sqlite3MemSetDefault(void);
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetDefault(void);
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys6(void);
SQLITE_PRIVATE void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
SQLITE_PRIVATE int sqlite3MemoryAlarm(void (*)(void*, sqlite3_int64, int), void*, sqlite3_int64);

#ifndef SQLITE_MUTEX_NOOP
#ifndef SQLITE_MUTEX_OMIT
SQLITE_PRIVATE   sqlite3_mutex_methods *sqlite3DefaultMutex(void);
SQLITE_PRIVATE   sqlite3_mutex *sqlite3MutexAlloc(int);
SQLITE_PRIVATE   int sqlite3MutexInit(void);
SQLITE_PRIVATE   int sqlite3MutexEnd(void);
#endif

SQLITE_PRIVATE int sqlite3StatusValue(int);

SQLITE_PRIVATE Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
SQLITE_PRIVATE Expr *sqlite3RegisterExpr(Parse*,Token*);
SQLITE_PRIVATE Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
SQLITE_PRIVATE void sqlite3ExprSpan(Expr*,Token*,Token*);
SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3ExprClear(sqlite3*, Expr*);
SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3*, Expr*);
SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3*, ExprList*);
SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);
SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
SQLITE_PRIVATE void sqlite3ResetInternalSchema(sqlite3*, int);

SQLITE_PRIVATE void sqlite3DropTable(Parse*, SrcList*, int, int);
SQLITE_PRIVATE void sqlite3DeleteTable(Table*);
SQLITE_PRIVATE void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
SQLITE_PRIVATE void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
SQLITE_PRIVATE IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
SQLITE_PRIVATE int sqlite3IdListIndex(IdList*,const char*);
SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, Token*,
                                      Select*, Expr*, IdList*);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
                                      Token*, Select*, Expr*, IdList*);
SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList*);
SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);
SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3*, IdList*);
SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3*, SrcList*);
SQLITE_PRIVATE void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                        Token*, int, int);
SQLITE_PRIVATE void sqlite3DropIndex(Parse*, SrcList*, int);
SQLITE_PRIVATE int sqlite3Select(Parse*, Select*, SelectDest*);
SQLITE_PRIVATE Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,int,Expr*,Expr*);
SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3*, Select*);
SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse*, SrcList*);
SQLITE_PRIVATE int sqlite3IsReadOnly(Parse*, Table*, int);
SQLITE_PRIVATE void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
SQLITE_PRIVATE Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
#endif
SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo*);
SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse*, int, int, int);
SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse*, int, int, int);

SQLITE_PRIVATE void sqlite3RootPageMoved(Db*, int, int);
SQLITE_PRIVATE void sqlite3Reindex(Parse*, Token*, Token*);
SQLITE_PRIVATE void sqlite3AlterFunctions(sqlite3*);
SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *, int *);
SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);
SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*);
SQLITE_PRIVATE void sqlite3CodeSubselect(Parse *, Expr *, int);
SQLITE_PRIVATE void sqlite3CodeSubselect(Parse *, Expr *, int, int);
SQLITE_PRIVATE void sqlite3SelectPrep(Parse*, Select*, NameContext*);
SQLITE_PRIVATE int sqlite3ResolveExprNames(NameContext*, Expr*);
SQLITE_PRIVATE void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *, Table *, int);
SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *, Token *);
SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
SQLITE_PRIVATE char sqlite3AffinityType(const Token*);
SQLITE_PRIVATE void sqlite3Analyze(Parse*, Token*, Token*);
SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler*);
SQLITE_PRIVATE int sqlite3FindDb(sqlite3*, Token*);
SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3*,int iDB);
SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);
SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);
SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
SQLITE_PRIVATE void sqlite3AttachFunctions(sqlite3 *);
SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse*, int, int);
SQLITE_PRIVATE void sqlite3SchemaFree(void *);
SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
SQLITE_PRIVATE KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
  void (*)(sqlite3_context*,int,sqlite3_value **),

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
SQLITE_PRIVATE   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
SQLITE_PRIVATE   int sqlite3JournalSize(sqlite3_vfs *);
SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);
#else
  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
#endif

SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *);
SQLITE_PRIVATE int sqlite3MemJournalSize();
SQLITE_PRIVATE int sqlite3IsMemJournal(sqlite3_file *);

#if SQLITE_MAX_EXPR_DEPTH>0
SQLITE_PRIVATE   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
SQLITE_PRIVATE   int sqlite3SelectExprHeight(Select *);
SQLITE_PRIVATE   int sqlite3ExprCheckHeight(Parse*, int);
#else
  #define sqlite3ExprSetHeight(x,y)

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.90 2008/09/03 17:11:16 drh Exp $
** $Id: date.c,v 1.92 2008/10/13 15:35:09 drh Exp $
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5

      if( strcmp(z, "unixepoch")==0 && p->validJD ){
        p->iJD = p->iJD/86400.0 + 2440587.5*86400000.0;
        clearYMD_HMS_TZ(p);
        rc = 0;
      }
#ifndef SQLITE_OMIT_LOCALTIME
      else if( strcmp(z, "utc")==0 ){
        double c1;
        int c1;
        computeJD(p);
        c1 = localtimeOffset(p);
        p->iJD -= c1;
        clearYMD_HMS_TZ(p);
        p->iJD += c1 - localtimeOffset(p);
        rc = 0;
      }

    FUNCTION(time,             -1, 0, 0, timeFunc      ),
    FUNCTION(datetime,         -1, 0, 0, datetimeFunc  ),
    FUNCTION(strftime,         -1, 0, 0, strftimeFunc  ),
    FUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
    FUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
    FUNCTION(current_date,      0, 0, 0, cdateFunc     ),
#else
    FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),
    FUNCTION(current_timestamp, 0, "%Y-%m-%d",          0, currentTimeFunc),
    FUNCTION(current_date,      0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
    STR_FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),
    STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d",          0, currentTimeFunc),
    STR_FUNCTION(current_date,      0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
#endif
  };
  int i;
  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aDateTimeFuncs);

  for(i=0; i<ArraySize(aDateTimeFuncs); i++){

**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains OS interface code that is common to all
** architectures.
**
** $Id: os.c,v 1.122 2008/09/02 17:18:52 danielk1977 Exp $
** $Id: os.c,v 1.124 2008/10/07 15:25:48 drh Exp $
*/
#define _SQLITE_OS_C_ 1
#undef _SQLITE_OS_C_

/*
** The default SQLite sqlite3_vfs implementations do not allocate
** memory (actually, os_unix.c allocates a small amount of memory

**     sqlite3OsOpen()
**     sqlite3OsRead()
**     sqlite3OsWrite()
**     sqlite3OsSync()
**     sqlite3OsLock()
**
*/
#if defined(SQLITE_TEST) && (SQLITE_OS_WIN==0) && 0
#if defined(SQLITE_TEST) && (SQLITE_OS_WIN==0)
  #define DO_OS_MALLOC_TEST if (1) {            \
    void *pTstAlloc = sqlite3Malloc(10);       \
    if (!pTstAlloc) return SQLITE_IOERR_NOMEM;  \
    sqlite3_free(pTstAlloc);                    \
  }
#else
  #define DO_OS_MALLOC_TEST

/*
** Locate a VFS by name.  If no name is given, simply return the
** first VFS on the list.
*/
SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
  sqlite3_vfs *pVfs = 0;
#ifndef SQLITE_MUTEX_NOOP
#if SQLITE_THREADSAFE
  sqlite3_mutex *mutex;
#endif
#ifndef SQLITE_OMIT_AUTOINIT
  int rc = sqlite3_initialize();
  if( rc ) return 0;
#endif
#ifndef SQLITE_MUTEX_NOOP
#if SQLITE_THREADSAFE
  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
  sqlite3_mutex_enter(mutex);
  for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){
    if( zVfs==0 ) break;
    if( strcmp(zVfs, pVfs->zName)==0 ) break;
  }

  return SQLITE_OK;
}

/*
** Unregister a VFS so that it is no longer accessible.
*/
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
#ifndef SQLITE_MUTEX_NOOP
#if SQLITE_THREADSAFE
  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
  sqlite3_mutex_enter(mutex);
  vfsUnlink(pVfs);
  sqlite3_mutex_leave(mutex);
  return SQLITE_OK;
}

    wsdHooks.xBenignEnd();
  }
}

#endif   /* #ifndef SQLITE_OMIT_BUILTIN_TEST */

/************** End of fault.c ***********************************************/
/************** Begin file mem0.c ********************************************/
/*
** 2008 October 28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains a no-op memory allocation drivers for use when
** SQLITE_ZERO_MALLOC is defined.  The allocation drivers implemented
** here always fail.  SQLite will not operate with these drivers.  These
** are merely placeholders.  Real drivers must be substituted using
** sqlite3_config() before SQLite will operate.
**
** $Id: mem0.c,v 1.1 2008/10/28 18:58:20 drh Exp $
*/

/*
** This version of the memory allocator is the default.  It is
** used when no other memory allocator is specified using compile-time
** macros.
*/
#ifdef SQLITE_ZERO_MALLOC

/*
** No-op versions of all memory allocation routines
*/
static void *sqlite3MemMalloc(int nByte){ return 0; }
static void sqlite3MemFree(void *pPrior){ return; }
static void *sqlite3MemRealloc(void *pPrior, int nByte){ return 0; }
static int sqlite3MemSize(void *pPrior){ return 0; }
static int sqlite3MemRoundup(int n){ return n; }
static int sqlite3MemInit(void *NotUsed){ return SQLITE_OK; }
static void sqlite3MemShutdown(void *NotUsed){ return; }

/*
** This routine is the only routine in this file with external linkage.
**
** Populate the low-level memory allocation function pointers in
** sqlite3GlobalConfig.m with pointers to the routines in this file.
*/
SQLITE_PRIVATE void sqlite3MemSetDefault(void){
  static const sqlite3_mem_methods defaultMethods = {
     sqlite3MemMalloc,
     sqlite3MemFree,
     sqlite3MemRealloc,
     sqlite3MemSize,
     sqlite3MemRoundup,
     sqlite3MemInit,
     sqlite3MemShutdown,
     0
  };
  sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);
}

#endif /* SQLITE_ZERO_MALLOC */

/************** End of mem0.c ************************************************/
/************** Begin file mem1.c ********************************************/
/*
** 2007 August 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains low-level memory allocation drivers for when
** SQLite will use the standard C-library malloc/realloc/free interface
** to obtain the memory it needs.
**
** This file contains implementations of the low-level memory allocation
** routines specified in the sqlite3_mem_methods object.
**
** $Id: mem1.c,v 1.26 2008/09/01 18:34:20 danielk1977 Exp $
** $Id: mem1.c,v 1.27 2008/10/28 18:58:20 drh Exp $
*/

/*
** This version of the memory allocator is the default.  It is
** used when no other memory allocator is specified using compile-time
** macros.
*/

/*
** Deinitialize this module.
*/
static void sqlite3MemShutdown(void *NotUsed){
  return;
}

/*
** This routine is the only routine in this file with external linkage.
**
** Populate the low-level memory allocation function pointers in
** sqlite3GlobalConfig.m with pointers to the routines in this file.
*/
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetDefault(void){
SQLITE_PRIVATE void sqlite3MemSetDefault(void){
  static const sqlite3_mem_methods defaultMethods = {
     sqlite3MemMalloc,
     sqlite3MemFree,
     sqlite3MemRealloc,
     sqlite3MemSize,
     sqlite3MemRoundup,
     sqlite3MemInit,
     sqlite3MemShutdown,
     0
  };
  return &defaultMethods;
}

/*
** This routine is the only routine in this file with external linkage.
**
** Populate the low-level memory allocation function pointers in
** sqlite3GlobalConfig.m with pointers to the routines in this file.
*/
SQLITE_PRIVATE void sqlite3MemSetDefault(void){
  sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetDefault());
  sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);
}

#endif /* SQLITE_SYSTEM_MALLOC */

/************** End of mem1.c ************************************************/
/************** Begin file mem2.c ********************************************/
/*

** to obtain the memory it needs while adding lots of additional debugging
** information to each allocation in order to help detect and fix memory
** leaks and memory usage errors.
**
** This file contains implementations of the low-level memory allocation
** routines specified in the sqlite3_mem_methods object.
**
** $Id: mem2.c,v 1.39 2008/09/01 18:34:20 danielk1977 Exp $
** $Id: mem2.c,v 1.40 2008/10/28 18:58:20 drh Exp $
*/

/*
** This version of the memory allocator is used only if the
** SQLITE_MEMDEBUG macro is defined
*/
#ifdef SQLITE_MEMDEBUG

      memset(&((char*)pNew)[pOldHdr->iSize], 0x2b, nByte - pOldHdr->iSize);
    }
    sqlite3MemFree(pPrior);
  }
  return pNew;
}


SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetDefault(void){
/*
** Populate the low-level memory allocation function pointers in
** sqlite3GlobalConfig.m with pointers to the routines in this file.
*/
SQLITE_PRIVATE void sqlite3MemSetDefault(void){
  static const sqlite3_mem_methods defaultMethods = {
     sqlite3MemMalloc,
     sqlite3MemFree,
     sqlite3MemRealloc,
     sqlite3MemSize,
     sqlite3MemRoundup,
     sqlite3MemInit,
     sqlite3MemShutdown,
     0
  };
  return &defaultMethods;
}

/*
** Populate the low-level memory allocation function pointers in
** sqlite3GlobalConfig.m with pointers to the routines in this file.
*/
SQLITE_PRIVATE void sqlite3MemSetDefault(void){
  sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetDefault());
  sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);
}

/*
** Set the number of backtrace levels kept for each allocation.
** A value of zero turns off backtracing.  The number is always rounded
** up to a multiple of 2.
*/

** implementations. Once sqlite3_initialize() has been called,
** the amount of memory available to SQLite is fixed and cannot
** be changed.
**
** This version of the memory allocation subsystem is included
** in the build only if SQLITE_ENABLE_MEMSYS5 is defined.
**
** $Id: mem5.c,v 1.14 2008/09/02 17:52:52 danielk1977 Exp $
** $Id: mem5.c,v 1.15 2008/10/28 18:58:20 drh Exp $
*/

/*
** This version of the memory allocator is used only when 
** SQLITE_POW2_MEMORY_SIZE is defined.
** SQLITE_ENABLE_MEMSYS5 is defined.
*/
#ifdef SQLITE_ENABLE_MEMSYS5

/*
** Log2 of the minimum size of an allocation.  For example, if
** 4 then all allocations will be rounded up to at least 16 bytes.
** If 5 then all allocations will be rounded up to at least 32 bytes.
*/
#ifndef SQLITE_POW2_LOGMIN
# define SQLITE_POW2_LOGMIN 6
#endif

/*
** Log2 of the maximum size of an allocation.
*/
#ifndef SQLITE_POW2_LOGMAX
# define SQLITE_POW2_LOGMAX 20
#endif
#define POW2_MAX (((unsigned int)1)<<SQLITE_POW2_LOGMAX)

/*
** Number of distinct allocation sizes.
*/
#define NSIZE (SQLITE_POW2_LOGMAX - SQLITE_POW2_LOGMIN + 1)

/*
** A minimum allocation is an instance of the following structure.
** Larger allocations are an array of these structures where the
** size of the array is a power of 2.
*/
typedef struct Mem5Link Mem5Link;
struct Mem5Link {

  };
  return &memsys5Methods;
}

#endif /* SQLITE_ENABLE_MEMSYS5 */

/************** End of mem5.c ************************************************/
/************** Begin file mem6.c ********************************************/
/*
** 2008 July 24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains an alternative memory allocation system for SQLite.
** This system is implemented as a wrapper around the system provided
** by the operating system - vanilla malloc(), realloc() and free().
**
** This system differentiates between requests for "small" allocations 
** (by default those of 128 bytes or less) and "large" allocations (all
** others). The 256 byte threshhold is configurable at runtime.
**
** All requests for large allocations are passed through to the 
** default system.
**
** Requests for small allocations are met by allocating space within
** one or more larger "chunks" of memory obtained from the default
** memory allocation system. Chunks of memory are usually 64KB or 
** larger. The algorithm used to manage space within each chunk is
** the same as that used by mem5.c. 
**
** This strategy is designed to prevent the default memory allocation
** system (usually the system malloc) from suffering from heap 
** fragmentation. On some systems, heap fragmentation can cause a 
** significant real-time slowdown.
**
** $Id: mem6.c,v 1.10 2008/09/02 17:52:52 danielk1977 Exp $
*/

#ifdef SQLITE_ENABLE_MEMSYS6


/*
** Maximum size of any "small" allocation is ((1<<LOGMAX)*Mem6Chunk.nAtom).
** Mem6Chunk.nAtom is always at least 8, so this is not a practical
** limitation
*/
#define LOGMAX 30

/*
** Default value for the "small" allocation size threshold.
*/
#define SMALL_MALLOC_DEFAULT_THRESHOLD 256

/*
** Minimum size for a memory chunk.
*/
#define MIN_CHUNKSIZE (1<<16)

#define LOG2_MINALLOC 4


typedef struct Mem6Chunk Mem6Chunk;
typedef struct Mem6Link Mem6Link;

/*
** A minimum allocation is an instance of the following structure.
** Larger allocations are an array of these structures where the
** size of the array is a power of 2.
*/
struct Mem6Link {
  int next;       /* Index of next free chunk */
  int prev;       /* Index of previous free chunk */
};

/*
** Masks used for mem5.aCtrl[] elements.
*/
#define CTRL_LOGSIZE  0x1f    /* Log2 Size of this block relative to POW2_MIN */
#define CTRL_FREE     0x20    /* True if not checked out */

struct Mem6Chunk {
  Mem6Chunk *pNext;

  /*
  ** Lists of free blocks of various sizes.
  */
  int aiFreelist[LOGMAX+1];

  int nCheckedOut; /* Number of currently outstanding allocations */

  /*
  ** Space for tracking which blocks are checked out and the size
  ** of each block. One byte per block.
  */
  u8 *aCtrl;

  /*
  ** Memory available for allocation
  */
  int nAtom;       /* Smallest possible allocation in bytes */
  int nBlock;      /* Number of nAtom sized blocks in zPool */
  u8 *zPool;       /* Pointer to memory chunk from which allocations are made */
};

#define MEM6LINK(idx) ((Mem6Link *)(&pChunk->zPool[(idx)*pChunk->nAtom]))

static SQLITE_WSD struct Mem6Global {
  int nMinAlloc;                  /* Minimum allowed allocation size */
  int nThreshold;                 /* Allocs larger than this go to malloc() */
  int nLogThreshold;              /* log2 of (nThreshold/nMinAlloc) */
  sqlite3_mutex *mutex;
  Mem6Chunk *pChunk;              /* Singly linked list of all memory chunks */
} mem6 = { 48642791 };

#define mem6 GLOBAL(struct Mem6Global, mem6)

/*
** Unlink the chunk at pChunk->aPool[i] from list it is currently
** on.  It should be found on pChunk->aiFreelist[iLogsize].
*/
static void memsys6Unlink(Mem6Chunk *pChunk, int i, int iLogsize){
  int next, prev;
  assert( i>=0 && i<pChunk->nBlock );
  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
  assert( (pChunk->aCtrl[i] & CTRL_LOGSIZE)==iLogsize );

  next = MEM6LINK(i)->next;
  prev = MEM6LINK(i)->prev;
  if( prev<0 ){
    pChunk->aiFreelist[iLogsize] = next;
  }else{
    MEM6LINK(prev)->next = next;
  }
  if( next>=0 ){
    MEM6LINK(next)->prev = prev;
  }
}

/*
** Link the chunk at mem5.aPool[i] so that is on the iLogsize
** free list.
*/
static void memsys6Link(Mem6Chunk *pChunk, int i, int iLogsize){
  int x;
  assert( i>=0 && i<pChunk->nBlock );
  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
  assert( (pChunk->aCtrl[i] & CTRL_LOGSIZE)==iLogsize );

  x = MEM6LINK(i)->next = pChunk->aiFreelist[iLogsize];
  MEM6LINK(i)->prev = -1;
  if( x>=0 ){
    assert( x<pChunk->nBlock );
    MEM6LINK(x)->prev = i;
  }
  pChunk->aiFreelist[iLogsize] = i;
}


/*
** Find the first entry on the freelist iLogsize.  Unlink that
** entry and return its index. 
*/
static int memsys6UnlinkFirst(Mem6Chunk *pChunk, int iLogsize){
  int i;
  int iFirst;

  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
  i = iFirst = pChunk->aiFreelist[iLogsize];
  assert( iFirst>=0 );
  memsys6Unlink(pChunk, iFirst, iLogsize);
  return iFirst;
}

static int roundupLog2(int n){
  static const char LogTable256[256] = {
    0,                                                    /* 1 */
    1,                                                    /* 2 */
    2, 2,                                                 /* 3..4 */
    3, 3, 3, 3,                                           /* 5..8 */
    4, 4, 4, 4, 4, 4, 4, 4,                               /* 9..16 */
    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,       /* 17..32 */
    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,       /* 33..64 */
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,       /* 65..128 */
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,       /* 129..256 */
  };

  assert(n<=(1<<16) && n>0);
  if( n<=256 ) return LogTable256[n-1];
  return LogTable256[(n>>8) - ((n&0xFF)?0:1)] + 8;
}

/*
** Allocate and return a block of (pChunk->nAtom << iLogsize) bytes from chunk
** pChunk. If the allocation request cannot be satisfied, return 0.
*/
static void *chunkMalloc(Mem6Chunk *pChunk, int iLogsize){
  int i;           /* Index of a mem5.aPool[] slot */
  int iBin;        /* Index into mem5.aiFreelist[] */

  /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
  ** block.  If not, then split a block of the next larger power of
  ** two in order to create a new free block of size iLogsize.
  */
  for(iBin=iLogsize; pChunk->aiFreelist[iBin]<0 && iBin<=mem6.nLogThreshold; iBin++){}
  if( iBin>mem6.nLogThreshold ) return 0;
  i = memsys6UnlinkFirst(pChunk, iBin);
  while( iBin>iLogsize ){
    int newSize;
    iBin--;
    newSize = 1 << iBin;
    pChunk->aCtrl[i+newSize] = CTRL_FREE | iBin;
    memsys6Link(pChunk, i+newSize, iBin);
  }
  pChunk->aCtrl[i] = iLogsize;

  /* Return a pointer to the allocated memory. */
  pChunk->nCheckedOut++;
  return (void*)&pChunk->zPool[i*pChunk->nAtom];
}

/*
** Free the allocation pointed to by p, which is guaranteed to be non-zero
** and a part of chunk object pChunk.
*/
static void chunkFree(Mem6Chunk *pChunk, void *pOld){
  u32 size, iLogsize;
  int iBlock;             

  /* Set iBlock to the index of the block pointed to by pOld in 
  ** the array of pChunk->nAtom byte blocks pointed to by pChunk->zPool.
  */
  iBlock = ((u8 *)pOld-pChunk->zPool)/pChunk->nAtom;

  /* Check that the pointer pOld points to a valid, non-free block. */
  assert( iBlock>=0 && iBlock<pChunk->nBlock );
  assert( ((u8 *)pOld-pChunk->zPool)%pChunk->nAtom==0 );
  assert( (pChunk->aCtrl[iBlock] & CTRL_FREE)==0 );

  iLogsize = pChunk->aCtrl[iBlock] & CTRL_LOGSIZE;
  size = 1<<iLogsize;
  assert( iBlock+size-1<pChunk->nBlock );

  pChunk->aCtrl[iBlock] |= CTRL_FREE;
  pChunk->aCtrl[iBlock+size-1] |= CTRL_FREE;

  pChunk->aCtrl[iBlock] = CTRL_FREE | iLogsize;
  while( iLogsize<mem6.nLogThreshold ){
    int iBuddy;
    if( (iBlock>>iLogsize) & 1 ){
      iBuddy = iBlock - size;
    }else{
      iBuddy = iBlock + size;
    }
    assert( iBuddy>=0 );
    if( (iBuddy+(1<<iLogsize))>pChunk->nBlock ) break;
    if( pChunk->aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
    memsys6Unlink(pChunk, iBuddy, iLogsize);
    iLogsize++;
    if( iBuddy<iBlock ){
      pChunk->aCtrl[iBuddy] = CTRL_FREE | iLogsize;
      pChunk->aCtrl[iBlock] = 0;
      iBlock = iBuddy;
    }else{
      pChunk->aCtrl[iBlock] = CTRL_FREE | iLogsize;
      pChunk->aCtrl[iBuddy] = 0;
    }
    size *= 2;
  }
  pChunk->nCheckedOut--;
  memsys6Link(pChunk, iBlock, iLogsize);
}

/*
** Return the actual size of the block pointed to by p, which is guaranteed
** to have been allocated from chunk pChunk.
*/
static int chunkSize(Mem6Chunk *pChunk, void *p){
  int iSize = 0;
  if( p ){
    int i = ((u8 *)p-pChunk->zPool)/pChunk->nAtom;
    assert( i>=0 && i<pChunk->nBlock );
    iSize = pChunk->nAtom * (1 << (pChunk->aCtrl[i]&CTRL_LOGSIZE));
  }
  return iSize;
}

/*
** Return true if there are currently no outstanding allocations.
*/
static int chunkIsEmpty(Mem6Chunk *pChunk){
  return (pChunk->nCheckedOut==0);
}

/*
** Initialize the buffer zChunk, which is nChunk bytes in size, as
** an Mem6Chunk object. Return a copy of the zChunk pointer.
*/
static Mem6Chunk *chunkInit(u8 *zChunk, int nChunk, int nMinAlloc){
  int ii;
  int iOffset;
  Mem6Chunk *pChunk = (Mem6Chunk *)zChunk;

  assert( nChunk>sizeof(Mem6Chunk) );
  assert( nMinAlloc>sizeof(Mem6Link) );

  memset(pChunk, 0, sizeof(Mem6Chunk));
  pChunk->nAtom = nMinAlloc;
  pChunk->nBlock = ((nChunk-sizeof(Mem6Chunk)) / (pChunk->nAtom+sizeof(u8)));

  pChunk->zPool = (u8 *)&pChunk[1];
  pChunk->aCtrl = &pChunk->zPool[pChunk->nBlock*pChunk->nAtom];

  for(ii=0; ii<=mem6.nLogThreshold; ii++){
    pChunk->aiFreelist[ii] = -1;
  }

  iOffset = 0;
  for(ii=mem6.nLogThreshold; ii>=0; ii--){
    int nAlloc = (1<<ii);
    while( (iOffset+nAlloc)<=pChunk->nBlock ){
      pChunk->aCtrl[iOffset] = ii | CTRL_FREE;
      memsys6Link(pChunk, iOffset, ii);
      iOffset += nAlloc;
    }
  }

  return pChunk;
}


static void mem6Enter(void){
  sqlite3_mutex_enter(mem6.mutex);
}

static void mem6Leave(void){
  sqlite3_mutex_leave(mem6.mutex);
}

/*
** Based on the number and size of the currently allocated chunks, return
** the size of the next chunk to allocate, in bytes.
*/
static int nextChunkSize(void){
  int iTotal = MIN_CHUNKSIZE;
  Mem6Chunk *p;
  for(p=mem6.pChunk; p; p=p->pNext){
    iTotal = iTotal*2;
  }
  return iTotal;
}

static void freeChunk(Mem6Chunk *pChunk){
  Mem6Chunk **pp = &mem6.pChunk;
  for( pp=&mem6.pChunk; *pp!=pChunk; pp = &(*pp)->pNext );
  *pp = (*pp)->pNext;
  free(pChunk);
}

static void *memsys6Malloc(int nByte){
  Mem6Chunk *pChunk;
  void *p = 0;
  int nTotal = nByte+8;
  int iOffset = 0;

  if( nTotal>mem6.nThreshold ){
    p = malloc(nTotal);
  }else{
    int iLogsize = 0;
    if( nTotal>(1<<LOG2_MINALLOC) ){
      iLogsize = roundupLog2(nTotal) - LOG2_MINALLOC;
    }
    mem6Enter();
    for(pChunk=mem6.pChunk; pChunk; pChunk=pChunk->pNext){
      p = chunkMalloc(pChunk, iLogsize);
      if( p ){
        break;
      }
    }
    if( !p ){
      int iSize = nextChunkSize();
      p = malloc(iSize);
      if( p ){
        pChunk = chunkInit((u8 *)p, iSize, mem6.nMinAlloc);
        pChunk->pNext = mem6.pChunk;
        mem6.pChunk = pChunk;
        p = chunkMalloc(pChunk, iLogsize);
        assert(p);
      }
    }
    iOffset = ((u8*)p - (u8*)pChunk);
    mem6Leave();
  }

  if( !p ){
    return 0;
  }
  ((u32 *)p)[0] = iOffset;
  ((u32 *)p)[1] = nByte;
  return &((u32 *)p)[2];
}

static int memsys6Size(void *pPrior){
  if( pPrior==0 ) return 0;
  return ((u32*)pPrior)[-1];
}

static void memsys6Free(void *pPrior){
  int iSlot;
  void *p = &((u32 *)pPrior)[-2];
  iSlot = ((u32 *)p)[0];
  if( iSlot ){
    Mem6Chunk *pChunk;
    mem6Enter();
    pChunk = (Mem6Chunk *)(&((u8 *)p)[-1 * iSlot]);
    chunkFree(pChunk, p);
    if( chunkIsEmpty(pChunk) ){
      freeChunk(pChunk);
    }
    mem6Leave();
  }else{
    free(p);
  }
}

static void *memsys6Realloc(void *p, int nByte){
  void *p2;

  if( p && nByte<=memsys6Size(p) ){
    p2 = p;
  }else{
    p2 = memsys6Malloc(nByte);
    if( p && p2 ){
      memcpy(p2, p, memsys6Size(p));
      memsys6Free(p);
    }
  }

  return p2;
}

static int memsys6Roundup(int n){
  if( n>mem6.nThreshold ){
    return n;
  }else{
    return (1<<roundupLog2(n));
  }
}

static int memsys6Init(void *pCtx){
  u8 bMemstat = sqlite3GlobalConfig.bMemstat;
  mem6.nMinAlloc = (1 << LOG2_MINALLOC);
  mem6.pChunk = 0;
  mem6.nThreshold = sqlite3GlobalConfig.nSmall;
  if( mem6.nThreshold<=0 ){
    mem6.nThreshold = SMALL_MALLOC_DEFAULT_THRESHOLD;
  }
  mem6.nLogThreshold = roundupLog2(mem6.nThreshold) - LOG2_MINALLOC;
  if( !bMemstat ){
    mem6.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
  }
  return SQLITE_OK;
}

static void memsys6Shutdown(void *pCtx){
  memset(&mem6, 0, sizeof(mem6));
}

/*
** This routine is the only routine in this file with external 
** linkage. It returns a pointer to a static sqlite3_mem_methods
** struct populated with the memsys6 methods.
*/
SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys6(void){
  static const sqlite3_mem_methods memsys6Methods = {
     memsys6Malloc,
     memsys6Free,
     memsys6Realloc,
     memsys6Size,
     memsys6Roundup,
     memsys6Init,
     memsys6Shutdown,
     0
  };
  return &memsys6Methods;
}

#endif

/************** End of mem6.c ************************************************/
/************** Begin file mutex.c *******************************************/
/*
** 2007 August 14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes.
**
** The implementation in this file does not provide any mutual
** exclusion and is thus suitable for use only in applications
** that use SQLite in a single thread.  But this implementation
** does do a lot of error checking on mutexes to make sure they
** are called correctly and at appropriate times.  Hence, this
** implementation is suitable for testing.
** debugging purposes
** This file contains code that is common across all mutex implementations.

**
** $Id: mutex.c,v 1.28 2008/09/01 18:34:20 danielk1977 Exp $
** $Id: mutex.c,v 1.29 2008/10/07 15:25:48 drh Exp $
*/

#ifndef SQLITE_MUTEX_NOOP
#ifndef SQLITE_MUTEX_OMIT
/*
** Initialize the mutex system.
*/
SQLITE_PRIVATE int sqlite3MutexInit(void){ 
  int rc = SQLITE_OK;
  if( sqlite3GlobalConfig.bCoreMutex ){
    if( !sqlite3GlobalConfig.mutex.xMutexAlloc ){

  return p==0 || sqlite3GlobalConfig.mutex.xMutexHeld(p);
}
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
  return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);
}
#endif

#endif
#endif /* SQLITE_OMIT_MUTEX */

/************** End of mutex.c ***********************************************/
/************** Begin file mutex_noop.c **************************************/
/*
** 2008 October 07
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes.
**
** This implementation in this file does not provide any mutual
** exclusion and is thus suitable for use only in applications
** that use SQLite in a single thread.  The routines defined
** here are place-holders.  Applications can substitute working
** mutex routines at start-time using the
**
**     sqlite3_config(SQLITE_CONFIG_MUTEX,...)
**
** interface.
**
** If compiled with SQLITE_DEBUG, then additional logic is inserted
** that does error checking on mutexes to make sure they are being
** called correctly.
**
** $Id: mutex_noop.c,v 1.2 2008/10/15 19:03:03 drh Exp $
*/


#ifdef SQLITE_MUTEX_NOOP_DEBUG
#if defined(SQLITE_MUTEX_NOOP) && !defined(SQLITE_DEBUG)
/*
** Stub routines for all mutex methods.
**
** This routines provide no mutual exclusion or error checking.
*/
static int noopMutexHeld(sqlite3_mutex *p){ return 1; }
static int noopMutexNotheld(sqlite3_mutex *p){ return 1; }
static int noopMutexInit(void){ return SQLITE_OK; }
static int noopMutexEnd(void){ return SQLITE_OK; }
static sqlite3_mutex *noopMutexAlloc(int id){ return (sqlite3_mutex*)8; }
static void noopMutexFree(sqlite3_mutex *p){ return; }
static void noopMutexEnter(sqlite3_mutex *p){ return; }
static int noopMutexTry(sqlite3_mutex *p){ return SQLITE_OK; }
static void noopMutexLeave(sqlite3_mutex *p){ return; }
** In this implementation, mutexes do not provide any mutual exclusion.
** But the error checking is provided.  This implementation is useful
** for test purposes.

SQLITE_PRIVATE sqlite3_mutex_methods *sqlite3DefaultMutex(void){
  static sqlite3_mutex_methods sMutex = {
    noopMutexInit,
    noopMutexEnd,
    noopMutexAlloc,
    noopMutexFree,
    noopMutexEnter,
    noopMutexTry,
    noopMutexLeave,

    noopMutexHeld,
    noopMutexNotheld
  };

  return &sMutex;
}
#endif /* defined(SQLITE_MUTEX_NOOP) && !defined(SQLITE_DEBUG) */

#if defined(SQLITE_MUTEX_NOOP) && defined(SQLITE_DEBUG)
/*
** In this implementation, error checking is provided for testing
** and debugging purposes.  The mutexes still do not provide any
** mutual exclusion.
*/

/*
** The mutex object
*/
struct sqlite3_mutex {
  int id;     /* The mutex type */
  int cnt;    /* Number of entries without a matching leave */
};

/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use inside assert() statements.
*/
static int noopMutexHeld(sqlite3_mutex *p){
static int debugMutexHeld(sqlite3_mutex *p){
  return p==0 || p->cnt>0;
}
static int noopMutexNotheld(sqlite3_mutex *p){
static int debugMutexNotheld(sqlite3_mutex *p){
  return p==0 || p->cnt==0;
}

/*
** Initialize and deinitialize the mutex subsystem.
*/
static int noopMutexInit(void){ return SQLITE_OK; }
static int noopMutexEnd(void){ return SQLITE_OK; }
static int debugMutexInit(void){ return SQLITE_OK; }
static int debugMutexEnd(void){ return SQLITE_OK; }

/*
** The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it.  If it returns NULL
** that means that a mutex could not be allocated. 
*/
static sqlite3_mutex *noopMutexAlloc(int id){
static sqlite3_mutex *debugMutexAlloc(int id){
  static sqlite3_mutex aStatic[6];
  sqlite3_mutex *pNew = 0;
  switch( id ){
    case SQLITE_MUTEX_FAST:
    case SQLITE_MUTEX_RECURSIVE: {
      pNew = sqlite3Malloc(sizeof(*pNew));
      if( pNew ){

  }
  return pNew;
}

/*
** This routine deallocates a previously allocated mutex.
*/
static void noopMutexFree(sqlite3_mutex *p){
static void debugMutexFree(sqlite3_mutex *p){
  assert( p->cnt==0 );
  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
  sqlite3_free(p);
}

/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread.  In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
static void noopMutexEnter(sqlite3_mutex *p){
  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
static void debugMutexEnter(sqlite3_mutex *p){
  assert( p->id==SQLITE_MUTEX_RECURSIVE || debugMutexNotheld(p) );
  p->cnt++;
}
static int noopMutexTry(sqlite3_mutex *p){
  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
static int debugMutexTry(sqlite3_mutex *p){
  assert( p->id==SQLITE_MUTEX_RECURSIVE || debugMutexNotheld(p) );
  p->cnt++;
  return SQLITE_OK;
}

/*
** The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  The behavior
** is undefined if the mutex is not currently entered or
** is not currently allocated.  SQLite will never do either.
*/
static void noopMutexLeave(sqlite3_mutex *p){
  assert( noopMutexHeld(p) );
static void debugMutexLeave(sqlite3_mutex *p){
  assert( debugMutexHeld(p) );
  p->cnt--;
  assert( p->id==SQLITE_MUTEX_RECURSIVE || noopMutexNotheld(p) );
  assert( p->id==SQLITE_MUTEX_RECURSIVE || debugMutexNotheld(p) );
}

SQLITE_PRIVATE sqlite3_mutex_methods *sqlite3DefaultMutex(void){
  static sqlite3_mutex_methods sMutex = {
    noopMutexInit,
    noopMutexEnd,
    noopMutexAlloc,
    noopMutexFree,
    noopMutexEnter,
    noopMutexTry,
    noopMutexLeave,
    debugMutexInit,
    debugMutexEnd,
    debugMutexAlloc,
    debugMutexFree,
    debugMutexEnter,
    debugMutexTry,
    debugMutexLeave,

    noopMutexHeld,
    noopMutexNotheld
    debugMutexHeld,
    debugMutexNotheld
  };

  return &sMutex;
}
#endif /* SQLITE_MUTEX_NOOP_DEBUG */
#endif /* defined(SQLITE_MUTEX_NOOP) && defined(SQLITE_DEBUG) */

/************** End of mutex.c ***********************************************/
/************** End of mutex_noop.c ******************************************/
/************** Begin file mutex_os2.c ***************************************/
/*
** 2007 August 28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement mutexes for win32
**
** $Id: mutex_w32.c,v 1.11 2008/06/26 10:41:19 danielk1977 Exp $
** $Id: mutex_w32.c,v 1.12 2008/11/10 20:01:41 shane Exp $
*/

/*
** The code in this file is only used if we are compiling multithreaded
** on a win32 system.
*/
#ifdef SQLITE_MUTEX_W32

**
** Here is an interesting observation:  Win95, Win98, and WinME lack
** the LockFileEx() API.  But we can still statically link against that
** API as long as we don't call it win running Win95/98/ME.  A call to
** this routine is used to determine if the host is Win95/98/ME or
** WinNT/2K/XP so that we will know whether or not we can safely call
** the LockFileEx() API.
**
** mutexIsNT() is only used for the TryEnterCriticalSection() API call,
** which is only available if your application was compiled with 
** _WIN32_WINNT defined to a value >= 0x0400.  Currently, the only
** call to TryEnterCriticalSection() is #ifdef'ed out, so #ifdef 
** this out as well.
*/
#if 0
#if SQLITE_OS_WINCE
# define mutexIsNT()  (1)
#else
  static int mutexIsNT(void){
    static int osType = 0;
    if( osType==0 ){
      OSVERSIONINFO sInfo;
      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
      GetVersionEx(&sInfo);
      osType = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return osType==2;
  }
#endif /* SQLITE_OS_WINCE */

#endif

#ifdef SQLITE_DEBUG
/*
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
** intended for use only inside assert() statements.
*/
static int winMutexHeld(sqlite3_mutex *p){

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Memory allocation functions used throughout sqlite.
**
** $Id: malloc.c,v 1.41 2008/09/04 04:32:49 shane Exp $
** $Id: malloc.c,v 1.45 2008/10/12 00:27:53 shane Exp $
*/

/*
** This routine runs when the memory allocator sees that the
** total memory allocation is about to exceed the soft heap
** limit.
*/

  mem0.alarmCallback = xCallback;
  mem0.alarmArg = pArg;
  mem0.alarmThreshold = iThreshold;
  sqlite3_mutex_leave(mem0.mutex);
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_DEPRECATED
/*
** Deprecated external interface.  Internal/core SQLite code
** should call sqlite3MemoryAlarm.
*/
SQLITE_API int sqlite3_memory_alarm(
  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
  void *pArg,
  sqlite3_int64 iThreshold
){
  return sqlite3MemoryAlarm(xCallback, pArg, iThreshold);
}
#endif

/*
** Trigger the alarm 
*/
static void sqlite3MallocAlarm(int nByte){
  void (*xCallback)(void*,sqlite3_int64,int);
  sqlite3_int64 nowUsed;

  }
}
#endif

/*
** TRUE if p is a lookaside memory allocation from db
*/
#ifndef SQLITE_OMIT_LOOKASIDE
static int isLookaside(sqlite3 *db, void *p){
  return db && p && p>=db->lookaside.pStart && p<db->lookaside.pEnd;
}
#else
#define isLookaside(A,B) 0
#endif

/*
** Return the size of a memory allocation previously obtained from
** sqlite3Malloc() or sqlite3_malloc().
*/
SQLITE_PRIVATE int sqlite3MallocSize(void *p){
  return sqlite3GlobalConfig.m.xSize(p);

  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
**
** If db!=0 and db->mallocFailed is true (indicating a prior malloc
** failure on the same database connection) then always return 0.
** Hence for a particular database connection, once malloc starts
** failing, it fails consistently until mallocFailed is reset.
** This is an important assumption.  There are many places in the
** code that do things like this:
**
**         int *a = (int*)sqlite3DbMallocRaw(db, 100);
**         int *b = (int*)sqlite3DbMallocRaw(db, 200);
**         if( b ) a[10] = 9;
**
** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
** that all prior mallocs (ex: "a") worked too.
*/
SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, int n){
  void *p;
#ifndef SQLITE_OMIT_LOOKASIDE
  if( db ){
    LookasideSlot *pBuf;
    if( db->mallocFailed ){
      return 0;
    }
    if( db->lookaside.bEnabled && n<=db->lookaside.sz
         && (pBuf = db->lookaside.pFree)!=0 ){
      db->lookaside.pFree = pBuf->pNext;
      db->lookaside.nOut++;
      if( db->lookaside.nOut>db->lookaside.mxOut ){
        db->lookaside.mxOut = db->lookaside.nOut;
      }
      return (void*)pBuf;
    }
  }
#else
  if( db && db->mallocFailed ){
    return 0;
  }
#endif
  p = sqlite3Malloc(n);
  if( !p && db ){
    db->mallocFailed = 1;
  }
  return p;
}

*/
SQLITE_PRIVATE int sqlite3ApiExit(sqlite3* db, int rc){
  /* If the db handle is not NULL, then we must hold the connection handle
  ** mutex here. Otherwise the read (and possible write) of db->mallocFailed 
  ** is unsafe, as is the call to sqlite3Error().
  */
  assert( !db || sqlite3_mutex_held(db->mutex) );
  if( db && db->mallocFailed ){
  if( db && (db->mallocFailed || rc==SQLITE_IOERR_NOMEM) ){
    sqlite3Error(db, SQLITE_NOMEM, 0);
    db->mallocFailed = 0;
    rc = SQLITE_NOMEM;
  }
  return rc & (db ? db->errMask : 0xff);
}

*************************************************************************
** This file contains code to implement a pseudo-random number
** generator (PRNG) for SQLite.
**
** Random numbers are used by some of the database backends in order
** to generate random integer keys for tables or random filenames.
**
** $Id: random.c,v 1.26 2008/09/02 00:52:52 drh Exp $
** $Id: random.c,v 1.27 2008/10/07 15:25:48 drh Exp $
*/


/* All threads share a single random number generator.
** This structure is the current state of the generator.
*/
static SQLITE_WSD struct sqlite3PrngType {

}

/*
** Return N random bytes.
*/
SQLITE_API void sqlite3_randomness(int N, void *pBuf){
  unsigned char *zBuf = pBuf;
#ifndef SQLITE_MUTEX_NOOP
#if SQLITE_THREADSAFE
  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);
#endif
  sqlite3_mutex_enter(mutex);
  while( N-- ){
    *(zBuf++) = randomByte();
  }
  sqlite3_mutex_leave(mutex);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used to translate between UTF-8, 
** UTF-16, UTF-16BE, and UTF-16LE.
**
** $Id: utf.c,v 1.65 2008/08/12 15:04:59 danielk1977 Exp $
** $Id: utf.c,v 1.66 2008/11/07 03:29:34 drh Exp $
**
** Notes on UTF-8:
**
**   Byte-0    Byte-1    Byte-2    Byte-3    Value
**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx

*************************************************************************
** This is the header file for information that is private to the
** VDBE.  This information used to all be at the top of the single
** source code file "vdbe.c".  When that file became too big (over
** 6000 lines long) it was split up into several smaller files and
** this header information was factored out.
**
** $Id: vdbeInt.h,v 1.154 2008/08/13 19:11:48 drh Exp $
** $Id: vdbeInt.h,v 1.157 2008/11/05 16:37:35 drh Exp $
*/
#ifndef _VDBEINT_H_
#define _VDBEINT_H_

/*
** intToKey() and keyToInt() used to transform the rowid.  But with
** the latest versions of the design they are no-ops.

** loop over all entries of the Btree.  You can also insert new BTree
** entries or retrieve the key or data from the entry that the cursor
** is currently pointing to.
** 
** Every cursor that the virtual machine has open is represented by an
** instance of the following structure.
**
** If the Cursor.isTriggerRow flag is set it means that this cursor is
** If the VdbeCursor.isTriggerRow flag is set it means that this cursor is
** really a single row that represents the NEW or OLD pseudo-table of
** a row trigger.  The data for the row is stored in Cursor.pData and
** the rowid is in Cursor.iKey.
** a row trigger.  The data for the row is stored in VdbeCursor.pData and
** the rowid is in VdbeCursor.iKey.
*/
struct Cursor {
struct VdbeCursor {
  BtCursor *pCursor;    /* The cursor structure of the backend */
  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
  i64 nextRowid;        /* Next rowid returned by OP_NewRowid */
  Bool zeroed;          /* True if zeroed out and ready for reuse */
  Bool rowidIsValid;    /* True if lastRowid is valid */
  Bool atFirst;         /* True if pointing to first entry */

  */
  int cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
  int payloadSize;      /* Total number of bytes in the record */
  u32 *aType;           /* Type values for all entries in the record */
  u32 *aOffset;         /* Cached offsets to the start of each columns data */
  u8 *aRow;             /* Data for the current row, if all on one page */
};
typedef struct Cursor Cursor;
typedef struct VdbeCursor VdbeCursor;

/*
** A value for Cursor.cacheValid that means the cache is always invalid.
** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/
#define CACHE_STALE 0

/*
** Internally, the vdbe manipulates nearly all SQL values as Mem
** structures. Each Mem struct may cache multiple representations (string,
** integer etc.) of the same value.  A value (and therefore Mem structure)

  Op *aOp;            /* Space to hold the virtual machine's program */
  int nLabel;         /* Number of labels used */
  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
  int *aLabel;        /* Space to hold the labels */
  Mem **apArg;        /* Arguments to currently executing user function */
  Mem *aColName;      /* Column names to return */
  int nCursor;        /* Number of slots in apCsr[] */
  Cursor **apCsr;     /* One element of this array for each open cursor */
  VdbeCursor **apCsr; /* One element of this array for each open cursor */
  int nVar;           /* Number of entries in aVar[] */
  Mem *aVar;          /* Values for the OP_Variable opcode. */
  char **azVar;       /* Name of variables */
  int okVar;          /* True if azVar[] has been initialized */
  int magic;              /* Magic number for sanity checking */
  int nMem;               /* Number of memory locations currently allocated */
  Mem *aMem;              /* The memory locations */
  int nCallback;          /* Number of callbacks invoked so far */
  int cacheCtr;           /* Cursor row cache generation counter */
  int cacheCtr;           /* VdbeCursor row cache generation counter */
  Fifo sFifo;             /* A list of ROWIDs */
  int contextStackTop;    /* Index of top element in the context stack */
  int contextStackDepth;  /* The size of the "context" stack */
  Context *contextStack;  /* Stack used by opcodes ContextPush & ContextPop*/
  int pc;                 /* The program counter */
  int rc;                 /* Value to return */
  unsigned uniqueCnt;     /* Used by OP_MakeRecord when P2!=0 */
  int errorAction;        /* Recovery action to do in case of an error */
  int inTempTrans;        /* True if temp database is transactioned */
  int nResColumn;         /* Number of columns in one row of the result set */
  char **azResColumn;     /* Values for one row of result */ 
  char *zErrMsg;          /* Error message written here */
  Mem *pResultSet;        /* Pointer to an array of results */
  u8 explain;             /* True if EXPLAIN present on SQL command */
  u8 changeCntOn;         /* True to update the change-counter */
  u8 expired;             /* True if the VM needs to be recompiled */
  u8 minWriteFileFormat;  /* Minimum file format for writable database files */
  u8 inVtabMethod;        /* See comments above */
  u8 usesStmtJournal;     /* True if uses a statement journal */
  u8 readOnly;            /* True for read-only statements */
  int nChange;            /* Number of db changes made since last reset */
  i64 startTime;          /* Time when query started - used for profiling */
  int btreeMask;          /* Bitmask of db->aDb[] entries referenced */
  BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */
  int aCounter[2];        /* Counters used by sqlite3_stmt_status() */
  int nSql;             /* Number of bytes in zSql */
  char *zSql;           /* Text of the SQL statement that generated this */
#ifdef SQLITE_DEBUG
  FILE *trace;        /* Write an execution trace here, if not NULL */
  FILE *trace;          /* Write an execution trace here, if not NULL */
#endif
  int openedStatement;  /* True if this VM has opened a statement journal */
#ifdef SQLITE_SSE
  int fetchId;          /* Statement number used by sqlite3_fetch_statement */
  int lru;              /* Counter used for LRU cache replacement */
#endif
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
#define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
#define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */

/*
** Function prototypes
*/
SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *, Cursor*);
SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
void sqliteVdbePopStack(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(Cursor*);
SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor*);
#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE*, int, Op*);
#endif
SQLITE_PRIVATE int sqlite3VdbeSerialTypeLen(u32);
SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int);
SQLITE_PRIVATE int sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
SQLITE_PRIVATE int sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);

int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(Cursor*,UnpackedRecord*,int*);
SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*);
SQLITE_PRIVATE int sqlite3VdbeIdxRowid(BtCursor *, i64 *);
SQLITE_PRIVATE int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
SQLITE_PRIVATE int sqlite3VdbeExec(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeList(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *, int);
SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem*);

    int rc;
    rc = sqlite3VdbeMemMakeWriteable(pMem);
    if( rc!=SQLITE_OK ){
      assert( rc==SQLITE_NOMEM );
      return SQLITE_NOMEM;
    }
    zIn = (u8*)pMem->z;
    zTerm = &zIn[pMem->n];
    zTerm = &zIn[pMem->n&~1];
    while( zIn<zTerm ){
      temp = *zIn;
      *zIn = *(zIn+1);
      zIn++;
      *zIn++ = temp;
    }
    pMem->enc = desiredEnc;
    goto translate_out;
  }

  /* Set len to the maximum number of bytes required in the output buffer. */
  if( desiredEnc==SQLITE_UTF8 ){
    /* When converting from UTF-16, the maximum growth results from
    ** translating a 2-byte character to a 4-byte UTF-8 character.
    ** A single byte is required for the output string
    ** nul-terminator.
    */
    pMem->n &= ~1;
    len = pMem->n * 2 + 1;
  }else{
    /* When converting from UTF-8 to UTF-16 the maximum growth is caused
    ** when a 1-byte UTF-8 character is translated into a 2-byte UTF-16
    ** character. Two bytes are required in the output buffer for the
    ** nul-terminator.
    */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the implementation of generic hash-tables
** used in SQLite.
**
** $Id: hash.c,v 1.30 2008/06/20 14:59:51 danielk1977 Exp $
** $Id: hash.c,v 1.31 2008/10/10 17:41:29 drh Exp $
*/

/* Turn bulk memory into a hash table object by initializing the
** fields of the Hash structure.
**
** "pNew" is a pointer to the hash table that is to be initialized.
** keyClass is one of the constants SQLITE_HASH_INT, SQLITE_HASH_POINTER,
** SQLITE_HASH_BINARY, or SQLITE_HASH_STRING.  The value of keyClass 
** determines what kind of key the hash table will use.  "copyKey" is
** true if the hash table should make its own private copy of keys and
** false if it should just use the supplied pointer.  CopyKey only makes
** "copyKey" is true if the hash table should make its own private
** copy of keys and false if it should just use the supplied pointer.
** sense for SQLITE_HASH_STRING and SQLITE_HASH_BINARY and is ignored
** for other key classes.
*/
SQLITE_PRIVATE void sqlite3HashInit(Hash *pNew, int keyClass, int copyKey){
SQLITE_PRIVATE void sqlite3HashInit(Hash *pNew, int copyKey){
  assert( pNew!=0 );
  assert( keyClass>=SQLITE_HASH_STRING && keyClass<=SQLITE_HASH_BINARY );
  pNew->keyClass = keyClass;
#if 0
  if( keyClass==SQLITE_HASH_POINTER || keyClass==SQLITE_HASH_INT ) copyKey = 0;
#endif
  pNew->copyKey = copyKey;
  pNew->copyKey = copyKey!=0;
  pNew->first = 0;
  pNew->count = 0;
  pNew->htsize = 0;
  pNew->ht = 0;
}

/* Remove all entries from a hash table.  Reclaim all memory.

    }
    sqlite3_free(elem);
    elem = next_elem;
  }
  pH->count = 0;
}

#if 0 /* NOT USED */
/*
** Hash and comparison functions when the mode is SQLITE_HASH_INT
*/
static int intHash(const void *pKey, int nKey){
  return nKey ^ (nKey<<8) ^ (nKey>>8);
}
static int intCompare(const void *pKey1, int n1, const void *pKey2, int n2){
  return n2 - n1;
}
#endif

#if 0 /* NOT USED */
/*
** Hash and comparison functions when the mode is SQLITE_HASH_POINTER
*/
static int ptrHash(const void *pKey, int nKey){
  uptr x = Addr(pKey);
  return x ^ (x<<8) ^ (x>>8);
}
static int ptrCompare(const void *pKey1, int n1, const void *pKey2, int n2){
  if( pKey1==pKey2 ) return 0;
  if( pKey1<pKey2 ) return -1;
  return 1;
}
#endif

/*
** Hash and comparison functions when the mode is SQLITE_HASH_STRING
*/
static int strHash(const void *pKey, int nKey){
  const char *z = (const char *)pKey;
  int h = 0;
  if( nKey<=0 ) nKey = strlen(z);
  while( nKey > 0  ){
    h = (h<<3) ^ h ^ sqlite3UpperToLower[(unsigned char)*z++];
    nKey--;
  }
  return h & 0x7fffffff;
}
static int strCompare(const void *pKey1, int n1, const void *pKey2, int n2){
  if( n1!=n2 ) return 1;
  return sqlite3StrNICmp((const char*)pKey1,(const char*)pKey2,n1);
}

/*
** Hash and comparison functions when the mode is SQLITE_HASH_BINARY
*/
static int binHash(const void *pKey, int nKey){
  int h = 0;
  const char *z = (const char *)pKey;
  while( nKey-- > 0 ){
    h = (h<<3) ^ h ^ *(z++);
  }
  return h & 0x7fffffff;
}
static int binCompare(const void *pKey1, int n1, const void *pKey2, int n2){
  if( n1!=n2 ) return 1;
  return memcmp(pKey1,pKey2,n1);
}

/*
** Return a pointer to the appropriate hash function given the key class.
**
** The C syntax in this function definition may be unfamilar to some 
** programmers, so we provide the following additional explanation:
**
** The name of the function is "hashFunction".  The function takes a
** single parameter "keyClass".  The return value of hashFunction()
** is a pointer to another function.  Specifically, the return value
** of hashFunction() is a pointer to a function that takes two parameters
** with types "const void*" and "int" and returns an "int".
*/
static int (*hashFunction(int keyClass))(const void*,int){
#if 0  /* HASH_INT and HASH_POINTER are never used */
  switch( keyClass ){
    case SQLITE_HASH_INT:     return &intHash;
    case SQLITE_HASH_POINTER: return &ptrHash;
    case SQLITE_HASH_STRING:  return &strHash;
    case SQLITE_HASH_BINARY:  return &binHash;;
    default: break;
  }
  return 0;
#else
  if( keyClass==SQLITE_HASH_STRING ){
    return &strHash;
  }else{
    assert( keyClass==SQLITE_HASH_BINARY );
    return &binHash;
  }
#endif
}

/*
** Return a pointer to the appropriate hash function given the key class.
**
** For help in interpreted the obscure C code in the function definition,
** see the header comment on the previous function.
*/
static int (*compareFunction(int keyClass))(const void*,int,const void*,int){
#if 0 /* HASH_INT and HASH_POINTER are never used */
  switch( keyClass ){
    case SQLITE_HASH_INT:     return &intCompare;
    case SQLITE_HASH_POINTER: return &ptrCompare;
    case SQLITE_HASH_STRING:  return &strCompare;
    case SQLITE_HASH_BINARY:  return &binCompare;
    default: break;
  }
  return 0;
#else
  if( keyClass==SQLITE_HASH_STRING ){
    return &strCompare;
  }else{
    assert( keyClass==SQLITE_HASH_BINARY );
    return &binCompare;
  }
#endif
}

/* Link an element into the hash table
*/
static void insertElement(
  Hash *pH,              /* The complete hash table */
  struct _ht *pEntry,    /* The entry into which pNew is inserted */
  HashElem *pNew         /* The element to be inserted */

/* Resize the hash table so that it cantains "new_size" buckets.
** "new_size" must be a power of 2.  The hash table might fail 
** to resize if sqlite3_malloc() fails.
*/
static void rehash(Hash *pH, int new_size){
  struct _ht *new_ht;            /* The new hash table */
  HashElem *elem, *next_elem;    /* For looping over existing elements */
  int (*xHash)(const void*,int); /* The hash function */

#ifdef SQLITE_MALLOC_SOFT_LIMIT
  if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){
    new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);
  }
  if( new_size==pH->htsize ) return;
#endif

  new_ht = (struct _ht *)sqlite3MallocZero( new_size*sizeof(struct _ht) );
  if( pH->htsize>0 ) sqlite3EndBenignMalloc();

  if( new_ht==0 ) return;
  sqlite3_free(pH->ht);
  pH->ht = new_ht;
  pH->htsize = new_size;
  xHash = hashFunction(pH->keyClass);
  for(elem=pH->first, pH->first=0; elem; elem = next_elem){
    int h = (*xHash)(elem->pKey, elem->nKey) & (new_size-1);
    int h = strHash(elem->pKey, elem->nKey) & (new_size-1);
    next_elem = elem->next;
    insertElement(pH, &new_ht[h], elem);
  }
}

/* This function (for internal use only) locates an element in an
** hash table that matches the given key.  The hash for this key has
** already been computed and is passed as the 4th parameter.
*/
static HashElem *findElementGivenHash(
  const Hash *pH,     /* The pH to be searched */
  const void *pKey,   /* The key we are searching for */
  int nKey,
  int h               /* The hash for this key. */
){
  HashElem *elem;                /* Used to loop thru the element list */
  int count;                     /* Number of elements left to test */
  int (*xCompare)(const void*,int,const void*,int);  /* comparison function */

  if( pH->ht ){
    struct _ht *pEntry = &pH->ht[h];
    elem = pEntry->chain;
    count = pEntry->count;
    xCompare = compareFunction(pH->keyClass);
    while( count-- && elem ){
      if( (*xCompare)(elem->pKey,elem->nKey,pKey,nKey)==0 ){ 
      if( strCompare(elem->pKey,elem->nKey,pKey,nKey)==0 ){ 
        return elem;
      }
      elem = elem->next;
    }
  }
  return 0;
}

** that matches pKey,nKey.  Return a pointer to the corresponding 
** HashElem structure for this element if it is found, or NULL
** otherwise.
*/
SQLITE_PRIVATE HashElem *sqlite3HashFindElem(const Hash *pH, const void *pKey, int nKey){
  int h;             /* A hash on key */
  HashElem *elem;    /* The element that matches key */
  int (*xHash)(const void*,int);  /* The hash function */

  if( pH==0 || pH->ht==0 ) return 0;
  xHash = hashFunction(pH->keyClass);
  assert( xHash!=0 );
  h = (*xHash)(pKey,nKey);
  h = strHash(pKey,nKey);
  elem = findElementGivenHash(pH,pKey,nKey, h % pH->htsize);
  return elem;
}

/* Attempt to locate an element of the hash table pH with a key
** that matches pKey,nKey.  Return the data for this element if it is
** found, or NULL if there is no match.

** element corresponding to "key" is removed from the hash table.
*/
SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const void *pKey, int nKey, void *data){
  int hraw;             /* Raw hash value of the key */
  int h;                /* the hash of the key modulo hash table size */
  HashElem *elem;       /* Used to loop thru the element list */
  HashElem *new_elem;   /* New element added to the pH */
  int (*xHash)(const void*,int);  /* The hash function */

  assert( pH!=0 );
  xHash = hashFunction(pH->keyClass);
  assert( xHash!=0 );
  hraw = (*xHash)(pKey, nKey);
  hraw = strHash(pKey, nKey);
  if( pH->htsize ){
    h = hraw % pH->htsize;
    elem = findElementGivenHash(pH,pKey,nKey,h);
    if( elem ){
      void *old_data = elem->data;
      if( data==0 ){
        removeElementGivenHash(pH,elem,h);

     /* 118 */ "Blob",
     /* 119 */ "Rewind",
     /* 120 */ "MoveGe",
     /* 121 */ "VBegin",
     /* 122 */ "VUpdate",
     /* 123 */ "IfZero",
     /* 124 */ "VCreate",
     /* 125 */ "Real",
     /* 126 */ "Found",
     /* 125 */ "Found",
     /* 126 */ "Real",
     /* 127 */ "IfPos",
     /* 128 */ "NullRow",
     /* 129 */ "Jump",
     /* 130 */ "Permutation",
     /* 131 */ "NotUsed_131",
     /* 132 */ "NotUsed_132",
     /* 133 */ "NotUsed_133",
     /* 134 */ "NotUsed_134",
     /* 135 */ "NotUsed_135",
     /* 136 */ "NotUsed_136",
     /* 137 */ "NotUsed_137",
     /* 138 */ "ToText",
     /* 139 */ "ToBlob",
     /* 140 */ "ToNumeric",
     /* 141 */ "ToInt",
     /* 142 */ "ToReal",
     /* 138 */ "NotUsed_138",
     /* 139 */ "ToText",
     /* 140 */ "ToBlob",
     /* 141 */ "ToNumeric",
     /* 142 */ "ToInt",
     /* 143 */ "ToReal",
  };
  return azName[i];
}
#endif

/************** End of opcodes.c *********************************************/
/************** Begin file os_os2.c ******************************************/

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code that is specific to OS/2.
**
** $Id: os_os2.c,v 1.56 2008/08/22 13:47:57 pweilbacher Exp $
** $Id: os_os2.c,v 1.58 2008/11/07 00:06:18 drh Exp $
*/


#if SQLITE_OS_OS2

/*
** A Note About Memory Allocation:

  }
  if( DosRead( pFile->h, pBuf, amt, &got ) != NO_ERROR ){
    return SQLITE_IOERR_READ;
  }
  if( got == (ULONG)amt )
    return SQLITE_OK;
  else {
    /* Unread portions of the input buffer must be zero-filled */
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

/*
** Write data from a buffer into a file.  Return SQLITE_OK on success

*/
static int os2Truncate( sqlite3_file *id, i64 nByte ){
  APIRET rc = NO_ERROR;
  os2File *pFile = (os2File*)id;
  OSTRACE3( "TRUNCATE %d %lld\n", pFile->h, nByte );
  SimulateIOError( return SQLITE_IOERR_TRUNCATE );
  rc = DosSetFileSize( pFile->h, nByte );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR_TRUNCATE;
}

#ifdef SQLITE_TEST
/*
** Count the number of fullsyncs and normal syncs.  This is used to test
** that syncs and fullsyncs are occuring at the right times.
*/

** Determine the current size of a file in bytes
*/
static int os2FileSize( sqlite3_file *id, sqlite3_int64 *pSize ){
  APIRET rc = NO_ERROR;
  FILESTATUS3 fsts3FileInfo;
  memset(&fsts3FileInfo, 0, sizeof(fsts3FileInfo));
  assert( id!=0 );
  SimulateIOError( return SQLITE_IOERR );
  SimulateIOError( return SQLITE_IOERR_FSTAT );
  rc = DosQueryFileInfo( ((os2File*)id)->h, FIL_STANDARD, &fsts3FileInfo, sizeof(FILESTATUS3) );
  if( rc == NO_ERROR ){
    *pSize = fsts3FileInfo.cbFile;
    return SQLITE_OK;
  }else{
    return SQLITE_IOERR;
    return SQLITE_IOERR_FSTAT;
  }
}

/*
** Acquire a reader lock.
*/
static int getReadLock( os2File *pFile ){

){
  APIRET rc = NO_ERROR;
  char *zFilenameCp = convertUtf8PathToCp( zFilename );
  SimulateIOError( return SQLITE_IOERR_DELETE );
  rc = DosDelete( (PSZ)zFilenameCp );
  free( zFilenameCp );
  OSTRACE2( "DELETE \"%s\"\n", zFilename );
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR_DELETE;
}

/*
** Check the existance and status of a file.
*/
static int os2Access(
  sqlite3_vfs *pVfs,        /* Not used on os2 */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code that is specific to Unix systems.
**
** $Id: os_unix.c,v 1.201 2008/09/15 04:20:32 danielk1977 Exp $
** $Id: os_unix.c,v 1.209 2008/11/11 18:34:35 danielk1977 Exp $
*/
#if SQLITE_OS_UNIX              /* This file is used on unix only */

/*
** If SQLITE_ENABLE_LOCKING_STYLE is defined, then several different 
** locking implementations are provided:
** If SQLITE_ENABLE_LOCKING_STYLE is defined and is non-zero, then several
** alternative locking implementations are provided:
**
**   * POSIX locking (the default),
**   * No locking,
**   * Dot-file locking,
**   * flock() locking,
**   * AFP locking (OSX only).
**
** SQLITE_ENABLE_LOCKING_STYLE only works on a Mac. It is turned on by
** default on a Mac and disabled on all other posix platforms.
*/
#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
#  if defined(__DARWIN__)
#    define SQLITE_ENABLE_LOCKING_STYLE 1
#  else
/* #define SQLITE_ENABLE_LOCKING_STYLE 0 */
#    define SQLITE_ENABLE_LOCKING_STYLE 0
#  endif
#endif

/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks
** large file support, these should be no-ops.
**
** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/time.h>
#include <errno.h>

#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/mount.h>
#endif /* SQLITE_ENABLE_LOCKING_STYLE */

/*
** If we are to be thread-safe, include the pthreads header and define

  /* In test mode, increase the size of this structure a bit so that 
  ** it is larger than the struct CrashFile defined in test6.c.
  */
  char aPadding[32];
#endif
  struct openCnt *pOpen;    /* Info about all open fd's on this inode */
  struct lockInfo *pLock;   /* Info about locks on this inode */
#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
  void *lockingContext;     /* Locking style specific state */
#endif
  int h;                    /* The file descriptor */
  unsigned char locktype;   /* The type of lock held on this fd */
  int dirfd;                /* File descriptor for the directory */
#if SQLITE_THREADSAFE
  pthread_t tid;            /* The thread that "owns" this unixFile */

** a normal expected return code of SQLITE_BUSY or SQLITE_OK
*/
#define IS_LOCK_ERROR(x)  ((x != SQLITE_OK) && (x != SQLITE_BUSY))

/*
** Helper functions to obtain and relinquish the global mutex.
*/
static void enterMutex(){
static void enterMutex(void){
  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
}
static void leaveMutex(){
static void leaveMutex(void){
  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
}

#if SQLITE_THREADSAFE
/*
** This variable records whether or not threads can override each others
** locks.

  }
  errno = savedErrno;
  return s;
}
#define fcntl lockTrace
#endif /* SQLITE_LOCK_TRACE */

#ifdef __linux__
/*
** This function is used as the main routine for a thread launched by
** The testThreadLockingBehavior() routine launches two separate
** testThreadLockingBehavior(). It tests whether the shared-lock obtained
** threads on this routine.  This routine attempts to lock a file
** descriptor then returns.  The success or failure of that attempt
** allows the testThreadLockingBehavior() procedure to determine
** whether or not threads can override each others locks.
*/
** by the main thread in testThreadLockingBehavior() conflicts with a
** hypothetical write-lock obtained by this thread on the same file.
**
** The write-lock is not actually acquired, as this is not possible if 
** the file is open in read-only mode (see ticket #3472).
*/ 
static void *threadLockingTest(void *pArg){
  struct threadTestData *pData = (struct threadTestData*)pArg;
  pData->result = fcntl(pData->fd, F_SETLK, &pData->lock);
  pData->result = fcntl(pData->fd, F_GETLK, &pData->lock);
  return pArg;
}

/*
** This procedure attempts to determine whether or not threads
** can override each others locks then sets the 
** threadsOverrideEachOthersLocks variable appropriately.
*/
static void testThreadLockingBehavior(int fd_orig){
  int fd;
  int rc;
  struct threadTestData d[2];
  pthread_t t[2];
  struct threadTestData d;
  struct flock l;
  pthread_t t;

  fd = dup(fd_orig);
  if( fd<0 ) return;
  memset(d, 0, sizeof(d));
  memset(&l, 0, sizeof(l));
  d[0].fd = fd;
  d[0].lock.l_type = F_RDLCK;
  d[0].lock.l_len = 1;
  d[0].lock.l_start = 0;
  d[0].lock.l_whence = SEEK_SET;
  d[1] = d[0];
  d[1].lock.l_type = F_WRLCK;
  pthread_create(&t[0], 0, threadLockingTest, &d[0]);
  l.l_type = F_RDLCK;
  l.l_len = 1;
  l.l_start = 0;
  l.l_whence = SEEK_SET;
  rc = fcntl(fd_orig, F_SETLK, &l);
  if( rc!=0 ) return;
  memset(&d, 0, sizeof(d));
  d.fd = fd;
  d.lock = l;
  d.lock.l_type = F_WRLCK;
  pthread_create(&t, 0, threadLockingTest, &d);
  pthread_create(&t[1], 0, threadLockingTest, &d[1]);
  pthread_join(t[0], 0);
  pthread_join(t, 0);
  pthread_join(t[1], 0);
  close(fd);
  if( d.result!=0 ) return;
  threadsOverrideEachOthersLocks = (d.lock.l_type==F_UNLCK);
}
#else
/*
** On anything other than linux, assume threads override each others locks.
*/
static void testThreadLockingBehavior(int fd_orig){
  threadsOverrideEachOthersLocks =  d[0].result==0 && d[1].result==0;
  threadsOverrideEachOthersLocks = 1;
}
#endif /* __linux__ */

#endif /* SQLITE_THREADSAFE */

/*
** Release a lockInfo structure previously allocated by findLockInfo().
*/
static void releaseLockInfo(struct lockInfo *pLock){
  if( pLock ){

      }
      sqlite3_free(pOpen->aPending);
      sqlite3_free(pOpen);
    }
  }
}

#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
/*
** Tests a byte-range locking query to see if byte range locks are 
** supported, if not we fall back to dotlockLockingStyle.
*/
static int testLockingStyle(int fd){
  struct flock lockInfo;

** returns LOCKING_STYLE_POSIX.
*/
static int detectLockingStyle(
  sqlite3_vfs *pVfs,
  const char *filePath, 
  int fd
){
#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
  struct Mapping {
    const char *zFilesystem;
    int eLockingStyle;
  } aMap[] = {
    { "hfs",    LOCKING_STYLE_POSIX },
    { "ufs",    LOCKING_STYLE_POSIX },
    { "afpfs",  LOCKING_STYLE_AFP },

  assert( id );
  got = seekAndRead((unixFile*)id, offset, pBuf, amt);
  if( got==amt ){
    return SQLITE_OK;
  }else if( got<0 ){
    return SQLITE_IOERR_READ;
  }else{
    /* Unread parts of the buffer must be zero-filled */
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

/*
** Seek to the offset in id->offset then read cnt bytes into pBuf.

  int isDataOnly = (flags&SQLITE_SYNC_DATAONLY);
  int isFullsync = (flags&0x0F)==SQLITE_SYNC_FULL;

  /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
  assert((flags&0x0F)==SQLITE_SYNC_NORMAL
      || (flags&0x0F)==SQLITE_SYNC_FULL
  );

  /* Unix cannot, but some systems may return SQLITE_FULL from here. This
  ** line is to test that doing so does not cause any problems.
  */
  SimulateDiskfullError( return SQLITE_FULL );

  assert( pFile );
  OSTRACE2("SYNC    %-3d\n", pFile->h);
  rc = full_fsync(pFile->h, isFullsync, isDataOnly);
  SimulateIOError( rc=1 );
  if( rc ){
    return SQLITE_IOERR_FSYNC;

    closeUnixFile(id);
    leaveMutex();
  }
  return SQLITE_OK;
}


#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
#pragma mark AFP Support

/*
 ** The afpLockingContext structure contains all afp lock specific state
 */
typedef struct afpLockingContext afpLockingContext;
struct afpLockingContext {

    unixFileControl,            /* xFileControl */                       \
    unixSectorSize,             /* xSectorSize */                        \
    unixDeviceCharacteristics   /* xDeviceCapabilities */                \
  }
  static sqlite3_io_methods aIoMethod[] = {
    IOMETHODS(unixClose, unixLock, unixUnlock, unixCheckReservedLock) 
   ,IOMETHODS(nolockClose, nolockLock, nolockUnlock, nolockCheckReservedLock)
#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
   ,IOMETHODS(dotlockClose, dotlockLock, dotlockUnlock,dotlockCheckReservedLock)
   ,IOMETHODS(flockClose, flockLock, flockUnlock, flockCheckReservedLock)
   ,IOMETHODS(afpClose, afpLock, afpUnlock, afpCheckReservedLock)
#endif
  };
  /* The order of the IOMETHODS macros above is important.  It must be the
  ** same order as the LOCKING_STYLE numbers

    case LOCKING_STYLE_POSIX: {
      enterMutex();
      rc = findLockInfo(h, &pNew->pLock, &pNew->pOpen);
      leaveMutex();
      break;
    }

#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
    case LOCKING_STYLE_AFP: {
      /* AFP locking uses the file path so it needs to be included in
      ** the afpLockingContext.
      */
      afpLockingContext *pCtx;
      pNew->lockingContext = pCtx = sqlite3_malloc( sizeof(*pCtx) );
      if( pCtx==0 ){

** Delete the file at zPath. If the dirSync argument is true, fsync()
** the directory after deleting the file.
*/
static int unixDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  int rc = SQLITE_OK;
  SimulateIOError(return SQLITE_IOERR_DELETE);
  unlink(zPath);
#ifndef SQLITE_DISABLE_DIRSYNC
  if( dirSync ){
    int fd;
    rc = openDirectory(zPath, &fd);
    if( rc==SQLITE_OK ){
      if( fsync(fd) ){
        rc = SQLITE_IOERR_DIR_FSYNC;
      }
      close(fd);
    }
  }
#endif
  return rc;
}

/*
** Test the existance of or access permissions of file zPath. The
** test performed depends on the value of flags:
**

    fd = open("/dev/urandom", O_RDONLY);
    if( fd<0 ){
      time_t t;
      time(&t);
      memcpy(zBuf, &t, sizeof(t));
      pid = getpid();
      memcpy(&zBuf[sizeof(t)], &pid, sizeof(pid));
      assert( sizeof(t)+sizeof(pid)<=nBuf );
      nBuf = sizeof(t) + sizeof(pid);
    }else{
      read(fd, zBuf, nBuf);
      nBuf = read(fd, zBuf, nBuf);
      close(fd);
    }
  }
#endif
  return SQLITE_OK;
  return nBuf;
}


/*
** Sleep for a little while.  Return the amount of time slept.
** The argument is the number of microseconds we want to sleep.
** The return value is the number of microseconds of sleep actually

    unixRandomness,       /* xRandomness */                 \
    unixSleep,            /* xSleep */                      \
    unixCurrentTime,      /* xCurrentTime */                \
    unixGetLastError      /* xGetLastError */               \
  }

  static sqlite3_vfs unixVfs = UNIXVFS("unix", 0);
#ifdef SQLITE_ENABLE_LOCKING_STYLE
#if SQLITE_ENABLE_LOCKING_STYLE
  int i;
  static sqlite3_vfs aVfs[] = {
    UNIXVFS("unix-posix",   LOCKING_STYLE_POSIX), 
    UNIXVFS("unix-afp",     LOCKING_STYLE_AFP), 
    UNIXVFS("unix-flock",   LOCKING_STYLE_FLOCK), 
    UNIXVFS("unix-dotfile", LOCKING_STYLE_DOTFILE), 
    UNIXVFS("unix-none",    LOCKING_STYLE_NONE)

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code that is specific to windows.
**
** $Id: os_win.c,v 1.133 2008/09/01 22:15:19 shane Exp $
** $Id: os_win.c,v 1.137 2008/11/07 00:06:18 drh Exp $
*/
#if SQLITE_OS_WIN               /* This file is used for windows only */


/*
** A Note About Memory Allocation:
**

# define INVALID_FILE_ATTRIBUTES ((DWORD)-1) 
#endif

/*
** Determine if we are dealing with WindowsCE - which has a much
** reduced API.
*/
#if defined(SQLITE_OS_WINCE)
#if SQLITE_OS_WINCE
# define AreFileApisANSI() 1
#endif

/*
** WinCE lacks native support for file locking so we have to fake it
** with some code of our own.
*/

#define MX_CLOSE_ATTEMPT 3
static int winClose(sqlite3_file *id){
  int rc, cnt = 0;
  winFile *pFile = (winFile*)id;
  OSTRACE2("CLOSE %d\n", pFile->h);
  do{
    rc = CloseHandle(pFile->h);
  }while( rc==0 && cnt++ < MX_CLOSE_ATTEMPT && (Sleep(100), 1) );
  }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (Sleep(100), 1) );
#if SQLITE_OS_WINCE
#define WINCE_DELETION_ATTEMPTS 3
  winceDestroyLock(pFile);
  if( pFile->zDeleteOnClose ){
    int cnt = 0;
    while(
           DeleteFileW(pFile->zDeleteOnClose)==0

  }
  if( !ReadFile(pFile->h, pBuf, amt, &got, 0) ){
    return SQLITE_IOERR_READ;
  }
  if( got==(DWORD)amt ){
    return SQLITE_OK;
  }else{
    /* Unread parts of the buffer must be zero-filled */
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

/*
** Write data from a buffer into a file.  Return SQLITE_OK on success

  return SQLITE_OK;
}

/*
** Truncate an open file to a specified size
*/
static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
  DWORD rc;
  LONG upperBits = (nByte>>32) & 0x7fffffff;
  LONG lowerBits = nByte & 0xffffffff;
  winFile *pFile = (winFile*)id;
  OSTRACE3("TRUNCATE %d %lld\n", pFile->h, nByte);
  SimulateIOError(return SQLITE_IOERR_TRUNCATE);
  SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
  SetEndOfFile(pFile->h);
  return SQLITE_OK;
  rc = SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
  if( INVALID_SET_FILE_POINTER != rc ){
    /* SetEndOfFile will fail if nByte is negative */
    if( SetEndOfFile(pFile->h) ){
      return SQLITE_OK;
    }
  }
  return SQLITE_IOERR_TRUNCATE;
}

#ifdef SQLITE_TEST
/*
** Count the number of fullsyncs and normal syncs.  This is used to test
** that syncs and fullsyncs are occuring at the right times.
*/

  if( isNT() ){
    OVERLAPPED ovlp;
    ovlp.Offset = SHARED_FIRST;
    ovlp.OffsetHigh = 0;
    ovlp.hEvent = 0;
    res = LockFileEx(pFile->h, LOCKFILE_FAIL_IMMEDIATELY,
                     0, SHARED_SIZE, 0, &ovlp);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
*/
#if SQLITE_OS_WINCE==0
  }else{
    int lk;
    sqlite3_randomness(sizeof(lk), &lk);
    pFile->sharedLockByte = (lk & 0x7fffffff)%(SHARED_SIZE - 1);
    res = LockFile(pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
#endif
  }
  return res;
}

/*
** Undo a readlock
*/
static int unlockReadLock(winFile *pFile){
  int res;
  if( isNT() ){
    res = UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
*/
#if SQLITE_OS_WINCE==0
  }else{
    res = UnlockFile(pFile->h, SHARED_FIRST + pFile->sharedLockByte, 0, 1, 0);
#endif
  }
  return res;
}

/*
** Lock the file with the lock specified by parameter locktype - one
** of the following:

** is obtained from malloc and must be freed by the calling
** function.
*/
static void *convertUtf8Filename(const char *zFilename){
  void *zConverted = 0;
  if( isNT() ){
    zConverted = utf8ToUnicode(zFilename);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
*/
#if SQLITE_OS_WINCE==0
  }else{
    zConverted = utf8ToMbcs(zFilename);
#endif
  }
  /* caller will handle out of memory */
  return zConverted;
}

/*
** Create a temporary file name in zBuf.  zBuf must be big enough to

    zMulti = unicodeToUtf8(zWidePath);
    if( zMulti ){
      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zMulti);
      free(zMulti);
    }else{
      return SQLITE_NOMEM;
    }
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    char *zUtf8;
    char zMbcsPath[MAX_PATH];
    GetTempPathA(MAX_PATH-30, zMbcsPath);
    zUtf8 = mbcsToUtf8(zMbcsPath);
    if( zUtf8 ){
      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zUtf8);
      free(zUtf8);
    }else{
      return SQLITE_NOMEM;
    }
#endif
  }
  for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
  zTempPath[i] = 0;
  sqlite3_snprintf(nBuf-30, zBuf,
                   "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath);
  j = strlen(zBuf);
  sqlite3_randomness(20, &zBuf[j]);

  int *pOutFlags            /* Status return flags */
){
  HANDLE h;
  DWORD dwDesiredAccess;
  DWORD dwShareMode;
  DWORD dwCreationDisposition;
  DWORD dwFlagsAndAttributes = 0;
#if SQLITE_OS_WINCE
  int isTemp;
  int isTemp = 0;
#endif
  winFile *pFile = (winFile*)id;
  void *zConverted;                 /* Filename in OS encoding */
  const char *zUtf8Name = zName;    /* Filename in UTF-8 encoding */
  char zTmpname[MAX_PATH+1];        /* Buffer used to create temp filename */

  /* If the second argument to this function is NULL, generate a 
  ** temporary file name to use 

    dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
  }else{
    dwShareMode = 0;
  }
  if( flags & SQLITE_OPEN_DELETEONCLOSE ){
#if SQLITE_OS_WINCE
    dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;
    isTemp = 1;
#else
    dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY
                               | FILE_ATTRIBUTE_HIDDEN
                               | FILE_FLAG_DELETE_ON_CLOSE;
#endif
    isTemp = 1;
  }else{
    dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
    isTemp = 0;
  }
  /* Reports from the internet are that performance is always
  ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
#if SQLITE_OS_WINCE
  dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
#endif
  if( isNT() ){
    h = CreateFileW((WCHAR*)zConverted,
       dwDesiredAccess,
       dwShareMode,
       NULL,
       dwCreationDisposition,
       dwFlagsAndAttributes,
       NULL
    );
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    h = CreateFileA((char*)zConverted,
       dwDesiredAccess,
       dwShareMode,
       NULL,
       dwCreationDisposition,
       dwFlagsAndAttributes,
       NULL
    );
#endif
  }
  if( h==INVALID_HANDLE_VALUE ){
    free(zConverted);
    if( flags & SQLITE_OPEN_READWRITE ){
      return winOpen(0, zName, id, 
             ((flags|SQLITE_OPEN_READONLY)&~SQLITE_OPEN_READWRITE), pOutFlags);
    }else{

#define MX_DELETION_ATTEMPTS 5
static int winDelete(
  sqlite3_vfs *pVfs,          /* Not used on win32 */
  const char *zFilename,      /* Name of file to delete */
  int syncDir                 /* Not used on win32 */
){
  int cnt = 0;
  int rc;
  DWORD rc;
  DWORD error;
  void *zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return SQLITE_NOMEM;
  }
  SimulateIOError(return SQLITE_IOERR_DELETE);
  if( isNT() ){
    do{
      DeleteFileW(zConverted);
    }while(   (   ((rc = GetFileAttributesW(zConverted)) != INVALID_FILE_ATTRIBUTES)
               || ((error = GetLastError()) == ERROR_ACCESS_DENIED))
           && (cnt++ < MX_DELETION_ATTEMPTS)
           && (++cnt < MX_DELETION_ATTEMPTS)
           && (Sleep(100), 1) );
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    do{
      DeleteFileA(zConverted);
    }while(   (   ((rc = GetFileAttributesA(zConverted)) != INVALID_FILE_ATTRIBUTES)
               || ((error = GetLastError()) == ERROR_ACCESS_DENIED))
           && (cnt++ < MX_DELETION_ATTEMPTS)
           && (++cnt < MX_DELETION_ATTEMPTS)
           && (Sleep(100), 1) );
#endif
  }
  free(zConverted);
  OSTRACE2("DELETE \"%s\"\n", zFilename);
  return (   (rc==INVALID_FILE_ATTRIBUTES) 
  return (   (rc == INVALID_FILE_ATTRIBUTES) 
          && (error == ERROR_FILE_NOT_FOUND)) ? SQLITE_OK : SQLITE_IOERR_DELETE;
}

/*
** Check the existance and status of a file.
*/
static int winAccess(
  sqlite3_vfs *pVfs,         /* Not used on win32 */
  const char *zFilename,     /* Name of file to check */
  int flags,                 /* Type of test to make on this file */
  int *pResOut               /* OUT: Result */
){
  DWORD attr;
  int rc;
  void *zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return SQLITE_NOMEM;
  }
  if( isNT() ){
    attr = GetFileAttributesW((WCHAR*)zConverted);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    attr = GetFileAttributesA((char*)zConverted);
#endif
  }
  free(zConverted);
  switch( flags ){
    case SQLITE_ACCESS_READ:
    case SQLITE_ACCESS_EXISTS:
      rc = attr!=INVALID_FILE_ATTRIBUTES;
      break;

      free(zConverted);
      return SQLITE_NOMEM;
    }
    GetFullPathNameW((WCHAR*)zConverted, nByte, zTemp, 0);
    free(zConverted);
    zOut = unicodeToUtf8(zTemp);
    free(zTemp);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    char *zTemp;
    nByte = GetFullPathNameA((char*)zConverted, 0, 0, 0) + 3;
    zTemp = malloc( nByte*sizeof(zTemp[0]) );
    if( zTemp==0 ){
      free(zConverted);
      return SQLITE_NOMEM;
    }
    GetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
    free(zConverted);
    zOut = mbcsToUtf8(zTemp);
    free(zTemp);
#endif
  }
  if( zOut ){
    sqlite3_snprintf(pVfs->mxPathname, zFull, "%s", zOut);
    free(zOut);
    return SQLITE_OK;
  }else{
    return SQLITE_NOMEM;

  HANDLE h;
  void *zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return 0;
  }
  if( isNT() ){
    h = LoadLibraryW((WCHAR*)zConverted);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
** Since the ASCII version of these Windows API do not exist for WINCE,
** it's important to not reference them for WINCE builds.
*/
#if SQLITE_OS_WINCE==0
  }else{
    h = LoadLibraryA((char*)zConverted);
#endif
  }
  free(zConverted);
  return (void*)h;
}
static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
  getLastErrorMsg(nBuf, zBufOut);
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file implements an object that represents a fixed-length
** bitmap.  Bits are numbered starting with 1.
**
** A bitmap is used to record what pages a database file have been
** journalled during a transaction.  Usually only a few pages are
** journalled.  So the bitmap is usually sparse and has low cardinality.
** A bitmap is used to record which pages of a database file have been
** journalled during a transaction, or which pages have the "dont-write"
** property.  Usually only a few pages are meet either condition.
** So the bitmap is usually sparse and has low cardinality.
** But sometimes (for example when during a DROP of a large table) most
** or all of the pages get journalled.  In those cases, the bitmap becomes
** dense.  The algorithm needs to handle both cases well.
** or all of the pages in a database can get journalled.  In those cases, 
** the bitmap becomes dense with high cardinality.  The algorithm needs 
** to handle both cases well.
**
** The size of the bitmap is fixed when the object is created.
**
** All bits are clear when the bitmap is created.  Individual bits
** may be set or cleared one at a time.
**
** Test operations are about 100 times more common that set operations.
** Clear operations are exceedingly rare.  There are usually between
** 5 and 500 set operations per Bitvec object, though the number of sets can
** sometimes grow into tens of thousands or larger.  The size of the
** Bitvec object is the number of pages in the database file at the
** start of a transaction, and is thus usually less than a few thousand,
** but can be as large as 2 billion for a really big database.
**
** @(#) $Id: bitvec.c,v 1.6 2008/06/20 14:59:51 danielk1977 Exp $
** @(#) $Id: bitvec.c,v 1.8 2008/11/11 15:48:48 drh Exp $
*/

#define BITVEC_SZ        512
/* Round the union size down to the nearest pointer boundary, since that's how 
** it will be aligned within the Bitvec struct. */
#define BITVEC_USIZE     (((BITVEC_SZ-12)/sizeof(Bitvec*))*sizeof(Bitvec*))
#define BITVEC_NCHAR     BITVEC_USIZE

    return 0;
  }
}

/*
** Set the i-th bit.  Return 0 on success and an error code if
** anything goes wrong.
**
** This routine might cause sub-bitmaps to be allocated.  Failing
** to get the memory needed to hold the sub-bitmap is the only
** that can go wrong with an insert, assuming p and i are valid.
**
** The calling function must ensure that p is a valid Bitvec object
** and that the value for "i" is within range of the Bitvec object.
** Otherwise the behavior is undefined.
*/
SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec *p, u32 i){
  u32 h;
  assert( p!=0 );
  assert( i>0 );
  assert( i<=p->iSize );
  if( p->iSize<=BITVEC_NBIT ){

  while( p->u.aHash[h] ){
    if( p->u.aHash[h]==i ) return SQLITE_OK;
    h++;
    if( h==BITVEC_NINT ) h = 0;
  }
  p->nSet++;
  if( p->nSet>=BITVEC_MXHASH ){
    unsigned int j;
    int j, rc;
    int rc;
    u32 aiValues[BITVEC_NINT];
    memcpy(aiValues, p->u.aHash, sizeof(aiValues));
    memset(p->u.apSub, 0, sizeof(p->u.apSub[0])*BITVEC_NPTR);
    p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;
    rc = sqlite3BitvecSet(p, i);
    for(j=0; j<BITVEC_NINT; j++){
      if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);

  }else if( p->iDivisor ){
    u32 bin = (i-1)/p->iDivisor;
    i = (i-1)%p->iDivisor + 1;
    if( p->u.apSub[bin] ){
      sqlite3BitvecClear(p->u.apSub[bin], i);
    }
  }else{
    int j;
    unsigned int j;
    u32 aiValues[BITVEC_NINT];
    memcpy(aiValues, p->u.aHash, sizeof(aiValues));
    memset(p->u.aHash, 0, sizeof(p->u.aHash[0])*BITVEC_NINT);
    p->nSet = 0;
    for(j=0; j<BITVEC_NINT; j++){
      if( aiValues[j] && aiValues[j]!=i ){
        sqlite3BitvecSet(p, aiValues[j]);
      }
    }
  }
}

/*
** Destroy a bitmap object.  Reclaim all memory used.
*/
SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec *p){
  if( p==0 ) return;
  if( p->iDivisor ){
    int i;
    unsigned int i;
    for(i=0; i<BITVEC_NPTR; i++){
      sqlite3BitvecDestroy(p->u.apSub[i]);
    }
  }
  sqlite3_free(p);
}

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file implements that page cache.
**
** @(#) $Id: pcache.c,v 1.31 2008/09/21 15:14:04 drh Exp $
** @(#) $Id: pcache.c,v 1.36 2008/11/11 18:43:00 danielk1977 Exp $
*/

/*
** A complete page cache is an instance of this structure.
**
** A cache may only be deleted by its owner and while holding the
** SQLITE_MUTEX_STATUS_LRU mutex.

  ** the cache owner or by any thread holding the the mutex.  Non-owner
  ** threads must hold the mutex when reading these elements to prevent
  ** the entire PCache object from being deleted during the read.
  */
  int szPage;                         /* Size of every page in this cache */
  int szExtra;                        /* Size of extra space for each page */
  int bPurgeable;                     /* True if pages are on backing store */
  void (*xDestroy)(PgHdr*);           /* Called when refcnt goes 1->0 */
  int (*xStress)(void*,PgHdr*);       /* Call to try make a page clean */
  void *pStress;                      /* Argument to xStress */
  /**********************************************************************
  ** The final group of elements can only be accessed while holding the
  ** mutex.  Both the cache owner and any other thread must hold the mutex
  ** to read or write any of these elements.
  */

** Deallocate a page
*/
static void pcachePageFree(PgHdr *p){
  assert( sqlite3_mutex_held(pcache_g.mutex) );
  if( p->pCache->bPurgeable ){
    pcache_g.nCurrentPage--;
  }
  pcacheFree(p->apSave[0]);
  pcacheFree(p->apSave[1]);
  pcacheFree(p);
}

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*
** Return the number of bytes that will be returned to the heap when
** the argument is passed to pcachePageFree().
*/
static int pcachePageSize(PgHdr *p){
  assert( sqlite3_mutex_held(pcache_g.mutex) );
  assert( !pcache_g.pStart );
  assert( p->apSave[0]==0 );
  assert( p->apSave[1]==0 );
  assert( p && p->pCache );
  return sqlite3MallocSize(p);
}
#endif

/*
** Attempt to 'recycle' a page from the global LRU list. Only clean,
** unreferenced pages from purgeable caches are eligible for recycling.
**
** This function removes page pcache.pLruTail from the global LRU list,
** and from the hash-table and PCache.pClean list of the owner pcache.
** There should be no other references to the page.
**
** A pointer to the recycled page is returned, or NULL if no page is
** eligible for recycling.
*/
static PgHdr *pcacheRecyclePage(){
static PgHdr *pcacheRecyclePage(void){
  PgHdr *p = 0;
  assert( sqlite3_mutex_held(pcache_g.mutex) );

  if( (p=pcache_g.pLruTail) ){
  if( (p=pcache_g.pLruTail)!=0 ){
    assert( (p->flags&PGHDR_DIRTY)==0 );
    pcacheRemoveFromLruList(p);
    pcacheRemoveFromHash(p);
    pcacheRemoveFromList(&p->pCache->pClean, p);
  }

  return p;

** Create a new PCache object.  Storage space to hold the object
** has already been allocated and is passed in as the p pointer.
*/
SQLITE_PRIVATE void sqlite3PcacheOpen(
  int szPage,                  /* Size of every page */
  int szExtra,                 /* Extra space associated with each page */
  int bPurgeable,              /* True if pages are on backing store */
  void (*xDestroy)(PgHdr*),    /* Called to destroy a page */
  int (*xStress)(void*,PgHdr*),/* Call to try to make pages clean */
  void *pStress,               /* Argument to xStress */
  PCache *p                    /* Preallocated space for the PCache */
){
  assert( pcache_g.isInit );
  memset(p, 0, sizeof(PCache));
  p->szPage = szPage;
  p->szExtra = szExtra;
  p->bPurgeable = bPurgeable;
  p->xDestroy = xDestroy;
  p->xStress = xStress;
  p->pStress = pStress;
  p->nMax = 100;
  p->nMin = 10;

  pcacheEnterMutex();
  if( bPurgeable ){

** move the page to the LRU list if it is clean.
*/
SQLITE_PRIVATE void sqlite3PcacheRelease(PgHdr *p){
  assert( p->nRef>0 );
  p->nRef--;
  if( p->nRef==0 ){
    PCache *pCache = p->pCache;
    if( p->pCache->xDestroy ){
      p->pCache->xDestroy(p);
    }
    pCache->nRef--;
    if( (p->flags&PGHDR_DIRTY)==0 ){
      pCache->nPinned--;
      pcacheEnterMutex();
      if( pcache_g.nCurrentPage>pcache_g.nMaxPage ){
        pcacheRemoveFromList(&pCache->pClean, p);
        pcacheRemoveFromHash(p);

  pcacheAddToList(&pCache->pDirty, p);
  pcacheExitMutex();
  p->flags |= PGHDR_DIRTY;
}

static void pcacheMakeClean(PgHdr *p){
  PCache *pCache = p->pCache;
  assert( p->apSave[0]==0 && p->apSave[1]==0 );
  assert( p->flags & PGHDR_DIRTY );
  pcacheRemoveFromList(&pCache->pDirty, p);
  pcacheAddToList(&pCache->pClean, p);
  p->flags &= ~PGHDR_DIRTY;
  if( p->nRef==0 ){
    pcacheAddToLruList(p);
    pCache->nPinned--;

/*
** Make every page in the cache clean.
*/
SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache *pCache){
  PgHdr *p;
  pcacheEnterMutex();
  while( (p = pCache->pDirty)!=0 ){
    assert( p->apSave[0]==0 && p->apSave[1]==0 );
    pcacheRemoveFromList(&pCache->pDirty, p);
    p->flags &= ~PGHDR_DIRTY;
    pcacheAddToList(&pCache->pClean, p);
    if( p->nRef==0 ){
      pcacheAddToLruList(p);
      pCache->nPinned--;
    }

*/
SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
  assert( p->nRef>0 );
  pcacheEnterMutex();
  pcacheRemoveFromHash(p);
  p->pgno = newPgno;
  if( newPgno==0 ){
    pcacheFree(p->apSave[0]);
    pcacheFree(p->apSave[1]);
    p->apSave[0] = 0;
    p->apSave[1] = 0;
    if( (p->flags & PGHDR_DIRTY) ){
      pcacheMakeClean(p);
    }
    p->flags = PGHDR_REUSE_UNLIKELY;
  }
  pcacheAddToHash(p);
  pcacheExitMutex();

  pcacheExitMutex();
}

/*
** If there are currently more than pcache.nMaxPage pages allocated, try
** to recycle pages to reduce the number allocated to pcache.nMaxPage.
*/
static void pcacheEnforceMaxPage(){
static void pcacheEnforceMaxPage(void){
  PgHdr *p;
  assert( sqlite3_mutex_held(pcache_g.mutex) );
  while( pcache_g.nCurrentPage>pcache_g.nMaxPage && (p = pcacheRecyclePage()) ){
  while( pcache_g.nCurrentPage>pcache_g.nMaxPage
             && (p = pcacheRecyclePage())!=0 ){
    pcachePageFree(p);
  }
}

/*
** Close a cache.
*/

    pcache_g.nMinPage -= pCache->nMin;
    pcacheEnforceMaxPage();
  }
  sqlite3_free(pCache->apHash);
  pcacheExitMutex();
}

/*
** Preserve the content of the page.  It is assumed that the content
** has not been preserved already.
**
** If idJournal==0 then this is for the overall transaction.
** If idJournal==1 then this is for the statement journal.
**
** This routine is used for in-memory databases only.
**
** Return SQLITE_OK or SQLITE_NOMEM if a memory allocation fails.
*/
SQLITE_PRIVATE int sqlite3PcachePreserve(PgHdr *p, int idJournal){
  void *x;
  int sz;
  assert( p->pCache->bPurgeable==0 );
  assert( p->apSave[idJournal]==0 );
  sz = p->pCache->szPage;
  p->apSave[idJournal] = x = sqlite3PageMalloc( sz );
  if( x==0 ) return SQLITE_NOMEM;
  memcpy(x, p->pData, sz);
  return SQLITE_OK;
}

/*
** Commit a change previously preserved.
*/
SQLITE_PRIVATE void sqlite3PcacheCommit(PCache *pCache, int idJournal){
  PgHdr *p;
  int mask = idJournal==0 ? ~PGHDR_IN_JOURNAL : 0xffffff;
  pcacheEnterMutex();     /* Mutex is required to call pcacheFree() */
  for(p=pCache->pDirty; p; p=p->pNext){
    if( p->apSave[idJournal] ){
      pcacheFree(p->apSave[idJournal]);
      p->apSave[idJournal] = 0;
    }
    p->flags &= mask;
  }
  pcacheExitMutex();
}

/*
** Rollback a change previously preserved.
*/
SQLITE_PRIVATE void sqlite3PcacheRollback(
  PCache *pCache,                  /* Pager cache */
  int idJournal,                   /* Which copy to rollback to */
  void (*xReiniter)(PgHdr*)        /* Called on each rolled back page */
){
  PgHdr *p;
  int sz;
  int mask = idJournal==0 ? ~PGHDR_IN_JOURNAL : 0xffffff;
  pcacheEnterMutex();     /* Mutex is required to call pcacheFree() */
  sz = pCache->szPage;
  for(p=pCache->pDirty; p; p=p->pNext){
    if( p->apSave[idJournal] ){
      memcpy(p->pData, p->apSave[idJournal], sz);
      pcacheFree(p->apSave[idJournal]);
      p->apSave[idJournal] = 0;
      if( xReiniter ){
        xReiniter(p);
      }
    }
    p->flags &= mask;
  }
  pcacheExitMutex();
}

#ifndef NDEBUG
/* 
** Assert flags settings on all pages.  Debugging only.
*/
SQLITE_PRIVATE void sqlite3PcacheAssertFlags(PCache *pCache, int trueMask, int falseMask){
  PgHdr *p;

/* 
** Return the total number of outstanding page references.
*/
SQLITE_PRIVATE int sqlite3PcacheRefCount(PCache *pCache){
  return pCache->nRef;
}

SQLITE_PRIVATE int sqlite3PcachePageRefcount(PgHdr *p){
  return p->nRef;
}

/* 
** Return the total number of pages in the cache.
*/
SQLITE_PRIVATE int sqlite3PcachePagecount(PCache *pCache){
  assert( pCache->nPage>=0 );
  return pCache->nPage;

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.493 2008/09/19 09:14:44 danielk1977 Exp $
** @(#) $Id: pager.c,v 1.502 2008/11/07 00:24:54 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO

/*
** Macros for troubleshooting.  Normally turned off
*/
#if 0

  sqlite3_file *stfd;         /* File descriptor for the statement subjournal*/
  BusyHandler *pBusyHandler;  /* Pointer to sqlite.busyHandler */
  i64 journalOff;             /* Current byte offset in the journal file */
  i64 journalHdr;             /* Byte offset to previous journal header */
  i64 stmtHdrOff;             /* First journal header written this statement */
  i64 stmtCksum;              /* cksumInit when statement was started */
  i64 stmtJSize;              /* Size of journal at stmt_begin() */
  int sectorSize;             /* Assumed sector size during rollback */
  u32 sectorSize;             /* Assumed sector size during rollback */
#ifdef SQLITE_TEST
  int nHit, nMiss;            /* Cache hits and missing */
  int nRead, nWrite;          /* Database pages read/written */
#endif
  void (*xReiniter)(DbPage*); /* Call this routine when reloading pages */
#ifdef SQLITE_HAS_CODEC
  void *(*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */

/*
** Return true if page *pPg has already been written to the statement
** journal (or statement snapshot has been created, if *pPg is part
** of an in-memory database).
*/
static int pageInStatement(PgHdr *pPg){
  Pager *pPager = pPg->pPager;
  if( MEMDB ){
    return pPg->apSave[1]!=0;
  }else{
    return sqlite3BitvecTest(pPager->pInStmt, pPg->pgno);
  return sqlite3BitvecTest(pPager->pInStmt, pPg->pgno);
  }
}

/*
** Read a 32-bit integer from the given file descriptor.  Store the integer
** that is read in *pRes.  Return SQLITE_OK if everything worked, or an
** error code is something goes wrong.
**

** The CHECK_PAGE macro takes a PgHdr* as an argument. If SQLITE_CHECK_PAGES
** is defined, and NDEBUG is not defined, an assert() statement checks
** that the page is either dirty or still matches the calculated page-hash.
*/
#define CHECK_PAGE(x) checkPage(x)
static void checkPage(PgHdr *pPg){
  Pager *pPager = pPg->pPager;
  assert( !pPg->pageHash || pPager->errCode || MEMDB 
  assert( !pPg->pageHash || pPager->errCode
      || (pPg->flags&PGHDR_DIRTY) || pPg->pageHash==pager_pagehash(pPg) );
}

#else
#define pager_datahash(X,Y)  0
#define pager_pagehash(X)  0
#define CHECK_PAGE(x)

  **   * When the pager is in no-sync mode. Corruption can follow a
  **     power failure in this case anyway.
  **
  **   * When the SQLITE_IOCAP_SAFE_APPEND flag is set. This guarantees
  **     that garbage data is never appended to the journal file.
  */
  assert(pPager->fd->pMethods||pPager->noSync);
  if( (pPager->noSync) 
  if( (pPager->noSync) || (pPager->journalMode==PAGER_JOURNALMODE_MEMORY)
   || (sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_SAFE_APPEND) 
  ){
    put32bits(&zHeader[sizeof(aJournalMagic)], 0xffffffff);
  }else{
    put32bits(&zHeader[sizeof(aJournalMagic)], 0);
  }

  /* Update the assumed sector-size to match the value used by 
  ** the process that created this journal. If this journal was
  ** created by a process other than this one, then this routine
  ** is being called from within pager_playback(). The local value
  ** of Pager.sectorSize is restored at the end of that routine.
  */
  rc = read32bits(pPager->jfd, jrnlOff+12, (u32 *)&pPager->sectorSize);
  rc = read32bits(pPager->jfd, jrnlOff+12, &pPager->sectorSize);
  if( rc ) return rc;
  if( (pPager->sectorSize & (pPager->sectorSize-1))!=0
         || pPager->sectorSize>0x1000000 ){
    return SQLITE_DONE;
  }

  pPager->journalOff += JOURNAL_HDR_SZ(pPager);
  return SQLITE_OK;
}


/*

  int len; 
  int i; 
  i64 jrnlOff;
  i64 jrnlSize;
  u32 cksum = 0;
  char zBuf[sizeof(aJournalMagic)+2*4];

  if( !zMaster || pPager->setMaster) return SQLITE_OK;
  if( !zMaster || pPager->setMaster ) return SQLITE_OK;
  if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ) return SQLITE_OK;
  pPager->setMaster = 1;

  len = strlen(zMaster);
  for(i=0; i<len; i++){
    cksum += zMaster[i];
  }

** the cache and reset the Pager structure internal state. If there is
** an open journal-file, then the next time a shared-lock is obtained
** on the pager file (by this or any other process), it will be
** treated as a hot-journal and rolled back.
*/
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    if( !MEMDB ){
      int rc = osUnlock(pPager->fd, NO_LOCK);
      if( rc ) pPager->errCode = rc;
      pPager->dbSize = -1;
      IOTRACE(("UNLOCK %p\n", pPager))
    int rc = osUnlock(pPager->fd, NO_LOCK);
    if( rc ) pPager->errCode = rc;
    pPager->dbSize = -1;
    IOTRACE(("UNLOCK %p\n", pPager))

      /* Always close the journal file when dropping the database lock.
      ** Otherwise, another connection with journal_mode=delete might
      ** delete the file out from under us.
      */
      if( pPager->journalOpen ){
        sqlite3OsClose(pPager->jfd);
        pPager->journalOpen = 0;
        sqlite3BitvecDestroy(pPager->pInJournal);
        pPager->pInJournal = 0;
        sqlite3BitvecDestroy(pPager->pAlwaysRollback);
        pPager->pAlwaysRollback = 0;
      }
    /* Always close the journal file when dropping the database lock.
    ** Otherwise, another connection with journal_mode=delete might
    ** delete the file out from under us.
    */
    if( pPager->journalOpen ){
      sqlite3OsClose(pPager->jfd);
      pPager->journalOpen = 0;
      sqlite3BitvecDestroy(pPager->pInJournal);
      pPager->pInJournal = 0;
      sqlite3BitvecDestroy(pPager->pAlwaysRollback);
      pPager->pAlwaysRollback = 0;
    }

      /* If Pager.errCode is set, the contents of the pager cache cannot be
      ** trusted. Now that the pager file is unlocked, the contents of the
      ** cache can be discarded and the error code safely cleared.
      */
      if( pPager->errCode ){
        if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
        pager_reset(pPager);
        if( pPager->stmtOpen ){
          sqlite3OsClose(pPager->stfd);
          sqlite3BitvecDestroy(pPager->pInStmt);
          pPager->pInStmt = 0;
        }
        pPager->stmtOpen = 0;
        pPager->stmtInUse = 0;
        pPager->journalOff = 0;
        pPager->journalStarted = 0;
        pPager->stmtAutoopen = 0;
        pPager->origDbSize = 0;
      }
    }
    /* If Pager.errCode is set, the contents of the pager cache cannot be
    ** trusted. Now that the pager file is unlocked, the contents of the
    ** cache can be discarded and the error code safely cleared.
    */
    if( pPager->errCode ){
      if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
      pager_reset(pPager);
      if( pPager->stmtOpen ){
        sqlite3OsClose(pPager->stfd);
        sqlite3BitvecDestroy(pPager->pInStmt);
        pPager->pInStmt = 0;
      }
      pPager->stmtOpen = 0;
      pPager->stmtInUse = 0;
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
      pPager->stmtAutoopen = 0;
      pPager->origDbSize = 0;
    }


    if( !MEMDB || pPager->errCode==SQLITE_OK ){
      pPager->state = PAGER_UNLOCK;
      pPager->changeCountDone = 0;
    pPager->state = PAGER_UNLOCK;
    pPager->changeCountDone = 0;
    }
  }
}

/*
** Execute a rollback if a transaction is active and unlock the 
** database file. If the pager has already entered the error state, 
** do not attempt the rollback.

** TODO: Consider keeping the journal file open for temporary databases.
** This might give a performance improvement on windows where opening
** a file is an expensive operation.
*/
static int pager_end_transaction(Pager *pPager, int hasMaster){
  int rc = SQLITE_OK;
  int rc2 = SQLITE_OK;
  assert( !MEMDB );
  if( pPager->state<PAGER_RESERVED ){
    return SQLITE_OK;
  }
  sqlite3PagerStmtCommit(pPager);
  if( pPager->stmtOpen && !pPager->exclusiveMode ){
    sqlite3OsClose(pPager->stfd);
    pPager->stmtOpen = 0;
  }
  if( pPager->journalOpen ){
    if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
      int isMemoryJournal = sqlite3IsMemJournal(pPager->jfd);
      sqlite3OsClose(pPager->jfd);
      pPager->journalOpen = 0;
      if( !isMemoryJournal ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE
         && (rc = sqlite3OsTruncate(pPager->jfd, 0))==SQLITE_OK ){
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    if( pPager->exclusiveMode 
    }else if( pPager->exclusiveMode 
     || pPager->journalMode==PAGER_JOURNALMODE_PERSIST
    ){
      rc = zeroJournalHdr(pPager, hasMaster);
      pager_error(pPager, rc);
      pPager->journalOff = 0;
      pPager->journalStarted = 0;
    }else{
      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE || rc );
      sqlite3OsClose(pPager->jfd);
      pPager->journalOpen = 0;
      if( rc==SQLITE_OK && !pPager->tempFile ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }
    sqlite3BitvecDestroy(pPager->pInJournal);

  }else if( pPager->state==PAGER_SYNCED ){
    pPager->state = PAGER_EXCLUSIVE;
  }
  pPager->origDbSize = 0;
  pPager->setMaster = 0;
  pPager->needSync = 0;
  /* lruListSetFirstSynced(pPager); */
  if( !MEMDB ){
  pPager->dbSize = -1;
    pPager->dbSize = -1;
  }
  pPager->dbModified = 0;

  return (rc==SQLITE_OK?rc2:rc);
}

/*
** Compute and return a checksum for the page of data.

          pPager->journalOff = szJ;
          break;
        }else{
          /* If we are unable to rollback, then the database is probably
          ** going to end up being corrupt.  It is corrupt to us, anyhow.
          ** Perhaps the next process to come along can fix it....
          */
          rc = SQLITE_CORRUPT;
          rc = SQLITE_CORRUPT_BKPT;
          goto end_playback;
        }
      }
    }
  }
  /*NOTREACHED*/
  assert( 0 );

end_playback:
  if( rc==SQLITE_OK ){
    zMaster = pPager->pTmpSpace;
    rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);
  }
  if( rc==SQLITE_OK ){
    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
  }
  if( rc==SQLITE_OK && zMaster[0] ){
  if( rc==SQLITE_OK && zMaster[0] && res ){
    /* If there was a master journal and this routine will return success,
    ** see if it is possible to delete the master journal.
    */
    rc = pager_delmaster(pPager, zMaster);
  }

  /* The Pager.sectorSize variable may have been updated while rolling

**              point of causing damage to the database during rollback.
**
** Numeric values associated with these states are OFF==1, NORMAL=2,
** and FULL=3.
*/
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
SQLITE_PRIVATE void sqlite3PagerSetSafetyLevel(Pager *pPager, int level, int bFullFsync){
  pPager->noSync =  level==1 || pPager->tempFile || MEMDB;
  pPager->noSync =  level==1 || pPager->tempFile;
  pPager->fullSync = level==3 && !pPager->tempFile;
  pPager->sync_flags = (bFullFsync?SQLITE_SYNC_FULL:SQLITE_SYNC_NORMAL);
  if( pPager->noSync ) pPager->needSync = 0;
}
#endif

/*

** It is never written to disk.  This can be used to implement an
** in-memory database.
*/
SQLITE_PRIVATE int sqlite3PagerOpen(
  sqlite3_vfs *pVfs,       /* The virtual file system to use */
  Pager **ppPager,         /* Return the Pager structure here */
  const char *zFilename,   /* Name of the database file to open */
  void (*xDesc)(DbPage*),  /* Page destructor function */
  int nExtra,              /* Extra bytes append to each in-memory page */
  int flags,               /* flags controlling this file */
  int vfsFlags             /* flags passed through to sqlite3_vfs.xOpen() */
){
  u8 *pPtr;
  Pager *pPager = 0;
  int rc = SQLITE_OK;
  int i;
  int tempFile = 0;
  int memDb = 0;
  int readOnly = 0;
  int useJournal = (flags & PAGER_OMIT_JOURNAL)==0;
  int noReadlock = (flags & PAGER_NO_READLOCK)!=0;
  int journalFileSize = sqlite3JournalSize(pVfs);
  int journalFileSize;
  int pcacheSize = sqlite3PcacheSize();
  int szPageDflt = SQLITE_DEFAULT_PAGE_SIZE;
  char *zPathname = 0;
  int nPathname = 0;

  if( sqlite3JournalSize(pVfs)>sqlite3MemJournalSize() ){
    journalFileSize = sqlite3JournalSize(pVfs);
  }else{
    journalFileSize = sqlite3MemJournalSize();
  }

  /* The default return is a NULL pointer */
  *ppPager = 0;

  /* Compute and store the full pathname in an allocated buffer pointed
  ** to by zPathname, length nPathname. Or, if this is a temporary file,
  ** leave both nPathname and zPathname set to 0.
  */
  if( zFilename && zFilename[0] ){
    nPathname = pVfs->mxPathname+1;
    zPathname = sqlite3Malloc(nPathname*2);
    if( zPathname==0 ){
      return SQLITE_NOMEM;
    }
#ifndef SQLITE_OMIT_MEMORYDB
    if( strcmp(zFilename,":memory:")==0 ){
      memDb = 1;
      zPathname[0] = 0;
      useJournal = 0;
    }else
#endif
    {
      rc = sqlite3OsFullPathname(pVfs, zFilename, nPathname, zPathname);
    }
    if( rc!=SQLITE_OK ){
      sqlite3_free(zPathname);
      return rc;
    }
    nPathname = strlen(zPathname);
  }

  /* Allocate memory for the pager structure */
  pPager = sqlite3MallocZero(
    sizeof(*pPager) +           /* Pager structure */
    pcacheSize      +           /* PCache object */
    journalFileSize +           /* The journal file structure */ 
    pVfs->szOsFile  +           /* The main db file */
    pVfs->szOsFile * 3 +        /* The main db and two journal files */ 
    journalFileSize * 2 +       /* The two journal files */ 
    3*nPathname + 40            /* zFilename, zDirectory, zJournal */
  );
  if( !pPager ){
    sqlite3_free(zPathname);
    return SQLITE_NOMEM;
  }
  pPager->pPCache = (PCache *)&pPager[1];
  pPtr = ((u8 *)&pPager[1]) + pcacheSize;
  pPager->vfsFlags = vfsFlags;
  pPager->fd = (sqlite3_file*)&pPtr[pVfs->szOsFile*0];
  pPager->stfd = (sqlite3_file*)&pPtr[pVfs->szOsFile*1];
  pPager->jfd = (sqlite3_file*)&pPtr[pVfs->szOsFile*2];
  pPager->zFilename = (char*)&pPtr[pVfs->szOsFile*2+journalFileSize];
  pPager->stfd = (sqlite3_file*)&pPtr[pVfs->szOsFile];
  pPager->jfd = (sqlite3_file*)&pPtr[pVfs->szOsFile+journalFileSize];
  pPager->zFilename = (char*)&pPtr[pVfs->szOsFile+2*journalFileSize];
  pPager->zDirectory = &pPager->zFilename[nPathname+1];
  pPager->zJournal = &pPager->zDirectory[nPathname+1];
  pPager->pVfs = pVfs;
  if( zPathname ){
    memcpy(pPager->zFilename, zPathname, nPathname+1);
    sqlite3_free(zPathname);
  }

        }
#endif
        if( szPageDflt>SQLITE_MAX_DEFAULT_PAGE_SIZE ){
          szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;
        }
      }
    }
  }else if( !memDb ){
  }else{
    /* If a temporary file is requested, it is not opened immediately.
    ** In this case we accept the default page size and delay actually
    ** opening the file until the first call to OsWrite().
    **
    ** This branch is also run for an in-memory database. An in-memory
    ** database is the same as a temp-file that is never written out to
    ** disk and uses an in-memory rollback journal.
    */ 
    tempFile = 1;
    pPager->state = PAGER_EXCLUSIVE;
  }

  if( pPager && rc==SQLITE_OK ){
    pPager->pTmpSpace = sqlite3PageMalloc(szPageDflt);
  }

  /* If an error occured in either of the blocks above.
  ** Free the Pager structure and close the file.
  ** Since the pager is not allocated there is no need to set 
  ** any Pager.errMask variables.
  */
  if( !pPager || !pPager->pTmpSpace ){
    sqlite3OsClose(pPager->fd);
    sqlite3_free(pPager);
    return ((rc==SQLITE_OK)?SQLITE_NOMEM:rc);
  }
  nExtra = FORCE_ALIGNMENT(nExtra);
  sqlite3PcacheOpen(szPageDflt, nExtra, !memDb, xDesc, 
  sqlite3PcacheOpen(szPageDflt, nExtra, !memDb,
                    !memDb?pagerStress:0, (void *)pPager, pPager->pPCache);

  PAGERTRACE3("OPEN %d %s\n", FILEHANDLEID(pPager->fd), pPager->zFilename);
  IOTRACE(("OPEN %p %s\n", pPager, pPager->zFilename))

  /* Fill in Pager.zDirectory[] */
  memcpy(pPager->zDirectory, pPager->zFilename, nPathname+1);

  pPager->fullSync = (pPager->noSync?0:1);
  pPager->sync_flags = SQLITE_SYNC_NORMAL;
  /* pPager->pFirst = 0; */
  /* pPager->pFirstSynced = 0; */
  /* pPager->pLast = 0; */
  pPager->nExtra = nExtra;
  pPager->journalSizeLimit = SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT;
  assert(pPager->fd->pMethods||memDb||tempFile);
  assert(pPager->fd->pMethods||tempFile);
  if( !memDb ){
    setSectorSize(pPager);
  setSectorSize(pPager);
  if( memDb ){
    pPager->journalMode = PAGER_JOURNALMODE_MEMORY;
  }
  /* pPager->pBusyHandler = 0; */
  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
  *ppPager = pPager;
  return SQLITE_OK;
}

** these cases sqlite3OsRead() will return an error, to which the correct 
** response is to zero the memory at pDest and continue.  A real IO error 
** will presumably recur and be picked up later (Todo: Think about this).
*/
SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager *pPager, int N, unsigned char *pDest){
  int rc = SQLITE_OK;
  memset(pDest, 0, N);
  assert(MEMDB||pPager->fd->pMethods||pPager->tempFile);
  assert(pPager->fd->pMethods||pPager->tempFile);
  if( pPager->fd->pMethods ){
    IOTRACE(("DBHDR %p 0 %d\n", pPager, N))
    rc = sqlite3OsRead(pPager->fd, pDest, N, 0);
    if( rc==SQLITE_IOERR_SHORT_READ ){
      rc = SQLITE_OK;
    }
  }

  /* The OS lock values must be the same as the Pager lock values */
  assert( PAGER_SHARED==SHARED_LOCK );
  assert( PAGER_RESERVED==RESERVED_LOCK );
  assert( PAGER_EXCLUSIVE==EXCLUSIVE_LOCK );

  /* If the file is currently unlocked then the size must be unknown */
  assert( pPager->state>=PAGER_SHARED || pPager->dbSize<0 || MEMDB );
  assert( pPager->state>=PAGER_SHARED || pPager->dbSize<0 );

  if( pPager->state>=locktype ){
    rc = SQLITE_OK;
  }else{
    if( pPager->pBusyHandler ) pPager->pBusyHandler->nBusy = 0;
    do {
      rc = sqlite3OsLock(pPager->fd, locktype);

}

/*
** Truncate the file to the number of pages specified.
*/
SQLITE_PRIVATE int sqlite3PagerTruncate(Pager *pPager, Pgno nPage){
  int rc = SQLITE_OK;
  assert( pPager->state>=PAGER_SHARED || MEMDB );
  assert( pPager->state>=PAGER_SHARED );


  sqlite3PagerPagecount(pPager, 0);
  if( pPager->errCode ){
    rc = pPager->errCode;
  }else if( nPage<(unsigned)pPager->dbSize ){
    if( MEMDB ){
      pPager->dbSize = nPage;
      pager_truncate_cache(pPager);
    }else{
      rc = syncJournal(pPager);
      if( rc==SQLITE_OK ){
        /* Get an exclusive lock on the database before truncating. */
        rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
      }
      if( rc==SQLITE_OK ){
        rc = pager_truncate(pPager, nPage);
    rc = syncJournal(pPager);
    if( rc==SQLITE_OK ){
      /* Get an exclusive lock on the database before truncating. */
      rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
    }
    if( rc==SQLITE_OK ){
      rc = pager_truncate(pPager, nPage);
      }
    }
  }

  return rc;
}

/*

SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager){

  disable_simulated_io_errors();
  sqlite3BeginBenignMalloc();
  pPager->errCode = 0;
  pPager->exclusiveMode = 0;
  pager_reset(pPager);
  if( !MEMDB ){
  pagerUnlockAndRollback(pPager);
    pagerUnlockAndRollback(pPager);
  }
  enable_simulated_io_errors();
  sqlite3EndBenignMalloc();
  PAGERTRACE2("CLOSE %d\n", PAGERID(pPager));
  IOTRACE(("CLOSE %p\n", pPager))
  if( pPager->journalOpen ){
    sqlite3OsClose(pPager->jfd);
  }

static int syncJournal(Pager *pPager){
  int rc = SQLITE_OK;

  /* Sync the journal before modifying the main database
  ** (assuming there is a journal and it needs to be synced.)
  */
  if( pPager->needSync ){
    if( !pPager->tempFile ){
    assert( !pPager->tempFile );
    if( pPager->journalMode!=PAGER_JOURNALMODE_MEMORY ){
      int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
      assert( pPager->journalOpen );

      if( 0==(iDc&SQLITE_IOCAP_SAFE_APPEND) ){
        /* Write the nRec value into the journal file header. If in
        ** full-synchronous mode, sync the journal first. This ensures that
        ** all data has really hit the disk before nRec is updated to mark

  }

  assert( pPg->flags&PGHDR_DIRTY );
  if( pPager->errCode==SQLITE_OK ){
    if( pPg->flags&PGHDR_NEED_SYNC ){
      rc = syncJournal(pPager);
      if( rc==SQLITE_OK && pPager->fullSync && 
        !(pPager->journalMode==PAGER_JOURNALMODE_MEMORY) &&
        !(sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_SAFE_APPEND)
      ){
        pPager->nRec = 0;
        rc = writeJournalHdr(pPager);
      }
    }
    if( rc==SQLITE_OK ){

  */
  if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
    return pPager->errCode;
  }

  if( pPager->state==PAGER_UNLOCK || isErrorReset ){
    sqlite3_vfs *pVfs = pPager->pVfs;
    if( !MEMDB ){
      int isHotJournal;
      assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
      if( !pPager->noReadlock ){
        rc = pager_wait_on_lock(pPager, SHARED_LOCK);
        if( rc!=SQLITE_OK ){
          assert( pPager->state==PAGER_UNLOCK );
          return pager_error(pPager, rc);
        }
        assert( pPager->state>=SHARED_LOCK );
      }
  
      /* If a journal file exists, and there is no RESERVED lock on the
      ** database file, then it either needs to be played back or deleted.
      */
      if( !isErrorReset ){
        rc = hasHotJournal(pPager, &isHotJournal);
        if( rc!=SQLITE_OK ){
          goto failed;
        }
      }
      if( isErrorReset || isHotJournal ){
        /* Get an EXCLUSIVE lock on the database file. At this point it is
        ** important that a RESERVED lock is not obtained on the way to the
        ** EXCLUSIVE lock. If it were, another process might open the
        ** database file, detect the RESERVED lock, and conclude that the
        ** database is safe to read while this process is still rolling it 
        ** back.
        ** 
        ** Because the intermediate RESERVED lock is not requested, the
        ** second process will get to this point in the code and fail to
        ** obtain its own EXCLUSIVE lock on the database file.
        */
        if( pPager->state<EXCLUSIVE_LOCK ){
          rc = sqlite3OsLock(pPager->fd, EXCLUSIVE_LOCK);
          if( rc!=SQLITE_OK ){
            rc = pager_error(pPager, rc);
            goto failed;
          }
          pPager->state = PAGER_EXCLUSIVE;
        }
    int isHotJournal;
    assert( !MEMDB );
    assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
    if( !pPager->noReadlock ){
      rc = pager_wait_on_lock(pPager, SHARED_LOCK);
      if( rc!=SQLITE_OK ){
        assert( pPager->state==PAGER_UNLOCK );
        return pager_error(pPager, rc);
      }
      assert( pPager->state>=SHARED_LOCK );
    }

    /* If a journal file exists, and there is no RESERVED lock on the
    ** database file, then it either needs to be played back or deleted.
    */
    if( !isErrorReset ){
      rc = hasHotJournal(pPager, &isHotJournal);
      if( rc!=SQLITE_OK ){
        goto failed;
      }
    }
    if( isErrorReset || isHotJournal ){
      /* Get an EXCLUSIVE lock on the database file. At this point it is
      ** important that a RESERVED lock is not obtained on the way to the
      ** EXCLUSIVE lock. If it were, another process might open the
      ** database file, detect the RESERVED lock, and conclude that the
      ** database is safe to read while this process is still rolling it 
      ** back.
      ** 
      ** Because the intermediate RESERVED lock is not requested, the
      ** second process will get to this point in the code and fail to
      ** obtain its own EXCLUSIVE lock on the database file.
      */
      if( pPager->state<EXCLUSIVE_LOCK ){
        rc = sqlite3OsLock(pPager->fd, EXCLUSIVE_LOCK);
        if( rc!=SQLITE_OK ){
          rc = pager_error(pPager, rc);
          goto failed;
        }
        pPager->state = PAGER_EXCLUSIVE;
      }
 
        /* Open the journal for read/write access. This is because in 
        ** exclusive-access mode the file descriptor will be kept open and
        ** possibly used for a transaction later on. On some systems, the
        ** OsTruncate() call used in exclusive-access mode also requires
        ** a read/write file handle.
        */
        if( !isErrorReset && pPager->journalOpen==0 ){
          int res;
          rc = sqlite3OsAccess(pVfs,pPager->zJournal,SQLITE_ACCESS_EXISTS,&res);
          if( rc==SQLITE_OK ){
            if( res ){
              int fout = 0;
              int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
              assert( !pPager->tempFile );
              rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
              assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
              if( fout&SQLITE_OPEN_READONLY ){
                rc = SQLITE_BUSY;
                sqlite3OsClose(pPager->jfd);
              }
            }else{
              /* If the journal does not exist, that means some other process
              ** has already rolled it back */
              rc = SQLITE_BUSY;
            }
          }
        }
        if( rc!=SQLITE_OK ){
      /* Open the journal for read/write access. This is because in 
      ** exclusive-access mode the file descriptor will be kept open and
      ** possibly used for a transaction later on. On some systems, the
      ** OsTruncate() call used in exclusive-access mode also requires
      ** a read/write file handle.
      */
      if( !isErrorReset && pPager->journalOpen==0 ){
        int res;
        rc = sqlite3OsAccess(pVfs,pPager->zJournal,SQLITE_ACCESS_EXISTS,&res);
        if( rc==SQLITE_OK ){
          if( res ){
            int fout = 0;
            int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
            assert( !pPager->tempFile );
            rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
            assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
            if( rc==SQLITE_OK && fout&SQLITE_OPEN_READONLY ){
              rc = SQLITE_CANTOPEN;
              sqlite3OsClose(pPager->jfd);
            }
          }else{
            /* If the journal does not exist, that means some other process
            ** has already rolled it back */
            rc = SQLITE_BUSY;
          }
        }
      }
      if( rc!=SQLITE_OK ){
          if( rc!=SQLITE_NOMEM && rc!=SQLITE_IOERR_UNLOCK 
           && rc!=SQLITE_IOERR_NOMEM 
          ){
            rc = SQLITE_BUSY;
          }
          goto failed;
        }
        pPager->journalOpen = 1;
        pPager->journalStarted = 0;
        pPager->journalOff = 0;
        pPager->setMaster = 0;
        pPager->journalHdr = 0;
        goto failed;
      }
      pPager->journalOpen = 1;
      pPager->journalStarted = 0;
      pPager->journalOff = 0;
      pPager->setMaster = 0;
      pPager->journalHdr = 0;
 
        /* Playback and delete the journal.  Drop the database write
        ** lock and reacquire the read lock.
        */
        rc = pager_playback(pPager, 1);
        if( rc!=SQLITE_OK ){
          rc = pager_error(pPager, rc);
          goto failed;
        }
        assert(pPager->state==PAGER_SHARED || 
            (pPager->exclusiveMode && pPager->state>PAGER_SHARED)
        );
      }
      /* Playback and delete the journal.  Drop the database write
      ** lock and reacquire the read lock.
      */
      rc = pager_playback(pPager, 1);
      if( rc!=SQLITE_OK ){
        rc = pager_error(pPager, rc);
        goto failed;
      }
      assert(pPager->state==PAGER_SHARED || 
          (pPager->exclusiveMode && pPager->state>PAGER_SHARED)
      );
    }

      if( sqlite3PcachePagecount(pPager->pPCache)>0 ){
        /* The shared-lock has just been acquired on the database file
        ** and there are already pages in the cache (from a previous
        ** read or write transaction).  Check to see if the database
        ** has been modified.  If the database has changed, flush the
        ** cache.
        **
        ** Database changes is detected by looking at 15 bytes beginning
        ** at offset 24 into the file.  The first 4 of these 16 bytes are
        ** a 32-bit counter that is incremented with each change.  The
        ** other bytes change randomly with each file change when
        ** a codec is in use.
        ** 
        ** There is a vanishingly small chance that a change will not be 
        ** detected.  The chance of an undetected change is so small that
        ** it can be neglected.
        */
        char dbFileVers[sizeof(pPager->dbFileVers)];
        sqlite3PagerPagecount(pPager, 0);
    if( sqlite3PcachePagecount(pPager->pPCache)>0 ){
      /* The shared-lock has just been acquired on the database file
      ** and there are already pages in the cache (from a previous
      ** read or write transaction).  Check to see if the database
      ** has been modified.  If the database has changed, flush the
      ** cache.
      **
      ** Database changes is detected by looking at 15 bytes beginning
      ** at offset 24 into the file.  The first 4 of these 16 bytes are
      ** a 32-bit counter that is incremented with each change.  The
      ** other bytes change randomly with each file change when
      ** a codec is in use.
      ** 
      ** There is a vanishingly small chance that a change will not be 
      ** detected.  The chance of an undetected change is so small that
      ** it can be neglected.
      */
      char dbFileVers[sizeof(pPager->dbFileVers)];
      sqlite3PagerPagecount(pPager, 0);

        if( pPager->errCode ){
          rc = pPager->errCode;
          goto failed;
        }
      if( pPager->errCode ){
        rc = pPager->errCode;
        goto failed;
      }

        if( pPager->dbSize>0 ){
          IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
          rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
          if( rc!=SQLITE_OK ){
            goto failed;
          }
        }else{
          memset(dbFileVers, 0, sizeof(dbFileVers));
        }
      if( pPager->dbSize>0 ){
        IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
        rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
        if( rc!=SQLITE_OK ){
          goto failed;
        }
      }else{
        memset(dbFileVers, 0, sizeof(dbFileVers));
      }

        if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
          pager_reset(pPager);
      if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
        pager_reset(pPager);
        }
      }
    }
    assert( pPager->exclusiveMode || pPager->state<=PAGER_SHARED );
    if( pPager->state==PAGER_UNLOCK ){
      pPager->state = PAGER_SHARED;
    }
  }

  int noContent       /* Do not bother reading content from disk if true */
){
  PgHdr *pPg = 0;
  int rc;

  assert( pPager->state==PAGER_UNLOCK 
       || sqlite3PcacheRefCount(pPager->pPCache)>0 
       || pgno==1 
       || pgno==1
  );

  /* The maximum page number is 2^31. Return SQLITE_CORRUPT if a page
  ** number greater than this, or zero, is requested.
  */
  if( pgno>PAGER_MAX_PGNO || pgno==0 || pgno==PAGER_MJ_PGNO(pPager) ){
    return SQLITE_CORRUPT_BKPT;

    /* The pager cache has created a new page. Its content needs to 
    ** be initialized.
    */
    int nMax;
    PAGER_INCR(pPager->nMiss);
    pPg->pPager = pPager;
    if( sqlite3BitvecTest(pPager->pInJournal, pgno) ){
      assert( !MEMDB );
      pPg->flags |= PGHDR_IN_JOURNAL;
    }
    memset(pPg->pExtra, 0, pPager->nExtra);

    rc = sqlite3PagerPagecount(pPager, &nMax);
    if( rc!=SQLITE_OK ){
      sqlite3PagerUnref(pPg);

** write lock if anything goes wrong.
*/
static int pager_open_journal(Pager *pPager){
  sqlite3_vfs *pVfs = pPager->pVfs;
  int flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_CREATE);

  int rc;
  assert( !MEMDB );
  assert( pPager->state>=PAGER_RESERVED );
  assert( pPager->useJournal );
  assert( pPager->pInJournal==0 );
  sqlite3PagerPagecount(pPager, 0);
  pPager->pInJournal = sqlite3BitvecCreate(pPager->dbSize);
  if( pPager->pInJournal==0 ){
    rc = SQLITE_NOMEM;
    goto failed_to_open_journal;
  }

  if( pPager->journalOpen==0 ){
    if( pPager->tempFile ){
      flags |= (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL);
    }else{
      flags |= (SQLITE_OPEN_MAIN_JOURNAL);
    }
    if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
      sqlite3MemJournalOpen(pPager->jfd);
      rc = SQLITE_OK;
    }else{
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
    rc = sqlite3JournalOpen(
        pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
    );
      rc = sqlite3JournalOpen(
          pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
      );
#else
    rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
      rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
#endif
    }
    assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
    pPager->journalOff = 0;
    pPager->setMaster = 0;
    pPager->journalHdr = 0;
    if( rc!=SQLITE_OK ){
      if( rc==SQLITE_NOMEM ){
        sqlite3OsDelete(pVfs, pPager->zJournal, 0);

SQLITE_PRIVATE int sqlite3PagerBegin(DbPage *pPg, int exFlag){
  Pager *pPager = pPg->pPager;
  int rc = SQLITE_OK;
  assert( pPg->nRef>0 );
  assert( pPager->state!=PAGER_UNLOCK );
  if( pPager->state==PAGER_SHARED ){
    assert( pPager->pInJournal==0 );
    assert( !MEMDB );
    sqlite3PcacheAssertFlags(pPager->pPCache, 0, PGHDR_IN_JOURNAL);
    if( MEMDB ){
      pPager->state = PAGER_EXCLUSIVE;
      pPager->origDbSize = pPager->dbSize;
    }else{
      rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
      if( rc==SQLITE_OK ){
        pPager->state = PAGER_RESERVED;
        if( exFlag ){
          rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
        }
      }
      if( rc!=SQLITE_OK ){
        return rc;
      }
      pPager->dirtyCache = 0;
      PAGERTRACE2("TRANSACTION %d\n", PAGERID(pPager));
      if( pPager->useJournal && !pPager->tempFile
             && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
        rc = pager_open_journal(pPager);
    rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
    if( rc==SQLITE_OK ){
      pPager->state = PAGER_RESERVED;
      if( exFlag ){
        rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
      }
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
    pPager->dirtyCache = 0;
    PAGERTRACE2("TRANSACTION %d\n", PAGERID(pPager));
    if( pPager->useJournal && !pPager->tempFile
           && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
      rc = pager_open_journal(pPager);
      }
    }
  }else if( pPager->journalOpen && pPager->journalOff==0 ){
    /* This happens when the pager was in exclusive-access mode the last
    ** time a (read or write) transaction was successfully concluded
    ** by this connection. Instead of deleting the journal file it was 
    ** kept open and either was truncated to 0 bytes or its header was
    ** overwritten with zeros.

    pPager->dirtyCache = 1;
    pPager->dbModified = 1;
  
    /* The transaction journal now exists and we have a RESERVED or an
    ** EXCLUSIVE lock on the main database file.  Write the current page to
    ** the transaction journal if it is not there already.
    */
    if( !(pPg->flags&PGHDR_IN_JOURNAL) && (pPager->journalOpen || MEMDB) ){
    if( !(pPg->flags&PGHDR_IN_JOURNAL) && pPager->journalOpen ){
      if( (int)pPg->pgno <= pPager->origDbSize ){
        if( MEMDB ){
          PAGERTRACE3("JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
          rc = sqlite3PcachePreserve(pPg, 0);
          if( rc!=SQLITE_OK ){
            return rc;
          }
        }else{
          u32 cksum;
          char *pData2;
        u32 cksum;
        char *pData2;

          /* We should never write to the journal file the page that
          ** contains the database locks.  The following assert verifies
          ** that we do not. */
          assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
          pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
          cksum = pager_cksum(pPager, (u8*)pData2);
          rc = write32bits(pPager->jfd, pPager->journalOff, pPg->pgno);
          if( rc==SQLITE_OK ){
            rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize,
                                pPager->journalOff + 4);
            pPager->journalOff += pPager->pageSize+4;
          }
          if( rc==SQLITE_OK ){
            rc = write32bits(pPager->jfd, pPager->journalOff, cksum);
            pPager->journalOff += 4;
          }
          IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
                   pPager->journalOff, pPager->pageSize));
          PAGER_INCR(sqlite3_pager_writej_count);
          PAGERTRACE5("JOURNAL %d page %d needSync=%d hash(%08x)\n",
               PAGERID(pPager), pPg->pgno, 
               ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg));
        /* We should never write to the journal file the page that
        ** contains the database locks.  The following assert verifies
        ** that we do not. */
        assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
        pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
        cksum = pager_cksum(pPager, (u8*)pData2);
        rc = write32bits(pPager->jfd, pPager->journalOff, pPg->pgno);
        if( rc==SQLITE_OK ){
          rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize,
                              pPager->journalOff + 4);
          pPager->journalOff += pPager->pageSize+4;
        }
        if( rc==SQLITE_OK ){
          rc = write32bits(pPager->jfd, pPager->journalOff, cksum);
          pPager->journalOff += 4;
        }
        IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
                 pPager->journalOff, pPager->pageSize));
        PAGER_INCR(sqlite3_pager_writej_count);
        PAGERTRACE5("JOURNAL %d page %d needSync=%d hash(%08x)\n",
             PAGERID(pPager), pPg->pgno, 
             ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg));

          /* An error has occured writing to the journal file. The 
          ** transaction will be rolled back by the layer above.
          */
          if( rc!=SQLITE_OK ){
            return rc;
          }
        /* An error has occured writing to the journal file. The 
        ** transaction will be rolled back by the layer above.
        */
        if( rc!=SQLITE_OK ){
          return rc;
        }

          pPager->nRec++;
          assert( pPager->pInJournal!=0 );
          sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
          if( !pPager->noSync ){
            pPg->flags |= PGHDR_NEED_SYNC;
          }
          if( pPager->stmtInUse ){
            sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
        pPager->nRec++;
        assert( pPager->pInJournal!=0 );
        sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
        if( !pPager->noSync ){
          pPg->flags |= PGHDR_NEED_SYNC;
        }
        if( pPager->stmtInUse ){
          sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
          }
        }
      }else{
        if( !pPager->journalStarted && !pPager->noSync ){
          pPg->flags |= PGHDR_NEED_SYNC;
        }
        PAGERTRACE4("APPEND %d page %d needSync=%d\n",
                PAGERID(pPager), pPg->pgno,

    ** the statement journal format differs from the standard journal format
    ** in that it omits the checksums and the header.
    */
    if( pPager->stmtInUse 
     && !pageInStatement(pPg) 
     && (int)pPg->pgno<=pPager->stmtSize 
    ){
      assert( (pPg->flags&PGHDR_IN_JOURNAL) 
                 || (int)pPg->pgno>pPager->origDbSize );
      if( MEMDB ){
        rc = sqlite3PcachePreserve(pPg, 1);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        PAGERTRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
      }else{
        i64 offset = pPager->stmtNRec*(4+pPager->pageSize);
        char *pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
        rc = write32bits(pPager->stfd, offset, pPg->pgno);
        if( rc==SQLITE_OK ){
          rc = sqlite3OsWrite(pPager->stfd, pData2, pPager->pageSize, offset+4);
        }
        PAGERTRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        pPager->stmtNRec++;
        assert( pPager->pInStmt!=0 );
        sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
      i64 offset = pPager->stmtNRec*(4+pPager->pageSize);
      char *pData2 = CODEC2(pPager, pData, pPg->pgno, 7);
      assert( (pPg->flags&PGHDR_IN_JOURNAL) 
                 || (int)pPg->pgno>pPager->origDbSize );
      rc = write32bits(pPager->stfd, offset, pPg->pgno);
      if( rc==SQLITE_OK ){
        rc = sqlite3OsWrite(pPager->stfd, pData2, pPager->pageSize, offset+4);
      }
      PAGERTRACE3("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      pPager->stmtNRec++;
      assert( pPager->pInStmt!=0 );
      sqlite3BitvecSet(pPager->pInStmt, pPg->pgno);
      }
    }
  }

  /* Update the database size and return.
  */
  assert( pPager->state>=PAGER_SHARED );
  if( pPager->dbSize<(int)pPg->pgno ){
    pPager->dbSize = pPg->pgno;
    if( !MEMDB && pPager->dbSize==PENDING_BYTE/pPager->pageSize ){
    if( pPager->dbSize==PENDING_BYTE/pPager->pageSize ){
      pPager->dbSize++;
    }
  }
  return rc;
}

/*

SQLITE_PRIVATE int sqlite3PagerWrite(DbPage *pDbPage){
  int rc = SQLITE_OK;

  PgHdr *pPg = pDbPage;
  Pager *pPager = pPg->pPager;
  Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);

  if( !MEMDB && nPagePerSector>1 ){
  if( nPagePerSector>1 ){
    Pgno nPageCount;          /* Total number of pages in database file */
    Pgno pg1;                 /* First page of the sector pPg is located on. */
    int nPage;                /* Number of pages starting at pg1 to journal */
    int ii;
    int needSync = 0;

    /* Set the doNotSync flag to 1. This is because we cannot allow a journal
    ** header to be written between the pages journaled by this function.
    */
    assert( !MEMDB );
    assert( pPager->doNotSync==0 );
    pPager->doNotSync = 1;

    /* This trick assumes that both the page-size and sector-size are
    ** an integer power of 2. It sets variable pg1 to the identifier
    ** of the first page of the sector pPg is located on.
    */

  return pPg->flags&PGHDR_DIRTY;
}
#endif

/*
** A call to this routine tells the pager that it is not necessary to
** write the information on page pPg back to the disk, even though
** that page might be marked as dirty.
** that page might be marked as dirty.  This happens, for example, when
** the page has been added as a leaf of the freelist and so its
** content no longer matters.
**
** The overlying software layer calls this routine when all of the data
** on the given page is unused.  The pager marks the page as clean so
** that it does not get written to disk.
**
** Tests show that this optimization, together with the
** sqlite3PagerDontRollback() below, more than double the speed

** rolled back in spite of the sqlite3PagerDontRollback() call.
*/
SQLITE_PRIVATE int sqlite3PagerDontWrite(DbPage *pDbPage){
  PgHdr *pPg = pDbPage;
  Pager *pPager = pPg->pPager;
  int rc;

  if( MEMDB || pPg->pgno>pPager->origDbSize ){
  if( pPg->pgno>pPager->origDbSize ){
    return SQLITE_OK;
  }
  if( pPager->pAlwaysRollback==0 ){
    assert( pPager->pInJournal );
    pPager->pAlwaysRollback = sqlite3BitvecCreate(pPager->origDbSize);
    if( !pPager->pAlwaysRollback ){
      return SQLITE_NOMEM;

  */
  if( pPager->journalOpen==0 
   || sqlite3BitvecTest(pPager->pAlwaysRollback, pPg->pgno)
   || pPg->pgno>pPager->origDbSize
  ){
    return;
  }
  assert( !MEMDB );    /* For a memdb, pPager->journalOpen is always 0 */

#ifdef SQLITE_SECURE_DELETE
  if( (pPg->flags & PGHDR_IN_JOURNAL)!=0 || (int)pPg->pgno>pPager->origDbSize ){
    return;
  }
#endif

  if( pPager->dbModified==0 &&
        (pPager->journalMode!=PAGER_JOURNALMODE_DELETE ||
          pPager->exclusiveMode!=0) ){
    assert( pPager->dirtyCache==0 || pPager->journalOpen==0 );
    return SQLITE_OK;
  }
  PAGERTRACE2("COMMIT %d\n", PAGERID(pPager));
  if( MEMDB ){
    sqlite3PcacheCommit(pPager->pPCache, 0);
    sqlite3PcacheCleanAll(pPager->pPCache);
    sqlite3PcacheAssertFlags(pPager->pPCache, 0, PGHDR_IN_JOURNAL);
    pPager->state = PAGER_SHARED;
  }else{
    assert( pPager->state==PAGER_SYNCED || !pPager->dirtyCache );
    rc = pager_end_transaction(pPager, pPager->setMaster);
    rc = pager_error(pPager, rc);
  assert( pPager->state==PAGER_SYNCED || MEMDB || !pPager->dirtyCache );
  rc = pager_end_transaction(pPager, pPager->setMaster);
  rc = pager_error(pPager, rc);
  }
  return rc;
}

/*
** Rollback all changes.  The database falls back to PAGER_SHARED mode.
** All in-memory cache pages revert to their original data contents.
** The journal is deleted.
**
** This routine cannot fail unless some other process is not following
** the correct locking protocol or unless some other
** process is writing trash into the journal file (SQLITE_CORRUPT) or
** unless a prior malloc() failed (SQLITE_NOMEM).  Appropriate error
** codes are returned for all these occasions.  Otherwise,
** SQLITE_OK is returned.
*/
SQLITE_PRIVATE int sqlite3PagerRollback(Pager *pPager){
  int rc = SQLITE_OK;
  PAGERTRACE2("ROLLBACK %d\n", PAGERID(pPager));
  if( MEMDB ){
    sqlite3PcacheRollback(pPager->pPCache, 1, pPager->xReiniter);
    sqlite3PcacheRollback(pPager->pPCache, 0, pPager->xReiniter);
    sqlite3PcacheCleanAll(pPager->pPCache);
    sqlite3PcacheAssertFlags(pPager->pPCache, 0, PGHDR_IN_JOURNAL);
    pPager->dbSize = pPager->origDbSize;
    pager_truncate_cache(pPager);
    pPager->stmtInUse = 0;
    pPager->state = PAGER_SHARED;
  }else if( !pPager->dirtyCache || !pPager->journalOpen ){
  if( !pPager->dirtyCache || !pPager->journalOpen ){
    rc = pager_end_transaction(pPager, pPager->setMaster);
  }else if( pPager->errCode && pPager->errCode!=SQLITE_FULL ){
    if( pPager->state>=PAGER_EXCLUSIVE ){
      pager_playback(pPager, 0);
    }
    rc = pPager->errCode;
  }else{
    if( pPager->state==PAGER_RESERVED ){
      int rc2;
      rc = pager_playback(pPager, 0);
      rc2 = pager_end_transaction(pPager, pPager->setMaster);
      if( rc==SQLITE_OK ){
        rc = rc2;
      }
    }else{
      rc = pager_playback(pPager, 0);
    }

    if( !MEMDB ){
    pPager->dbSize = -1;
      pPager->dbSize = -1;
    }

    /* If an error occurs during a ROLLBACK, we can no longer trust the pager
    ** cache. So call pager_error() on the way out to make any error 
    ** persistent.
    */
    rc = pager_error(pPager, rc);
  }

/*
** Return the number of references to the pager.
*/
SQLITE_PRIVATE int sqlite3PagerRefcount(Pager *pPager){
  return sqlite3PcacheRefCount(pPager->pPCache);
}

/*
** Return the number of references to the specified page.
*/
SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage *pPage){
  return sqlite3PcachePageRefcount(pPage);
}

#ifdef SQLITE_TEST
/*
** This routine is used for testing and analysis only.
*/
SQLITE_PRIVATE int *sqlite3PagerStats(Pager *pPager){
  static int a[11];

*/
static int pagerStmtBegin(Pager *pPager){
  int rc;
  assert( !pPager->stmtInUse );
  assert( pPager->state>=PAGER_SHARED );
  assert( pPager->dbSize>=0 );
  PAGERTRACE2("STMT-BEGIN %d\n", PAGERID(pPager));
  if( MEMDB ){
    pPager->stmtInUse = 1;
    pPager->stmtSize = pPager->dbSize;
    return SQLITE_OK;
  }
  if( !pPager->journalOpen ){
    pPager->stmtAutoopen = 1;
    return SQLITE_OK;
  }
  assert( pPager->journalOpen );
  assert( pPager->pInStmt==0 );
  pPager->pInStmt = sqlite3BitvecCreate(pPager->dbSize);
  if( pPager->pInStmt==0 ){
    /* sqlite3OsLock(pPager->fd, SHARED_LOCK); */
    return SQLITE_NOMEM;
  }
  pPager->stmtJSize = pPager->journalOff;
  pPager->stmtSize = pPager->dbSize;
  pPager->stmtHdrOff = 0;
  pPager->stmtCksum = pPager->cksumInit;
  if( !pPager->stmtOpen ){
    if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
      sqlite3MemJournalOpen(pPager->stfd);
    }else{
    rc = sqlite3PagerOpentemp(pPager, pPager->stfd, SQLITE_OPEN_SUBJOURNAL);
    if( rc ){
      goto stmt_begin_failed;
      rc = sqlite3PagerOpentemp(pPager, pPager->stfd, SQLITE_OPEN_SUBJOURNAL);
      if( rc ){
        goto stmt_begin_failed;
      }
    }
    pPager->stmtOpen = 1;
    pPager->stmtNRec = 0;
  }
  pPager->stmtInUse = 1;
  return SQLITE_OK;
 

/*
** Commit a statement.
*/
SQLITE_PRIVATE int sqlite3PagerStmtCommit(Pager *pPager){
  if( pPager->stmtInUse ){
    PAGERTRACE2("STMT-COMMIT %d\n", PAGERID(pPager));
    if( !MEMDB ){
      sqlite3BitvecDestroy(pPager->pInStmt);
      pPager->pInStmt = 0;
    sqlite3BitvecDestroy(pPager->pInStmt);
    pPager->pInStmt = 0;
    }else{
      sqlite3PcacheCommit(pPager->pPCache, 1);
    }
    pPager->stmtNRec = 0;
    pPager->stmtInUse = 0;
    if( sqlite3IsMemJournal(pPager->stfd) ){
      sqlite3OsTruncate(pPager->stfd, 0);
    }
  }
  pPager->stmtAutoopen = 0;
  return SQLITE_OK;
}

/*
** Rollback a statement.
*/
SQLITE_PRIVATE int sqlite3PagerStmtRollback(Pager *pPager){
  int rc;
  if( pPager->stmtInUse ){
    PAGERTRACE2("STMT-ROLLBACK %d\n", PAGERID(pPager));
    if( MEMDB ){
      sqlite3PcacheRollback(pPager->pPCache, 1, pPager->xReiniter);
      pPager->dbSize = pPager->stmtSize;
      pager_truncate_cache(pPager);
      rc = SQLITE_OK;
    }else{
      rc = pager_stmt_playback(pPager);
    rc = pager_stmt_playback(pPager);
    }
    sqlite3PagerStmtCommit(pPager);
  }else{
    rc = SQLITE_OK;
  }
  pPager->stmtAutoopen = 0;
  return rc;
}

  pPg->flags &= ~(PGHDR_NEED_SYNC|PGHDR_IN_JOURNAL);
  pPgOld = pager_lookup(pPager, pgno);
  assert( !pPgOld || pPgOld->nRef==1 );
  if( pPgOld ){
    pPg->flags |= (pPgOld->flags&PGHDR_NEED_SYNC);
  }
  if( sqlite3BitvecTest(pPager->pInJournal, pgno) ){
    assert( !MEMDB );
    pPg->flags |= PGHDR_IN_JOURNAL;
  }

  sqlite3PcacheMove(pPg, pgno);
  if( pPgOld ){
    sqlite3PcacheMove(pPgOld, 0);
    sqlite3PcacheRelease(pPgOld);

}
#endif

/*
** Return a pointer to the data for the specified page.
*/
SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *pPg){
  assert( pPg->nRef>0 );
  assert( pPg->nRef>0 || pPg->pPager->memDb );
  return pPg->pData;
}

/*
** Return a pointer to the Pager.nExtra bytes of "extra" space 
** allocated along with the specified page.
*/

  if( eMode>=0 && !pPager->tempFile ){
    pPager->exclusiveMode = eMode;
  }
  return (int)pPager->exclusiveMode;
}

/*
** Get/set the journal-mode for this pager. Parameter eMode must be one
** of PAGER_JOURNALMODE_QUERY, PAGER_JOURNALMODE_DELETE or 
** PAGER_JOURNALMODE_PERSIST. If the parameter is not _QUERY, then
** the journal-mode is set to the value specified.
** Get/set the journal-mode for this pager. Parameter eMode must be one of:
**
**    PAGER_JOURNALMODE_QUERY
**    PAGER_JOURNALMODE_DELETE
**    PAGER_JOURNALMODE_TRUNCATE
**    PAGER_JOURNALMODE_PERSIST
**    PAGER_JOURNALMODE_OFF
**
** If the parameter is not _QUERY, then the journal-mode is set to the
** value specified.
**
** The returned value is either PAGER_JOURNALMODE_DELETE or
** PAGER_JOURNALMODE_PERSIST, indicating the current (possibly updated)
** The returned indicate the current (possibly updated)
** journal-mode.
*/
SQLITE_PRIVATE int sqlite3PagerJournalMode(Pager *pPager, int eMode){
  if( !MEMDB ){
  assert( eMode==PAGER_JOURNALMODE_QUERY
            || eMode==PAGER_JOURNALMODE_DELETE
            || eMode==PAGER_JOURNALMODE_PERSIST
            || eMode==PAGER_JOURNALMODE_OFF );
  assert( PAGER_JOURNALMODE_QUERY<0 );
  assert( PAGER_JOURNALMODE_DELETE>=0 && PAGER_JOURNALMODE_PERSIST>=0 );
  if( eMode>=0 ){
    pPager->journalMode = eMode;
    assert( eMode==PAGER_JOURNALMODE_QUERY
              || eMode==PAGER_JOURNALMODE_DELETE
              || eMode==PAGER_JOURNALMODE_TRUNCATE
              || eMode==PAGER_JOURNALMODE_PERSIST
              || eMode==PAGER_JOURNALMODE_OFF 
              || eMode==PAGER_JOURNALMODE_MEMORY );
    assert( PAGER_JOURNALMODE_QUERY<0 );
    if( eMode>=0 ){
      pPager->journalMode = eMode;
    }else{
      assert( eMode==PAGER_JOURNALMODE_QUERY );
    }
  }
  return (int)pPager->journalMode;
}

/*
** Get/set the size-limit used for persistent journal files.
*/

**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** $Id: btmutex.c,v 1.10 2008/07/14 19:39:17 drh Exp $
** $Id: btmutex.c,v 1.11 2008/10/07 15:25:48 drh Exp $
**
** This file contains code used to implement mutexes on Btree objects.
** This code really belongs in btree.c.  But btree.c is getting too
** big and we want to break it down some.  This packaged seemed like
** a good breakout.
*/
/************** Include btreeInt.h in the middle of btmutex.c ****************/
/************** Begin file btreeInt.h ****************************************/
/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btreeInt.h,v 1.31 2008/09/18 17:34:44 danielk1977 Exp $
** $Id: btreeInt.h,v 1.34 2008/09/30 17:18:17 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

** The pageDestructor() routine handles that chore.
**
** Access to all fields of this structure is controlled by the mutex
** stored in MemPage.pBt->mutex.
*/
struct MemPage {
  u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
  u8 idxShift;         /* True if Cell indices have changed */
  u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
  u8 intKey;           /* True if intkey flag is set */
  u8 leaf;             /* True if leaf flag is set */
  u8 hasData;          /* True if this page stores data */
  u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
  u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
  u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */
  u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */
  u16 cellOffset;      /* Index in aData of first cell pointer */
  u16 idxParent;       /* Index in parent of this node */
  u16 nFree;           /* Number of free bytes on the page */
  u16 nCell;           /* Number of cells on this page, local and ovfl */
  u16 maskPage;        /* Mask for page offset */
  struct _OvflCell {   /* Cells that will not fit on aData[] */
    u8 *pCell;          /* Pointers to the body of the overflow cell */
    u16 idx;            /* Insert this cell before idx-th non-overflow cell */
  } aOvfl[5];
  BtShared *pBt;       /* Pointer to BtShared that this page is part of */
  u8 *aData;           /* Pointer to disk image of the page data */
  DbPage *pDbPage;     /* Pager page handle */
  Pgno pgno;           /* Page number for this page */
  MemPage *pParent;    /* The parent of this page.  NULL for root */
};

/*
** Possible values for the MemPage.isInit variable. When a page is first
** loaded or if the data stored in the MemPage struct is invalidated, 
** MemPage.isInit is set to PAGE_ISINIT_NONE. If the MemPage structure
** is fully initialized, then MemPage.isInit is set to PAGE_ISINIT_FULL.
** MemPage.isInit is set to PAGE_ISINIT_DATA when the MemPage struct is
** populated, but the MemPage.pParent variable is not necessarily correct.
*/
#define PAGE_ISINIT_NONE 0
#define PAGE_ISINIT_DATA 1
#define PAGE_ISINIT_FULL 2

/*
** The in-memory image of a disk page has the auxiliary information appended
** to the end.  EXTRA_SIZE is the number of bytes of space needed to hold
** that extra information.
*/
#define EXTRA_SIZE sizeof(MemPage)

  u32 nPayload;  /* Total amount of payload */
  u16 nHeader;   /* Size of the cell content header in bytes */
  u16 nLocal;    /* Amount of payload held locally */
  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
  u16 nSize;     /* Size of the cell content on the main b-tree page */
};

/*
** Maximum depth of an SQLite B-Tree structure. Any B-Tree deeper than
** this will be declared corrupt. This value is calculated based on a
** maximum database size of 2^31 pages a minimum fanout of 2 for a
** root-node and 3 for all other internal nodes.
**
** If a tree that appears to be taller than this is encountered, it is
** assumed that the database is corrupt.
*/
#define BTCURSOR_MAX_DEPTH 20

/*
** A cursor is a pointer to a particular entry within a particular
** b-tree within a database file.
**
** The entry is identified by its MemPage and the index in
** MemPage.aCell[] of the entry.
**
** When a single database file can shared by two more database connections,
** but cursors cannot be shared.  Each cursor is associated with a
** particular database connection identified BtCursor.pBtree.db.
**
** Fields in this structure are accessed under the BtShared.mutex
** found at self->pBt->mutex. 
*/
struct BtCursor {
  Btree *pBtree;            /* The Btree to which this cursor belongs */
  BtShared *pBt;            /* The BtShared this cursor points to */
  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
  Pgno pgnoRoot;            /* The root page of this tree */
  MemPage *pPage;           /* Page that contains the entry */
  int idx;                  /* Index of the entry in pPage->aCell[] */
  CellInfo info;            /* A parse of the cell we are pointing at */
  u8 wrFlag;                /* True if writable */
  u8 atLast;                /* Cursor pointing to the last entry */
  u8 validNKey;             /* True if info.nKey is valid */
  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
  void *pKey;      /* Saved key that was cursor's last known position */
  i64 nKey;        /* Size of pKey, or last integer key */
  int skip;        /* (skip<0) -> Prev() is a no-op. (skip>0) -> Next() is */
#ifndef SQLITE_OMIT_INCRBLOB
  u8 isIncrblobHandle;      /* True if this cursor is an incr. io handle */
  Pgno *aOverflow;          /* Cache of overflow page locations */
#endif
#ifndef NDEBUG
  u8 pagesShuffled;         /* True if Btree pages are rearranged by balance()*/
#endif
  i16 iPage;                            /* Index of current page in apPage */
  MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
  u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
};

/*
** Potential values for BtCursor.eState.
**
** CURSOR_VALID:
**   Cursor points to a valid entry. getPayload() etc. may be called.

#define get4byte sqlite3Get4byte
#define put4byte sqlite3Put4byte

/*
** Internal routines that should be accessed by the btree layer only.
*/
SQLITE_PRIVATE int sqlite3BtreeGetPage(BtShared*, Pgno, MemPage**, int);
SQLITE_PRIVATE int sqlite3BtreeInitPage(MemPage *pPage, MemPage *pParent);
SQLITE_PRIVATE int sqlite3BtreeInitPage(MemPage *pPage);
SQLITE_PRIVATE void sqlite3BtreeParseCellPtr(MemPage*, u8*, CellInfo*);
SQLITE_PRIVATE void sqlite3BtreeParseCell(MemPage*, int, CellInfo*);
SQLITE_PRIVATE int sqlite3BtreeRestoreCursorPosition(BtCursor *pCur);
SQLITE_PRIVATE void sqlite3BtreeGetTempCursor(BtCursor *pCur, BtCursor *pTempCur);
SQLITE_PRIVATE void sqlite3BtreeReleaseTempCursor(BtCursor *pCur);
SQLITE_PRIVATE int sqlite3BtreeIsRootPage(MemPage *pPage);
SQLITE_PRIVATE void sqlite3BtreeMoveToParent(BtCursor *pCur);

/************** End of btreeInt.h ********************************************/
/************** Continuing where we left off in btmutex.c ********************/
#if SQLITE_THREADSAFE && !defined(SQLITE_OMIT_SHARED_CACHE)

  /* We should already hold a lock on the database connection */
  assert( sqlite3_mutex_held(p->db->mutex) );

  if( !p->sharable ) return;
  p->wantToLock++;
  if( p->locked ) return;

#ifndef SQLITE_MUTEX_NOOP
  /* In most cases, we should be able to acquire the lock we
  ** want without having to go throught the ascending lock
  ** procedure that follows.  Just be sure not to block.
  */
  if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){
    p->locked = 1;
    return;

  p->locked = 1;
  for(pLater=p->pNext; pLater; pLater=pLater->pNext){
    if( pLater->wantToLock ){
      sqlite3_mutex_enter(pLater->pBt->mutex);
      pLater->locked = 1;
    }
  }
#endif /* SQLITE_MUTEX_NOOP */
}

/*
** Exit the recursive mutex on a Btree.
*/
SQLITE_PRIVATE void sqlite3BtreeLeave(Btree *p){
  if( p->sharable ){

** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.516 2008/09/19 16:39:38 danielk1977 Exp $
** $Id: btree.c,v 1.533 2008/11/12 08:49:52 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/

/*

#if 0
int sqlite3BtreeTrace=0;  /* True to enable tracing */
# define TRACE(X)  if(sqlite3BtreeTrace){printf X;fflush(stdout);}
#else
# define TRACE(X)
#endif

/*
** Sometimes we need a small amount of code such as a variable initialization
** to setup for a later assert() statement.  We do not want this code to
** appear when assert() is disabled.  The following macro is therefore
** used to contain that setup code.  The "VVA" acronym stands for
** "Verification, Validation, and Accreditation".  In other words, the
** code within VVA_ONLY() will only run during verification processes.
*/
#ifndef NDEBUG
# define VVA_ONLY(X)  X
#else
# define VVA_ONLY(X)
#endif



#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** A list of BtShared objects that are eligible for participation
** in shared cache.  This variable has file scope during normal builds,
** but the test harness needs to access it so we make it global for 

  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.
  */
  if( rc==SQLITE_OK && 0==pCur->pPage->intKey){
  if( rc==SQLITE_OK && 0==pCur->apPage[0]->intKey){
    void *pKey = sqlite3Malloc(pCur->nKey);
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }
    }else{
      rc = SQLITE_NOMEM;
    }
  }
  assert( !pCur->pPage->intKey || !pCur->pKey );
  assert( !pCur->apPage[0]->intKey || !pCur->pKey );

  if( rc==SQLITE_OK ){
    int i;
    for(i=0; i<=pCur->iPage; i++){
    releasePage(pCur->pPage);
    pCur->pPage = 0;
      releasePage(pCur->apPage[i]);
      pCur->apPage[i] = 0;
    }
    pCur->iPage = -1;
    pCur->eState = CURSOR_REQUIRESEEK;
  }

  invalidateOverflowCache(pCur);
  return rc;
}

  }
  return SQLITE_OK;
}

/*
** Clear the current cursor position.
*/
static void clearCursorPosition(BtCursor *pCur){
SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *pCur){
  assert( cursorHoldsMutex(pCur) );
  sqlite3_free(pCur->pKey);
  pCur->pKey = 0;
  pCur->eState = CURSOR_INVALID;
}

/*

#define restoreCursorPosition(p) \
  (p->eState>=CURSOR_REQUIRESEEK ? \
         sqlite3BtreeRestoreCursorPosition(p) : \
         SQLITE_OK)

/*
** Determine whether or not a cursor has moved from the position it
** was last placed at.  Cursor can move when the row they are pointing
** was last placed at.  Cursors can move when the row they are pointing
** at is deleted out from under them.
**
** This routine returns an error code if something goes wrong.  The
** integer *pHasMoved is set to one if the cursor has moved and 0 if not.
*/
SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor *pCur, int *pHasMoved){
  int rc;

/*
** Defragment the page given.  All Cells are moved to the
** end of the page and all free space is collected into one
** big FreeBlk that occurs in between the header and cell
** pointer array and the cell content area.
*/
static void defragmentPage(MemPage *pPage){
static int defragmentPage(MemPage *pPage){
  int i;                     /* Loop counter */
  int pc;                    /* Address of a i-th cell */
  int addr;                  /* Offset of first byte after cell pointer array */
  int hdr;                   /* Offset to the page header */
  int size;                  /* Size of a cell */
  int usableSize;            /* Number of usable bytes on a page */
  int cellOffset;            /* Offset to the cell pointer array */

  cbrk = get2byte(&data[hdr+5]);
  memcpy(&temp[cbrk], &data[cbrk], usableSize - cbrk);
  cbrk = usableSize;
  for(i=0; i<nCell; i++){
    u8 *pAddr;     /* The i-th cell pointer */
    pAddr = &data[cellOffset + i*2];
    pc = get2byte(pAddr);
    assert( pc<pPage->pBt->usableSize );
    if (pc >= pPage->pBt->usableSize) {
      return SQLITE_CORRUPT_BKPT;
    }
    size = cellSizePtr(pPage, &temp[pc]);
    cbrk -= size;
    if ((cbrk < cellOffset+2*nCell) || (cbrk+size>pPage->pBt->usableSize)) {
      return SQLITE_CORRUPT_BKPT;
    }
    memcpy(&data[cbrk], &temp[pc], size);
    put2byte(pAddr, cbrk);
  }
  assert( cbrk>=cellOffset+2*nCell );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  data[hdr+7] = 0;
  addr = cellOffset+2*nCell;
  memset(&data[addr], 0, cbrk-addr);
  if( cbrk-addr!=pPage->nFree ){
    return SQLITE_CORRUPT_BKPT;
  }
  return SQLITE_OK;
}

/*
** Allocate nByte bytes of space on a page.
**
** Return the index into pPage->aData[] of the first byte of
** the new allocation.  The caller guarantees that there is enough

  }
  return SQLITE_OK;
}

/*
** Initialize the auxiliary information for a disk block.
**
** The pParent parameter must be a pointer to the MemPage which
** is the parent of the page being initialized.  The root of a
** BTree has no parent and so for that page, pParent==NULL.
**
** Return SQLITE_OK on success.  If we see that the page does
** not contain a well-formed database page, then return 
** SQLITE_CORRUPT.  Note that a return of SQLITE_OK does not
** guarantee that the page is well-formed.  It only shows that
** we failed to detect any corruption.
*/
SQLITE_PRIVATE int sqlite3BtreeInitPage(
  MemPage *pPage,        /* The page to be initialized */
  MemPage *pParent       /* The parent.  Might be NULL */
){
  int pc;            /* Address of a freeblock within pPage->aData[] */
  int hdr;           /* Offset to beginning of page header */
  u8 *data;          /* Equal to pPage->aData */
  BtShared *pBt;        /* The main btree structure */
  int usableSize;    /* Amount of usable space on each page */
  int cellOffset;    /* Offset from start of page to first cell pointer */
  int nFree;         /* Number of unused bytes on the page */
  int top;           /* First byte of the cell content area */
SQLITE_PRIVATE int sqlite3BtreeInitPage(MemPage *pPage){

  assert( pPage->pBt!=0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
  assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
  assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );

  if( !pPage->isInit ){
    int pc;            /* Address of a freeblock within pPage->aData[] */
    int hdr;           /* Offset to beginning of page header */
    u8 *data;          /* Equal to pPage->aData */
    BtShared *pBt;        /* The main btree structure */
    int usableSize;    /* Amount of usable space on each page */
    int cellOffset;    /* Offset from start of page to first cell pointer */
    int nFree;         /* Number of unused bytes on the page */
    int top;           /* First byte of the cell content area */

  pBt = pPage->pBt;
    pBt = pPage->pBt;
  assert( pBt!=0 );
  assert( pParent==0 || pParent->pBt==pBt );
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
  assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
  assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );
  if( pPage==pParent ){
    return SQLITE_CORRUPT_BKPT;
  }

  if( (pPage->pParent!=pParent)
   && (pPage->pParent!=0 || pPage->isInit==PAGE_ISINIT_FULL) ){
    /* The parent page should never change unless the file is corrupt */
    return SQLITE_CORRUPT_BKPT;
  }
  if( pPage->isInit==PAGE_ISINIT_FULL ) return SQLITE_OK;
  if( pParent!=0 ){
    pPage->pParent = pParent;
    sqlite3PagerRef(pParent->pDbPage);
  }
  if( pPage->isInit==PAGE_ISINIT_NONE ){
    hdr = pPage->hdrOffset;
    data = pPage->aData;
    if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
    assert( pBt->pageSize>=512 && pBt->pageSize<=32768 );
    pPage->maskPage = pBt->pageSize - 1;
    pPage->nOverflow = 0;
    pPage->idxShift = 0;
    usableSize = pBt->usableSize;
    pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
    top = get2byte(&data[hdr+5]);
    pPage->nCell = get2byte(&data[hdr+3]);
    if( pPage->nCell>MX_CELL(pBt) ){
      /* To many cells for a single page.  The page must be corrupt */
      return SQLITE_CORRUPT_BKPT;
    }
    if( pPage->nCell==0 && pParent!=0 && pParent->pgno!=1 ){
      /* All pages must have at least one cell, except for root pages */
      return SQLITE_CORRUPT_BKPT;
    }
  
    /* Compute the total free space on the page */
    pc = get2byte(&data[hdr+1]);
    nFree = data[hdr+7] + top - (cellOffset + 2*pPage->nCell);
    while( pc>0 ){
      int next, size;
      if( pc>usableSize-4 ){

      pc = next;
    }
    pPage->nFree = nFree;
    if( nFree>=usableSize ){
      /* Free space cannot exceed total page size */
      return SQLITE_CORRUPT_BKPT; 
    }
  }

#if 0
  /* Check that all the offsets in the cell offset array are within range. 
  ** 
  ** Omitting this consistency check and using the pPage->maskPage mask
  ** to prevent overrunning the page buffer in findCell() results in a
  ** 2.5% performance gain.

    for(pOff=&data[cellOffset]; pOff!=pEnd && !((*pOff)&mask); pOff+=2);
    if( pOff!=pEnd ){
      return SQLITE_CORRUPT_BKPT;
    }
  }
#endif

  pPage->isInit = PAGE_ISINIT_FULL;
    pPage->isInit = 1;
  }
  return SQLITE_OK;
}

/*
** Set up a raw page so that it looks like a database page holding
** no entries.
*/

  pPage->nFree = pBt->usableSize - first;
  decodeFlags(pPage, flags);
  pPage->hdrOffset = hdr;
  pPage->cellOffset = first;
  pPage->nOverflow = 0;
  assert( pBt->pageSize>=512 && pBt->pageSize<=32768 );
  pPage->maskPage = pBt->pageSize - 1;
  pPage->idxShift = 0;
  pPage->nCell = 0;
  pPage->isInit = PAGE_ISINIT_FULL;
  pPage->isInit = 1;
}


/*
** Convert a DbPage obtained from the pager into a MemPage used by
** the btree layer.
*/

** Get a page from the pager and initialize it.  This routine
** is just a convenience wrapper around separate calls to
** sqlite3BtreeGetPage() and sqlite3BtreeInitPage().
*/
static int getAndInitPage(
  BtShared *pBt,          /* The database file */
  Pgno pgno,           /* Number of the page to get */
  MemPage **ppPage,    /* Write the page pointer here */
  MemPage **ppPage     /* Write the page pointer here */
  MemPage *pParent     /* Parent of the page */
){
  int rc;
  DbPage *pDbPage;
  MemPage *pPage;

  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( !pParent || pParent->isInit==PAGE_ISINIT_FULL );
  if( pgno==0 ){
    return SQLITE_CORRUPT_BKPT; 
  }

  /* It is often the case that the page we want is already in cache.
  ** If so, get it directly.  This saves us from having to call
  ** pagerPagecount() to make sure pgno is within limits, which results

    if( pgno>pagerPagecount(pBt->pPager) ){
      return SQLITE_CORRUPT_BKPT; 
    }
    rc = sqlite3BtreeGetPage(pBt, pgno, ppPage, 0);
    if( rc ) return rc;
    pPage = *ppPage;
  }
  if( pPage->isInit!=PAGE_ISINIT_FULL ){
    rc = sqlite3BtreeInitPage(pPage, pParent);
  if( !pPage->isInit ){
    rc = sqlite3BtreeInitPage(pPage);
  }else if( pParent && (pPage==pParent || pPage->pParent!=pParent) ){
    /* This condition indicates a loop in the b-tree structure (the scenario
    ** where database corruption has caused a page to be a direct or
    ** indirect descendant of itself).
    */ 
    rc = SQLITE_CORRUPT_BKPT;
  }
  if( rc!=SQLITE_OK ){
    releasePage(pPage);
    *ppPage = 0;
  }
  return rc;
}

    assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
    assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
    sqlite3PagerUnref(pPage->pDbPage);
  }
}

/*
** This routine is called when the reference count for a page
** reaches zero.  We need to unref the pParent pointer when that
** happens.
*/
static void pageDestructor(DbPage *pData){
  MemPage *pPage;
  pPage = (MemPage *)sqlite3PagerGetExtra(pData);
  if( pPage ){
    assert( pPage->isInit!=PAGE_ISINIT_FULL 
         || sqlite3_mutex_held(pPage->pBt->mutex) 
    );
    if( pPage->pParent ){
      MemPage *pParent = pPage->pParent;
      assert( pParent->pBt==pPage->pBt );
      pPage->pParent = 0;
      releasePage(pParent);
    }
    if( pPage->isInit==PAGE_ISINIT_FULL ){
      pPage->isInit = PAGE_ISINIT_DATA;
    }
  }
}

/*
** During a rollback, when the pager reloads information into the cache
** so that the cache is restored to its original state at the start of
** the transaction, for each page restored this routine is called.
**
** This routine needs to reset the extra data section at the end of the
** page to agree with the restored data.
*/
static void pageReinit(DbPage *pData){
  MemPage *pPage;
  pPage = (MemPage *)sqlite3PagerGetExtra(pData);
  if( pPage->isInit==PAGE_ISINIT_FULL ){
  if( pPage->isInit ){
    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
    pPage->isInit = 0;
    if( sqlite3PagerPageRefcount(pData)>0 ){
    sqlite3BtreeInitPage(pPage, pPage->pParent);
      sqlite3BtreeInitPage(pPage);
  }else if( pPage->isInit==PAGE_ISINIT_DATA ){
    pPage->isInit = 0;
    }
  }
}

/*
** Invoke the busy handler for a btree.
*/
static int sqlite3BtreeInvokeBusyHandler(void *pArg, int n){

    pBt = sqlite3MallocZero( sizeof(*pBt) );
    if( pBt==0 ){
      rc = SQLITE_NOMEM;
      goto btree_open_out;
    }
    pBt->busyHdr.xFunc = sqlite3BtreeInvokeBusyHandler;
    pBt->busyHdr.pArg = pBt;
    rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename, pageDestructor,
    rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
                          EXTRA_SIZE, flags, vfsFlags);
    if( rc==SQLITE_OK ){
      rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
    }
    if( rc!=SQLITE_OK ){
      goto btree_open_out;
    }

trans_begun:
  btreeIntegrity(p);
  sqlite3BtreeLeave(p);
  return rc;
}


#ifndef SQLITE_OMIT_AUTOVACUUM

/*
** Set the pointer-map entries for all children of page pPage. Also, if
** pPage contains cells that point to overflow pages, set the pointer
** map entries for the overflow pages as well.
*/
static int setChildPtrmaps(MemPage *pPage){
  int i;                             /* Counter variable */
  int nCell;                         /* Number of cells in page pPage */
  int rc;                            /* Return code */
  BtShared *pBt = pPage->pBt;
  int isInitOrig = pPage->isInit;
  Pgno pgno = pPage->pgno;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  rc = sqlite3BtreeInitPage(pPage, pPage->pParent);
  rc = sqlite3BtreeInitPage(pPage);
  if( rc!=SQLITE_OK ){
    goto set_child_ptrmaps_out;
  }
  nCell = pPage->nCell;

  for(i=0; i<nCell; i++){
    u8 *pCell = findCell(pPage, i);

    rc = ptrmapPutOvflPtr(pPage, pCell);
    if( rc!=SQLITE_OK ){
      goto set_child_ptrmaps_out;
    }

    if( !pPage->leaf ){
      Pgno childPgno = get4byte(pCell);
      rc = ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno);
       if( rc!=SQLITE_OK ) goto set_child_ptrmaps_out;
      if( rc!=SQLITE_OK ) goto set_child_ptrmaps_out;
    }
  }

  if( !pPage->leaf ){
    Pgno childPgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
    rc = ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno);
  }

    }
    put4byte(pPage->aData, iTo);
  }else{
    int isInitOrig = pPage->isInit;
    int i;
    int nCell;

    sqlite3BtreeInitPage(pPage, 0);
    sqlite3BtreeInitPage(pPage);
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
      u8 *pCell = findCell(pPage, i);
      if( eType==PTRMAP_OVERFLOW1 ){
        CellInfo info;
        sqlite3BtreeParseCellPtr(pPage, pCell, &info);

** the database file should be truncated to during the commit process. 
** i.e. the database has been reorganized so that only the first *pnTrunc
** pages are in use.
*/
static int autoVacuumCommit(BtShared *pBt, Pgno *pnTrunc){
  int rc = SQLITE_OK;
  Pager *pPager = pBt->pPager;
#ifndef NDEBUG
  int nRef = sqlite3PagerRefcount(pPager);
  VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager) );
#endif

  assert( sqlite3_mutex_held(pBt->mutex) );
  invalidateAllOverflowCache(pBt);
  assert(pBt->autoVacuum);
  if( !pBt->incrVacuum ){
    Pgno nFin = 0;

    *pnTrunc = pBt->nTrunc;
    pBt->nTrunc = 0;
  }
  assert( nRef==sqlite3PagerRefcount(pPager) );
  return rc;
}

#endif
#endif /* ifndef SQLITE_OMIT_AUTOVACUUM */

/*
** This routine does the first phase of a two-phase commit.  This routine
** causes a rollback journal to be created (if it does not already exist)
** and populated with enough information so that if a power loss occurs
** the database can be restored to its original state by playing back
** the journal.  Then the contents of the journal are flushed out to

** save the state of the cursor.  The cursor must be
** invalidated.
*/
SQLITE_PRIVATE void sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode){
  BtCursor *p;
  sqlite3BtreeEnter(pBtree);
  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
    clearCursorPosition(p);
    sqlite3BtreeClearCursor(p);
    p->eState = CURSOR_FAULT;
    p->skip = errCode;
  }
  sqlite3BtreeLeave(pBtree);
}

/*

** 3:  The database must be writable (not on read-only media)
**
** 4:  There must be an active transaction.
**
** No checking is done to make sure that page iTable really is the
** root page of a b-tree.  If it is not, then the cursor acquired
** will not work correctly.
**
** It is assumed that the sqlite3BtreeCursorSize() bytes of memory 
** pointed to by pCur have been zeroed by the caller.
*/
static int btreeCursor(
  Btree *p,                              /* The btree */
  int iTable,                            /* Root page of table to open */
  int wrFlag,                            /* 1 to write. 0 read-only */
  struct KeyInfo *pKeyInfo,              /* First arg to comparison function */
  BtCursor *pCur                         /* Space for new cursor */

    }
  }
  pCur->pgnoRoot = (Pgno)iTable;
  if( iTable==1 && pagerPagecount(pBt->pPager)==0 ){
    rc = SQLITE_EMPTY;
    goto create_cursor_exception;
  }
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]);
  if( rc!=SQLITE_OK ){
    goto create_cursor_exception;
  }

  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables, link the cursor into the BtShared list and set *ppCur (the
  ** output argument to this function).

  }
  pBt->pCursor = pCur;
  pCur->eState = CURSOR_INVALID;

  return SQLITE_OK;

create_cursor_exception:
  releasePage(pCur->pPage);
  releasePage(pCur->apPage[0]);
  unlockBtreeIfUnused(pBt);
  return rc;
}
SQLITE_PRIVATE int sqlite3BtreeCursor(
  Btree *p,                                   /* The btree */
  int iTable,                                 /* Root page of table to open */
  int wrFlag,                                 /* 1 to write. 0 read-only */

/*
** Close a cursor.  The read lock on the database file is released
** when the last cursor is closed.
*/
SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
  Btree *pBtree = pCur->pBtree;
  if( pBtree ){
    int i;
    BtShared *pBt = pCur->pBt;
    sqlite3BtreeEnter(pBtree);
    pBt->db = pBtree->db;
    clearCursorPosition(pCur);
    sqlite3BtreeClearCursor(pCur);
    if( pCur->pPrev ){
      pCur->pPrev->pNext = pCur->pNext;
    }else{
      pBt->pCursor = pCur->pNext;
    }
    if( pCur->pNext ){
      pCur->pNext->pPrev = pCur->pPrev;
    }
    for(i=0; i<=pCur->iPage; i++){
    releasePage(pCur->pPage);
      releasePage(pCur->apPage[i]);
    }
    unlockBtreeIfUnused(pBt);
    invalidateOverflowCache(pCur);
    /* sqlite3_free(pCur); */
    sqlite3BtreeLeave(pBtree);
  }
  return SQLITE_OK;
}

/*
** Make a temporary cursor by filling in the fields of pTempCur.
** The temporary cursor is not on the cursor list for the Btree.
*/
SQLITE_PRIVATE void sqlite3BtreeGetTempCursor(BtCursor *pCur, BtCursor *pTempCur){
  int i;
  assert( cursorHoldsMutex(pCur) );
  memcpy(pTempCur, pCur, sizeof(*pCur));
  memcpy(pTempCur, pCur, sizeof(BtCursor));
  pTempCur->pNext = 0;
  pTempCur->pPrev = 0;
  if( pTempCur->pPage ){
    sqlite3PagerRef(pTempCur->pPage->pDbPage);
  for(i=0; i<=pTempCur->iPage; i++){
    sqlite3PagerRef(pTempCur->apPage[i]->pDbPage);
  }
}

/*
** Delete a temporary cursor such as was made by the CreateTemporaryCursor()
** function above.
*/
SQLITE_PRIVATE void sqlite3BtreeReleaseTempCursor(BtCursor *pCur){
  int i;
  assert( cursorHoldsMutex(pCur) );
  if( pCur->pPage ){
    sqlite3PagerUnref(pCur->pPage->pDbPage);
  for(i=0; i<=pCur->iPage; i++){
    sqlite3PagerUnref(pCur->apPage[i]->pDbPage);
  }
}

/*
** Make sure the BtCursor* given in the argument has a valid
** BtCursor.info structure.  If it is not already valid, call
** sqlite3BtreeParseCell() to fill it in.

** (when less compiler optimizations like -Os or -O0 are used and the
** compiler is not doing agressive inlining.)  So we use a real function
** for MSVC and a macro for everything else.  Ticket #2457.
*/
#ifndef NDEBUG
  static void assertCellInfo(BtCursor *pCur){
    CellInfo info;
    int iPage = pCur->iPage;
    memset(&info, 0, sizeof(info));
    sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &info);
    sqlite3BtreeParseCell(pCur->apPage[iPage], pCur->aiIdx[iPage], &info);
    assert( memcmp(&info, &pCur->info, sizeof(info))==0 );
  }
#else
  #define assertCellInfo(x)
#endif
#ifdef _MSC_VER
  /* Use a real function in MSVC to work around bugs in that compiler. */
  static void getCellInfo(BtCursor *pCur){
    if( pCur->info.nSize==0 ){
      int iPage = pCur->iPage;
      sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info);
      sqlite3BtreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
      pCur->validNKey = 1;
    }else{
      assertCellInfo(pCur);
    }
  }
#else /* if not _MSC_VER */
  /* Use a macro in all other compilers so that the function is inlined */
#define getCellInfo(pCur)                                               \
  if( pCur->info.nSize==0 ){                                            \
    sqlite3BtreeParseCell(pCur->pPage, pCur->idx, &pCur->info);         \
    pCur->validNKey = 1;                                                \
  }else{                                                                \
    assertCellInfo(pCur);                                               \
#define getCellInfo(pCur)                                                      \
  if( pCur->info.nSize==0 ){                                                   \
    int iPage = pCur->iPage;                                                   \
    sqlite3BtreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info); \
    pCur->validNKey = 1;                                                       \
  }else{                                                                       \
    assertCellInfo(pCur);                                                      \
  }
#endif /* _MSC_VER */

/*
** Set *pSize to the size of the buffer needed to hold the value of
** the key for the current entry.  If the cursor is not pointing
** to a valid entry, *pSize is set to 0. 

  int skipKey,         /* offset begins at data if this is true */
  int eOp              /* zero to read. non-zero to write. */
){
  unsigned char *aPayload;
  int rc = SQLITE_OK;
  u32 nKey;
  int iIdx = 0;
  MemPage *pPage = pCur->pPage;     /* Btree page of current cursor entry */
  BtShared *pBt;                   /* Btree this cursor belongs to */
  MemPage *pPage = pCur->apPage[pCur->iPage]; /* Btree page of current entry */
  BtShared *pBt;                              /* Btree this cursor belongs to */

  assert( pPage );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
  assert( offset>=0 );
  assert( cursorHoldsMutex(pCur) );

  getCellInfo(pCur);
  aPayload = pCur->info.pCell + pCur->info.nHeader;
  nKey = (pPage->intKey ? 0 : pCur->info.nKey);

SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
  int rc;

  assert( cursorHoldsMutex(pCur) );
  rc = restoreCursorPosition(pCur);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_VALID );
    assert( pCur->pPage!=0 );
    if( pCur->pPage->intKey ){
    assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
    if( pCur->apPage[0]->intKey ){
      return SQLITE_CORRUPT_BKPT;
    }
    assert( pCur->pPage->intKey==0 );
    assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
    assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
    rc = accessPayload(pCur, offset, amt, (unsigned char*)pBuf, 0, 0);
  }
  return rc;
}

/*
** Read part of the data associated with cursor pCur.  Exactly

  }
#endif

  assert( cursorHoldsMutex(pCur) );
  rc = restoreCursorPosition(pCur);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_VALID );
    assert( pCur->pPage!=0 );
    assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
    assert( pCur->iPage>=0 && pCur->apPage[pCur->iPage] );
    assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
    rc = accessPayload(pCur, offset, amt, pBuf, 1, 0);
  }
  return rc;
}

/*
** Return a pointer to payload information from the entry that the 

  int skipKey          /* read beginning at data if this is true */
){
  unsigned char *aPayload;
  MemPage *pPage;
  u32 nKey;
  int nLocal;

  assert( pCur!=0 && pCur->pPage!=0 );
  assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
  assert( pCur->eState==CURSOR_VALID );
  assert( cursorHoldsMutex(pCur) );
  pPage = pCur->pPage;
  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
  pPage = pCur->apPage[pCur->iPage];
  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
  getCellInfo(pCur);
  aPayload = pCur->info.pCell;
  aPayload += pCur->info.nHeader;
  if( pPage->intKey ){
    nKey = 0;
  }else{
    nKey = pCur->info.nKey;

/*
** Move the cursor down to a new child page.  The newPgno argument is the
** page number of the child page to move to.
*/
static int moveToChild(BtCursor *pCur, u32 newPgno){
  int rc;
  int i = pCur->iPage;
  MemPage *pNewPage;
  MemPage *pOldPage;
  BtShared *pBt = pCur->pBt;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
  if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
    return SQLITE_CORRUPT_BKPT;
  }
  rc = getAndInitPage(pBt, newPgno, &pNewPage, pCur->pPage);
  rc = getAndInitPage(pBt, newPgno, &pNewPage);
  if( rc ) return rc;
  pNewPage->idxParent = pCur->idx;
  pOldPage = pCur->pPage;
  pCur->apPage[i+1] = pNewPage;
  pCur->aiIdx[i+1] = 0;
  pOldPage->idxShift = 0;
  releasePage(pOldPage);
  pCur->pPage = pNewPage;
  pCur->idx = 0;
  pCur->iPage++;

  pCur->info.nSize = 0;
  pCur->validNKey = 0;
  if( pNewPage->nCell<1 ){
    return SQLITE_CORRUPT_BKPT;
  }
  return SQLITE_OK;
}

#ifndef NDEBUG
/*
** Return true if the page is the virtual root of its table.
**
** The virtual root page is the root page for most tables.  But
** for the table rooted on page 1, sometime the real root page
** is empty except for the right-pointer.  In such cases the
** virtual root page is the page that the right-pointer of page
** Page pParent is an internal (non-leaf) tree page. This function 
** asserts that page number iChild is the left-child if the iIdx'th
** cell in page pParent. Or, if iIdx is equal to the total number of
** cells in pParent, that page number iChild is the right-child of
** the page.
** 1 is pointing to.
*/
SQLITE_PRIVATE int sqlite3BtreeIsRootPage(MemPage *pPage){
  MemPage *pParent;

static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){
  assert( iIdx<=pParent->nCell );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pParent = pPage->pParent;
  if( pParent==0 ) return 1;
  if( pParent->pgno>1 ) return 0;
  if( get2byte(&pParent->aData[pParent->hdrOffset+3])==0 ) return 1;
  return 0;
}
  if( iIdx==pParent->nCell ){
    assert( get4byte(&pParent->aData[pParent->hdrOffset+8])==iChild );
  }else{
    assert( get4byte(findCell(pParent, iIdx))==iChild );
  }
}
#else
#  define assertParentIndex(x,y,z) 
#endif

/*
** Move the cursor up to the parent page.
**
** pCur->idx is set to the cell index that contains the pointer
** to the page we are coming from.  If we are coming from the
** right-most child page then pCur->idx is set to one more than
** the largest cell index.
*/
SQLITE_PRIVATE void sqlite3BtreeMoveToParent(BtCursor *pCur){
  MemPage *pParent;
  MemPage *pPage;
  int idxParent;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  pPage = pCur->pPage;
  assert( pPage!=0 );
  assert( pCur->iPage>0 );
  assert( pCur->apPage[pCur->iPage] );
  assert( !sqlite3BtreeIsRootPage(pPage) );
  pParent = pPage->pParent;
  assert( pParent!=0 );
  assert( pPage->pDbPage->nRef>0 );
  idxParent = pPage->idxParent;
  sqlite3PagerRef(pParent->pDbPage);
  releasePage(pPage);
  pCur->pPage = pParent;
  assertParentIndex(
    pCur->apPage[pCur->iPage-1], 
    pCur->aiIdx[pCur->iPage-1], 
    pCur->apPage[pCur->iPage]->pgno
  );
  releasePage(pCur->apPage[pCur->iPage]);
  pCur->iPage--;
  pCur->info.nSize = 0;
  pCur->validNKey = 0;
  assert( pParent->idxShift==0 );
  pCur->idx = idxParent;
}

/*
** Move the cursor to the root page
*/
static int moveToRoot(BtCursor *pCur){
  MemPage *pRoot;
  int rc = SQLITE_OK;
  Btree *p = pCur->pBtree;
  BtShared *pBt = p->pBt;

  assert( cursorHoldsMutex(pCur) );
  assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
  assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );
  assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );
  if( pCur->eState>=CURSOR_REQUIRESEEK ){
    if( pCur->eState==CURSOR_FAULT ){
      return pCur->skip;
    }
    clearCursorPosition(pCur);
    sqlite3BtreeClearCursor(pCur);
  }
  pRoot = pCur->pPage;
  if( pRoot && pRoot->isInit ){
    /* If the page the cursor is currently pointing to is fully initialized,
    ** then the root page can be found by following the MemPage.pParent
    ** pointers. This is faster than requesting a reference to the root
    ** page from the pager layer.
    */
    while( pRoot->pParent ){
      assert( pRoot->isInit==PAGE_ISINIT_FULL );
      pRoot = pRoot->pParent;
    }

    assert( pRoot->isInit==PAGE_ISINIT_FULL );
    if( pRoot!=pCur->pPage ){
      sqlite3PagerRef(pRoot->pDbPage);
      releasePage(pCur->pPage);
  if( pCur->iPage>=0 ){
    int i;
    for(i=1; i<=pCur->iPage; i++){
      releasePage(pCur->apPage[i]);
      pCur->pPage = pRoot;
    }
  }else{
    if( 
      SQLITE_OK!=(rc = getAndInitPage(pBt, pCur->pgnoRoot, &pRoot, 0))
      SQLITE_OK!=(rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]))
    ){
      pCur->eState = CURSOR_INVALID;
      return rc;
    }
    releasePage(pCur->pPage);
    pCur->pPage = pRoot;
  }

  pRoot = pCur->apPage[0];
  assert( pCur->pPage->pgno==pCur->pgnoRoot );
  pCur->idx = 0;
  assert( pRoot->pgno==pCur->pgnoRoot );
  pCur->iPage = 0;
  pCur->aiIdx[0] = 0;
  pCur->info.nSize = 0;
  pCur->atLast = 0;
  pCur->validNKey = 0;

  if( pRoot->nCell==0 && !pRoot->leaf ){
    Pgno subpage;
    assert( pRoot->pgno==1 );
    subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
    assert( subpage>0 );
    pCur->eState = CURSOR_VALID;
    rc = moveToChild(pCur, subpage);
  }else{
    pCur->eState = ((pRoot->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
  }
  pCur->eState = ((pCur->pPage->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
  return rc;
}

/*
** Move the cursor down to the left-most leaf entry beneath the
** entry to which it is currently pointing.
**
** The left-most leaf is the one with the smallest key - the first
** in ascending order.
*/
static int moveToLeftmost(BtCursor *pCur){
  Pgno pgno;
  int rc = SQLITE_OK;
  MemPage *pPage;

  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  while( rc==SQLITE_OK && !(pPage = pCur->pPage)->leaf ){
    assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
    pgno = get4byte(findCell(pPage, pCur->idx));
  while( rc==SQLITE_OK && !(pPage = pCur->apPage[pCur->iPage])->leaf ){
    assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
    pgno = get4byte(findCell(pPage, pCur->aiIdx[pCur->iPage]));
    rc = moveToChild(pCur, pgno);
  }
  return rc;
}

/*
** Move the cursor down to the right-most leaf entry beneath the