expr.lo fault.lo fkey.lo \
         fts3.lo fts3_aux.lo fts3_expr.lo fts3_hash.lo fts3_icu.lo \
         fts3_porter.lo fts3_snippet.lo fts3_tokenizer.lo fts3_tokenizer1.lo \
         fts3_tokenize_vtab.lo \
         fts3_unicode.lo fts3_unicode2.lo fts3_write.lo \
	 fts5.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo journal.lo json1.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memjournal.lo \
         mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         pager.lo parse.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo select.lo sqlite3rbu.lo status.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
................................................................................
  $(TOP)/src/fkey.c \
  $(TOP)/src/func.c \
  $(TOP)/src/global.c \
  $(TOP)/src/hash.c \
  $(TOP)/src/hash.h \
  $(TOP)/src/hwtime.h \
  $(TOP)/src/insert.c \
  $(TOP)/src/journal.c \
  $(TOP)/src/legacy.c \
  $(TOP)/src/loadext.c \
  $(TOP)/src/main.c \
  $(TOP)/src/malloc.c \
  $(TOP)/src/mem0.c \
  $(TOP)/src/mem1.c \
  $(TOP)/src/mem2.c \
................................................................................

hash.lo:	$(TOP)/src/hash.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/hash.c

insert.lo:	$(TOP)/src/insert.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/insert.c

journal.lo:	$(TOP)/src/journal.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/journal.c

legacy.lo:	$(TOP)/src/legacy.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/legacy.c

loadext.lo:	$(TOP)/src/loadext.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/loadext.c

main.lo:	$(TOP)/src/main.c $(HDR)

         expr.lo fault.lo fkey.lo \
         fts3.lo fts3_aux.lo fts3_expr.lo fts3_hash.lo fts3_icu.lo \
         fts3_porter.lo fts3_snippet.lo fts3_tokenizer.lo fts3_tokenizer1.lo \
         fts3_tokenize_vtab.lo \
         fts3_unicode.lo fts3_unicode2.lo fts3_write.lo \
	 fts5.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo json1.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memjournal.lo \
         mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         pager.lo parse.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo select.lo sqlite3rbu.lo status.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
................................................................................
  $(TOP)/src/fkey.c \
  $(TOP)/src/func.c \
  $(TOP)/src/global.c \
  $(TOP)/src/hash.c \
  $(TOP)/src/hash.h \
  $(TOP)/src/hwtime.h \
  $(TOP)/src/insert.c \

  $(TOP)/src/legacy.c \
  $(TOP)/src/loadext.c \
  $(TOP)/src/main.c \
  $(TOP)/src/malloc.c \
  $(TOP)/src/mem0.c \
  $(TOP)/src/mem1.c \
  $(TOP)/src/mem2.c \
................................................................................

hash.lo:	$(TOP)/src/hash.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/hash.c

insert.lo:	$(TOP)/src/insert.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/insert.c




legacy.lo:	$(TOP)/src/legacy.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/legacy.c

loadext.lo:	$(TOP)/src/loadext.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/loadext.c

main.lo:	$(TOP)/src/main.c $(HDR)

         callback.lo complete.lo ctime.lo date.lo dbstat.lo delete.lo \
         expr.lo fault.lo fkey.lo \
         fts3.lo fts3_aux.lo fts3_expr.lo fts3_hash.lo fts3_icu.lo \
         fts3_porter.lo fts3_snippet.lo fts3_tokenizer.lo fts3_tokenizer1.lo \
         fts3_tokenize_vtab.lo fts3_unicode.lo fts3_unicode2.lo fts3_write.lo \
         fts5.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo journal.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memjournal.lo \
         mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         pager.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo select.lo sqlite3rbu.lo status.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
................................................................................
  $(TOP)\src\expr.c \
  $(TOP)\src\fault.c \
  $(TOP)\src\fkey.c \
  $(TOP)\src\func.c \
  $(TOP)\src\global.c \
  $(TOP)\src\hash.c \
  $(TOP)\src\insert.c \
  $(TOP)\src\journal.c \
  $(TOP)\src\legacy.c \
  $(TOP)\src\loadext.c \
  $(TOP)\src\main.c \
  $(TOP)\src\malloc.c \
  $(TOP)\src\mem0.c \
  $(TOP)\src\mem1.c \
  $(TOP)\src\mem2.c \
................................................................................

hash.lo:	$(TOP)\src\hash.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\hash.c

insert.lo:	$(TOP)\src\insert.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\insert.c

journal.lo:	$(TOP)\src\journal.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\journal.c

legacy.lo:	$(TOP)\src\legacy.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\legacy.c

loadext.lo:	$(TOP)\src\loadext.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\loadext.c

main.lo:	$(TOP)\src\main.c $(HDR)

         callback.lo complete.lo ctime.lo date.lo dbstat.lo delete.lo \
         expr.lo fault.lo fkey.lo \
         fts3.lo fts3_aux.lo fts3_expr.lo fts3_hash.lo fts3_icu.lo \
         fts3_porter.lo fts3_snippet.lo fts3_tokenizer.lo fts3_tokenizer1.lo \
         fts3_tokenize_vtab.lo fts3_unicode.lo fts3_unicode2.lo fts3_write.lo \
         fts5.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memjournal.lo \
         mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         pager.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo select.lo sqlite3rbu.lo status.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
................................................................................
  $(TOP)\src\expr.c \
  $(TOP)\src\fault.c \
  $(TOP)\src\fkey.c \
  $(TOP)\src\func.c \
  $(TOP)\src\global.c \
  $(TOP)\src\hash.c \
  $(TOP)\src\insert.c \

  $(TOP)\src\legacy.c \
  $(TOP)\src\loadext.c \
  $(TOP)\src\main.c \
  $(TOP)\src\malloc.c \
  $(TOP)\src\mem0.c \
  $(TOP)\src\mem1.c \
  $(TOP)\src\mem2.c \
................................................................................

hash.lo:	$(TOP)\src\hash.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\hash.c

insert.lo:	$(TOP)\src\insert.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\insert.c




legacy.lo:	$(TOP)\src\legacy.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\legacy.c

loadext.lo:	$(TOP)\src\loadext.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\loadext.c

main.lo:	$(TOP)\src\main.c $(HDR)

         callback.o complete.o ctime.o date.o dbstat.o delete.o expr.o \
	 fault.o fkey.o \
         fts3.o fts3_aux.o fts3_expr.o fts3_hash.o fts3_icu.o fts3_porter.o \
         fts3_snippet.o fts3_tokenizer.o fts3_tokenizer1.o \
         fts3_tokenize_vtab.o \
	 fts3_unicode.o fts3_unicode2.o \
         fts3_write.o fts5.o func.o global.o hash.o \
         icu.o insert.o journal.o json1.o legacy.o loadext.o \
         main.o malloc.o mem0.o mem1.o mem2.o mem3.o mem5.o \
         memjournal.o \
         mutex.o mutex_noop.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_unix.o os_win.o \
         pager.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o select.o sqlite3rbu.o status.o \
         table.o threads.o tokenize.o treeview.o trigger.o \
................................................................................
  $(TOP)/src/fkey.c \
  $(TOP)/src/func.c \
  $(TOP)/src/global.c \
  $(TOP)/src/hash.c \
  $(TOP)/src/hash.h \
  $(TOP)/src/hwtime.h \
  $(TOP)/src/insert.c \
  $(TOP)/src/journal.c \
  $(TOP)/src/legacy.c \
  $(TOP)/src/loadext.c \
  $(TOP)/src/main.c \
  $(TOP)/src/malloc.c \
  $(TOP)/src/mem0.c \
  $(TOP)/src/mem1.c \
  $(TOP)/src/mem2.c \

         callback.o complete.o ctime.o date.o dbstat.o delete.o expr.o \
	 fault.o fkey.o \
         fts3.o fts3_aux.o fts3_expr.o fts3_hash.o fts3_icu.o fts3_porter.o \
         fts3_snippet.o fts3_tokenizer.o fts3_tokenizer1.o \
         fts3_tokenize_vtab.o \
	 fts3_unicode.o fts3_unicode2.o \
         fts3_write.o fts5.o func.o global.o hash.o \
         icu.o insert.o json1.o legacy.o loadext.o \
         main.o malloc.o mem0.o mem1.o mem2.o mem3.o mem5.o \
         memjournal.o \
         mutex.o mutex_noop.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_unix.o os_win.o \
         pager.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o select.o sqlite3rbu.o status.o \
         table.o threads.o tokenize.o treeview.o trigger.o \
................................................................................
  $(TOP)/src/fkey.c \
  $(TOP)/src/func.c \
  $(TOP)/src/global.c \
  $(TOP)/src/hash.c \
  $(TOP)/src/hash.h \
  $(TOP)/src/hwtime.h \
  $(TOP)/src/insert.c \

  $(TOP)/src/legacy.c \
  $(TOP)/src/loadext.c \
  $(TOP)/src/main.c \
  $(TOP)/src/malloc.c \
  $(TOP)/src/mem0.c \
  $(TOP)/src/mem1.c \
  $(TOP)/src/mem2.c \

/*
** 2007 August 22
**
** 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 implements a special kind of sqlite3_file object used
** by SQLite to create journal files if the atomic-write optimization
** is enabled.
**
** The distinctive characteristic of this sqlite3_file is that the
** actual on disk file is created lazily. When the file is created,
** the caller specifies a buffer size for an in-memory buffer to
** be used to service read() and write() requests. The actual file
** on disk is not created or populated until either:
**
**   1) The in-memory representation grows too large for the allocated 
**      buffer, or
**   2) The sqlite3JournalCreate() function is called.
*/
#if 0 
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
#include "sqliteInt.h"


/*
** A JournalFile object is a subclass of sqlite3_file used by
** as an open file handle for journal files.
*/
struct JournalFile {
  sqlite3_io_methods *pMethod;    /* I/O methods on journal files */
  int nBuf;                       /* Size of zBuf[] in bytes */
  char *zBuf;                     /* Space to buffer journal writes */
  int iSize;                      /* Amount of zBuf[] currently used */
  int flags;                      /* xOpen flags */
  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
  sqlite3_file *pReal;            /* The "real" underlying file descriptor */
  const char *zJournal;           /* Name of the journal file */
};
typedef struct JournalFile JournalFile;

/*
** If it does not already exists, create and populate the on-disk file 
** for JournalFile p.
*/
static int createFile(JournalFile *p){
  int rc = SQLITE_OK;
  if( !p->pReal ){
    sqlite3_file *pReal = (sqlite3_file *)&p[1];
    rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
    if( rc==SQLITE_OK ){
      p->pReal = pReal;
      if( p->iSize>0 ){
        assert(p->iSize<=p->nBuf);
        rc = sqlite3OsWrite(p->pReal, p->zBuf, p->iSize, 0);
      }
      if( rc!=SQLITE_OK ){
        /* If an error occurred while writing to the file, close it before
        ** returning. This way, SQLite uses the in-memory journal data to 
        ** roll back changes made to the internal page-cache before this
        ** function was called.  */
        sqlite3OsClose(pReal);
        p->pReal = 0;
      }
    }
  }
  return rc;
}

/*
** Close the file.
*/
static int jrnlClose(sqlite3_file *pJfd){
  JournalFile *p = (JournalFile *)pJfd;
  if( p->pReal ){
    sqlite3OsClose(p->pReal);
  }
  sqlite3_free(p->zBuf);
  return SQLITE_OK;
}

/*
** Read data from the file.
*/
static int jrnlRead(
  sqlite3_file *pJfd,    /* The journal file from which to read */
  void *zBuf,            /* Put the results here */
  int iAmt,              /* Number of bytes to read */
  sqlite_int64 iOfst     /* Begin reading at this offset */
){
  int rc = SQLITE_OK;
  JournalFile *p = (JournalFile *)pJfd;
  if( p->pReal ){
    rc = sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
  }else if( (iAmt+iOfst)>p->iSize ){
    rc = SQLITE_IOERR_SHORT_READ;
  }else{
    memcpy(zBuf, &p->zBuf[iOfst], iAmt);
  }
  return rc;
}

/*
** Write data to the file.
*/
static int jrnlWrite(
  sqlite3_file *pJfd,    /* The journal file into which to write */
  const void *zBuf,      /* Take data to be written from here */
  int iAmt,              /* Number of bytes to write */
  sqlite_int64 iOfst     /* Begin writing at this offset into the file */
){
  int rc = SQLITE_OK;
  JournalFile *p = (JournalFile *)pJfd;
  if( !p->pReal && (iOfst+iAmt)>p->nBuf ){
    rc = createFile(p);
  }
  if( rc==SQLITE_OK ){
    if( p->pReal ){
      rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
    }else{
      memcpy(&p->zBuf[iOfst], zBuf, iAmt);
      if( p->iSize<(iOfst+iAmt) ){
        p->iSize = (iOfst+iAmt);
      }
    }
  }
  return rc;
}

/*
** Truncate the file.
*/
static int jrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
  int rc = SQLITE_OK;
  JournalFile *p = (JournalFile *)pJfd;
  if( p->pReal ){
    rc = sqlite3OsTruncate(p->pReal, size);
  }else if( size<p->iSize ){
    p->iSize = size;
  }
  return rc;
}

/*
** Sync the file.
*/
static int jrnlSync(sqlite3_file *pJfd, int flags){
  int rc;
  JournalFile *p = (JournalFile *)pJfd;
  if( p->pReal ){
    rc = sqlite3OsSync(p->pReal, flags);
  }else{
    rc = SQLITE_OK;
  }
  return rc;
}

/*
** Query the size of the file in bytes.
*/
static int jrnlFileSize(sqlite3_file *pJfd, sqlite_int64 *pSize){
  int rc = SQLITE_OK;
  JournalFile *p = (JournalFile *)pJfd;
  if( p->pReal ){
    rc = sqlite3OsFileSize(p->pReal, pSize);
  }else{
    *pSize = (sqlite_int64) p->iSize;
  }
  return rc;
}

/*
** Table of methods for JournalFile sqlite3_file object.
*/
static struct sqlite3_io_methods JournalFileMethods = {
  1,             /* iVersion */
  jrnlClose,     /* xClose */
  jrnlRead,      /* xRead */
  jrnlWrite,     /* xWrite */
  jrnlTruncate,  /* xTruncate */
  jrnlSync,      /* xSync */
  jrnlFileSize,  /* xFileSize */
  0,             /* xLock */
  0,             /* xUnlock */
  0,             /* xCheckReservedLock */
  0,             /* xFileControl */
  0,             /* xSectorSize */
  0,             /* xDeviceCharacteristics */
  0,             /* xShmMap */
  0,             /* xShmLock */
  0,             /* xShmBarrier */
  0              /* xShmUnmap */
};

/* 
** Open a journal file.
*/
int sqlite3JournalOpen(
  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
  const char *zName,         /* Name of the journal file */
  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
  int flags,                 /* Opening flags */
  int nBuf                   /* Bytes buffered before opening the file */
){
  JournalFile *p = (JournalFile *)pJfd;
  memset(p, 0, sqlite3JournalSize(pVfs));
  if( nBuf>0 ){
    p->zBuf = sqlite3MallocZero(nBuf);
    if( !p->zBuf ){
      return SQLITE_NOMEM_BKPT;
    }
  }else{
    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
  }
  p->pMethod = &JournalFileMethods;
  p->nBuf = nBuf;
  p->flags = flags;
  p->zJournal = zName;
  p->pVfs = pVfs;
  return SQLITE_OK;
}

/*
** If the argument p points to a JournalFile structure, and the underlying
** file has not yet been created, create it now.
*/
int sqlite3JournalCreate(sqlite3_file *p){
  if( p->pMethods!=&JournalFileMethods ){
    return SQLITE_OK;
  }
  return createFile((JournalFile *)p);
}

/*
** The file-handle passed as the only argument is guaranteed to be an open
** file. It may or may not be of class JournalFile. If the file is a
** JournalFile, and the underlying file on disk has not yet been opened,
** return 0. Otherwise, return 1.
*/
int sqlite3JournalExists(sqlite3_file *p){
  return (p->pMethods!=&JournalFileMethods || ((JournalFile *)p)->pReal!=0);
}

/* 
** Return the number of bytes required to store a JournalFile that uses vfs
** pVfs to create the underlying on-disk files.
*/
int sqlite3JournalSize(sqlite3_vfs *pVfs){
  return (pVfs->szOsFile+sizeof(JournalFile));
}
#endif
#endif

** This structure is a subclass of sqlite3_file. Each open memory-journal
** is an instance of this class.
*/
struct MemJournal {
  const sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */
  int nChunkSize;                 /* In-memory chunk-size */

  int nBuf;                       /* Bytes of data before flushing */
  int nSize;                      /* Bytes of data currently in memory */
  FileChunk *pFirst;              /* Head of in-memory chunk-list */
  FilePoint endpoint;             /* Pointer to the end of the file */
  FilePoint readpoint;            /* Pointer to the end of the last xRead() */

  int flags;                      /* xOpen flags */
  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
................................................................................
  } 
  p->pFirst = 0;
}

/*
** Flush the contents of memory to a real file on disk.
*/
static int createFile(MemJournal *p){
  int rc = SQLITE_OK;
  if( !p->pReal ){
    sqlite3_file *pReal = (sqlite3_file *)&p[1];
    rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
    if( rc==SQLITE_OK ){
      int nChunk = p->nChunkSize;
      i64 iOff = 0;
................................................................................

  /* If the file has already been created on disk. */
  if( p->pReal ){
    return sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
  }

  /* If the file should be created now. */
  else if( p->nBuf>0 && (iAmt+iOfst)>p->nBuf ){
    int rc = createFile(p);
    if( rc==SQLITE_OK ){
      rc = memjrnlWrite(pJfd, zBuf, iAmt, iOfst);
    }
    return rc;
  }

  /* If the contents of this write should be stored in memory */
................................................................................
  0                 /* xUnfetch */
};

/* 
** Open a journal file. 
**
** The behaviour of the journal file depends on the value of parameter 
** nBuf. If nBuf is 0, then the journal file is always create and 
** accessed using the underlying VFS. If nBuf is less than zero, then
** all content is always stored in main-memory. Finally, if nBuf is a
** positive value, then the journal file is initially created in-memory
** but may be flushed to disk later on. In this case the journal file is
** flushed to disk either when it grows larger than nBuf bytes in size,
** or when sqlite3JournalCreate() is called.
*/
int sqlite3JournalOpen(
  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
  const char *zName,         /* Name of the journal file */
  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
  int flags,                 /* Opening flags */
  int nBuf                   /* Bytes buffered before opening the file */
){
  MemJournal *p = (MemJournal*)pJfd;

  /* Zero the file-handle object. If nBuf was passed zero, initialize
  ** it using the sqlite3OsOpen() function of the underlying VFS. In this
  ** case none of the code in this module is executed as a result of calls
  ** made on the journal file-handle.  */
  memset(p, 0, sizeof(MemJournal) + (pVfs ? pVfs->szOsFile : 0));
  if( nBuf==0 ){
    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
  }

  if( nBuf>0 ){
    p->nChunkSize = nBuf;
  }else{
    p->nChunkSize = 8 + MEMJOURNAL_DFLT_FILECHUNKSIZE - sizeof(FileChunk);
    assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) );
  }

  p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods;
  p->nBuf = nBuf;
  p->flags = flags;
  p->zJournal = zName;
  p->pVfs = pVfs;
  return SQLITE_OK;
}

/*
................................................................................
  sqlite3JournalOpen(0, 0, pJfd, 0, -1);
}

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
/*
** If the argument p points to a MemJournal structure that is not an 
** in-memory-only journal file (i.e. is one that was opened with a +ve
** nBuf parameter), and the underlying file has not yet been created, 
** create it now.
*/
int sqlite3JournalCreate(sqlite3_file *p){
  int rc = SQLITE_OK;
  if( p->pMethods==&MemJournalMethods && ((MemJournal*)p)->nBuf>0 ){
    rc = createFile((MemJournal*)p);
  }
  return rc;
}
#endif

/*
** The file-handle passed as the only argument is open on a journal file.

** This structure is a subclass of sqlite3_file. Each open memory-journal
** is an instance of this class.
*/
struct MemJournal {
  const sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */
  int nChunkSize;                 /* In-memory chunk-size */

  int nSpill;                     /* Bytes of data before flushing */
  int nSize;                      /* Bytes of data currently in memory */
  FileChunk *pFirst;              /* Head of in-memory chunk-list */
  FilePoint endpoint;             /* Pointer to the end of the file */
  FilePoint readpoint;            /* Pointer to the end of the last xRead() */

  int flags;                      /* xOpen flags */
  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
................................................................................
  } 
  p->pFirst = 0;
}

/*
** Flush the contents of memory to a real file on disk.
*/
static int memjrnlCreateFile(MemJournal *p){
  int rc = SQLITE_OK;
  if( !p->pReal ){
    sqlite3_file *pReal = (sqlite3_file *)&p[1];
    rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
    if( rc==SQLITE_OK ){
      int nChunk = p->nChunkSize;
      i64 iOff = 0;
................................................................................

  /* If the file has already been created on disk. */
  if( p->pReal ){
    return sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
  }

  /* If the file should be created now. */
  else if( p->nSpill>0 && (iAmt+iOfst)>p->nSpill ){
    int rc = memjrnlCreateFile(p);
    if( rc==SQLITE_OK ){
      rc = memjrnlWrite(pJfd, zBuf, iAmt, iOfst);
    }
    return rc;
  }

  /* If the contents of this write should be stored in memory */
................................................................................
  0                 /* xUnfetch */
};

/* 
** Open a journal file. 
**
** The behaviour of the journal file depends on the value of parameter 
** nSpill. If nSpill is 0, then the journal file is always create and 
** accessed using the underlying VFS. If nSpill is less than zero, then
** all content is always stored in main-memory. Finally, if nSpill is a
** positive value, then the journal file is initially created in-memory
** but may be flushed to disk later on. In this case the journal file is
** flushed to disk either when it grows larger than nSpill bytes in size,
** or when sqlite3JournalCreate() is called.
*/
int sqlite3JournalOpen(
  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
  const char *zName,         /* Name of the journal file */
  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
  int flags,                 /* Opening flags */
  int nSpill                 /* Bytes buffered before opening the file */
){
  MemJournal *p = (MemJournal*)pJfd;

  /* Zero the file-handle object. If nSpill was passed zero, initialize
  ** it using the sqlite3OsOpen() function of the underlying VFS. In this
  ** case none of the code in this module is executed as a result of calls
  ** made on the journal file-handle.  */
  memset(p, 0, sizeof(MemJournal) + (pVfs ? pVfs->szOsFile : 0));
  if( nSpill==0 ){
    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
  }

  if( nSpill>0 ){
    p->nChunkSize = nSpill;
  }else{
    p->nChunkSize = 8 + MEMJOURNAL_DFLT_FILECHUNKSIZE - sizeof(FileChunk);
    assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) );
  }

  p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods;
  p->nSpill = nSpill;
  p->flags = flags;
  p->zJournal = zName;
  p->pVfs = pVfs;
  return SQLITE_OK;
}

/*
................................................................................
  sqlite3JournalOpen(0, 0, pJfd, 0, -1);
}

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
/*
** If the argument p points to a MemJournal structure that is not an 
** in-memory-only journal file (i.e. is one that was opened with a +ve
** nSpill parameter), and the underlying file has not yet been created, 
** create it now.
*/
int sqlite3JournalCreate(sqlite3_file *p){
  int rc = SQLITE_OK;
  if( p->pMethods==&MemJournalMethods && ((MemJournal*)p)->nSpill>0 ){
    rc = memjrnlCreateFile((MemJournal*)p);
  }
  return rc;
}
#endif

/*
** The file-handle passed as the only argument is open on a journal file.

   vdbemem.c
   vdbeaux.c
   vdbeapi.c
   vdbetrace.c
   vdbe.c
   vdbeblob.c
   vdbesort.c
   journal.c
   memjournal.c

   walker.c
   resolve.c
   expr.c
   alter.c
   analyze.c

   vdbemem.c
   vdbeaux.c
   vdbeapi.c
   vdbetrace.c
   vdbe.c
   vdbeblob.c
   vdbesort.c

   memjournal.c

   walker.c
   resolve.c
   expr.c
   alter.c
   analyze.c