engine/sqlite/src/journal.cpp
changeset 97 3903521a36da
parent 96 87e863f6f840
child 98 5f9e7e14eb11
--- a/engine/sqlite/src/journal.cpp	Wed May 26 10:44:32 2010 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,238 +0,0 @@
-/*
-** 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.
-**
-*************************************************************************
-**
-** @(#) $Id: journal.cpp 1282 2008-11-13 09:31:33Z LarsPson $
-*/
-
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
-
-/*
-** 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 xSync() method is called.
-*/
-
-#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);
-      }
-    }
-  }
-  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{
-    assert( iAmt+iOfst<=p->iSize );
-    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;
-  rc = createFile(p);
-  if( rc==SQLITE_OK ){
-    rc = sqlite3OsSync(p->pReal, flags);
-  }
-  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 */
-};
-
-/* 
-** 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;
-    }
-  }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);
-}
-
-/* 
-** 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