test_onefile.c

最新的sqlite3.6.2源代码

    int iBuf = 0;
    int ii = iOfst;
    while( iRem>0 && rc==SQLITE_OK ){
      int iRealOff = pReal->nBlob - BLOCKSIZE*((ii/BLOCKSIZE)+1) + ii%BLOCKSIZE;
      int iRealAmt = MIN(iRem, BLOCKSIZE - (iRealOff%BLOCKSIZE));

      rc = pF->pMethods->xRead(pF, &((char *)zBuf)[iBuf], iRealAmt, iRealOff);
      ii += iRealAmt;
      iBuf += iRealAmt;
      iRem -= iRealAmt;
    }
  }

  return rc;
}

/*
** Write data to an fs-file.
*/
static int fsWrite(
  sqlite3_file *pFile, 
  const void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  int rc = SQLITE_OK;
  fs_file *p = (fs_file *)pFile;
  fs_real_file *pReal = p->pReal;
  sqlite3_file *pF = pReal->pFile;

  if( p->eType==DATABASE_FILE ){
    if( (iAmt+iOfst+BLOCKSIZE)>(pReal->nBlob-pReal->nJournal) ){
      rc = SQLITE_FULL;
    }else{
      rc = pF->pMethods->xWrite(pF, zBuf, iAmt, iOfst+BLOCKSIZE);
      if( rc==SQLITE_OK ){
        pReal->nDatabase = MAX(pReal->nDatabase, iAmt+iOfst);
      }
    }
  }else{
    /* Journal file. */
    int iRem = iAmt;
    int iBuf = 0;
    int ii = iOfst;
    while( iRem>0 && rc==SQLITE_OK ){
      int iRealOff = pReal->nBlob - BLOCKSIZE*((ii/BLOCKSIZE)+1) + ii%BLOCKSIZE;
      int iRealAmt = MIN(iRem, BLOCKSIZE - (iRealOff%BLOCKSIZE));

      if( iRealOff<(pReal->nDatabase+BLOCKSIZE) ){
        rc = SQLITE_FULL;
      }else{
        rc = pF->pMethods->xWrite(pF, &((char *)zBuf)[iBuf], iRealAmt,iRealOff);
        ii += iRealAmt;
        iBuf += iRealAmt;
        iRem -= iRealAmt;
      }
    }
    if( rc==SQLITE_OK ){
      pReal->nJournal = MAX(pReal->nJournal, iAmt+iOfst);
    }
  }

  return rc;
}

/*
** Truncate an fs-file.
*/
static int fsTruncate(sqlite3_file *pFile, sqlite_int64 size){
  fs_file *p = (fs_file *)pFile;
  fs_real_file *pReal = p->pReal;
  if( p->eType==DATABASE_FILE ){
    pReal->nDatabase = MIN(pReal->nDatabase, size);
  }else{
    pReal->nJournal = MIN(pReal->nJournal, size);
  }
  return SQLITE_OK;
}

/*
** Sync an fs-file.
*/
static int fsSync(sqlite3_file *pFile, int flags){
  fs_file *p = (fs_file *)pFile;
  fs_real_file *pReal = p->pReal;
  sqlite3_file *pRealFile = pReal->pFile;
  int rc = SQLITE_OK;

  if( p->eType==DATABASE_FILE ){
    unsigned char zSize[4];
    zSize[0] = (pReal->nDatabase&0xFF000000)>>24;
    zSize[1] = (pReal->nDatabase&0x00FF0000)>>16;
    zSize[2] = (pReal->nDatabase&0x0000FF00)>>8;
    zSize[3] = (pReal->nDatabase&0x000000FF);
    rc = pRealFile->pMethods->xWrite(pRealFile, zSize, 4, 0);
  }
  if( rc==SQLITE_OK ){
    rc = pRealFile->pMethods->xSync(pRealFile, flags&(~SQLITE_SYNC_DATAONLY));
  }

  return rc;
}

/*
** Return the current file-size of an fs-file.
*/
static int fsFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  fs_file *p = (fs_file *)pFile;
  fs_real_file *pReal = p->pReal;
  if( p->eType==DATABASE_FILE ){
    *pSize = pReal->nDatabase;
  }else{
    *pSize = pReal->nJournal;
  }
  return SQLITE_OK;
}

/*
** Lock an fs-file.
*/
static int fsLock(sqlite3_file *pFile, int eLock){
  return SQLITE_OK;
}

/*
** Unlock an fs-file.
*/
static int fsUnlock(sqlite3_file *pFile, int eLock){
  return SQLITE_OK;
}

/*
** Check if another file-handle holds a RESERVED lock on an fs-file.
*/
static int fsCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  *pResOut = 0;
  return SQLITE_OK;
}

/*
** File control method. For custom operations on an fs-file.
*/
static int fsFileControl(sqlite3_file *pFile, int op, void *pArg){
  return SQLITE_OK;
}

/*
** Return the sector-size in bytes for an fs-file.
*/
static int fsSectorSize(sqlite3_file *pFile){
  return BLOCKSIZE;
}

/*
** Return the device characteristic flags supported by an fs-file.
*/
static int fsDeviceCharacteristics(sqlite3_file *pFile){
  return 0;
}

/*
** Open an fs file handle.
*/
static int fsOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs;
  fs_file *p = (fs_file *)pFile;
  fs_real_file *pReal = 0;
  int eType;
  int nName;
  int rc = SQLITE_OK;

  if( 0==(flags&(SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_MAIN_JOURNAL)) ){
    tmp_file *p = (tmp_file *)pFile;
    memset(p, 0, sizeof(*p));
    p->base.pMethods = &tmp_io_methods;
    return SQLITE_OK;
  }

  eType = ((flags&(SQLITE_OPEN_MAIN_DB))?DATABASE_FILE:JOURNAL_FILE);
  p->base.pMethods = &fs_io_methods;
  p->eType = eType;

  assert(strlen("-journal")==8);
  nName = strlen(zName)-((eType==JOURNAL_FILE)?8:0);
  pReal=pFsVfs->pFileList; 
  for(; pReal && strncmp(pReal->zName, zName, nName); pReal=pReal->pNext);

  if( !pReal ){
    sqlite3_int64 size;
    sqlite3_file *pRealFile;
    sqlite3_vfs *pParent = pFsVfs->pParent;
    assert(eType==DATABASE_FILE);

    pReal = (fs_real_file *)sqlite3_malloc(sizeof(*pReal)+pParent->szOsFile);
    if( !pReal ){
      rc = SQLITE_NOMEM;
      goto open_out;
    }
    memset(pReal, 0, sizeof(*pReal)+pParent->szOsFile);
    pReal->zName = zName;
    pReal->pFile = (sqlite3_file *)(&pReal[1]);

    rc = pParent->xOpen(pParent, zName, pReal->pFile, flags, pOutFlags);
    if( rc!=SQLITE_OK ){
      goto open_out;
    }
    pRealFile = pReal->pFile;

    rc = pRealFile->pMethods->xFileSize(pRealFile, &size);
    if( rc!=SQLITE_OK ){
      goto open_out;
    }
    if( size==0 ){
      rc = pRealFile->pMethods->xWrite(pRealFile, "\0", 1, BLOBSIZE-1);
      pReal->nBlob = BLOBSIZE;
    }else{
      unsigned char zS[4];
      pReal->nBlob = size;
      rc = pRealFile->pMethods->xRead(pRealFile, zS, 4, 0);
      pReal->nDatabase = (zS[0]<<24)+(zS[1]<<16)+(zS[2]<<8)+zS[3];
      if( rc==SQLITE_OK ){
        rc = pRealFile->pMethods->xRead(pRealFile, zS, 4, pReal->nBlob-4);
        if( zS[0] || zS[1] || zS[2] || zS[3] ){
          pReal->nJournal = pReal->nBlob;
        }
      }
    }

    if( rc==SQLITE_OK ){
      pReal->pNext = pFsVfs->pFileList;
      if( pReal->pNext ){
        pReal->pNext->ppThis = &pReal->pNext;
      }
      pReal->ppThis = &pFsVfs->pFileList;
      pFsVfs->pFileList = pReal;
    }
  }

open_out:
  if( pReal ){
    if( rc==SQLITE_OK ){
      p->pReal = pReal;
      pReal->nRef++;
    }else{
      if( pReal->pFile->pMethods ){
        pReal->pFile->pMethods->xClose(pReal->pFile);
      }
      sqlite3_free(pReal);
    }
  }
  return rc;
}

/*
** Delete the file located at zPath. If the dirSync argument is true,
** ensure the file-system modifications are synced to disk before
** returning.
*/
static int fsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  int rc = SQLITE_OK;
  fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs;
  fs_real_file *pReal;
  sqlite3_file *pF;
  int nName = strlen(zPath) - 8;

  assert(strlen("-journal")==8);
  assert(strcmp("-journal", &zPath[nName])==0);

  pReal = pFsVfs->pFileList; 
  for(; pReal && strncmp(pReal->zName, zPath, nName); pReal=pReal->pNext);
  if( pReal ){
    pF = pReal->pFile;
    rc = pF->pMethods->xWrite(pF, "\0\0\0\0", 4, pReal->nBlob-BLOCKSIZE);
    if( rc==SQLITE_OK ){
      pReal->nJournal = 0;
    }
  }
  return rc;
}

/*
** Test for access permissions. Return true if the requested permission
** is available, or false otherwise.
*/
static int fsAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  fs_vfs_t *pFsVfs = (fs_vfs_t *)pVfs;
  fs_real_file *pReal;
  int isJournal = 0;
  int nName = strlen(zPath);

  if( flags!=SQLITE_ACCESS_EXISTS ){
    sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
    return pParent->xAccess(pParent, zPath, flags, pResOut);
  }

  assert(strlen("-journal")==8);
  if( nName>8 && strcmp("-journal", &zPath[nName-8])==0 ){
    nName -= 8;
    isJournal = 1;
  }

  pReal = pFsVfs->pFileList; 
  for(; pReal && strncmp(pReal->zName, zPath, nName); pReal=pReal->pNext);

  *pResOut = (pReal && (!isJournal || pReal->nJournal>0));
  return SQLITE_OK;
}

/*
** Populate buffer zOut with the full canonical pathname corresponding
** to the pathname in zPath. zOut is guaranteed to point to a buffer
** of at least (FS_MAX_PATHNAME+1) bytes.
*/
static int fsFullPathname(
  sqlite3_vfs *pVfs,            /* Pointer to vfs object */
  const char *zPath,            /* Possibly relative input path */
  int nOut,                     /* Size of output buffer in bytes */
  char *zOut                    /* Output buffer */
){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  return pParent->xFullPathname(pParent, zPath, nOut, zOut);
}

/*
** Open the dynamic library located at zPath and return a handle.
*/
static void *fsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  return pParent->xDlOpen(pParent, zPath);
}

/*
** Populate the buffer zErrMsg (size nByte bytes) with a human readable
** utf-8 string describing the most recent error encountered associated 
** with dynamic libraries.
*/
static void fsDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  pParent->xDlError(pParent, nByte, zErrMsg);
}

/*
** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
*/
static void *fsDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  return pParent->xDlSym(pParent, pHandle, zSymbol);
}

/*
** Close the dynamic library handle pHandle.
*/
static void fsDlClose(sqlite3_vfs *pVfs, void *pHandle){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  pParent->xDlClose(pParent, pHandle);
}

/*
** Populate the buffer pointed to by zBufOut with nByte bytes of 
** random data.
*/
static int fsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  return pParent->xRandomness(pParent, nByte, zBufOut);
}

/*
** Sleep for nMicro microseconds. Return the number of microseconds 
** actually slept.
*/
static int fsSleep(sqlite3_vfs *pVfs, int nMicro){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  return pParent->xSleep(pParent, nMicro);
}

/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int fsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  sqlite3_vfs *pParent = ((fs_vfs_t *)pVfs)->pParent;
  return pParent->xCurrentTime(pParent, pTimeOut);
}

/*
** This procedure registers the fs vfs with SQLite. If the argument is
** true, the fs vfs becomes the new default vfs. It is the only publicly
** available function in this file.
*/
int fs_register(){
  if( fs_vfs.pParent ) return SQLITE_OK;
  fs_vfs.pParent = sqlite3_vfs_find(0);
  fs_vfs.base.mxPathname = fs_vfs.pParent->mxPathname;
  fs_vfs.base.szOsFile = MAX(sizeof(tmp_file), sizeof(fs_file));
  return sqlite3_vfs_register(&fs_vfs.base, 0);
}

#ifdef SQLITE_TEST
  int SqlitetestOnefile_Init() {return fs_register();}
#endif