SQLite

/*
** Allowed values for winFile.ctrlFlags
*/
#define WINFILE_RDONLY          0x02   /* Connection is read only */
#define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
#define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
#define WINFILE_NOLOCK          0x20   /* Never do any real locking */

/*
 * The size of the buffer used by sqlite3_win32_write_debug().
 */
#ifndef SQLITE_WIN32_DBG_BUF_SIZE
#  define SQLITE_WIN32_DBG_BUF_SIZE   ((int)(4096-sizeof(DWORD)))
#endif

  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
  winFile *pFile = (winFile*)id;
  DWORD lastErrno = NO_ERROR;

  assert( id!=0 );
  OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
  if( pFile->ctrlFlags & WINFILE_NOLOCK ){
    return SQLITE_OK;
  }

  /* If there is already a lock of this type or more restrictive on the
  ** OsFile, do nothing. Don't use the end_lock: exit path, as
  ** sqlite3OsEnterMutex() hasn't been called yet.
  */
  if( pFile->locktype>=locktype ){
    OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));

  int rc;
  winFile *pFile = (winFile*)id;

  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
  OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));

  assert( id!=0 );
  if( pFile->ctrlFlags & WINFILE_NOLOCK ){
    rc = 0;
  }else if( pFile->locktype>=RESERVED_LOCK ){
    rc = 1;
    OSTRACE(("TEST-WR-LOCK file=%p, rc=%d (local)\n", pFile->h, rc));
  }else{
    rc = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE, 0, 1, 0);
    if( rc ){
      winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
    }

  int type;
  winFile *pFile = (winFile*)id;
  int rc = SQLITE_OK;
  assert( pFile!=0 );
  assert( locktype<=SHARED_LOCK );
  OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
  if( pFile->ctrlFlags & WINFILE_NOLOCK ){
    return SQLITE_OK;
  }
  type = pFile->locktype;
  if( type>=EXCLUSIVE_LOCK ){
    winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
    if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
      /* This should never happen.  We should always be able to
      ** reacquire the read lock */
      rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),

  pFile->h = h;
  if( isReadonly ){
    pFile->ctrlFlags |= WINFILE_RDONLY;
  }
  if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
    pFile->ctrlFlags |= WINFILE_PSOW;
  }
  if( strcmp(pVfs->zName,"win32-none")==0 ){
    pFile->ctrlFlags |= WINFILE_NOLOCK;
  }
  pFile->lastErrno = NO_ERROR;
  pFile->zPath = zName;
#if SQLITE_MAX_MMAP_SIZE>0
  pFile->hMap = NULL;
  pFile->pMapRegion = 0;
  pFile->mmapSize = 0;
  pFile->mmapSizeActual = 0;

    winGetLastError,     /* xGetLastError */
    winCurrentTimeInt64, /* xCurrentTimeInt64 */
    winSetSystemCall,    /* xSetSystemCall */
    winGetSystemCall,    /* xGetSystemCall */
    winNextSystemCall,   /* xNextSystemCall */
  };
#endif
  static sqlite3_vfs winNoneVfs = {
    3,                   /* iVersion */
    sizeof(winFile),     /* szOsFile */
    SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
    0,                   /* pNext */
    "win32-none",        /* zName */
    0,                   /* pAppData */
    winOpen,             /* xOpen */
    winDelete,           /* xDelete */
    winAccess,           /* xAccess */
    winFullPathname,     /* xFullPathname */
    winDlOpen,           /* xDlOpen */
    winDlError,          /* xDlError */
    winDlSym,            /* xDlSym */
    winDlClose,          /* xDlClose */
    winRandomness,       /* xRandomness */
    winSleep,            /* xSleep */
    winCurrentTime,      /* xCurrentTime */
    winGetLastError,     /* xGetLastError */
    winCurrentTimeInt64, /* xCurrentTimeInt64 */
    winSetSystemCall,    /* xSetSystemCall */
    winGetSystemCall,    /* xGetSystemCall */
    winNextSystemCall,   /* xNextSystemCall */
  };

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==76 );

  /* get memory map allocation granularity */
  memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
#if SQLITE_OS_WINRT
  osGetNativeSystemInfo(&winSysInfo);
#else
  osGetSystemInfo(&winSysInfo);
#endif
  assert( winSysInfo.dwAllocationGranularity>0 );
  assert( winSysInfo.dwPageSize>0 );

  sqlite3_vfs_register(&winVfs, 1);
  sqlite3_vfs_register(&winNoneVfs, 0);

#if defined(SQLITE_WIN32_HAS_WIDE)
  sqlite3_vfs_register(&winLongPathVfs, 0);
#endif

  return SQLITE_OK; 
}