third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteFileSystemPosix.cpp

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

// Expose chromium_sqlite3_* functions from Chromium's patched SQLite.
#define CHROMIUM_SQLITE_INTERNALS

#include "modules/webdatabase/sqlite/SQLiteFileSystem.h"

#include "public/platform/Platform.h"
#include "third_party/sqlite/sqlite3.h"

#include <fcntl.h>
#include <string.h>
#include <unistd.h>

namespace blink {

// Chromium's Posix implementation of SQLite VFS
namespace {

struct chromiumVfsFile {
  sqlite3_io_methods* pMethods;
  sqlite3_file* wrappedFile;
  char* wrappedFileName;
};

int chromiumClose(sqlite3_file* sqliteFile) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  int r =
      chromiumFile->wrappedFile->pMethods->xClose(chromiumFile->wrappedFile);
  sqlite3_free(chromiumFile->wrappedFileName);
  sqlite3_free(chromiumFile->wrappedFile);
  memset(chromiumFile, 0, sizeof(*chromiumFile));
  return r;
}

int chromiumRead(sqlite3_file* sqliteFile,
                 void* pBuf,
                 int iAmt,
                 sqlite3_int64 iOfst) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xRead(chromiumFile->wrappedFile,
                                                    pBuf, iAmt, iOfst);
}

int chromiumWrite(sqlite3_file* sqliteFile,
                  const void* pBuf,
                  int iAmt,
                  sqlite3_int64 iOfst) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xWrite(chromiumFile->wrappedFile,
                                                     pBuf, iAmt, iOfst);
}

int chromiumTruncate(sqlite3_file* sqliteFile, sqlite3_int64 size) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);

  // The OSX and Linux sandboxes block ftruncate(), proxy to the browser
  // process.
  if (Platform::current()->databaseSetFileSize(
          String(chromiumFile->wrappedFileName), size))
    return SQLITE_OK;
  return SQLITE_IOERR_TRUNCATE;
}

int chromiumSync(sqlite3_file* sqliteFile, int flags) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xSync(chromiumFile->wrappedFile,
                                                    flags);
}

int chromiumFileSize(sqlite3_file* sqliteFile, sqlite3_int64* pSize) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xFileSize(
      chromiumFile->wrappedFile, pSize);
}

int chromiumLock(sqlite3_file* sqliteFile, int eFileLock) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xLock(chromiumFile->wrappedFile,
                                                    eFileLock);
}

int chromiumUnlock(sqlite3_file* sqliteFile, int eFileLock) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xUnlock(chromiumFile->wrappedFile,
                                                      eFileLock);
}

int chromiumCheckReservedLock(sqlite3_file* sqliteFile, int* pResOut) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xCheckReservedLock(
      chromiumFile->wrappedFile, pResOut);
}

int chromiumFileControl(sqlite3_file* sqliteFile, int op, void* pArg) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xFileControl(
      chromiumFile->wrappedFile, op, pArg);
}

int chromiumSectorSize(sqlite3_file* sqliteFile) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xSectorSize(
      chromiumFile->wrappedFile);
}

int chromiumDeviceCharacteristics(sqlite3_file* sqliteFile) {
  chromiumVfsFile* chromiumFile =
      reinterpret_cast<chromiumVfsFile*>(sqliteFile);
  return chromiumFile->wrappedFile->pMethods->xDeviceCharacteristics(
      chromiumFile->wrappedFile);
}

// Opens a file.
//
// vfs - pointer to the sqlite3_vfs object.
// fileName - the name of the file.
// id - the structure that will manipulate the newly opened file.
// desiredFlags - the desired open mode flags.
// usedFlags - the actual open mode flags that were used.
int chromiumOpenInternal(sqlite3_vfs* vfs,
                         const char* fileName,
                         sqlite3_file* id,
                         int desiredFlags,
                         int* usedFlags) {
  int fd =
      Platform::current()->databaseOpenFile(String(fileName), desiredFlags);
  if ((fd < 0) && (desiredFlags & SQLITE_OPEN_READWRITE)) {
    desiredFlags =
        (desiredFlags & ~(SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE)) |
        SQLITE_OPEN_READONLY;
    fd = Platform::current()->databaseOpenFile(String(fileName), desiredFlags);
  }
  if (fd < 0)
    return SQLITE_CANTOPEN;

  if (usedFlags)
    *usedFlags = desiredFlags;

  fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);

  // The mask 0x00007F00 gives us the 7 bits that determine the type of the file
  // SQLite is trying to open.
  int fileType = desiredFlags & 0x00007F00;
  int noLock = (fileType != SQLITE_OPEN_MAIN_DB);
  sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
  return chromium_sqlite3_fill_in_unix_sqlite3_file(
      wrappedVfs, fd, id, fileName, noLock, desiredFlags);
}

int chromiumOpen(sqlite3_vfs* vfs,
                 const char* fileName,
                 sqlite3_file* id,
                 int desiredFlags,
                 int* usedFlags) {
  sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
  sqlite3_file* wrappedFile =
      static_cast<sqlite3_file*>(sqlite3_malloc(wrappedVfs->szOsFile));
  if (!wrappedFile)
    return SQLITE_NOMEM;

  // Make a local copy of the file name.  SQLite's os_unix.c appears to be
  // written to allow caching the pointer passed in to this function, but that
  // seems brittle.
  char* wrappedFileName = sqlite3_mprintf("%s", fileName);
  if (!wrappedFileName) {
    sqlite3_free(wrappedFile);
    return SQLITE_NOMEM;
  }

  // SQLite's unixOpen() makes assumptions about the structure of |fileName|.
  // Our local copy may not answer those assumptions correctly.
  int rc =
      chromiumOpenInternal(vfs, fileName, wrappedFile, desiredFlags, usedFlags);
  if (rc != SQLITE_OK) {
    sqlite3_free(wrappedFileName);
    sqlite3_free(wrappedFile);
    return rc;
  }

  static sqlite3_io_methods chromiumIoMethods = {
      1,
      chromiumClose,
      chromiumRead,
      chromiumWrite,
      chromiumTruncate,
      chromiumSync,
      chromiumFileSize,
      chromiumLock,
      chromiumUnlock,
      chromiumCheckReservedLock,
      chromiumFileControl,
      chromiumSectorSize,
      chromiumDeviceCharacteristics,
      // Methods above are valid for version 1.
  };
  chromiumVfsFile* chromiumFile = reinterpret_cast<chromiumVfsFile*>(id);
  chromiumFile->pMethods = &chromiumIoMethods;
  chromiumFile->wrappedFile = wrappedFile;
  chromiumFile->wrappedFileName = wrappedFileName;
  return SQLITE_OK;
}

// Deletes the given file.
//
// vfs - pointer to the sqlite3_vfs object.
// fileName - the name of the file.
// syncDir - determines if the directory to which this file belongs
//           should be synched after the file is deleted.
int chromiumDelete(sqlite3_vfs*, const char* fileName, int syncDir) {
  return Platform::current()->databaseDeleteFile(String(fileName), syncDir);
}

// Check the existance and status of the given file.
//
// vfs - pointer to the sqlite3_vfs object.
// fileName - the name of the file.
// flag - the type of test to make on this file.
// res - the result.
int chromiumAccess(sqlite3_vfs*, const char* fileName, int flag, int* res) {
  int attr = static_cast<int>(
      Platform::current()->databaseGetFileAttributes(String(fileName)));
  if (attr < 0) {
    *res = 0;
    return SQLITE_OK;
  }

  switch (flag) {
    case SQLITE_ACCESS_EXISTS:
      *res = 1;  // if the file doesn't exist, attr < 0
      break;
    case SQLITE_ACCESS_READWRITE:
      *res = (attr & W_OK) && (attr & R_OK);
      break;
    case SQLITE_ACCESS_READ:
      *res = (attr & R_OK);
      break;
    default:
      return SQLITE_ERROR;
  }

  return SQLITE_OK;
}

// Turns a relative pathname into a full pathname.
//
// vfs - pointer to the sqlite3_vfs object.
// relativePath - the relative path.
// bufSize - the size of the output buffer in bytes.
// absolutePath - the output buffer where the absolute path will be stored.
int chromiumFullPathname(sqlite3_vfs* vfs,
                         const char* relativePath,
                         int bufSize,
                         char* absolutePath) {
  // The renderer process doesn't need to know the absolute path of the file
  sqlite3_snprintf(bufSize, absolutePath, "%s", relativePath);
  return SQLITE_OK;
}

// Do not allow loading libraries in the renderer.
void* chromiumDlOpen(sqlite3_vfs*, const char*) {
  return 0;
}

void chromiumDlError(sqlite3_vfs*, int bufSize, char* errorBuffer) {
  sqlite3_snprintf(bufSize, errorBuffer, "Dynamic loading not supported");
}

void (*chromiumDlSym(sqlite3_vfs*, void*, const char*))(void) {
  return 0;
}

void chromiumDlClose(sqlite3_vfs*, void*) {}

int chromiumRandomness(sqlite3_vfs* vfs, int bufSize, char* buffer) {
  sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
  return wrappedVfs->xRandomness(wrappedVfs, bufSize, buffer);
}

int chromiumSleep(sqlite3_vfs* vfs, int microseconds) {
  sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
  return wrappedVfs->xSleep(wrappedVfs, microseconds);
}

int chromiumCurrentTime(sqlite3_vfs* vfs, double* prNow) {
  sqlite3_vfs* wrappedVfs = static_cast<sqlite3_vfs*>(vfs->pAppData);
  return wrappedVfs->xCurrentTime(wrappedVfs, prNow);
}

int chromiumGetLastError(sqlite3_vfs* vfs, int e, char* s) {
  // xGetLastError() has never been used by SQLite.  The implementation in
  // os_win.c indicates this is a reasonable implementation.
  *s = '\0';
  return 0;
}

}  // namespace

void SQLiteFileSystem::registerSQLiteVFS() {
  sqlite3_vfs* wrappedVfs = sqlite3_vfs_find("unix");

  // These are implemented by delegating to |wrappedVfs|.
  // TODO(shess): Implement local versions.
  ASSERT(wrappedVfs->xRandomness);
  ASSERT(wrappedVfs->xSleep);
  ASSERT(wrappedVfs->xCurrentTime);

  static sqlite3_vfs chromium_vfs = {1,
                                     sizeof(chromiumVfsFile),
                                     wrappedVfs->mxPathname,
                                     0,
                                     "chromium_vfs",
                                     wrappedVfs,
                                     chromiumOpen,
                                     chromiumDelete,
                                     chromiumAccess,
                                     chromiumFullPathname,
                                     chromiumDlOpen,
                                     chromiumDlError,
                                     chromiumDlSym,
                                     chromiumDlClose,
                                     chromiumRandomness,
                                     chromiumSleep,
                                     chromiumCurrentTime,
                                     chromiumGetLastError};
  sqlite3_vfs_register(&chromium_vfs, 0);
}

}  // namespace blink