chrome/browser/media_galleries/fileapi/native_media_file_util.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_NATIVE_MEDIA_FILE_UTIL_H_
#define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_NATIVE_MEDIA_FILE_UTIL_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>

#include "base/task/sequenced_task_runner.h"
#include "storage/browser/file_system/async_file_util.h"

namespace net {
class IOBuffer;
}

// Implements the AsyncFileUtil interface to perform native file system
// operations, restricted to operating only on media files.
// Instances must be used, and torn-down, only on the browser IO-thread.
class NativeMediaFileUtil : public storage::AsyncFileUtil {
 public:
  // |media_task_runner| specifies the TaskRunner on which to perform all
  // native file system operations, and media file filtering. This must
  // be the same TaskRunner passed in each FileSystemOperationContext.
  explicit NativeMediaFileUtil(
      scoped_refptr<base::SequencedTaskRunner> media_task_runner);

  NativeMediaFileUtil(const NativeMediaFileUtil&) = delete;
  NativeMediaFileUtil& operator=(const NativeMediaFileUtil&) = delete;

  ~NativeMediaFileUtil() override;

  // Uses the MIME sniffer code, which actually looks into the file,
  // to determine if it is really a media file (to avoid exposing
  // non-media files with a media file extension.)
  static base::File::Error IsMediaFile(const base::FilePath& path);
  static base::File::Error BufferIsMediaHeader(net::IOBuffer* buf,
                                                     size_t length);

  // Methods to support CreateOrOpen. Public so they can be shared with
  // DeviceMediaAsyncFileUtil.
  static void CreatedSnapshotFileForCreateOrOpen(
      base::SequencedTaskRunner* media_task_runner,
      uint32_t file_flags,
      storage::AsyncFileUtil::CreateOrOpenCallback callback,
      base::File::Error result,
      const base::File::Info& file_info,
      const base::FilePath& platform_path,
      scoped_refptr<storage::ShareableFileReference> file_ref);

  // AsyncFileUtil overrides.
  void CreateOrOpen(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      uint32_t file_flags,
      CreateOrOpenCallback callback) override;
  void EnsureFileExists(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      EnsureFileExistsCallback callback) override;
  void CreateDirectory(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      bool exclusive,
      bool recursive,
      StatusCallback callback) override;
  void GetFileInfo(std::unique_ptr<storage::FileSystemOperationContext> context,
                   const storage::FileSystemURL& url,
                   GetMetadataFieldSet fields,
                   GetFileInfoCallback callback) override;
  void ReadDirectory(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      ReadDirectoryCallback callback) override;
  void Touch(std::unique_ptr<storage::FileSystemOperationContext> context,
             const storage::FileSystemURL& url,
             const base::Time& last_access_time,
             const base::Time& last_modified_time,
             StatusCallback callback) override;
  void Truncate(std::unique_ptr<storage::FileSystemOperationContext> context,
                const storage::FileSystemURL& url,
                int64_t length,
                StatusCallback callback) override;
  void CopyFileLocal(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& src_url,
      const storage::FileSystemURL& dest_url,
      CopyOrMoveOptionSet options,
      CopyFileProgressCallback progress_callback,
      StatusCallback callback) override;
  void MoveFileLocal(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& src_url,
      const storage::FileSystemURL& dest_url,
      CopyOrMoveOptionSet options,
      StatusCallback callback) override;
  void CopyInForeignFile(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const base::FilePath& src_file_path,
      const storage::FileSystemURL& dest_url,
      StatusCallback callback) override;
  void DeleteFile(std::unique_ptr<storage::FileSystemOperationContext> context,
                  const storage::FileSystemURL& url,
                  StatusCallback callback) override;
  void DeleteDirectory(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      StatusCallback callback) override;
  void DeleteRecursively(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      StatusCallback callback) override;
  void CreateSnapshotFile(
      std::unique_ptr<storage::FileSystemOperationContext> context,
      const storage::FileSystemURL& url,
      CreateSnapshotFileCallback callback) override;

 private:
  // |core_| holds state which must be used and torn-down on the
  // |media_task_runner_|, rather than on the IO-thread.
  class Core;

  scoped_refptr<base::SequencedTaskRunner> media_task_runner_;
  std::unique_ptr<Core> core_;
};

#endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_NATIVE_MEDIA_FILE_UTIL_H_