root/chrome/browser/media_galleries/fileapi/device_media_async_file_util.h

INCLUDED FROM

// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// 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_DEVICE_MEDIA_ASYNC_FILE_UTIL_H_
#define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_DEVICE_MEDIA_ASYNC_FILE_UTIL_H_

#include "base/files/file.h"
#include "base/files/file_path.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "webkit/browser/fileapi/async_file_util.h"
#include "webkit/common/blob/shareable_file_reference.h"

namespace base {
class SequencedTaskRunner;
class Time;
}

namespace fileapi {
class FileSystemOperationContext;
class FileSystemURL;
}

namespace net {
class IOBuffer;
}

namespace webkit_blob {
class FileStreamReader;
}

class DeviceMediaAsyncFileUtil : public fileapi::AsyncFileUtil {
 public:
  virtual ~DeviceMediaAsyncFileUtil();

  // Returns an instance of DeviceMediaAsyncFileUtil. Returns NULL if
  // asynchronous operation is not supported. Callers own the returned
  // object.
  static DeviceMediaAsyncFileUtil* Create(const base::FilePath& profile_path);

  bool SupportsStreaming(const fileapi::FileSystemURL& url);

  // AsyncFileUtil overrides.
  virtual void CreateOrOpen(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      int file_flags,
      const CreateOrOpenCallback& callback) OVERRIDE;
  virtual void EnsureFileExists(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const EnsureFileExistsCallback& callback) OVERRIDE;
  virtual void CreateDirectory(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      bool exclusive,
      bool recursive,
      const StatusCallback& callback) OVERRIDE;
  virtual void GetFileInfo(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const GetFileInfoCallback& callback) OVERRIDE;
  virtual void ReadDirectory(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const ReadDirectoryCallback& callback) OVERRIDE;
  virtual void Touch(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const base::Time& last_access_time,
      const base::Time& last_modified_time,
      const StatusCallback& callback) OVERRIDE;
  virtual void Truncate(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      int64 length,
      const StatusCallback& callback) OVERRIDE;
  virtual void CopyFileLocal(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& src_url,
      const fileapi::FileSystemURL& dest_url,
      CopyOrMoveOption option,
      const CopyFileProgressCallback& progress_callback,
      const StatusCallback& callback) OVERRIDE;
  virtual void MoveFileLocal(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& src_url,
      const fileapi::FileSystemURL& dest_url,
      CopyOrMoveOption option,
      const StatusCallback& callback) OVERRIDE;
  virtual void CopyInForeignFile(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const base::FilePath& src_file_path,
      const fileapi::FileSystemURL& dest_url,
      const StatusCallback& callback) OVERRIDE;
  virtual void DeleteFile(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const StatusCallback& callback) OVERRIDE;
  virtual void DeleteDirectory(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const StatusCallback& callback) OVERRIDE;
  virtual void DeleteRecursively(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const StatusCallback& callback) OVERRIDE;
  virtual void CreateSnapshotFile(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const fileapi::FileSystemURL& url,
      const CreateSnapshotFileCallback& callback) OVERRIDE;

  // This method is called when existing Blobs are read.
  // |expected_modification_time| indicates the expected snapshot state of the
  // underlying storage. The returned FileStreamReader must return an error
  // when the state of the underlying storage changes. Any errors associated
  // with reading this file are returned by the FileStreamReader itself.
  virtual scoped_ptr<webkit_blob::FileStreamReader> GetFileStreamReader(
      const fileapi::FileSystemURL& url,
      int64 offset,
      const base::Time& expected_modification_time,
      fileapi::FileSystemContext* context);

 private:
  // Use Create() to get an instance of DeviceMediaAsyncFileUtil.
  explicit DeviceMediaAsyncFileUtil(const base::FilePath& profile_path);

  // Called when GetFileInfo method call succeeds. |file_info| contains the
  // file details of the requested url. |callback| is invoked to complete the
  // GetFileInfo request.
  void OnDidGetFileInfo(
      const AsyncFileUtil::GetFileInfoCallback& callback,
      const base::File::Info& file_info);

  // Called when GetFileInfo method call failed to get the details of file
  // specified by the requested url. |callback| is invoked to notify the
  // caller about the platform file |error|.
  void OnGetFileInfoError(
      const AsyncFileUtil::GetFileInfoCallback& callback,
      base::File::Error error);

  // Called when ReadDirectory method call succeeds. |callback| is invoked to
  // complete the ReadDirectory request.
  //
  // If the contents of the given directory are reported in one batch, then
  // |file_list| will have the list of all files/directories in the given
  // directory and |has_more| will be false.
  //
  // If the contents of the given directory are reported in multiple chunks,
  // |file_list| will have only a subset of all contents (the subsets reported
  // in any two calls are disjoint), and |has_more| will be true, except for
  // the last chunk.
  void OnDidReadDirectory(
      const AsyncFileUtil::ReadDirectoryCallback& callback,
      const AsyncFileUtil::EntryList& file_list,
      bool has_more);

  // Called when ReadDirectory method call failed to enumerate the directory
  // objects. |callback| is invoked to notify the caller about the |error|
  // that occured while reading the directory objects.
  void OnReadDirectoryError(
      const AsyncFileUtil::ReadDirectoryCallback& callback,
      base::File::Error error);

  // Called when the snapshot file specified by the |platform_path| is
  // successfully created. |file_info| contains the device media file details
  // for which the snapshot file is created.
  void OnDidCreateSnapshotFile(
      const AsyncFileUtil::CreateSnapshotFileCallback& callback,
      base::SequencedTaskRunner* media_task_runner,
      const base::File::Info& file_info,
      const base::FilePath& platform_path);

  // Called after OnDidCreateSnapshotFile finishes media check.
  // |callback| is invoked to complete the CreateSnapshotFile request.
  void OnDidCheckMedia(
      const AsyncFileUtil::CreateSnapshotFileCallback& callback,
      const base::File::Info& file_info,
      scoped_refptr<webkit_blob::ShareableFileReference> platform_file,
      base::File::Error error);

  // Called when CreateSnapshotFile method call fails. |callback| is invoked to
  // notify the caller about the |error|.
  void OnCreateSnapshotFileError(
      const AsyncFileUtil::CreateSnapshotFileCallback& callback,
      base::File::Error error);

  // Called when the snapshot file specified by the |snapshot_file_path| is
  // created to hold the contents of the url.path(). If the snapshot
  // file is successfully created, |snapshot_file_path| will be an non-empty
  // file path. In case of failure, |snapshot_file_path| will be an empty file
  // path. Forwards the CreateSnapshot request to the delegate to copy the
  // contents of url.path() to |snapshot_file_path|.
  void OnSnapshotFileCreatedRunTask(
      scoped_ptr<fileapi::FileSystemOperationContext> context,
      const AsyncFileUtil::CreateSnapshotFileCallback& callback,
      const fileapi::FileSystemURL& url,
      base::FilePath* snapshot_file_path);

  // Profile path.
  const base::FilePath profile_path_;

  // For callbacks that may run after destruction.
  base::WeakPtrFactory<DeviceMediaAsyncFileUtil> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(DeviceMediaAsyncFileUtil);
};

#endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_DEVICE_MEDIA_ASYNC_FILE_UTIL_H_