text: // Copyright (c) 2012 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 WEBKIT_CHROMEOS_FILEAPI_FILE_SYSTEM_FILE_UTIL_ASYNC_H_
  #define WEBKIT_CHROMEOS_FILEAPI_FILE_SYSTEM_FILE_UTIL_ASYNC_H_
  
  #include "base/callback.h"
  #include "base/file_util_proxy.h"
  #include "base/platform_file.h"
  #include "webkit/chromeos/fileapi/async_file_stream.h"
  
  namespace fileapi {
  
  using base::PlatformFileError;
  
  // The interface class of asynchronous file utils. All functions are pure
  // virtual.
  class FileUtilAsync {
   public:
    virtual ~FileUtilAsync() {}
  
    typedef base::FileUtilProxy::Entry DirectoryEntry;
  
    // Used for GetFileInfo(). |result| is the return code of the operation,
    // and |file_info| is the obtained file info.
    typedef base::Callback<void(
        PlatformFileError result,
        const base::PlatformFileInfo& file_info)> GetFileInfoCallback;
  
    // Used for Create(), etc. |result| is the return code of the operation.
    typedef base::Callback<void(PlatformFileError)> StatusCallback;
  
    // Used for Open(). |result| is the return code of the operation, and
    // |stream| is the stream of the opened file.
    typedef base::Callback<void(
        PlatformFileError result,
        AsyncFileStream* stream)> OpenCallback;
  
    typedef std::vector<DirectoryEntry> FileList;
  
    // Used for ReadDirectoryCallback(). |result| is the return code of the
    // operation, |file_list| is the list of files read, and |completed| is
    // true if all files are read.
    typedef base::Callback<void(
        PlatformFileError result,
        const FileList& file_list,
        bool completed)> ReadDirectoryCallback;
  
    // Opens a file of the given |file_path| with |flags|. On success,
    // PLATFORM_FILE_OK is passed to |callback| with a pointer to newly
    // created AsyncFileStream object. The caller should delete the
    // stream. On failure, an error code is passed instead.
    virtual void Open(const FilePath& file_path,
                      int file_flags,  // PlatformFileFlags
                      const OpenCallback& callback) = 0;
  
    // Gets file info of the given |file_path|. On success,
    // PLATFORM_FILE_OK is passed to |callback| with the the obtained file
    // info. On failure, an error code is passed instead.
    virtual void GetFileInfo(const FilePath& file_path,
                             const GetFileInfoCallback& callback) = 0;
  
    // Creates a file of the given |file_path|. On success,
    // PLATFORM_FILE_OK is passed to |callback|. On failure, an error code
    // is passed instead.
    virtual void Create(const FilePath& file_path,
                        const StatusCallback& callback) = 0;
  
    // Truncates a file of the given |file_path| to |length|. On success,
    // PLATFORM_FILE_OK is passed to |callback|. On failure, an error code
    // is passed instead.
    virtual void Truncate(const FilePath& file_path,
                          int64 length,
                          const StatusCallback& callback) = 0;
  
    // Modifies the timestamps of a file of the given |file_path|. On
    // success, PLATFORM_FILE_OK is passed to |callback|. On failure, an
    // error code is passed instead.
    virtual void Touch(const FilePath& file_path,
                       const base::Time& last_access_time,
                       const base::Time& last_modified_time,
                       const StatusCallback& callback) = 0;
  
    // Removes a file or directory of the given |file_path|. If |recursive|
    // is true, removes the contents of the given directory recursively. On
    // success, PLATFORM_FILE_OK is passed to |callback|. On failure, an
    // error code is passed instead.
    virtual void Remove(const FilePath& file_path,
                        bool recursive,
                        const StatusCallback& callback) = 0;
  
    // Creates a directory of the given |dir_path|. On success,
    // PLATFORM_FILE_OK is passed to |callback|. On failure, an error code
    // is passed instead.
    virtual void CreateDirectory(const FilePath& dir_path,
                                 const StatusCallback& callback) = 0;
  
    // Reads a directory of the given |dir_path|. On success,
    // PLATFORM_FILE_OK is passed to |callback| with the list of files, and
    // a boolean value indicating if all files are read. On failure, an
    // error code is passed instead.
    //
    // The ReadDirectoryCallback may be called several times, returning the
    // portions of the whole directory listing. The reference to vector with
    // DirectoryEntry objects, passed to callback is guaranteed to contain the
    // results of the operation only while callback is running.
    //
    // The implementations of FileUtilAsync should be careful to populate the
    // vector on the same thread, on which the callback is called. Otherwise,
    // if callback is called through PostTask, the data might get overwritten
    // before callback is actually called.
    //
    // TODO(olege): Maybe make it possible to read only a part of the directory.
    virtual void ReadDirectory(const FilePath& dir_path,
                               const ReadDirectoryCallback& callback) = 0;
  
    // TODO(olege): Add LocalCopy and LocalMove.
  };
  
  }  // namespace fileapi
  
  #endif  // WEBKIT_CHROMEOS_FILEAPI_FILE_SYSTEM_FILE_UTIL_ASYNC_H_
  