file_stream_writer.h revision 1320f92c476a1ad9d19dba2a48c72b75566198e9 
1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_WRITER_H_
6#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_WRITER_H_
7
8#include "base/basictypes.h"
9#include "base/files/file.h"
10#include "base/files/file_path.h"
11#include "base/memory/ref_counted.h"
12#include "base/memory/weak_ptr.h"
13#include "storage/browser/fileapi/file_stream_writer.h"
14#include "storage/browser/fileapi/file_system_url.h"
15
16namespace chromeos {
17namespace file_system_provider {
18
19class ProvidedFileSystemInterface;
20
21// Implements a streamed file writer. It is lazily initialized by the first call
22// to Write().
23class FileStreamWriter : public storage::FileStreamWriter {
24 public:
25  FileStreamWriter(const storage::FileSystemURL& url, int64 initial_offset);
26
27  virtual ~FileStreamWriter();
28
29  // storage::FileStreamWriter overrides.
30  virtual int Write(net::IOBuffer* buf,
31                    int buf_len,
32                    const net::CompletionCallback& callback) OVERRIDE;
33  virtual int Cancel(const net::CompletionCallback& callback) OVERRIDE;
34  virtual int Flush(const net::CompletionCallback& callback) OVERRIDE;
35
36 private:
37  // Helper class for executing operations on the provided file system. All
38  // of its methods must be called on UI thread. Callbacks are called on IO
39  // thread.
40  class OperationRunner;
41
42  // State of the file stream writer.
43  enum State { NOT_INITIALIZED, INITIALIZING, INITIALIZED, FAILED };
44
45  // Called when OperationRunner::WriteOnUIThread is completed.
46  void OnWriteFileCompleted(int buffer_length,
47                            const net::CompletionCallback& callback,
48                            base::File::Error result);
49
50  // Called when Write() operation is completed with either a success or an
51  // error.
52  void OnWriteCompleted(net::CompletionCallback callback, int result);
53
54  // Called when Abort() operation is completed with either a success or an
55  // error.
56  void OnAbortCompleted(const net::CompletionCallback& callback,
57                        base::File::Error result);
58
59  // Initializes the writer by opening the file. When completed with success,
60  // runs the |pending_closure|. Otherwise, calls the |error_callback|.
61  void Initialize(const base::Closure& pending_closure,
62                  const net::CompletionCallback& error_callback);
63
64  // Called when opening a file is completed with either a success or an error.
65  void OnOpenFileCompleted(
66      const base::Closure& pending_closure,
67      const net::CompletionCallback& error_callback,
68      base::File::Error result);
69
70  // Same as Write(), but called after initializing is completed.
71  void WriteAfterInitialized(scoped_refptr<net::IOBuffer> buffer,
72                             int buffer_length,
73                             const net::CompletionCallback& callback);
74
75  storage::FileSystemURL url_;
76  int64 current_offset_;
77  scoped_refptr<OperationRunner> runner_;
78  State state_;
79
80  base::WeakPtrFactory<FileStreamWriter> weak_ptr_factory_;
81  DISALLOW_COPY_AND_ASSIGN(FileStreamWriter);
82};
83
84}  // namespace file_system_provider
85}  // namespace chromeos
86
87#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_WRITER_H_
88