webkit_file_stream_reader_impl.h revision 5d1f7b1de12d16ceb2c938c56701a3e8bfa558f7 
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_DRIVE_FILEAPI_WEBKIT_FILE_STREAM_READER_IMPL_H_
6#define CHROME_BROWSER_CHROMEOS_DRIVE_FILEAPI_WEBKIT_FILE_STREAM_READER_IMPL_H_
7
8#include "base/basictypes.h"
9#include "base/files/file_path.h"
10#include "base/memory/ref_counted.h"
11#include "base/memory/scoped_ptr.h"
12#include "base/memory/weak_ptr.h"
13#include "base/time/time.h"
14#include "chrome/browser/chromeos/drive/drive_file_stream_reader.h"
15#include "net/base/completion_callback.h"
16#include "webkit/browser/blob/file_stream_reader.h"
17
18namespace base {
19class SequencedTaskRunner;
20}  // namespace base
21
22namespace drive {
23
24class ResourceEntry;
25
26namespace internal {
27
28// The implementation of webkit_blob::FileStreamReader for drive file system.
29// webkit_blob::FileStreamReader does not provide a way for explicit
30// initialization, hence the initialization of this class will be done lazily.
31// Note that when crbug.com/225339 is resolved, this class will be also
32// initialized explicitly.
33class WebkitFileStreamReaderImpl : public webkit_blob::FileStreamReader {
34 public:
35  WebkitFileStreamReaderImpl(
36      const DriveFileStreamReader::FileSystemGetter& file_system_getter,
37      base::SequencedTaskRunner* file_task_runner,
38      const base::FilePath& drive_file_path,
39      int64 offset,
40      const base::Time& expected_modification_time);
41  virtual ~WebkitFileStreamReaderImpl();
42
43  // webkit_blob::FileStreamReader override.
44  virtual int Read(net::IOBuffer* buffer,
45                   int buffer_length,
46                   const net::CompletionCallback& callback) OVERRIDE;
47  virtual int64 GetLength(const net::Int64CompletionCallback& callback)
48      OVERRIDE;
49
50 private:
51  // Called upon the initialization completion of |stream_reader_|.
52  // Processes the result of the initialization with checking last
53  // modified time, and calls |callback| with net::Error code as its result.
54  void OnStreamReaderInitialized(
55      const net::CompletionCallback& callback,
56      int error,
57      scoped_ptr<ResourceEntry> entry);
58
59  // Part of Read(). Called after all the initialization process is completed.
60  void ReadAfterStreamReaderInitialized(
61      scoped_refptr<net::IOBuffer> buffer,
62      int buffer_length,
63      const net::CompletionCallback& callback,
64      int initialization_result);
65
66  // Part of GetLength(). Called after all the initialization process is
67  // completed.
68  void GetLengthAfterStreamReaderInitialized(
69      const net::Int64CompletionCallback& callback,
70      int initialization_result);
71
72  scoped_ptr<DriveFileStreamReader> stream_reader_;
73  const base::FilePath drive_file_path_;
74  const int64 offset_;
75  const base::Time expected_modification_time_;
76
77  // This is available only after initialize is done.
78  int64 file_size_;
79
80  // This should remain the last member so it'll be destroyed first and
81  // invalidate its weak pointers before other members are destroyed.
82  base::WeakPtrFactory<WebkitFileStreamReaderImpl> weak_ptr_factory_;
83  DISALLOW_COPY_AND_ASSIGN(WebkitFileStreamReaderImpl);
84};
85
86}  // namespace internal
87}  // namespace drive
88
89#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILEAPI_WEBKIT_FILE_STREAM_READER_IMPL_H_
90