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_READER_H_
6#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_
7
8#include "base/basictypes.h"
9#include "base/files/file_path.h"
10#include "base/memory/weak_ptr.h"
11#include "webkit/browser/blob/file_stream_reader.h"
12#include "webkit/browser/fileapi/file_system_url.h"
13
14namespace fileapi {
15class AsyncFileUtil;
16}  // namespace fileapi
17
18namespace chromeos {
19namespace file_system_provider {
20
21class ProvidedFileSystemInterface;
22
23// Implements a streamed file reader. It is lazily initialized by the first call
24// to Read().
25class FileStreamReader : public webkit_blob::FileStreamReader {
26 public:
27  typedef base::Callback<
28      void(base::WeakPtr<ProvidedFileSystemInterface> file_system,
29           const base::FilePath& file_path,
30           int file_handle,
31           base::File::Error result)> InitializeCompletedCallback;
32
33  FileStreamReader(fileapi::FileSystemContext* context,
34                   const fileapi::FileSystemURL& url,
35                   int64 initial_offset,
36                   const base::Time& expected_modification_time);
37
38  virtual ~FileStreamReader();
39
40  // webkit_blob::FileStreamReader overrides.
41  virtual int Read(net::IOBuffer* buf,
42                   int buf_len,
43                   const net::CompletionCallback& callback) OVERRIDE;
44  virtual int64 GetLength(
45      const net::Int64CompletionCallback& callback) OVERRIDE;
46
47 private:
48  // Initializes the reader by opening the file. When completed with success,
49  // runs the |pending_closure|. Otherwise, calls the |error_callback|.
50  void Initialize(const base::Closure& pending_closure,
51                  const net::Int64CompletionCallback& error_callback);
52
53  // Called when initializing is completed with either a success or an error.
54  void OnInitializeCompleted(
55      const base::Closure& pending_closure,
56      const net::Int64CompletionCallback& error_callback,
57      base::WeakPtr<ProvidedFileSystemInterface> file_system,
58      const base::FilePath& file_path,
59      int file_handle,
60      base::File::Error result);
61
62  // Called when a file system provider returns chunk of read data. Note, that
63  // this may be called multiple times per single Read() call, as long as
64  // |has_more| is set to true. |result| is set to success only if reading is
65  // successful, and the file has not changed while reading.
66  void OnReadChunkReceived(const net::CompletionCallback& callback,
67                           int chunk_length,
68                           bool has_more,
69                           base::File::Error result);
70
71  // Called when fetching length of the file is completed with either a success
72  // or an error.
73  void OnGetMetadataForGetLengthReceived(
74      const net::Int64CompletionCallback& callback,
75      base::File::Error result,
76      const base::File::Info& file_info);
77
78  // Same as Read(), but called after initializing is completed.
79  void ReadAfterInitialized(scoped_refptr<net::IOBuffer> buffer,
80                            int buffer_length,
81                            const net::CompletionCallback& callback);
82
83  // Same as GetLength(), but called after initializing is completed.
84  void GetLengthAfterInitialized(const net::Int64CompletionCallback& callback);
85
86  fileapi::FileSystemURL url_;
87  int64 current_offset_;
88  int64 current_length_;
89  base::Time expected_modification_time_;
90
91  // Set during initialization (in case of a success).
92  base::WeakPtr<ProvidedFileSystemInterface> file_system_;
93  base::FilePath file_path_;
94  int file_handle_;
95
96  base::WeakPtrFactory<FileStreamReader> weak_ptr_factory_;
97  DISALLOW_COPY_AND_ASSIGN(FileStreamReader);
98};
99
100}  // namespace file_system_provider
101}  // namespace chromeos
102
103#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_
104