components/drive/local_file_reader.cc

   1 // Copyright 2013 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 #include "components/drive/local_file_reader.h"
   6
   7 #include "base/bind.h"
   8 #include "base/files/file_path.h"
   9 #include "base/sequenced_task_runner.h"
  10 #include "net/base/completion_callback.h"
  11 #include "net/base/io_buffer.h"
  12 #include "net/base/net_errors.h"
  13
  14 namespace drive {
  15 namespace util {
  16
  17 LocalFileReader::LocalFileReader(
  18     base::SequencedTaskRunner* sequenced_task_runner)
  19     : file_stream_(sequenced_task_runner),
  20       weak_ptr_factory_(this) {
  21 }
  22
  23 LocalFileReader::~LocalFileReader() {
  24 }
  25
  26 void LocalFileReader::Open(const base::FilePath& file_path,
  27                            int64 offset,
  28                            const net::CompletionCallback& callback) {
  29   DCHECK(!callback.is_null());
  30   int flags = base::File::FLAG_OPEN | base::File::FLAG_READ |
  31               base::File::FLAG_ASYNC;
  32
  33   int rv = file_stream_.Open(file_path, flags,
  34                              Bind(&LocalFileReader::DidOpen,
  35                                   weak_ptr_factory_.GetWeakPtr(),
  36                                   callback, offset));
  37   DCHECK_EQ(rv, net::ERR_IO_PENDING);
  38 }
  39
  40 void LocalFileReader::Read(net::IOBuffer* in_buffer,
  41                            int buffer_length,
  42                            const net::CompletionCallback& callback) {
  43   DCHECK(!callback.is_null());
  44   DCHECK(file_stream_.IsOpen());
  45   int rv = file_stream_.Read(in_buffer, buffer_length, callback);
  46   DCHECK_EQ(rv, net::ERR_IO_PENDING);
  47 }
  48
  49 void LocalFileReader::DidOpen(const net::CompletionCallback& callback,
  50                               int64 offset,
  51                               int error) {
  52   if (error != net::OK)
  53     return callback.Run(error);
  54
  55   int rv = file_stream_.Seek(
  56       offset, Bind(&LocalFileReader::DidSeek, weak_ptr_factory_.GetWeakPtr(),
  57                    callback, offset));
  58   DCHECK_EQ(rv, net::ERR_IO_PENDING);
  59 }
  60
  61 void LocalFileReader::DidSeek(const net::CompletionCallback& callback,
  62                               int64 offset,
  63                               int64 error) {
  64   callback.Run(error == offset ? net::OK : net::ERR_FAILED);
  65 }
  66
  67 }  // namespace util
  68 }  // namespace drive