media/filters/file_data_source.cc

   1 // Copyright (c) 2012 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 "media/filters/file_data_source.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/logging.h"
  10
  11 namespace media {
  12
  13 FileDataSource::FileDataSource()
  14     : force_read_errors_(false),
  15       force_streaming_(false) {
  16 }
  17
  18 bool FileDataSource::Initialize(const base::FilePath& file_path) {
  19   DCHECK(!file_.IsValid());
  20
  21   if (!file_.Initialize(file_path))
  22     return false;
  23
  24   UpdateHostBytes();
  25   return true;
  26 }
  27
  28 bool FileDataSource::InitializeFromPlatformFile(
  29     const base::PlatformFile& file) {
  30   DCHECK(!file_.IsValid());
  31
  32   if (!file_.Initialize(file))
  33     return false;
  34
  35   UpdateHostBytes();
  36   return true;
  37 }
  38
  39 void FileDataSource::set_host(DataSourceHost* host) {
  40   DataSource::set_host(host);
  41   UpdateHostBytes();
  42 }
  43
  44 void FileDataSource::Stop(const base::Closure& callback) {
  45   callback.Run();
  46 }
  47
  48 void FileDataSource::Read(int64 position, int size, uint8* data,
  49                           const DataSource::ReadCB& read_cb) {
  50   if (force_read_errors_ || !file_.IsValid()) {
  51     read_cb.Run(kReadError);
  52     return;
  53   }
  54
  55   int64 file_size = file_.length();
  56
  57   CHECK_GE(file_size, 0);
  58   CHECK_GE(position, 0);
  59   CHECK_GE(size, 0);
  60
  61   // Cap position and size within bounds.
  62   position = std::min(position, file_size);
  63   int64 clamped_size = std::min(static_cast<int64>(size), file_size - position);
  64
  65   memcpy(data, file_.data() + position, clamped_size);
  66   read_cb.Run(clamped_size);
  67 }
  68
  69 bool FileDataSource::GetSize(int64* size_out) {
  70   *size_out = file_.length();
  71   return true;
  72 }
  73
  74 bool FileDataSource::IsStreaming() {
  75   return force_streaming_;
  76 }
  77
  78 void FileDataSource::SetBitrate(int bitrate) {}
  79
  80 FileDataSource::~FileDataSource() {}
  81
  82 void FileDataSource::UpdateHostBytes() {
  83   if (host() && file_.IsValid()) {
  84     host()->SetTotalBytes(file_.length());
  85     host()->AddBufferedByteRange(0, file_.length());
  86   }
  87 }
  88
  89 }  // namespace media