chrome/utility/media_galleries/ipc_data_source.cc

   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 #include "chrome/utility/media_galleries/ipc_data_source.h"
   6
   7 #include "base/message_loop/message_loop_proxy.h"
   8 #include "chrome/common/chrome_utility_messages.h"
   9 #include "content/public/utility/utility_thread.h"
  10
  11 namespace metadata {
  12
  13 IPCDataSource::IPCDataSource(int64 total_size)
  14     : total_size_(total_size),
  15       utility_task_runner_(base::MessageLoopProxy::current()),
  16       next_request_id_(0) {
  17   data_source_thread_checker_.DetachFromThread();
  18 }
  19
  20 IPCDataSource::~IPCDataSource() {
  21   DCHECK(utility_thread_checker_.CalledOnValidThread());
  22 }
  23
  24 void IPCDataSource::set_host(media::DataSourceHost* host) {
  25   DCHECK(data_source_thread_checker_.CalledOnValidThread());
  26   DataSource::set_host(host);
  27   if (media::DataSource::host()) {
  28     media::DataSource::host()->SetTotalBytes(total_size_);
  29   }
  30 }
  31
  32 void IPCDataSource::Stop(const base::Closure& callback) {
  33   DCHECK(data_source_thread_checker_.CalledOnValidThread());
  34   callback.Run();
  35 }
  36
  37 void IPCDataSource::Read(int64 position, int size, uint8* data,
  38                          const DataSource::ReadCB& read_cb) {
  39   DCHECK(data_source_thread_checker_.CalledOnValidThread());
  40   utility_task_runner_->PostTask(
  41       FROM_HERE,
  42       base::Bind(&IPCDataSource::ReadOnUtilityThread, base::Unretained(this),
  43                  position, size, data, read_cb));
  44 }
  45
  46 bool IPCDataSource::GetSize(int64* size_out) {
  47   DCHECK(data_source_thread_checker_.CalledOnValidThread());
  48   *size_out = total_size_;
  49   return true;
  50 }
  51
  52 bool IPCDataSource::IsStreaming() {
  53   DCHECK(data_source_thread_checker_.CalledOnValidThread());
  54   return false;
  55 }
  56
  57 void IPCDataSource::SetBitrate(int bitrate) {
  58   DCHECK(data_source_thread_checker_.CalledOnValidThread());
  59 }
  60
  61 bool IPCDataSource::OnMessageReceived(const IPC::Message& message) {
  62   DCHECK(utility_thread_checker_.CalledOnValidThread());
  63   bool handled = true;
  64   IPC_BEGIN_MESSAGE_MAP(IPCDataSource, message)
  65     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_RequestBlobBytes_Finished,
  66                         OnRequestBlobBytesFinished)
  67     IPC_MESSAGE_UNHANDLED(handled = false)
  68   IPC_END_MESSAGE_MAP()
  69   return handled;
  70 }
  71
  72 IPCDataSource::Request::Request()
  73     : destination(NULL) {
  74 }
  75
  76 IPCDataSource::Request::~Request() {
  77 }
  78
  79 void IPCDataSource::ReadOnUtilityThread(int64 position, int size, uint8* data,
  80                                         const DataSource::ReadCB& read_cb) {
  81   DCHECK(utility_thread_checker_.CalledOnValidThread());
  82   CHECK_GE(total_size_, 0);
  83   CHECK_GE(position, 0);
  84   CHECK_GE(size, 0);
  85
  86   // Cap position and size within bounds.
  87   position = std::min(position, total_size_);
  88   int64 clamped_size =
  89       std::min(static_cast<int64>(size), total_size_ - position);
  90
  91   int64 request_id = ++next_request_id_;
  92
  93   Request request;
  94   request.destination = data;
  95   request.callback = read_cb;
  96
  97   pending_requests_[request_id] = request;
  98   content::UtilityThread::Get()->Send(new ChromeUtilityHostMsg_RequestBlobBytes(
  99       request_id, position, clamped_size));
 100 }
 101
 102 void IPCDataSource::OnRequestBlobBytesFinished(int64 request_id,
 103                                                const std::string& bytes) {
 104   DCHECK(utility_thread_checker_.CalledOnValidThread());
 105   std::map<int64, Request>::iterator it = pending_requests_.find(request_id);
 106
 107   if (it == pending_requests_.end())
 108     return;
 109
 110   std::copy(bytes.begin(), bytes.end(), it->second.destination);
 111   it->second.callback.Run(bytes.size());
 112
 113   pending_requests_.erase(it);
 114 }
 115
 116 }  // namespace metadata