WIP - Add EME

media/remoting/remoting_source_impl.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/remoting/remoting_source_impl.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/threading/thread_checker.h"
+
+namespace media {
+
+RemotingSourceImpl::RemotingSourceImpl(
+    mojom::RemotingSourceRequest source_request,
+    mojom::RemoterPtr remoter)
+    : binding_(this, std::move(source_request)), remoter_(std::move(remoter)) {}
+
+RemotingSourceImpl::~RemotingSourceImpl() {
+  if (!clients_.empty()) {
+    UpdateAndNotifyState(RemotingSessionState::SESSION_PERMANENTLY_STOPPED);

[miu, 2016/10/25 04:21:27]

Instead of this, consider calling Shutdown() so that remoter_->Stop() is called
if needed.

[xjz, 2016/10/26 22:00:27]

Done.

+    clients_.clear();
+  }
+}
+
+void RemotingSourceImpl::OnSinkAvailable() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  is_sink_available_ = true;
+  if (state_ == RemotingSessionState::SESSION_UNAVAILABLE)
+    UpdateAndNotifyState(RemotingSessionState::SESSION_CAN_START);
+}
+
+void RemotingSourceImpl::OnSinkGone() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  is_sink_available_ = false;
+  if (state_ == RemotingSessionState::SESSION_PERMANENTLY_STOPPED)
+    return;
+  if (state_ == RemotingSessionState::SESSION_CAN_START) {
+    UpdateAndNotifyState(RemotingSessionState::SESSION_UNAVAILABLE);
+    return;
+  }
+  if (state_ == RemotingSessionState::SESSION_STARTED) {

[miu, 2016/10/25 04:21:27]

Or if in the SESSION_STARTING state too, right?

[xjz, 2016/10/26 22:00:27]

Done.

+    remoter_->Stop(mojom::RemotingStopReason::ROUTE_TERMINATED);

[miu, 2016/10/25 04:21:27]

Actually, you shouldn't need to call Stop() here. OnSinkGone() implies
OnStopped() will be called soon. You could add a helpful comment here like:
"Remoting is being shut down from the other end."

[xjz, 2016/10/26 22:00:27]

Done.

+    UpdateAndNotifyState(RemotingSessionState::SESSION_STOPPING);
+  }
+}
+
+void RemotingSourceImpl::OnStarted() {
+  VLOG(1) << "Remoting started successively.";
+  if (!is_sink_available_ || clients_.empty() ||

[miu, 2016/10/25 04:21:26]

The "!is_sink_available_" shouldn't be needed. (There would be a consistency
problem if OnStarted() were called after OnSinkGone().)

[xjz, 2016/10/26 22:00:27]

Done.

+      state_ == RemotingSessionState::SESSION_PERMANENTLY_STOPPED ||
+      state_ == RemotingSessionState::SESSION_STOPPING) {
+    for (Client* client : clients_)
+      client->OnStarted(false);
+    remoter_->Stop(mojom::RemotingStopReason::ROUTE_TERMINATED);

[miu, 2016/10/25 04:21:27]

The reason should be LOCAL_PLAYBACK since either there are no
RemotingRenderers/CDMs or this current session is permanently stopped.
(ROUTE_TERMINATED was meant for shutting down remoting via the Media Router
dialog.)

[xjz, 2016/10/26 22:00:27]

Done.

+    if (state_ != RemotingSessionState::SESSION_PERMANENTLY_STOPPED)
+      state_ = RemotingSessionState::SESSION_STOPPING;
+    return;
+  }
+  for (Client* client : clients_)
+    client->OnStarted(true);
+  state_ = RemotingSessionState::SESSION_STARTED;
+}
+
+void RemotingSourceImpl::OnStartFailed(mojom::RemotingStartFailReason reason) {
+  VLOG(1) << "Failed to start remoting:" << reason;
+  for (Client* client : clients_)
+    client->OnStarted(false);
+  if (state_ == RemotingSessionState::SESSION_PERMANENTLY_STOPPED)
+    return;
+  state_ = is_sink_available_ ? RemotingSessionState::SESSION_CAN_START

[miu, 2016/10/25 04:21:27]

This should just be "state_ = SESSION_UNAVAILABLE" because is_sink_available_
should always be false at this point. Also, if you look at the possible
RemotingStartFailReasons, you would not want to set "state_ = SESSION_CAN_START"
until OnSinkAvailable() gets called again.

[xjz, 2016/10/26 22:00:27]

Done.

+                              : RemotingSessionState::SESSION_UNAVAILABLE;
+}
+
+void RemotingSourceImpl::OnStopped(mojom::RemotingStopReason reason) {
+  VLOG(1) << "Remoting stopped: " << reason;
+  if (state_ == RemotingSessionState::SESSION_PERMANENTLY_STOPPED)
+    return;
+  RemotingSessionState state = is_sink_available_

[miu, 2016/10/25 04:21:27]

This should just be "state_ = SESSION_UNAVAILABLE" because there will be a later
call to OnSinkAvailable(), and that's where you can set "state_ =
SESSION_CAN_START".

[xjz, 2016/10/26 22:00:27]

Done.

+                                   ? RemotingSessionState::SESSION_CAN_START
+                                   : RemotingSessionState::SESSION_UNAVAILABLE;
+  UpdateAndNotifyState(state);
+}
+
+void RemotingSourceImpl::OnMessageFromSink(
+    const std::vector<uint8_t>& message) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // TODO(xjz): Merge with Eric's CL to handle the RPC messages here.
+  NOTIMPLEMENTED();
+}
+
+void RemotingSourceImpl::UpdateAndNotifyState(RemotingSessionState state) {
+  if (state_ == state)
+    return;
+  state_ = state;
+  for (Client* client : clients_)
+    client->OnSessionStateChanged();
+}
+
+void RemotingSourceImpl::StartRemoting(Client* client) {
+  DCHECK(clients_.find(client) != clients_.end());
+
+  switch (state_) {
+    case SESSION_CAN_START:
+      remoter_->Start();
+      UpdateAndNotifyState(RemotingSessionState::SESSION_STARTING);
+      break;
+    case SESSION_STARTING:
+      break;
+    case SESSION_STARTED:
+      client->OnStarted(true);
+      break;
+    case SESSION_STOPPING:
+    case SESSION_UNAVAILABLE:
+    case SESSION_PERMANENTLY_STOPPED:
+      client->OnStarted(false);
+      break;
+  }
+}
+
+void RemotingSourceImpl::StopRemoting(Client* client) {
+  DCHECK(clients_.find(client) != clients_.end());
+
+  VLOG(1) << "RemotingSourceImpl::StopRemoting: " << state_;
+
+  if (state_ != RemotingSessionState::SESSION_STARTING &&
+      state_ != RemotingSessionState::SESSION_STARTED)
+    return;
+
+  if (state_ == RemotingSessionState::SESSION_STARTED)
+    remoter_->Stop(mojom::RemotingStopReason::LOCAL_PLAYBACK);
+  UpdateAndNotifyState(RemotingSessionState::SESSION_STOPPING);
+}
+
+void RemotingSourceImpl::AddClient(Client* client) {
+  if (clients_.find(client) != clients_.end())
+    return;
+  clients_.insert(client);
+  client->OnSessionStateChanged();
+}
+
+void RemotingSourceImpl::RemoveClient(Client* client) {
+  if (clients_.find(client) == clients_.end())
+    return;
+  clients_.erase(client);
+  if (clients_.empty() && state_ == RemotingSessionState::SESSION_STARTED) {

[miu, 2016/10/25 04:21:27]

Or if in the SESSION_STARTING state too, right?

[xjz, 2016/10/26 22:00:27]

My original thought was to call Stop() in OnStarted() when session is in
SESSION_STARTING state and there is no client, or ShutDown() is called, or
StopRemoting() is called, and is in the SESSION_STARTING state. Now changed to
call Stop() immediately when any of these happen. This might be more readable.

+    remoter_->Stop(mojom::RemotingStopReason::SOURCE_GONE);
+    state_ = RemotingSessionState::SESSION_STOPPING;
+  }
+}
+
+void RemotingSourceImpl::ShutDown() {
+  if (state_ == RemotingSessionState::SESSION_STARTED)

[miu, 2016/10/25 04:21:27]

ditto: We want to call Stop() if SESSION_STARTING.

[xjz, 2016/10/26 22:00:27]

Done.

+    remoter_->Stop(mojom::RemotingStopReason::UNEXPECTED_FAILURE);
+  UpdateAndNotifyState(RemotingSessionState::SESSION_PERMANENTLY_STOPPED);
+}
+
+}  // namespace media