Add VideoProcessor interface.

remoting/client/rectangle_update_decoder.cc

 // Copyright (c) 2012 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 "remoting/client/rectangle_update_decoder.h"
 
+#include <list>
+
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "remoting/base/util.h"
 #include "remoting/client/frame_consumer.h"
 #include "remoting/codec/video_decoder.h"
 #include "remoting/codec/video_decoder_verbatim.h"
@@ skipping 50 matching lines @@
   }
 
   virtual const webrtc::DesktopRegion* GetImageShape() OVERRIDE {
     return parent_->GetImageShape();
   }
 
  private:
   scoped_ptr<VideoDecoder> parent_;
 };
 
-RectangleUpdateDecoder::RectangleUpdateDecoder(
+class RectangleUpdateDecoder::Core : public base::RefCountedThreadSafe<Core> {
+ public:
+  Core(scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+       scoped_refptr<base::SingleThreadTaskRunner> decode_task_runner,
+       scoped_refptr<FrameConsumerProxy> consumer);
+
+  // VideoProcessor implementation.
+  void Initialize(const protocol::SessionConfig& config);
+  ChromotingStats* GetStats();
+  void ProcessVideoPacket(scoped_ptr<VideoPacket> packet,
+                                  const base::Closure& done);
+
+  // FrameProducer implementation.  These methods may be called before we are
+  // Initialize()d, or we know the source screen size.
+  void DrawBuffer(webrtc::DesktopFrame* buffer);
+  void InvalidateRegion(const webrtc::DesktopRegion& region);
+  void RequestReturnBuffers(const base::Closure& done);
+  void SetOutputSizeAndClip(
+      const webrtc::DesktopSize& view_size,
+      const webrtc::DesktopRect& clip_area);
+  const webrtc::DesktopRegion* GetBufferShape();
+
+ private:
+  friend class base::RefCountedThreadSafe<Core>;
+  virtual ~Core();
+
+  // Paints the invalidated region to the next available buffer and returns it
+  // to the consumer.
+  void SchedulePaint();
+  void DoPaint();
+
+  // Decodes the contents of |packet|. DecodePacket may keep a reference to
+  // |packet| so the |packet| must remain alive and valid until |done| is
+  // executed.
+  void DecodePacket(scoped_ptr<VideoPacket> packet, const base::Closure& done);
+
+  // Callback method when a VideoPacket is processed. |decode_start| contains
+  // the timestamp when the packet will start to be processed.
+  void OnPacketDone(base::Time decode_start, const base::Closure& done);
+
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> decode_task_runner_;
+  scoped_refptr<FrameConsumerProxy> consumer_;
+  scoped_ptr<VideoDecoder> decoder_;
+
+  // Remote screen size in pixels.
+  webrtc::DesktopSize source_size_;
+
+  // Vertical and horizontal DPI of the remote screen.
+  webrtc::DesktopVector source_dpi_;
+
+  // The current dimensions of the frame consumer view.
+  webrtc::DesktopSize view_size_;
+  webrtc::DesktopRect clip_area_;
+
+  // The drawing buffers supplied by the frame consumer.
+  std::list<webrtc::DesktopFrame*> buffers_;
+
+  // Flag used to coalesce runs of SchedulePaint()s into a single DoPaint().
+  bool paint_scheduled_;
+
+  ChromotingStats stats_;

[Wez, 2014/01/14 16:23:14]

If you move ProcessVideoPacket and OnDecodeDone back out to
RectangleUpdateDecoder, since they are called on the main thread, then you can
also move |stats_| out there and so avoid some boilerplate in Core.

[Sergey Ulanov, 2014/01/15 00:58:17]

Done.

+
+  // Keep track of the most recent sequence number bounced back from the host.
+  int64 latest_sequence_number_;
+};
+
+RectangleUpdateDecoder::Core::Core(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> decode_task_runner,
     scoped_refptr<FrameConsumerProxy> consumer)
     : main_task_runner_(main_task_runner),
       decode_task_runner_(decode_task_runner),
       consumer_(consumer),
       paint_scheduled_(false),
       latest_sequence_number_(0) {
 }
 
-RectangleUpdateDecoder::~RectangleUpdateDecoder() {
+RectangleUpdateDecoder::Core::~Core() {
 }
 
-void RectangleUpdateDecoder::Initialize(const SessionConfig& config) {
+void RectangleUpdateDecoder::Core::Initialize(const SessionConfig& config) {
   if (!decode_task_runner_->BelongsToCurrentThread()) {

[Wez, 2014/01/14 16:23:14]

Since RUD runs on main thread and RUD::Core on decode thread, why not move the
PostTask out into RUD::Initialize(), to remove the need for the
BelongsToCurrentThread() check and make the thread flow easier to reason about?

[Sergey Ulanov, 2014/01/15 00:58:17]

Done.

     decode_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&RectangleUpdateDecoder::Initialize, this,
+        FROM_HERE, base::Bind(&RectangleUpdateDecoder::Core::Initialize, this,
                               config));
     return;
   }
 
   // Initialize decoder based on the selected codec.
   ChannelConfig::Codec codec = config.video_config().codec;
   if (codec == ChannelConfig::CODEC_VERBATIM) {
     decoder_.reset(new VideoDecoderVerbatim());
   } else if (codec == ChannelConfig::CODEC_VP8) {
     decoder_ = VideoDecoderVpx::CreateForVP8();
   } else if (codec == ChannelConfig::CODEC_VP9) {
     decoder_ = VideoDecoderVpx::CreateForVP9();
   } else {
     NOTREACHED() << "Invalid Encoding found: " << codec;
   }
 
   if (consumer_->GetPixelFormat() == FrameConsumer::FORMAT_RGBA) {
     scoped_ptr<VideoDecoder> wrapper(
         new RgbToBgrVideoDecoderFilter(decoder_.Pass()));
     decoder_ = wrapper.Pass();
   }
 }
 
-void RectangleUpdateDecoder::DecodePacket(scoped_ptr<VideoPacket> packet,
+void RectangleUpdateDecoder::Core::DecodePacket(scoped_ptr<VideoPacket> packet,
                                           const base::Closure& done) {
   DCHECK(decode_task_runner_->BelongsToCurrentThread());
 
   base::ScopedClosureRunner done_runner(done);
 
   bool decoder_needs_reset = false;
   bool notify_size_or_dpi_change = false;
 
   // If the packet includes screen size or DPI information, store them.
   if (packet->format().has_screen_width() &&
@@ skipping 24 matching lines @@
   if (notify_size_or_dpi_change)
     consumer_->SetSourceSize(source_size_, source_dpi_);
 
   if (decoder_->DecodePacket(*packet.get())) {
     SchedulePaint();
   } else {
     LOG(ERROR) << "DecodePacket() failed.";
   }
 }
 
-void RectangleUpdateDecoder::SchedulePaint() {
+void RectangleUpdateDecoder::Core::SchedulePaint() {
   if (paint_scheduled_)
     return;
   paint_scheduled_ = true;
   decode_task_runner_->PostTask(
-      FROM_HERE, base::Bind(&RectangleUpdateDecoder::DoPaint, this));
+      FROM_HERE, base::Bind(&RectangleUpdateDecoder::Core::DoPaint, this));
 }
 
-void RectangleUpdateDecoder::DoPaint() {
+void RectangleUpdateDecoder::Core::DoPaint() {
   DCHECK(paint_scheduled_);
   paint_scheduled_ = false;
 
   // If the view size is empty or we have no output buffers ready, return.
   if (buffers_.empty() || view_size_.is_empty())
     return;
 
   // If no Decoder is initialized, or the host dimensions are empty, return.
   if (!decoder_.get() || source_size_.is_empty())
     return;
 
   // Draw the invalidated region to the buffer.
   webrtc::DesktopFrame* buffer = buffers_.front();
   webrtc::DesktopRegion output_region;
   decoder_->RenderFrame(view_size_, clip_area_,
-                        buffer->data(),
-                        buffer->stride(),
-                        &output_region);
+                        buffer->data(), buffer->stride(), &output_region);
 
   // Notify the consumer that painting is done.
   if (!output_region.is_empty()) {
     buffers_.pop_front();
     consumer_->ApplyBuffer(view_size_, clip_area_, buffer, output_region);
   }
 }
 
-void RectangleUpdateDecoder::RequestReturnBuffers(const base::Closure& done) {
+void RectangleUpdateDecoder::Core::RequestReturnBuffers(
+    const base::Closure& done) {
   if (!decode_task_runner_->BelongsToCurrentThread()) {
     decode_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&RectangleUpdateDecoder::RequestReturnBuffers,
-        this, done));
+        FROM_HERE, base::Bind(
+            &RectangleUpdateDecoder::Core::RequestReturnBuffers, this, done));
     return;
   }
 
   while (!buffers_.empty()) {
     consumer_->ReturnBuffer(buffers_.front());
     buffers_.pop_front();
   }
 
   if (!done.is_null())
     done.Run();
 }
 
-void RectangleUpdateDecoder::DrawBuffer(webrtc::DesktopFrame* buffer) {
+void RectangleUpdateDecoder::Core::DrawBuffer(webrtc::DesktopFrame* buffer) {
   if (!decode_task_runner_->BelongsToCurrentThread()) {
     decode_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&RectangleUpdateDecoder::DrawBuffer,
+        FROM_HERE, base::Bind(&RectangleUpdateDecoder::Core::DrawBuffer,
                               this, buffer));
     return;
   }
 
   DCHECK(clip_area_.width() <= buffer->size().width() &&
          clip_area_.height() <= buffer->size().height());
 
   buffers_.push_back(buffer);
   SchedulePaint();
 }
 
-void RectangleUpdateDecoder::InvalidateRegion(
+void RectangleUpdateDecoder::Core::InvalidateRegion(
     const webrtc::DesktopRegion& region) {
   if (!decode_task_runner_->BelongsToCurrentThread()) {
     decode_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&RectangleUpdateDecoder::InvalidateRegion,
+        FROM_HERE, base::Bind(&RectangleUpdateDecoder::Core::InvalidateRegion,
                               this, region));
     return;
   }
 
   if (decoder_.get()) {
     decoder_->Invalidate(view_size_, region);
     SchedulePaint();
   }
 }
 
-void RectangleUpdateDecoder::SetOutputSizeAndClip(
+void RectangleUpdateDecoder::Core::SetOutputSizeAndClip(
     const webrtc::DesktopSize& view_size,
     const webrtc::DesktopRect& clip_area) {
   if (!decode_task_runner_->BelongsToCurrentThread()) {
     decode_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&RectangleUpdateDecoder::SetOutputSizeAndClip,
-                              this, view_size, clip_area));
+        FROM_HERE,
+        base::Bind(&RectangleUpdateDecoder::Core::SetOutputSizeAndClip,
+                   this, view_size, clip_area));
     return;
   }
 
   // The whole frame needs to be repainted if the scaling factor has changed.
   if (!view_size_.equals(view_size) && decoder_.get()) {
     webrtc::DesktopRegion region;
     region.AddRect(webrtc::DesktopRect::MakeSize(view_size));
     decoder_->Invalidate(view_size, region);
   }
 
@@ skipping 12 matching lines @@
         i = buffers_.erase(i);
       } else {
         ++i;
       }
     }
 
     SchedulePaint();
   }
 }
 
-const webrtc::DesktopRegion* RectangleUpdateDecoder::GetBufferShape() {
+const webrtc::DesktopRegion* RectangleUpdateDecoder::Core::GetBufferShape() {
   return decoder_->GetImageShape();
 }
 
-void RectangleUpdateDecoder::ProcessVideoPacket(scoped_ptr<VideoPacket> packet,
-                                                const base::Closure& done) {
+void RectangleUpdateDecoder::Core::ProcessVideoPacket(
+    scoped_ptr<VideoPacket> packet,
+    const base::Closure& done) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   // If the video packet is empty then drop it. Empty packets are used to
   // maintain activity on the network.
   if (!packet->has_data() || packet->data().size() == 0) {
     done.Run();
     return;
   }
 
   // Add one frame to the counter.
@@ skipping 11 matching lines @@
     base::TimeDelta round_trip_latency =
         base::Time::Now() -
         base::Time::FromInternalValue(packet->client_sequence_number());
     stats_.round_trip_ms()->Record(round_trip_latency.InMilliseconds());
   }
 
   // Measure the latency between the last packet being received and presented.
   base::Time decode_start = base::Time::Now();
 
   base::Closure decode_done = base::Bind(
-      &RectangleUpdateDecoder::OnPacketDone, this, decode_start, done);
+      &RectangleUpdateDecoder::Core::OnPacketDone, this, decode_start, done);

[Wez, 2014/01/14 16:23:14]

You can put all this code in RectangleUpdateDecoder::ProcessVideoPacket, since
it all runs on |main_task_runner_| (though stats will need moving out to
RectangleUpdateDecoder as well).

[Sergey Ulanov, 2014/01/15 00:58:17]

Done.

 
   decode_task_runner_->PostTask(FROM_HERE, base::Bind(
-      &RectangleUpdateDecoder::DecodePacket, this,
+      &RectangleUpdateDecoder::Core::DecodePacket, this,
       base::Passed(&packet), decode_done));
 }
 
-void RectangleUpdateDecoder::OnPacketDone(base::Time decode_start,
-                                          const base::Closure& done) {
+void RectangleUpdateDecoder::Core::OnPacketDone(base::Time decode_start,
+                                                const base::Closure& done) {
   if (!main_task_runner_->BelongsToCurrentThread()) {

[Wez, 2014/01/14 16:23:14]

Since this method just thread-hops back to |main_task_runner_| to update the
stats and then runs |done| there, it would be cleaner to put this on
RectangleUpdateDecoder, to keep a clean separation between |decoder_task_runner|
and |main_task_runner| code. You'd need to PostTask() through a WeakPtr to the
RUD to do that, though.

[Sergey Ulanov, 2014/01/15 00:58:17]

Done.

     main_task_runner_->PostTask(FROM_HERE, base::Bind(
-        &RectangleUpdateDecoder::OnPacketDone, this,
+        &RectangleUpdateDecoder::Core::OnPacketDone, this,
         decode_start, done));
     return;
   }
 
   // Record the latency between the packet being received and presented.
   stats_.video_decode_ms()->Record(
       (base::Time::Now() - decode_start).InMilliseconds());
 
   done.Run();
 }
 
-ChromotingStats* RectangleUpdateDecoder::GetStats() {
+ChromotingStats* RectangleUpdateDecoder::Core::GetStats() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   return &stats_;
 }
 
+RectangleUpdateDecoder::RectangleUpdateDecoder(
+    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> decode_task_runner,
+    scoped_refptr<FrameConsumerProxy> consumer)
+    : core_(new Core(main_task_runner, decode_task_runner, consumer)) {
+}
+
+void RectangleUpdateDecoder::Initialize(const protocol::SessionConfig& config) {
+  core_->Initialize(config);
+}
+
+ChromotingStats* RectangleUpdateDecoder::GetStats() {
+  return core_->GetStats();
+}
+
+void RectangleUpdateDecoder::ProcessVideoPacket(scoped_ptr<VideoPacket> packet,
+                                                const base::Closure& done) {
+  core_->ProcessVideoPacket(packet.Pass(), done);

[Wez, 2014/01/14 16:23:14]

As with Initialize, where we're just proxying calls from the main thread into
the Core on the decode thread, why not just PostTask from the RUD::Foo method to
the RUD::Core::Foo implementation, and avoid the BelongsToCurrentThread check?
Only down-side is that we'll PostTask even if the threads are the same, but that
will never happen in practice, and I suspect the performance hit is negligible
compared to decode.

[Sergey Ulanov, 2014/01/15 00:58:17]

Done.

+}
+
+void RectangleUpdateDecoder::DrawBuffer(webrtc::DesktopFrame* buffer) {
+  core_->DrawBuffer(buffer);
+}
+
+void RectangleUpdateDecoder::InvalidateRegion(
+    const webrtc::DesktopRegion& region) {
+  core_->InvalidateRegion(region);
+}
+
+void RectangleUpdateDecoder::RequestReturnBuffers(const base::Closure& done) {
+  core_->RequestReturnBuffers(done);
+}
+
+void RectangleUpdateDecoder::SetOutputSizeAndClip(
+    const webrtc::DesktopSize& view_size,
+    const webrtc::DesktopRect& clip_area) {
+  core_->SetOutputSizeAndClip(view_size, clip_area);
+}
+
+const webrtc::DesktopRegion* RectangleUpdateDecoder::GetBufferShape() {
+  return core_->GetBufferShape();
+}
+
+
 }  // namespace remoting