Motown: Framework parts for mojo transport (producer/consumer/mediapipe) and control (audiotrack).

services/media/framework_mojo/push_producer_base.h

+// 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.
+
+#ifndef SERVICES_MEDIA_FRAMEWORK_MOJO_PUSH_PRODUCER_BASE_H_
+#define SERVICES_MEDIA_FRAMEWORK_MOJO_PUSH_PRODUCER_BASE_H_
+
+#include "base/single_thread_task_runner.h"
+#include "base/synchronization/lock.h"
+#include "base/task_runner.h"
+#include "mojo/services/media/common/interfaces/media_pipe.mojom.h"
+#include "mojo/services/media/common/interfaces/media_state.mojom.h"
+#include "services/media/framework/models/active_sink.h"
+#include "services/media/framework_mojo/mojo_allocator.h"
+
+namespace mojo {
+namespace media {
+
+// Abstract base class for push-mode producers.
+// TODO(dalesat): Merge producers once transport definitions are merged.
+class PushProducerBase : public ActiveSink {
+ public:
+  using StatusCallback = std::function<void(MediaState)>;
+
+  PushProducerBase();
+
+  ~PushProducerBase() override;
+
+  // Sets a callback for reporting status updates.
+  void SetStatusCallback(const StatusCallback& callback);
+
+  // ActiveSink implementation.
+  PayloadAllocator* allocator() override;
+
+  void SetDemandCallback(const DemandCallback& demand_callback) override;
+
+  void Prime() override;
+
+  Demand SupplyPacket(PacketPtr packet) override;
+
+ protected:
+  // Overridden in subclasses to verify that the producer is still connected.
+  virtual bool IsConnected() = 0;
+
+  // Overridden in subclasses to push a packet to the consumer/pipe.
+  // packet_raw_ptr should be wrapped in a PacketPtr for proper lifetime
+  // management.
+  // TODO(dalesat): Don't use a raw pointer, if possible.
+  virtual void PushPacketInternal(
+      Packet* packet_raw_ptr,
+      MediaPacketPtr media_packet) = 0;
+
+  // Called by subclasses when a push completes.
+  void PushCompleted(const PacketPtr& packet);
+
+  // Called by subclasses when the connection to the consumer is lost.
+  void OnConnectionLost();
+
+  // Allocates from the shared buffer.
+  MojoAllocator mojo_allocator_;
+
+ private:
+  // Calls PushPacketInternal
+  void PushPacket(
+      Packet* packet_raw_ptr,
+      MediaPacketPtr media_packet);
+
+  // Sets the current state and calls the registered callback, if there is one.
+  void SetState(MediaState state);
+
+  // Creates a MediaPacket from a Packet.
+  MediaPacketPtr CreateMediaPacket(const PacketPtr& packet);
+
+  StatusCallback status_callback_;
+
+  mutable base::Lock lock_;
+  // THE FIELDS BELOW SHOULD ONLY BE ACCESSED WITH lock_ TAKEN.
+  MediaState state_;
+  bool end_of_stream_;
+  DemandCallback demand_callback_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  // TODO(dalesat): Base this logic on presentation time or duration.
+  uint32_t max_pushes_outstanding_;
+  uint32_t current_pushes_outstanding_;
+  // THE FIELDS ABOVE SHOULD ONLY BE ACCESSED WITH lock_ TAKEN.
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif  // SERVICES_MEDIA_FRAMEWORK_MOJO_PUSH_PRODUCER_BASE_H_