PacketBuffer is now ref counted.

webrtc/modules/video_coding/packet_buffer.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
 #define WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
 
 #include <vector>
+#include <memory>
 
 #include "webrtc/base/criticalsection.h"
+#include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/modules/video_coding/packet.h"
 #include "webrtc/modules/video_coding/rtp_frame_reference_finder.h"
 #include "webrtc/modules/video_coding/sequence_number_util.h"
 
 namespace webrtc {
 
 class Clock;
 
 namespace video_coding {
 
 class FrameObject;
 class RtpFrameObject;
 
-class OnCompleteFrameCallback {
+// A received frame is a frame which has received all its packets.
+class OnReceivedFrameCallback {
  public:
-  virtual ~OnCompleteFrameCallback() {}
-  virtual void OnCompleteFrame(std::unique_ptr<FrameObject> frame) = 0;
+  virtual ~OnReceivedFrameCallback() {}
+  virtual void OnReceivedFrame(std::unique_ptr<RtpFrameObject> frame) = 0;
 };
 
 class PacketBuffer {
  public:
+  static rtc::scoped_refptr<PacketBuffer> Create(
+      Clock* clock,
+      size_t start_buffer_size,
+      size_t max_buffer_size,
+      OnReceivedFrameCallback* frame_callback);
+
+  virtual ~PacketBuffer();
+
+  // Made virtual for testing.
+  virtual bool InsertPacket(const VCMPacket& packet);
+  void ClearTo(uint16_t seq_num);
+  void Clear();
+
+  int AddRef() const;
+  int Release() const;
+
+ protected:
   // Both |start_buffer_size| and |max_buffer_size| must be a power of 2.
   PacketBuffer(Clock* clock,
                size_t start_buffer_size,
                size_t max_buffer_size,
-               OnCompleteFrameCallback* frame_callback);
-
-  bool InsertPacket(const VCMPacket& packet);
-  void ClearTo(uint16_t seq_num);
-  void Clear();
+               OnReceivedFrameCallback* frame_callback);
 
  private:
   friend RtpFrameObject;
   // Since we want the packet buffer to be as packet type agnostic
   // as possible we extract only the information needed in order
   // to determine whether a sequence of packets is continuous or not.
   struct ContinuityInfo {
     // The sequence number of the packet.
     uint16_t seq_num = 0;
 
@@ skipping 19 matching lines @@
   bool ExpandBufferSize() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Test if all previous packets has arrived for the given sequence number.
   bool IsContinuous(uint16_t seq_num) const EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Test if all packets of a frame has arrived, and if so, creates a frame.
   // May create multiple frames per invocation.
   void FindFrames(uint16_t seq_num) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Copy the bitstream for |frame| to |destination|.
-  bool GetBitstream(const RtpFrameObject& frame, uint8_t* destination);
+  // Virtual for testing.
+  virtual bool GetBitstream(const RtpFrameObject& frame, uint8_t* destination);
 
   // Get the packet with sequence number |seq_num|.
-  VCMPacket* GetPacket(uint16_t seq_num);
+  // Virtual for testing.
+  virtual VCMPacket* GetPacket(uint16_t seq_num);
 
   // Mark all slots used by |frame| as not used.
-  void ReturnFrame(RtpFrameObject* frame);
+  // Virtual for testing.
+  virtual void ReturnFrame(RtpFrameObject* frame);
 
   rtc::CriticalSection crit_;
 
   // Buffer size_ and max_size_ must always be a power of two.
   size_t size_ GUARDED_BY(crit_);
   const size_t max_size_;
 
   // The fist sequence number currently in the buffer.
   uint16_t first_seq_num_ GUARDED_BY(crit_);
 
   // The last sequence number currently in the buffer.
   uint16_t last_seq_num_ GUARDED_BY(crit_);
 
   // If the packet buffer has received its first packet.
   bool first_packet_received_ GUARDED_BY(crit_);
 
   // Buffer that holds the inserted packets.
   std::vector<VCMPacket> data_buffer_ GUARDED_BY(crit_);
 
   // Buffer that holds the information about which slot that is currently in use
   // and information needed to determine the continuity between packets.
   std::vector<ContinuityInfo> sequence_buffer_ GUARDED_BY(crit_);
 
-  // Frames that have received all their packets are handed off to the
-  // |reference_finder_| which finds the dependencies between the frames.
-  RtpFrameReferenceFinder reference_finder_;
+  // Called when a received frame is found.
+  OnReceivedFrameCallback* const received_frame_callback_;
+
+  mutable volatile int ref_count_ = 0;
 };
 
 }  // namespace video_coding
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_