Use unique_ptr in DataChannel PacketQueue

Bug: None
Change-Id: I629d42c5a2e736ae352ef5df01eb19b2a9498e7f
Reviewed-on: https://webrtc-review.googlesource.com/c/114261
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Amit Hilbuch <amithi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26008}

pc/datachannel.cc

@@ -12,7 +12,9 @@
 
 #include <memory>
 #include <string>
+#include <utility>
 
+#include "absl/memory/memory.h"
 #include "media/sctp/sctptransportinternal.h"
 #include "pc/sctputils.h"
 #include "rtc_base/checks.h"
@@ -63,39 +65,30 @@ bool SctpSidAllocator::IsSidAvailable(int sid) const {
   return used_sids_.find(sid) == used_sids_.end();
 }
 
-DataChannel::PacketQueue::PacketQueue() : byte_count_(0) {}
-
-DataChannel::PacketQueue::~PacketQueue() {
-  Clear();
-}
-
 bool DataChannel::PacketQueue::Empty() const {
   return packets_.empty();
 }
 
-DataBuffer* DataChannel::PacketQueue::Front() {
-  return packets_.front();
-}
-
-void DataChannel::PacketQueue::Pop() {
-  if (packets_.empty()) {
-    return;
-  }
-
+std::unique_ptr<DataBuffer> DataChannel::PacketQueue::PopFront() {
+  RTC_DCHECK(!packets_.empty());
   byte_count_ -= packets_.front()->size();
+  std::unique_ptr<DataBuffer> packet = std::move(packets_.front());
   packets_.pop_front();
+  return packet;
 }
 
-void DataChannel::PacketQueue::Push(DataBuffer* packet) {
+void DataChannel::PacketQueue::PushFront(std::unique_ptr<DataBuffer> packet) {
   byte_count_ += packet->size();
-  packets_.push_back(packet);
+  packets_.push_front(std::move(packet));
+}
+
+void DataChannel::PacketQueue::PushBack(std::unique_ptr<DataBuffer> packet) {
+  byte_count_ += packet->size();
+  packets_.push_back(std::move(packet));
 }
 
 void DataChannel::PacketQueue::Clear() {
-  while (!packets_.empty()) {
-    delete packets_.front();
-    packets_.pop_front();
-  }
+  packets_.clear();
   byte_count_ = 0;
 }
 
@@ -393,7 +386,7 @@ void DataChannel::OnDataReceived(const cricket::ReceiveDataParams& params,
   }
 
   bool binary = (params.type == cricket::DMT_BINARY);
-  std::unique_ptr<DataBuffer> buffer(new DataBuffer(payload, binary));
+  auto buffer = absl::make_unique<DataBuffer>(payload, binary);
   if (state_ == kOpen && observer_) {
     ++messages_received_;
     bytes_received_ += buffer->size();
@@ -410,7 +403,7 @@ void DataChannel::OnDataReceived(const cricket::ReceiveDataParams& params,
 
       return;
     }
-    queued_received_data_.Push(buffer.release());
+    queued_received_data_.PushBack(std::move(buffer));
   }
 }
 
@@ -541,11 +534,10 @@ void DataChannel::DeliverQueuedReceivedData() {
   }
 
   while (!queued_received_data_.Empty()) {
-    std::unique_ptr<DataBuffer> buffer(queued_received_data_.Front());
+    std::unique_ptr<DataBuffer> buffer = queued_received_data_.PopFront();
     ++messages_received_;
     bytes_received_ += buffer->size();
     observer_->OnMessage(*buffer);
-    queued_received_data_.Pop();
   }
 }
 
@@ -558,13 +550,12 @@ void DataChannel::SendQueuedDataMessages() {
 
   uint64_t start_buffered_amount = buffered_amount();
   while (!queued_send_data_.Empty()) {
-    DataBuffer* buffer = queued_send_data_.Front();
+    std::unique_ptr<DataBuffer> buffer = queued_send_data_.PopFront();
     if (!SendDataMessage(*buffer, false)) {
-      // Leave the message in the queue if sending is aborted.
+      // Return the message to the front of the queue if sending is aborted.
+      queued_send_data_.PushFront(std::move(buffer));
       break;
     }
-    queued_send_data_.Pop();
-    delete buffer;
   }
 
   if (observer_ && buffered_amount() < start_buffered_amount) {
@@ -628,7 +619,7 @@ bool DataChannel::QueueSendDataMessage(const DataBuffer& buffer) {
     RTC_LOG(LS_ERROR) << "Can't buffer any more data for the data channel.";
     return false;
   }
-  queued_send_data_.Push(new DataBuffer(buffer));
+  queued_send_data_.PushBack(absl::make_unique<DataBuffer>(buffer));
 
   // The buffer can have length zero, in which case there is no change.
   if (observer_ && buffered_amount() > start_buffered_amount) {
@@ -642,14 +633,13 @@ void DataChannel::SendQueuedControlMessages() {
   control_packets.Swap(&queued_control_data_);
 
   while (!control_packets.Empty()) {
-    std::unique_ptr<DataBuffer> buf(control_packets.Front());
+    std::unique_ptr<DataBuffer> buf = control_packets.PopFront();
     SendControlMessage(buf->data);
-    control_packets.Pop();
   }
 }
 
 void DataChannel::QueueControlMessage(const rtc::CopyOnWriteBuffer& buffer) {
-  queued_control_data_.Push(new DataBuffer(buffer, true));
+  queued_control_data_.PushBack(absl::make_unique<DataBuffer>(buffer, true));
 }
 
 bool DataChannel::SendControlMessage(const rtc::CopyOnWriteBuffer& buffer) {

pc/datachannel.h

@@ -12,6 +12,7 @@
 #define PC_DATACHANNEL_H_
 
 #include <deque>
+#include <memory>
 #include <set>
 #include <string>
 
@@ -211,28 +212,24 @@ class DataChannel : public DataChannelInterface, public sigslot::has_slots<> {
  private:
   // A packet queue which tracks the total queued bytes. Queued packets are
   // owned by this class.
-  class PacketQueue {
+  class PacketQueue final {
    public:
-    PacketQueue();
-    ~PacketQueue();
-
     size_t byte_count() const { return byte_count_; }
 
     bool Empty() const;
 
-    DataBuffer* Front();
+    std::unique_ptr<DataBuffer> PopFront();
 
-    void Pop();
-
-    void Push(DataBuffer* packet);
+    void PushFront(std::unique_ptr<DataBuffer> packet);
+    void PushBack(std::unique_ptr<DataBuffer> packet);
 
     void Clear();
 
     void Swap(PacketQueue* other);
 
    private:
-    std::deque<DataBuffer*> packets_;
-    size_t byte_count_;
+    std::deque<std::unique_ptr<DataBuffer>> packets_;
+    size_t byte_count_ = 0;
   };
 
   // The OPEN(_ACK) signaling state.