Added cluster id to PacedSender::Callback::TimeToSendPacket.

webrtc/modules/pacing/paced_sender.cc

Index: webrtc/modules/pacing/paced_sender.cc
diff --git a/webrtc/modules/pacing/paced_sender.cc b/webrtc/modules/pacing/paced_sender.cc
index b56d28510f2dc7c6cd377076506da81b987fd09f..55f3972dcb74205b2ba824a5218ad0d228e849aa 100644
--- a/webrtc/modules/pacing/paced_sender.cc
+++ b/webrtc/modules/pacing/paced_sender.cc
@@ -47,7 +47,8 @@ struct Packet {
          int64_t enqueue_time_ms,
          size_t length_in_bytes,
          bool retransmission,
-         uint64_t enqueue_order)
+         uint64_t enqueue_order,
+         int cluster_id = -1)

[danilchap, 2016/05/10 15:31:39]

try to avoid default arguments. Here it is easy: constructor is called just once
and the -1 value could be added there, into InsertPacket function.
Or, if there is no plan to know cluster_id when you create Packet object, just
do not have this parameter and initialized cluster_id member with a constant.

[philipel, 2016/05/11 09:39:16]

Removed default argument, |cluster_id| is not initialized to -1.

       : priority(priority),
         ssrc(ssrc),
         sequence_number(seq_number),
@@ -55,7 +56,8 @@ struct Packet {
         enqueue_time_ms(enqueue_time_ms),
         bytes(length_in_bytes),
         retransmission(retransmission),
-        enqueue_order(enqueue_order) {}
+        enqueue_order(enqueue_order),
+        cluster_id(cluster_id) {}
 
   RtpPacketSender::Priority priority;
   uint32_t ssrc;
@@ -66,6 +68,7 @@ struct Packet {
   bool retransmission;
   uint64_t enqueue_order;
   std::list<Packet>::iterator this_it;
+  int cluster_id;

[danilchap, 2016/05/10 15:31:39]

may be instead of modifying Packet structure, using non-const Pop, unrecommended
default argument, etc. it would be easier to add an argument to SendPacket
function: cluster_id is not really property of a packet but property of the
current state when packet is sent.

[philipel, 2016/05/11 09:39:16]

I agree, removed |cluster_id| From Packet class.

 };
 
 // Used by priority queue to sort packets.
@@ -113,8 +116,8 @@ class PacketQueue {
     bytes_ += packet.bytes;
   }
 
-  const Packet& BeginPop() {
-    const Packet& packet = *prio_queue_.top();
+  Packet& BeginPop() {

[danilchap, 2016/05/10 15:31:39]

If you want return a non-const object, return a pointer instead of reference.

[philipel, 2016/05/11 09:39:16]

True, but now it's const again :)

+    Packet& packet = *prio_queue_.top();
     prio_queue_.pop();
     return packet;
   }
@@ -389,7 +392,9 @@ void PacedSender::Process() {
     // Since we need to release the lock in order to send, we first pop the
     // element from the priority queue but keep it in storage, so that we can
     // reinsert it if send fails.
-    const paced_sender::Packet& packet = packets_->BeginPop();
+    paced_sender::Packet& packet = packets_->BeginPop();
+    if (prober_->IsProbing())
+      packet.cluster_id = prober_->CurrentClusterId();

[danilchap, 2016/05/10 15:31:39]

should you clear cluster_id if not probing? Either here or before calling
CancelPop.

 
     if (SendPacket(packet)) {
       // Send succeeded, remove it from the queue.
@@ -425,10 +430,9 @@ bool PacedSender::SendPacket(const paced_sender::Packet& packet) {
   if (paused_ && packet.priority != kHighPriority)
     return false;
   critsect_->Leave();
-  const bool success = callback_->TimeToSendPacket(packet.ssrc,
-                                                   packet.sequence_number,
-                                                   packet.capture_time_ms,
-                                                   packet.retransmission);
+  const bool success = callback_->TimeToSendPacket(
+      packet.ssrc, packet.sequence_number, packet.capture_time_ms,
+      packet.retransmission, packet.cluster_id);
   critsect_->Enter();
 
   if (success) {