Support for onbufferedamountlow

talk/app/webrtc/datachannel.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 458 matching lines @@
   }
 }
 
 void DataChannel::SendQueuedDataMessages() {
   if (queued_send_data_.Empty()) {
     return;
   }
 
   ASSERT(state_ == kOpen || state_ == kClosing);
 
+  uint64 start_buffered_amount = buffered_amount();
   while (!queued_send_data_.Empty()) {
     DataBuffer* buffer = queued_send_data_.Front();
     if (!SendDataMessage(*buffer, false)) {
       // Leave the message in the queue if sending is aborted.
       break;
     }
     queued_send_data_.Pop();
     delete buffer;
   }
+
+  if (observer_ && buffered_amount() < start_buffered_amount) {
+    observer_->OnBufferedAmountChange(start_buffered_amount);
+  }
 }
 
 bool DataChannel::SendDataMessage(const DataBuffer& buffer,
                                   bool queue_if_blocked) {
   cricket::SendDataParams send_params;
 
   if (data_channel_type_ == cricket::DCT_SCTP) {
     send_params.ordered = config_.ordered;
     // Send as ordered if it is still going through OPEN/ACK signaling.
     if (handshake_state_ != kHandshakeReady && !config_.ordered) {
@@ skipping 29 matching lines @@
   // Close the channel if the error is not SDR_BLOCK, or if queuing the
   // message failed.
   LOG(LS_ERROR) << "Closing the DataChannel due to a failure to send data, "
                 << "send_result = " << send_result;
   Close();
 
   return false;
 }
 
 bool DataChannel::QueueSendDataMessage(const DataBuffer& buffer) {
-  if (queued_send_data_.byte_count() >= kMaxQueuedSendDataBytes) {
+  size_t start_buffered_amount = buffered_amount();
+  if (start_buffered_amount >= kMaxQueuedSendDataBytes) {
     LOG(LS_ERROR) << "Can't buffer any more data for the data channel.";
     return false;
   }
   queued_send_data_.Push(new DataBuffer(buffer));
+
+  // The buffer can have length zero, in which case there is no change.
+  if (observer_ && buffered_amount() > start_buffered_amount) {
+    observer_->OnBufferedAmountChange(start_buffered_amount);
+  }
   return true;
 }
 
 void DataChannel::SendQueuedControlMessages() {
   PacketQueue control_packets;
   control_packets.Swap(&queued_control_data_);
 
   while (!control_packets.Empty()) {
     rtc::scoped_ptr<DataBuffer> buf(control_packets.Front());
     SendControlMessage(buf->data);
@@ skipping 35 matching lines @@
     QueueControlMessage(buffer);
   } else {
     LOG(LS_ERROR) << "Closing the DataChannel due to a failure to send"
                   << " the CONTROL message, send_result = " << send_result;
     Close();
   }
   return retval;
 }
 
 }  // namespace webrtc