Fragmentation support for DataChannel about webrtc-java HOT 2 OPEN

            ByteBuffer buffer = ByteBuffer.allocate(message.length + Integer.BYTES);
            buffer.putInt(message.length).put(message).rewind();

            int chunkSize = 16 * 1024;

            while (buffer.remaining() > 0) {
              var amountToSend = buffer.remaining() <= chunkSize ? buffer.remaining() : chunkSize;
              ByteBuffer part = buffer;

              if (amountToSend != buffer.capacity()) {
                // we need to allocation a new ByteBuffer because send calls ByteBuffer.array()
                // which would return
                // the whole byte[] and not only the slice. But the lib doesn't use
                // ByteBuffer.arrayOffset().
                var slice = buffer.slice(buffer.position(), amountToSend);
                part = ByteBuffer.allocate(amountToSend);
                part.put(slice);
              }

              buffer.position(buffer.position() + amountToSend);
              localDataChannel.send(new RTCDataChannelBuffer(part, true));
              log.debug(prefix() + " sent " + part.capacity() + " bytes");
            }

private ByteBuffer messageBuffer = null;
public final byte[] readMessage(ByteBuffer part) {
    if (messageBuffer == null) {
      int length = part.getInt();
      notifyListeners(Direction.Inbound, State.Start, length, 0);

      if (part.remaining() == length) {
        var ret = new byte[length];
        part.get(ret);
        notifyListeners(Direction.Inbound, State.Complete, length, length);
        return ret;
      }

      messageBuffer = ByteBuffer.allocate(length);
    }

    messageBuffer.put(part);
    notifyListeners(
        Direction.Inbound, State.Progress, messageBuffer.capacity(), messageBuffer.position());

    if (messageBuffer.capacity() == messageBuffer.position()) {
      notifyListeners(
          Direction.Inbound, State.Complete, messageBuffer.capacity(), messageBuffer.capacity());
      var ret = messageBuffer.array();
      messageBuffer = null;
      return ret;
    }

    return null;
  }