/// <summary>
/// Sends the specified packet to this node asynchronously.
/// The method enqueues a task to write the packet and returns
/// immediately. This is because SendData() is on a hot path
/// under the primary lock (BuildManager's _syncLock)
/// and we want to minimize our time there.
/// </summary>
/// <param name="packet">The packet to send.</param>
public void SendData(INodePacket packet)
{
if (IsExitPacket(packet))
{
_exitPacketState = ExitPacketState.ExitPacketQueued;
}
_packetWriteQueue.Add(packet);
DrainPacketQueue();
}
/// <summary>
/// Actually writes and sends the packet. This can't be called in parallel
/// because it reuses the _writeBufferMemoryStream, and this is why we use
/// the _packetWriteDrainTask to serially chain invocations one after another.
/// </summary>
/// <param name="packet">The packet to send.</param>
private void SendDataCore(INodePacket packet)
{
MemoryStream writeStream = _writeBufferMemoryStream;
// clear the buffer but keep the underlying capacity to avoid reallocations
writeStream.SetLength(0);
ITranslator writeTranslator = BinaryTranslator.GetWriteTranslator(writeStream);
try
{
writeStream.WriteByte((byte)packet.Type);
// Pad for the packet length
WriteInt32(writeStream, 0);
packet.Translate(writeTranslator);
int writeStreamLength = (int)writeStream.Position;
// Now plug in the real packet length
writeStream.Position = 1;
WriteInt32(writeStream, writeStreamLength - 5);
byte[] writeStreamBuffer = writeStream.GetBuffer();
for (int i = 0; i < writeStreamLength; i += MaxPacketWriteSize)
{
int lengthToWrite = Math.Min(writeStreamLength - i, MaxPacketWriteSize);
_serverToClientStream.Write(writeStreamBuffer, i, lengthToWrite);
}
if (IsExitPacket(packet))
{
_exitPacketState = ExitPacketState.ExitPacketSent;
}
}
catch (IOException e)
{
// Do nothing here because any exception will be caught by the async read handler
CommunicationsUtilities.Trace(_nodeId, "EXCEPTION in SendData: {0}", e);
}
catch (ObjectDisposedException) // This happens if a child dies unexpectedly
{
// Do nothing here because any exception will be caught by the async read handler
}
}
