/// <summary>
/// Handle a control message.
/// </summary>
/// <param name="packet">The packet containing the control message.</param>
/// <param name="messageId">The ID of the control message.</param>
/// <returns>True if this ended a frame and requires a flush. An end frame message may be processed without a
/// flush.</returns>
/// <remarks>
/// This method may modify the packet data before it is queued for processing. The primary
/// use case is to write the current frame number into and end of frame message.
/// </remarks>
private bool HandleControlMessage(PacketBuffer packet, ControlMessageID messageId)
{
bool frameFlush = false;
ControlMessage msg = new ControlMessage();
if (!msg.Peek(packet))
{
return(frameFlush);
}
if (messageId == ControlMessageID.EndFrame)
{
// Replace the end of frame packet with a new one including the current frame number.
bool flush = OnEndFrame(msg.Value32);
// Overwrite msg.Value64 with the current frame number.
int memberOffset = PacketHeader.Size + Marshal.OffsetOf(typeof(ControlMessage), "Value64").ToInt32();
byte[] packetData = packet.Data;
byte[] frameNumberBytes = BitConverter.GetBytes(Endian.ToNetwork((ulong)_currentFrame));
Array.Copy(frameNumberBytes, 0, packetData, memberOffset, frameNumberBytes.Length);
// Override the flags to include the flush value.
if (flush)
{
memberOffset = PacketHeader.Size + Marshal.OffsetOf(typeof(ControlMessage), "ControlFlags").ToInt32();
uint controlFlags = BitConverter.ToUInt32(packetData, memberOffset);
controlFlags = Endian.FromNetwork(controlFlags);
// Add the flush flag
controlFlags |= (uint)EndFrameFlag.Flush;
// Convert back to bytes and copy into the packet buffer.
frameNumberBytes = BitConverter.GetBytes(Endian.ToNetwork(controlFlags));
Array.Copy(frameNumberBytes, 0, packetData, memberOffset, frameNumberBytes.Length);
}
frameFlush = !_catchingUp && flush;
}
else if (messageId == ControlMessageID.FrameCount)
{
// Set the frame count.
lock (this)
{
// Only set if current value is less than the read value. This caters for
// badly saved files, where the frame count was improperly finalised.
if (_totalFrames < msg.Value32)
{
_totalFrames = msg.Value32;
}
}
}
return(frameFlush);
}
/// <summary>
/// Handle a control message.
/// </summary>
/// <param name="packet">The packet containing the control message.</param>
/// <param name="messageId">The ID of the control message.</param>
/// <returns>True if this ended a frame.</returns>
/// <remarks>
/// This method may modify the packet data before it is queued for processing. The primary
/// use case is to write the current frame number into and end of frame message.
/// </remarks>
private bool HandleControlMessage(PacketBuffer packet, ControlMessageID messageId)
{
bool endedFrame = false;
ControlMessage msg = new ControlMessage();
if (!msg.Peek(packet))
{
return(endedFrame);
}
if (messageId == ControlMessageID.EndFrame)
{
// Replace the end of frame packet with a new one including the current frame number.
// FIXME: modify the target value in the buffer stream instead of replacing the object.
OnEndFrame(msg.Value32);
// Overwrite msg.Value64 with the current frame number.
int value64Offset = PacketHeader.Size + Marshal.OffsetOf(typeof(ControlMessage), "Value64").ToInt32();
byte[] packetData = packet.Data;
byte[] frameNumberBytes = BitConverter.GetBytes(Endian.ToNetwork((ulong)_currentFrame));
Array.Copy(frameNumberBytes, 0, packetData, value64Offset, frameNumberBytes.Length);
endedFrame = true;
}
else if (messageId == ControlMessageID.FrameCount)
{
// Set the frame count.
lock (this)
{
// Only set if current value is less than the read value. This caters for
// badly saved files, where the frame count was improperly finalised.
if (_totalFrames < msg.Value32)
{
_totalFrames = msg.Value32;
}
}
}
return(endedFrame);
}