private PriorityFrame DecodePriorityFrame(DecodingContext context, int payloadLength, byte flags,
int streamIdentifier)
{
if (streamIdentifier == 0)
{
throw new DecoderException(Http2ErrorCode.ProtocolError, "PRIORITY frames require a stream identifier.");
}
if (payloadLength != 5)
{
throw new DecoderException(Http2ErrorCode.FrameSizeError, "PRIORITY frame payload should be 5 bytes.");
}
var exlusive = (context.Buffer[context.Offset] & Bit32) == Bit32;
var dependency = BitConverter.ToInt32(context.Buffer, context.Offset) & ~Bit32;
var weight = context.Buffer[context.Offset + 4];
context.Offset += 5;
context.BytesLeftToProcess -= 5;
var frame = new PriorityFrame
{
DependencyStreamId = dependency,
Weight = weight,
IsExclusive = exlusive,
StreamIdentifier = streamIdentifier,
FrameFlags = flags
};
return(frame);
}
private void HandlePriority(PriorityFrame priorityFrame, out Http2Stream stream)
{
Http2Logger.LogDebug("PRIORITY frame: stream id={0}, exclusive={1}, dependency={2}, weight={3}",
priorityFrame.StreamId, priorityFrame.Exclusive, priorityFrame.StreamDependency,
priorityFrame.Weight);
/* 12 -> 6.3
* The PRIORITY frame is associated with an existing stream. If a
* PRIORITY frame is received with a stream identifier of 0x0, the
* recipient MUST respond with a connection error of type PROTOCOL_ERROR. */
if (priorityFrame.StreamId == 0)
{
throw new ProtocolError(ResetStatusCode.ProtocolError, "Incoming priority frame with stream id=0");
}
stream = GetStream(priorityFrame.StreamId);
/* 12 -> 6.3
* The PRIORITY frame can be sent on a stream in any of the "reserved
* (remote)", "open", "half-closed (local)", or "half closed (remote)"
* states, though it cannot be sent between consecutive frames that
* comprise a single header block. */
if (stream.Closed)
{
throw new Http2StreamNotFoundException(priorityFrame.StreamId);
}
if (!(stream.Opened || stream.ReservedRemote || stream.HalfClosedLocal))
{
throw new ProtocolError(ResetStatusCode.ProtocolError, "priority for non opened or reserved stream");
}
if (!_usePriorities)
{
return;
}
stream.Priority = priorityFrame.Weight;
}
/// <summary>
/// Process a priority frame request.
/// </summary>
/// <param name="httpContext">The current http context.</param>
/// <param name="priorityFrame">The priority frame.</param>
/// <param name="stream">The selected stream context.</param>
private static void ProcessPriorityFrameRequest(Nequeo.Net.Http2.HttpContext httpContext, PriorityFrame priorityFrame, out ContextStream stream)
{
/* The PRIORITY frame is associated with an existing stream. If a
* PRIORITY frame is received with a stream identifier of 0x0, the
* recipient MUST respond with a connection error of type PROTOCOL_ERROR. */
if (priorityFrame.StreamId == 0)
{
throw new ProtocolError(ErrorCodeRegistry.Protocol_Error, "Incoming priority frame with stream id equal to 0.");
}
// Attempt to get the sepcific stream.
stream = httpContext.GetStream(priorityFrame.StreamId);
if (stream == null)
{
throw new MaxConcurrentStreamsLimitException();
}
/* The PRIORITY frame can be sent on a stream in any of the "reserved
* (remote)", "open", "half-closed (local)", or "half closed (remote)"
* states, though it cannot be sent between consecutive frames that
* comprise a single header block. */
if (stream.Closed)
{
throw new StreamNotFoundException(priorityFrame.StreamId);
}
if (!(stream.Opened || stream.ReservedRemote || stream.HalfClosedLocal))
{
throw new ProtocolError(ErrorCodeRegistry.Protocol_Error, "Priority for non opened or reserved stream.");
}
// If using priorities.
if (httpContext.UsePriorities)
{
// Set the priority weight.
stream.Priority = priorityFrame.Weight;
}
}