private PushPromise DecodePushPromise(DecodingContext context, int payloadLength, byte flags,
int streamIdentifier)
{
if (streamIdentifier != 0)
{
throw new DecoderException(Http2ErrorCode.ProtocolError,
"PUSH_PROMISE frame must have a stream identifier.");
}
var paddingSize = GetPaddingSize(context, flags);
var promisedStreamId = BitConverter.ToInt32(context.Buffer, context.Offset) & ~Bit32;
context.Offset += 4;
context.BytesLeftToProcess -= 4;
var frame = new PushPromise
{
FrameFlags = flags,
StreamIdentifier = streamIdentifier,
PromisedStreamId = promisedStreamId
};
_headerReceiver = args => frame.Add(args.Name, args.Value, args.IsIndexingAllowed);
_headerDecoder.Decode(context.Buffer, ref context.Offset, ref context.BytesLeftToProcess);
_headerReceiver = null;
// skip padding
context.BytesLeftToProcess -= paddingSize;
context.Offset += paddingSize;
return(frame);
}
private HeaderFrame DecodeHeaderFrame(DecodingContext context, int payloadLength, byte flags,
int streamIdentifier)
{
var paddingSize = GetPaddingSize(context, flags);
var isPriority = (flags & 0x20) == 0x20;
if (isPriority)
{
var isExclusive = (context.Buffer[context.Offset] & Bit32) == Bit32;
var streamDependencyId = BitConverter.ToInt32(context.Buffer, context.Offset) & ~Bit32;
context.Offset += 4;
var weight = context.Buffer[context.Offset++];
context.BytesLeftToProcess -= 5;
}
_headerFrame = new HeaderFrame
{
FrameFlags = flags,
StreamIdentifier = streamIdentifier
};
_headerReceiver = args => _headerFrame.Add(args.Name, args.Value, args.IsIndexingAllowed);
_headerDecoder.Decode(context.Buffer, ref context.Offset, ref context.BytesLeftToProcess);
_headerReceiver = null;
// skip padding
context.BytesLeftToProcess -= paddingSize;
context.Offset += paddingSize;
// A HEADERS frame without the END_HEADERS flag set MUST be followed by a CONTINUATION frame for the same stream
if ((flags & 0x4) == 0x4)
{
_continuationHandlers[streamIdentifier] = ResumeHeaderFrame;
return(null);
}
var frame = _headerFrame;
_headerFrame = null;
return(frame);
}
/// <summary>
/// CONTINUATION frame for the HEADERS frame
/// </summary>
private HttpFrame ResumeHeaderFrame(DecodingContext context, int contentlength, byte flags, int streamIdentifier)
{
if (streamIdentifier == 0)
{
throw new DecoderException(Http2ErrorCode.ProtocolError,
"CONTINUATION frames require a stream identifier.");
}
_headerReceiver = args => _headerFrame.Add(args.Name, args.Value, args.IsIndexingAllowed);
_headerDecoder.Decode(context.Buffer, ref context.Offset, ref context.BytesLeftToProcess);
_headerReceiver = null;
// A HEADERS frame without the END_HEADERS flag set MUST be followed by a CONTINUATION frame for the same stream
if ((flags & 0x4) == 0x4)
{
_continuationHandlers[streamIdentifier] = ResumeHeaderFrame;
return(null);
}
var frame = _headerFrame;
_headerFrame = null;
return(frame);
}
