public async Task <Frame> ReadFrameAsync(CancellationToken cancellationToken)
{
// First read the frame headers, which should tell us how long the rest of the frame is.
byte[] headerBytes = new byte[Frame.FrameHeaderLength];
try
{
if (!await FillBufferAsync(headerBytes, cancellationToken).ConfigureAwait(false))
{
return(null);
}
}
catch (IOException)
{
// eat errors when client aborts connection and return null.
return(null);
}
Frame header = Frame.ReadFrom(headerBytes);
// Read the data segment of the frame, if it is present.
byte[] data = new byte[header.Length];
if (header.Length > 0 && !await FillBufferAsync(data, cancellationToken).ConfigureAwait(false))
{
throw new Exception("Connection stream closed while attempting to read frame body.");
}
if (_ignoredSettingsAckPromise != null && header.Type == FrameType.Settings && header.Flags == FrameFlags.Ack)
{
_ignoredSettingsAckPromise.TrySetResult(true);
_ignoredSettingsAckPromise = null;
return(await ReadFrameAsync(cancellationToken).ConfigureAwait(false));
}
if (_ignoreWindowUpdates && header.Type == FrameType.WindowUpdate)
{
return(await ReadFrameAsync(cancellationToken).ConfigureAwait(false));
}
if (header.Type == FrameType.Ping && _transparentPingResponse)
{
PingFrame pingFrame = PingFrame.ReadFrom(header, data);
bool processed = await TryProcessExpectedPingFrameAsync(pingFrame);
return(processed ? await ReadFrameAsync(cancellationToken).ConfigureAwait(false) : pingFrame);
}
// Construct the correct frame type and return it.
switch (header.Type)
{
case FrameType.Settings:
return(SettingsFrame.ReadFrom(header, data));
case FrameType.Data:
return(DataFrame.ReadFrom(header, data));
case FrameType.Headers:
return(HeadersFrame.ReadFrom(header, data));
case FrameType.Priority:
return(PriorityFrame.ReadFrom(header, data));
case FrameType.RstStream:
return(RstStreamFrame.ReadFrom(header, data));
case FrameType.Ping:
return(PingFrame.ReadFrom(header, data));
case FrameType.GoAway:
return(GoAwayFrame.ReadFrom(header, data));
case FrameType.Continuation:
return(ContinuationFrame.ReadFrom(header, data));
case FrameType.WindowUpdate:
return(WindowUpdateFrame.ReadFrom(header, data));
default:
return(header);
}
}
private async Task <Frame> ReadFrameAsync(CancellationToken cancellationToken)
{
// First read the frame headers, which should tell us how long the rest of the frame is.
byte[] headerBytes = new byte[Frame.FrameHeaderLength];
try
{
if (!await FillBufferAsync(headerBytes, cancellationToken).ConfigureAwait(false))
{
return(null);
}
}
catch (IOException)
{
// eat errors when client aborts connection and return null.
return(null);
}
Frame header = Frame.ReadFrom(headerBytes);
// Read the data segment of the frame, if it is present.
byte[] data = new byte[header.Length];
if (header.Length > 0 && !await FillBufferAsync(data, cancellationToken).ConfigureAwait(false))
{
throw new Exception("Connection stream closed while attempting to read frame body.");
}
if (_ignoreSettingsAck && header.Type == FrameType.Settings && header.Flags == FrameFlags.Ack)
{
_ignoreSettingsAck = false;
return(await ReadFrameAsync(cancellationToken).ConfigureAwait(false));
}
if (_ignoreWindowUpdates && header.Type == FrameType.WindowUpdate)
{
return(await ReadFrameAsync(cancellationToken).ConfigureAwait(false));
}
// Construct the correct frame type and return it.
switch (header.Type)
{
case FrameType.Settings:
return(SettingsFrame.ReadFrom(header, data));
case FrameType.Data:
return(DataFrame.ReadFrom(header, data));
case FrameType.Headers:
return(HeadersFrame.ReadFrom(header, data));
case FrameType.Priority:
return(PriorityFrame.ReadFrom(header, data));
case FrameType.RstStream:
return(RstStreamFrame.ReadFrom(header, data));
case FrameType.Ping:
return(PingFrame.ReadFrom(header, data));
case FrameType.GoAway:
return(GoAwayFrame.ReadFrom(header, data));
default:
return(header);
}
}