public void AbortPendingStreamDataWrites(Http2StreamOutputFlowControl flowControl)
{
lock (_writeLock)
{
flowControl.Abort();
}
}
public bool TryUpdateStreamWindow(Http2StreamOutputFlowControl flowControl, int bytes)
{
lock (_writeLock)
{
return(flowControl.TryUpdateWindow(bytes));
}
}
public Http2Stream(Http2StreamContext context)
: base(context)
{
_context = context;
_outputFlowControl = new Http2StreamOutputFlowControl(context.ConnectionOutputFlowControl, context.ClientPeerSettings.InitialWindowSize);
Output = new Http2OutputProducer(context.StreamId, context.FrameWriter, _outputFlowControl, context.TimeoutControl, context.MemoryPool);
}
public Http2OutputProducer(
int streamId,
Http2FrameWriter frameWriter,
Http2StreamOutputFlowControl flowControl,
ITimeoutControl timeoutControl,
MemoryPool <byte> pool)
{
_streamId = streamId;
_frameWriter = frameWriter;
_flowControl = flowControl;
_dataPipe = CreateDataPipe(pool);
_flusher = new StreamSafePipeFlusher(_dataPipe.Writer, timeoutControl);
_dataWriteProcessingTask = ProcessDataWrites();
}
private async Task WriteDataAsyncAwaited(int streamId, Http2StreamOutputFlowControl flowControl, ReadOnlySequence <byte> data, long dataLength, bool endStream)
{
while (dataLength > 0)
{
Http2OutputFlowControlAwaitable availabilityAwaitable;
var writeTask = Task.CompletedTask;
lock (_writeLock)
{
if (_completed || flowControl.IsAborted)
{
break;
}
var actual = flowControl.AdvanceUpToAndWait(dataLength, out availabilityAwaitable);
if (actual > 0)
{
if (actual < dataLength)
{
writeTask = WriteDataUnsynchronizedAsync(streamId, data.Slice(0, actual), endStream: false);
data = data.Slice(actual);
dataLength -= actual;
}
else
{
writeTask = WriteDataUnsynchronizedAsync(streamId, data, endStream);
dataLength = 0;
}
}
}
// This awaitable releases continuations in FIFO order when the window updates.
// It should be very rare for a continuation to run without any availability.
if (availabilityAwaitable != null)
{
await availabilityAwaitable;
}
await writeTask;
}
// Ensure that the application continuation isn't executed inline by ProcessWindowUpdateFrameAsync.
await ThreadPoolAwaitable.Instance;
}
public Task WriteDataAsync(int streamId, Http2StreamOutputFlowControl flowControl, ReadOnlySequence <byte> data, bool endStream)
{
// The Length property of a ReadOnlySequence can be expensive, so we cache the value.
var dataLength = data.Length;
lock (_writeLock)
{
if (_completed || flowControl.IsAborted)
{
return(Task.CompletedTask);
}
// Zero-length data frames are allowed to be sent immediately even if there is no space available in the flow control window.
// https://httpwg.org/specs/rfc7540.html#rfc.section.6.9.1
if (dataLength != 0 && dataLength > flowControl.Available)
{
return(WriteDataAsyncAwaited(streamId, flowControl, data, dataLength, endStream));
}
// This cast is safe since if dataLength would overflow an int, it's guaranteed to be greater than the available flow control window.
flowControl.Advance((int)dataLength);
return(WriteDataUnsynchronizedAsync(streamId, data, endStream));
}
}
