/// <inheritdoc />
public override void Complete(Exception exception = null)
{
if (_isCompleted)
{
return;
}
_isCompleted = true;
_internalTokenSource?.Dispose();
BufferSegment segment = _head;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
returnSegment.ResetMemory();
}
_head = null;
_tail = null;
// REVIEW: Do we need a leaveOpen to avoid this?
InnerStream.Dispose();
}
private void CompletePipe()
{
lock (_sync)
{
if (_disposed)
{
return;
}
_disposed = true;
// Return all segments
// if _readHead is null we need to try return _commitHead
// because there might be a block allocated for writing
BufferSegment segment = _readHead ?? _commitHead;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
returnSegment.ResetMemory();
}
_writingHead = null;
_readHead = null;
_commitHead = null;
}
}
private void FlushInternal(bool writeToStream)
{
// Write all completed segments and whatever remains in the current segment
// and flush the result.
if (_tailBytesBuffered > 0)
{
Debug.Assert(_tail != null);
// Update any buffered data
_tail.End += _tailBytesBuffered;
_tailBytesBuffered = 0;
}
BufferSegment?segment = _head;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
if (returnSegment.Length > 0 && writeToStream)
{
#if (!NETSTANDARD2_0 && !NETFRAMEWORK)
InnerStream.Write(returnSegment.Memory.Span);
#else
InnerStream.Write(returnSegment.Memory);
#endif
}
returnSegment.ResetMemory();
ReturnSegmentUnsynchronized(returnSegment);
// Update the head segment after we return the current segment
_head = segment;
}
if (_bytesBuffered > 0 && writeToStream)
{
InnerStream.Flush();
}
// Mark bytes as written *after* flushing
_head = null;
_tail = null;
_tailMemory = default;
_bytesBuffered = 0;
}
private void FlushInternal()
{
// Write all completed segments and whatever remains in the current segment
// and flush the result.
if (_tailBytesBuffered > 0)
{
// Update any buffered data
_tail.End += _tailBytesBuffered;
_tailBytesBuffered = 0;
}
BufferSegment segment = _head;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
if (returnSegment.Length > 0)
{
#if netcoreapp
InnerStream.Write(returnSegment.Memory.Span);
#else
InnerStream.Write(returnSegment.Memory);
#endif
}
returnSegment.ResetMemory();
ReturnSegmentUnsynchronized(returnSegment);
// Update the head segment after we return the current segment
_head = segment;
}
if (_bytesBuffered > 0)
{
InnerStream.Flush();
}
// Mark bytes as written *after* flushing
_head = null;
_tail = null;
_bytesBuffered = 0;
}
private bool CompleteAndGetNeedsDispose()
{
if (_isReaderCompleted)
{
return(false);
}
_isReaderCompleted = true;
BufferSegment?segment = _readHead;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
returnSegment.ResetMemory();
}
return(!LeaveOpen);
}
/// <inheritdoc />
public override void Complete(Exception exception = null)
{
if (_isReaderCompleted)
{
return;
}
_isReaderCompleted = true;
BufferSegment segment = _readHead;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
returnSegment.ResetMemory();
}
// REVIEW: Do we need a way to avoid this (leaveOpen?)
InnerStream.Dispose();
}
/// <inheritdoc />
public override void Complete(Exception?exception = null)
{
if (_isReaderCompleted)
{
return;
}
_isReaderCompleted = true;
BufferSegment?segment = _readHead;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
returnSegment.ResetMemory();
}
if (!LeaveOpen)
{
InnerStream.Dispose();
}
}
private void AdvanceTo(BufferSegment?consumedSegment, int consumedIndex, BufferSegment?examinedSegment, int examinedIndex)
{
if (consumedSegment == null || examinedSegment == null)
{
return;
}
if (_readHead == null)
{
ThrowHelper.ThrowInvalidOperationException_AdvanceToInvalidCursor();
}
BufferSegment returnStart = _readHead;
BufferSegment?returnEnd = consumedSegment;
long consumedBytes = BufferSegment.GetLength(returnStart, _readIndex, consumedSegment, consumedIndex);
_bufferedBytes -= consumedBytes;
Debug.Assert(_bufferedBytes >= 0);
_examinedEverything = false;
if (examinedSegment == _readTail)
{
// If we examined everything, we force ReadAsync to actually read from the underlying stream
// instead of returning a ReadResult from TryRead.
_examinedEverything = examinedIndex == _readTail.End;
}
// Two cases here:
// 1. All data is consumed. If so, we empty clear everything so we don't hold onto any
// excess memory.
// 2. A segment is entirely consumed but there is still more data in nextSegments
// We are allowed to remove an extra segment. by setting returnEnd to be the next block.
// 3. We are in the middle of a segment.
// Move _readHead and _readIndex to consumedSegment and index
if (_bufferedBytes == 0)
{
returnEnd = null;
_readHead = null;
_readTail = null;
_readIndex = 0;
}
else if (consumedIndex == returnEnd.Length)
{
BufferSegment?nextBlock = returnEnd.NextSegment;
_readHead = nextBlock;
_readIndex = 0;
returnEnd = nextBlock;
}
else
{
_readHead = consumedSegment;
_readIndex = consumedIndex;
}
// Remove all blocks that are freed (except the last one)
while (returnStart != returnEnd)
{
BufferSegment next = returnStart.NextSegment !;
returnStart.ResetMemory();
ReturnSegmentUnsynchronized(returnStart);
returnStart = next;
}
}
private async ValueTask <FlushResult> FlushAsyncInternal(bool writeToStream, ReadOnlyMemory <byte> data, CancellationToken cancellationToken = default)
{
// Write all completed segments and whatever remains in the current segment
// and flush the result.
CancellationTokenRegistration reg = default;
if (cancellationToken.CanBeCanceled)
{
reg = cancellationToken.UnsafeRegister(state => ((StreamPipeWriter)state !).Cancel(), this);
}
if (_tailBytesBuffered > 0)
{
Debug.Assert(_tail != null);
// Update any buffered data
_tail.End += _tailBytesBuffered;
_tailBytesBuffered = 0;
}
using (reg)
{
CancellationToken localToken = InternalTokenSource.Token;
try
{
BufferSegment?segment = _head;
while (segment != null)
{
BufferSegment returnSegment = segment;
segment = segment.NextSegment;
if (returnSegment.Length > 0 && writeToStream)
{
await InnerStream.WriteAsync(returnSegment.Memory, localToken).ConfigureAwait(false);
}
returnSegment.ResetMemory();
ReturnSegmentUnsynchronized(returnSegment);
// Update the head segment after we return the current segment
_head = segment;
}
if (writeToStream)
{
// Write data after the buffered data
if (data.Length > 0)
{
await InnerStream.WriteAsync(data, localToken).ConfigureAwait(false);
}
if (_bytesBuffered > 0 || data.Length > 0)
{
await InnerStream.FlushAsync(localToken).ConfigureAwait(false);
}
}
// Mark bytes as written *after* flushing
_head = null;
_tail = null;
_tailMemory = default;
_bytesBuffered = 0;
return(new FlushResult(isCanceled: false, isCompleted: false));
}
catch (OperationCanceledException)
{
// Remove the cancellation token such that the next time Flush is called
// A new CTS is created.
lock (_lockObject)
{
_internalTokenSource = null;
}
if (localToken.IsCancellationRequested && !cancellationToken.IsCancellationRequested)
{
// Catch cancellation and translate it into setting isCanceled = true
return(new FlushResult(isCanceled: true, isCompleted: false));
}
throw;
}
}
}
internal void Advance(Position consumed, Position examined)
{
BufferSegment returnStart = null;
BufferSegment returnEnd = null;
// Reading commit head shared with writer
Action continuation = null;
lock (_sync)
{
bool examinedEverything = false;
if (examined.Segment == _commitHead)
{
examinedEverything = _commitHead != null ? examined.Index == _commitHeadIndex - _commitHead.Start : examined.Index == 0;
}
if (consumed.Segment != null)
{
if (_readHead == null)
{
PipelinesThrowHelper.ThrowInvalidOperationException(ExceptionResource.AdvanceToInvalidCursor);
return;
}
var consumedSegment = (BufferSegment)consumed.Segment;
returnStart = _readHead;
returnEnd = consumedSegment;
// Check if we crossed _maximumSizeLow and complete backpressure
var consumedBytes = new ReadOnlyBuffer <byte>(returnStart, _readHeadIndex, consumedSegment, consumed.Index).Length;
var oldLength = _length;
_length -= consumedBytes;
if (oldLength >= _maximumSizeLow &&
_length < _maximumSizeLow)
{
continuation = _writerAwaitable.Complete();
}
// Check if we consumed entire last segment
// if we are going to return commit head
// we need to check that there is no writing operation that
// might be using tailspace
if (consumed.Index == returnEnd.Length &&
!(_commitHead == returnEnd && _writingState.IsStarted))
{
var nextBlock = returnEnd.NextSegment;
if (_commitHead == returnEnd)
{
_commitHead = nextBlock;
_commitHeadIndex = 0;
}
_readHead = nextBlock;
_readHeadIndex = 0;
returnEnd = nextBlock;
}
else
{
_readHead = consumedSegment;
_readHeadIndex = consumed.Index;
}
}
// We reset the awaitable to not completed if we've examined everything the producer produced so far
// but only if writer is not completed yet
if (examinedEverything && !_writerCompletion.IsCompleted)
{
// Prevent deadlock where reader awaits new data and writer await backpressure
if (!_writerAwaitable.IsCompleted)
{
PipelinesThrowHelper.ThrowInvalidOperationException(ExceptionResource.BackpressureDeadlock);
}
_readerAwaitable.Reset();
}
_readingState.End(ExceptionResource.NoReadToComplete);
while (returnStart != null && returnStart != returnEnd)
{
returnStart.ResetMemory();
ReturnSegmentUnsynchronized(returnStart);
returnStart = returnStart.NextSegment;
}
}
TrySchedule(_writerScheduler, continuation);
}
internal void AdvanceReader(SequencePosition consumed, SequencePosition examined)
{
BufferSegment returnStart = null;
BufferSegment returnEnd = null;
Action continuation = null;
lock (_sync)
{
var examinedEverything = false;
if (examined.GetObject() == _commitHead)
{
examinedEverything = _commitHead != null?examined.GetInteger() == _commitHeadIndex - _commitHead.Start : examined.GetInteger() == 0;
}
if (consumed.GetObject() != null)
{
if (_readHead == null)
{
ThrowHelper.ThrowInvalidOperationException_AdvanceToInvalidCursor();
return;
}
var consumedSegment = (BufferSegment)consumed.GetObject();
returnStart = _readHead;
returnEnd = consumedSegment;
// Check if we crossed _maximumSizeLow and complete backpressure
long consumedBytes = new ReadOnlySequence <byte>(returnStart, _readHeadIndex, consumedSegment, consumed.GetInteger()).Length;
long oldLength = _length;
_length -= consumedBytes;
if (oldLength >= _resumeWriterThreshold &&
_length < _resumeWriterThreshold)
{
continuation = _writerAwaitable.Complete();
}
// Check if we consumed entire last segment
// if we are going to return commit head we need to check that there is no writing operation that
// might be using tailspace
if (consumed.GetInteger() == returnEnd.Length && _writingHead != returnEnd)
{
BufferSegment nextBlock = returnEnd.NextSegment;
if (_commitHead == returnEnd)
{
_commitHead = nextBlock;
_commitHeadIndex = 0;
}
_readHead = nextBlock;
_readHeadIndex = 0;
returnEnd = nextBlock;
}
else
{
_readHead = consumedSegment;
_readHeadIndex = consumed.GetInteger();
}
}
// We reset the awaitable to not completed if we've examined everything the producer produced so far
// but only if writer is not completed yet
if (examinedEverything && !_writerCompletion.IsCompleted)
{
// Prevent deadlock where reader awaits new data and writer await backpressure
if (!_writerAwaitable.IsCompleted)
{
ThrowHelper.ThrowInvalidOperationException_BackpressureDeadlock();
}
_readerAwaitable.Reset();
}
while (returnStart != null && returnStart != returnEnd)
{
returnStart.ResetMemory();
ReturnSegmentUnsynchronized(returnStart);
returnStart = returnStart.NextSegment;
}
_readingState.End();
}
TrySchedule(_writerScheduler, continuation);
}
