public static void Pipe(this IBufferOperation transformation, ReadOnlyBytes source, IOutput destination)
{
int afterMergeSlice = 0;
// Assign 'remainder' to something formally stack-referring.
// The default classification is "returnable, not referring to stack", we want the opposite in this case.
ReadOnlySpan <byte> remainder = stackalloc byte[0];
Span <byte> stackSpan = stackalloc byte[stackLength];
var poisition = Position.First;
while (source.TryGet(ref poisition, out var sourceBuffer, true))
{
Span <byte> outputSpan = destination.Buffer;
ReadOnlySpan <byte> sourceSpan = sourceBuffer.Span;
if (!remainder.IsEmpty)
{
int leftOverBytes = remainder.Length;
remainder.CopyTo(stackSpan);
int amountToCopy = Math.Min(sourceSpan.Length, stackSpan.Length - leftOverBytes);
sourceSpan.Slice(0, amountToCopy).CopyTo(stackSpan.Slice(leftOverBytes));
int amountOfData = leftOverBytes + amountToCopy;
Span <byte> spanToTransform = stackSpan.Slice(0, amountOfData);
TryTransformWithRemainder:
OperationStatus status = transformation.Execute(spanToTransform, outputSpan, out int bytesConsumed, out int bytesWritten);
if (status != OperationStatus.Done)
{
destination.Advance(bytesWritten);
spanToTransform = spanToTransform.Slice(bytesConsumed);
if (status == OperationStatus.DestinationTooSmall)
{
destination.Enlarge(); // output buffer is too small
outputSpan = destination.Buffer;
if (outputSpan.Length - bytesWritten < 3)
{
return; // no more output space, user decides what to do.
}
goto TryTransformWithRemainder;
}
else
{
if (status == OperationStatus.InvalidData)
{
continue; // source buffer contains invalid bytes, user decides what to do for fallback
}
// at this point, status = TransformationStatus.NeedMoreSourceData
// left over bytes in stack span
remainder = spanToTransform;
}
continue;
}
else // success
{
afterMergeSlice = bytesConsumed - remainder.Length;
remainder = Span <byte> .Empty;
destination.Advance(bytesWritten);
outputSpan = destination.Buffer;
}
}
TryTransform:
OperationStatus result = transformation.Execute(sourceSpan.Slice(afterMergeSlice), outputSpan, out int consumed, out int written);
afterMergeSlice = 0;
destination.Advance(written);
sourceSpan = sourceSpan.Slice(consumed);
if (result == OperationStatus.Done)
{
continue;
}
// Not successful
if (result == OperationStatus.DestinationTooSmall)
{
destination.Enlarge(); // output buffer is too small
outputSpan = destination.Buffer;
if (outputSpan.Length - written < 3)
{
return; // no more output space, user decides what to do.
}
goto TryTransform;
}
else
{
if (result == OperationStatus.InvalidData)
{
continue; // source buffer contains invalid bytes, user decides what to do for fallback
}
// at this point, result = TransformationStatus.NeedMoreSourceData
// left over bytes in source span
remainder = sourceSpan;
}
}
return;
}
public BytesReader(ReadOnlyBytes bytes) : this(bytes, SymbolTable.InvariantUtf8)
{
}
public BytesReader(ReadOnlyBytes bytes) : this(bytes, TextEncoder.Utf8)
{
}
public BytesReader(ReadOnlyBytes bytes) : this(bytes, EncodingData.InvariantUtf8)
{
}