internal bool TryGetBuffer(ReadCursor end, out MemoryBlockSpan span)
{
if (IsDefault)
{
span = default(MemoryBlockSpan);
return(false);
}
var segment = _segment;
var index = _index;
if (end.Segment == segment)
{
var following = end.Index - index;
if (following > 0)
{
span = new MemoryBlockSpan(segment.Block, index, following);
_index = index + following;
return(true);
}
span = default(MemoryBlockSpan);
return(false);
}
else
{
return(TryGetBufferMultiBlock(end, out span));
}
}
private bool TryGetBufferMultiBlock(ReadCursor end, out MemoryBlockSpan span)
{
var segment = _segment;
var index = _index;
// Determine if we might attempt to copy data from segment.Next before
// calculating "following" so we don't risk skipping data that could
// be added after segment.End when we decide to copy from segment.Next.
// segment.End will always be advanced before segment.Next is set.
int following = 0;
while (true)
{
var wasLastBlock = segment.Next == null || end.Segment == segment;
if (end.Segment == segment)
{
following = end.Index - index;
}
else
{
following = segment.End - index;
}
if (following > 0)
{
break;
}
if (wasLastBlock)
{
span = default(MemoryBlockSpan);
return(false);
}
else
{
segment = segment.Next;
index = segment.Start;
}
}
span = new MemoryBlockSpan(segment.Block, index, following);
_segment = segment;
_index = index + following;
return(true);
}
private ReadableBuffer(ref ReadableBuffer buffer)
{
_channel = buffer._channel;
var begin = buffer._start;
var end = buffer._end;
MemoryBlockSegment segmentTail;
var segmentHead = MemoryBlockSegment.Clone(begin, end, out segmentTail);
begin = new ReadCursor(segmentHead);
end = new ReadCursor(segmentTail, segmentTail.End);
_start = begin;
_end = end;
_isOwner = true;
_span = buffer._span;
_length = buffer._length;
}
public Enumerator(ref ReadableBuffer buffer)
{
_buffer = buffer;
_current = default(MemoryBlockSpan);
}
