protected override ISegment CreateEmptySegment()
{
#if UNMANAGED
return(PointerSegment.Create(true));
#else
return(BufferSegment.Create());
#endif
}
bool ISegmentFactory.ReadNext(Message message)
{
if (remainingWords == 0)
{
return(false);
}
ulong word = ReadUInt64();
int segments = (int)(uint)(word) + 1;
// layout is:
// [count-1][len0]
// [len1][len2]
// [len3][len4]
// ...
// [lenN][padding]
// so: we can use count/2 as a sneaky way of knowing how many extra words to expect
int origin = offsetBytes + 8 * (segments / 2);
message.ResetSegments(segments);
var buffer = this.buffer;
int totalWords = 0;
for (int i = 0; i < segments; i++)
{
if ((i % 2) == 0)
{
word >>= 32;
}
else
{
word = ReadUInt64();
}
var segment = (BufferSegment)message.ReuseExistingSegment() ?? BufferSegment.Create();
int len = (int)(uint)(word);
segment.Init(buffer, origin, len, len);
message.AddSegment(segment);
origin += (len << 3);
totalWords += len;
}
// move the base offset past the data
ConsumeWords(totalWords);
if (origin != offsetBytes)
{
throw new InvalidOperationException(string.Format("offset mismatch; craziness; {0} vs {1}", offsetBytes, origin));
}
return(true);
}
ISegment ISegmentFactory.TryAllocate(Message message, int words)
{
BufferSegment segment = null;
if (remainingWords >= words)
{
// definitely have enough
if (segmentWords > words)
{
words = segmentWords; // allocate an entire segment
if (words > remainingWords)
{
words = remainingWords; // unless that makes us too big
}
}
segment = (BufferSegment)message.ReuseExistingSegment() ?? BufferSegment.Create();
segment.Init(buffer, offsetBytes, words, 0);
ConsumeWords(words);
message.AddSegment(segment);
}
return(segment);
}
protected override ISegment CreateEmptySegment()
{
return(BufferSegment.Create());
}