public void Push(BytesSegment bs)
{
if (bytes == null)
{
bytes = bs.GetBytes(true);
Length = bytes.Length;
return;
}
if (bytes.Length < bs.Len)
{
var newBytes = new byte[Length + bs.Len];
CopyTo(newBytes, 0, bs.Len, Length);
bytes = newBytes;
curPos = bs.Len;
}
curPos -= bs.Len;
Length += bs.Len;
Buffer.BlockCopy(bs.Bytes, bs.Offset, bytes, curPos, bs.Len);
}
public void Pop(BytesSegment bs, int count)
{
Peek(bs, count);
Sub(count);
}
public void Peek(BytesSegment bs, int count)
{
CopyTo(bs.Bytes, 0, bs.Offset, count);
}
public override async Task <int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
{
if (state == 2)
{
throw new EndOfStreamException();
}
int matchingPos = 0;
int boundaryLength = Boundary.Length;
if (state == 1)
{
state = 2;
return(0);
}
var buf = new BytesSegment(buffer, offset, count);
var bufRead = await BaseStream.ReadAsync(buffer, offset, count, cancellationToken);
var i = offset;
SEARCH:
for (; i < offset + bufRead; i++) // TODO: use KMP search algorithm
{
if (buffer[i] == Boundary[matchingPos])
{
if (++matchingPos == boundaryLength)
{
IsReadingPart = false;
state = 1;
bstream.Push(new BytesSegment(buffer, i + 1, bufRead - (i + 1)));
bufRead = i + 1 - boundaryLength;
goto ANOTHERBREAK;
}
}
else
{
if (matchingPos > 0)
{
i += -matchingPos + 1;
matchingPos = 0;
}
}
}
if (matchingPos > 0)
{
if (bufRead > matchingPos) // if got data before matching beginning
{
bstream.Push(new BytesSegment(buffer, offset + bufRead - matchingPos, matchingPos));
bufRead -= matchingPos;
}
else
{
if (buf.Len > boundaryLength)
{
var readuntil = boundaryLength;
do
{
bufRead += await BaseStream.ReadAsync(buffer, offset + bufRead, readuntil - bufRead, cancellationToken);
} while (bufRead < readuntil);
goto SEARCH;
}
else
{
// TODO
throw new NotImplementedException();
}
}
}
ANOTHERBREAK:
var ret = bufRead;
_position += ret;
return(ret);
}