CqlSharp.Protocol.FrameReader.ReadSegmentAsync C# (CSharp) Method

        private async Task ReadSegmentAsync(int size)
        {
            if(_disposed)
                throw new ObjectDisposedException("FrameReader");

            if(_remainingInBuffer + _unreadFromStream < size)
                throw new IOException("Trying to read beyond frame length!");

            if(size > _buffer.Length)
            {
                //size does not fit in current buffer. Get a larger one
                var buf = MemoryPool.Instance.Take(size);

                //copy already read bytes
                Buffer.BlockCopy(_buffer, _position, buf, 0, _remainingInBuffer);

                //return old buffer, replace it with new
                MemoryPool.Instance.Return(_buffer);
                _buffer = buf;
                _position = 0;
            }

            //shift remaining buffer content to start if necessary
            if(_position + size > _buffer.Length)
            {
                Buffer.BlockCopy(_buffer, _position, _buffer, 0, _remainingInBuffer);
                _position = 0;
            }

            while(!TryGetSegmentFromBuffer(size))
            {
                //fill up the buffer with more data
                int offset = _position + _remainingInBuffer;

                //read
                int extra = await ReadAsync(_buffer, offset, _buffer.Length - offset).AutoConfigureAwait();

                if(extra == 0)
                    throw new IOException("Unexpected end of stream reached");

                _remainingInBuffer += extra;
            }
        }