WrappedStream.Write C# (CSharp) Method

    public override void Write(byte[] buffer, int offset, int count)
    {
        if (CanWrite)
        {
            try
            {
                _baseStream.Write(buffer, offset, count);
            }
            catch (ObjectDisposedException ex)
            {
                throw new NotSupportedException("This stream does not support writing", ex);
            }
        }
        else throw new NotSupportedException("This stream does not support writing");
    }

        private void DoOperation(ModifyStream modifyStream, ModifyBuffer modifyBuffer, int count)
        {
            int startOffset = (int)(_position % _blockSize);

            if (startOffset == 0 && (count % _blockSize == 0 || _position + count == Length))
            {
                WrappedStream.Position = _position;
                modifyStream(WrappedStream, 0, count);
                _position += count;
                return;
            }

            long unalignedEnd = _position + count;
            long alignedPos   = MathUtilities.RoundDown(_position, _blockSize);

            if (startOffset != 0)
            {
                WrappedStream.Position = alignedPos;
                WrappedStream.Read(_alignmentBuffer, 0, _blockSize);

                modifyBuffer(_alignmentBuffer, startOffset, 0, Math.Min(count, _blockSize - startOffset));

                WrappedStream.Position = alignedPos;
                WrappedStream.Write(_alignmentBuffer, 0, _blockSize);
            }

            alignedPos = MathUtilities.RoundUp(_position, _blockSize);
            if (alignedPos >= unalignedEnd)
            {
                _position = unalignedEnd;
                return;
            }

            int passthroughLength = (int)MathUtilities.RoundDown(_position + count - alignedPos, _blockSize);

            if (passthroughLength > 0)
            {
                WrappedStream.Position = alignedPos;
                modifyStream(WrappedStream, (int)(alignedPos - _position), passthroughLength);
            }

            alignedPos += passthroughLength;
            if (alignedPos >= unalignedEnd)
            {
                _position = unalignedEnd;
                return;
            }

            WrappedStream.Position = alignedPos;
            WrappedStream.Read(_alignmentBuffer, 0, _blockSize);

            modifyBuffer(_alignmentBuffer, 0, (int)(alignedPos - _position), (int)Math.Min(count - (alignedPos - _position), unalignedEnd - alignedPos));

            WrappedStream.Position = alignedPos;
            WrappedStream.Write(_alignmentBuffer, 0, _blockSize);

            _position = unalignedEnd;
        }