Here's an idiom to send a large data buffer thru a short-write stream (e.g., non-blocking socket):

        buffer = memoryview(data).cast('b')
        while buffer:
            try:
                nsent = self._socket_send(buffer, flags)
                buffer = buffer[nsent:]

The last statement still produces bunch of object garbage. If we could do

buffer.offset(nsent)

it would be cool. Suggestions for better name are welcome.