asynchat.py 文件源码

def initiate_send(self):
        while self.producer_fifo and self.connected:
            first = self.producer_fifo[0]
            # handle empty string/buffer or None entry
            if not first:
                del self.producer_fifo[0]
                if first is None:
                    self.handle_close()
                    return

            # handle classic producer behavior
            obs = self.ac_out_buffer_size
            try:
                with catch_warnings():
                    if py3kwarning:
                        filterwarnings("ignore", ".*buffer", DeprecationWarning)
                    data = buffer(first, 0, obs)
            except TypeError:
                data = first.more()
                if data:
                    self.producer_fifo.appendleft(data)
                else:
                    del self.producer_fifo[0]
                continue

            # send the data
            try:
                num_sent = self.send(data)
            except socket.error:
                self.handle_error()
                return

            if num_sent:
                if num_sent < len(data) or obs < len(first):
                    self.producer_fifo[0] = first[num_sent:]
                else:
                    del self.producer_fifo[0]
            # we tried to send some actual data
            return