From 9dd7ea0bcd9a075af96f492ca64bfc883bc031fa Mon Sep 17 00:00:00 2001 From: Sebastien Bourdeauducq Date: Sun, 22 May 2016 17:20:39 -0700 Subject: [PATCH] protocols: add broadcast (untested) --- artiq/protocols/broadcast.py | 101 +++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 artiq/protocols/broadcast.py diff --git a/artiq/protocols/broadcast.py b/artiq/protocols/broadcast.py new file mode 100644 index 000000000..b91269845 --- /dev/null +++ b/artiq/protocols/broadcast.py @@ -0,0 +1,101 @@ +import asyncio + +from artiq.protocols import pyon +from artiq.protocols.asyncio_server import AsyncioServer + + +_init_string = b"ARTIQ broadcast\n" + + +class Receiver: + def __init__(self, name, notify_cb): + self.name = name + if not isinstance(notify_cb, list): + notify_cb = [notify_cb] + self.notify_cbs = notify_cb + + async def connect(self, host, port): + self.reader, self.writer = \ + await asyncio.open_connection(host, port, limit=4*1024*1024) + try: + self.writer.write(_init_string) + self.writer.write((self.name + "\n").encode()) + self.receive_task = asyncio.ensure_future(self._receive_cr()) + except: + self.writer.close() + del self.reader + del self.writer + raise + + async def close(self): + try: + self.receive_task.cancel() + try: + await asyncio.wait_for(self.receive_task, None) + except asyncio.CancelledError: + pass + finally: + self.writer.close() + del self.reader + del self.writer + + async def _receive_cr(self): + target = None + while True: + line = await self.reader.readline() + if not line: + return + obj = pyon.decode(line.decode()) + + for notify_cb in self.notify_cbs: + notify_cb(obj) + + +class Broadcaster(AsyncioServer): + def __init__(self): + AsyncioServer.__init__(self, maxbuf=1024) + self._maxbuf = maxbuf + self._recipients = dict() + + async def _handle_connection_cr(self, reader, writer): + try: + line = await reader.readline() + if line != _init_string: + return + + line = await reader.readline() + if not line: + return + name = line.decode()[:-1] + + queue = asyncio.Queue(self._maxbuf) + if name in self._recipients: + self._recipients[name].add(queue) + else: + self._recipients[name] = {queue} + try: + while True: + line = await queue.get() + writer.write(line) + # raise exception on connection error + await writer.drain() + finally: + self._recipients[name].remove(queue) + if not self._recipients[name]: + del self._recipients[name] + except (ConnectionResetError, ConnectionAbortedError, BrokenPipeError): + # receivers disconnecting are a normal occurence + pass + finally: + writer.close() + + def broadcast(self, name, obj): + if name in self._recipients: + line = pyon.encode(obj) + "\n" + line = line.encode() + for recipient in self._recipients[name]: + try: + recipient.put_nowait(line) + except asyncio.QueueFull: + # do not log as logs may be redirected to a Broadcaster + pass