contrib/zeromq/TZmqServer.py

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# Licensed to the Apache Software Foundation (ASF) under one
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# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
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import logging
import zmq
import thrift.server.TServer
import thrift.transport.TTransport

class TZmqServer(thrift.server.TServer.TServer):
  def __init__(self, processor, ctx, endpoint, sock_type):
    thrift.server.TServer.TServer.__init__(self, processor, None)
    self.zmq_type = sock_type
    self.socket = ctx.socket(sock_type)
    self.socket.bind(endpoint)

  def serveOne(self):
    msg = self.socket.recv()
    itrans = thrift.transport.TTransport.TMemoryBuffer(msg)
    otrans = thrift.transport.TTransport.TMemoryBuffer()
    iprot = self.inputProtocolFactory.getProtocol(itrans)
    oprot = self.outputProtocolFactory.getProtocol(otrans)

    try:
      self.processor.process(iprot, oprot)
    except Exception:
      logging.exception("Exception while processing request")
      # Fall through and send back a response, even if empty or incomplete.

    if self.zmq_type == zmq.REP:
      msg = otrans.getvalue()
      self.socket.send(msg)

  def serve(self):
    while True:
      self.serveOne()


class TZmqMultiServer(object):
  def __init__(self):
    self.servers = []

  def serveOne(self, timeout = -1):
    self._serveActive(self._setupPoll(), timeout)

  def serveForever(self):
    poll_info = self._setupPoll()
    while True:
      self._serveActive(poll_info, -1)

  def _setupPoll(self):
    server_map = {}
    poller = zmq.Poller()
    for server in self.servers:
      server_map[server.socket] = server
      poller.register(server.socket, zmq.POLLIN)
    return (server_map, poller)

  def _serveActive(self, poll_info, timeout):
    (server_map, poller) = poll_info
    ready = dict(poller.poll())
    for sock, state in ready.items():
      assert (state & zmq.POLLIN) != 0
      server_map[sock].serveOne()