def grant()

in qpid/messaging/driver.py [0:0]
43 lines of code
15 McCabe index (conditional complexity)

  def grant(self, rcv):
    sst = self._attachments[rcv.session]
    _rcv = self._attachments.get(rcv)
    if _rcv is None or not rcv.linked or _rcv.closing or _rcv.draining:
      return

    if rcv.granted is UNLIMITED:
      if rcv.impending is UNLIMITED:
        delta = 0
      else:
        delta = UNLIMITED
    elif rcv.impending is UNLIMITED:
      delta = -1
    else:
      delta = max(rcv.granted, rcv.received) - rcv.impending

    if delta is UNLIMITED:
      if not _rcv.bytes_open:
        sst.write_cmd(MessageFlow(_rcv.destination, credit_unit.byte, UNLIMITED.value))
        _rcv.bytes_open = True
      sst.write_cmd(MessageFlow(_rcv.destination, credit_unit.message, UNLIMITED.value))
      rcv.impending = UNLIMITED
    elif delta > 0:
      if not _rcv.bytes_open:
        sst.write_cmd(MessageFlow(_rcv.destination, credit_unit.byte, UNLIMITED.value))
        _rcv.bytes_open = True
      sst.write_cmd(MessageFlow(_rcv.destination, credit_unit.message, delta))
      rcv.impending += delta
    elif delta < 0 and not rcv.draining:
      _rcv.draining = True
      def do_stop():
        rcv.impending = rcv.received
        _rcv.draining = False
        _rcv.bytes_open = False
        self.grant(rcv)
      sst.write_cmd(MessageStop(_rcv.destination), do_stop)

    if rcv.draining:
      _rcv.draining = True
      def do_flush():
        rcv.impending = rcv.received
        rcv.granted = rcv.impending
        _rcv.draining = False
        _rcv.bytes_open = False
        rcv.draining = False
      sst.write_cmd(MessageFlush(_rcv.destination), do_flush)