os-ken/ryu/controller/handler.py
YAMAMOTO Takashi 77e82d3111 controller.handler: simplify code
and use consistent variable names.  no functional changes.

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
2014-04-10 07:09:56 +09:00

123 lines
3.9 KiB
Python

# Copyright (C) 2011-2014 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
#
# Licensed 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
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
import logging
import sys
LOG = logging.getLogger('ryu.controller.handler')
# just represent OF datapath state. datapath specific so should be moved.
HANDSHAKE_DISPATCHER = "handshake"
CONFIG_DISPATCHER = "config"
MAIN_DISPATCHER = "main"
DEAD_DISPATCHER = "dead"
class _Caller(object):
"""Describe how to handle an event class.
"""
def __init__(self, dispatchers, ev_source):
"""Initialize _Caller.
:param dispatchers: A list of states or a state, in which this
is in effect.
None and [] mean all states.
:param ev_source: The module which generates the event.
ev_cls.__module__ for set_ev_cls.
None for set_ev_handler.
"""
self.dispatchers = dispatchers
self.ev_source = ev_source
# should be named something like 'observe_event'
def set_ev_cls(ev_cls, dispatchers=None):
def _set_ev_cls_dec(handler):
if 'callers' not in dir(handler):
handler.callers = {}
for e in _listify(ev_cls):
handler.callers[e] = _Caller(_listify(dispatchers), e.__module__)
return handler
return _set_ev_cls_dec
def set_ev_handler(ev_cls, dispatchers=None):
def _set_ev_cls_dec(handler):
if 'callers' not in dir(handler):
handler.callers = {}
for e in _listify(ev_cls):
handler.callers[e] = _Caller(_listify(dispatchers), None)
return handler
return _set_ev_cls_dec
def _has_caller(meth):
return hasattr(meth, 'callers')
def _listify(may_list):
if may_list is None:
may_list = []
if not isinstance(may_list, list):
may_list = [may_list]
return may_list
def register_instance(i):
for _k, m in inspect.getmembers(i, inspect.ismethod):
# LOG.debug('instance %s k %s m %s', i, _k, m)
if _has_caller(m):
for ev_cls, c in m.callers.iteritems():
i.register_handler(ev_cls, m)
def get_dependent_services(cls):
services = []
for _k, m in inspect.getmembers(cls, inspect.ismethod):
if _has_caller(m):
for ev_cls, c in m.callers.iteritems():
service = getattr(sys.modules[ev_cls.__module__],
'_SERVICE_NAME', None)
if service:
# avoid cls that registers the own events (like
# ofp_handler)
if cls.__module__ != service:
services.append(service)
m = sys.modules[cls.__module__]
services.extend(getattr(m, '_REQUIRED_APP', []))
services = list(set(services))
return services
def register_service(service):
"""
Register the ryu application specified by 'service' as
a provider of events defined in the calling module.
If an application being loaded consumes events (in the sense of
set_ev_cls) provided by the 'service' application, the latter
application will be automatically loaded.
This mechanism is used to e.g. automatically start ofp_handler if
there are applications consuming OFP events.
"""
frm = inspect.stack()[1]
m = inspect.getmodule(frm[0])
m._SERVICE_NAME = service