FUJITA Tomonori aa5051a162 initial commit
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
2011-12-09 15:56:05 +09:00

109 lines
3.3 KiB
Python

# Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2011 Isaku Yamahata <yamahata at valinux co jp>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import copy
import logging
from gevent import queue
LOG = logging.getLogger('ryu.controller.dispatcher')
class EventQueue(object):
def __init__(self, dispatcher):
self.dispatcher = dispatcher
self.is_dispatching = False
self.ev_q = queue.Queue()
def set_dispatcher(self, dispatcher):
self.dispatcher = dispatcher
def queue_raw(self, ev):
self.ev_q.put(ev)
class _EventQueueGuard(object):
def __init__(self, ev_q):
self.ev_q = ev_q
def __enter__(self):
self.ev_q.is_dispatching = True
def __exit__(self, type, value, traceback):
self.ev_q.is_dispatching = False
return False
def queue(self, ev):
if self.is_dispatching:
self.queue_raw(ev)
return
with self._EventQueueGuard(self):
assert self.ev_q.empty()
self.dispatcher(ev)
while not self.ev_q.empty():
ev = self.ev_q.get()
self.dispatcher(ev)
class EventDispatcher(object):
def __init__(self, name):
self.name = name
self.events = {}
def register_handler(self, ev_cls, handler):
assert callable(handler)
self.events.setdefault(ev_cls, [])
self.events[ev_cls].append(handler)
def register_handlers(self, handlers):
for ev_cls, h in handlers:
self.register_handler(ev_cls, h)
def unregister_handler(self, ev_cls, handler):
del self.events[ev_cls][handler]
def register_static(self, ev_cls):
'''helper decorator to statically register handler for event class'''
def register(handler):
'''helper decorator to register handler statically '''
if isinstance(handler, staticmethod):
# class staticmethod is not callable.
handler = handler.__func__
self.register_handler(ev_cls, handler)
return handler
return register
def __call__(self, ev):
self.dispatch(ev)
def dispatch(self, ev):
#LOG.debug('dispatch %s', ev)
if ev.__class__ not in self.events:
LOG.info('unhandled event %s', ev)
return
# Is this necessary?
#
# copy handler list because the list is not stable.
# event handler may block/switch thread execution
# and un/register other handlers.
#
handlers = copy.copy(self.events[ev.__class__])
for h in handlers:
ret = h(ev)
if ret is False:
break