--- /dev/null
+# 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):
+ """
+ A decorator for Ryu application to declare an event handler.
+
+ Decorated method will become an event handler.
+ ev_cls is an event class whose instances this RyuApp wants to receive.
+ dispatchers argument specifies one of the following negotiation phases
+ (or a list of them) for which events should be generated for this handler.
+ Note that, in case an event changes the phase, the phase before the change
+ is used to check the interest.
+
+ .. tabularcolumns:: |l|L|
+
+ =========================================== ===============================
+ Negotiation phase Description
+ =========================================== ===============================
+ ryu.controller.handler.HANDSHAKE_DISPATCHER Sending and waiting for hello
+ message
+ ryu.controller.handler.CONFIG_DISPATCHER Version negotiated and sent
+ features-request message
+ ryu.controller.handler.MAIN_DISPATCHER Switch-features message
+ received and sent set-config
+ message
+ ryu.controller.handler.DEAD_DISPATCHER Disconnect from the peer. Or
+ disconnecting due to some
+ unrecoverable errors.
+ =========================================== ===============================
+ """
+ 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.items():
+ i.register_handler(ev_cls, m)
+
+
+def _is_method(f):
+ return inspect.isfunction(f) or inspect.ismethod(f)
+
+
+def get_dependent_services(cls):
+ services = []
+ for _k, m in inspect.getmembers(cls, _is_method):
+ if _has_caller(m):
+ for ev_cls, c in m.callers.items():
+ 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.
+ """
+ frame = inspect.currentframe()
+ m_name = frame.f_back.f_globals['__name__']
+ m = sys.modules[m_name]
+ m._SERVICE_NAME = service
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