This commit consists of the following:
1) The kafka messaging proxy in Twisted python for adapters
2) Initial implementation and containerization of ponsim OLT adapter
and ponsim ONU adapter
3) Initial submission of request and response facade in both Twisted
python and Go Language
4) Initial implementation of device management and logical device management
in the Core
5) Update to the log module to allow dynamic setting of log level per
package using the gRPC API
6) Bug fixes and minor changes
Change-Id: Ia8f033da84cfd08275335bae9542802415e7bb0f
diff --git a/adapters/common/event_bus.py b/adapters/common/event_bus.py
new file mode 100644
index 0000000..e717c16
--- /dev/null
+++ b/adapters/common/event_bus.py
@@ -0,0 +1,194 @@
+#
+# Copyright 2017 the original author or authors.
+#
+# 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.
+#
+
+"""
+A simple internal pub/sub event bus with topics and filter-based registration.
+"""
+import re
+
+import structlog
+
+
+log = structlog.get_logger()
+
+
+class _Subscription(object):
+
+ __slots__ = ('bus', 'predicate', 'callback', 'topic')
+ def __init__(self, bus, predicate, callback, topic=None):
+ self.bus = bus
+ self.predicate = predicate
+ self.callback = callback
+ self.topic = topic
+
+
+class EventBus(object):
+
+ def __init__(self):
+ self.subscriptions = {} # topic -> list of _Subscription objects
+ # topic None holds regexp based topic subs.
+ self.subs_topic_map = {} # to aid fast lookup when unsubscribing
+
+ def list_subscribers(self, topic=None):
+ if topic is None:
+ return sum(self.subscriptions.itervalues(), [])
+ else:
+ if topic in self.subscriptions:
+ return self.subscriptions[topic]
+ else:
+ return []
+
+ @staticmethod
+ def _get_topic_key(topic):
+ if isinstance(topic, str):
+ return topic
+ elif hasattr(topic, 'match'):
+ return None
+ else:
+ raise AttributeError('topic not a string nor a compiled regex')
+
+ def subscribe(self, topic, callback, predicate=None):
+ """
+ Subscribe to given topic with predicate and register the callback
+ :param topic: String topic (explicit) or regexp based topic filter.
+ :param callback: Callback method with signature def func(topic, msg)
+ :param predicate: Optional method/function signature def predicate(msg)
+ :return: Subscription object which can be used to unsubscribe
+ """
+ subscription = _Subscription(self, predicate, callback, topic)
+ topic_key = self._get_topic_key(topic)
+ self.subscriptions.setdefault(topic_key, []).append(subscription)
+ self.subs_topic_map[subscription] = topic_key
+ return subscription
+
+ def unsubscribe(self, subscription):
+ """
+ Remove given subscription
+ :param subscription: subscription object as was returned by subscribe
+ :return: None
+ """
+ topic_key = self.subs_topic_map[subscription]
+ self.subscriptions[topic_key].remove(subscription)
+
+ def publish(self, topic, msg):
+ """
+ Publish given message to all subscribers registered with topic taking
+ the predicate functions into account.
+ :param topic: String topic
+ :param msg: Arbitrary python data as message
+ :return: None
+ """
+ from copy import copy
+
+ def passes(msg, predicate):
+ try:
+ return predicate(msg)
+ except Exception, e:
+ return False # failed predicate function treated as no match
+
+ # lookup subscribers with explicit topic subscriptions
+ subscribers = self.subscriptions.get(topic, [])
+
+ # add matching regexp topic subscribers
+ subscribers.extend(s for s in self.subscriptions.get(None, [])
+ if s.topic.match(topic))
+
+ # iterate over a shallow-copy of subscribers
+ for candidate in copy(subscribers):
+ predicate = candidate.predicate
+ if predicate is None or passes(msg, predicate):
+ try:
+ candidate.callback(topic, msg)
+ except Exception, e:
+ log.exception('callback-failed', e=repr(e), topic=topic)
+
+
+
+default_bus = EventBus()
+
+
+class EventBusClient(object):
+ """
+ Primary interface to the EventBus. Usage:
+
+ Publish:
+ >>> events = EventBusClient()
+ >>> msg = dict(a=1, b='foo')
+ >>> events.publish('a.topic', msg)
+
+ Subscribe to get all messages on specific topic:
+ >>> def got_event(topic, msg):
+ >>> print topic, ':', msg
+ >>> events = EventBusClient()
+ >>> events.subscribe('a.topic', got_event)
+
+ Subscribe to get messages matching predicate on specific topic:
+ >>> def got_event(topic, msg):
+ >>> print topic, ':', msg
+ >>> events = EventBusClient()
+ >>> events.subscribe('a.topic', got_event, lambda msg: msg.len() < 100)
+
+ Use a DeferredQueue to buffer incoming messages
+ >>> queue = DeferredQueue()
+ >>> events = EventBusClient()
+ >>> events.subscribe('a.topic', lambda _, msg: queue.put(msg))
+
+ """
+ def __init__(self, bus=None):
+ """
+ Obtain a client interface for the pub/sub event bus.
+ :param bus: An optional specific event bus. Inteded for mainly test
+ use. If not provided, the process default bus will be used, which is
+ the preferred use (a process shall not need more than one bus).
+ """
+ self.bus = bus or default_bus
+
+ def publish(self, topic, msg):
+ """
+ Publish given msg to given topic.
+ :param topic: String topic
+ :param msg: Arbitrary python data as message
+ :return: None
+ """
+ self.bus.publish(topic, msg)
+
+ def subscribe(self, topic, callback, predicate=None):
+ """
+ Subscribe to given topic with predicate and register the callback
+ :param topic: String topic (explicit) or regexp based topic filter.
+ :param callback: Callback method with signature def func(topic, msg)
+ :param predicate: Optional method/function with signature
+ def predicate(msg)
+ :return: Subscription object which can be used to unsubscribe
+ """
+ return self.bus.subscribe(topic, callback, predicate)
+
+ def unsubscribe(self, subscription):
+ """
+ Remove given subscription
+ :param subscription: subscription object as was returned by subscribe
+ :return: None
+ """
+ return self.bus.unsubscribe(subscription)
+
+ def list_subscribers(self, topic=None):
+ """
+ Return list of subscribers. If topci is provided, it is filtered for
+ those subscribing to the topic.
+ :param topic: Optional topic
+ :return: List of subscriptions
+ """
+ return self.bus.list_subscribers(topic)