/usr/lib/python2.7/dist-packages/ovsdbapp/event.py is in python-ovsdbapp 0.9.1-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | # 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 abc
import atexit
import logging
import threading
import six
from six.moves import queue as Queue
LOG = logging.getLogger(__name__)
STOP_EVENT = ("STOP", None, None, None)
@six.add_metaclass(abc.ABCMeta)
class RowEvent(object):
ROW_CREATE = "create"
ROW_UPDATE = "update"
ROW_DELETE = "delete"
ONETIME = False
event_name = 'RowEvent'
def __init__(self, events, table, conditions, old_conditions=None):
self.table = table
self.events = events
self.conditions = conditions
self.old_conditions = old_conditions
@property
def key(self):
return (self.__class__, self.table, self.events, self.conditions)
def __hash__(self):
return hash(self.key)
def __eq__(self, other):
try:
return self.key == other.key
except AttributeError:
return False
def __ne__(self, other):
return not self == other
@abc.abstractmethod
def matches(self, event, row, old=None):
"""Test that `event` on `row` matches watched events
:param event: event type
:type event: ROW_CREATE, ROW_UPDATE, or ROW_DELETE
:param row:
:param old:
:returns: boolean, True if match else False
"""
@abc.abstractmethod
def run(self, event, row, old):
"""Method to run when the event matches"""
class RowEventHandler(object):
def __init__(self):
self.__watched_events = set()
self.__lock = threading.Lock()
self.notifications = Queue.Queue()
self.notify_thread = threading.Thread(target=self.notify_loop)
self.notify_thread.daemon = True
atexit.register(self.shutdown)
self.start()
def start(self):
self.notify_thread.start()
def matching_events(self, event, row, updates):
with self.__lock:
return tuple(t for t in self.__watched_events
if t.matches(event, row, updates))
def watch_event(self, event):
with self.__lock:
self.__watched_events.add(event)
def watch_events(self, events):
with self.__lock:
for event in events:
self.__watched_events.add(event)
def unwatch_event(self, event):
with self.__lock:
self.__watched_events.discard(event)
def unwatch_events(self, events):
with self.__lock:
for event in events:
self.__watched_events.discard(event)
def shutdown(self):
self.notifications.put(STOP_EVENT)
def notify_loop(self):
while True:
try:
match, event, row, updates = self.notifications.get()
if (match, event, row, updates) == STOP_EVENT:
self.notifications.task_done()
break
match.run(event, row, updates)
if match.ONETIME:
self.unwatch_event(match)
self.notifications.task_done()
except Exception:
# If any unexpected exception happens we don't want the
# notify_loop to exit.
LOG.exception('Unexpected exception in notify_loop')
def notify(self, event, row, updates=None):
matching = self.matching_events(
event, row, updates)
for match in matching:
self.notifications.put((match, event, row, updates))
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