/usr/lib/python3/dist-packages/provisioningserver/utils/events.py is in python3-maas-provisioningserver 2.4.0~beta2-6865-gec43e47e6-0ubuntu1.
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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 | # Copyright 2015-2016 Canonical Ltd. This software is licensed under the
# GNU Affero General Public License version 3 (see the file LICENSE).
"""Event-related utilities."""
__all__ = [
"Event",
"EventGroup",
]
class Event:
"""Simple event that when fired calls all of the registered handlers on
this event."""
def __init__(self):
self.handlers = set()
def registerHandler(self, handler):
"""Register handler to event."""
self.handlers.add(handler)
def unregisterHandler(self, handler):
"""Unregister handler from event."""
self.handlers.discard(handler)
def fire(self, *args, **kwargs):
"""Fire the event."""
# Shallow-copy the set to avoid "size changed during iteration"
# errors. This is a fast operation: faster than switching to an
# immutable set or using thread-safe locks (and won't deadlock).
for handler in self.handlers.copy():
handler(*args, **kwargs)
class EventGroup:
"""Group of events.
Provides a quick way of creating a group of events for an object. Access
the events as properties on this object.
Example:
events = EventGroup("connected", "disconnected")
events.connected.fire()
events.disconnected.fire()
"""
def __init__(self, *events):
for event in events:
setattr(self, event, Event())
|