[devtools] add has_cache for postgres (closes #5739624)
devtools stores info about existing dbs in the db handler, but in the
case of postgresql that doesn't take into account the path to the
cluster's datadir. Which means if we run two test modules (in the same
test run), we'll create a "__default_empty_db__" for the first one,
cache its existence, and then when moving on to the other module,
believe the template already exists (but since the datadir depends on
the test module's path, it does not). This patch is a bit of a kludge,
and it would be better to make the cache key include enough data to not
need this, but I'm not sure how to do that.
# -*- coding: utf-8 -*-
# copyright 2012-2014 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
from threading import Thread
from logging import getLogger
import zmq
from zmq.eventloop import ioloop
import zmq.eventloop.zmqstream
from cubicweb import set_log_methods
ctx = zmq.Context()
class ZMQComm(object):
"""
A simple ZMQ-based notification bus.
There should at most one instance of this class attached to a
Repository. A typical usage may be something like::
def callback(msg):
self.info('received message: %s', ' '.join(msg))
repo.app_instances_bus.subscribe('hello', callback)
to subsribe to the 'hello' kind of message. On the other side, to
emit a notification, call::
repo.app_instances_bus.publish(['hello', 'world'])
See http://docs.cubicweb.org for more details.
"""
def __init__(self):
self.ioloop = ioloop.IOLoop()
self._topics = {}
self._subscribers = []
self.publisher = None
def add_publisher(self, address):
assert self.publisher is None, "more than one publisher is not supported"
self.publisher = Publisher(self.ioloop, address)
def add_subscription(self, topic, callback):
for subscriber in self._subscribers:
subscriber.subscribe(topic, callback)
self._topics[topic] = callback
def add_subscriber(self, address):
subscriber = Subscriber(self.ioloop, address)
for topic, callback in self._topics.iteritems():
subscriber.subscribe(topic, callback)
self._subscribers.append(subscriber)
def publish(self, msg):
if self.publisher is None:
return
self.publisher.send(msg)
def start(self):
Thread(target=self.ioloop.start).start()
def stop(self):
self.ioloop.add_callback(self.ioloop.stop)
def __del__(self):
self.ioloop.close()
class Publisher(object):
def __init__(self, ioloop, address):
self.address = address
self._topics = {}
self._subscribers = []
self.ioloop = ioloop
def callback():
s = ctx.socket(zmq.PUB)
self.stream = zmq.eventloop.zmqstream.ZMQStream(s, io_loop=ioloop)
self.stream.bind(self.address)
self.debug('start publisher on %s', self.address)
ioloop.add_callback(callback)
def send(self, msg):
self.ioloop.add_callback(lambda:self.stream.send_multipart(msg))
class Subscriber(object):
def __init__(self, ioloop, address):
self.address = address
self.dispatch_table = {}
self.ioloop = ioloop
def callback():
s = ctx.socket(zmq.SUB)
self.stream = zmq.eventloop.zmqstream.ZMQStream(s, io_loop=ioloop)
self.stream.on_recv(self.dispatch)
self.stream.connect(self.address)
self.debug('start subscriber on %s', self.address)
ioloop.add_callback(callback)
def dispatch(self, msg):
try:
f = self.dispatch_table[msg[0]]
except KeyError:
return
f(msg)
def subscribe(self, topic, callback):
self.dispatch_table[topic] = callback
self.ioloop.add_callback(lambda: self.stream.setsockopt(zmq.SUBSCRIBE, topic))
set_log_methods(Publisher, getLogger('cubicweb.zmq.pub'))
set_log_methods(Subscriber, getLogger('cubicweb.zmq.sub'))