view sat/tools/async_trigger.py @ 3153:2c7b42f53e9a

core (xmpp): avoid starting several clients at the same time: a check is done to avoid running startConnection several times at once, which would lead to the creation of several SatXMPPEntity instances at the same time, resulting in many issues. If startConnection is called while a previous one is not finished yet, a CancelError is now raised.
author Goffi <goffi@goffi.org>
date Mon, 03 Feb 2020 13:46:24 +0100
parents 559a625a236b
children c069882f64cb
line wrap: on
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#!/usr/bin/env python3


# SAT: a jabber client
# Copyright (C) 2009-2020 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""Misc usefull classes"""

from sat.tools import trigger as sync_trigger
from twisted.internet import defer

class TriggerManager(sync_trigger.TriggerManager):
    """This is a TriggerManager with an new asyncPoint method"""

    @defer.inlineCallbacks
    def asyncPoint(self, point_name, *args, **kwargs):
        """This put a trigger point with potentially async Deferred

        All the triggers for that point will be run
        @param point_name: name of the trigger point
        @param *args: args to transmit to trigger
        @param *kwargs: kwargs to transmit to trigger
            if "triggers_no_cancel" is present, it will be popped out
                when set to True, this argument don't let triggers stop
                the workflow
        @return D(bool): True if the action must be continued, False else
        """
        if point_name not in self.__triggers:
            defer.returnValue(True)

        can_cancel = not kwargs.pop('triggers_no_cancel', False)

        for priority, trigger in self.__triggers[point_name]:
            try:
                cont = yield trigger(*args, **kwargs)
                if can_cancel and not cont:
                    defer.returnValue(False)
            except sync_trigger.SkipOtherTriggers:
                break
        defer.returnValue(True)