view sat/plugins/plugin_xep_0334.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 dcebc585c29f
line wrap: on
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#!/usr/bin/env python3


# SAT plugin for Delayed Delivery (XEP-0334)
# Copyright (C) 2009-2020 Jérôme Poisson (goffi@goffi.org)
# Copyright (C) 2013-2016 Adrien Cossa (souliane@mailoo.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/>.

from sat.core.i18n import _, D_
from sat.core.log import getLogger

log = getLogger(__name__)
from sat.core.constants import Const as C

from sat.tools.common import data_format

from wokkel import disco, iwokkel

from twisted.words.protocols.jabber import xmlstream
from zope.interface import implementer
from textwrap import dedent


PLUGIN_INFO = {
    C.PI_NAME: "Message Processing Hints",
    C.PI_IMPORT_NAME: "XEP-0334",
    C.PI_TYPE: "XEP",
    C.PI_PROTOCOLS: ["XEP-0334"],
    C.PI_MAIN: "XEP_0334",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: D_("""Implementation of Message Processing Hints"""),
    C.PI_USAGE: dedent(
        D_(
            """\
             Frontends can use HINT_* constants in mess_data['extra'] in a serialized 'hints' dict.
             Internal plugins can use directly addHint([HINT_* constant]).
             Will set mess_data['extra']['history'] to 'skipped' when no store is requested and message is not saved in history."""
        )
    ),
}

NS_HINTS = "urn:xmpp:hints"


class XEP_0334(object):
    HINT_NO_PERMANENT_STORE = "no-permanent-store"
    HINT_NO_STORE = "no-store"
    HINT_NO_COPY = "no-copy"
    HINT_STORE = "store"
    HINTS = (HINT_NO_PERMANENT_STORE, HINT_NO_STORE, HINT_NO_COPY, HINT_STORE)

    def __init__(self, host):
        log.info(_("Message Processing Hints plugin initialization"))
        self.host = host
        host.trigger.add("sendMessage", self.sendMessageTrigger)
        host.trigger.add("MessageReceived", self.messageReceivedTrigger, priority=-1000)

    def getHandler(self, client):
        return XEP_0334_handler()

    def addHint(self, mess_data, hint):
        if hint == self.HINT_NO_COPY and not mess_data["to"].resource:
            log.error(
                "{hint} can only be used with full jids! Ignoring it.".format(hint=hint)
            )
            return
        hints = mess_data.setdefault("hints", set())
        if hint in self.HINTS:
            hints.add(hint)
        else:
            log.error("Unknown hint: {}".format(hint))

    def addHintElements(self, message_elt, hints):
        """Add hints elements to message stanza

        @param message_elt(domish.Element): stanza where hints must be added
        @param hints(iterable(unicode)): hints to add
        """
        for hint in hints:
            message_elt.addElement((NS_HINTS, hint))

    def _sendPostXmlTreatment(self, mess_data):
        if "hints" in mess_data:
            self.addHintElements(mess_data["xml"], mess_data["hints"])
        return mess_data

    def sendMessageTrigger(
        self, client, mess_data, pre_xml_treatments, post_xml_treatments
    ):
        """Add the hints element to the message to be sent"""
        if "hints" in mess_data["extra"]:
            for hint in data_format.dict2iter("hints", mess_data["extra"], pop=True):
                self.addHint(hint)

        post_xml_treatments.addCallback(self._sendPostXmlTreatment)
        return True

    def _receivedSkipHistory(self, mess_data):
        mess_data["history"] = C.HISTORY_SKIP
        return mess_data

    def messageReceivedTrigger(self, client, message_elt, post_treat):
        """Check for hints in the received message"""
        for elt in message_elt.elements():
            if elt.uri == NS_HINTS and elt.name in (
                self.HINT_NO_PERMANENT_STORE,
                self.HINT_NO_STORE,
            ):
                log.debug("history will be skipped for this message, as requested")
                post_treat.addCallback(self._receivedSkipHistory)
                break
        return True


@implementer(iwokkel.IDisco)
class XEP_0334_handler(xmlstream.XMPPHandler):

    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
        return [disco.DiscoFeature(NS_HINTS)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
        return []