view libervia/server/utils.py @ 1504:409d10211b20

server, browser: dynamic pages refactoring: dynamic pages has been reworked, to change the initial basic implementation. Pages are now dynamic by default, and a websocket is established by the first connected page of a session. The socket is used to transmit bridge signals, and then the signal is broadcasted to other tabs using broadcast channel. If the connecting tab is closed, an other one is chosen. Some tests are made to retry connecting in case of problem, and sometimes reload the pages (e.g. if profile is connected). Signals (or other data) are cached during reconnection phase, to avoid lost of data. All previous partial rendering mechanism have been removed, chat page is temporarily not working anymore, but will be eventually redone (one of the goal of this work is to have proper chat).
author Goffi <goffi@goffi.org>
date Wed, 01 Mar 2023 18:02:44 +0100
parents 822bd0139769
children 106bae41f5c8
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#!/usr/bin/env python3


# Libervia: a Salut à Toi frontend
# Copyright (C) 2011-2021 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/>.
from sat.core.i18n import _
from twisted.internet import reactor
from twisted.internet import defer
from sat.core import exceptions
from sat.core.log import getLogger
import urllib.request, urllib.parse, urllib.error

log = getLogger(__name__)


def quote(value, safe="@"):
    """shortcut to quote an unicode value for URL"""
    return urllib.parse.quote(value, safe=safe)


class ProgressHandler(object):
    """class to help the management of progressions"""

    handlers = {}

    def __init__(self, host, progress_id, profile):
        self.host = host
        self.progress_id = progress_id
        self.profile = profile

    @classmethod
    def _signal(cls, name, progress_id, data, profile):
        handlers = cls.handlers
        if profile in handlers and progress_id in handlers[profile]:
            handler_data = handlers[profile][progress_id]
            timeout = handler_data["timeout"]
            if timeout.active():
                timeout.cancel()
            cb = handler_data[name]
            if cb is not None:
                cb(data)
            if name == "started":
                pass
            elif name == "finished":
                handler_data["deferred"].callback(data)
                handler_data["instance"].unregister_handler()
            elif name == "error":
                handler_data["deferred"].errback(Exception(data))
                handler_data["instance"].unregister_handler()
            else:
                log.error("unexpected signal: {name}".format(name=name))

    def _timeout(self):
        log.warning(
            _(
                "No progress received, cancelling handler: {progress_id} [{profile}]"
            ).format(progress_id=self.progress_id, profile=self.profile)
        )

    def unregister_handler(self):
        """remove a previously registered handler"""
        try:
            del self.handlers[self.profile][self.progress_id]
        except KeyError:
            log.warning(
                _("Trying to remove unknown handler: {progress_id} [{profile}]").format(
                    progress_id=self.progress_id, profile=self.profile
                )
            )
        else:
            if not self.handlers[self.profile]:
                self.handlers[self.profile]

    def register(self, started_cb=None, finished_cb=None, error_cb=None, timeout=30):
        """register the signals to handle progression

        @param started_cb(callable, None): method to call when progressStarted signal is received
        @param finished_cb(callable, None): method to call when progressFinished signal is received
        @param error_cb(callable, None): method to call when progressError signal is received
        @param timeout(int): progress time out
            if nothing happen in this progression during this delay,
            an exception is raised
        @return (D(dict[unicode,unicode])): a deferred called when progression is finished
        """
        handler_data = self.handlers.setdefault(self.profile, {}).setdefault(
            self.progress_id, {}
        )
        if handler_data:
            raise exceptions.ConflictError(
                "There is already one handler for this progression"
            )
        handler_data["instance"] = self
        deferred = handler_data["deferred"] = defer.Deferred()
        handler_data["started"] = started_cb
        handler_data["finished"] = finished_cb
        handler_data["error"] = error_cb
        handler_data["timeout"] = reactor.callLater(timeout, self._timeout)
        return deferred


class SubPage(str):
    """use to mark subpages when generating a page path"""