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Diffstat (limited to 'src/leap/services/abstractbootstrapper.py')
| -rw-r--r-- | src/leap/services/abstractbootstrapper.py | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/leap/services/abstractbootstrapper.py b/src/leap/services/abstractbootstrapper.py new file mode 100644 index 00000000..bce03e6b --- /dev/null +++ b/src/leap/services/abstractbootstrapper.py @@ -0,0 +1,155 @@ +# -*- coding: utf-8 -*- +# abstractbootstrapper.py +# Copyright (C) 2013 LEAP +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU 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 General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +""" +Abstract bootstrapper implementation +""" +import logging + +import requests + +from PySide import QtCore +from twisted.internet import threads +from leap.common.check import leap_assert, leap_assert_type + +logger = logging.getLogger(__name__) + + +class AbstractBootstrapper(QtCore.QObject): + """ + Abstract Bootstrapper that implements the needed deferred callbacks + """ + + PASSED_KEY = "passed" + ERROR_KEY = "error" + + def __init__(self, bypass_checks=False): + """ + Constructor for the abstract bootstrapper + + :param bypass_checks: Set to true if the app should bypass + first round of checks for CA + certificates at bootstrap + :type bypass_checks: bool + """ + QtCore.QObject.__init__(self) + + leap_assert(self._gui_errback.im_func == \ + AbstractBootstrapper._gui_errback.im_func, + "Cannot redefine _gui_errback") + leap_assert(self._errback.im_func == \ + AbstractBootstrapper._errback.im_func, + "Cannot redefine _errback") + leap_assert(self._gui_notify.im_func == \ + AbstractBootstrapper._gui_notify.im_func, + "Cannot redefine _gui_notify") + + # **************************************************** # + # Dependency injection helpers, override this for more + # granular testing + self._fetcher = requests + # **************************************************** # + + self._session = self._fetcher.session() + self._bypass_checks = bypass_checks + self._signal_to_emit = None + self._err_msg = None + + def _gui_errback(self, failure): + """ + Errback used to notify the GUI of a problem, it should be used + as the last errback of the whole chain. + + Traps all exceptions if a signal is defined, otherwise it just + lets it continue. + + NOTE: This method is final, it should not be redefined. + + :param failure: failure object that Twisted generates + :type failure: twisted.python.failure.Failure + """ + if self._signal_to_emit: + err_msg = self._err_msg \ + if self._err_msg is not None \ + else str(failure.value) + self._signal_to_emit.emit({ + self.PASSED_KEY: False, + self.ERROR_KEY: err_msg + }) + failure.trap(Exception) + + def _errback(self, failure, signal=None): + """ + Regular errback used for the middle of the chain. If it's + executed, the first one will set the signal to emit as + failure. + + NOTE: This method is final, it should not be redefined. + + :param failure: failure object that Twisted generates + :type failure: twisted.python.failure.Failure + :param signal: Signal to emit if it fails here first + :type signal: QtCore.SignalInstance + + :returns: failure object that Twisted generates + :rtype: twisted.python.failure.Failure + """ + if self._signal_to_emit is None: + self._signal_to_emit = signal + return failure + + def _gui_notify(self, _, signal=None): + """ + Callback used to notify the GUI of a success. Will emit signal + if specified + + NOTE: This method is final, it should not be redefined. + + :param _: IGNORED. Returned from the previous callback + :type _: IGNORED + :param signal: Signal to emit if it fails here first + :type signal: QtCore.SignalInstance + """ + if signal: + logger.debug("Emitting %s" % (signal,)) + signal.emit({self.PASSED_KEY: True, self.ERROR_KEY: ""}) + + def addCallbackChain(self, callbacks): + """ + Creates a callback/errback chain on another thread using + deferToThread and adds the _gui_errback to the end to notify + the GUI on an error. + + :param callbacks: List of tuples of callbacks and the signal + associated to that callback + :type callbacks: list(tuple(func, func)) + """ + leap_assert_type(callbacks, list) + + self._signal_to_emit = None + self._err_msg = None + + d = None + for cb, sig in callbacks: + if d is None: + d = threads.deferToThread(cb) + else: + d.addCallback(cb) + d.addErrback(self._errback, signal=sig) + d.addCallback(self._gui_notify, signal=sig) + d.addErrback(self._gui_errback) + |