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Viewing changes to wicd/util/orderedproviderhandler.py

  • Committer: Adam Blackburn
  • Date: 2009-07-04 23:27:35 UTC
  • mto: This revision was merged to the branch mainline in revision 20.
  • Revision ID: compwiz18@gmail.com-20090704232735-8ho5040eyhseb8ur
moved dhcp service and config service to wicd.services

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wicd/util/orderedproviderhandler.py
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    def __init__(self, servicename, must_order=False):
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        super(OrderedProviderHandler, self).__init__(servicename)
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        self.must_order = must_order
 
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        self._loading_plugins = False
 
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        # make sure to to rerun set_order if something changes
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        event.add_callback(self.changed, '%s_provider_added' % servicename)
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        event.add_callback(self.changed, '%s_provider_removed' % servicename)
 
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        event.add_callback(self.changed, 'done-loading')
 
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        # also hook on to start-loading-plugins and stop-loading-plugins
 
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        event.add_callback(self._start_loading_plugins,
 
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                           'start-loading-plugins')
 
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        event.add_callback(self._done_loading_plugins,
 
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                           'done-loading-plugins')
 
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        # grab the config path
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        config_path = os.path.join(paths.SYSTEM_CONF, '%s.conf' % servicename)
 
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        # create a ConfigObj config file
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        self.config = ConfigObj(config_path, unrepr=True)
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        logger.debug('getting value from config: %s' %
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                     self.config.get('order', default=[]))
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        self.set_order(self.config.get('order', default=[]))
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    def _start_loading_plugins(self, *args):
 
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        self._loading_plugins = True
 
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    def _done_loading_plugins(self, *args):
 
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        self._loading_plugins = False 
 
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    def changed(self, *args):
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        self.set_order(self.config.get('order', default=[]), save=False)
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    def set_order(self, order, save=True):
 
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        # don't bother while we're loading plugins
 
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        if self._loading_plugins: return
 
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        # should we save this new order?
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        if save:
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            self.config['order'] = order
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            self.config.write()
 
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        # make it easy to find providers by name
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        def find_by_name(name, listing):
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            for provider in listing:
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                if provider.name == name:
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                    return provider
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        # grab a list of the providers we currently have
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        remaining = self.get_providers()
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        # if there are any
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        if remaining:
 
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            # try and sort them
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            self.ordered_providers = []
 
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            # loop through the names in the order specified
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            for name in order:
 
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                # try and find the class with the correct name
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                classx = find_by_name(name, remaining)
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                if classx:
 
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                    # if we found it, stick it in the list
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                    self.ordered_providers.append(classx)
 
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                    # and remove it from remaining
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                    remaining.remove(classx)
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                elif self.must_order:
 
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                    # if we didn't find it and must_order is on
 
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                    # then we need to stop
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                    raise ValueError(
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                        'must_order is True, '
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                        'but not all providers could be found')
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                else:
 
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                    # if must_order isn't on, then we can continue
 
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                    # but issue a warning
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                    logger.warning('could not find provider %s',
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                                   name)
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            if remaining:
 
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                # if there were left over providers, warn about them
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                logger.warning('not all providers for %s were ordered',
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                              self.servicename)
 
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                # and then tack them on the end
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                self.ordered_providers.extend(remaining)
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            logger.debug('providers for %s ordered: %s',
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    def get_preferred_provider(self):
 
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        # check to make sure they've been ordered
 
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        # and that there are actually providers
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        if hasattr(self, 'ordered_providers') and \
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           len(self.ordered_providers) > 0:
 
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            # if so, return the first one
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            return self.ordered_providers[0]
 
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        elif len(providers) == 0:
 
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            # no providers
 
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            logger.warning('no providers available')
 
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            # return None
 
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            return None
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        else:
 
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            # providers haven't been ordered
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            if self.must_order:
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                raise ValueError(
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                    'must_order is True, but providers are not ordered'
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                )
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            # get a list of the providers
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            providers = self.get_providers()
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            if len(providers) > 0:
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                logger.warning('returned random provider %s', providers[0])
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                # we haven't ordered them yet
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                return providers[0]
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            else:
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                logger.warning('no providers available')
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                return None
 
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            # warn that they haven't been sorted
 
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            logger.warning('returned random provider %s', providers[0])
 
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            # return the first one (it's random)
 
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            return providers[0]