Identity of Subscribers
A further use of the mechanism for identifying a subscribers identity, is so that subscriptions can be tracked and for processing or interception of data only to be undertaken while there are subscribers in- terested in the results. This avoids unnecessarily publishing reports when it is known there would be no one to send them to.
class LogMonitor(netsvc.Service): def __init__(self):
name = "logmon@%s" % netsvc.processIdentity() netsvc.Service.__init__(self,name) self._logger = netsvc.Logger() self._channels = {}
def notify(self,channel,level,message): agent =
report = {} report["agent"] = agent report["level"] = level report["message"] = message self.publishReport(agent,report)
def handleSubscription(self,subscription): agent = subscription.subject()
channel = "(%s)" % agent
if subscription.status() == netsvc.SUBSCRIPTION_REQUESTED: if len(agent) != 0:
subscriber = subscription.subscriber().agentIdentity() if not self._channels.has_key(channel):
self._channels[channel] = []
self._logger.monitorChannel(channel,self.notify) self._channels[channel].append(subscriber)
else:
if self._channels.has_key(channel):
subscriber = subscription.subscriber().agentIdentity() if subscriber in self._channels[channel]:
index = self._channels[channel].index(subscriber) del self._channels[channel][index]
if len(self._channels[channel]) == 0: del self._channels[channel] self._logger.monitorChannel(channel,None)
logger = netsvc.Logger()
class Publisher(netsvc.Service): def __init__(self):
netsvc.Service.__init__(self,"publisher") self._channel = "(%s)" % self.agentIdentity()
def debug(self,message): logger.notifyChannel(self._channel,netsvc.LOG_DEBUG,message)
In this use of subscription information, the subscription to a specific subject is used to trigger intercep- tion of messages logged via the logger interface. For the time that subscriptions exist for a particular
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