Source Code for Module sparked.monitors

  1  # Copyright (c) 2010 Arjan Scherpenisse 
  2  # See LICENSE for details. 
  3  # -*- test-case-name: sparked.test.test_monitors -*- 
  4   
  5  """ 
  6  Classes for monitoring the system's state. 
  7  """ 
  8   
  9  from twisted.application import service 
 10  from twisted.internet import reactor 
 11  from twisted.python import log 
 12   
 13  from sparked.hardware import power, network 
 14  from sparked.internet import zeroconf 
 15  from sparked import events 
 16   
 17   
 18   
 19 -class MonitorContainer (service.MultiService): 
 20      """ 
 21      A container for monitoring services. 
 22   
 23      @ivar monitors: A list of L{Monitor} objects. 
 24      @ivar events: An L{events.EventDispatcher} which triggers an "updated" event when one of the monitors state changes. 
 25      """ 
 26   
 27      monitors = None 
 28      events = None 
 29      verbose = False 
 30   
 31 -    def __init__(self): 
 32          service.MultiService.__init__(self) 
 33          self.events = events.EventDispatcher() 
 34          self.monitors = [] 
 35   
 36   
 37 -    def startService(self): 
 38          service.MultiService.startService(self) 
 39          reactor.callLater(0, self.update) 
 40   
 41   
 42 -    def addMonitor(self, monitor): 
 43          """ 
 44          Add a monitor to the container, and notify that the monitor has changed. 
 45          """ 
 46          self.monitors.append(monitor) 
 47          monitor.added(self) 
 48          self.update() 
 49   
 50   
 51 -    def removeMonitor(self, monitor): 
 52          """ 
 53          Remove a monitor from the container 
 54          """ 
 55          i = self.monitors.index(monitor) 
 56          self.monitors[i].removed(self) 
 57          del self.monitors[i] 
 58          self.update() 
 59   
 60   
 61 -    def update(self): 
 62          """ 
 63          Notify the container that monitor state has been changed or the monitors have been modified. 
 64          """ 
 65          self.events.dispatch("updated", self) 
 66          if self.verbose: 
 67              log.msg("= STATUS =====================") 
 68              for m in self.monitors: 
 69                  if m.ok: 
 70                      stat = "ok" 
 71                  else: 
 72                      stat = "FAIL" 
 73                  log.msg("%-26s%4s" % (m.title, stat)) 
 74              log.msg("==============================") 
 75   
 76   
 77 -    def ok(self): 
 78          for m in self.monitors: 
 79              if not m.ok: return False 
 80          return True 
 81   
 82   
 83 -class Monitor(object): 
 84      """ 
 85      A generic monitor 
 86   
 87      @ivar ok:  Boolean flag which tells if the monitor's state is 'ok' or not. 
 88      """ 
 89   
 90      ok = False 
 91   
 92 -    def added(self, container): 
 93          """ 
 94          Called when monitor is added to container. The container can 
 95          be used to hook services to. 
 96          """ 
 97          pass 
 98   
 99 -    def removed(self, container): 
100          """ 
101          Called when monitor is removed from container. The container can 
102          be used to hook services to. 
103          """ 
104          pass 
105   
106   
107   
108 -class PowerMonitor (Monitor): 
109      title = "Computer power" 
110   
111 -    def added(self, container): 
112          self.container = container 
113          self.svc = power.PowerService() 
114          self.svc.setServiceParent(container) 
115          power.powerEvents.addObserver("available", self.powerEvent) 
116   
117   
118 -    def removed(self): 
119          self.svc.disownServiceParent() 
120   
121   
122 -    def powerEvent(self, available): 
123          if available != self.ok: 
124              self.ok = available 
125              self.container.update() 
126   
127   
128   
129 -class NetworkMonitor(Monitor): 
130      title = "Network connection" 
131   
132 -    def added(self, container): 
133          self.container = container 
134          self.svc = network.NetworkConnectionService() 
135          self.svc.setServiceParent(container) 
136          network.networkEvents.addObserver("connected", self.event) 
137   
138   
139 -    def removed(self): 
140          self.svc.disownServiceParent() 
141   
142   
143 -    def event(self, connected): 
144          if connected != self.ok: 
145              self.ok = connected 
146              self.container.update() 
147   
148   
149   
150 -class NetworkWebMonitor(Monitor): 
151      title = "Internet connection" 
152   
153 -    def added(self, container): 
154          self.container = container 
155          self.svc = network.NetworkWebConnectionService() 
156          self.svc.setServiceParent(container) 
157          network.networkEvents.addObserver("web-connected", self.event) 
158   
159   
160 -    def removed(self): 
161          self.svc.disownServiceParent() 
162   
163   
164 -    def event(self, connected): 
165          if connected != self.ok: 
166              self.ok = connected 
167              self.container.update() 
168   
169   
170   
171 -class NamedZeroconfMonitor(Monitor): 
172      """ 
173      Monitor which is 'ok' when it has detected a service with given 
174      type and name. 
175   
176      @ivar type: The service type that needs to be matched. E.g. C{_daap._tcp}. 
177      @ivar name: The service name that needs to be matched. E.g. C{Arjan's Music}. 
178      """ 
179   
180 -    def __init__(self, name, type): 
181          self.name = name 
182          self.title = name 
183          self.type = type 
184   
185   
186 -    def added(self, container): 
187          self.container = container 
188          zeroconf.zeroconfService.subscribeTo(self.type) 
189          zeroconf.zeroconfEvents.addObserver("service-found", self._found) 
190          zeroconf.zeroconfEvents.addObserver("service-lost", self._lost) 
191   
192   
193 -    def _found(self, name, **kw): 
194          if kw['type'] == self.type and name == self.name: 
195              self.ok = True 
196              self.container.update() 
197   
198   
199 -    def _lost(self, name, **kw): 
200          if kw['type'] == self.type and name == self.name: 
201              self.ok = False 
202              self.container.update() 
203