git.maemo.org Git - theonering/blob - src/gvoice/state_machine.py

   1 #!/usr/bin/env python
   2
   3 """
   4 @todo Look into switching from POLL_TIME = min(F * 2^n, MAX) to POLL_TIME = min(CONST + F * 2^n, MAX)
   5 @todo Look into supporting more states that have a different F and MAX
   6 """
   7
   8 import logging
   9
  10 import gobject
  11
  12 import util.go_utils as gobject_utils
  13 import util.coroutines as coroutines
  14 import gtk_toolbox
  15
  16
  17 _moduleLogger = logging.getLogger("gvoice.state_machine")
  18
  19
  20 def to_milliseconds(**kwd):
  21         if "milliseconds" in kwd:
  22                 return kwd["milliseconds"]
  23         elif "seconds" in kwd:
  24                 return kwd["seconds"] * 1000
  25         elif "minutes" in kwd:
  26                 return kwd["minutes"] * 1000 * 60
  27         elif "hours" in kwd:
  28                 return kwd["hours"] * 1000 * 60 * 60
  29         raise KeyError("Unknown arg: %r" % kwd)
  30
  31
  32 class NopStateStrategy(object):
  33
  34         def __init__(self):
  35                 pass
  36
  37         def initialize_state(self):
  38                 pass
  39
  40         def increment_state(self):
  41                 pass
  42
  43         @property
  44         def timeout(self):
  45                 return UpdateStateMachine.INFINITE_PERIOD
  46
  47
  48 class ConstantStateStrategy(object):
  49
  50         def __init__(self, timeout):
  51                 assert 0 < timeout or timeout == UpdateStateMachine.INFINITE_PERIOD
  52                 self._timeout = timeout
  53
  54         def initialize_state(self):
  55                 pass
  56
  57         def increment_state(self):
  58                 pass
  59
  60         @property
  61         def timeout(self):
  62                 return self._timeout
  63
  64
  65 class GeometricStateStrategy(object):
  66
  67         def __init__(self, init, min, max):
  68                 assert 0 < init and init < max and init != UpdateStateMachine.INFINITE_PERIOD
  69                 assert 0 < min and min != UpdateStateMachine.INFINITE_PERIOD
  70                 assert min < max or max == UpdateStateMachine.INFINITE_PERIOD
  71                 self._min = min
  72                 self._max = max
  73                 self._init = init
  74                 self._actualInit = init
  75                 self._current = 0
  76
  77         def initialize_state(self):
  78                 self._current = self._min / 2
  79                 self._actualInit = self._init - self._min
  80
  81         def increment_state(self):
  82                 if self._max == UpdateStateMachine.INFINITE_PERIOD:
  83                         self._current *= 2
  84                 else:
  85                         self._current = min(2 * self._current, self._max - self._init)
  86
  87         @property
  88         def timeout(self):
  89                 return self._actualInit + self._current
  90
  91
  92 class StateMachine(object):
  93
  94         STATE_ACTIVE = 0, "active"
  95         STATE_IDLE = 1, "idle"
  96         STATE_DND = 2, "dnd"
  97
  98         def start(self):
  99                 raise NotImplementedError("Abstract")
 100
 101         def stop(self):
 102                 raise NotImplementedError("Abstract")
 103
 104         def close(self):
 105                 raise NotImplementedError("Abstract")
 106
 107         def set_state(self, state):
 108                 raise NotImplementedError("Abstract")
 109
 110         @property
 111         def state(self):
 112                 raise NotImplementedError("Abstract")
 113
 114
 115 class MasterStateMachine(StateMachine):
 116
 117         def __init__(self):
 118                 self._machines = []
 119                 self._state = self.STATE_ACTIVE
 120
 121         def append_machine(self, machine):
 122                 self._machines.append(machine)
 123
 124         def start(self):
 125                 # Confirm we are all on the same page
 126                 for machine in self._machines:
 127                         machine.set_state(self._state)
 128                 for machine in self._machines:
 129                         machine.start()
 130
 131         def stop(self):
 132                 for machine in self._machines:
 133                         machine.stop()
 134
 135         def close(self):
 136                 for machine in self._machines:
 137                         machine.close()
 138
 139         def set_state(self, state):
 140                 self._state = state
 141                 for machine in self._machines:
 142                         machine.set_state(state)
 143
 144         @property
 145         def state(self):
 146                 return self._state
 147
 148
 149 class UpdateStateMachine(StateMachine):
 150         # Making sure the it is initialized is finicky, be careful
 151
 152         INFINITE_PERIOD = -1
 153
 154         _IS_DAEMON = True
 155
 156         def __init__(self, updateItems, name=""):
 157                 self._name = name
 158                 self._updateItems = updateItems
 159
 160                 self._state = self.STATE_ACTIVE
 161                 self._timeoutId = None
 162
 163                 self._strategies = {}
 164                 self._callback = coroutines.func_sink(
 165                         coroutines.expand_positional(
 166                                 self._request_reset_timers
 167                         )
 168                 )
 169
 170         def set_state_strategy(self, state, strategy):
 171                 self._strategies[state] = strategy
 172
 173         def start(self):
 174                 assert self._timeoutId is None
 175                 for strategy in self._strategies.itervalues():
 176                         strategy.initialize_state()
 177                 self._timeoutId = gobject.idle_add(self._on_timeout)
 178                 _moduleLogger.info("%s Starting State Machine" % (self._name, ))
 179
 180         def stop(self):
 181                 self._stop_update()
 182
 183         def close(self):
 184                 self._callback = None
 185
 186         def set_state(self, newState):
 187                 if self._state == newState:
 188                         return
 189                 oldState = self._state
 190                 _moduleLogger.info("%s Transitioning from %s to %s" % (self._name, oldState, newState))
 191
 192                 self._state = newState
 193                 self._reset_timers()
 194
 195         @property
 196         def state(self):
 197                 return self._state
 198
 199         def reset_timers(self):
 200                 self._reset_timers()
 201
 202         @property
 203         def request_reset_timers(self):
 204                 return self._callback
 205
 206         @property
 207         def _strategy(self):
 208                 return self._strategies[self._state]
 209
 210         @gobject_utils.async
 211         @gtk_toolbox.log_exception(_moduleLogger)
 212         def _request_reset_timers(self, *args):
 213                 self._reset_timers()
 214
 215         def _set_initial_period(self):
 216                 self._currentPeriod = self._INITIAL_ACTIVE_PERIOD / 2 # We will double it later
 217
 218         def _schedule_update(self):
 219                 assert self._timeoutId is None
 220                 self._strategy.increment_state()
 221                 nextTimeout = self._strategy.timeout
 222                 if nextTimeout != self.INFINITE_PERIOD:
 223                         self._timeoutId = gobject.timeout_add(nextTimeout, self._on_timeout)
 224                 _moduleLogger.info("%s Next update in %s ms" % (self._name, nextTimeout, ))
 225
 226         def _stop_update(self):
 227                 if self._timeoutId is None:
 228                         return
 229                 gobject.source_remove(self._timeoutId)
 230                 self._timeoutId = None
 231
 232         def _reset_timers(self):
 233                 if self._timeoutId is None:
 234                         return # not started yet
 235                 self._stop_update()
 236                 self._strategy.initialize_state()
 237                 self._schedule_update()
 238
 239         @gtk_toolbox.log_exception(_moduleLogger)
 240         def _on_timeout(self):
 241                 _moduleLogger.debug("%s Update" % (self._name))
 242                 for item in self._updateItems:
 243                         try:
 244                                 item.update(force=True)
 245                         except Exception:
 246                                 _moduleLogger.exception("Update failed for %r" % item)
 247                 self._timeoutId = None
 248                 self._schedule_update()
 249                 return False # do not continue