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._current = 0
  75
  76         def initialize_state(self):
  77                 self._current = self._min / 2
  78
  79         def increment_state(self):
  80                 if self._max == UpdateStateMachine.INFINITE_PERIOD:
  81                         self._current *= 2
  82                 else:
  83                         self._current = min(2 * self._current, self._max - self._init)
  84
  85         @property
  86         def timeout(self):
  87                 return self._init + self._current
  88
  89
  90 class StateMachine(object):
  91
  92         STATE_ACTIVE = 0, "active"
  93         STATE_IDLE = 1, "idle"
  94         STATE_DND = 2, "dnd"
  95
  96         def start(self):
  97                 raise NotImplementedError("Abstract")
  98
  99         def stop(self):
 100                 raise NotImplementedError("Abstract")
 101
 102         def close(self):
 103                 raise NotImplementedError("Abstract")
 104
 105         def set_state(self, state):
 106                 raise NotImplementedError("Abstract")
 107
 108         @property
 109         def state(self):
 110                 raise NotImplementedError("Abstract")
 111
 112
 113 class MasterStateMachine(StateMachine):
 114
 115         def __init__(self):
 116                 self._machines = []
 117                 self._state = self.STATE_ACTIVE
 118
 119         def append_machine(self, machine):
 120                 self._machines.append(machine)
 121
 122         def start(self):
 123                 # Confirm we are all on the same page
 124                 for machine in self._machines:
 125                         machine.set_state(self._state)
 126                 for machine in self._machines:
 127                         machine.start()
 128
 129         def stop(self):
 130                 for machine in self._machines:
 131                         machine.stop()
 132
 133         def close(self):
 134                 for machine in self._machines:
 135                         machine.close()
 136
 137         def set_state(self, state):
 138                 self._state = state
 139                 for machine in self._machines:
 140                         machine.set_state(state)
 141
 142         @property
 143         def state(self):
 144                 return self._state
 145
 146
 147 class UpdateStateMachine(StateMachine):
 148         # Making sure the it is initialized is finicky, be careful
 149
 150         INFINITE_PERIOD = -1
 151
 152         _IS_DAEMON = True
 153
 154         def __init__(self, updateItems, name=""):
 155                 self._name = name
 156                 self._updateItems = updateItems
 157
 158                 self._state = self.STATE_ACTIVE
 159                 self._timeoutId = None
 160
 161                 self._strategies = {}
 162                 self._callback = coroutines.func_sink(
 163                         coroutines.expand_positional(
 164                                 self._request_reset_timers
 165                         )
 166                 )
 167
 168         def set_state_strategy(self, state, strategy):
 169                 self._strategies[state] = strategy
 170
 171         def start(self):
 172                 assert self._timeoutId is None
 173                 for strategy in self._strategies.itervalues():
 174                         strategy.initialize_state()
 175                 self._timeoutId = gobject.idle_add(self._on_timeout)
 176                 _moduleLogger.info("%s Starting State Machine" % (self._name, ))
 177
 178         def stop(self):
 179                 self._stop_update()
 180
 181         def close(self):
 182                 self._callback = None
 183
 184         def set_state(self, newState):
 185                 if self._state == newState:
 186                         return
 187                 oldState = self._state
 188                 _moduleLogger.info("%s Transitioning from %s to %s" % (self._name, oldState, newState))
 189
 190                 self._state = newState
 191                 self._reset_timers()
 192
 193         @property
 194         def state(self):
 195                 return self._state
 196
 197         def reset_timers(self):
 198                 self._reset_timers()
 199
 200         @property
 201         def request_reset_timers(self):
 202                 return self._callback
 203
 204         @property
 205         def _strategy(self):
 206                 return self._strategies[self._state]
 207
 208         @gtk_toolbox.log_exception(_moduleLogger)
 209         def _request_reset_timers(self, *args):
 210                 self._reset_timers()
 211
 212         def _set_initial_period(self):
 213                 self._currentPeriod = self._INITIAL_ACTIVE_PERIOD / 2 # We will double it later
 214
 215         def _schedule_update(self):
 216                 assert self._timeoutId is None
 217                 self._strategy.increment_state()
 218                 nextTimeout = self._strategy.timeout
 219                 if nextTimeout != self.INFINITE_PERIOD:
 220                         self._timeoutId = gobject.timeout_add(nextTimeout, self._on_timeout)
 221                 _moduleLogger.info("%s Next update in %s ms" % (self._name, nextTimeout, ))
 222
 223         def _stop_update(self):
 224                 if self._timeoutId is None:
 225                         return
 226                 gobject.source_remove(self._timeoutId)
 227                 self._timeoutId = None
 228
 229         def _reset_timers(self):
 230                 if self._timeoutId is None:
 231                         return # not started yet
 232                 self._stop_update()
 233                 self._strategy.initialize_state()
 234                 self._schedule_update()
 235
 236         @gtk_toolbox.log_exception(_moduleLogger)
 237         def _on_timeout(self):
 238                 _moduleLogger.debug("%s Update" % (self._name))
 239                 for item in self._updateItems:
 240                         try:
 241                                 item.update(force=True)
 242                         except Exception:
 243                                 _moduleLogger.exception("Update failed for %r" % item)
 244                 self._timeoutId = None
 245                 self._schedule_update()
 246                 return False # do not continue