def __init__(self, param):
self.logger = logging.getLogger(__name__)
# memento for state machine
self.memento = Memento(param['memento'])
self.memento.load()
# prepare database
self.spider = param['spider']
self.assembler = param['assembler']
self.feed_builder = param['feed_builder']
self.database = Database()
# all states are listed here
self.state_map = {
'InitialState' : InitialState(self),
'LoadState' : LoadState(self),
'SpiderState' : SpiderState(self),
'AssemblerState' : AssemblerState(self),
'DatabaseState' : DatabaseState(self),
'FinalState' : FinalState(self),
}
# set transition table
self.transition_table = param['transition_table']
# set current state
self.curr_state = 'InitialState'
class StateMachine():
def __init__(self, param):
self.logger = logging.getLogger(__name__)
# memento for state machine
self.memento = Memento(param['memento'])
self.memento.load()
# prepare database
self.spider = param['spider']
self.assembler = param['assembler']
self.feed_builder = param['feed_builder']
self.database = Database()
# all states are listed here
self.state_map = {
'InitialState' : InitialState(self),
'LoadState' : LoadState(self),
'SpiderState' : SpiderState(self),
'AssemblerState' : AssemblerState(self),
'DatabaseState' : DatabaseState(self),
'FinalState' : FinalState(self),
}
# set transition table
self.transition_table = param['transition_table']
# set current state
self.curr_state = 'InitialState'
def run(self):
while self.curr_state != 'FinalState':
try:
self.state_map[self.curr_state].run()
self.curr_state = self.next()
except KeyboardInterrupt:
self.state_map[self.curr_state].tear_down()
raise
def next(self):
transition_value = self.get_value('transition_value', '')
for entry in self.transition_table:
state, next_state, expected_value = entry
if (self.curr_state, transition_value) == (state, expected_value):
return next_state
self.logger.error('transition table is not completed')
return 'FinalState'
def get_value(self, key, default_value=None):
memento_value = self.memento.get_value()
if key in memento_value:
return memento_value[key]
else:
return default_value
def set_value(self, key, value):
memento_value = self.memento.get_value()
memento_value[key] = value
def save_memento(self):
self.memento.save()
