class Site:
def __init__(self, site_id):
self._id = site_id
self._status = SiteStatus.UP
self._init_variables()
self._lm = LockManager(self._site_variables.keys())
def _init_variables(self):
self._site_variables = {}
for i in xrange(1, 21):
var_id = 'x' + str(i)
# value = int('10' + str(i))
value = 10 * i
if i % 2 == 0: # Even numbered variables are replicated
self._site_variables[var_id] = Variable(var_id, value)
elif (i + 1) % 10 == self._id:
self._site_variables[var_id] = Variable(var_id, value)
def get_id(self):
return self._id
def dump(self, var=None):
if var:
if var in self._site_variables:
return {var: self._site_variables[var].read_committed()}
print 'Variable doesn\'t exist on site'
else:
var_dict = {}
for var, obj in self._site_variables.iteritems():
var_dict[var] = obj.read_committed()
return var_dict
def dump_state(self):
return self._site_variables
def _load_state(self, state):
for var_id, var_obj in state.iteritems():
if var_id in self._site_variables:
uncommitted_values = var_obj.dump_uncommitted()
committed_values = var_obj.dump_committed()
new_var_obj = Variable(var_id, committed_values[0])
new_var_obj.load_state(committed_values, uncommitted_values)
self._site_variables[var_id] = new_var_obj
def is_up(self):
return self._status == SiteStatus.UP
def fail(self):
if self.is_up():
self._status = SiteStatus.DOWN
self._lm.release_all_locks()
def recover(self, state):
if not self.is_up():
#self._load_state(state)
for var_id, var_obj in self._site_variables.iteritems():
if var_obj.is_replicated():
var_obj.recover()
self._status = SiteStatus.UP
def write(self, transaction, variable, value):
if variable in self._site_variables:
self._lm.acquire_write_lock(transaction, variable)
self._site_variables[variable].write(transaction, value)
else:
print 'Variable doesn\'t exist on site'
def read(self, transaction, var_id):
if var_id in self._site_variables:
if self._site_variables[var_id].is_recovering():
return None
if self._lm.txn_has_write_lock(transaction, var_id):
return self._site_variables[var_id].read_uncommitted(
transaction)
else:
if transaction.get_type() != TransactionType.READ_ONLY:
self._lm.acquire_read_lock(transaction, var_id)
return self._site_variables[var_id].read_committed(transaction)
else:
return None
def commit(self, transaction, timestamp):
for var in self._site_variables.keys():
if self._lm.txn_has_write_lock(transaction, var):
self._site_variables[var].commit(timestamp)
self._lm.release_all_locks(transaction)
def abort(self, transaction):
self._lm.release_all_locks(transaction)
class Site:
def __init__(self, site_id):
self._id = site_id
self._status = SiteStatus.UP
self._init_variables()
self._lm = LockManager(self._site_variables.keys())
def _init_variables(self):
self._site_variables = {}
for i in xrange(1, 21):
var_id = 'x' + str(i)
# value = int('10' + str(i))
value = 10 * i
if i % 2 == 0: # Even numbered variables are replicated
self._site_variables[var_id] = Variable(var_id, value)
elif (i + 1) % 10 == self._id:
self._site_variables[var_id] = Variable(var_id, value)
def get_id(self):
return self._id
def dump(self, var=None):
if var:
if var in self._site_variables:
return {var: self._site_variables[var].read_committed()}
print 'Variable doesn\'t exist on site'
else:
var_dict = {}
for var, obj in self._site_variables.iteritems():
var_dict[var] = obj.read_committed()
return var_dict
def dump_state(self):
return self._site_variables
def _load_state(self, state):
for var_id, var_obj in state.iteritems():
if var_id in self._site_variables:
uncommitted_values = var_obj.dump_uncommitted()
committed_values = var_obj.dump_committed()
new_var_obj = Variable(var_id, committed_values[0])
new_var_obj.load_state(committed_values, uncommitted_values)
self._site_variables[var_id] = new_var_obj
def is_up(self):
return self._status == SiteStatus.UP
def fail(self):
if self.is_up():
self._status = SiteStatus.DOWN
self._lm.release_all_locks()
def recover(self, state):
if not self.is_up():
#self._load_state(state)
for var_id, var_obj in self._site_variables.iteritems():
if var_obj.is_replicated():
var_obj.recover()
self._status = SiteStatus.UP
def write(self, transaction, variable, value):
if variable in self._site_variables:
self._lm.acquire_write_lock(transaction, variable)
self._site_variables[variable].write(transaction, value)
else:
print 'Variable doesn\'t exist on site'
def read(self, transaction, var_id):
if var_id in self._site_variables:
if self._site_variables[var_id].is_recovering():
return None
if self._lm.txn_has_write_lock(transaction, var_id):
return self._site_variables[var_id].read_uncommitted(transaction)
else:
if transaction.get_type() != TransactionType.READ_ONLY:
self._lm.acquire_read_lock(transaction, var_id)
return self._site_variables[var_id].read_committed(transaction)
else:
return None
def commit(self, transaction, timestamp):
for var in self._site_variables.keys():
if self._lm.txn_has_write_lock(transaction, var):
self._site_variables[var].commit(timestamp)
self._lm.release_all_locks(transaction)
def abort(self, transaction):
self._lm.release_all_locks(transaction)
