def echo_case(self, echo_msg):
""" (ECHOMessage,) -> None
An execution when receiving an echo message.
"""
#TODO: assume that we won't receive an echo if we didn't initiate an explorer
# get variables from a message
invoke_id = echo_msg.get_id()
sender_name = echo_msg.get_sender_name()
logging.debug(
"From {0} with invoke id {1}, received an echo message".format(
sender_name, invoke_id))
# get the aggregator from a collection
aggregator = self.aggregator_collections[invoke_id]
# perform aggregate
aggregator.results = self.executor.aggregate(
aggregator.results, echo_msg.get_data(), aggregator.limit,
aggregator.aggregation_function_list)
# N := N-{from}
aggregator.remove_neighbor(sender_name)
# if N = zero_set
if len(aggregator.neighbors) == 0:
# return an echo message to parent
return_msg = ECHOMessage(ECHOMessage.MSG_TYPE_ECHO, invoke_id,
NAME, aggregator.results)
# return
self.senders[aggregator.parent].send(return_msg.serialize())
#clean up
self.aggregator_collections[invoke_id] = None
del aggregator
def invoke_case(self, invoke_msg):
""" (ECHOMessage,) -> None
An execution when receiving an invoke message.
"""
#TODO: assume that we won't invoke the same ID *
# get variables from a message
invoke_id = invoke_msg.get_id()
parent = invoke_msg.get_sender_name()
# create an aggregator object
aggregator = EchoAggregator(NEIGHBOR_LIST, parent)
# save it for future reference
self.aggregator_collections[invoke_id] = aggregator
#if N != zero_set
if len(aggregator.neighbors) != 0:
#change an invoke message to an explorer message
exp_msg = invoke_msg
exp_msg.msg_type = ECHOMessage.MSG_TYPE_EXP
exp_msg.sender = NAME
# send explorer messages
for host in aggregator.neighbors:
self.senders[host].send(exp_msg.serialize())
# A.initiate()
# get the query object
query = invoke_msg.get_data()
# add more information to echo aggregator
aggregator.limit = query.parameters['limit']
aggregator.aggregation_function_list = query.aggregation_function_list
# execute the result
results = self.executor.execute(query)
# store local results
aggregator.results = results
else:
# A.initiate()
# get the query object
query = invoke_msg.get_data()
# add more information to echo aggregator
aggregator.limit = query.parameters['limit']
aggregator.aggregation_function_list = query.aggregation_function_list
# execute the result
results = self.executor.execute(query)
# create a return message
return_msg = ECHOMessage(ECHOMessage.MSG_TYPE_RETURN, invoke_id,
NAME, results)
# return
self.senders[parent].send(return_msg.serialize())
# clean up
self.aggregator_collections[invoke_id] = None
del aggregator
def exp_case(self, exp_msg):
""" (ECHOMessage,) -> None
An execution when receiving an explorer message.
"""
# get variables from a message
invoke_id = exp_msg.get_id()
sender_name = exp_msg.get_sender_name()
logging.debug(
"From {0} with invoke id {1}, received an explorer message".format(
sender_name, invoke_id))
# create a socket to parent if not exist
if sender_name not in self.senders:
self.senders[sender_name] = self.context.socket(zmq.PUSH)
self.senders[sender_name].connect("tcp://{0}:{1}".format(
sender_name, DISPATCHER_PORT))
# get a aggregator object from the collection. if not exist, create it
try:
aggregator = self.aggregator_collections[invoke_id]
except KeyError:
aggregator = EchoAggregator(NEIGHBOR_LIST, sender_name)
# N := N-{from}
aggregator.remove_neighbor(sender_name)
# if not visited
if invoke_id not in self.aggregator_collections:
# save it for future reference
self.aggregator_collections[invoke_id] = aggregator
# create local result, and store it locally
# A.initiate()
# get a query object
query = exp_msg.get_data()
# add more information to echo aggregator
aggregator.limit = query.parameters['limit']
aggregator.aggregation_function_list = query.aggregation_function_list
# if there are neighbors
if len(aggregator.neighbors) != 0:
# change a sender name of a explorer message
exp_msg.sender = NAME
# broadcast explorer messages
for host in aggregator.neighbors:
self.senders[host].send(exp_msg.serialize())
# execute
results = self.executor.execute(query)
# store the result
aggregator.results = results
# if it is a leaf
else:
# execute
results = self.executor.execute(query)
# create a return message
echo_msg = ECHOMessage(ECHOMessage.MSG_TYPE_ECHO, invoke_id,
NAME, results)
# send to parent
self.senders[aggregator.parent].send(echo_msg.serialize())
#clean up
self.aggregator_collections[invoke_id] = None
del aggregator
# visited and N = zero_set
else:
if len(aggregator.neighbors) == 0:
# return an echo message to parent
echo_msg = ECHOMessage(ECHOMessage.MSG_TYPE_ECHO, invoke_id,
NAME, aggregator.results)
# return
self.senders[aggregator.parent].send(echo_msg.serialize())
#clean up
self.aggregator_collections[invoke_id] = None
del aggregator