def decode(to_decode):
""" takes a string and parses it to construct a message class """
""" needs better methods for reinstantiating """
# verify checksum
rv = Message()
decoded_list = to_decode.split(DELIMITERS[ROOT_DELIM_INDEX])
rv.header = MessageHeader.decode(decoded_list[0])
rv.payloads = [MessagePayload.decode(x, int(rv.header.message_type))
for x in decoded_list[1].split(DELIMITERS[PAYLOAD_SEP_DELIM_INDEX])]
checksum = str(crc32(decoded_list[1]))
if checksum == decoded_list[2]:
pass
else:
raise Exception("Bad Checksum") # should be more informative
return rv
def __init__(self):
""" Default "constructor", creates placeholder variables. """
self.header = MessageHeader()
self.payloads = list()
class Message(WaggleDefaults):
assert ROOT_DELIM_INDEX != PAYLOAD_SEP_DELIM_INDEX
def __init__(self):
""" Default "constructor", creates placeholder variables. """
self.header = MessageHeader()
self.payloads = list()
def append(self, new_payload):
""" This function appends more payloads entry to the message """
if len(self.payloads) == 0:
self.header.message_type = str(new_payload.PAYLOAD_ID)
self.payloads.append(new_payload)
elif self.payloads[0].PAYLOAD_ID == new_payload.PAYLOAD_ID:
self.payloads.append(new_payload)
else:
raise TypeError("Mismatching payload type")
def encode(self):
""" Create a properly formatted message as a string. """
header_str = self.header.encode()
payloads_str = _encode([x.encode() for x in self.payloads], PAYLOAD_SEP_DELIM_INDEX)
checksum = str(crc32(payloads_str))
return _encode([header_str, payloads_str, checksum], ROOT_DELIM_INDEX)
@staticmethod
def decode(to_decode):
""" takes a string and parses it to construct a message class """
""" needs better methods for reinstantiating """
# verify checksum
rv = Message()
decoded_list = to_decode.split(DELIMITERS[ROOT_DELIM_INDEX])
rv.header = MessageHeader.decode(decoded_list[0])
rv.payloads = [MessagePayload.decode(x, int(rv.header.message_type))
for x in decoded_list[1].split(DELIMITERS[PAYLOAD_SEP_DELIM_INDEX])]
checksum = str(crc32(decoded_list[1]))
if checksum == decoded_list[2]:
pass
else:
raise Exception("Bad Checksum") # should be more informative
return rv
@staticmethod
def _DA_decode(to_decode, db_connector):
""" This decode function should be used by data agent ONLY!!
It introduces the db_connector so to enable unified database write function.
"""
obj = Message.decode(to_decode)
obj.db_connector = db_connector
return obj
def _push_to_db(self):
type_num = int(self.header.message_type)
part1 = "insert into sensor_data( protocol_version, inst_id, sequence_id, sensor_id"
part2 = "self.protocol_version, self.instance_id, self.sequence_id, self.timestamp"
#print 'Type:' +str(type_num)
#self.payloads
if RegistrationPayload.PAYLOAD_ID == type_num:
print type_num
pass
#
if DataPayload.PAYLOAD_ID == type_num: #
print type_num # print "data------------------"
#TODO: the database write function should be implemented in message or payload, if the payload can represent all information.
'''
leng = len(recs)
print 'record obj done, records list len = ' + str(leng)
for rec in recs:
rec.insert_to_cassandra(self.db_connector)
pass
'''
if ReplyPayload.PAYLOAD_ID == type_num:
print type_num
pass
if CommandPayload.PAYLOAD_ID == type_num:
print type_num
pass
def __str__(self):
""" Print a user friendly version of the payload. """
rv = str(self.header)
for i in xrange(len(self.payloads)):
rv = rv + "\nPayload[" + str(i) + "]:\n"
rv = rv + indented(str(self.payloads[i]))
return rv
