def find_successor(self,
key: int,
start_key: int,
count: int = 0,
use_fingers=True) -> ('Node', str):
msg = ""
# Check if the key is between us an our successor.
# If that is the case we are done and can return the
# successor.
if in_interval(self.key, self.successor.key, key):
return self.successor, "Found using self successor", count
# Also check the predecessor
if self.predecessor is not None:
if in_interval(self.predecessor.key, self.key, key):
return Node(self.ip,
self.port), "Found using self predecessor", count
# Trying finger tables first if enabled
if use_fingers:
finger_result, msg, finger_count = self._use_fingertable(
key, start_key, count)
if finger_result is not None:
return finger_result, msg, finger_count
# Finger table did not return a result or is not enabled
# Trying slow method to move forward
slow_result, msg_slow, slow_count = self._slow_successor(
key, start_key, count)
if slow_result is not None:
return slow_result, msg_slow + " : " + msg, slow_count
return None, "Everything failed (returned None): " + msg_slow + " : " + msg, count
def give_photons(self, key: int):
result = [
x.photon_id for x in self.photons
if in_interval(self.key, key, x.key)
]
self.photons = [
x for x in self.photons if not in_interval(self.key, key, x.key)
]
print(self.port, "Photons left: ", self.photons)
print(self.port, "Giving photons to: ", key, result)
return result
def closest_preceding_finger(self, key: int):
for i in range(self.max_i, -1, -1):
if in_interval(self.key, key, self.keys[i]):
if not self.fingers[i]:
continue
return self.fingers[i]
return None
def stabilize(self):
# clear last request key
self.last_request_key = None
self.last_request_owner = []
if self.key != self.successor.key:
x = None
# Request successor for it's predecessor
url = 'http://{0}:{1}/predecessor'.format(self.successor.ip,
self.successor.port)
try:
data = json.loads(requests.get(url).text)
except:
self.set_new_successor()
data = None
if data is not None:
if data['predecessor']:
x = Node(data['ip'], data['port'])
if x and in_interval(self.key, self.successor.key, x.key):
self.successor = x
url = 'http://{0}:{1}/notify'.format(self.successor.ip,
self.successor.port)
requests.post(url, data={
'ip': self.ip,
'port': self.port
}) # TODO: perhaps check for answer?
else:
if self.predecessor and in_interval(self.key, self.successor.key,
self.predecessor.key):
self.successor = self.predecessor
self.notify(self)
self.finger_table.update_finger(0, self.successor)
def notify(self, node: 'Node'):
if not self.predecessor or in_interval(self.predecessor.key, self.key,
node.key):
self.predecessor = node