def __init__(self, portNumber):
self.portNumber = portNumber
self.keyValueMap = dict()
self.size = 0
self.identity = socket.gethostname().rstrip(".local")
self.identifier = int("0x"+hashlib.sha1(self.identity).hexdigest(),0) % pow(2,mEntries)
# initalize fingertable
self.fingerTable = FingerTable(mEntries)
class Node(NodeCommunication, NodeOperations):
def __init__(self, portNumber):
self.portNumber = portNumber
self.keyValueMap = dict()
self.size = 0
self.identity = socket.gethostname().rstrip(".local")
self.identifier = int("0x"+hashlib.sha1(self.identity).hexdigest(),0) % pow(2,mEntries)
# initalize fingertable
self.fingerTable = FingerTable(mEntries)
def join(self, predecessor):
# Join the system. Find my place
# corner case for first node
if predecessor == socket.gethostname().rstrip(".local"):
for i in range(0,mEntries):
self.fingerTable.new_entry(i, self.identifier, self.identity)
return
preIdentifier = int("0x"+hashlib.sha1(predecessor).hexdigest(),0) % pow(2,mEntries)
identifier = self.identifier
if preIdentifier > identifier:
identifier += pow(2, mEntries)+1
# find my place in the system
successor = self.request_successor(predecessor, self.portNumber, str(identifier))
# Calculate first finger and join the system
self.fingerTable.new_entry(0,self.identifier, successor)
# Update the predecessor
self.update_predecessor(self.fingerTable.get_succ_identity(), self.portNumber, self.fingerTable.get_succ_identity(), self.identity)
# Calculate the rest of the fingers
self.find_fingers(self.identifier, self.portNumber)
# send message to all others nodes, that they should update their finger table
self.update_others_finger_table(self.fingerTable.get_succ_identity(), self.portNumber, self.fingerTable.get_succ_identity(), self.identity)
# Calculate and find the fingers for the finger table
def find_fingers(self, identifier, portNumber):
for i in range(2, mEntries + 1):
value = int((identifier + pow(2,i-1)) % pow(2,mEntries))
if value < identifier:
value += pow(2,mEntries)+1
successor = self.check_corner_cases(value)
if successor is None:
successor = self.request_successor(self.fingerTable.get_succ_identity(), portNumber, str(value))
self.fingerTable.new_entry(i-1, identifier, successor)
# Function to check corner cases, very important when we pass the zero identifier
# might be easier with threaded connection
def check_corner_cases(self, identifier):
# only one node
if self.fingerTable.get_succ_identifier() == self.identifier:
identity = self.fingerTable.get_succ_identity()
return identity
if self.identifier > self.fingerTable.get_succ_identifier():
if identifier > pow(2,mEntries):
# well....
identifier -= (pow(2,mEntries)+1)
else:
if self.identifier >= identifier:
return self.identity
if self.identifier > identifier:
if self.fingerTable.get_succ_identifier() > identifier:
return self.fingerTable.get_succ_identity()
else:
return self.request_successor(self.fingerTable.get_succ_identity(), self.portNumber, str(identifier))
else:
return self.fingerTable.get_succ_identity()
return None