def __init__(self, node, peersParams):
""" Constructor
node : node using this manager
peersParams : initialization parameters of the peer manager, a list
[entitiesFileName, maxPeers, logger]
"""
self.node = node
self.entitiesFileName = peersParams[0]
self.maxPeers = peersParams[1]
self.logger = peersParams[2]
# hash table of peers indexed by ID
self.peers = {}
# clountercloclwise ordered list of peers
self.ccwPeers = CcwList()
# distance ordered list of peers
self.distPeers = DistList()
class PeersManager:
""" Manage all the neighbours of a node """
def __init__(self, node, peersParams):
""" Constructor
node : node using this manager
peersParams : initialization parameters of the peer manager, a list
[entitiesFileName, maxPeers, logger]
"""
self.node = node
self.entitiesFileName = peersParams[0]
self.maxPeers = peersParams[1]
self.logger = peersParams[2]
# hash table of peers indexed by ID
self.peers = {}
# clountercloclwise ordered list of peers
self.ccwPeers = CcwList()
# distance ordered list of peers
self.distPeers = DistList()
def createPeer(self, netAddress):
""" create a new Peer object
netAddress : the network address of this peer, e.g. '193.168.25.36:2456'
Return a Peer object"""
host = netAddress.getHost()
port = netAddress.getPort()
p = Peer('', host, port)
p.createId()
return p
def getRandomPeer(self):
""" Return a peer randomly chosen from a file
Read the entities file and return a random peer
"""
try:
f = file(self.entitiesFileName, 'r')
# read file
list = f.readlines()
# retrieve peer
peer = random.choice(list)
host, stringPort = string.splitfields(peer)
port = int(stringPort)
address = Address(host, port)
f.close()
except:
self.logger.critical("Cannot read file " + self.entitiesFileName)
raise
p = Peer('', host, port)
p.createId()
return p
def addPeer(self, p):
""" add a new peer
p : a peer object
"""
referencePosition = self.node.position
p.setLocalPosition(referencePosition)
id = p.getId()
if not id:
raise SolipsisInternalError("Error peer has no id")
if self.peers.has_key(id):
raise SolipsisInternalError("Error duplicate peer id:" + id)
self.peers[p.getId()] = p
self.ccwPeers.insert(p)
self.distPeers.insert(p)
def removePeer(self, p):
""" remove a peer
p : peer to remove """
id = p.getId()
if not id:
raise SolipsisInternalError("Error peer has no id")
if not self.peers.has_key(id):
raise SolipsisInternalError("Error removing peer - no peer with id:" + id)
del self.peers[id]
self.ccwPeers.delete(p)
self.distPeers.delete(p)
def updatePeer(self, p):
""" update information on a peer. """
self.removePeer(p)
self.addPeer(p)
def getPeer(self, address):
""" Return the peer associated with this net address """
# TODO check exception if this peer doesn't exist
id = address.toString()
return self.peers[id]
def heartbeat(self, id):
""" Update status of a peer
id : id of the peer that sent us a HEARTBEAT message
"""
peer = self.peers[id]
peer.setActiveTime(time.time())
def getPeerFromAddress(self, address):
""" Get the peer with address 'address'
address: address of the peer we are looking for - Address object
Return : a peer, or None if no such peer was found
"""
# Iterate through list of peers
ids = self.peers.keys()
for id in ids:
p = self.peers[id]
if p.address.toString() == address.toString():
return p
# no peer with this address was found
return None
def getClosestPeer(self, target):
""" Return the peer that is the closest to a target position
"""
closestPeer = self.peers.values()[0]
for p in self.peers.values():
if p.isCloser(closestPeer, target):
closestPeer = p
return closestPeer
def getPeerAround(self, nodePosition, targetPosition):
""" Return the peer that is the closest to a target position and that
is in the right half plane.
nodePosition : position of the node asking for a peer around
targetPosition : target position which we are looking around
Return : a peer
or None if there is no peer in the right half plane
"""
found = False
around = None
distClosest = 0
for p in self.peers.values():
if Geometry.inHalfPlane(nodePosition, targetPosition, p.position):
# first entity in right half-plane
if not found:
found = True
around = p
distClosest = Geometry.distance(targetPosition, p.position)
else:
dist = Geometry.distance(targetPosition, p.position)
# this peer is closer
if dist < distClosest:
around = p
distClosest = dist
return around
def hasTooManyPeers(self):
""" Check if we have too many neighbours
Return True if we have too many peers"""
return len(self.peers) > self.maxPeers
def getWorstPeer(self):
""" Choose a peer for removal. Removing this must NOT break the global
connectivity rule. """
# filter list of neighbors
# keep only entities not in Awareness Area which do not provoke mis-respect
# of Global Connectivity Rule
FilterList = []
endFilter = 1
indexFilter = self.distPeers.length - 1
nodePos = self.node.position
while endFilter and indexFilter > 0:
ent = self.distPeers.ll[indexFilter]
distEnt = Geometry.distance(ent.position, nodePos)
# first, verify that ent is not in Awareness Area
if distEnt > self.node.awarenessRadius :
if distEnt > ent.awarenessRadius:
indInCcw = self.ccwPeers.ll.index(ent)
successor = self.ccwPeers.ll[(indInCcw + 1) % self.ccwPeers.length]
predecessor = self.ccwPeers.ll[indInCcw - 1]
# then verify that ent is not mandatory for Rule respect
if Geometry.inHalfPlane(predecessor.position, nodePos,
successor.position):
FilterList.append(ent)
else:
# stop iteration because all following entities are in Awareness Radius
endFilter = 0
indexFilter -= 1
if FilterList <> []:
# there is a posibility to remove any entity in FilterList.
# By default, we decide to remove the farthest entity.
# In article presented at RESH'02, we proposed several other possibilities
# for more efficient choice.
result = FilterList[0]
else:
result = 0
return result
def enumerate(self):
""" return a list with all peers """
return self.distPeers
def update(self):
""" position of the node has changed rrecompute all neighbours postion """
self.logger.critical("manager.update NOT IMPLEMENTED")
raise SolipsisInternalError("manager.update NOT IMPLEMENTED")