def welcomeIfNewNode(self, node):
"""
Given a new node, send it all the keys/values it should be storing,
then add it to the routing table.
@param node: A new node that just joined (or that we just found out
about).
Process:
For each key in storage, get k closest nodes. If newnode is closer
than the furtherst in that list, and the node for this server
is closer than the closest in that list, then store the key/value
on the new node (per section 2.5 of the paper)
"""
if self.router.isNewNode(node):
ds = []
for key, value in self.storage.iteritems():
keynode = Node(digest(key))
neighbors = self.router.findNeighbors(keynode)
if len(neighbors) > 0:
newNodeClose = node.distanceTo(keynode) < neighbors[-1].distanceTo(keynode)
thisNodeClosest = self.sourceNode.distanceTo(keynode) < neighbors[0].distanceTo(keynode)
if len(neighbors) == 0 or (newNodeClose and thisNodeClosest):
ds.append(self.callStore(node, key, value))
self.router.addContact(node)
return defer.gatherResults(ds)
def set(self, key, value):
"""
Set the given key to the given value in the network.
"""
self.log.debug("setting '%s' = '%s' on network" % (key, value))
dkey = digest(key)
node = Node(dkey)
def store(nodes):
self.log.info("setting '%s' on %s" % (key, list(map(str, nodes))))
# if this node is close too, then store here as well
if self.node.distanceTo(node) < max([n.distanceTo(node) for n in nodes]):
self.storage[dkey] = value
ds = [self.protocol.callStore(n, dkey, value) for n in nodes]
d = defer.DeferredList(ds)
d.addCallback(self._anyRespondSuccess)
d.addErrback(self.onError)
return d
nearest = self.protocol.router.findNeighbors(node)
if len(nearest) == 0:
self.log.warning("There are no known neighbors to set key %s" % key)
return defer.succeed(False)
spider = NodeSpiderCrawl(self.protocol, node, nearest, self.ksize, self.alpha)
d = spider.find()
d.addCallback(store)
d.addErrback(self.onError)
return d
def get(self, key):
"""
Get a key if the network has it.
Returns:
:class:`None` if not found, the value otherwise.
"""
dkey = digest(key)
# if this node has it, return it
if self.storage.get(dkey) is not None:
return defer.succeed(self.storage.get(dkey))
node = Node(dkey)
nearest = self.protocol.router.findNeighbors(node)
if len(nearest) == 0:
self.log.warning("There are no known neighbors to get key %s" % key)
return defer.succeed(None)
spider = ValueSpiderCrawl(self.protocol, node, nearest, self.ksize, self.alpha)
return spider.find()
def __init__(self, ksize=20, alpha=3, id=None, storage=None,
protocol=None, logger=None):
"""
Create a server instance. This will start listening on the given port.
Args:
ksize (int): The k parameter from the paper
alpha (int): The alpha parameter from the paper
id: The id for this node on the network.
storage: An instance that implements :interface:`~kademlia.storage.IStorage`
protocol: Optionally overrider default protocol.
logger: Optionally overrider default logger.
"""
self.ksize = ksize
self.alpha = alpha
self.log = logger or Logger(system=self)
self.protocol = protocol or KademliaProtocol(
Node(id or digest(random.getrandbits(255))),
storage or ForgetfulStorage(),
ksize
)
self.storage = self.protocol.storage
self.node = self.protocol.sourceNode
self.refreshLoop = LoopingCall(self.refreshTable).start(3600)
def test_digest(self):
d = hashlib.sha1(b'1').digest()
self.assertEqual(d, digest(1))
d = hashlib.sha1(b'another').digest()
self.assertEqual(d, digest('another'))
