def sendto(self, identity, data, timeout=30):
'''Send a single data object to the remote peer in datagram mode.'''
values = yield self.get(guid=H(identity))
for value in map(lambda x: x.value, values):
try:
value = int(value)
except:
print 'invalid non-integer value=%r' % (value)
continue
seq = dht._seq = dht._seq + 1
net = self.net
request = Message(name='Datagram:Request',
src=net.node,
dest=value,
seq=seq,
sock=hasattr(self, 'identity') and self.identity
or None,
peer=identity,
value=str(data))
if value == net.node.guid: yield net.put(request, timeout=timeout)
elif self.isSuperNode:
yield net.put(Message(name='Route:Request',
src=net.node,
dest=value,
payload=request),
timeout=timeout)
else:
yield net.send(Message(name='Proxy:Request',
src=net.node,
payload=request),
node=self.client.neighbors[0])
raise StopIteration(None)
def get(self, guid, maxvalues=16, Kp=None, timeout=5):
'''Invoke the get method on the connected DHT node if this is a client.'''
if self.server or not self.neighbors:
if _debug: print 'client.get not a client with valid connections'
raise StopIteration([])
net = self.net
seq = dht._seq = dht._seq + 1
request = Message(name='Get:Request',
seq=seq,
src=net.node,
dest=guid,
maxvalues=maxvalues,
hash=Kp and H(str(Kp)) or None)
yield net.send(Message(name='Proxy:Request',
src=net.node,
payload=request),
node=self.neighbors[0],
timeout=5)
response = yield net.get(timeout=timeout,
criteria=lambda x: x.seq == seq and x.name ==
'Get:Response') # wait for response
result = [(v.value, k.nonce, v.Kp, k.expires) for k, v in zip(
response.get('keyss', [None] *
len(response['vals'])), response['vals'])
] if response else []
raise StopIteration(
result
) # don't use response.values as it is a built-in method of base class dict of Message.
def pinghandler(self):
'''Respond to Ping:Request.'''
while True:
msg = yield self.net.get(lambda x: x.name == 'Ping:Request')
if _debug: print 'received ping request'
yield self.net.send(msg=Message(name='Ping:Response'),
node=msg.remote)
def put(self, guid, value, nonce, expires, Ks=None, put=True, timeout=30):
'''Forward the put request to the connected DHT node.'''
if self.server or not self.neighbors: # this is a server, or doesn't have valid connections
if _debug: print 'client.put not a client with valid connections'
raise StopIteration(False)
net = self.net
seq = dht._seq = dht._seq + 1
request = Message(name='Put:Request', date=time.time(), seq=seq, src=net.node, dest=guid, nonce=nonce, expires=expires, put=put, \
value=str(value) if put else None, hash=H(str(value)), Kp=Ks and dht.extractPublicKey(Ks) or None, \
sigma=dht.sign(Ks, H(str(guid) + str(value) + str(nonce) + str(expires))) if Ks else None)
yield net.send(Message(name='Proxy:Request',
src=net.node,
payload=request),
node=self.neighbors[0],
timeout=5)
response = yield net.get(timeout=timeout,
criteria=lambda x: x.seq == seq and x.name ==
'Put:Response') # wait for response
raise StopIteration(response and response.result)
def parse(self, data, addr, type):
'''Parse a message from given remote (host, port) and return parsed Message and remote Node.
Returns None as message if can't be parsed.'''
if len(data) < Hsize: return (None, None)
guid, data = dht.bin2int(data[0:Hsize]), data[Hsize:]
node = Node(ip=addr[0], port=addr[1], type=type, guid=guid)
try:
msg = Message(raw=data)
except:
return (None, None)
return (msg, node)
def connect(self, identity, timeout=30):
'''Connect to the given identity. It returns a Socket object on success or None on error.'''
values = yield self.get(guid=H(identity))
if _debug: print 'connect() found values=%r' % (values)
for value in map(lambda x: x.value, values):
try:
value = int(value)
except:
print 'invalid non-integer value=%r' % (value)
continue
sock = Socket(sock=self, peer=(identity, value), server=False)
seq = dht._seq = dht._seq + 1
net = self.net
request = Message(name='Connect:Request',
src=net.node,
dest=value,
seq=seq,
sock=hasattr(self, 'identity') and self.identity
or None,
peer=identity)
if value == net.node.guid: yield net.put(request, timeout=5)
elif self.isSuperNode:
yield net.put(Message(name='Route:Request',
src=net.node,
dest=value,
payload=request),
timeout=5)
else:
yield net.send(Message(name='Proxy:Request',
src=net.node,
payload=request),
node=self.client.neighbors[0])
response = yield net.get(
timeout=timeout,
criteria=lambda x: x.seq == seq and x.name ==
'Connect:Response') # wait for response
if response: raise StopIteration(sock)
else: sock.close()
raise StopIteration(None)
def requesthandler(msg):
p = msg.payload
response = None
if self.server: # only if a server
if p.name == 'Put:Request':
result = yield dht.put(net, p.dest, p.value, p.nonce,
p.expires, p.Ks, p.put)
response = Message(name='Put:Response',
seq=p.seq,
result=result)
elif p.name == 'Get:Request':
result = yield dht.get(net, p.dest, p.maxvalues, p.Kp)
response = Message(name='Get:Response',
seq=p.seq,
guid=p.guid,
vals=result)
if response:
yield self.net.send(Message(name='Proxy:Response',
src=net.node,
payload=response),
node=msg.src,
timeout=5)
def accept(self, timeout=None):
'''Accept an incoming connection. It returns a Socket object on success or None on error.'''
net = self.net
msg = yield net.get(timeout=timeout,
criteria=lambda x: x.name == 'Connect:Request' and
x.peer == self.identity) # wait for request
if _debug: print 'accept msg=%r' % (msg)
if not msg: raise StopIteration(None)
sock = Socket(sock=self, peer=(msg.sock, msg.src.guid), server=True)
yield net.send(Message(name='Connect:Response',
seq=msg.seq,
result=True),
node=msg.src)
raise StopIteration(sock)
def discoverhandler(self, timeout=3):
'''Respond to a Discover:Request message, for both multicast and unicast.'''
while True:
msg = yield self.net.get(lambda x: x.name == 'Discover:Request')
if _debug: print 'received discover request'
if msg.remote.hostport == self.net.node.hostport:
if _debug: print 'discoverhandler() ignoring our own packet'
continue # don't compare Node but only hostport. Ignore if our packet.
if msg.multicast: # wait randomly before replying to multicast discover
if _debug:
print 'discoverhandler() wait before responding to multicast'
response = yield self.net.get(
lambda x: x.name == 'Discover:Response' and x.multicast,
timeout=(random.random() + 0.5) * timeout)
if response: # someone else sent a response, we don't have to send anymore
continue
neighbors = ([self.net.node, self.net.nodetcp]
if self.server else []) + self.neighbors
if not msg.multicast or neighbors:
response = Message(name='Discover:Response',
neighbors=neighbors)
dest = (msg.remote
if not msg.multicast else self.net.nodemcast)
yield self.net.send(msg=response, node=dest)
def bootstrap(self, timeout=5, interval=30):
'''A generator to perform bootstrap function.'''
candidates = self.candidates[:] # a copy of list of candidates
while True:
if _debug:
print self.net.name, 'bootstrap server=', self.server, 'neighbors=', len(
self.neighbors), 'candidates=', len(candidates)
if not self.server and not self.neighbors and candidates: # more candidates but no more neighbors
node = candidates.pop(0)
if _debug: print 'bootstrap trying node=', repr(node)
if node.type == socket.SOCK_DGRAM and isMulticast(node.ip):
yield self.net.send(Message(name='Discover:Request'),
node=node)
msg = yield self.net.get(
lambda x: x.name == 'Discover:Response' and x.
multicast,
timeout=timeout)
else:
if not isIPv4(node.ip): # is a IP address?
node = Node(ip=socket.gethostbyname(node.ip),
port=node.port,
type=node.type,
guid=node.guid)
yield self.net.send(Message(name='Discover:Request'),
node=node)
msg = yield self.net.get(
lambda x: x.name == 'Discover:Response' and not x.
multicast,
timeout=timeout)
if msg:
added = False
for node in msg.neighbors:
if node.hostport == msg.remote.hostport: # whether msg.remote exists in msg.neighbors, which means remote is a server and we are already connected.
if _debug: print 'received neighbor', repr(node)
self.neighbors.insert(
0,
node) # put this as most preferred neighbor.
added = True
else:
if _debug: print 'received candidate', repr(node)
candidates.append(
node) # put this as the next candidate
if added:
yield self.net.put(
Message(name='Discover:Indication',
node=self.node,
neighbors=self.neighbors)
) # indicate change in client.
else:
if _debug: print 'bootstrap did not receive response.'
elif not self.server and self.neighbors: # perform neighbor refresh
yield dht.randomsleep(timeout)
result = yield self.net.send(Message(name='Ping:Request'),
node=self.neighbors[0],
timeout=timeout)
if not result: # no response received, remove the neighbor
del self.neighbors[0]
yield self.net.put(
Message(name='Discover:Indication',
node=self.node,
neighbors=self.neighbors)
) # indicate change in client.
elif not self.server and not self.neighbors and not candidates:
candidates = self.candidates[:]
yield dht.randomsleep(timeout)
else: # just wait before trying again.
yield dht.randomsleep(interval)
