def reduction(self, hblock,t_step):
self.votes_heard = []
self.committeeVote(3, t_step, str(hblock))
yield self.env.timeout(L_step)
# self.log ("%d: %d heard %d votes\n"%(self.env.now, self.id, len(self.votes_heard)))
# Count received votes
hblock1 = self.countVotes(3, T_step, t_step)
self.log("%d: got max votes for %s\n"%(self.env.now, hblock1))
eblock = Block(self.block_pointer.hash(),'Empty',self.block_pointer)
ehash = utils.hashBlock(str(eblock))
self.votes_heard = []
if hblock1 == None :
self.committeeVote(4, t_step,str(ehash))
else :
self.committeeVote(4, t_step,str(hblock1))
yield self.env.timeout(L_step)
hblock2 = self.countVotes(4, T_step, t_step)
self.votes_heard = []
if hblock2 == None :
self.log('%d: Result of Reduction is Empty Hash\n'%(self.env.now))
return ehash
else :
self.log('%d: Result of Reduction is %s\n'%(self.env.now,hblock2))
return hblock2
def commonCoin(self, step, t):
minhash = 2**256
for m in self.votes_heard:
votes, value, sorthash = self.processMsg(t, m)
for j in range(1, votes):
h = int(utils.hashBlock(str(sorthash) + str(j)), base=16)
if h < minhash :
minhash = h
self.log('Result of Common Coin : %s\n'%(str(minhash % 2)))
return minhash % 2
def byzagreement(self,round,block,t_step):
hblock = yield from self.reduction(utils.hashBlock(str(block)),t_step)
self.log('%d: Result of Reduction is %s, %d\n'%(self.env.now,str(hblock),t_step))
hblock1 = yield from self.binarybyzagreement(round,hblock,t_step)
yield self.env.timeout(L_step)
r = self.countVotes('FINAL',T_final,t_final)
if hblock1 == r :
self.log('%d: Final consensus is achieved with block %s\n'%(self.env.now,str(block)))
return 'FINAL',block
else :
self.log('%d: Tentative consensus is achieved with block %s\n'%(self.env.now,str(block)))
return 'TENTATIVE',block
def binarybyzagreement(self,round,block_hash,t_step):
step = 3
r = block_hash
eblock = Block(self.block_pointer.hash(),'Empty',self.block_pointer)
empty_hash = utils.hashBlock(str(eblock))
while step < MAX_STEPS :
self.committeeVote(step, t_step, r)
yield self.env.timeout(L_step)
r = self.countVotes(step,T_step,t_step)
if r == None :
r = block_hash
elif r != empty_hash :
for s in range(step+1,step+4) :
self.committeeVote(s, t_step, r)
if step == 3 :
self.committeeVote("FINAL", t_final, r)
return r
step += 1
self.committeeVote(step, t_step, r)
yield self.env.timeout(L_step)
r = self.countVotes(step,T_step,t_step)
if r == None :
r = block_hash
elif r == empty_hash :
for s in range(step+1,step+4) :
self.committeeVote(s, t_step, r)
return r
step += 1
self.committeeVote(step, t_step, r)
yield self.env.timeout(L_step)
r = self.countVotes(step,T_step,t_step)
if r == None:
if self.commonCoin(step, t_step) == 0:
r = block_hash
else:
r = empty_hash
step += 1
self.hangForever()
def processMsg(self, t, message):
if message.payload.prev_block_hash != utils.hashBlock(str(self.block_pointer)):
return 0, None, None
votes = utils.verifySortition(message.pub_key, message.payload.vrf_hash, message.payload.vrf_proof, message.payload.prev_block_hash, message.payload.round, message.payload.step, t, "committee", ctx['weight'][str(message.pub_key)], ctx['W'])
return votes, message.payload.curr_block_hash, message.payload.vrf_hash
def hash(self):
return utils.hashBlock(str(self))