research-lab/source-code/Spectre/BlockDAG.py
Brandon Goodell 253f70d248 playing
2017-11-05 16:17:34 -07:00

227 lines
11 KiB
Python

from Block import *
#### #### #### #### #### #### #### #### #### #### #### #### #### #### #### ####
class BlockDAG(object):
""" Collection of >=1 block. """
def __init__(self, params=None):
self.genesis = Block()
self.genesis.id = "0"
self.blocks = {self.genesis.id:self.genesis}
self.leaves = {self.genesis.id:self.genesis}
# Blocks from top-down antichain subsets covering >= 1/2 of blockDAG
self.votBlocks = {self.genesis.id:self.genesis}
# Blocks from top-down antichain subsets "non-negl" likely to re-org
self.ordBlocks = {self.genesis.id:self.genesis}
if params is not None:
self.security = params
else:
self.security = 10
self.vote = {}
self.pending = {}
for blockZ in self.votBlocks:
for blockX in self.ordBlocks:
for blockY in self.ordBlocks:
self.vote.update({(blockZ,blockX,blockY):0})
self.pending.update({(blockZ,blockX,blockY):0})
def computeVote(self, dagIn):
(canopy, fullCanopy) = self.pick(dagIn)
for layer in fullCanopy:
for blockZ in layer:
if blockZ not in dagIn.votBlocks:
continue
else:
for blockX in layer:
if blockX not in dagIn.ordBlocks:
continue
else:
for blockY in layer:
if blockY not in dagIn.ordBlocks:
continue
else:
if self.inPast(dagIn,blockY,blockZ) and self.inPast(dagIn,blockX,blockZ):
# then Z votes recursively
if blockZ not in dagIn.seenPasts:
dagIn.seenPasts.update({blockZ:dagIn.getPast(blockZ)})
dagIn.seenVotes.update({blockZ:dagIn.vote(dagIn.seenPasts[blockZ])})
dagIn.vote.update({(blockZ,blockX,blockY):dagIn.seenVotes[blockZ][(blockX,blockY)], (blockZ,blockY,blockX):dagIn.seenVotes[blockZ][(blockY,blockX)], (blockZ,blockX,blockZ):1, (blockZ, blockZ, blockX):-1, (blockZ, blockY, blockZ):1, (blockZ, blockZ, blockY):-1})
elif self.inPast(dagIn, blockY, blockZ) and not self.inPast(dagIn, blockX, blockZ):
dagIn.vote.update({(blockZ,blockX,blockY):-1, (blockZ,blockY,blockX):1, (blockZ,blockX,blockZ):-1, (blockZ,blockZ,blockX):1, (blockZ,blockZ,blockY):-1, (blockZ,blockY,blockZ):1}) # Then Z votes Y < Z < X
elif not self.inPast(dagIn, blockY, blockZ) and self.inPast(dagIn, blockX, blockZ):
dagIn.vote.update({(blockZ,blockX,blockY):1, (blockZ,blockY,blockX):-1, (blockZ,blockX,blockZ):1, (blockZ,blockZ,blockX):-1, (blockZ,blockZ,blockY):1, (blockZ,blockY,blockZ):-1}) # Then Z votes X < Z < Y
else:
if dagIn.pending[(blockZ,blockX,blockY)] > 0:
dagIn.vote.update({(blockZ,blockX,blockY):1, (blockZ,blockY,blockX):-1, (blockZ, blockX, blockZ):-1, (blockZ, blockZ, blockX):1, (blockZ, blockY, blockZ):-1, (blockZ, blockZ, blockY):1})
elif dagIn.pending[(blockZ,blockX,blockY)] < 0:
dagIn.vote.update({(blockZ,blockX,blockY):-1, (blockZ,blockY,blockX):1, (blockZ, blockX, blockZ):-1, (blockZ, blockZ, blockX):1, (blockZ, blockY, blockZ):-1, (blockZ, blockZ, blockY):1})
else:
dagIn.vote.update({(blockZ,blockX,blockY):0, (blockZ,blockY,blockX):0, (blockZ, blockX, blockZ):-1, (blockZ, blockZ, blockX):1, (blockZ, blockY, blockZ):-1, (blockZ, blockZ, blockY):1})
q = deque()
for p in dagIn.blocks[blockZ].parents:
if p in dagIn.votBlocks:
q.append(p)
while(len(q)>0):
nextBlock = q.popleft()
if (nextBlock, blockX, blockY) not in dagIn.pending:
dagIn.pending.update({(nextBlock, blockX,blockY):0})
if (nextBlock, blockY, blockX) not in dagIn.pending:
dagIn.pending.update({(nextBlock, blockY,blockX):0})
if dagIn.vote[(blockZ,blockX,blockY)] > 0:
dagIn.pending[(nextBlock,blockX,blockY)] += 1
dagIn.pending[(nextBlock,blockY,blockX)] -= 1
elif dagIn.vote[(blockZ,blockX,blockY)] < 0:
dagIn.pending[(nextBlock,blockX,blockY)] -= 1
dagIn.pending[(nextBlock,blockY,blockX)] += 1
for p in dagIn.blocks[nextBlock].parents:
if p in dagIn.votBlocks:
q.append(p)
totalVote = {}
for blockX in dagIn.ordBlocks:
for blockY in dagIn.ordBlocks:
if (blockX, blockY) not in totalVote:
totalVote.update({(blockX,blockY):0, (blockY,blockX):0})
for blockZ in dagIn.votBlocks:
if dagIn.vote[(blockZ,blockX,blockY)] > 0:
totalVote[(blockX,blockY)] += 1
elif dagIn.vote[(blockZ,blockX,blockY)] < 0:
totalVote[(blockX,blockY)] -= 1
if totalVote[(blockX,blockY)] > 0:
totalVote[(blockX,blockY)] = 1
elif totalVote[(blockX,blockY)] < 0:
totalVote[(blockX,blockY)] = -1
return totalVote
def pick(self, dagIn):
""" Pick voting blocks and orderable blocks """
(canopy, fullCanopy) = self.antichain(dagIn)
dagIn.votBlocks = {}
dagIn.ordBlocks = {}
idx = 0
count = len(canopy[idx])
for block in canopy[idx]:
dagIn.votBlocks.update({block:dagIn.blocks[block]})
dagIn.ordBlocks.update({blcok:dagIn.blocks[block]})
numVoters = 1 - ((-len(dagIn.blocks))//2)
while(count < numVoters):
idx += 1
count += len(canopy[idx])
for block in canopy[idx]:
dagIn.votBlocks.update({block:dagIn.blocks[block]})
if idx < self.security:
dagIn.ordBlocks.update({block:dagIn.blocks[block]})
return (canopy, fullCanopy)
def makeBlock(self, idIn, parentsIn):
assert idIn not in self.blocks
newBlock = Block()
newBlock.id = idIn
newBlock.addParents(parentsIn)
self.blocks.update({newBlock.id:newBlock})
for parent in parentsIn:
if parent in self.leaves:
del self.leaves[parent]
self.blocks[parent].addChild(newBlock)
self.leaves.update({newBlock.id:newBlock})
def pruneLeaves(self, dagIn):
result = BlockDAG()
result.genesis.id = dagIn.genesis.id
q = deque()
for child in dagIn.genesis.children:
if child not in dagIn.leaves:
q.append(child)
while(len(q)>0):
nextBlock = q.popleft()
result.makeBlock(nextBlock, dagIn.blocks[nextBlock].parents)
for child in dagIn.blocks[nextBlock].children:
if child not in dagIn.leaves:
q.append(child)
return result
def antichain(self, dagIn):
canopy = []
fullCanopy = []
nextDag = dagIn
canopy.append(nextDag.leaves)
fullCanopy.append(nextDag.leaves)
while(len(nextDag.blocks)>1):
nextDag = dagIn.pruneLeaves(dagIn)
canopy.append(nextDag.leaves)
fullCanopy.append(fullCanopy[-1])
for leaf in nextDag.leaves:
fullCanopy[-1].append(leaf)
nextDag = self.pruneLeaves(dagIn)
return (canopy, fullCanopy)
def inPast(self, dagIn, y, x):
""" self.inPast(dag, y,x) if and only if y is in the past of x in dag """
found = False
if y in dagIn.blocks[x].parents:
found = True
else:
q = deque()
for parent in dagIn.blocks[x].parents:
q.append(parent)
while(len(q)>0):
nextBlock = q.popleft()
if y in dagIn.blocks[nextBlock].parents:
found = True
break
else:
for parent in dagIn.blocks[nextBlock].parents:
q.append(parent)
return found
def getPast(self, dagIn, block):
subdag = BlockDAG()
subdag.genesis = dagIn.genesis
q = deque()
for child in dagIn.genesis.children:
if self.inPast(dagIn,child,block):
q.append(child)
while len(q) > 0:
nextBlock = q.popleft()
subdag.makeBlock(dagIn.blocks[nextBlock])
for child in dagIn.blocks[nextBlock].children:
if self.inPast(dagIn,child,block):
q.append(child)
return subdag
class Test_BlockDAG(unittest.TestCase):
def test_BlockDAG(self):
dag = BlockDAG()
self.assertTrue("0" in dag.blocks)
self.assertTrue("0" in dag.leaves)
self.assertTrue(len(dag.blocks)==1)
self.assertTrue(len(dag.leaves)==1)
b0 = dag.genesis
dag.makeBlock("1",{"0":b0})
b1 = dag.blocks["1"]
self.assertTrue("1" in dag.blocks)
self.assertTrue("1" in dag.leaves)
self.assertTrue("0" not in dag.leaves)
self.assertTrue(len(dag.blocks)==2)
self.assertTrue(len(dag.leaves)==1)
self.assertTrue("1" in b0.children)
self.assertTrue("1" in dag.genesis.children)
self.assertTrue("1" in dag.blocks[dag.genesis.id].children)
dag.makeBlock("2", {"0":b0})
b2 = dag.blocks["2"]
dag.makeBlock("3", {"1":b1, "2":b2})
b3 = dag.blocks["3"]
dag.makeBlock("4", {"2":b2})
b4 = dag.blocks["4"]
print(dag.computeVote(dag))
suite = unittest.TestLoader().loadTestsFromTestCase(Test_BlockDAG)
unittest.TextTestRunner(verbosity=1).run(suite)