196 lines
5.9 KiB
Python
196 lines
5.9 KiB
Python
# Time between successful PoW solutions
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POW_SOLUTION_TIME = 6
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# Time for a block to traverse the network
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TRANSIT_TIME = 12
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# Max uncle depth
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UNCLE_DEPTH = 4
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# Uncle block reward (normal block reward = 1)
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UNCLE_REWARD_COEFF = 29/32.
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# Reward for including uncles
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NEPHEW_REWARD_COEFF = 1/32.
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# Rounds to test
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ROUNDS = 1000000
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import random
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all_miners = {}
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class Miner():
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def __init__(self, p, backward=0):
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# Miner hashpower
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self.hashpower = p
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# Miner mines a few blocks behind the head?
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self.backward = backward
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self.id = random.randrange(10000000)
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# Set up a few genesis blocks (since the algo is grandpa-dependent,
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# we need two genesis blocks plus some genesis uncles)
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self.blocks = {}
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self.children = {}
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for i in range(UNCLE_DEPTH + 2):
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self.blocks[i] = \
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{"parent": i-1, "uncles": {}, "miner": -1, "height": i,
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"score": i, "id": i}
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self.children[i-1] = {i: True}
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# ID of "latest block"
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self.head = UNCLE_DEPTH + 1
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# Hear about a block
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def recv(self, block):
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# Add the block to the set if it's valid
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addme = True
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if block["id"] in self.blocks:
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addme = False
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if block["parent"] not in self.blocks:
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addme = False
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if addme:
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self.blocks[block["id"]] = block
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if block["parent"] not in self.children:
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self.children[block["parent"]] = {}
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if block["id"] not in self.children[block["parent"]]:
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self.children[block["parent"]][block["id"]] = block["id"]
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if block["score"] > self.blocks[self.head]["score"]:
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self.head = block["id"]
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# Mine a block
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def mine(self):
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HEAD = self.blocks[self.head]
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for i in range(self.backward):
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HEAD = self.blocks[HEAD["parent"]]
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H = HEAD
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h = self.blocks[self.blocks[self.head]["parent"]]
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# Select the uncles. The valid set of uncles for a block consists
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# of the children of the 2nd to N+1th order grandparents minus
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# the parent and said grandparents themselves and blocks that were
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# uncles of those previous blocks
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u = {}
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notu = {}
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for i in range(UNCLE_DEPTH - self.backward):
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for c in self.children.get(h["id"], {}):
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u[c] = True
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notu[H["id"]] = True
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for c in H["uncles"]:
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notu[c] = True
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H = h
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h = self.blocks[h["parent"]]
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for i in notu:
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if i in u:
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del u[i]
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block = {"parent": self.head, "uncles": u, "miner": self.id,
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"height": HEAD["height"] + 1, "score": HEAD["score"]+1+len(u),
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"id": random.randrange(1000000000000)}
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self.recv(block)
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global all_miners
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all_miners[block["id"]] = block
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return block
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# If b1 is the n-th degree grandchild and b2 is the m-th degree grandchild
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# of nearest common ancestor C, returns min(m, n)
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def cousin_degree(miner, b1, b2):
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while miner.blocks[b1]["height"] > miner.blocks[b2]["height"]:
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b1 = miner.blocks[b1]["parent"]
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while miner.blocks[b2]["height"] > miner.blocks[b1]["height"]:
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b2 = miner.blocks[b2]["parent"]
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t = 0
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while b1 != b2:
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b1 = miner.blocks[b1]["parent"]
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b2 = miner.blocks[b2]["parent"]
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t += 1
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return t
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# Set hashpower percentages and strategies
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# Strategy = how many blocks behind head you mine
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profiles = [
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# (hashpower, strategy, count)
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(1, 0, 20),
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(1, -1, 4), # cheaters, mine 1/2/4 blocks back to reduce
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(1, -2, 3), # chance of being in a two-block fork
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(1, -4, 3),
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(5, 4, 1),
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(10, 1, 1),
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(15, 1, 1),
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(25, 1, 1),
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]
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total_pct = 0
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miners = []
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for p, b, c in profiles:
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for i in range(c):
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miners.append(Miner(p, b))
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total_pct += p
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miner_dict = {}
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for m in miners:
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miner_dict[m.id] = m
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listen_queue = []
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for t in range(ROUNDS):
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if t % 5000 == 0:
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print t
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for m in miners:
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R = random.randrange(POW_SOLUTION_TIME * total_pct)
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if R < m.hashpower and t < ROUNDS - TRANSIT_TIME * 3:
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b = m.mine()
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listen_queue.append([t + TRANSIT_TIME, b])
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while len(listen_queue) and listen_queue[0][0] <= t:
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t, b = listen_queue.pop(0)
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for m in miners:
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m.recv(b)
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h = miners[0].blocks[miners[0].head]
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profit = {}
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total_blocks_in_chain = 0
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length_of_chain = 0
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ZORO = {}
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print "### PRINTING BLOCKCHAIN ###"
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while h["id"] > UNCLE_DEPTH + 2:
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# print h["id"], h["miner"], h["height"], h["score"]
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# print "Uncles: ", list(h["uncles"])
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total_blocks_in_chain += 1 + len(h["uncles"])
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ZORO[h["id"]] = True
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length_of_chain += 1
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profit[h["miner"]] = profit.get(h["miner"], 0) + \
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1 + NEPHEW_REWARD_COEFF * len(h["uncles"])
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for u in h["uncles"]:
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ZORO[u] = True
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u2 = miners[0].blocks[u]
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profit[u2["miner"]] = profit.get(u2["miner"], 0) + UNCLE_REWARD_COEFF
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h = miners[0].blocks[h["parent"]]
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print "### PRINTING HEADS ###"
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for m in miners:
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print m.head
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print "### PRINTING PROFITS ###"
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for p in profit:
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print miner_dict.get(p, Miner(0)).hashpower, profit.get(p, 0)
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print "### PRINTING RESULTS ###"
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groupings = {}
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counts = {}
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for p in profit:
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m = miner_dict.get(p, None)
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if m:
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h = str(m.hashpower)+','+str(m.backward)
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counts[h] = counts.get(h, 0) + 1
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groupings[h] = groupings.get(h, 0) + profit[p]
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for c in counts:
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print c, groupings[c] / counts[c] / (groupings['1,0'] / counts['1,0'])
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print " "
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print "Total blocks produced: ", len(all_miners) - UNCLE_DEPTH
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print "Total blocks in chain: ", total_blocks_in_chain
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print "Efficiency: ", \
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total_blocks_in_chain * 1.0 / (len(all_miners) - UNCLE_DEPTH)
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print "Average uncles: ", total_blocks_in_chain * 1.0 / length_of_chain - 1
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print "Length of chain: ", length_of_chain
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print "Block time: ", ROUNDS * 1.0 / length_of_chain
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