# Time between successful PoW solutions POW_SOLUTION_TIME = 60 # Time for a block to traverse the network TRANSIT_TIME = 12 # Max uncle depth UNCLE_DEPTH = 0 # Uncle block reward (normal block reward = 1) UNCLE_REWARD_COEFF = 7/8. # Reward for including uncles NEPHEW_REWARD_COEFF = 1/16. # Rounds to test ROUNDS = 1000000 import random all_miners = {} class Miner(): def __init__(self, p): self.hashpower = p self.id = random.randrange(10000000) # Set up a few genesis blocks (since the algo is grandpa-dependent, # we need two genesis blocks plus some genesis uncles) self.blocks = {} self.children = {} for i in range(UNCLE_DEPTH + 2): self.blocks[i] = \ {"parent": i-1, "uncles": {}, "miner": -1, "height": i, "score": i, "id": i} self.children[i-1] = {i: True} # ID of "latest block" self.head = UNCLE_DEPTH + 1 # Hear about a block def recv(self, block): # Add the block to the set if it's valid addme = True if block["id"] in self.blocks: addme = False if block["parent"] not in self.blocks: addme = False if addme: self.blocks[block["id"]] = block if block["parent"] not in self.children: self.children[block["parent"]] = {} if block["id"] not in self.children[block["parent"]]: self.children[block["parent"]][block["id"]] = block["id"] if block["score"] > self.blocks[self.head]["score"]: self.head = block["id"] # Mine a block def mine(self): HEAD = self.blocks[self.head] H = HEAD h = self.blocks[self.blocks[self.head]["parent"]] # Select the uncles. The valid set of uncles for a block consists # of the children of the 2nd to N+1th order grandparents minus # the parent and said grandparents themselves and blocks that were # uncles of those previous blocks u = {} notu = {} for i in range(UNCLE_DEPTH): for c in self.children.get(h["id"], {}): u[c] = True notu[H["id"]] = True for c in H["uncles"]: notu[c] = True H = h h = self.blocks[h["parent"]] for i in notu: if i in u: del u[i] block = {"parent": self.head, "uncles": u, "miner": self.id, "height": HEAD["height"] + 1, "score": HEAD["score"]+1+len(u), "id": random.randrange(1000000000000)} self.recv(block) global all_miners all_miners[block["id"]] = block return block # If b1 is the n-th degree grandchild and b2 is the m-th degree grandchild # of nearest common ancestor C, returns min(m, n) def cousin_degree(miner, b1, b2): while miner.blocks[b1]["height"] > miner.blocks[b2]["height"]: b1 = miner.blocks[b1]["parent"] while miner.blocks[b2]["height"] > miner.blocks[b1]["height"]: b2 = miner.blocks[b2]["parent"] t = 0 while b1 != b2: b1 = miner.blocks[b1]["parent"] b2 = miner.blocks[b2]["parent"] t += 1 return t # Set hashpower percentages here percentages = [1]*25 + [5, 5, 5, 5, 5, 10, 15, 25] miners = [] for p in percentages: miners.append(Miner(p)) miner_dict = {} for m in miners: miner_dict[m.id] = m listen_queue = [] for t in range(ROUNDS): if t % 5000 == 0: print t for m in miners: R = random.randrange(POW_SOLUTION_TIME * sum(percentages)) if R < m.hashpower and t < ROUNDS - TRANSIT_TIME * 3: b = m.mine() listen_queue.append([t + TRANSIT_TIME, b]) while len(listen_queue) and listen_queue[0][0] <= t: t, b = listen_queue.pop(0) for m in miners: m.recv(b) h = miners[0].blocks[miners[0].head] profit = {} total_blocks_in_chain = 0 length_of_chain = 0 ZORO = {} print "### PRINTING BLOCKCHAIN ###" while h["id"] > UNCLE_DEPTH + 2: # print h["id"], h["miner"], h["height"], h["score"] # print "Uncles: ", list(h["uncles"]) total_blocks_in_chain += 1 + len(h["uncles"]) ZORO[h["id"]] = True length_of_chain += 1 profit[h["miner"]] = profit.get(h["miner"], 0) + \ 1 + NEPHEW_REWARD_COEFF * len(h["uncles"]) for u in h["uncles"]: ZORO[u] = True u2 = miners[0].blocks[u] profit[u2["miner"]] = profit.get(u2["miner"], 0) + UNCLE_REWARD_COEFF h = miners[0].blocks[h["parent"]] print "### PRINTING HEADS ###" for m in miners: print m.head print "### PRINTING PROFITS ###" for p in profit: print miner_dict[p].hashpower, profit[p] print "### PRINTING RESULTS ###" groupings = {} counts = {} for p in profit: h = miner_dict[p].hashpower counts[h] = counts.get(h, 0) + 1 groupings[h] = groupings.get(h, 0) + profit[p] for c in counts: print c, groupings[c] / counts[c] / (groupings[1] / counts[1]) print " " print "Total blocks produced: ", len(all_miners) - UNCLE_DEPTH print "Total blocks in chain: ", total_blocks_in_chain print "Efficiency: ", \ total_blocks_in_chain * 1.0 / (len(all_miners) - UNCLE_DEPTH) print "Average uncles: ", total_blocks_in_chain * 1.0 / length_of_chain - 1 print "Length of chain: ", length_of_chain print "Block time: ", ROUNDS * 1.0 / length_of_chain