from ethereum.casper_utils import RandaoManager, get_skips_and_block_making_time, \ generate_validation_code, call_casper, sign_block, check_skips, get_timestamp, \ get_casper_ct, get_dunkle_candidates, \ make_withdrawal_signature from ethereum.utils import sha3, hash32, privtoaddr, ecsign, zpad, encode_int32, \ big_endian_to_int from ethereum.transaction_queue import TransactionQueue from ethereum.block_creation import make_head_candidate from ethereum.block import Block from ethereum.transactions import Transaction from ethereum.chain import Chain import networksim import rlp import random CHECK_FOR_UNCLES_BACK = 8 global_block_counter = 0 casper_ct = get_casper_ct() class ChildRequest(rlp.Serializable): fields = [ ('prevhash', hash32) ] def __init__(self, prevhash): self.prevhash = prevhash @property def hash(self): return sha3(self.prevhash + '::salt:jhfqou213nry138o2r124124') ids = [] class Validator(): def __init__(self, genesis, key, network, env, time_offset=5): # Create a chain object self.chain = Chain(genesis, env=env) # Create a transaction queue self.txqueue = TransactionQueue() # Use the validator's time as the chain's time self.chain.time = lambda: self.get_timestamp() # My private key self.key = key # My address self.address = privtoaddr(key) # My randao self.randao = RandaoManager(sha3(self.key)) # Pointer to the test p2p network self.network = network # Record of objects already received and processed self.received_objects = {} # The minimum eligible timestamp given a particular number of skips self.next_skip_count = 0 self.next_skip_timestamp = 0 # Is this validator active? self.active = False # Code that verifies signatures from this validator self.validation_code = generate_validation_code(privtoaddr(key)) # Validation code hash self.vchash = sha3(self.validation_code) # Parents that this validator has already built a block on self.used_parents = {} # This validator's clock offset (for testing purposes) self.time_offset = random.randrange(time_offset) - (time_offset // 2) # Determine the epoch length self.epoch_length = self.call_casper('getEpochLength') # My minimum gas price self.mingasprice = 20 * 10**9 # Give this validator a unique ID self.id = len(ids) ids.append(self.id) self.update_activity_status() self.cached_head = self.chain.head_hash def call_casper(self, fun, args=[]): return call_casper(self.chain.state, fun, args) def update_activity_status(self): start_epoch = self.call_casper('getStartEpoch', [self.vchash]) now_epoch = self.call_casper('getEpoch') end_epoch = self.call_casper('getEndEpoch', [self.vchash]) if start_epoch <= now_epoch < end_epoch: self.active = True self.next_skip_count = 0 self.next_skip_timestamp = get_timestamp(self.chain, self.next_skip_count) print 'In current validator set' else: self.active = False def get_timestamp(self): return int(self.network.time * 0.01) + self.time_offset def on_receive(self, obj): if isinstance(obj, list): for _obj in obj: self.on_receive(_obj) return if obj.hash in self.received_objects: return if isinstance(obj, Block): print 'Receiving block', obj assert obj.hash not in self.chain block_success = self.chain.add_block(obj) self.network.broadcast(self, obj) self.network.broadcast(self, ChildRequest(obj.header.hash)) self.update_head() elif isinstance(obj, Transaction): print 'Receiving transaction', obj if obj.gasprice >= self.mingasprice: self.txqueue.add_transaction(obj) print 'Added transaction, txqueue size %d' % len(self.txqueue.txs) self.network.broadcast(self, obj) else: print 'Gasprice too low' self.received_objects[obj.hash] = True for x in self.chain.get_chain(): assert x.hash in self.received_objects def tick(self): # Try to create a block # Conditions: # (i) you are an active validator, # (ii) you have not yet made a block with this parent if self.active and self.chain.head_hash not in self.used_parents: t = self.get_timestamp() # Is it early enough to create the block? if t >= self.next_skip_timestamp and (not self.chain.head or t > self.chain.head.header.timestamp): # Wrong validator; in this case, just wait for the next skip count if not check_skips(self.chain, self.vchash, self.next_skip_count): self.next_skip_count += 1 self.next_skip_timestamp = get_timestamp(self.chain, self.next_skip_count) # print 'Incrementing proposed timestamp for block %d to %d' % \ # (self.chain.head.header.number + 1 if self.chain.head else 0, self.next_skip_timestamp) return self.used_parents[self.chain.head_hash] = True # Simulated 15% chance of validator failure to make a block if random.random() > 0.999: print 'Simulating validator failure, block %d not created' % (self.chain.head.header.number + 1 if self.chain.head else 0) return # Make the block s1 = self.chain.state.trie.root_hash pre_dunkle_count = self.call_casper('getTotalDunklesIncluded') dunkle_txs = get_dunkle_candidates(self.chain, self.chain.state) blk = make_head_candidate(self.chain, self.txqueue) randao = self.randao.get_parent(self.call_casper('getRandao', [self.vchash])) blk = sign_block(blk, self.key, randao, self.vchash, self.next_skip_count) # Make sure it's valid global global_block_counter global_block_counter += 1 for dtx in dunkle_txs: assert dtx in blk.transactions, (dtx, blk.transactions) print 'made block with timestamp %d and %d dunkles' % (blk.timestamp, len(dunkle_txs)) s2 = self.chain.state.trie.root_hash assert s1 == s2 assert blk.timestamp >= self.next_skip_timestamp assert self.chain.add_block(blk) self.update_head() post_dunkle_count = self.call_casper('getTotalDunklesIncluded') assert post_dunkle_count - pre_dunkle_count == len(dunkle_txs) self.received_objects[blk.hash] = True print 'Validator %d making block %d (%s)' % (self.id, blk.header.number, blk.header.hash[:8].encode('hex')) self.network.broadcast(self, blk) # Sometimes we received blocks too early or out of order; # run an occasional loop that processes these if random.random() < 0.02: self.chain.process_time_queue() self.chain.process_parent_queue() self.update_head() def update_head(self): if self.cached_head == self.chain.head_hash: return self.cached_head = self.chain.head_hash if self.chain.state.block_number % self.epoch_length == 0: self.update_activity_status() if self.active: self.next_skip_count = 0 self.next_skip_timestamp = get_timestamp(self.chain, self.next_skip_count) print 'Head changed: %s, will attempt creating a block at %d' % (self.chain.head_hash.encode('hex'), self.next_skip_timestamp) def withdraw(self, gasprice=20 * 10**9): sigdata = make_withdrawal_signature(self.key) txdata = casper_ct.encode('startWithdrawal', [self.vchash, sigdata]) tx = Transaction(self.chain.state.get_nonce(self.address), gasprice, 650000, self.chain.config['CASPER_ADDR'], 0, txdata).sign(self.key) self.txqueue.add_transaction(tx, force=True) self.network.broadcast(self, tx) print 'Withdrawing!' def deposit(self, gasprice=20 * 10**9): assert value * 10**18 >= self.chain.state.get_balance(self.address) + gasprice * 1000000 tx = Transaction(self.chain.state.get_nonce(self.address) * 10**18, gasprice, 1000000, casper_config['CASPER_ADDR'], value * 10**18, ct.encode('deposit', [self.validation_code, self.randao.get(9999)]))