class Consensus:
def __init__(self):
self.state = StateMachine()
self.blockchain = Blockchain()
self.transaction_pool = []
self.executed_transactions = []
self.nodes = []
self.lock = Lock()
def set_port(self, port):
ports = [port] #5000, 5001, 5002]
for p in ports:
self.nodes.append(f'127.0.0.1:{p}')
self.me = f'127.0.0.1:{port}'
neighbours = list(self.nodes)
neighbours.remove(self.me)
self.network = Network(self.me, neighbours)
def new_transaction(self, transaction):
self.lock.acquire()
# drive consensus over the transaction
transaction.set_registrer(self.me)
self.add_transaction(transaction)
self.lock.release()
return True
def report_transaction(self, transaction):
self.lock.acquire()
self.add_transaction(transaction)
self.lock.release()
def add_transaction(self, transaction):
if transaction not in self.executed_transactions and transaction not in self.transaction_pool:
self.transaction_pool.append(transaction)
self.network.broadcast_transaction(transaction)
if self.my_turn():
self.sign()
def my_turn(self):
last_signer = self.blockchain.last_signer()
last_index = self.nodes.index(last_signer) if last_signer else -1
next = 0 if last_index + 1 == len(self.nodes) else last_index + 1
return self.nodes[next] == self.me
def execute_block(self, block):
for transaction in block.transactions:
self.state.execute_transaction(transaction)
def sign(self):
block = Block(self.transaction_pool, self.me,
self.blockchain.last_hash())
self.blockchain.add(block)
self.transaction_pool = []
self.network.broadcast_block(block)
self.execute_block(block)
def report_block(self, transactions, signer, previous):
self.lock.acquire()
if self.blockchain.last_hash() == previous:
block = Block(transactions, signer, previous)
self.blockchain.add(block)
for transaction in transactions:
if transaction in self.transaction_pool:
self.transaction_pool.remove(transaction)
self.executed_transactions.append(transaction)
self.network.broadcast_block(block)
self.execute_block(block)
self.lock.release()
