(二)区块链的共识算法:PoS 及其 例子 代码 实现
时间: 2023-08-06 16:09:39 浏览: 149
PoS(Proof of Stake)是一种区块链的共识算法,它通过锁定一定数量的代币来决定区块的生成权,相比于 PoW(Proof of Work)更加节能且不容易被攻击。下面给出一个简单的 PoS 示例代码实现:
```
import hashlib
import random
class Block:
def __init__(self, index, timestamp, data, previous_hash, validator):
self.index = index
self.timestamp = timestamp
self.data = data
self.previous_hash = previous_hash
self.validator = validator
self.hash = self.calculate_hash()
def calculate_hash(self):
return hashlib.sha256(str(self.index).encode('utf-8') +
str(self.timestamp).encode('utf-8') +
str(self.data).encode('utf-8') +
str(self.previous_hash).encode('utf-8') +
str(self.validator).encode('utf-8')).hexdigest()
class Blockchain:
def __init__(self):
self.chain = [self.create_genesis_block()]
self.nodes = []
def create_genesis_block(self):
return Block(0, '01/01/2020', 'Genesis Block', '0', None)
def add_node(self, node):
self.nodes.append(node)
def get_validator(self):
total_stake = sum([node.stake for node in self.nodes])
winning_num = random.uniform(0, total_stake)
current_num = 0
for node in self.nodes:
current_num += node.stake
if current_num > winning_num:
return node
def add_block(self, data):
previous_block = self.chain[-1]
validator = self.get_validator()
new_block = Block(len(self.chain),
str(datetime.datetime.now()),
data,
previous_block.hash,
validator)
self.chain.append(new_block)
print(f"Block {new_block.index} has been added to the chain by {validator.name}.\n")
class Node:
def __init__(self, name, stake):
self.name = name
self.stake = stake
if __name__ == '__main__':
blockchain = Blockchain()
node1 = Node('Alice', 100)
node2 = Node('Bob', 50)
node3 = Node('Charlie', 150)
blockchain.add_node(node1)
blockchain.add_node(node2)
blockchain.add_node(node3)
blockchain.add_block('Transaction A')
blockchain.add_block('Transaction B')
blockchain.add_block('Transaction C')
```
在上面的代码中,我们定义了一个 Block 类来表示区块,包含索引、时间戳、数据、前一个区块的哈希值和验证者等属性,以及一个 calculate_hash 方法来计算区块的哈希值。同时,我们还定义了一个 Blockchain 类来表示区块链,包含链和参与 PoS 共识的节点列表两个属性,以及 create_genesis_block、add_node、get_validator、add_block 等方法。其中,get_validator 方法用于随机选择一个验证者节点,add_block 方法用于添加新的区块并指定验证者。最后,在主程序中我们创建了三个节点,并添加了三个区块,每个区块的验证者都是随机选择的。
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