用pbft存储数据Python代码
时间: 2024-05-18 13:09:57 浏览: 149
PBFT(Practical Byzantine Fault Tolerance)是一种拜占庭容错算法,常用于分布式系统中保证数据的一致性。它在分布式系统中能够容忍最多 f 个拜占庭节点,而且需要至少 3f + 1 个节点才能进行工作。下面是一个使用 PBFT 存储数据的 Python 代码示例:
```
from hashlib import sha256
class PBFTNode:
def __init__(self, id):
self.id = id
self.current_view = 0
self.sequence_num = 0
self.replicas = [self]
self.messages = {}
self.request_queue = []
self.committed = {}
self.current_state = {}
def add_replica(self, replica):
if replica not in self.replicas:
self.replicas.append(replica)
def request(self, data):
request_id = sha256(str(data).encode()).hexdigest()
self.request_queue.append(request_id)
self.broadcast_request(request_id, data)
def broadcast_request(self, request_id, data):
for replica in self.replicas:
replica.messages[request_id] = (self.id, data)
def prepare(self, request_id):
if request_id not in self.messages:
return False
sender_id, data = self.messages[request_id]
message_digest = sha256(str((sender_id, request_id)).encode()).hexdigest()
for replica in self.replicas:
if replica.id != self.id:
if message_digest not in replica.messages or replica.messages[message_digest] != (sender_id, data):
return False
return True
def commit(self, request_id):
if request_id not in self.messages:
return False
sender_id, data = self.messages[request_id]
message_digest = sha256(str((sender_id, request_id)).encode()).hexdigest()
for replica in self.replicas:
if replica.id != self.id:
if message_digest not in replica.messages or replica.messages[message_digest] != (sender_id, data):
return False
if request_id not in self.committed:
self.committed[request_id] = True
self.current_state[request_id] = data
return True
return False
def run(self):
while True:
while len(self.request_queue) > 0:
request_id = self.request_queue.pop(0)
if self.prepare(request_id):
self.broadcast_prepare(request_id)
prepare_count = 1
for replica in self.replicas:
if replica.id != self.id and replica.prepare(request_id):
prepare_count += 1
if prepare_count >= 2 * f + 1:
break
if prepare_count >= 2 * f + 1:
self.broadcast_commit(request_id)
commit_count = 1
for replica in self.replicas:
if replica.id != self.id and replica.commit(request_id):
commit_count += 1
if commit_count >= 2 * f + 1:
break
def broadcast_prepare(self, request_id):
for replica in self.replicas:
replica.messages[request_id] = (self.id, "PREPARE")
def broadcast_commit(self, request_id):
for replica in self.replicas:
replica.messages[request_id] = (self.id, "COMMIT")
```
这个示例代码定义了一个名为 `PBFTNode` 的类来实现 PBFT 算法。该类包含了节点的 ID、当前视图号、序列号、副本列表、消息列表、请求队列、已提交数据列表和当前状态。其中,`add_replica` 方法用于添加副本节点;`request` 方法用于将数据添加到请求队列中并广播请求;`broadcast_request` 方法用于将请求广播给所有副本节点;`prepare` 方法和 `commit` 方法分别用于检查是否准备就绪和提交请求;`broadcast_prepare` 方法和 `broadcast_commit` 方法分别用于将准备就绪和提交请求广播给所有副本节点。
在这个示例代码中,使用 SHA-256 哈希函数来生成消息摘要,并使用字符串格式存储数据。当然,你可以根据自己的需要进行修改。另外,在这个示例代码中,我使用了无限循环来模拟节点的运行。你可以根据自己的需要进行修改。
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