54：全球1000+节点P2P网络：Chord算法与分布式哈希表

class ChordNode:
    def __init__(self, node_id, m=160):
        self.node_id = node_id
        self.m = m
        self.finger_table = [None] * m  #  Finger表
        self.predecessor = None
        self.successor = None
    
    def find_successor(self, key):
        """查找key对应的后继节点"""
        if key == self.node_id:
            return self
        if self._is_between(key, self.node_id, self.successor.node_id):
            return self.successor
        else:
            # 查找离key最近的前驱节点
            node = self._closest_preceding_node(key)
            return node.find_successor(key)
    
    def _closest_preceding_node(self, key):
        """查找离key最近的前驱节点"""
        for i in range(self.m-1, -1, -1):
            if self.finger_table[i] and self._is_between(self.finger_table[i].node_id, self.node_id, key):
                return self.finger_table[i]
        return self
    
    def _is_between(self, x, a, b):
        """判断x是否在(a, b)区间内"""
        if a < b:
            return a < x < b
        else:
            return x > a or x < b

class DHT:
    def __init__(self, chord_node):
        self.chord_node = chord_node
        self.data_store = {}
    
    def put(self, key, value):
        """存储键值对"""
        # 计算key的哈希值
        key_hash = self._hash(key)
        # 查找负责该key的节点
        node = self.chord_node.find_successor(key_hash)
        # 存储数据
        node.dht.data_store[key] = value
        return True
    
    def get(self, key):
        """获取键值对"""
        # 计算key的哈希值
        key_hash = self._hash(key)
        # 查找负责该key的节点
        node = self.chord_node.find_successor(key_hash)
        # 获取数据
        return node.dht.data_store.get(key, None)
    
    def _hash(self, key):
        """哈希函数"""
        import hashlib
        return int(hashlib.sha1(key.encode()).hexdigest(), 16) % (2 ** self.chord_node.m)

class EncryptedChordNode(ChordNode):
    def __init__(self, node_id, private_key, public_keys):
        super().__init__(node_id)
        self.private_key = private_key
        self.public_keys = public_keys  # 存储其他节点的公钥
    
    def route_query(self, key, data):
        """加密路由查询"""
        # 找到目标节点
        target_node = self.find_successor(key)
        # 使用目标节点的公钥加密数据
        encrypted_data = self._encrypt(data, self.public_keys[target_node.node_id])
        # 转发加密数据
        return self._forward_to_node(target_node, encrypted_data)
    
    def _encrypt(self, data, public_key):
        """使用公钥加密数据"""
        # 实现加密逻辑
        pass
    
    def _forward_to_node(self, node, data):
        """转发数据到指定节点"""
        # 实现转发逻辑
        pass