#pragma once #include #include #include #include #include namespace swoole { /** * This cache isn't thread safe */ class LRUCache { private: typedef std::pair> cache_node_t; typedef std::list> cache_list_t; std::unordered_map cache_map; cache_list_t cache_list; size_t cache_capacity; public: explicit LRUCache(size_t capacity) { cache_capacity = capacity; } inline std::shared_ptr get(const std::string &key) { auto iter = cache_map.find(key); if (iter == cache_map.end()) { return nullptr; } if (iter->second->second.first < time(nullptr) && iter->second->second.first > 0) { return nullptr; } cache_list.splice(cache_list.begin(), cache_list, iter->second); return iter->second->second.second; // iter -> list::iter -> cache_node_t -> value } inline void set(const std::string &key, const std::shared_ptr &val, time_t expire = 0) { time_t expire_time; if (expire <= 0) { expire_time = 0; } else { expire_time = time(nullptr) + expire; } auto iter = cache_map.find(key); if (iter != cache_map.end()) { iter->second->second.first = expire_time; iter->second->second.second = val; cache_list.splice(cache_list.begin(), cache_list, iter->second); return; } size_t size = cache_list.size(); if (size == cache_capacity && size > 0) { auto del = cache_list.back(); cache_map.erase(del.first); cache_list.pop_back(); } cache_list.emplace_front(key, cache_node_t{expire_time, val}); cache_map[key] = cache_list.begin(); } inline void del(const std::string &key) { auto iter = cache_map.find(key); if (iter == cache_map.end()) { return; } cache_list.erase(iter->second); cache_map.erase(iter); } inline void clear() { cache_list.clear(); cache_map.clear(); } }; }