当C++遇到IOS应用开发---LRUCache缓存(4)

来源：未知责任编辑：责任编辑发表时间:2014-01-20 07:51　点击:次

            _lru_list->insert(make_pair(hash_value.access_, key));
            (*_hash_table)[key] = hash_value;
        }
        else {
            _lru_list->insert(make_pair(hash_value.access_, key));

            if ( _hash_table->size() > DEF_CAPACITY )
            {
                // get the least recently used key
                map<virtual_time, HashKey>::iterator iter = _lru_list->begin();
                _hash_table->erase( iter->second );
                // remove last key from list
                _lru_list->erase(iter);
            }
        }
        return 0;
    }

    HashValue* get( const HashKey& key )
    {
        map<HashKey, HashValue>::iterator iter = _hash_table->find(key);
        if ( iter != _hash_table->end() )
        {
            virtual_time old_access = iter->second.access_;
            iter->second.access_ = get_virtual_time();
            //调整当前key在LRU列表中的位置
            map<virtual_time, HashKey>::iterator it = _lru_list->find(old_access);
            if(it != _lru_list->end()) {
                _lru_list->erase(it);
            }
            _lru_list->insert(make_pair(iter->second.access_, key));