当C++遇到IOS应用开发---LRUCache缓存(4)

            _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));