Method get

cpp/src/gandiva/lru_cache.h:72–100

  }

  std::optional<value_type> get(const key_type& key) {
    // lookup value in the cache
    typename map_type::iterator value_for_key = map_.find(key);
    if (value_for_key == map_.end()) {
      // value not in cache
      return std::nullopt;
    }

    // return the value, but first update its place in the most
    // recently used list
    typename list_type::iterator position_in_lru_list = value_for_key->second.second;
    if (position_in_lru_list != lru_list_.begin()) {
      // move item to the front of the most recently used list
      lru_list_.erase(position_in_lru_list);
      lru_list_.push_front(key);

      // update iterator in map
      position_in_lru_list = lru_list_.begin();
      const value_type& value = value_for_key->second.first;
      map_[key] = std::make_pair(value, position_in_lru_list);

      // return the value
      return value;
    } else {
      // the item is already at the front of the most recently
      // used list so just return it
      return value_for_key->second.first;
    }
  }

  void clear() {
    map_.clear();