11 #ifndef _LRUCACHE_HPP_INCLUDED_ 12 #define _LRUCACHE_HPP_INCLUDED_ 14 #include <unordered_map> 21 template<
typename key_t,
typename value_t>
31 void put(
const key_t& key,
const value_t& value) {
32 auto it = _cache_items_map.find(key);
34 if (it != _cache_items_map.end()) {
35 _cache_items_list.erase(it->second);
36 _cache_items_map.erase(it);
38 _cache_items_map[key] = _cache_items_list.begin();
40 if (_cache_items_map.size() > _max_size) {
41 auto last = _cache_items_list.end();
43 _cache_items_map.erase(last->first);
44 _cache_items_list.pop_back();
48 const value_t&
get(
const key_t& key) {
49 auto it = _cache_items_map.find(key);
50 if (it == _cache_items_map.end()) {
52 throw std::range_error(
"There is no such key in cache");
54 _cache_items_list.splice(_cache_items_list.begin(), _cache_items_list, it->second);
55 return it->second->second;
59 bool exists(
const key_t& key)
const {
60 return _cache_items_map.find(key) != _cache_items_map.end();
64 return _cache_items_map.size();
68 std::list<key_value_pair_t> _cache_items_list;
69 std::unordered_map<key_t, list_iterator_t> _cache_items_map;
std::list< key_value_pair_t >::iterator list_iterator_t
Definition: LRUCache.h:25
Definition: LRUCache.h:22
bool exists(const key_t &key) const
Definition: LRUCache.h:59
std::pair< key_t, value_t > key_value_pair_t
Definition: LRUCache.h:24
size_t size() const
Definition: LRUCache.h:63
lru_cache(size_t max_size)
Definition: LRUCache.h:27
void put(const key_t &key, const value_t &value)
Definition: LRUCache.h:31
Definition: LRUCache.h:19