chatterino2
Code Issues

optimize chatter list (#2814)

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* optimize chatter list

* changelog

* Fix tests

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>
This commit is contained in:
fourtf
2021-05-24 12:13:59 +02:00
committed by GitHub
parent 7659dc27ae
commit 3fddafb867
19 changed files with 371 additions and 532 deletions
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lib/lrucache/lrucache/lrucache.hpp
+97 -54
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@@ -1,72 +1,115 @@
/*
/*
* File: lrucache.hpp
* Author: Alexander Ponomarev
* Original Author: Alexander Ponomarev
*
* Created on June 20, 2013, 5:09 PM
*/
#ifndef _LRUCACHE_HPP_INCLUDED_
#define _LRUCACHE_HPP_INCLUDED_
#define _LRUCACHE_HPP_INCLUDED_
#include <unordered_map>
#include <list>
#include <cstddef>
#include <list>
#include <stdexcept>
#include <unordered_map>
namespace cache {
template<typename key_t, typename value_t>
class lru_cache {
template <typename key_t, typename value_t>
class lru_cache
{
public:
typedef typename std::pair<key_t, value_t> key_value_pair_t;
typedef typename std::list<key_value_pair_t>::iterator list_iterator_t;
typedef typename std::pair<key_t, value_t> key_value_pair_t;
typedef typename std::list<key_value_pair_t>::iterator list_iterator_t;
lru_cache(size_t max_size)
: _max_size(max_size)
{
}
// copy doesn't make sense since we reference the linked list elements directly
lru_cache(lru_cache<key_t, value_t> &) = delete;
lru_cache<key_t, value_t> &operator=(lru_cache<key_t, value_t> &) = delete;
// move
lru_cache(lru_cache<key_t, value_t> &&other)
: _cache_items_list(std::move(other._cache_items_list))
, _cache_items_map(std::move(other._cache_items_map))
{
other._cache_items_list.clear();
other._cache_items_map.clear();
}
lru_cache<key_t, value_t> &operator=(lru_cache<key_t, value_t> &&other)
{
_cache_items_list = std::move(other._cache_items_list);
_cache_items_map = std::move(other._cache_items_map);
other._cache_items_list.clear();
other._cache_items_map.clear();
return *this;
}
void put(const key_t &key, const value_t &value)
{
auto it = _cache_items_map.find(key);
_cache_items_list.push_front(key_value_pair_t(key, value));
if (it != _cache_items_map.end())
{
_cache_items_list.erase(it->second);
_cache_items_map.erase(it);
}
_cache_items_map[key] = _cache_items_list.begin();
if (_cache_items_map.size() > _max_size)
{
auto last = _cache_items_list.end();
last--;
_cache_items_map.erase(last->first);
_cache_items_list.pop_back();
}
}
const value_t &get(const key_t &key)
{
auto it = _cache_items_map.find(key);
if (it == _cache_items_map.end())
{
throw std::range_error("There is no such key in cache");
}
else
{
_cache_items_list.splice(_cache_items_list.begin(),
_cache_items_list, it->second);
return it->second->second;
}
}
bool exists(const key_t &key) const
{
return _cache_items_map.find(key) != _cache_items_map.end();
}
size_t size() const
{
return _cache_items_map.size();
}
auto begin() const
{
return _cache_items_list.begin();
}
auto end() const
{
return _cache_items_list.end();
}
lru_cache(size_t max_size) :
_max_size(max_size) {
}
void put(const key_t& key, const value_t& value) {
auto it = _cache_items_map.find(key);
_cache_items_list.push_front(key_value_pair_t(key, value));
if (it != _cache_items_map.end()) {
_cache_items_list.erase(it->second);
_cache_items_map.erase(it);
}
_cache_items_map[key] = _cache_items_list.begin();
if (_cache_items_map.size() > _max_size) {
auto last = _cache_items_list.end();
last--;
_cache_items_map.erase(last->first);
_cache_items_list.pop_back();
}
}
const value_t& get(const key_t& key) {
auto it = _cache_items_map.find(key);
if (it == _cache_items_map.end()) {
throw std::range_error("There is no such key in cache");
} else {
_cache_items_list.splice(_cache_items_list.begin(), _cache_items_list, it->second);
return it->second->second;
}
}
bool exists(const key_t& key) const {
return _cache_items_map.find(key) != _cache_items_map.end();
}
size_t size() const {
return _cache_items_map.size();
}
private:
std::list<key_value_pair_t> _cache_items_list;
std::unordered_map<key_t, list_iterator_t> _cache_items_map;
size_t _max_size;
std::list<key_value_pair_t> _cache_items_list;
std::unordered_map<key_t, list_iterator_t> _cache_items_map;
size_t _max_size;
};
} // namespace cache
#endif /* _LRUCACHE_HPP_INCLUDED_ */
} // namespace cache
#endif /* _LRUCACHE_HPP_INCLUDED_ */