insertion_tinylfu.h

#ifndef CACHEMERE_INSERTION_TINYLFU_H
#define CACHEMERE_INSERTION_TINYLFU_H
 
#include <cstdint>
 
#include "cachemere/item.h"
 
#include "detail/bloom_filter.h"
#include "detail/counting_bloom_filter.h"
 
namespace cachemere::policy {
 
template<typename Key, typename KeyHash, typename Value> class InsertionTinyLFU
{
public:
    using CacheItem = cachemere::Item<Value>;
 
    void clear();
 
    void on_cache_hit(const Key& key, const CacheItem& item);
 
    template<typename KeyType> void on_cache_miss(const KeyType& key);
 
    void set_cardinality(uint32_t cardinality);
 
    bool should_add(const Key& key);
 
    bool should_replace(const Key& victim, const Key& candidate);
 
private:
    const static uint32_t                DEFAULT_CACHE_CARDINALITY = 2000;
    detail::BloomFilter<KeyHash>         m_gatekeeper{DEFAULT_CACHE_CARDINALITY};        // TODO: Investigate using cuckoo filter here instead.
    detail::CountingBloomFilter<KeyHash> m_frequency_sketch{DEFAULT_CACHE_CARDINALITY};  // TODO: Replace with count-min sketch to get rid of cardinality param.
 
    uint32_t estimate_count_for_key(const Key& key) const;
    void     reset();
 
    template<typename KeyType> void touch_item(const KeyType& key);
};
 
}  // namespace cachemere::policy
 
#include "insertion_tinylfu.hpp"
 
#endif