lmdbal/src/cache.h

71 lines
2.2 KiB
C++

/*
* LMDB Abstraction Layer.
* Copyright (C) 2023 Yury Gubich <blue@macaw.me>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LMDBAL_CACHE_H
#define LMDBAL_CACHE_H
#include <map>
#include <set>
#include "storage.h"
namespace LMDBAL {
template <class K, class V>
class Cache : public Storage<K, V> {
friend class Base;
enum class Mode { //it's a cache state when we:
nothing, // - know nothing about records in database on disk
size, // - know just an amount of records
full // - shure that our cache is equal to the database on disk
};
protected:
Cache(const std::string& name, Base* parent);
~Cache() override;
private:
void handleMode() const;
public:
virtual void addRecord(const K& key, const V& value) override;
virtual bool forceRecord(const K& key, const V& value) override;
virtual void changeRecord(const K& key, const V& value) override;
virtual void removeRecord(const K& key) override;
virtual bool checkRecord(const K& key) const override;
virtual V getRecord(const K& key) const override;
virtual uint32_t count() const override;
using Storage<K, V>::drop;
virtual int drop(MDB_txn * transaction) override;
virtual std::map<K, V> readAll() const override;
virtual void replaceAll(const std::map<K, V>& data) override;
virtual uint32_t addRecords(const std::map<K, V>& data, bool overwrite = false) override;
protected:
Mode* mode;
std::map<K, V>* cache;
std::set<K>* abscent;
uint32_t* sizeDifference;
};
}
#include "cache.hpp"
#endif // LMDBAL_CACHE_H