forked from blue/lmdbal
58 lines
1.8 KiB
C++
58 lines
1.8 KiB
C++
// Squawk messenger.
|
|
// Copyright (C) 2019 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 DATABASE_CACHE_H
|
|
#define DATABASE_CACHE_H
|
|
|
|
#include "database.h"
|
|
#include "table.h"
|
|
#include <map>
|
|
#include <set>
|
|
|
|
template <class K, class V>
|
|
class DataBase::Cache : public DataBase::Table<K, V> {
|
|
friend class DataBase;
|
|
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, DataBase* parent);
|
|
~Cache() override;
|
|
|
|
private:
|
|
void handleMode() const;
|
|
|
|
public:
|
|
virtual void addRecord(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 V getRecord(const K& key) const override;
|
|
virtual uint32_t count() const override;
|
|
virtual void drop() override;
|
|
|
|
protected:
|
|
Mode* mode;
|
|
std::map<K, V>* cache;
|
|
std::set<K>* abscent;
|
|
uint32_t* sizeDifference;
|
|
};
|
|
|
|
#include "cache.hpp"
|
|
|
|
#endif // DATABASE_CACHE_H
|