ClickHouse/base/poco/Foundation/include/Poco/UniqueExpireLRUCache.h

//
// UniqueExpireLRUCache.h
//
// Library: Foundation
// Package: Cache
// Module:  UniqueExpireLRUCache
//
// Definition of the UniqueExpireLRUCache class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_UniqueExpireLRUCache_INCLUDED
#define Foundation_UniqueExpireLRUCache_INCLUDED


#include "Poco/AbstractCache.h"
#include "Poco/LRUStrategy.h"
#include "Poco/StrategyCollection.h"
#include "Poco/UniqueExpireStrategy.h"


namespace Poco
{


template <class TKey, class TValue, class TMutex = FastMutex, class TEventMutex = FastMutex>
class UniqueExpireLRUCache : public AbstractCache<TKey, TValue, StrategyCollection<TKey, TValue>, TMutex, TEventMutex>
/// A UniqueExpireLRUCache combines LRU caching and time based per entry expire caching.
/// One can define for each cache entry a separate timepoint
/// but also limit the size of the cache (per default: 1024).
/// Each TValue object must thus offer the following method:
///
///    const Poco::Timestamp& getExpiration() const;
///
/// which returns the absolute timepoint when the entry will be invalidated.
/// Accessing an object will NOT update this absolute expire timepoint.
/// You can use the Poco::ExpirationDecorator to add the getExpiration
/// method to values that do not have a getExpiration function.
{
public:
    UniqueExpireLRUCache(long cacheSize = 1024)
        : AbstractCache<TKey, TValue, StrategyCollection<TKey, TValue>, TMutex, TEventMutex>(StrategyCollection<TKey, TValue>())
    {
        this->_strategy.pushBack(new LRUStrategy<TKey, TValue>(cacheSize));
        this->_strategy.pushBack(new UniqueExpireStrategy<TKey, TValue>());
    }

    ~UniqueExpireLRUCache() { }

private:
    UniqueExpireLRUCache(const UniqueExpireLRUCache & aCache);
    UniqueExpireLRUCache & operator=(const UniqueExpireLRUCache & aCache);
};


} // namespace Poco


#endif // Foundation_UniqueExpireLRUCache_INCLUDED