ClickHouse/contrib/libpoco/Foundation/include/Poco/UniqueExpireLRUCache.h

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2.0 KiB
C++

//
// UniqueExpireLRUCache.h
//
// $Id: //poco/1.4/Foundation/include/Poco/UniqueExpireLRUCache.h#1 $
//
// 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/StrategyCollection.h"
#include "Poco/UniqueExpireStrategy.h"
#include "Poco/LRUStrategy.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 seperate 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