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

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//
// UniqueAccessExpireLRUCache.h
//
// $Id: //poco/1.4/Foundation/include/Poco/UniqueAccessExpireLRUCache.h#1 $
//
// Library: Foundation
// Package: Cache
// Module: UniqueAccessExpireLRUCache
//
// Definition of the UniqueAccessExpireLRUCache class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_UniqueAccessExpireLRUCache_INCLUDED
#define Foundation_UniqueAccessExpireLRUCache_INCLUDED
#include "Poco/AbstractCache.h"
#include "Poco/StrategyCollection.h"
#include "Poco/UniqueAccessExpireStrategy.h"
#include "Poco/LRUStrategy.h"
namespace Poco {
template <
class TKey,
class TValue,
class TMutex = FastMutex,
class TEventMutex = FastMutex
>
class UniqueAccessExpireLRUCache: public AbstractCache<TKey, TValue, StrategyCollection<TKey, TValue>, TMutex, TEventMutex>
/// A UniqueAccessExpireLRUCache 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::Timespan& getTimeout() const;
///
/// which returns the relative timespan for how long the entry should be valid without being accessed!
/// The absolute expire timepoint is calculated as now() + getTimeout().
/// Accessing an object will update this absolute expire timepoint.
/// You can use the Poco::AccessExpirationDecorator to add the getExpiration
/// method to values that do not have a getExpiration function.
{
public:
UniqueAccessExpireLRUCache(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 UniqueAccessExpireStrategy<TKey, TValue>());
}
~UniqueAccessExpireLRUCache()
{
}
private:
UniqueAccessExpireLRUCache(const UniqueAccessExpireLRUCache& aCache);
UniqueAccessExpireLRUCache& operator = (const UniqueAccessExpireLRUCache& aCache);
};
} // namespace Poco
#endif // Foundation_UniqueAccessExpireLRUCache_INCLUDED