mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-10-04 15:40:49 +00:00
68 lines
1.7 KiB
C++
68 lines
1.7 KiB
C++
//
|
|
// ExpireCache.h
|
|
//
|
|
// $Id: //poco/1.4/Foundation/include/Poco/ExpireCache.h#1 $
|
|
//
|
|
// Library: Foundation
|
|
// Package: Cache
|
|
// Module: ExpireCache
|
|
//
|
|
// Definition of the ExpireCache class.
|
|
//
|
|
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef Foundation_ExpireCache_INCLUDED
|
|
#define Foundation_ExpireCache_INCLUDED
|
|
|
|
|
|
#include "Poco/AbstractCache.h"
|
|
#include "Poco/ExpireStrategy.h"
|
|
|
|
|
|
namespace Poco {
|
|
|
|
|
|
template <
|
|
class TKey,
|
|
class TValue,
|
|
class TMutex = FastMutex,
|
|
class TEventMutex = FastMutex
|
|
>
|
|
class ExpireCache: public AbstractCache<TKey, TValue, ExpireStrategy<TKey, TValue>, TMutex, TEventMutex>
|
|
/// An ExpireCache caches entries for a fixed time period (per default 10 minutes).
|
|
/// Entries expire independently of the access pattern, i.e. after a constant time.
|
|
/// If you require your objects to expire after they were not accessed for a given time
|
|
/// period use a Poco::AccessExpireCache.
|
|
///
|
|
/// Be careful when using an ExpireCache. A cache is often used
|
|
/// like cache.has(x) followed by cache.get x). Note that it could happen
|
|
/// that the "has" call works, then the current execution thread gets descheduled, time passes,
|
|
/// the entry gets invalid, thus leading to an empty SharedPtr being returned
|
|
/// when "get" is invoked.
|
|
{
|
|
public:
|
|
ExpireCache(Timestamp::TimeDiff expire = 600000):
|
|
AbstractCache<TKey, TValue, ExpireStrategy<TKey, TValue>, TMutex, TEventMutex>(ExpireStrategy<TKey, TValue>(expire))
|
|
{
|
|
}
|
|
|
|
~ExpireCache()
|
|
{
|
|
}
|
|
|
|
private:
|
|
ExpireCache(const ExpireCache& aCache);
|
|
ExpireCache& operator = (const ExpireCache& aCache);
|
|
};
|
|
|
|
|
|
} // namespace Poco
|
|
|
|
|
|
#endif // Foundation_ExpireCache_INCLUDED
|