mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-29 19:12:03 +00:00
60 lines
1.6 KiB
C++
60 lines
1.6 KiB
C++
//
|
|
// ExpireCache.h
|
|
//
|
|
// 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
|