mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-04 21:42:39 +00:00
58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
//
|
|
// AccessExpireCache.h
|
|
//
|
|
// Library: Foundation
|
|
// Package: Cache
|
|
// Module: AccessExpireCache
|
|
//
|
|
// Definition of the AccessExpireCache class.
|
|
//
|
|
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef Foundation_AccessExpireCache_INCLUDED
|
|
#define Foundation_AccessExpireCache_INCLUDED
|
|
|
|
|
|
#include "Poco/AbstractCache.h"
|
|
#include "Poco/AccessExpireStrategy.h"
|
|
|
|
|
|
namespace Poco
|
|
{
|
|
|
|
|
|
template <class TKey, class TValue, class TMutex = FastMutex, class TEventMutex = FastMutex>
|
|
class AccessExpireCache : public AbstractCache<TKey, TValue, AccessExpireStrategy<TKey, TValue>, TMutex, TEventMutex>
|
|
/// An AccessExpireCache caches entries for a fixed time period (per default 10 minutes).
|
|
/// Entries expire when they are not accessed with get() during this time period. Each access resets
|
|
/// the start time for expiration.
|
|
/// Be careful when using an AccessExpireCache. 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:
|
|
AccessExpireCache(Timestamp::TimeDiff expire = 600000)
|
|
: AbstractCache<TKey, TValue, AccessExpireStrategy<TKey, TValue>, TMutex, TEventMutex>(AccessExpireStrategy<TKey, TValue>(expire))
|
|
{
|
|
}
|
|
|
|
~AccessExpireCache() { }
|
|
|
|
private:
|
|
AccessExpireCache(const AccessExpireCache & aCache);
|
|
AccessExpireCache & operator=(const AccessExpireCache & aCache);
|
|
};
|
|
|
|
|
|
} // namespace Poco
|
|
|
|
|
|
#endif // Foundation_AccessExpireCache_INCLUDED
|