mirror of
https://github.com/pocoproject/poco.git
synced 2024-12-23 23:39:23 +01:00
90 lines
3.2 KiB
C++
90 lines
3.2 KiB
C++
//
|
|
// UniqueExpireCache.h
|
|
//
|
|
// $Id: //poco/svn/Foundation/include/Poco/UniqueExpireCache.h#2 $
|
|
//
|
|
// Library: Foundation
|
|
// Package: Cache
|
|
// Module: UniqueExpireCache
|
|
//
|
|
// Definition of the UniqueExpireCache class.
|
|
//
|
|
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person or organization
|
|
// obtaining a copy of the software and accompanying documentation covered by
|
|
// this license (the "Software") to use, reproduce, display, distribute,
|
|
// execute, and transmit the Software, and to prepare derivative works of the
|
|
// Software, and to permit third-parties to whom the Software is furnished to
|
|
// do so, all subject to the following:
|
|
//
|
|
// The copyright notices in the Software and this entire statement, including
|
|
// the above license grant, this restriction and the following disclaimer,
|
|
// must be included in all copies of the Software, in whole or in part, and
|
|
// all derivative works of the Software, unless such copies or derivative
|
|
// works are solely in the form of machine-executable object code generated by
|
|
// a source language processor.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
|
|
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
|
|
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
|
|
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
// DEALINGS IN THE SOFTWARE.
|
|
//
|
|
|
|
|
|
#ifndef Foundation_UniqueExpireCache_INCLUDED
|
|
#define Foundation_UniqueExpireCache_INCLUDED
|
|
|
|
|
|
#include "Poco/AbstractCache.h"
|
|
#include "Poco/UniqueExpireStrategy.h"
|
|
|
|
|
|
namespace Poco {
|
|
|
|
|
|
template <class TKey, class TValue>
|
|
class UniqueExpireCache: public AbstractCache<TKey, TValue, UniqueExpireStrategy<TKey, TValue> >
|
|
/// An UniqueExpireCache caches entries for a given time amount. In contrast
|
|
/// to ExpireCache which only allows to set a per cache expiration value, it allows to define
|
|
/// expiration per CacheEntry.
|
|
/// 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.
|
|
///
|
|
/// Be careful when using an UniqueExpireCache. 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:
|
|
UniqueExpireCache():
|
|
AbstractCache<TKey, TValue, UniqueExpireStrategy<TKey, TValue> >(UniqueExpireStrategy<TKey, TValue>())
|
|
{
|
|
}
|
|
|
|
~UniqueExpireCache()
|
|
{
|
|
}
|
|
|
|
private:
|
|
UniqueExpireCache(const UniqueExpireCache& aCache);
|
|
UniqueExpireCache& operator = (const UniqueExpireCache& aCache);
|
|
};
|
|
|
|
|
|
} // namespace Poco
|
|
|
|
|
|
#endif
|