topical media & game development
lib-of-vs-libs-Poco-include-Poco-ExpireCache.h / h
//
// ExpireCache.h
//
//
//
// Library: Foundation
// Package: Cache
// Module: ExpireCache
//
// Definition of the ExpireCache 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_ExpireCache_INCLUDED
define Foundation_ExpireCache_INCLUDED
include "Poco/AbstractCache.h"
include "Poco/ExpireStrategy.h"
namespace Poco {
template <class TKey, class TValue>
class ExpireCache: public AbstractCache<TKey, TValue, ExpireStrategy<TKey, TValue> >
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> >(ExpireStrategy<TKey, TValue>(expire))
{
}
~ExpireCache()
{
}
private:
ExpireCache(const ExpireCache& aCache);
ExpireCache& operator = (const ExpireCache& aCache);
};
} // namespace Poco
endif
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
