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71 lines
1.9 KiB
C++
71 lines
1.9 KiB
C++
//
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// AccessExpireStrategy.h
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//
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// Library: Foundation
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// Package: Cache
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// Module: AccessExpireStrategy
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//
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// Definition of the AccessExpireStrategy class.
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//
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// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
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// and Contributors.
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//
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// SPDX-License-Identifier: BSL-1.0
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//
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#ifndef Foundation_AccessExpireStrategy_INCLUDED
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#define Foundation_AccessExpireStrategy_INCLUDED
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#include <map>
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#include <set>
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#include "Poco/Bugcheck.h"
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#include "Poco/EventArgs.h"
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#include "Poco/ExpireStrategy.h"
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#include "Poco/KeyValueArgs.h"
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#include "Poco/Timestamp.h"
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#include "Poco/ValidArgs.h"
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namespace Poco
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{
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template <class TKey, class TValue>
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class AccessExpireStrategy : public ExpireStrategy<TKey, TValue>
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/// An AccessExpireStrategy implements time and access based expiration of cache entries
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{
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public:
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AccessExpireStrategy(Timestamp::TimeDiff expireTimeInMilliSec) : ExpireStrategy<TKey, TValue>(expireTimeInMilliSec)
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/// Create an expire strategy. Note that the smallest allowed caching time is 25ms.
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/// Anything lower than that is not useful with current operating systems.
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{
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}
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~AccessExpireStrategy() { }
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void onGet(const void *, const TKey & key)
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{
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// get triggers an update to the expiration time
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typename ExpireStrategy<TKey, TValue>::Iterator it = this->_keys.find(key);
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if (it != this->_keys.end())
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{
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if (!it->second->first.isElapsed(this->_expireTime)) // don't extend if already expired
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{
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this->_keyIndex.erase(it->second);
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Timestamp now;
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typename ExpireStrategy<TKey, TValue>::IndexIterator itIdx
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= this->_keyIndex.insert(typename ExpireStrategy<TKey, TValue>::TimeIndex::value_type(now, key));
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it->second = itIdx;
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}
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}
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}
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};
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} // namespace Poco
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#endif // Foundation_AccessExpireStrategy_INCLUDED
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