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75 lines
2.0 KiB
C++
75 lines
2.0 KiB
C++
//
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// AbstractStrategy.h
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//
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// Library: Foundation
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// Package: Cache
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// Module: AbstractCache
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//
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// Definition of the AbstractStrategy 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_AbstractStrategy_INCLUDED
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#define Foundation_AbstractStrategy_INCLUDED
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#include <set>
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#include "Poco/EventArgs.h"
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#include "Poco/KeyValueArgs.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 AbstractStrategy
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/// An AbstractStrategy is the interface for all strategies.
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{
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public:
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AbstractStrategy() { }
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virtual ~AbstractStrategy() { }
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virtual void onUpdate(const void * pSender, const KeyValueArgs<TKey, TValue> & args)
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/// Updates an existing entry.
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{
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onRemove(pSender, args.key());
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onAdd(pSender, args);
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}
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virtual void onAdd(const void * pSender, const KeyValueArgs<TKey, TValue> & key) = 0;
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/// Adds the key to the strategy.
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/// If for the key already an entry exists, an exception will be thrown.
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virtual void onRemove(const void * pSender, const TKey & key) = 0;
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/// Removes an entry from the strategy. If the entry is not found
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/// the remove is ignored.
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virtual void onGet(const void * pSender, const TKey & key) = 0;
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/// Informs the strategy that a read-access happens to an element.
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virtual void onClear(const void * pSender, const EventArgs & args) = 0;
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/// Removes all elements from the cache.
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virtual void onIsValid(const void * pSender, ValidArgs<TKey> & key) = 0;
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/// Used to query if a key is still valid (i.e. cached).
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virtual void onReplace(const void * pSender, std::set<TKey> & elemsToRemove) = 0;
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/// Used by the Strategy to indicate which elements should be removed from
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/// the cache. Note that onReplace does not change the current list of keys.
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/// The cache object is responsible to remove the elements.
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};
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} // namespace Poco
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#endif // Foundation_AbstractStrategy_INCLUDED
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