poco/Foundation/include/Poco/AbstractStrategy.h
2015-04-10 11:31:12 +01:00

80 lines
2.0 KiB
C++

//
// AbstractStrategy.h
//
// $Id: //poco/1.4/Foundation/include/Poco/AbstractStrategy.h#1 $
//
// Library: Foundation
// Package: Cache
// Module: AbstractCache
//
// Definition of the AbstractStrategy class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_AbstractStrategy_INCLUDED
#define Foundation_AbstractStrategy_INCLUDED
#include "Poco/KeyValueArgs.h"
#include "Poco/ValidArgs.h"
#include "Poco/EventArgs.h"
#include <set>
namespace Poco {
template <class TKey, class TValue>
class AbstractStrategy
/// An AbstractStrategy is the interface for all strategies.
{
public:
AbstractStrategy()
{
}
virtual ~AbstractStrategy()
{
}
virtual void onUpdate(const void* pSender, const KeyValueArgs <TKey, TValue>& args)
/// Updates an existing entry.
{
onRemove(pSender,args.key());
onAdd(pSender, args);
}
virtual void onAdd(const void* pSender, const KeyValueArgs <TKey, TValue>& key) = 0;
/// Adds the key to the strategy.
/// If for the key already an entry exists, an exception will be thrown.
virtual void onRemove(const void* pSender, const TKey& key) = 0;
/// Removes an entry from the strategy. If the entry is not found
/// the remove is ignored.
virtual void onGet(const void* pSender, const TKey& key) = 0;
/// Informs the strategy that a read-access happens to an element.
virtual void onClear(const void* pSender, const EventArgs& args) = 0;
/// Removes all elements from the cache.
virtual void onIsValid(const void* pSender, ValidArgs<TKey>& key) = 0;
/// Used to query if a key is still valid (i.e. cached).
virtual void onReplace(const void* pSender, std::set<TKey>& elemsToRemove) = 0;
/// Used by the Strategy to indicate which elements should be removed from
/// the cache. Note that onReplace does not change the current list of keys.
/// The cache object is responsible to remove the elements.
};
} // namespace Poco
#endif // Foundation_AbstractStrategy_INCLUDED