ClickHouse/base/poco/Foundation/include/Poco/StrategyCollection.h

//
// StrategyCollection.h
//
// Library: Foundation
// Package: Cache
// Module:  StrategyCollection
//
// Definition of the StrategyCollection class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_StrategyCollection_INCLUDED
#define Foundation_StrategyCollection_INCLUDED


#include <vector>
#include "Poco/AbstractStrategy.h"
#include "Poco/KeyValueArgs.h"
#include "Poco/SharedPtr.h"
#include "Poco/ValidArgs.h"


namespace Poco
{


template <class TKey, class TValue>
class StrategyCollection : public AbstractStrategy<TKey, TValue>
/// An StrategyCollection is a decorator masking n collections as a single one.
{
public:
    typedef std::vector<SharedPtr<AbstractStrategy<TKey, TValue>>> Strategies;
    typedef typename Strategies::iterator Iterator;
    typedef typename Strategies::const_iterator ConstIterator;

public:
    StrategyCollection() { }

    ~StrategyCollection() { }

    void pushBack(AbstractStrategy<TKey, TValue> * pStrat)
    /// Adds an AbstractStrategy to the collection. Class takes ownership of pointer
    {
        _strategies.push_back(SharedPtr<AbstractStrategy<TKey, TValue>>(pStrat));
    }

    void popBack()
    /// Removes the last added AbstractStrategy from the collection.
    {
        _strategies.pop_back();
    }

    void onAdd(const void * pSender, const KeyValueArgs<TKey, TValue> & key)
    /// Adds the key to the strategy.
    /// If for the key already an entry exists, it will be overwritten.
    {
        Iterator it = _strategies.begin();
        Iterator endIt = _strategies.end();
        for (; it != endIt; ++it)
        {
            (*it)->onAdd(pSender, key);
        }
    }

    void onRemove(const void * pSender, const TKey & key)
    /// Removes an entry from the strategy. If the entry is not found
    /// the remove is ignored.
    {
        Iterator it = _strategies.begin();
        Iterator endIt = _strategies.end();
        for (; it != endIt; ++it)
        {
            (*it)->onRemove(pSender, key);
        }
    }

    void onGet(const void * pSender, const TKey & key)
    {
        Iterator it = _strategies.begin();
        Iterator endIt = _strategies.end();
        for (; it != endIt; ++it)
        {
            (*it)->onGet(pSender, key);
        }
    }

    void onClear(const void * pSender, const EventArgs & args)
    {
        Iterator it = _strategies.begin();
        Iterator endIt = _strategies.end();
        for (; it != endIt; ++it)
        {
            (*it)->onClear(pSender, args);
        }
    }

    void onIsValid(const void * pSender, ValidArgs<TKey> & key)
    {
        Iterator it = _strategies.begin();
        Iterator endIt = _strategies.end();
        for (; it != endIt && key.isValid(); ++it)
        {
            (*it)->onIsValid(pSender, key);
        }
    }

    void onReplace(const void * pSender, std::set<TKey> & elemsToRemove)
    {
        Iterator it = _strategies.begin();
        Iterator endIt = _strategies.end();
        for (; it != endIt; ++it)
        {
            (*it)->onReplace(pSender, elemsToRemove);
        }
    }

protected:
    Strategies _strategies;
};


} // namespace Poco


#endif // Foundation_StrategyCollection_INCLUDED