coherence/util/filter/FilterTrigger.hpp

/*
* FilterTrigger.hpp
*
* Copyright (c) 2000, 2009, Oracle and/or its affiliates. All rights reserved.
*
* Oracle is a registered trademarks of Oracle Corporation and/or its
* affiliates.
*
* This software is the confidential and proprietary information of Oracle
* Corporation. You shall not disclose such confidential and proprietary
* information and shall use it only in accordance with the terms of the
* license agreement you entered into with Oracle.
*
* This notice may not be removed or altered.
*/
#ifndef COH_FILTER_TRIGGER_HPP
#define COH_FILTER_TRIGGER_HPP

#include "coherence/lang.ns"

#include "coherence/io/pof/PofReader.hpp"
#include "coherence/io/pof/PofWriter.hpp"
#include "coherence/io/pof/PortableObject.hpp"
#include "coherence/util/Filter.hpp"
#include "coherence/util/MapTrigger.hpp"

COH_OPEN_NAMESPACE3(coherence,util,filter)

using coherence::io::pof::PofReader;
using coherence::io::pof::PofWriter;
using coherence::io::pof::PortableObject;


/**
* A generic Filter-based MapTrigger implementation. If an evaluation of the
* coherence::util::MapTrigger::Entry object representing a pending
* change fails (returns false), then one of the following actions is taken:
* <ul>
*   <li> ACTION_ROLLBACK - an IllegalArgumentException is thrown by the
*        trigger to reject the operation that would result in this change
*        (default);
*   <li> ACTION_IGNORE - the change is ignored and the Entry's value is reset
*        to the original value returned by the
*        coherence::util::MapTrigger::Entry#getOriginalValue() method;
*   <li> ACTION_REMOVE - the entry is removed from the underlying backing map
*        using the coherence::util::InvocableMap::Entry#remove(boolean) call.
* </ul>
*
* Note: This trigger never prevent entries from being removed.
*
* @author djl  2008.05.22
*/
class COH_EXPORT FilterTrigger
    : public class_spec<FilterTrigger,
        extends<Object>,
        implements<PortableObject, MapTrigger> >
    {
    friend class factory<FilterTrigger>;

    // ----- constructors ---------------------------------------------------

    protected:
        /**
        * Default constructor (necessary for the PortableObject interface).
        */
        FilterTrigger();

        /**
        * Construct a FilterTrigger based on the specified Filter object and
        * the action constant.
        *
        * @param vFilter  the underlying Filter
        * @param nAction  one of the ACTION_* constants
        */
        FilterTrigger(Filter::View vFilter, int32_t nAction);


    // ----- MapTrigger interface -------------------------------------------

    public:
        /**
        * {@inheritDoc}
        */
        virtual void process(MapTrigger::Entry::Handle vEntry);


   // ----- PortableObject interface ---------------------------------------

     public:
        /**
        * {@inheritDoc}
        */
        virtual void readExternal(PofReader::Handle hIn);

        /**
        * {@inheritDoc}
        */
        virtual void writeExternal(PofWriter::Handle hOut) const;


    // ----- Object interface -----------------------------------------------

    public:
        /**
        * {@inheritDoc}
        */
        virtual bool equals(Object::View v) const;

        /**
        * {@inheritDoc}
        */
        virtual size32_t hashCode() const;

        /**
        * {@inheritDoc}
        */
        virtual void toStream(std::ostream& out) const;


    // ----- data member accessors ------------------------------------------

    public:
        /**
        * Obtain the underlying Filter.
        *
        * @return the underlying Filter object
        */
        virtual Filter::View getFilter() const;

        /**
        * Obtain the action code for this FilterTrigger.
        *
        * @return one of the ACTION_* constants
        */
        virtual int32_t getAction() const;


    // ----- constants ------------------------------------------------------

    public:
        /**
        * Evaluation failure results in an IllegalArgumentException thrown
        * by the trigger.
        */
        static const int32_t ACTION_ROLLBACK = 0;

        /**
        * Evaluation failure results in restoring the original Entry's value.
        */
        static const int32_t ACTION_IGNORE = 1;

        /**
        * Evaluation failure results in a removal of the entry.
        */
        static const int32_t ACTION_REMOVE = 2;


    // ----- data members ---------------------------------------------------

    protected:
        /**
        * The underlying filter.
        */
        MemberView<Filter> m_vFilter;

        /**
        * The action code.
        */
        int32_t m_nAction;
    };

COH_CLOSE_NAMESPACE3

#endif // COH_FILTER_TRIGGER_HPP

Copyright (c) 2000, 2009, Oracle and/or its affiliates. All rights reserved.