coherence/util/extractor/PofExtractor.hpp

/*
* PofExtractor.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_POF_EXTRACTOR_HPP
#define COH_POF_EXTRACTOR_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/io/pof/reflect/PofNavigator.hpp"
#include "coherence/util/extractor/AbstractExtractor.hpp"

COH_OPEN_NAMESPACE3(coherence,util,extractor)

using coherence::io::pof::PofReader;
using coherence::io::pof::PofWriter;
using coherence::io::pof::reflect::PofNavigator;


/**
* POF-based ValueExtractor implementation.
*
* @author as/gm 2009.04.02
* @since Coherence 3.5
*/
class COH_EXPORT PofExtractor
    : public class_spec<PofExtractor,
        extends<AbstractExtractor>,
        implements<PortableObject> >
    {
    friend class factory<PofExtractor>;

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

    protected:
        /**
        * Default constructor (for backward compatibility).
        */
        PofExtractor();

        /**
        * Constructs a PofExtractor based on a property index.
        * <p/>
        * This constructor is equivalent to:
        * <pre>
        *   PofExtractor::View vExtractor =
        *       PofExtractor::create(SimplePofPath::create(iProp), VALUE);
        * </pre>
        *
        * @param iProp  property index
        */
        PofExtractor(int32_t iProp);

        /**
        * Constructs a PofExtractor based on a property path and the entry
        * extraction target.
        *
        * @param vNavigator  POF navigator
        * @param nTarget     one of the {@link #VALUE} or {@link #KEY} values
        */
        PofExtractor(PofNavigator::View vNavigator, int32_t nTarget = VALUE);


    // ----- AbstractExtractor methods ---------------------------------------

    public:
        /**
        * Extract the value from the passed Entry object. The returned value
        * should follow the conventions outlined in the {@link #extract}
        * method.
        * <p/>
        * This method will always throw a
        * {@link UnsupportedOperationException} if called directly by the
        * C++ client application, as its execution is only meaningful within
        * the cluster.
        * <p/>
        * It is expected that this extractor will only be used against
        * POF-encoded binary entries within a remote partitioned cache.
        *
        * @param entry  an Entry object to extract a desired value from
        *
        * @throws UnsupportedOperationException  always, as it is expected
        *         that this extractor will only be executed within the
        *         cluster.
        *
        * @return the extracted value
        */
        virtual Object::Holder extractFromEntry(Map::Entry::Holder ohEntry) const;


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

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

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


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

    public:
        /**
        * Compare the PofExtractor with another object to determine equality.
        * Two PofExtractor objects are considered equal iff their paths are
        * equal and they have the same target (key or value).
        *
        * @return true iff this PofExtractor and the passed object are
        *              equivalent
        */
        virtual bool equals(Object::View v) const;

        /**
        * Determine a hash value for the PofExtractor object according to the
        * general {@link Object#hashCode()} contract.
        *
        * @return an integer hash value for this PofExtractor object
        */
        virtual size32_t hashCode() const;

        /**
        * Return a human-readable description for this PofExtractor.
        *
        * @return a String description of the PofExtractor
        */
        virtual void toStream(std::ostream& out) const;


    // ----- accessors ------------------------------------------------------

    public:
        /**
        * Obtain the PofPath for this extractor.
        *
        * @return the PofPath value
        */
        virtual PofNavigator::View getNavigator() const;


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

    private:
        /**
        * POF navigator.
        */
        FinalView<PofNavigator> m_vNavigator;
    };

COH_CLOSE_NAMESPACE3

#endif // #define COH_POF_EXTRACTOR_HPP

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