/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.xml.internal.ws.server.sei;

import com.sun.xml.internal.ws.api.model.Parameter;
import com.sun.xml.internal.ws.model.ParameterImpl;

import javax.xml.ws.Holder;

/**
 * Moves a Java value unmarshalled from a response message
 * to the right place.
 *
 * <p>
 * Sometimes values are returned as a return value, and
 * others are returned in the {@link Holder} value. Instances
 * of this interface abstracts this detail.
 *
 * <p>
 * {@link EndpointValueSetter} is a stateless behavior encapsulation.
 *
 * @author Jitendra Kotamraju
 */
public abstract class EndpointValueSetter {
    private EndpointValueSetter() {}

    /**
     * Moves the value to the expected place.
     *
     * @param obj
     *      The unmarshalled object.
     * @param args
     *      The arguments that need to be given to the Java method invocation. If <tt>obj</tt>
     *      is supposed to be returned as a {@link Holder} value, a suitable
     *      {@link Holder} is obtained from this argument list and <tt>obj</tt>
     *      is set.
     *
     */
    abstract void put(Object obj, Object[] args);

    /**
     * {@link Param}s with small index numbers are used often,
     * so we pool them to reduce the footprint.
     */
    private static final EndpointValueSetter[] POOL = new EndpointValueSetter[16];

    static {
        for( int i=0; i<POOL.length; i++ )
            POOL[i] = new Param(i);
    }

    /**
     * Returns a {@link EndpointValueSetter} suitable for the given {@link Parameter}.
     */
    public static EndpointValueSetter get(ParameterImpl p) {
        int idx = p.getIndex();
        if (p.isIN()) {
            if (idx<POOL.length) {
                return POOL[idx];
            } else {
                return new Param(idx);
            }
        } else {
            return new HolderParam(idx);
        }
    }

    static class Param extends EndpointValueSetter {
        /**
         * Index of the argument to put the value to.
         */
        protected final int idx;

        public Param(int idx) {
            this.idx = idx;
        }

        void put(Object obj, Object[] args) {
            if (obj != null) {
                args[idx] = obj;
            }
        }
    }

    static final class HolderParam extends Param {

        public HolderParam(int idx) {
            super(idx);
        }

        @Override
        void put(Object obj, Object[] args) {
            Holder holder = new Holder();
            if (obj != null) {
                holder.value = obj;
            }
            args[idx] = holder;
        }
    }
}
