com.legstar.coxb.impl.RedefinesMap Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of legstar-distribution
Used to create a single distribution for the entire LegStar project.
The newest version!
/*******************************************************************************
 * Copyright (c) 2011 LegSem.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Contributors:
 *     LegSem - initial API and implementation
 ******************************************************************************/
package com.legstar.coxb.impl;

import java.util.Hashtable;

import com.legstar.coxb.ICobolChoiceBinding;

/**
 * Encapsulates a singleton HashTable to track REDEFINES relationships.
 * The map holds an entry for each redefined object and the associated
 * choice element.
 */
public class RedefinesMap {

    /** 
     * Redefines choice element. This table is populated when an element is
     * being redefined by others (cobol REDEFINES clause). When redefining
     * elements are found, this table will give direct access to the
     * corresponding choice element.              */
    private static
    ThreadLocal < Hashtable < String, ICobolChoiceBinding > > mapHolder
    = new ThreadLocal < Hashtable < String, ICobolChoiceBinding > >();

    /**
     * Gets the current choice element for a redefining object.
     * 
     * @param redefines The cobol element name that is redefined
     * @return the cobol description of the choice element
     */
    public synchronized ICobolChoiceBinding getChoiceElement(final String redefines) {

        ICobolChoiceBinding value = getRedefinesMap().get(redefines);
        return value;
    }

    /**
     * Changes the choice element for this redefining object.
     */
    /**
     * @param redefines cobol variable redefining an element
     * @param ce the cobol description of the redefined element
     */
    public synchronized void updateChoiceElement(
            final String redefines,
            final ICobolChoiceBinding ce) {

        getRedefinesMap().put(redefines, ce);
    }

    /**
     * Removes the choice element from the map.
     * 
     * @param redefines cobol variable redefining an element
     */
    public synchronized void removeChoiceElement(final String redefines) {

        getRedefinesMap().remove(redefines);
    }

    /**
     * Getter for the redefines map.
     * 
     * @return the redefines map
     */
    public Hashtable < String, ICobolChoiceBinding > getRedefinesMap() {

        Hashtable < String, ICobolChoiceBinding > result = mapHolder.get();
        if (result == null) {
            mapHolder.set(new Hashtable < String, ICobolChoiceBinding >());
        }
        return mapHolder.get();
    }

}