org.plasma.sdo.access.provider.common.DataObjectPathDepthComparator.java Source code

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Here is the source code for org.plasma.sdo.access.provider.common.DataObjectPathDepthComparator.java

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/**
 *         PlasmaSDO License
 * 
 * This is a community release of PlasmaSDO, a dual-license 
 * Service Data Object (SDO) 2.1 implementation. 
 * This particular copy of the software is released under the 
 * version 2 of the GNU General Public License. PlasmaSDO was developed by 
 * TerraMeta Software, Inc.
 * 
 * Copyright (c) 2013, TerraMeta Software, Inc. All rights reserved.
 * 
 * General License information can be found below.
 * 
 * This distribution may include materials developed by third
 * parties. For license and attribution notices for these
 * materials, please refer to the documentation that accompanies
 * this distribution (see the "Licenses for Third-Party Components"
 * appendix) or view the online documentation at 
 * <http://plasma-sdo.org/licenses/>.
 *  
 */
package org.plasma.sdo.access.provider.common;

import java.util.Comparator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.plasma.sdo.PlasmaChangeSummary;

import commonj.sdo.DataObject;

/**
 * Compares its two data-objects for path depth relative to a data-graph root.     
 * 
 */
public class DataObjectPathDepthComparator implements Comparator<DataObject> {

    private static Log log = LogFactory.getFactory().getInstance(DataObjectPathDepthComparator.class);

    /**
     * Returns a negative integer, 
     * zero, or a positive integer as the first argument is less 
     * than, equal to, or greater than the second.
     */
    public int compare(DataObject target, DataObject source) {

        if (target.getDataGraph() == null)
            throw new IllegalArgumentException("target data-object has no data-graph - "
                    + "data-objects compared for commit operations must have a data graph");
        if (source.getDataGraph() == null)
            throw new IllegalArgumentException("source data-object has no data-graph - "
                    + "data-objects compared for commit operations must have a data graph");

        PlasmaChangeSummary changeSummary = (PlasmaChangeSummary) target.getChangeSummary();

        int targetDepth = changeSummary.getPathDepth(target);
        int sourceDepth = changeSummary.getPathDepth(source);

        int result = 0;

        if (changeSummary.isCreated(target)) {
            if (targetDepth > sourceDepth)
                result = 1;
            else if (sourceDepth > targetDepth)
                result = -1;
            else
                result = 0;
        } else if (changeSummary.isModified(target)) {
            if (targetDepth > sourceDepth)
                result = 1;
            else if (sourceDepth > targetDepth)
                result = -1;
            else
                result = 0;
        } else { // deleted
            if (targetDepth > sourceDepth)
                result = -1;
            else if (sourceDepth > targetDepth)
                result = 1;
            else
                result = 0;
        }

        return result;
    }
}