org.apache.commons.jrcs.diff.Revision.java Source code

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/*
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2003 The Apache Software Foundation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.jrcs.diff;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

import org.apache.commons.jrcs.util.ToString;

/**
 * A Revision holds the series of deltas that describe the differences between
 * two sequences.
 * 
 * @version $Revision$ $Date: 2006-04-12 18:30:19 +0100 (Wed, 12 Apr
 *          2006) $
 * @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a>
 * @author <a href="mailto:bwm@hplb.hpl.hp.com">Brian McBride</a>
 * @see Delta
 * @see Diff
 * @see Chunk
 * @see Revision modifications 27 Apr 2003 bwm Added visitor pattern Visitor
 *      interface and accept() method.
 */

public class Revision extends ToString {

    List deltas_ = new LinkedList();

    /**
     * Creates an empty Revision.
     */
    public Revision() {
    }

    /**
     * Adds a delta to this revision.
     * 
     * @param delta
     *        the {@link Delta Delta} to add.
     */
    public synchronized void addDelta(Delta delta) {
        if (delta == null) {
            throw new IllegalArgumentException("new delta is null");
        }
        deltas_.add(delta);
    }

    /**
     * Adds a delta to the start of this revision.
     * 
     * @param delta
     *        the {@link Delta Delta} to add.
     */
    public synchronized void insertDelta(Delta delta) {
        if (delta == null) {
            throw new IllegalArgumentException("new delta is null");
        }
        deltas_.add(0, delta);
    }

    /**
     * Retrieves a delta from this revision by position.
     * 
     * @param i
     *        the position of the delta to retrieve.
     * @return the specified delta
     */
    public Delta getDelta(int i) {
        return (Delta) deltas_.get(i);
    }

    /**
     * Returns the number of deltas in this revision.
     * 
     * @return the number of deltas.
     */
    public int size() {
        return deltas_.size();
    }

    /**
     * Applies the series of deltas in this revision as patches to the given
     * text.
     * 
     * @param src
     *        the text to patch, which the method doesn't change.
     * @return the resulting text after the patches have been applied.
     * @throws PatchFailedException
     *         if any of the patches cannot be applied.
     */
    public Object[] patch(Object[] src) throws PatchFailedException {
        List target = new ArrayList(Arrays.asList(src));
        applyTo(target);
        return target.toArray();
    }

    /**
     * Applies the series of deltas in this revision as patches to the given
     * text.
     * 
     * @param target
     *        the text to patch.
     * @throws PatchFailedException
     *         if any of the patches cannot be applied.
     */
    public synchronized void applyTo(List target) throws PatchFailedException {
        ListIterator i = deltas_.listIterator(deltas_.size());
        while (i.hasPrevious()) {
            Delta delta = (Delta) i.previous();
            delta.patch(target);
        }
    }

    /**
     * Converts this revision into its Unix diff style string representation.
     * 
     * @param s
     *        a {@link StringBuffer StringBuffer} to which the string
     *        representation will be appended.
     */
    public synchronized void toString(StringBuffer s) {
        Iterator i = deltas_.iterator();
        while (i.hasNext()) {
            ((Delta) i.next()).toString(s);
        }
    }

    /**
     * Converts this revision into its RCS style string representation.
     * 
     * @param s
     *        a {@link StringBuffer StringBuffer} to which the string
     *        representation will be appended.
     * @param EOL
     *        the string to use as line separator.
     */
    public synchronized void toRCSString(StringBuffer s, String EOL) {
        Iterator i = deltas_.iterator();
        while (i.hasNext()) {
            ((Delta) i.next()).toRCSString(s, EOL);
        }
    }

    /**
     * Converts this revision into its RCS style string representation.
     * 
     * @param s
     *        a {@link StringBuffer StringBuffer} to which the string
     *        representation will be appended.
     */
    public void toRCSString(StringBuffer s) {
        toRCSString(s, Diff.NL);
    }

    /**
     * Converts this delta into its RCS style string representation.
     * 
     * @param EOL
     *        the string to use as line separator.
     */
    public String toRCSString(String EOL) {
        StringBuffer s = new StringBuffer();
        toRCSString(s, EOL);
        return s.toString();
    }

    /**
     * Converts this delta into its RCS style string representation using the
     * default line separator.
     */
    public String toRCSString() {
        return toRCSString(Diff.NL);
    }

    /**
     * Accepts a visitor.
     * 
     * @param visitor
     *        the {@link Visitor} visiting this instance
     */
    public void accept(RevisionVisitor visitor) {
        visitor.visit(this);
        Iterator iter = deltas_.iterator();
        while (iter.hasNext()) {
            ((Delta) iter.next()).accept(visitor);
        }
    }

}