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Posted to dev@commons.apache.org by ju...@apache.org on 2003/05/10 20:56:10 UTC

cvs commit: jakarta-commons-sandbox/jrcs/src/java/org/apache/commons/jrcs/diff/myers DiffNode.java Snake.java package.html

juanco      2003/05/10 11:56:10

  Added:       jrcs/src/java/org/apache/commons/jrcs/diff/myers
                        DiffNode.java Snake.java package.html
  Log:
  Added memory optimizations to Myers' diff algorithm. Now there are no out-of-memory errors for up to 8k of shuffled, or totally different items.
  
  Revision  Changes    Path
  1.1                  jakarta-commons-sandbox/jrcs/src/java/org/apache/commons/jrcs/diff/myers/DiffNode.java
  
  Index: DiffNode.java
  ===================================================================
  package org.apache.commons.jrcs.diff.myers;
  
  /**
   * <p>Title: </p>
   * <p>Description: </p>
   * <p>Copyright: Copyright (c) 2002</p>
   * <p>Company: </p>
   * @author not attributable
   * @version 1.0
   */
  
  /**
   * A diffnode in a diffpath.
   * <p>
   * A DiffNode and its previous node mark a delta between
   * two input sequences, that is, two differing subsequences
   * between (possibly zero length) matching sequences.
   *
   * {@link DiffNode DiffNodes} and {@link Snake Snakes} allow for compression
   * of diffpaths, as each snake is represented by a single {@link Snake Snake}
   * node and each contiguous series of insertions and deletions is represented
   * by a single {@link DiffNode DiffNodes}.
   *
   * @version $Revision: 1.1 $ $Date: 2003/05/10 18:56:10 $
   * @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a>
   *
   */
  public final class DiffNode
      extends PathNode
  {
      /**
       * Constructs a DiffNode.
       * <p>
       * DiffNodes are compressed. That means that
       * the path pointed to by the <code>prev</code> parameter
       * will be followed using {@link PathNode#previousSnake}
       * until a non-diff node is found.
       *
       * @param the position in the original sequence
       * @param the position in the revised sequence
       * @param prev the previous node in the path.
       */
      public DiffNode(int i, int j, PathNode prev)
      {
          super(i, j, (prev == null ? null : prev.previousSnake()) );
      }
  
      /**
       * {@inheritDoc}
       * @return false, always
       */
      public boolean isSnake()
      {
          return false;
      }
  
  }
  
  
  1.1                  jakarta-commons-sandbox/jrcs/src/java/org/apache/commons/jrcs/diff/myers/Snake.java
  
  Index: Snake.java
  ===================================================================
  /*
   * ====================================================================
   *
   * 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 acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements 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 Group.
   *
   * 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.myers;
  
  /**
   *  Represents a snake in a diffpath.
   * <p>
   *
   * {@link DiffNode DiffNodes} and {@link Snake Snakes} allow for compression
   * of diffpaths, as each snake is represented by a single {@link Snake Snake}
   * node and each contiguous series of insertions and deletions is represented
   * by a single {@link DiffNode DiffNodes}.
   *
   * @version $Revision: 1.1 $ $Date: 2003/05/10 18:56:10 $
   * @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a>
   *
   */
  public final class Snake
      extends PathNode
  {
      /**
       * Constructs a snake node.
       *
       * @param the position in the original sequence
       * @param the position in the revised sequence
       * @param prev the previous node in the path.
       */
      public Snake(int i, int j, PathNode prev)
      {
          super(i, j, prev);
      }
  
      /**
       * {@inheritDoc}
       * @return true always
       */
      public boolean isSnake()
      {
          return true;
      }
  
  }
  
  
  1.1                  jakarta-commons-sandbox/jrcs/src/java/org/apache/commons/jrcs/diff/myers/package.html
  
  Index: package.html
  ===================================================================
  <!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN">
  <!--
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2002 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 acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache" and "Apache Software Foundation" and
   *    "Apache Maven" 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",
   *    "Apache Maven", nor may "Apache" appear in their name, 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/>.
   */
   -->
  <html>
    <head>
      <meta name="generator" content=
      "HTML Tidy for Cygwin (vers 1st February 2003), see www.w3.org">
      <title></title>
    </head>
    <body>
      <p>
        The {@link org.apache.maven.jrcs.diff.myers diff.myers} package
        implements  <a href=
        "http://www.cs.arizona.edu/people/gene/">Gene Myers</a>'
        differencing algorithm.
      </p>
      <p>
        Myer's algorithm produces optimum results (minimum diffs), but
        consumes considerably more memory than SimpleDiff, so its not
        suitable for very large files.
        </p>
  @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a>
  @version $Id: package.html,v 1.1 2003/05/10 18:56:10 juanco Exp $
  @see Diff 
  @see org.apache.maven.jrcs.rcs.Archive
    </body>
  </html>
  
  
  

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