• Home
• org.jmeld
• jmeld
• 2.1
• source code
• Chunk.java

×

Project download

Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $

You can buy this project and download/modify it how often you want.

org.apache.commons.jrcs.diff.Chunk Maven / Gradle / Ivy

/*
 * ====================================================================
 *
 * 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 [email protected].
 *
 * 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
 * .
 *
 */
package org.apache.commons.jrcs.diff;

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

/**
 * Holds a information about a parrt of the text involved in
 * a differencing or patching operation.
 *
 * @version $Id: Chunk.java,v 1.3 2003/05/06 14:59:12 juanco Exp $
 * @author Juanco Anez
 * @see Diff
 * @see Delta
 */
public class Chunk
    extends org.apache.commons.jrcs.util.ToString
{
  protected int anchor;
  protected int count;
  protected List chunk;

  /**
   * Creates a chunk that doesn't copy the original text.
   * @param pos the start position in the text.
   * @param count the size of the chunk.
   */
  public Chunk(int pos, int count)
  {
    this.anchor = pos;
    this.count = (count >= 0 ? count : 0);
  }

  /**
   * Creates a chunk and saves a copy the original chunk's text.
   * @param iseq the original text.
   * @param pos the start position in the text.
   * @param count the size of the chunk.
   */
  public Chunk(Object[] iseq, int pos, int count)
  {
    this(pos, count);
    chunk = slice(iseq, pos, count);
  }

  /**
   * Creates a chunk that will be displaced in the resulting text,
   * and saves a copy the original chunk's text.
   * @param iseq the original text.
   * @param pos the start position in the text.
   * @param count the size of the chunk.
   * @param offset the position the chunk should have in the resulting text.
   */
  public Chunk(Object[] iseq, int pos, int count, int offset)
  {
    this(offset, count);
    chunk = slice(iseq, pos, count);
  }

  /**
   * Creates a chunk and saves a copy the original chunk's text.
   * @param iseq the original text.
   * @param pos the start position in the text.
   * @param count the size of the chunk.
   */
  public Chunk(List iseq, int pos, int count)
  {
    this(pos, count);
    chunk = slice(iseq, pos, count);
  }

  /**
   * Creates a chunk that will be displaced in the resulting text,
   * and saves a copy the original chunk's text.
   * @param iseq the original text.
   * @param pos the start position in the text.
   * @param count the size of the chunk.
   * @param offset the position the chunk should have in the resulting text.
   */
  public Chunk(List iseq, int pos, int count, int offset)
  {
    this(offset, count);
    chunk = slice(iseq, pos, count);
  }

  /**
   * Returns the anchor position of the chunk.
   * @return the anchor position.
   */
  public int anchor()
  {
    return anchor;
  }

  /**
   * Returns the size of the chunk.
   * @return the size.
   */
  public int size()
  {
    return count;
  }

  /**
   * Returns the index of the first line of the chunk.
   */
  public int first()
  {
    return anchor();
  }

  /**
   * Returns the index of the last line of the chunk.
   */
  public int last()
  {
    return anchor() + size() - 1;
  }

  /**
   * Returns the from index of the chunk in RCS terms.
   */
  public int rcsfrom()
  {
    return anchor + 1;
  }

  /**
   * Returns the to index of the chunk in RCS terms.
   */
  public int rcsto()
  {
    return anchor + count;
  }

  /**
   * Returns the text saved for this chunk.
   * @return the text.
   */
  public List chunk()
  {
    return chunk;
  }

  /**
   * Verifies that this chunk's saved text matches the corresponding
   * text in the given sequence.
   * @param target the sequence to verify against.
   * @return true if the texts match.
   */
  public boolean verify(List target)
  {
    if (chunk == null)
    {
      return true;
    }

    if (last() > target.size())
    {
      return false;
    }

    for (int i = 0; i < count; i++)
    {
      if (!target.get(anchor + i).equals(chunk.get(i)))
      {
        return false;
      }
    }

    return true;
  }

  /**
   * Delete this chunk from he given text.
   * @param target the text to delete from.
   */
  public void applyDelete(List target)
  {
    for (int i = last(); i >= first(); i--)
    {
      target.remove(i);
    }
  }

  /**
   * Add the text of this chunk to the target at the given position.
   * @param start where to add the text.
   * @param target the text to add to.
   */
  public void applyAdd(int start, List target)
  {
    Iterator i = chunk.iterator();

    while (i.hasNext())
    {
      target.add(start++, i.next());
    }
  }

  /**
   * Provide a string image of the chunk using the an empty prefix and
   * postfix.
   */
  public void toString(StringBuffer s)
  {
    toString(s, "", "");
  }

  /**
   * Provide a string image of the chunk using the given prefix and
   * postfix.
   * @param s where the string image should be appended.
   * @param prefix the text thatshould prefix each line.
   * @param postfix the text that should end each line.
   */
  public StringBuffer toString(StringBuffer s, String prefix, String postfix)
  {
    if (chunk != null)
    {
      Iterator i = chunk.iterator();

      while (i.hasNext())
      {
        s.append(prefix);
        s.append(i.next());
        s.append(postfix);
      }
    }

    return s;
  }

  /**
   * Retreives the specified part from a {@link List List}.
   * @param seq the list to retreive a slice from.
   * @param pos the start position.
   * @param count the number of items in the slice.
   * @return a {@link List List} containing the specified items.
   */
  public static List slice(List seq, int pos, int count)
  {
    if (count <= 0)
    {
      return new ArrayList(seq.subList(pos, pos));
    }
    else
    {
      return new ArrayList(seq.subList(pos, pos + count));
    }
  }

  /**
   * Retrieves a slice from an {@link Object Object} array.
   * @param seq the list to retreive a slice from.
   * @param pos the start position.
   * @param count the number of items in the slice.
   * @return a {@link List List} containing the specified items.
   */
  public static List slice(Object[] seq, int pos, int count)
  {
    return slice(Arrays.asList(seq), pos, count);
  }

  /**
   * Provide a string representation of the numeric range of this chunk.
   */
  public String rangeString()
  {
    StringBuffer result = new StringBuffer();

    rangeString(result);
    return result.toString();
  }

  /**
   * Provide a string representation of the numeric range of this chunk.
   * @param s where the string representation should be appended.
   */
  public void rangeString(StringBuffer s)
  {
    rangeString(s, ",");
  }

  /**
   * Provide a string representation of the numeric range of this chunk.
   * @param s where the string representation should be appended.
   * @param separ what to use as line separator.
   */
  public void rangeString(StringBuffer s, String separ)
  {
    if (size() <= 1)
    {
      s.append(Integer.toString(rcsfrom()));
    }
    else
    {
      s.append(Integer.toString(rcsfrom()));
      s.append(separ);
      s.append(Integer.toString(rcsto()));
    }
  }
}