http://www.eclipse.org/jgit//org.eclipse.jgit: Repository access and algorithms (Eclipse JGit Project)
  • Eclipse Distribution License (New BSD License)
  • Andrey Loskutov
  • Christian Halstrick
  • Dave Borowitz
  • David Pursehouse
  • Gunnar Wagenknecht
  • Jonathan Nieder
  • Jonathan Tan
  • Matthias Sohn
  • Sasa Zivkov
  • Terry Parker
  • Thomas Wolf 
/*
 * Copyright (C) 2010, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - 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.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * 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.
 */

package org.eclipse.jgit.diff;


Compares two sequences primarily based upon hash codes.

/**
 * Compares two sequences primarily based upon hash codes.
 */
public abstract class LowLevelDiffAlgorithm extends DiffAlgorithm {
	
{@inheritDoc} 
/** {@inheritDoc} */
	@Override
	public <S extends Sequence> EditList diffNonCommon(
			SequenceComparator<? super S> cmp, S a, S b) {
		HashedSequencePair<S> p = new HashedSequencePair<>(cmp, a, b);
		HashedSequenceComparator<S> hc = p.getComparator();
		HashedSequence<S> ha = p.getA();
		HashedSequence<S> hb = p.getB();
		p = null;

		EditList res = new EditList();
		Edit region = new Edit(0, a.size(), 0, b.size());
		diffNonCommon(res, hc, ha, hb, region);
		return res;
	}

	
Compare two sequences and identify a list of edits between them. This method should be invoked only after the two sequences have been proven to have no common starting or ending elements. The expected elimination of common starting and ending elements is automatically performed by the DiffAlgorithm.diff(SequenceComparator<? super Sequence>, Sequence, Sequence) method, which invokes this method using Subsequences. 
Params:
  • edits – 
           result list to append the region's edits onto.
  • cmp – 
           the comparator supplying the element equivalence function.
  • a –  the first (also known as old or pre-image) sequence. Edits returned by this algorithm will reference indexes using the 'A' side: Edit.getBeginA(), Edit.getEndA().
  • b –  the second (also known as new or post-image) sequence. Edits returned by this algorithm will reference indexes using the 'B' side: Edit.getBeginB(), Edit.getEndB().
  • region – 
           the region being compared within the two sequences.
/**
	 * Compare two sequences and identify a list of edits between them.
	 *
	 * This method should be invoked only after the two sequences have been
	 * proven to have no common starting or ending elements. The expected
	 * elimination of common starting and ending elements is automatically
	 * performed by the {@link #diff(SequenceComparator, Sequence, Sequence)}
	 * method, which invokes this method using
	 * {@link org.eclipse.jgit.diff.Subsequence}s.
	 *
	 * @param edits
	 *            result list to append the region's edits onto.
	 * @param cmp
	 *            the comparator supplying the element equivalence function.
	 * @param a
	 *            the first (also known as old or pre-image) sequence. Edits
	 *            returned by this algorithm will reference indexes using the
	 *            'A' side: {@link org.eclipse.jgit.diff.Edit#getBeginA()},
	 *            {@link org.eclipse.jgit.diff.Edit#getEndA()}.
	 * @param b
	 *            the second (also known as new or post-image) sequence. Edits
	 *            returned by this algorithm will reference indexes using the
	 *            'B' side: {@link org.eclipse.jgit.diff.Edit#getBeginB()},
	 *            {@link org.eclipse.jgit.diff.Edit#getEndB()}.
	 * @param region
	 *            the region being compared within the two sequences.
	 */
	public abstract <S extends Sequence> void diffNonCommon(EditList edits,
			HashedSequenceComparator<S> cmp, HashedSequence<S> a,
			HashedSequence<S> b, Edit region);
}