/*
 * Copyright (C) 2010, Google Inc. and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

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);
}