jgit/org.eclipse.jgit/src/org/eclipse/jgit/ignore/internal/LeadingAsteriskMatcher.java

/*
 * Copyright (C) 2014, Andrey Loskutov <loskutov@gmx.de>
 * 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
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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package org.eclipse.jgit.ignore.internal;

/**
 * Matcher for simple regex patterns starting with an asterisk, e.g. "*.tmp"
 *
 * @since 3.6
 */
public class LeadingAsteriskMatcher extends NameMatcher {

	LeadingAsteriskMatcher(String pattern, Character pathSeparator, boolean dirOnly) {
		super(pattern, pathSeparator, dirOnly, true);

		if (subPattern.charAt(0) != '*')
			throw new IllegalArgumentException(
					"Pattern must have leading asterisk: " + pattern); //$NON-NLS-1$
	}

	public boolean matches(String segment, int startIncl, int endExcl,
			boolean assumeDirectory) {
		// faster local access, same as in string.indexOf()
		String s = subPattern;

		// we don't need to count '*' character itself
		int subLength = s.length() - 1;
		// simple /*/ pattern
		if (subLength == 0)
			return true;

		if (subLength > (endExcl - startIncl))
			return false;

		for (int i = subLength, j = endExcl - 1; i > 0; i--, j--) {
			char c1 = s.charAt(i);
			char c2 = segment.charAt(j);
			if (c1 != c2)
				return false;
		}
		return true;
	}

}