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
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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package org.eclipse.jgit.ignore.internal;

/**
 * Matcher for simple regex patterns starting with an asterisk, e.g. "*.tmp"
 */
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); //$NON-NLS-1$
    }

    /** {@inheritDoc} */
    @Override
    public boolean matches(String segment, int startIncl, int endExcl) {
        // 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;
    }

}