001/*
002 * (C) Copyright 2006-2007 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 *
019 * $Id$
020 */
021
022package org.nuxeo.runtime.deployment.preprocessor.install.filters;
023
024import org.nuxeo.common.utils.Path;
025import org.nuxeo.common.utils.PathFilter;
026
027/**
028 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
029 */
030public abstract class AbstractFilter implements PathFilter {
031
032    protected final Path pattern;
033
034    protected AbstractFilter(Path pattern) {
035        this.pattern = pattern;
036    }
037
038    public boolean accept(Path path, boolean defaultPolicy) {
039        // path should be in canonical form
040        boolean match = segmentsMatch(pattern, path);
041        return match ? !defaultPolicy : defaultPolicy;
042    }
043
044    protected static boolean segmentsMatch(Path pattern, Path path) {
045        int patternLen = pattern.segmentCount();
046        int k = 0;
047        for (int i = 0, len = path.segmentCount(); i < len; i++) {
048            if (k >= patternLen) {
049                return false;
050            }
051            String segPattern = pattern.segment(k);
052            String segment = path.segment(i);
053            if (segPattern.equals("**")) {
054                k++;
055                if (k == patternLen) {
056                    return true;
057                }
058                // skip non matching segments
059                String match = pattern.segment(k);
060                for (; i < len; i++) {
061                    if (segmentMatch(match, path.segment(i))) {
062                        k++;
063                        break;
064                    }
065                }
066            } else if (segmentMatch(segPattern, segment)) {
067                k++;
068            } else {
069                return false;
070            }
071        }
072        return k >= patternLen;
073    }
074
075    public static boolean segmentMatch(String pattern, String segment) {
076        if (pattern.equals("*")) {
077            return true;
078        }
079        int p = pattern.indexOf('*');
080        if (p == -1) {
081            return pattern.equals(segment);
082        }
083        if (p == 0) {
084            if (!segment.endsWith(pattern.substring(1))) {
085                return false;
086            }
087        } else if (p == pattern.length() - 1) {
088            if (!segment.startsWith(pattern.substring(0, p))) {
089                return false;
090            }
091        } else {
092            String prefix = pattern.substring(0, p);
093            String suffix = pattern.substring(p + 1);
094            if (!segment.startsWith(prefix) || !segment.endsWith(suffix)) {
095                return false;
096            }
097        }
098        return true;
099    }
100
101}