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1   /*
2    * Copyright (C) 2014, Andrey Loskutov <loskutov@gmx.de>
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  package org.eclipse.jgit.ignore.internal;
44  
45  import static org.eclipse.jgit.ignore.internal.Strings.checkWildCards;
46  import static org.eclipse.jgit.ignore.internal.Strings.count;
47  import static org.eclipse.jgit.ignore.internal.Strings.getPathSeparator;
48  import static org.eclipse.jgit.ignore.internal.Strings.isWildCard;
49  import static org.eclipse.jgit.ignore.internal.Strings.split;
50  
51  import java.util.ArrayList;
52  import java.util.List;
53  
54  import org.eclipse.jgit.errors.InvalidPatternException;
55  import org.eclipse.jgit.ignore.FastIgnoreRule;
56  import org.eclipse.jgit.ignore.internal.Strings.PatternState;
57  
58  /**
59   * Matcher built by patterns consists of multiple path segments.
60   * <p>
61   * This class is immutable and thread safe.
62   */
63  public class PathMatcher extends AbstractMatcher {
64  
65  	private static final WildMatcher WILD = WildMatcher.INSTANCE;
66  
67  	private final List<IMatcher> matchers;
68  
69  	private final char slash;
70  
71  	private boolean beginning;
72  
73  	PathMatcher(String pattern, Character pathSeparator, boolean dirOnly)
74  			throws InvalidPatternException {
75  		super(pattern, dirOnly);
76  		slash = getPathSeparator(pathSeparator);
77  		beginning = pattern.indexOf(slash) == 0;
78  		if (isSimplePathWithSegments(pattern))
79  			matchers = null;
80  		else
81  			matchers = createMatchers(split(pattern, slash), pathSeparator,
82  					dirOnly);
83  	}
84  
85  	private boolean isSimplePathWithSegments(String path) {
86  		return !isWildCard(path) && path.indexOf('\\') < 0
87  				&& count(path, slash, true) > 0;
88  	}
89  
90  	static private List<IMatcher> createMatchers(List<String> segments,
91  			Character pathSeparator, boolean dirOnly)
92  			throws InvalidPatternException {
93  		List<IMatcher> matchers = new ArrayList<>(segments.size());
94  		for (int i = 0; i < segments.size(); i++) {
95  			String segment = segments.get(i);
96  			IMatcher matcher = createNameMatcher0(segment, pathSeparator,
97  					dirOnly);
98  			if (matcher == WILD && i > 0
99  					&& matchers.get(matchers.size() - 1) == WILD)
100 				// collapse wildmatchers **/** is same as **
101 				continue;
102 			matchers.add(matcher);
103 		}
104 		return matchers;
105 	}
106 
107 	/**
108 	 *
109 	 * @param pattern
110 	 * @param pathSeparator
111 	 *            if this parameter isn't null then this character will not
112 	 *            match at wildcards(* and ? are wildcards).
113 	 * @param dirOnly
114 	 * @return never null
115 	 * @throws InvalidPatternException
116 	 */
117 	public static IMatcher createPathMatcher(String pattern,
118 			Character pathSeparator, boolean dirOnly)
119 			throws InvalidPatternException {
120 		pattern = trim(pattern);
121 		char slash = Strings.getPathSeparator(pathSeparator);
122 		// ignore possible leading and trailing slash
123 		int slashIdx = pattern.indexOf(slash, 1);
124 		if (slashIdx > 0 && slashIdx < pattern.length() - 1)
125 			return new PathMatcher(pattern, pathSeparator, dirOnly);
126 		return createNameMatcher0(pattern, pathSeparator, dirOnly);
127 	}
128 
129 	/**
130 	 * Trim trailing spaces, unless they are escaped with backslash, see
131 	 * https://www.kernel.org/pub/software/scm/git/docs/gitignore.html
132 	 *
133 	 * @param pattern
134 	 *            non null
135 	 * @return trimmed pattern
136 	 */
137 	private static String trim(String pattern) {
138 		while (pattern.length() > 0
139 				&& pattern.charAt(pattern.length() - 1) == ' ') {
140 			if (pattern.length() > 1
141 					&& pattern.charAt(pattern.length() - 2) == '\\') {
142 				// last space was escaped by backslash: remove backslash and
143 				// keep space
144 				pattern = pattern.substring(0, pattern.length() - 2) + " "; //$NON-NLS-1$
145 				return pattern;
146 			}
147 			pattern = pattern.substring(0, pattern.length() - 1);
148 		}
149 		return pattern;
150 	}
151 
152 	private static IMatcher createNameMatcher0(String segment,
153 			Character pathSeparator, boolean dirOnly)
154 			throws InvalidPatternException {
155 		// check if we see /** or ** segments => double star pattern
156 		if (WildMatcher.WILDMATCH.equals(segment)
157 				|| WildMatcher.WILDMATCH2.equals(segment))
158 			return WILD;
159 
160 		PatternState state = checkWildCards(segment);
161 		switch (state) {
162 		case LEADING_ASTERISK_ONLY:
163 			return new LeadingAsteriskMatcher(segment, pathSeparator, dirOnly);
164 		case TRAILING_ASTERISK_ONLY:
165 			return new TrailingAsteriskMatcher(segment, pathSeparator, dirOnly);
166 		case COMPLEX:
167 			return new WildCardMatcher(segment, pathSeparator, dirOnly);
168 		default:
169 			return new NameMatcher(segment, pathSeparator, dirOnly, true);
170 		}
171 	}
172 
173 	@Override
174 	public boolean matches(String path, boolean assumeDirectory) {
175 		if (matchers == null)
176 			return simpleMatch(path, assumeDirectory);
177 		return iterate(path, 0, path.length(), assumeDirectory);
178 	}
179 
180 	/*
181 	 * Stupid but fast string comparison: the case where we don't have to match
182 	 * wildcards or single segments (mean: this is multi-segment path which must
183 	 * be at the beginning of the another string)
184 	 */
185 	private boolean simpleMatch(String path, boolean assumeDirectory) {
186 		boolean hasSlash = path.indexOf(slash) == 0;
187 		if (beginning && !hasSlash)
188 			path = slash + path;
189 
190 		if (!beginning && hasSlash)
191 			path = path.substring(1);
192 
193 		if (path.equals(pattern))
194 			// Exact match
195 			if (dirOnly && !assumeDirectory)
196 				// Directory expectations not met
197 				return false;
198 			else
199 				// Directory expectations met
200 				return true;
201 
202 		/*
203 		 * Add slashes for startsWith check. This avoids matching e.g.
204 		 * "/src/new" to /src/newfile" but allows "/src/new" to match
205 		 * "/src/new/newfile", as is the git standard
206 		 */
207 		if (path.startsWith(pattern + FastIgnoreRule.PATH_SEPARATOR))
208 			return true;
209 
210 		return false;
211 	}
212 
213 	@Override
214 	public boolean matches(String segment, int startIncl, int endExcl,
215 			boolean assumeDirectory) {
216 		throw new UnsupportedOperationException(
217 				"Path matcher works only on entire paths"); //$NON-NLS-1$
218 	}
219 
220 	boolean iterate(final String path, final int startIncl, final int endExcl,
221 			boolean assumeDirectory) {
222 		int matcher = 0;
223 		int right = startIncl;
224 		boolean match = false;
225 		int lastWildmatch = -1;
226 		while (true) {
227 			int left = right;
228 			right = path.indexOf(slash, right);
229 			if (right == -1) {
230 				if (left < endExcl)
231 					match = matches(matcher, path, left, endExcl,
232 							assumeDirectory);
233 				if (match) {
234 					if (matcher == matchers.size() - 2
235 							&& matchers.get(matcher + 1) == WILD)
236 						// ** can match *nothing*: a/b/** match also a/b
237 						return true;
238 					if (matcher < matchers.size() - 1
239 							&& matchers.get(matcher) == WILD) {
240 						// ** can match *nothing*: a/**/b match also a/b
241 						matcher++;
242 						match = matches(matcher, path, left, endExcl,
243 								assumeDirectory);
244 					} else if (dirOnly && !assumeDirectory)
245 						// Directory expectations not met
246 						return false;
247 				}
248 				return match && matcher + 1 == matchers.size();
249 			}
250 			if (right - left > 0)
251 				match = matches(matcher, path, left, right, assumeDirectory);
252 			else {
253 				// path starts with slash???
254 				right++;
255 				continue;
256 			}
257 			if (match) {
258 				if (matchers.get(matcher) == WILD) {
259 					lastWildmatch = matcher;
260 					// ** can match *nothing*: a/**/b match also a/b
261 					right = left - 1;
262 				}
263 				matcher++;
264 				if (matcher == matchers.size())
265 					return true;
266 			} else if (lastWildmatch != -1)
267 				matcher = lastWildmatch + 1;
268 			else
269 				return false;
270 			right++;
271 		}
272 	}
273 
274 	boolean matches(int matcherIdx, String path, int startIncl, int endExcl,
275 			boolean assumeDirectory) {
276 		IMatcher matcher = matchers.get(matcherIdx);
277 		return matcher.matches(path, startIncl, endExcl, assumeDirectory);
278 	}
279 }