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1   /*
2    * Copyright (C) 2010, Google Inc.
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  
44  package org.eclipse.jgit.revwalk;
45  
46  import java.io.IOException;
47  
48  import org.eclipse.jgit.diff.DiffConfig;
49  import org.eclipse.jgit.errors.IncorrectObjectTypeException;
50  import org.eclipse.jgit.errors.MissingObjectException;
51  import org.eclipse.jgit.treewalk.TreeWalk;
52  import org.eclipse.jgit.treewalk.filter.PathFilter;
53  import org.eclipse.jgit.treewalk.filter.TreeFilter;
54  
55  /**
56   * Updates the internal path filter to follow copy/renames.
57   * <p>
58   * This is a special filter that performs {@code AND(path, ANY_DIFF)}, but also
59   * triggers rename detection so that the path node is updated to include a prior
60   * file name as the RevWalk traverses history.
61   *
62   * The renames found will be reported to a {@link RenameCallback} if one is set.
63   * <p>
64   * Results with this filter are unpredictable if the path being followed is a
65   * subdirectory.
66   */
67  public class FollowFilter extends TreeFilter {
68  	/**
69  	 * Create a new tree filter for a user supplied path.
70  	 * <p>
71  	 * Path strings are relative to the root of the repository. If the user's
72  	 * input should be assumed relative to a subdirectory of the repository the
73  	 * caller must prepend the subdirectory's path prior to creating the filter.
74  	 * <p>
75  	 * Path strings use '/' to delimit directories on all platforms.
76  	 *
77  	 * @param path
78  	 *            the path to filter on. Must not be the empty string. All
79  	 *            trailing '/' characters will be trimmed before string's length
80  	 *            is checked or is used as part of the constructed filter.
81  	 * @param cfg
82  	 *            diff config specifying rename detection options.
83  	 * @return a new filter for the requested path.
84  	 * @throws IllegalArgumentException
85  	 *             the path supplied was the empty string.
86  	 * @since 3.0
87  	 */
88  	public static FollowFilter create(String path, DiffConfig cfg) {
89  		return new FollowFilter(PathFilter.create(path), cfg);
90  	}
91  
92  	private final PathFilter path;
93  	final DiffConfig cfg;
94  
95  	private RenameCallback renameCallback;
96  
97  	FollowFilter(final PathFilter path, final DiffConfig cfg) {
98  		this.path = path;
99  		this.cfg = cfg;
100 	}
101 
102 	/** @return the path this filter matches. */
103 	public String getPath() {
104 		return path.getPath();
105 	}
106 
107 	@Override
108 	public boolean include(final TreeWalk walker)
109 			throws MissingObjectException, IncorrectObjectTypeException,
110 			IOException {
111 		return path.include(walker) && ANY_DIFF.include(walker);
112 	}
113 
114 	@Override
115 	public boolean shouldBeRecursive() {
116 		return path.shouldBeRecursive() || ANY_DIFF.shouldBeRecursive();
117 	}
118 
119 	@Override
120 	public TreeFilter clone() {
121 		return new FollowFilter(path.clone(), cfg);
122 	}
123 
124 	@SuppressWarnings("nls")
125 	@Override
126 	public String toString() {
127 		return "(FOLLOW(" + path.toString() + ")" //
128 				+ " AND " //
129 				+ ANY_DIFF.toString() + ")";
130 	}
131 
132 	/**
133 	 * @return the callback to which renames are reported, or <code>null</code>
134 	 *         if none
135 	 */
136 	public RenameCallback getRenameCallback() {
137 		return renameCallback;
138 	}
139 
140 	/**
141 	 * Sets the callback to which renames shall be reported.
142 	 *
143 	 * @param callback
144 	 *            the callback to use
145 	 */
146 	public void setRenameCallback(RenameCallback callback) {
147 		renameCallback = callback;
148 	}
149 }