1 /*
2 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
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.treewalk.filter;
45
46 import java.io.IOException;
47
48 import org.eclipse.jgit.dircache.DirCacheIterator;
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.WorkingTreeIterator;
53
54 /**
55 * Selects interesting tree entries during walking.
56 * <p>
57 * This is an abstract interface. Applications may implement a subclass, or use
58 * one of the predefined implementations already available within this package.
59 * <p>
60 * Unless specifically noted otherwise a TreeFilter implementation is not thread
61 * safe and may not be shared by different TreeWalk instances at the same time.
62 * This restriction allows TreeFilter implementations to cache state within
63 * their instances during {@link #include(TreeWalk)} if it is beneficial to
64 * their implementation. Deep clones created by {@link #clone()} may be used to
65 * construct a thread-safe copy of an existing filter.
66 *
67 * <p>
68 * <b>Path filters:</b>
69 * <ul>
70 * <li>Matching pathname:
71 * {@link org.eclipse.jgit.treewalk.filter.PathFilter}</li>
72 * </ul>
73 *
74 * <p>
75 * <b>Difference filters:</b>
76 * <ul>
77 * <li>Only select differences: {@link #ANY_DIFF}.</li>
78 * </ul>
79 *
80 * <p>
81 * <b>Boolean modifiers:</b>
82 * <ul>
83 * <li>AND: {@link org.eclipse.jgit.treewalk.filter.AndTreeFilter}</li>
84 * <li>OR: {@link org.eclipse.jgit.treewalk.filter.OrTreeFilter}</li>
85 * <li>NOT: {@link org.eclipse.jgit.treewalk.filter.NotTreeFilter}</li>
86 * </ul>
87 */
88 public abstract class TreeFilter {
89 /** Selects all tree entries. */
90 public static final TreeFilter ALL = new AllFilter();
91
92 private static final class AllFilter extends TreeFilter {
93 @Override
94 public boolean include(TreeWalk walker) {
95 return true;
96 }
97
98 @Override
99 public boolean shouldBeRecursive() {
100 return false;
101 }
102
103 @Override
104 public TreeFilter clone() {
105 return this;
106 }
107
108 @Override
109 public String toString() {
110 return "ALL"; //$NON-NLS-1$
111 }
112 }
113
114 /**
115 * Selects only tree entries which differ between at least 2 trees.
116 * <p>
117 * This filter also prevents a TreeWalk from recursing into a subtree if all
118 * parent trees have the identical subtree at the same path. This
119 * dramatically improves walk performance as only the changed subtrees are
120 * entered into.
121 * <p>
122 * If this filter is applied to a walker with only one tree it behaves like
123 * {@link #ALL}, or as though the walker was matching a virtual empty tree
124 * against the single tree it was actually given. Applications may wish to
125 * treat such a difference as "all names added".
126 * <p>
127 * When comparing {@link WorkingTreeIterator} and {@link DirCacheIterator}
128 * applications should use {@link IndexDiffFilter}.
129 */
130 public static final TreeFilter ANY_DIFF = new AnyDiffFilter();
131
132 private static final class AnyDiffFilter extends TreeFilter {
133 private static final int baseTree = 0;
134
135 @Override
136 public boolean include(TreeWalk walker) {
137 final int n = walker.getTreeCount();
138 if (n == 1) // Assume they meant difference to empty tree.
139 return true;
140
141 final int m = walker.getRawMode(baseTree);
142 for (int i = 1; i < n; i++)
143 if (walker.getRawMode(i) != m || !walker.idEqual(i, baseTree))
144 return true;
145 return false;
146 }
147
148 @Override
149 public boolean shouldBeRecursive() {
150 return false;
151 }
152
153 @Override
154 public TreeFilter clone() {
155 return this;
156 }
157
158 @Override
159 public String toString() {
160 return "ANY_DIFF"; //$NON-NLS-1$
161 }
162 }
163
164 /**
165 * Create a new filter that does the opposite of this filter.
166 *
167 * @return a new filter that includes tree entries this filter rejects.
168 */
169 public TreeFilter negate() {
170 return NotTreeFilter.create(this);
171 }
172
173 /**
174 * Determine if the current entry is interesting to report.
175 * <p>
176 * This method is consulted for subtree entries even if
177 * {@link org.eclipse.jgit.treewalk.TreeWalk#isRecursive()} is enabled. The
178 * consultation allows the filter to bypass subtree recursion on a
179 * case-by-case basis, even when recursion is enabled at the application
180 * level.
181 *
182 * @param walker
183 * the walker the filter needs to examine.
184 * @return true if the current entry should be seen by the application;
185 * false to hide the entry.
186 * @throws org.eclipse.jgit.errors.MissingObjectException
187 * an object the filter needs to consult to determine its answer
188 * does not exist in the Git repository the walker is operating
189 * on. Filtering this current walker entry is impossible without
190 * the object.
191 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
192 * an object the filter needed to consult was not of the
193 * expected object type. This usually indicates a corrupt
194 * repository, as an object link is referencing the wrong type.
195 * @throws java.io.IOException
196 * a loose object or pack file could not be read to obtain data
197 * necessary for the filter to make its decision.
198 */
199 public abstract boolean include(TreeWalk walker)
200 throws MissingObjectException, IncorrectObjectTypeException,
201 IOException;
202
203 /**
204 * Determine if the current entry is a parent, a match, or no match.
205 * <p>
206 * This method extends the result returned by {@link #include(TreeWalk)}
207 * with a third option (-1), splitting the value true. This gives the
208 * application a possibility to distinguish between an exact match and the
209 * case when a subtree to the current entry might be a match.
210 *
211 * @param walker
212 * the walker the filter needs to examine.
213 * @return -1 if the current entry is a parent of the filter but no exact
214 * match has been made; 0 if the current entry should be seen by the
215 * application; 1 if it should be hidden.
216 * @throws org.eclipse.jgit.errors.MissingObjectException
217 * as thrown by {@link #include(TreeWalk)}
218 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
219 * as thrown by {@link #include(TreeWalk)}
220 * @throws java.io.IOException
221 * as thrown by {@link #include(TreeWalk)}
222 * @since 4.7
223 */
224 public int matchFilter(TreeWalk walker)
225 throws MissingObjectException, IncorrectObjectTypeException,
226 IOException
227 {
228 return include(walker) ? 0 : 1;
229 }
230
231 /**
232 * Does this tree filter require a recursive walk to match everything?
233 * <p>
234 * If this tree filter is matching on full entry path names and its pattern
235 * is looking for a '/' then the filter would require a recursive TreeWalk
236 * to accurately make its decisions. The walker is not required to enable
237 * recursive behavior for any particular filter, this is only a hint.
238 *
239 * @return true if the filter would like to have the walker recurse into
240 * subtrees to make sure it matches everything correctly; false if
241 * the filter does not require entering subtrees.
242 */
243 public abstract boolean shouldBeRecursive();
244
245 /**
246 * {@inheritDoc}
247 *
248 * Clone this tree filter, including its parameters.
249 * <p>
250 * This is a deep clone. If this filter embeds objects or other filters it
251 * must also clone those, to ensure the instances do not share mutable data.
252 */
253 @Override
254 public abstract TreeFilter clone();
255
256 /** {@inheritDoc} */
257 @Override
258 public String toString() {
259 String n = getClass().getName();
260 int lastDot = n.lastIndexOf('.');
261 if (lastDot >= 0) {
262 n = n.substring(lastDot + 1);
263 }
264 return n.replace('$', '.');
265 }
266 }