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.revwalk.filter;
45
46 import java.io.IOException;
47
48 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
49 import org.eclipse.jgit.errors.MissingObjectException;
50 import org.eclipse.jgit.errors.StopWalkException;
51 import org.eclipse.jgit.internal.JGitText;
52 import org.eclipse.jgit.revwalk.RevCommit;
53 import org.eclipse.jgit.revwalk.RevWalk;
54
55 /**
56 * Selects interesting revisions during walking.
57 * <p>
58 * This is an abstract interface. Applications may implement a subclass, or use
59 * one of the predefined implementations already available within this package.
60 * Filters may be chained together using <code>AndRevFilter</code> and
61 * <code>OrRevFilter</code> to create complex boolean expressions.
62 * <p>
63 * Applications should install the filter on a RevWalk by
64 * {@link RevWalk#setRevFilter(RevFilter)} prior to starting traversal.
65 * <p>
66 * Unless specifically noted otherwise a RevFilter implementation is not thread
67 * safe and may not be shared by different RevWalk instances at the same time.
68 * This restriction allows RevFilter implementations to cache state within their
69 * instances during {@link #include(RevWalk, RevCommit)} if it is beneficial to
70 * their implementation. Deep clones created by {@link #clone()} may be used to
71 * construct a thread-safe copy of an existing filter.
72 *
73 * <p>
74 * <b>Message filters:</b>
75 * <ul>
76 * <li>Author name/email: {@link AuthorRevFilter}</li>
77 * <li>Committer name/email: {@link CommitterRevFilter}</li>
78 * <li>Message body: {@link MessageRevFilter}</li>
79 * </ul>
80 *
81 * <p>
82 * <b>Merge filters:</b>
83 * <ul>
84 * <li>Skip all merges: {@link #NO_MERGES}.</li>
85 * </ul>
86 *
87 * <p>
88 * <b>Boolean modifiers:</b>
89 * <ul>
90 * <li>AND: {@link AndRevFilter}</li>
91 * <li>OR: {@link OrRevFilter}</li>
92 * <li>NOT: {@link NotRevFilter}</li>
93 * </ul>
94 */
95 public abstract class RevFilter {
96 /** Default filter that always returns true (thread safe). */
97 public static final RevFilter ALL = new AllFilter();
98
99 private static final class AllFilter extends RevFilter {
100 @Override
101 public boolean include(final RevWalk walker, final RevCommit c) {
102 return true;
103 }
104
105 @Override
106 public RevFilter clone() {
107 return this;
108 }
109
110 @Override
111 public boolean requiresCommitBody() {
112 return false;
113 }
114
115 @Override
116 public String toString() {
117 return "ALL"; //$NON-NLS-1$
118 }
119 }
120
121 /** Default filter that always returns false (thread safe). */
122 public static final RevFilter NONE = new NoneFilter();
123
124 private static final class NoneFilter extends RevFilter {
125 @Override
126 public boolean include(final RevWalk walker, final RevCommit c) {
127 return false;
128 }
129
130 @Override
131 public RevFilter clone() {
132 return this;
133 }
134
135 @Override
136 public boolean requiresCommitBody() {
137 return false;
138 }
139
140 @Override
141 public String toString() {
142 return "NONE"; //$NON-NLS-1$
143 }
144 }
145
146 /** Excludes commits with more than one parent (thread safe). */
147 public static final RevFilter NO_MERGES = new NoMergesFilter();
148
149 private static final class NoMergesFilter extends RevFilter {
150 @Override
151 public boolean include(final RevWalk walker, final RevCommit c) {
152 return c.getParentCount() < 2;
153 }
154
155 @Override
156 public RevFilter clone() {
157 return this;
158 }
159
160 @Override
161 public boolean requiresCommitBody() {
162 return false;
163 }
164
165 @Override
166 public String toString() {
167 return "NO_MERGES"; //$NON-NLS-1$
168 }
169 }
170
171 /**
172 * Selects only merge bases of the starting points (thread safe).
173 * <p>
174 * This is a special case filter that cannot be combined with any other
175 * filter. Its include method always throws an exception as context
176 * information beyond the arguments is necessary to determine if the
177 * supplied commit is a merge base.
178 */
179 public static final RevFilter MERGE_BASE = new MergeBaseFilter();
180
181 private static final class MergeBaseFilter extends RevFilter {
182 @Override
183 public boolean include(final RevWalk walker, final RevCommit c) {
184 throw new UnsupportedOperationException(JGitText.get().cannotBeCombined);
185 }
186
187 @Override
188 public RevFilter clone() {
189 return this;
190 }
191
192 @Override
193 public boolean requiresCommitBody() {
194 return false;
195 }
196
197 @Override
198 public String toString() {
199 return "MERGE_BASE"; //$NON-NLS-1$
200 }
201 }
202
203 /**
204 * Create a new filter that does the opposite of this filter.
205 *
206 * @return a new filter that includes commits this filter rejects.
207 */
208 public RevFilter negate() {
209 return NotRevFilter.create(this);
210 }
211
212 /** @return true if the filter needs the commit body to be parsed. */
213 public boolean requiresCommitBody() {
214 // Assume true to be backward compatible with prior behavior.
215 return true;
216 }
217
218 /**
219 * Determine if the supplied commit should be included in results.
220 *
221 * @param walker
222 * the active walker this filter is being invoked from within.
223 * @param cmit
224 * the commit currently being tested. The commit has been parsed
225 * and its body is available for inspection only if the filter
226 * returns true from {@link #requiresCommitBody()}.
227 * @return true to include this commit in the results; false to have this
228 * commit be omitted entirely from the results.
229 * @throws StopWalkException
230 * the filter knows for certain that no additional commits can
231 * ever match, and the current commit doesn't match either. The
232 * walk is halted and no more results are provided.
233 * @throws MissingObjectException
234 * an object the filter needs to consult to determine its answer
235 * does not exist in the Git repository the walker is operating
236 * on. Filtering this commit is impossible without the object.
237 * @throws IncorrectObjectTypeException
238 * an object the filter needed to consult was not of the
239 * expected object type. This usually indicates a corrupt
240 * repository, as an object link is referencing the wrong type.
241 * @throws IOException
242 * a loose object or pack file could not be read to obtain data
243 * necessary for the filter to make its decision.
244 */
245 public abstract boolean include(RevWalk walker, RevCommit cmit)
246 throws StopWalkException, MissingObjectException,
247 IncorrectObjectTypeException, IOException;
248
249 /**
250 * Clone this revision filter, including its parameters.
251 * <p>
252 * This is a deep clone. If this filter embeds objects or other filters it
253 * must also clone those, to ensure the instances do not share mutable data.
254 *
255 * @return another copy of this filter, suitable for another thread.
256 */
257 public abstract RevFilter clone();
258
259 @Override
260 public String toString() {
261 String n = getClass().getName();
262 int lastDot = n.lastIndexOf('.');
263 if (lastDot >= 0) {
264 n = n.substring(lastDot + 1);
265 }
266 return n.replace('$', '.');
267 }
268 }