1 /*
2 * Copyright (C) 2008-2009, Google Inc.
3 * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
4 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
5 * and other copyright owners as documented in the project's IP log.
6 *
7 * This program and the accompanying materials are made available
8 * under the terms of the Eclipse Distribution License v1.0 which
9 * accompanies this distribution, is reproduced below, and is
10 * available at http://www.eclipse.org/org/documents/edl-v10.php
11 *
12 * All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or
15 * without modification, are permitted provided that the following
16 * conditions are met:
17 *
18 * - Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 *
21 * - Redistributions in binary form must reproduce the above
22 * copyright notice, this list of conditions and the following
23 * disclaimer in the documentation and/or other materials provided
24 * with the distribution.
25 *
26 * - Neither the name of the Eclipse Foundation, Inc. nor the
27 * names of its contributors may be used to endorse or promote
28 * products derived from this software without specific prior
29 * written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
32 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
33 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
34 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
36 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
37 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
38 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
39 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
40 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
43 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 */
45
46 package org.eclipse.jgit.revwalk;
47
48 import static java.nio.charset.StandardCharsets.UTF_8;
49
50 import java.io.IOException;
51 import java.nio.charset.Charset;
52 import java.nio.charset.IllegalCharsetNameException;
53 import java.nio.charset.UnsupportedCharsetException;
54
55 import org.eclipse.jgit.errors.CorruptObjectException;
56 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
57 import org.eclipse.jgit.errors.MissingObjectException;
58 import org.eclipse.jgit.lib.AnyObjectId;
59 import org.eclipse.jgit.lib.Constants;
60 import org.eclipse.jgit.lib.ObjectInserter;
61 import org.eclipse.jgit.lib.ObjectReader;
62 import org.eclipse.jgit.lib.PersonIdent;
63 import org.eclipse.jgit.util.MutableInteger;
64 import org.eclipse.jgit.util.RawParseUtils;
65 import org.eclipse.jgit.util.StringUtils;
66
67 /**
68 * An annotated tag.
69 */
70 public class RevTag extends RevObject {
71 /**
72 * Parse an annotated tag from its canonical format.
73 *
74 * This method constructs a temporary revision pool, parses the tag as
75 * supplied, and returns it to the caller. Since the tag was built inside of
76 * a private revision pool its object pointer will be initialized, but will
77 * not have its headers loaded.
78 *
79 * Applications are discouraged from using this API. Callers usually need
80 * more than one object. Use
81 * {@link org.eclipse.jgit.revwalk.RevWalk#parseTag(AnyObjectId)} to obtain
82 * a RevTag from an existing repository.
83 *
84 * @param raw
85 * the canonical formatted tag to be parsed.
86 * @return the parsed tag, in an isolated revision pool that is not
87 * available to the caller.
88 * @throws org.eclipse.jgit.errors.CorruptObjectException
89 * the tag contains a malformed header that cannot be handled.
90 */
91 public static RevTag parse(byte[] raw) throws CorruptObjectException {
92 return parse(new RevWalk((ObjectReader) null), raw);
93 }
94
95 /**
96 * Parse an annotated tag from its canonical format.
97 * <p>
98 * This method inserts the tag directly into the caller supplied revision
99 * pool, making it appear as though the tag exists in the repository, even
100 * if it doesn't. The repository under the pool is not affected.
101 * <p>
102 * The body of the tag (message, tagger, signature) is always retained in
103 * the returned {@code RevTag}, even if the supplied {@code RevWalk} has
104 * been configured with {@code setRetainBody(false)}.
105 *
106 * @param rw
107 * the revision pool to allocate the tag within. The tag's object
108 * pointer will be obtained from this pool.
109 * @param raw
110 * the canonical formatted tag to be parsed. This buffer will be
111 * retained by the returned {@code RevTag} and must not be
112 * modified by the caller.
113 * @return the parsed tag, in an isolated revision pool that is not
114 * available to the caller.
115 * @throws org.eclipse.jgit.errors.CorruptObjectException
116 * the tag contains a malformed header that cannot be handled.
117 */
118 public static RevTag parse(RevWalk rw, byte[] raw)
119 throws CorruptObjectException {
120 try (ObjectInserter.Formatter fmt = new ObjectInserter.Formatter()) {
121 RevTag r = rw.lookupTag(fmt.idFor(Constants.OBJ_TAG, raw));
122 r.parseCanonical(rw, raw);
123 r.buffer = raw;
124 return r;
125 }
126 }
127
128 private RevObject object;
129
130 private byte[] buffer;
131
132 private String tagName;
133
134 /**
135 * Create a new tag reference.
136 *
137 * @param id
138 * object name for the tag.
139 */
140 protected RevTag(AnyObjectId id) {
141 super(id);
142 }
143
144 @Override
145 void parseHeaders(RevWalk walk) throws MissingObjectException,
146 IncorrectObjectTypeException, IOException {
147 parseCanonical(walk, walk.getCachedBytes(this));
148 }
149
150 @Override
151 void parseBody(RevWalk walk) throws MissingObjectException,
152 IncorrectObjectTypeException, IOException {
153 if (buffer == null) {
154 buffer = walk.getCachedBytes(this);
155 if ((flags & PARSED) == 0)
156 parseCanonical(walk, buffer);
157 }
158 }
159
160 void parseCanonical(RevWalk walk, byte[] rawTag)
161 throws CorruptObjectException {
162 final MutableIntegerger.html#MutableInteger">MutableInteger pos = new MutableInteger();
163 final int oType;
164
165 pos.value = 53; // "object $sha1\ntype "
166 oType = Constants.decodeTypeString(this, rawTag, (byte) '\n', pos);
167 walk.idBuffer.fromString(rawTag, 7);
168 object = walk.lookupAny(walk.idBuffer, oType);
169
170 int p = pos.value += 4; // "tag "
171 final int nameEnd = RawParseUtils.nextLF(rawTag, p) - 1;
172 tagName = RawParseUtils.decode(UTF_8, rawTag, p, nameEnd);
173
174 if (walk.isRetainBody())
175 buffer = rawTag;
176 flags |= PARSED;
177 }
178
179 /** {@inheritDoc} */
180 @Override
181 public final int getType() {
182 return Constants.OBJ_TAG;
183 }
184
185 /**
186 * Parse the tagger identity from the raw buffer.
187 * <p>
188 * This method parses and returns the content of the tagger line, after
189 * taking the tag's character set into account and decoding the tagger
190 * name and email address. This method is fairly expensive and produces a
191 * new PersonIdent instance on each invocation. Callers should invoke this
192 * method only if they are certain they will be outputting the result, and
193 * should cache the return value for as long as necessary to use all
194 * information from it.
195 *
196 * @return identity of the tagger (name, email) and the time the tag
197 * was made by the tagger; null if no tagger line was found.
198 */
199 public final PersonIdent getTaggerIdent() {
200 final byte[] raw = buffer;
201 final int nameB = RawParseUtils.tagger(raw, 0);
202 if (nameB < 0)
203 return null;
204 return RawParseUtils.parsePersonIdent(raw, nameB);
205 }
206
207 /**
208 * Parse the complete tag message and decode it to a string.
209 * <p>
210 * This method parses and returns the message portion of the tag buffer,
211 * after taking the tag's character set into account and decoding the buffer
212 * using that character set. This method is a fairly expensive operation and
213 * produces a new string on each invocation.
214 *
215 * @return decoded tag message as a string. Never null.
216 */
217 public final String getFullMessage() {
218 byte[] raw = buffer;
219 int msgB = RawParseUtils.tagMessage(raw, 0);
220 if (msgB < 0) {
221 return ""; //$NON-NLS-1$
222 }
223 return RawParseUtils.decode(guessEncoding(), raw, msgB, raw.length);
224 }
225
226 /**
227 * Parse the tag message and return the first "line" of it.
228 * <p>
229 * The first line is everything up to the first pair of LFs. This is the
230 * "oneline" format, suitable for output in a single line display.
231 * <p>
232 * This method parses and returns the message portion of the tag buffer,
233 * after taking the tag's character set into account and decoding the buffer
234 * using that character set. This method is a fairly expensive operation and
235 * produces a new string on each invocation.
236 *
237 * @return decoded tag message as a string. Never null. The returned string
238 * does not contain any LFs, even if the first paragraph spanned
239 * multiple lines. Embedded LFs are converted to spaces.
240 */
241 public final String getShortMessage() {
242 byte[] raw = buffer;
243 int msgB = RawParseUtils.tagMessage(raw, 0);
244 if (msgB < 0) {
245 return ""; //$NON-NLS-1$
246 }
247
248 int msgE = RawParseUtils.endOfParagraph(raw, msgB);
249 String str = RawParseUtils.decode(guessEncoding(), raw, msgB, msgE);
250 if (RevCommit.hasLF(raw, msgB, msgE)) {
251 str = StringUtils.replaceLineBreaksWithSpace(str);
252 }
253 return str;
254 }
255
256 private Charset guessEncoding() {
257 try {
258 return RawParseUtils.parseEncoding(buffer);
259 } catch (IllegalCharsetNameException | UnsupportedCharsetException e) {
260 return UTF_8;
261 }
262 }
263
264 /**
265 * Get a reference to the object this tag was placed on.
266 * <p>
267 * Note that the returned object has only been looked up (see
268 * {@link org.eclipse.jgit.revwalk.RevWalk#lookupAny(AnyObjectId, int)}. To
269 * access the contents it needs to be parsed, see
270 * {@link org.eclipse.jgit.revwalk.RevWalk#parseHeaders(RevObject)} and
271 * {@link org.eclipse.jgit.revwalk.RevWalk#parseBody(RevObject)}.
272 * <p>
273 * As an alternative, use
274 * {@link org.eclipse.jgit.revwalk.RevWalk#peel(RevObject)} and pass this
275 * {@link org.eclipse.jgit.revwalk.RevTag} to peel it until the first
276 * non-tag object.
277 *
278 * @return object this tag refers to (only looked up, not parsed)
279 */
280 public final RevObject getObject() {
281 return object;
282 }
283
284 /**
285 * Get the name of this tag, from the tag header.
286 *
287 * @return name of the tag, according to the tag header.
288 */
289 public final String getTagName() {
290 return tagName;
291 }
292
293 /**
294 * Discard the message buffer to reduce memory usage.
295 * <p>
296 * After discarding the memory usage of the {@code RevTag} is reduced to
297 * only the {@link #getObject()} pointer and {@link #getTagName()}.
298 * Accessing other properties such as {@link #getTaggerIdent()} or either
299 * message function requires reloading the buffer by invoking
300 * {@link org.eclipse.jgit.revwalk.RevWalk#parseBody(RevObject)}.
301 *
302 * @since 4.0
303 */
304 public final void disposeBody() {
305 buffer = null;
306 }
307 }