1 /*
2 * Copyright (C) 2008, Charles O'Farrell <charleso@charleso.org>
3 * Copyright (C) 2009-2010, Google Inc.
4 * Copyright (C) 2009, Robin Rosenberg <robin.rosenberg@dewire.com>
5 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
6 * and other copyright owners as documented in the project's IP log.
7 *
8 * This program and the accompanying materials are made available
9 * under the terms of the Eclipse Distribution License v1.0 which
10 * accompanies this distribution, is reproduced below, and is
11 * available at http://www.eclipse.org/org/documents/edl-v10.php
12 *
13 * All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or
16 * without modification, are permitted provided that the following
17 * conditions are met:
18 *
19 * - Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 *
22 * - Redistributions in binary form must reproduce the above
23 * copyright notice, this list of conditions and the following
24 * disclaimer in the documentation and/or other materials provided
25 * with the distribution.
26 *
27 * - Neither the name of the Eclipse Foundation, Inc. nor the
28 * names of its contributors may be used to endorse or promote
29 * products derived from this software without specific prior
30 * written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
33 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
34 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
37 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
39 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
40 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
41 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
42 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
43 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
44 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45 */
46
47 package org.eclipse.jgit.lib;
48
49 import java.io.IOException;
50 import java.io.StringWriter;
51 import java.util.Collection;
52 import java.util.Map;
53
54 import org.eclipse.jgit.internal.storage.file.RefDirectory;
55 import org.eclipse.jgit.util.RefList;
56 import org.eclipse.jgit.util.RefMap;
57
58 /**
59 * Writes out refs to the {@link org.eclipse.jgit.lib.Constants#INFO_REFS} and
60 * {@link org.eclipse.jgit.lib.Constants#PACKED_REFS} files.
61 *
62 * This class is abstract as the writing of the files must be handled by the
63 * caller. This is because it is used by transport classes as well.
64 */
65 public abstract class RefWriter {
66
67 private final Collection<Ref> refs;
68
69 /**
70 * <p>Constructor for RefWriter.</p>
71 *
72 * @param refs
73 * the complete set of references. This should have been computed
74 * by applying updates to the advertised refs already discovered.
75 */
76 public RefWriter(Collection<Ref> refs) {
77 this.refs = RefComparator.sort(refs);
78 }
79
80 /**
81 * <p>Constructor for RefWriter.</p>
82 *
83 * @param refs
84 * the complete set of references. This should have been computed
85 * by applying updates to the advertised refs already discovered.
86 */
87 public RefWriter(Map<String, Ref> refs) {
88 if (refs instanceof RefMap)
89 this.refs = refs.values();
90 else
91 this.refs = RefComparator.sort(refs.values());
92 }
93
94 /**
95 * <p>Constructor for RefWriter.</p>
96 *
97 * @param refs
98 * the complete set of references. This should have been computed
99 * by applying updates to the advertised refs already discovered.
100 */
101 public RefWriter(RefList<Ref> refs) {
102 this.refs = refs.asList();
103 }
104
105 /**
106 * Rebuild the {@link org.eclipse.jgit.lib.Constants#INFO_REFS}.
107 * <p>
108 * This method rebuilds the contents of the
109 * {@link org.eclipse.jgit.lib.Constants#INFO_REFS} file to match the passed
110 * list of references.
111 *
112 * @throws java.io.IOException
113 * writing is not supported, or attempting to write the file
114 * failed, possibly due to permissions or remote disk full, etc.
115 */
116 public void writeInfoRefs() throws IOException {
117 final StringWriter w = new StringWriter();
118 final char[] tmp = new char[Constants.OBJECT_ID_STRING_LENGTH];
119 for (Ref r : refs) {
120 if (Constants.HEAD.equals(r.getName())) {
121 // Historically HEAD has never been published through
122 // the INFO_REFS file. This is a mistake, but its the
123 // way things are.
124 //
125 continue;
126 }
127
128 ObjectId objectId = r.getObjectId();
129 if (objectId == null) {
130 // Symrefs to unborn branches aren't advertised in the info/refs
131 // file.
132 continue;
133 }
134 objectId.copyTo(tmp, w);
135 w.write('\t');
136 w.write(r.getName());
137 w.write('\n');
138
139 ObjectId peeledObjectId = r.getPeeledObjectId();
140 if (peeledObjectId != null) {
141 peeledObjectId.copyTo(tmp, w);
142 w.write('\t');
143 w.write(r.getName());
144 w.write("^{}\n"); //$NON-NLS-1$
145 }
146 }
147 writeFile(Constants.INFO_REFS, Constants.encode(w.toString()));
148 }
149
150 /**
151 * Rebuild the {@link org.eclipse.jgit.lib.Constants#PACKED_REFS} file.
152 * <p>
153 * This method rebuilds the contents of the
154 * {@link org.eclipse.jgit.lib.Constants#PACKED_REFS} file to match the
155 * passed list of references, including only those refs that have a storage
156 * type of {@link org.eclipse.jgit.lib.Ref.Storage#PACKED}.
157 *
158 * @throws java.io.IOException
159 * writing is not supported, or attempting to write the file
160 * failed, possibly due to permissions or remote disk full, etc.
161 */
162 public void writePackedRefs() throws IOException {
163 boolean peeled = false;
164 for (Ref r : refs) {
165 if (r.getStorage().isPacked() && r.isPeeled()) {
166 peeled = true;
167 break;
168 }
169 }
170
171 final StringWriter w = new StringWriter();
172 if (peeled) {
173 w.write(RefDirectory.PACKED_REFS_HEADER);
174 if (peeled)
175 w.write(RefDirectory.PACKED_REFS_PEELED);
176 w.write('\n');
177 }
178
179 final char[] tmp = new char[Constants.OBJECT_ID_STRING_LENGTH];
180 for (Ref r : refs) {
181 if (r.getStorage() != Ref.Storage.PACKED)
182 continue;
183
184 ObjectId objectId = r.getObjectId();
185 if (objectId == null) {
186 // A packed ref cannot be a symref, let alone a symref
187 // to an unborn branch.
188 throw new NullPointerException();
189 }
190 objectId.copyTo(tmp, w);
191 w.write(' ');
192 w.write(r.getName());
193 w.write('\n');
194
195 ObjectId peeledObjectId = r.getPeeledObjectId();
196 if (peeledObjectId != null) {
197 w.write('^');
198 peeledObjectId.copyTo(tmp, w);
199 w.write('\n');
200 }
201 }
202 writeFile(Constants.PACKED_REFS, Constants.encode(w.toString()));
203 }
204
205 /**
206 * Handles actual writing of ref files to the git repository, which may
207 * differ slightly depending on the destination and transport.
208 *
209 * @param file
210 * path to ref file.
211 * @param content
212 * byte content of file to be written.
213 * @throws java.io.IOException
214 */
215 protected abstract void writeFile(String file, byte[] content)
216 throws IOException;
217 }