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.lib;
45
46 import org.eclipse.jgit.annotations.NonNull;
47 import org.eclipse.jgit.annotations.Nullable;
48
49 /**
50 * A reference that indirectly points at another {@link Ref}.
51 * <p>
52 * A symbolic reference always derives its current value from the target
53 * reference.
54 */
55 public class SymbolicRef implements Ref {
56 private final String name;
57
58 private final Ref target;
59
60 /**
61 * Create a new ref pairing.
62 *
63 * @param refName
64 * name of this ref.
65 * @param target
66 * the ref we reference and derive our value from.
67 */
68 public SymbolicRef(@NonNull String refName, @NonNull Ref target) {
69 this.name = refName;
70 this.target = target;
71 }
72
73 @Override
74 @NonNull
75 public String getName() {
76 return name;
77 }
78
79 @Override
80 public boolean isSymbolic() {
81 return true;
82 }
83
84 @Override
85 @NonNull
86 public Ref getLeaf() {
87 Ref dst = getTarget();
88 while (dst.isSymbolic())
89 dst = dst.getTarget();
90 return dst;
91 }
92
93 @Override
94 @NonNull
95 public Ref getTarget() {
96 return target;
97 }
98
99 @Override
100 @Nullable
101 public ObjectId getObjectId() {
102 return getLeaf().getObjectId();
103 }
104
105 @Override
106 @NonNull
107 public Storage getStorage() {
108 return Storage.LOOSE;
109 }
110
111 @Override
112 @Nullable
113 public ObjectId getPeeledObjectId() {
114 return getLeaf().getPeeledObjectId();
115 }
116
117 @Override
118 public boolean isPeeled() {
119 return getLeaf().isPeeled();
120 }
121
122 @SuppressWarnings("nls")
123 @Override
124 public String toString() {
125 StringBuilder r = new StringBuilder();
126 r.append("SymbolicRef[");
127 Ref cur = this;
128 while (cur.isSymbolic()) {
129 r.append(cur.getName());
130 r.append(" -> ");
131 cur = cur.getTarget();
132 }
133 r.append(cur.getName());
134 r.append('=');
135 r.append(ObjectId.toString(cur.getObjectId()));
136 r.append("]");
137 return r.toString();
138 }
139 }