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 @NonNull
74 public String getName() {
75 return name;
76 }
77
78 public boolean isSymbolic() {
79 return true;
80 }
81
82 @NonNull
83 public Ref getLeaf() {
84 Ref dst = getTarget();
85 while (dst.isSymbolic())
86 dst = dst.getTarget();
87 return dst;
88 }
89
90 @NonNull
91 public Ref getTarget() {
92 return target;
93 }
94
95 @Nullable
96 public ObjectId getObjectId() {
97 return getLeaf().getObjectId();
98 }
99
100 @NonNull
101 public Storage getStorage() {
102 return Storage.LOOSE;
103 }
104
105 @Nullable
106 public ObjectId getPeeledObjectId() {
107 return getLeaf().getPeeledObjectId();
108 }
109
110 public boolean isPeeled() {
111 return getLeaf().isPeeled();
112 }
113
114 @SuppressWarnings("nls")
115 @Override
116 public String toString() {
117 StringBuilder r = new StringBuilder();
118 r.append("SymbolicRef[");
119 Ref cur = this;
120 while (cur.isSymbolic()) {
121 r.append(cur.getName());
122 r.append(" -> ");
123 cur = cur.getTarget();
124 }
125 r.append(cur.getName());
126 r.append('=');
127 r.append(ObjectId.toString(cur.getObjectId()));
128 r.append("]");
129 return r.toString();
130 }
131 }