1 /*
2 * Copyright (C) 2010, Marc Strapetz <marc.strapetz@syntevo.com>
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 package org.eclipse.jgit.attributes;
44
45 /**
46 * Represents an attribute.
47 * <p>
48 * According to the man page, an attribute can have the following states:
49 * <ul>
50 * <li>Set - represented by {@link State#SET}</li>
51 * <li>Unset - represented by {@link State#UNSET}</li>
52 * <li>Set to a value - represented by {@link State#CUSTOM}</li>
53 * <li>Unspecified - used to revert an attribute . This is crucial in order to
54 * mark an attribute as unspecified in the attributes map and thus preventing
55 * following (with lower priority) nodes from setting the attribute to a value
56 * at all</li>
57 * </ul>
58 * </p>
59 *
60 * @since 3.7
61 */
62 public final class Attribute {
63
64 /**
65 * The attribute value state
66 * see also https://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
67 */
68 public static enum State {
69 /** the attribute is set */
70 SET,
71
72 /** the attribute is unset */
73 UNSET,
74
75 /**
76 * the attribute appears as if it would not be defined at all
77 *
78 * @since 4.2
79 */
80 UNSPECIFIED,
81
82 /** the attribute is set to a custom value */
83 CUSTOM
84 }
85
86 private final String key;
87 private final State state;
88 private final String value;
89
90 /**
91 * Creates a new instance
92 *
93 * @param key
94 * the attribute key. Should not be <code>null</code>.
95 * @param state
96 * the attribute state. It should be either {@link State#SET} or
97 * {@link State#UNSET}. In order to create a custom value
98 * attribute prefer the use of {@link #Attribute(String, String)}
99 * constructor.
100 */
101 public Attribute(String key, State state) {
102 this(key, state, null);
103 }
104
105 private Attribute(String key, State state, String value) {
106 if (key == null)
107 throw new NullPointerException(
108 "The key of an attribute should not be null"); //$NON-NLS-1$
109 if (state == null)
110 throw new NullPointerException(
111 "The state of an attribute should not be null"); //$NON-NLS-1$
112
113 this.key = key;
114 this.state = state;
115 this.value = value;
116 }
117
118 /**
119 * Creates a new instance.
120 *
121 * @param key
122 * the attribute key. Should not be <code>null</code>.
123 * @param value
124 * the custom attribute value
125 */
126 public Attribute(String key, String value) {
127 this(key, State.CUSTOM, value);
128 }
129
130 @Override
131 public boolean equals(Object obj) {
132 if (this == obj)
133 return true;
134 if (!(obj instanceof Attribute))
135 return false;
136 Attribute other = (Attribute) obj;
137 if (!key.equals(other.key))
138 return false;
139 if (state != other.state)
140 return false;
141 if (value == null) {
142 if (other.value != null)
143 return false;
144 } else if (!value.equals(other.value))
145 return false;
146 return true;
147 }
148
149 /**
150 * @return the attribute key (never returns <code>null</code>)
151 */
152 public String getKey() {
153 return key;
154 }
155
156 /**
157 * Returns the state.
158 *
159 * @return the state (never returns <code>null</code>)
160 */
161 public State getState() {
162 return state;
163 }
164
165 /**
166 * @return the attribute value (may be <code>null</code>)
167 */
168 public String getValue() {
169 return value;
170 }
171
172 @Override
173 public int hashCode() {
174 final int prime = 31;
175 int result = 1;
176 result = prime * result + key.hashCode();
177 result = prime * result + state.hashCode();
178 result = prime * result + ((value == null) ? 0 : value.hashCode());
179 return result;
180 }
181
182 @Override
183 public String toString() {
184 switch (state) {
185 case SET:
186 return key;
187 case UNSET:
188 return "-" + key; //$NON-NLS-1$
189 case UNSPECIFIED:
190 return "!" + key; //$NON-NLS-1$
191 case CUSTOM:
192 default:
193 return key + "=" + value; //$NON-NLS-1$
194 }
195 }
196 }