1 /*
2 * Copyright (C) 2013, 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.internal.storage.pack;
45
46 /**
47 * A pack file extension.
48 */
49 public class PackExt {
50 private static volatile PackExt[] VALUES = new PackExt[] {};
51
52 /** A pack file extension. */
53 public static final PackExt PACK = newPackExt("pack"); //$NON-NLS-1$
54
55 /** A pack index file extension. */
56 public static final PackExt INDEX = newPackExt("idx"); //$NON-NLS-1$
57
58 /** A keep pack file extension. */
59 public static final PackExt KEEP = newPackExt("keep"); //$NON-NLS-1$
60
61 /** A pack bitmap index file extension. */
62 public static final PackExt BITMAP_INDEX = newPackExt("bitmap"); //$NON-NLS-1$
63
64 /** A reftable file. */
65 public static final PackExt REFTABLE = newPackExt("ref"); //$NON-NLS-1$
66
67 /**
68 * Get all of the PackExt values.
69 *
70 * @return all of the PackExt values.
71 */
72 public static PackExt[] values() {
73 return VALUES;
74 }
75
76 /**
77 * Returns a PackExt for the file extension and registers it in the values
78 * array.
79 *
80 * @param ext
81 * the file extension.
82 * @return the PackExt for the ext
83 */
84 public synchronized static PackExt newPackExt(String ext) {
85 PackExt[] dst = new PackExt[VALUES.length + 1];
86 for (int i = 0; i < VALUES.length; i++) {
87 PackExt packExt = VALUES[i];
88 if (packExt.getExtension().equals(ext))
89 return packExt;
90 dst[i] = packExt;
91 }
92 if (VALUES.length >= 32)
93 throw new IllegalStateException(
94 "maximum number of pack extensions exceeded"); //$NON-NLS-1$
95
96 PackExt value = new PackExt(ext, VALUES.length);
97 dst[VALUES.length] = value;
98 VALUES = dst;
99 return value;
100 }
101
102 private final String ext;
103
104 private final int pos;
105
106 private PackExt(String ext, int pos) {
107 this.ext = ext;
108 this.pos = pos;
109 }
110
111 /**
112 * Get the file extension.
113 *
114 * @return the file extension.
115 */
116 public String getExtension() {
117 return ext;
118 }
119
120 /**
121 * Get the position of the extension in the values array.
122 *
123 * @return the position of the extension in the values array.
124 */
125 public int getPosition() {
126 return pos;
127 }
128
129 /**
130 * Get the bit mask of the extension e.g {@code 1 << getPosition()}.
131 *
132 * @return the bit mask of the extension e.g {@code 1 << getPosition()}.
133 */
134 public int getBit() {
135 return 1 << getPosition();
136 }
137
138 /** {@inheritDoc} */
139 @Override
140 public String toString() {
141 return String.format("PackExt[%s, bit=0x%s]", getExtension(), //$NON-NLS-1$
142 Integer.toHexString(getBit()));
143 }
144 }