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