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