1 /*
2 * Copyright (C) 2008-2009, Google Inc.
3 * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
4 * Copyright (C) 2007-2009, Robin Rosenberg <robin.rosenberg@dewire.com>
5 * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org>
6 * and other copyright owners as documented in the project's IP log.
7 *
8 * This program and the accompanying materials are made available
9 * under the terms of the Eclipse Distribution License v1.0 which
10 * accompanies this distribution, is reproduced below, and is
11 * available at http://www.eclipse.org/org/documents/edl-v10.php
12 *
13 * All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or
16 * without modification, are permitted provided that the following
17 * conditions are met:
18 *
19 * - Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 *
22 * - Redistributions in binary form must reproduce the above
23 * copyright notice, this list of conditions and the following
24 * disclaimer in the documentation and/or other materials provided
25 * with the distribution.
26 *
27 * - Neither the name of the Eclipse Foundation, Inc. nor the
28 * names of its contributors may be used to endorse or promote
29 * products derived from this software without specific prior
30 * written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
33 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
34 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
37 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
39 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
40 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
41 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
42 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
43 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
44 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45 */
46
47 package org.eclipse.jgit.lib;
48
49 import java.text.MessageFormat;
50
51 import org.eclipse.jgit.errors.InvalidObjectIdException;
52 import org.eclipse.jgit.internal.JGitText;
53 import org.eclipse.jgit.util.NB;
54 import org.eclipse.jgit.util.RawParseUtils;
55
56 /**
57 * A mutable SHA-1 abstraction.
58 */
59 public class MutableObjectId extends AnyObjectId {
60 /**
61 * Empty constructor. Initialize object with default (zeros) value.
62 */
63 public MutableObjectId() {
64 super();
65 }
66
67 /**
68 * Copying constructor.
69 *
70 * @param src
71 * original entry, to copy id from
72 */
73 MutableObjectId(MutableObjectId src) {
74 fromObjectId(src);
75 }
76
77 /**
78 * Set any byte in the id.
79 *
80 * @param index
81 * index of the byte to set in the raw form of the ObjectId. Must
82 * be in range [0, {@link Constants#OBJECT_ID_LENGTH}).
83 * @param value
84 * the value of the specified byte at {@code index}. Values are
85 * unsigned and thus are in the range [0,255] rather than the
86 * signed byte range of [-128, 127].
87 * @throws ArrayIndexOutOfBoundsException
88 * {@code index} is less than 0, equal to
89 * {@link Constants#OBJECT_ID_LENGTH}, or greater than
90 * {@link Constants#OBJECT_ID_LENGTH}.
91 */
92 public void setByte(int index, int value) {
93 switch (index >> 2) {
94 case 0:
95 w1 = set(w1, index & 3, value);
96 break;
97 case 1:
98 w2 = set(w2, index & 3, value);
99 break;
100 case 2:
101 w3 = set(w3, index & 3, value);
102 break;
103 case 3:
104 w4 = set(w4, index & 3, value);
105 break;
106 case 4:
107 w5 = set(w5, index & 3, value);
108 break;
109 default:
110 throw new ArrayIndexOutOfBoundsException(index);
111 }
112 }
113
114 private static int set(int w, int index, int value) {
115 value &= 0xff;
116
117 switch (index) {
118 case 0:
119 return (w & 0x00ffffff) | (value << 24);
120 case 1:
121 return (w & 0xff00ffff) | (value << 16);
122 case 2:
123 return (w & 0xffff00ff) | (value << 8);
124 case 3:
125 return (w & 0xffffff00) | value;
126 default:
127 throw new ArrayIndexOutOfBoundsException();
128 }
129 }
130
131 /** Make this id match {@link ObjectId#zeroId()}. */
132 public void clear() {
133 w1 = 0;
134 w2 = 0;
135 w3 = 0;
136 w4 = 0;
137 w5 = 0;
138 }
139
140 /**
141 * Copy an ObjectId into this mutable buffer.
142 *
143 * @param src
144 * the source id to copy from.
145 */
146 public void fromObjectId(AnyObjectId src) {
147 this.w1 = src.w1;
148 this.w2 = src.w2;
149 this.w3 = src.w3;
150 this.w4 = src.w4;
151 this.w5 = src.w5;
152 }
153
154 /**
155 * Convert an ObjectId from raw binary representation.
156 *
157 * @param bs
158 * the raw byte buffer to read from. At least 20 bytes must be
159 * available within this byte array.
160 */
161 public void fromRaw(final byte[] bs) {
162 fromRaw(bs, 0);
163 }
164
165 /**
166 * Convert an ObjectId from raw binary representation.
167 *
168 * @param bs
169 * the raw byte buffer to read from. At least 20 bytes after p
170 * must be available within this byte array.
171 * @param p
172 * position to read the first byte of data from.
173 */
174 public void fromRaw(final byte[] bs, final int p) {
175 w1 = NB.decodeInt32(bs, p);
176 w2 = NB.decodeInt32(bs, p + 4);
177 w3 = NB.decodeInt32(bs, p + 8);
178 w4 = NB.decodeInt32(bs, p + 12);
179 w5 = NB.decodeInt32(bs, p + 16);
180 }
181
182 /**
183 * Convert an ObjectId from binary representation expressed in integers.
184 *
185 * @param ints
186 * the raw int buffer to read from. At least 5 integers must be
187 * available within this integers array.
188 */
189 public void fromRaw(final int[] ints) {
190 fromRaw(ints, 0);
191 }
192
193 /**
194 * Convert an ObjectId from binary representation expressed in integers.
195 *
196 * @param ints
197 * the raw int buffer to read from. At least 5 integers after p
198 * must be available within this integers array.
199 * @param p
200 * position to read the first integer of data from.
201 *
202 */
203 public void fromRaw(final int[] ints, final int p) {
204 w1 = ints[p];
205 w2 = ints[p + 1];
206 w3 = ints[p + 2];
207 w4 = ints[p + 3];
208 w5 = ints[p + 4];
209 }
210
211 /**
212 * Convert an ObjectId from hex characters (US-ASCII).
213 *
214 * @param buf
215 * the US-ASCII buffer to read from. At least 40 bytes after
216 * offset must be available within this byte array.
217 * @param offset
218 * position to read the first character from.
219 */
220 public void fromString(final byte[] buf, final int offset) {
221 fromHexString(buf, offset);
222 }
223
224 /**
225 * Convert an ObjectId from hex characters.
226 *
227 * @param str
228 * the string to read from. Must be 40 characters long.
229 */
230 public void fromString(final String str) {
231 if (str.length() != Constants.OBJECT_ID_STRING_LENGTH)
232 throw new IllegalArgumentException(MessageFormat.format(
233 JGitText.get().invalidId, str));
234 fromHexString(Constants.encodeASCII(str), 0);
235 }
236
237 private void fromHexString(final byte[] bs, int p) {
238 try {
239 w1 = RawParseUtils.parseHexInt32(bs, p);
240 w2 = RawParseUtils.parseHexInt32(bs, p + 8);
241 w3 = RawParseUtils.parseHexInt32(bs, p + 16);
242 w4 = RawParseUtils.parseHexInt32(bs, p + 24);
243 w5 = RawParseUtils.parseHexInt32(bs, p + 32);
244 } catch (ArrayIndexOutOfBoundsException e1) {
245 throw new InvalidObjectIdException(bs, p,
246 Constants.OBJECT_ID_STRING_LENGTH);
247 }
248 }
249
250 @Override
251 public ObjectId toObjectId() {
252 return new ObjectId(this);
253 }
254 }