01: /*
02: * @(#)Checksum.java 1.6 06/10/10
03: *
04: * Copyright 1990-2006 Sun Microsystems, Inc. All Rights Reserved.
05: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
06: *
07: * This program is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU General Public License version
09: * 2 only, as published by the Free Software Foundation.
10: *
11: * This program is distributed in the hope that it will be useful, but
12: * WITHOUT ANY WARRANTY; without even the implied warranty of
13: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14: * General Public License version 2 for more details (a copy is
15: * included at /legal/license.txt).
16: *
17: * You should have received a copy of the GNU General Public License
18: * version 2 along with this work; if not, write to the Free Software
19: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA
21: *
22: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
23: * Clara, CA 95054 or visit www.sun.com if you need additional
24: * information or have any questions.
25: */
26:
27: package sun.tools.javazic;
28:
29: import java.util.zip.CRC32;
30:
31: /**
32: * Checksum provides methods for calculating a CRC32 value for a
33: * transitions table.
34: *
35: * @since 1.4
36: */
37: public class Checksum extends CRC32 {
38: /**
39: * Updates the CRC32 value from each byte of the given int
40: * value. The bytes are used in the big endian order.
41: * @param val the int value
42: */
43: public void update(int val) {
44: byte[] b = new byte[4];
45: b[0] = (byte) ((val >>> 24) & 0xff);
46: b[1] = (byte) ((val >>> 16) & 0xff);
47: b[2] = (byte) ((val >>> 8) & 0xff);
48: b[3] = (byte) (val & 0xff);
49: update(b);
50: }
51:
52: /**
53: * Updates the CRC32 value from each byte of the given long
54: * value. The bytes are used in the big endian order.
55: * @param val the long value
56: */
57: void update(long val) {
58: byte[] b = new byte[8];
59: b[0] = (byte) ((val >>> 56) & 0xff);
60: b[1] = (byte) ((val >>> 48) & 0xff);
61: b[2] = (byte) ((val >>> 40) & 0xff);
62: b[3] = (byte) ((val >>> 32) & 0xff);
63: b[4] = (byte) ((val >>> 24) & 0xff);
64: b[5] = (byte) ((val >>> 16) & 0xff);
65: b[6] = (byte) ((val >>> 8) & 0xff);
66: b[7] = (byte) (val & 0xff);
67: update(b);
68: }
69: }
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