annotate src/com/jcraft/jzlib/CRC32.java @ 402:14aa0621aa7d stable-1.9.0

Backed out changeset 2f2b5a244a4d
author Carl Byington <carl@five-ten-sg.com>
date Mon, 20 Oct 2014 19:14:39 -0700
parents 46c2115ae1c8
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
357
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
1 /* -*-mode:java; c-basic-offset:2; -*- */
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
2 /*
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
3 Copyright (c) 2011 ymnk, JCraft,Inc. All rights reserved.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
4
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
5 Redistribution and use in source and binary forms, with or without
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
6 modification, are permitted provided that the following conditions are met:
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
7
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
8 1. Redistributions of source code must retain the above copyright notice,
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
9 this list of conditions and the following disclaimer.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
10
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
11 2. Redistributions in binary form must reproduce the above copyright
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
12 notice, this list of conditions and the following disclaimer in
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
13 the documentation and/or other materials provided with the distribution.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
14
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
15 3. The names of the authors may not be used to endorse or promote products
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
16 derived from this software without specific prior written permission.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
17
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
18 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
19 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
20 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
21 INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
22 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
23 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
24 OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
25 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
26 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
27 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
28 */
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
29 /*
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
30 * This program is based on zlib-1.1.3, so all credit should go authors
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
31 * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
32 * and contributors of zlib.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
33 */
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
34
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
35 package com.jcraft.jzlib;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
36
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
37 final public class CRC32 implements Checksum {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
38
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
39 /*
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
40 * The following logic has come from RFC1952.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
41 */
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
42 private int v = 0;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
43 private static int[] crc_table = null;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
44 static {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
45 crc_table = new int[256];
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
46 for (int n = 0; n < 256; n++) {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
47 int c = n;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
48 for (int k = 8; --k >= 0; ) {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
49 if ((c & 1) != 0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
50 c = 0xedb88320 ^ (c >>> 1);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
51 else
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
52 c = c >>> 1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
53 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
54 crc_table[n] = c;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
55 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
56 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
57
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
58 public void update (byte[] buf, int index, int len) {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
59 int c = ~v;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
60 while (--len >= 0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
61 c = crc_table[(c^buf[index++])&0xff]^(c >>> 8);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
62 v = ~c;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
63 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
64
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
65 public void reset(){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
66 v = 0;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
67 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
68
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
69 public void reset(long vv){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
70 v = (int)(vv&0xffffffffL);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
71 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
72
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
73 public long getValue(){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
74 return (long)(v&0xffffffffL);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
75 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
76
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
77 // The following logic has come from zlib.1.2.
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
78 private static final int GF2_DIM = 32;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
79 static long combine(long crc1, long crc2, long len2){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
80 long row;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
81 long[] even = new long[GF2_DIM];
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
82 long[] odd = new long[GF2_DIM];
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
83
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
84 // degenerate case (also disallow negative lengths)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
85 if (len2 <= 0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
86 return crc1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
87
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
88 // put operator for one zero bit in odd
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
89 odd[0] = 0xedb88320L; // CRC-32 polynomial
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
90 row = 1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
91 for (int n = 1; n < GF2_DIM; n++) {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
92 odd[n] = row;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
93 row <<= 1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
94 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
95
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
96 // put operator for two zero bits in even
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
97 gf2_matrix_square(even, odd);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
98
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
99 // put operator for four zero bits in odd
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
100 gf2_matrix_square(odd, even);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
101
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
102 // apply len2 zeros to crc1 (first square will put the operator for one
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
103 // zero byte, eight zero bits, in even)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
104 do {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
105 // apply zeros operator for this bit of len2
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
106 gf2_matrix_square(even, odd);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
107 if ((len2 & 1)!=0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
108 crc1 = gf2_matrix_times(even, crc1);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
109 len2 >>= 1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
110
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
111 // if no more bits set, then done
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
112 if (len2 == 0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
113 break;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
114
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
115 // another iteration of the loop with odd and even swapped
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
116 gf2_matrix_square(odd, even);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
117 if ((len2 & 1)!=0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
118 crc1 = gf2_matrix_times(odd, crc1);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
119 len2 >>= 1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
120
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
121 // if no more bits set, then done
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
122 } while (len2 != 0);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
123
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
124 /* return combined crc */
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
125 crc1 ^= crc2;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
126 return crc1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
127 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
128
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
129 private static long gf2_matrix_times(long[] mat, long vec){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
130 long sum = 0;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
131 int index = 0;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
132 while (vec!=0) {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
133 if ((vec & 1)!=0)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
134 sum ^= mat[index];
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
135 vec >>= 1;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
136 index++;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
137 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
138 return sum;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
139 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
140
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
141 static final void gf2_matrix_square(long[] square, long[] mat) {
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
142 for (int n = 0; n < GF2_DIM; n++)
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
143 square[n] = gf2_matrix_times(mat, mat[n]);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
144 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
145
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
146 /*
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
147 private java.util.zip.CRC32 crc32 = new java.util.zip.CRC32();
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
148
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
149 public void update(byte[] buf, int index, int len){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
150 if(buf==null) {crc32.reset();}
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
151 else{crc32.update(buf, index, len);}
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
152 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
153 public void reset(){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
154 crc32.reset();
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
155 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
156 public void reset(long init){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
157 if(init==0L){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
158 crc32.reset();
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
159 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
160 else{
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
161 System.err.println("unsupported operation");
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
162 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
163 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
164 public long getValue(){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
165 return crc32.getValue();
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
166 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
167 */
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
168 public CRC32 copy(){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
169 CRC32 foo = new CRC32();
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
170 foo.v = this.v;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
171 return foo;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
172 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
173
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
174 public static int[] getCRC32Table(){
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
175 int[] tmp = new int[crc_table.length];
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
176 System.arraycopy(crc_table, 0, tmp, 0, tmp.length);
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
177 return tmp;
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
178 }
46c2115ae1c8 update jzlib to a21be20213d66eff15904d925e9b721956a01ef7
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
179 }