1.1 --- a/emul/mini/src/main/java/org/apidesign/bck2brwsr/emul/zip/CRC32.java Fri Mar 22 16:59:47 2013 +0100
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,181 +0,0 @@
1.4 -/* -*-mode:java; c-basic-offset:2; -*- */
1.5 -/*
1.6 -Copyright (c) 2011 ymnk, JCraft,Inc. All rights reserved.
1.7 -
1.8 -Redistribution and use in source and binary forms, with or without
1.9 -modification, are permitted provided that the following conditions are met:
1.10 -
1.11 - 1. Redistributions of source code must retain the above copyright notice,
1.12 - this list of conditions and the following disclaimer.
1.13 -
1.14 - 2. Redistributions in binary form must reproduce the above copyright
1.15 - notice, this list of conditions and the following disclaimer in
1.16 - the documentation and/or other materials provided with the distribution.
1.17 -
1.18 - 3. The names of the authors may not be used to endorse or promote products
1.19 - derived from this software without specific prior written permission.
1.20 -
1.21 -THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
1.22 -INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
1.23 -FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
1.24 -INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
1.25 -INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.26 -LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
1.27 -OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.28 -LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.29 -NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
1.30 -EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.31 - */
1.32 -/*
1.33 - * This program is based on zlib-1.1.3, so all credit should go authors
1.34 - * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
1.35 - * and contributors of zlib.
1.36 - */
1.37 -
1.38 -package org.apidesign.bck2brwsr.emul.zip;
1.39 -
1.40 -import org.apidesign.bck2brwsr.emul.lang.System;
1.41 -
1.42 -final class CRC32 implements Checksum {
1.43 -
1.44 - /*
1.45 - * The following logic has come from RFC1952.
1.46 - */
1.47 - private int v = 0;
1.48 - private static int[] crc_table = null;
1.49 - static {
1.50 - crc_table = new int[256];
1.51 - for (int n = 0; n < 256; n++) {
1.52 - int c = n;
1.53 - for (int k = 8; --k >= 0; ) {
1.54 - if ((c & 1) != 0)
1.55 - c = 0xedb88320 ^ (c >>> 1);
1.56 - else
1.57 - c = c >>> 1;
1.58 - }
1.59 - crc_table[n] = c;
1.60 - }
1.61 - }
1.62 -
1.63 - public void update (byte[] buf, int index, int len) {
1.64 - int c = ~v;
1.65 - while (--len >= 0)
1.66 - c = crc_table[(c^buf[index++])&0xff]^(c >>> 8);
1.67 - v = ~c;
1.68 - }
1.69 -
1.70 - public void reset(){
1.71 - v = 0;
1.72 - }
1.73 -
1.74 - public void reset(long vv){
1.75 - v = (int)(vv&0xffffffffL);
1.76 - }
1.77 -
1.78 - public long getValue(){
1.79 - return (long)(v&0xffffffffL);
1.80 - }
1.81 -
1.82 - // The following logic has come from zlib.1.2.
1.83 - private static final int GF2_DIM = 32;
1.84 - static long combine(long crc1, long crc2, long len2){
1.85 - long row;
1.86 - long[] even = new long[GF2_DIM];
1.87 - long[] odd = new long[GF2_DIM];
1.88 -
1.89 - // degenerate case (also disallow negative lengths)
1.90 - if (len2 <= 0)
1.91 - return crc1;
1.92 -
1.93 - // put operator for one zero bit in odd
1.94 - odd[0] = 0xedb88320L; // CRC-32 polynomial
1.95 - row = 1;
1.96 - for (int n = 1; n < GF2_DIM; n++) {
1.97 - odd[n] = row;
1.98 - row <<= 1;
1.99 - }
1.100 -
1.101 - // put operator for two zero bits in even
1.102 - gf2_matrix_square(even, odd);
1.103 -
1.104 - // put operator for four zero bits in odd
1.105 - gf2_matrix_square(odd, even);
1.106 -
1.107 - // apply len2 zeros to crc1 (first square will put the operator for one
1.108 - // zero byte, eight zero bits, in even)
1.109 - do {
1.110 - // apply zeros operator for this bit of len2
1.111 - gf2_matrix_square(even, odd);
1.112 - if ((len2 & 1)!=0)
1.113 - crc1 = gf2_matrix_times(even, crc1);
1.114 - len2 >>= 1;
1.115 -
1.116 - // if no more bits set, then done
1.117 - if (len2 == 0)
1.118 - break;
1.119 -
1.120 - // another iteration of the loop with odd and even swapped
1.121 - gf2_matrix_square(odd, even);
1.122 - if ((len2 & 1)!=0)
1.123 - crc1 = gf2_matrix_times(odd, crc1);
1.124 - len2 >>= 1;
1.125 -
1.126 - // if no more bits set, then done
1.127 - } while (len2 != 0);
1.128 -
1.129 - /* return combined crc */
1.130 - crc1 ^= crc2;
1.131 - return crc1;
1.132 - }
1.133 -
1.134 - private static long gf2_matrix_times(long[] mat, long vec){
1.135 - long sum = 0;
1.136 - int index = 0;
1.137 - while (vec!=0) {
1.138 - if ((vec & 1)!=0)
1.139 - sum ^= mat[index];
1.140 - vec >>= 1;
1.141 - index++;
1.142 - }
1.143 - return sum;
1.144 - }
1.145 -
1.146 - static final void gf2_matrix_square(long[] square, long[] mat) {
1.147 - for (int n = 0; n < GF2_DIM; n++)
1.148 - square[n] = gf2_matrix_times(mat, mat[n]);
1.149 - }
1.150 -
1.151 - /*
1.152 - private java.util.zip.CRC32 crc32 = new java.util.zip.CRC32();
1.153 -
1.154 - public void update(byte[] buf, int index, int len){
1.155 - if(buf==null) {crc32.reset();}
1.156 - else{crc32.update(buf, index, len);}
1.157 - }
1.158 - public void reset(){
1.159 - crc32.reset();
1.160 - }
1.161 - public void reset(long init){
1.162 - if(init==0L){
1.163 - crc32.reset();
1.164 - }
1.165 - else{
1.166 - System.err.println("unsupported operation");
1.167 - }
1.168 - }
1.169 - public long getValue(){
1.170 - return crc32.getValue();
1.171 - }
1.172 -*/
1.173 - public CRC32 copy(){
1.174 - CRC32 foo = new CRC32();
1.175 - foo.v = this.v;
1.176 - return foo;
1.177 - }
1.178 -
1.179 - public static int[] getCRC32Table(){
1.180 - int[] tmp = new int[crc_table.length];
1.181 - System.arraycopy(crc_table, 0, tmp, 0, tmp.length);
1.182 - return tmp;
1.183 - }
1.184 -}