1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/rt/emul/mini/src/main/java/org/apidesign/bck2brwsr/emul/zip/Adler32.java Tue Feb 26 16:54:16 2013 +0100
1.3 @@ -0,0 +1,139 @@
1.4 +/* -*-mode:java; c-basic-offset:2; -*- */
1.5 +/*
1.6 +Copyright (c) 2000-2011 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 +final class Adler32 implements Checksum {
1.41 +
1.42 + // largest prime smaller than 65536
1.43 + static final private int BASE=65521;
1.44 + // NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1
1.45 + static final private int NMAX=5552;
1.46 +
1.47 + private long s1=1L;
1.48 + private long s2=0L;
1.49 +
1.50 + public void reset(long init){
1.51 + s1=init&0xffff;
1.52 + s2=(init>>16)&0xffff;
1.53 + }
1.54 +
1.55 + public void reset(){
1.56 + s1=1L;
1.57 + s2=0L;
1.58 + }
1.59 +
1.60 + public long getValue(){
1.61 + return ((s2<<16)|s1);
1.62 + }
1.63 +
1.64 + public void update(byte[] buf, int index, int len){
1.65 +
1.66 + if(len==1){
1.67 + s1+=buf[index++]&0xff; s2+=s1;
1.68 + s1%=BASE;
1.69 + s2%=BASE;
1.70 + return;
1.71 + }
1.72 +
1.73 + int len1 = len/NMAX;
1.74 + int len2 = len%NMAX;
1.75 + while(len1-->0) {
1.76 + int k=NMAX;
1.77 + len-=k;
1.78 + while(k-->0){
1.79 + s1+=buf[index++]&0xff; s2+=s1;
1.80 + }
1.81 + s1%=BASE;
1.82 + s2%=BASE;
1.83 + }
1.84 +
1.85 + int k=len2;
1.86 + len-=k;
1.87 + while(k-->0){
1.88 + s1+=buf[index++]&0xff; s2+=s1;
1.89 + }
1.90 + s1%=BASE;
1.91 + s2%=BASE;
1.92 + }
1.93 +
1.94 + public Adler32 copy(){
1.95 + Adler32 foo = new Adler32();
1.96 + foo.s1 = this.s1;
1.97 + foo.s2 = this.s2;
1.98 + return foo;
1.99 + }
1.100 +
1.101 + // The following logic has come from zlib.1.2.
1.102 + static long combine(long adler1, long adler2, long len2){
1.103 + long BASEL = (long)BASE;
1.104 + long sum1;
1.105 + long sum2;
1.106 + long rem; // unsigned int
1.107 +
1.108 + rem = len2 % BASEL;
1.109 + sum1 = adler1 & 0xffffL;
1.110 + sum2 = rem * sum1;
1.111 + sum2 %= BASEL; // MOD(sum2);
1.112 + sum1 += (adler2 & 0xffffL) + BASEL - 1;
1.113 + sum2 += ((adler1 >> 16) & 0xffffL) + ((adler2 >> 16) & 0xffffL) + BASEL - rem;
1.114 + if (sum1 >= BASEL) sum1 -= BASEL;
1.115 + if (sum1 >= BASEL) sum1 -= BASEL;
1.116 + if (sum2 >= (BASEL << 1)) sum2 -= (BASEL << 1);
1.117 + if (sum2 >= BASEL) sum2 -= BASEL;
1.118 + return sum1 | (sum2 << 16);
1.119 + }
1.120 +
1.121 +/*
1.122 + private java.util.zip.Adler32 adler=new java.util.zip.Adler32();
1.123 + public void update(byte[] buf, int index, int len){
1.124 + if(buf==null) {adler.reset();}
1.125 + else{adler.update(buf, index, len);}
1.126 + }
1.127 + public void reset(){
1.128 + adler.reset();
1.129 + }
1.130 + public void reset(long init){
1.131 + if(init==1L){
1.132 + adler.reset();
1.133 + }
1.134 + else{
1.135 + System.err.println("unsupported operation");
1.136 + }
1.137 + }
1.138 + public long getValue(){
1.139 + return adler.getValue();
1.140 + }
1.141 +*/
1.142 +}