| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Sun designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Sun in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| * |
| * THIS FILE WAS MODIFIED BY SUN MICROSYSTEMS, INC. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file and, per its terms, should not be removed: |
| * |
| * adler32.c -- compute the Adler-32 checksum of a data stream |
| * Copyright (C) 1995-1998 Mark Adler |
| * For conditions of distribution and use, see copyright notice in zlib.h |
| */ |
| |
| #include "zlib.h" |
| |
| #define BASE 65521L /* largest prime smaller than 65536 */ |
| #define NMAX 5552 |
| /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ |
| |
| #define DO1(buf,i) {s1 += buf[i]; s2 += s1;} |
| #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1); |
| #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2); |
| #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); |
| #define DO16(buf) DO8(buf,0); DO8(buf,8); |
| |
| /* ========================================================================= */ |
| uLong ZEXPORT adler32(adler, buf, len) |
| uLong adler; |
| const Bytef *buf; |
| uInt len; |
| { |
| unsigned long s1 = adler & 0xffff; |
| unsigned long s2 = (adler >> 16) & 0xffff; |
| int k; |
| |
| if (buf == Z_NULL) return 1L; |
| |
| while (len > 0) { |
| k = len < NMAX ? len : NMAX; |
| len -= k; |
| while (k >= 16) { |
| DO16(buf); |
| buf += 16; |
| k -= 16; |
| } |
| if (k != 0) do { |
| s1 += *buf++; |
| s2 += s1; |
| } while (--k); |
| s1 %= BASE; |
| s2 %= BASE; |
| } |
| return (s2 << 16) | s1; |
| } |