From ef79bbde537d6b9c745a7d86cb9df1d04c35590d Mon Sep 17 00:00:00 2001 From: PCSX* teams Date: Tue, 16 Nov 2010 14:15:22 +0200 Subject: pcsxr-1.9.92 --- win32/zlib/adler32.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 win32/zlib/adler32.c (limited to 'win32/zlib/adler32.c') diff --git a/win32/zlib/adler32.c b/win32/zlib/adler32.c new file mode 100644 index 0000000..fae88b6 --- /dev/null +++ b/win32/zlib/adler32.c @@ -0,0 +1,48 @@ +/* adler32.c -- compute the Adler-32 checksum of a data stream + * Copyright (C) 1995-2002 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* @(#) $Id$ */ + +#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; +} -- cgit v1.2.3