annotate zlib/adler32.c @ 18:1424868939a8

Indenting
author darius
date Wed, 24 Dec 1997 12:38:35 +0000
parents 1040ca591f2e
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
10
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
1 /* adler32.c -- compute the Adler-32 checksum of a data stream
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
2 * Copyright (C) 1995 Mark Adler
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
3 * For conditions of distribution and use, see copyright notice in zlib.h
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
4 */
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
5
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
6 /* $Id: adler32.c,v 1.1.1.1 1997/12/06 04:37:17 darius Exp $ */
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
7
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
8 #include "zlib.h"
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
9
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
10 #define BASE 65521L /* largest prime smaller than 65536 */
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
11 #define NMAX 5552
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
12 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
13
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
14 #define DO1(buf) {s1 += *buf++; s2 += s1;}
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
15 #define DO2(buf) DO1(buf); DO1(buf);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
16 #define DO4(buf) DO2(buf); DO2(buf);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
17 #define DO8(buf) DO4(buf); DO4(buf);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
18 #define DO16(buf) DO8(buf); DO8(buf);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
19
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
20 /* ========================================================================= */
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
21 uLong adler32(adler, buf, len)
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
22 uLong adler;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
23 Bytef *buf;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
24 uInt len;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
25 {
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
26 unsigned long s1 = adler & 0xffff;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
27 unsigned long s2 = (adler >> 16) & 0xffff;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
28 int k;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
29
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
30 if (buf == Z_NULL) return 1L;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
31
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
32 while (len > 0) {
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
33 k = len < NMAX ? len : NMAX;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
34 len -= k;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
35 while (k >= 16) {
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
36 DO16(buf);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
37 k -= 16;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
38 }
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
39 if (k != 0) do {
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
40 DO1(buf);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
41 } while (--k);
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
42 s1 %= BASE;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
43 s2 %= BASE;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
44 }
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
45 return (s2 << 16) | s1;
1040ca591f2e First entry of Paradise Server 2.9 patch 10 Beta
darius
parents:
diff changeset
46 }