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zlib 1.2.3

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git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@4183 212acab6-be3b-0410-9dea-997c60f758d6
This commit is contained in:
kichik 2005-07-22 17:42:47 +00:00
parent 0a19777905
commit aa553c8a24
16 changed files with 578 additions and 134 deletions
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111
Contrib/zip2exe/zlib/adler32.c
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@ -1,5 +1,5 @@
/* adler32.c -- compute the Adler-32 checksum of a data stream
* Copyright (C) 1995-2003 Mark Adler
* Copyright (C) 1995-2004 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
@ -12,12 +12,13 @@
#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 DO1(buf,i) {adler += (buf)[i]; sum2 += adler;}
#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);
/* use NO_DIVIDE if your processor does not do division in hardware */
#ifdef NO_DIVIDE
# define MOD(a) \
do { \
@ -39,8 +40,17 @@
if (a >= (BASE << 1)) a -= (BASE << 1); \
if (a >= BASE) a -= BASE; \
} while (0)
# define MOD4(a) \
do { \
if (a >= (BASE << 4)) a -= (BASE << 4); \
if (a >= (BASE << 3)) a -= (BASE << 3); \
if (a >= (BASE << 2)) a -= (BASE << 2); \
if (a >= (BASE << 1)) a -= (BASE << 1); \
if (a >= BASE) a -= BASE; \
} while (0)
#else
# define MOD(a) a %= BASE
# define MOD4(a) a %= BASE
#endif
/* ========================================================================= */
@ -49,26 +59,91 @@ uLong ZEXPORT adler32(adler, buf, len)
const Bytef *buf;
uInt len;
{
unsigned long s1 = adler & 0xffff;
unsigned long s2 = (adler >> 16) & 0xffff;
int k;
unsigned long sum2;
unsigned n;
if (buf == Z_NULL) return 1L;
/* split Adler-32 into component sums */
sum2 = (adler >> 16) & 0xffff;
adler &= 0xffff;
while (len > 0) {
k = len < NMAX ? (int)len : NMAX;
len -= k;
while (k >= 16) {
/* in case user likes doing a byte at a time, keep it fast */
if (len == 1) {
adler += buf[0];
if (adler >= BASE)
adler -= BASE;
sum2 += adler;
if (sum2 >= BASE)
sum2 -= BASE;
return adler | (sum2 << 16);
}
/* initial Adler-32 value (deferred check for len == 1 speed) */
if (buf == Z_NULL)
return 1L;
/* in case short lengths are provided, keep it somewhat fast */
if (len < 16) {
while (len--) {
adler += *buf++;
sum2 += adler;
}
if (adler >= BASE)
adler -= BASE;
MOD4(sum2); /* only added so many BASE's */
return adler | (sum2 << 16);
}
/* do length NMAX blocks -- requires just one modulo operation */
while (len >= NMAX) {
len -= NMAX;
n = NMAX / 16; /* NMAX is divisible by 16 */
do {
DO16(buf); /* 16 sums unrolled */
buf += 16;
} while (--n);
MOD(adler);
MOD(sum2);
}
/* do remaining bytes (less than NMAX, still just one modulo) */
if (len) { /* avoid modulos if none remaining */
while (len >= 16) {
len -= 16;
DO16(buf);
buf += 16;
k -= 16;
}
if (k != 0) do {
s1 += *buf++;
s2 += s1;
} while (--k);
MOD(s1);
MOD(s2);
while (len--) {
adler += *buf++;
sum2 += adler;
}
MOD(adler);
MOD(sum2);
}
return (s2 << 16) | s1;
/* return recombined sums */
return adler | (sum2 << 16);
}
/* ========================================================================= */
uLong ZEXPORT adler32_combine(adler1, adler2, len2)
uLong adler1;
uLong adler2;
z_off_t len2;
{
unsigned long sum1;
unsigned long sum2;
unsigned rem;
/* the derivation of this formula is left as an exercise for the reader */
rem = (unsigned)(len2 % BASE);
sum1 = adler1 & 0xffff;
sum2 = rem * sum1;
MOD(sum2);
sum1 += (adler2 & 0xffff) + BASE - 1;
sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
if (sum1 > BASE) sum1 -= BASE;
if (sum1 > BASE) sum1 -= BASE;
if (sum2 > (BASE << 1)) sum2 -= (BASE << 1);
if (sum2 > BASE) sum2 -= BASE;
return sum1 | (sum2 << 16);
}