Transition to pulling open-vcdiff from repository, instead of using snapshot...

sdch/open_vcdiff/depot/opensource/open-vcdiff/src/adler32.c

Index: sdch/open_vcdiff/depot/opensource/open-vcdiff/src/adler32.c
===================================================================
--- sdch/open_vcdiff/depot/opensource/open-vcdiff/src/adler32.c	(revision 2678)
+++ sdch/open_vcdiff/depot/opensource/open-vcdiff/src/adler32.c	(working copy)
@@ -1,189 +0,0 @@
-/* adler32.c -- compute the Adler-32 checksum of a data stream
- * Copyright (C) 1995-2004 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
-
-/* @(#) $Id$ */
-
-#define ZLIB_INTERNAL
-#include "zlib.h"
-
-#define BASE 65521UL    /* 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)  {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 { \
-        if (a >= (BASE << 16)) a -= (BASE << 16); \
-        if (a >= (BASE << 15)) a -= (BASE << 15); \
-        if (a >= (BASE << 14)) a -= (BASE << 14); \
-        if (a >= (BASE << 13)) a -= (BASE << 13); \
-        if (a >= (BASE << 12)) a -= (BASE << 12); \
-        if (a >= (BASE << 11)) a -= (BASE << 11); \
-        if (a >= (BASE << 10)) a -= (BASE << 10); \
-        if (a >= (BASE << 9)) a -= (BASE << 9); \
-        if (a >= (BASE << 8)) a -= (BASE << 8); \
-        if (a >= (BASE << 7)) a -= (BASE << 7); \
-        if (a >= (BASE << 6)) a -= (BASE << 6); \
-        if (a >= (BASE << 5)) a -= (BASE << 5); \
-        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)
-#  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
-
-/* ========================================================================= */
-
-/* 
-   The adler32 code below computes, in effect,
-
-   uLong high = 0;
-   uLong low  = 1;
-   for (j = 0; j < len; j++) {
-     low  = (low  + buf[j]) % BASE;
-     high = (high + low) % BASE;
-   }
-   checksum = (high << 16) | low;
-
-   Both 16-bit halves of the checksum are between 0 and BASE-1 (inclusive).
-   Hence, the minimum possible checksum value is 0, and the maximum is
-   ((BASE-1) << 16) | (BASE-1).  Applications may have reserved values
-   outside this range to carry special meanings.
-
-   NOTE: If adler32() is changed in ANY way, be absolutely sure that the
-   change will NOT cause checksums previously stored to not match the data
-   they were originally intended to match, or expand the range in such a
-   way that values reserved by applications to carry special meanings now
-   become checksums of valid data.  Also, be sure to change adler32_range()
-   accordingly.
-
-   This explanation and adler32_range() are not part of original software
-   distribution.  They are added at Google (2006) in accordance with the
-   copyright notice in zlib.h, which permits alteration and redistribution
-   of the original software provided, among other things, that altered
-   source versions must be plainly marked as such and not misrepresented as
-   being the original software.  
-*/
-
-void ZEXPORT adler32_range(min, max)
-    uLong *min;
-    uLong *max;
-{
-    *min = 0L;
-    *max = ((BASE-1) << 16) | (BASE-1);
-}
-
-uLong ZEXPORT adler32(adler, buf, len)
-    uLong adler;
-    const Bytef *buf;
-    uInt len;
-{
-    unsigned long sum2;
-    unsigned n;
-
-    /* split Adler-32 into component sums */
-    sum2 = (adler >> 16) & 0xffff;
-    adler &= 0xffff;
-
-    /* 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;
-        }
-        while (len--) {
-            adler += *buf++;
-            sum2 += adler;
-        }
-        MOD(adler);
-        MOD(sum2);
-    }
-
-    /* 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);
-}