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zlib 1.2.3.1

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This commit is contained in:
Mark Adler
2011-09-09 23:25:27 -07:00
parent abf180a067
commit b1c19ca6d8
50 changed files with 3729 additions and 583 deletions
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60
deflate.c
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@@ -52,7 +52,7 @@
#include "deflate.h"
const char deflate_copyright[] =
" deflate 1.2.3 Copyright 1995-2005 Jean-loup Gailly ";
" deflate 1.2.3.1 Copyright 1995-2005 Jean-loup Gailly ";
/*
If you use the zlib library in a product, an acknowledgment is welcome
in the documentation of your product. If for some reason you cannot
@@ -481,33 +481,65 @@ int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
* resulting from using fixed blocks instead of stored blocks, which deflate
* can emit on compressed data for some combinations of the parameters.
*
* This function could be more sophisticated to provide closer upper bounds
* for every combination of windowBits and memLevel, as well as wrap.
* But even the conservative upper bound of about 14% expansion does not
* seem onerous for output buffer allocation.
* This function could be more sophisticated to provide closer upper bounds for
* every combination of windowBits and memLevel. But even the conservative
* upper bound of about 14% expansion does not seem onerous for output buffer
* allocation.
*/
uLong ZEXPORT deflateBound(strm, sourceLen)
z_streamp strm;
uLong sourceLen;
{
deflate_state *s;
uLong destLen;
uLong complen, wraplen;
Bytef *str;
/* conservative upper bound */
destLen = sourceLen +
((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11;
/* conservative upper bound for compressed data */
complen = sourceLen +
((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
/* if can't get parameters, return conservative bound */
/* if can't get parameters, return conservative bound plus zlib wrapper */
if (strm == Z_NULL || strm->state == Z_NULL)
return destLen;
return complen + 6;
/* compute wrapper length */
s = strm->state;
switch (s->wrap) {
case 0: /* raw deflate */
wraplen = 0;
break;
case 1: /* zlib wrapper */
wraplen = 6 + (s->strstart ? 4 : 0);
break;
case 2: /* gzip wrapper */
wraplen = 18;
if (s->gzhead != NULL) { /* user-supplied gzip header */
if (s->gzhead->extra != NULL)
wraplen += 2 + s->gzhead->extra_len;
str = s->gzhead->name;
if (str != NULL)
do {
wraplen++;
} while (*str++);
str = s->gzhead->comment;
if (str != NULL)
do {
wraplen++;
} while (*str++);
if (s->gzhead->hcrc)
wraplen += 2;
}
break;
default: /* for compiler happiness */
wraplen = 6;
}
/* if not default parameters, return conservative bound */
s = strm->state;
if (s->w_bits != 15 || s->hash_bits != 8 + 7)
return destLen;
return complen + wraplen;
/* default settings: return tight bound for that case */
return compressBound(sourceLen);
return compressBound(sourceLen) - 6 + wraplen;
}
/* =========================================================================