[master] 89d697b28 Cherry-pick the trivial parts of zlib 1.2.13
Poul-Henning Kamp
phk at FreeBSD.org
Mon Dec 19 12:24:09 UTC 2022
commit 89d697b2812feebaf602d0f721fb89466879d0f7
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date: Mon Dec 19 10:36:53 2022 +0000
Cherry-pick the trivial parts of zlib 1.2.13
diff --git a/lib/libvgz/crc32.c b/lib/libvgz/crc32.c
index 0f59da66a..aee728a25 100644
--- a/lib/libvgz/crc32.c
+++ b/lib/libvgz/crc32.c
@@ -647,8 +647,8 @@ unsigned long ZEXPORT crc32_z(crc, buf, len)
len &= 7;
/* Do three interleaved CRCs to realize the throughput of one crc32x
- instruction per cycle. Each CRC is calcuated on Z_BATCH words. The three
- CRCs are combined into a single CRC after each set of batches. */
+ instruction per cycle. Each CRC is calculated on Z_BATCH words. The
+ three CRCs are combined into a single CRC after each set of batches. */
while (num >= 3 * Z_BATCH) {
crc1 = 0;
crc2 = 0;
diff --git a/lib/libvgz/deflate.c b/lib/libvgz/deflate.c
index 69222e189..43dede2bb 100644
--- a/lib/libvgz/deflate.c
+++ b/lib/libvgz/deflate.c
@@ -292,6 +292,8 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
if (windowBits < 0) { /* suppress zlib wrapper */
wrap = 0;
+ if (windowBits < -15)
+ return Z_STREAM_ERROR;
windowBits = -windowBits;
}
#ifdef GZIP
@@ -690,36 +692,50 @@ int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
}
/* =========================================================================
- * For the default windowBits of 15 and memLevel of 8, this function returns
- * a close to exact, as well as small, upper bound on the compressed size.
- * They are coded as constants here for a reason--if the #define's are
- * changed, then this function needs to be changed as well. The return
- * value for 15 and 8 only works for those exact settings.
+ * For the default windowBits of 15 and memLevel of 8, this function returns a
+ * close to exact, as well as small, upper bound on the compressed size. This
+ * is an expansion of ~0.03%, plus a small constant.
*
- * For any setting other than those defaults for windowBits and memLevel,
- * the value returned is a conservative worst case for the maximum expansion
- * resulting from using fixed blocks instead of stored blocks, which deflate
- * can emit on compressed data for some combinations of the parameters.
+ * For any setting other than those defaults for windowBits and memLevel, one
+ * of two worst case bounds is returned. This is at most an expansion of ~4% or
+ * ~13%, plus a small constant.
*
- * 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.
+ * Both the 0.03% and 4% derive from the overhead of stored blocks. The first
+ * one is for stored blocks of 16383 bytes (memLevel == 8), whereas the second
+ * is for stored blocks of 127 bytes (the worst case memLevel == 1). The
+ * expansion results from five bytes of header for each stored block.
+ *
+ * The larger expansion of 13% results from a window size less than or equal to
+ * the symbols buffer size (windowBits <= memLevel + 7). In that case some of
+ * the data being compressed may have slid out of the sliding window, impeding
+ * a stored block from being emitted. Then the only choice is a fixed or
+ * dynamic block, where a fixed block limits the maximum expansion to 9 bits
+ * per 8-bit byte, plus 10 bits for every block. The smallest block size for
+ * which this can occur is 255 (memLevel == 2).
+ *
+ * Shifts are used to approximate divisions, for speed.
*/
uLong ZEXPORT deflateBound(strm, sourceLen)
z_streamp strm;
uLong sourceLen;
{
deflate_state *s;
- uLong complen, wraplen;
+ uLong fixedlen, storelen, wraplen;
+
+ /* upper bound for fixed blocks with 9-bit literals and length 255
+ (memLevel == 2, which is the lowest that may not use stored blocks) --
+ ~13% overhead plus a small constant */
+ fixedlen = sourceLen + (sourceLen >> 3) + (sourceLen >> 8) +
+ (sourceLen >> 9) + 4;
- /* conservative upper bound for compressed data */
- complen = sourceLen +
- ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
+ /* upper bound for stored blocks with length 127 (memLevel == 1) --
+ ~4% overhead plus a small constant */
+ storelen = sourceLen + (sourceLen >> 5) + (sourceLen >> 7) +
+ (sourceLen >> 11) + 7;
- /* if can't get parameters, return conservative bound plus zlib wrapper */
+ /* if can't get parameters, return larger bound plus a zlib wrapper */
if (deflateStateCheck(strm))
- return complen + 6;
+ return (fixedlen > storelen ? fixedlen : storelen) + 6;
/* compute wrapper length */
s = strm->state;
@@ -756,11 +772,12 @@ uLong ZEXPORT deflateBound(strm, sourceLen)
wraplen = 6;
}
- /* if not default parameters, return conservative bound */
+ /* if not default parameters, return one of the conservative bounds */
if (s->w_bits != 15 || s->hash_bits != 8 + 7)
- return complen + wraplen;
+ return (s->w_bits <= s->hash_bits ? fixedlen : storelen) + wraplen;
- /* default settings: return tight bound for that case */
+ /* default settings: return tight bound for that case -- ~0.03% overhead
+ plus a small constant */
return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
(sourceLen >> 25) + 13 - 6 + wraplen;
}
@@ -1353,7 +1370,8 @@ local uInt longest_match(s, cur_match)
*/
if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
- Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+ Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
+ "need lookahead");
do {
Assert(cur_match < s->strstart, "no future");
@@ -1377,7 +1395,7 @@ local uInt longest_match(s, cur_match)
/* It is not necessary to compare scan[2] and match[2] since they are
* always equal when the other bytes match, given that the hash keys
* are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
- * strstart+3, +5, ... up to strstart+257. We check for insufficient
+ * strstart + 3, + 5, up to strstart + 257. We check for insufficient
* lookahead only every 4th comparison; the 128th check will be made
* at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
* necessary to put more guard bytes at the end of the window, or
@@ -1394,7 +1412,8 @@ local uInt longest_match(s, cur_match)
/* The funny "do {}" generates better code on most compilers */
/* Here, scan <= window+strstart+257 */
- Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+ Assert(scan <= s->window + (unsigned)(s->window_size - 1),
+ "wild scan");
if (*scan == *match) scan++;
len = (MAX_MATCH - 1) - (int)(strend-scan);
@@ -1426,7 +1445,8 @@ local uInt longest_match(s, cur_match)
*++scan == *++match && *++scan == *++match &&
scan < strend);
- Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+ Assert(scan <= s->window + (unsigned)(s->window_size - 1),
+ "wild scan");
len = MAX_MATCH - (int)(strend - scan);
scan = strend - MAX_MATCH;
@@ -1471,7 +1491,8 @@ local uInt longest_match(s, cur_match)
*/
Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
- Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+ Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
+ "need lookahead");
Assert(cur_match < s->strstart, "no future");
@@ -1717,7 +1738,7 @@ local void fill_window(s)
*
* deflate_stored() is written to minimize the number of times an input byte is
* copied. It is most efficient with large input and output buffers, which
- * maximizes the opportunites to have a single copy from next_in to next_out.
+ * maximizes the opportunities to have a single copy from next_in to next_out.
*/
local block_state deflate_stored(s, flush)
deflate_state *s;
@@ -2179,7 +2200,8 @@ local block_state deflate_rle(s, flush)
if (s->match_length > s->lookahead)
s->match_length = s->lookahead;
}
- Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
+ Assert(scan <= s->window + (uInt)(s->window_size - 1),
+ "wild scan");
}
/* Emit match if have run of MIN_MATCH or longer, else emit literal */
diff --git a/lib/libvgz/deflate.h b/lib/libvgz/deflate.h
index 17c226113..1a06cd5f2 100644
--- a/lib/libvgz/deflate.h
+++ b/lib/libvgz/deflate.h
@@ -329,8 +329,8 @@ void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
# define _tr_tally_dist(s, distance, length, flush) \
{ uch len = (uch)(length); \
ush dist = (ush)(distance); \
- s->sym_buf[s->sym_next++] = dist; \
- s->sym_buf[s->sym_next++] = dist >> 8; \
+ s->sym_buf[s->sym_next++] = (uch)dist; \
+ s->sym_buf[s->sym_next++] = (uch)(dist >> 8); \
s->sym_buf[s->sym_next++] = len; \
dist--; \
s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
diff --git a/lib/libvgz/inflate.c b/lib/libvgz/inflate.c
index 9577e8312..5cdbe8b95 100644
--- a/lib/libvgz/inflate.c
+++ b/lib/libvgz/inflate.c
@@ -171,6 +171,8 @@ int windowBits;
/* extract wrap request from windowBits parameter */
if (windowBits < 0) {
+ if (windowBits < -15)
+ return Z_STREAM_ERROR;
wrap = 0;
windowBits = -windowBits;
}
diff --git a/lib/libvgz/inftrees.c b/lib/libvgz/inftrees.c
index 761253942..2cac3d8be 100644
--- a/lib/libvgz/inftrees.c
+++ b/lib/libvgz/inftrees.c
@@ -63,7 +63,7 @@ unsigned short FAR *work;
35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
static const unsigned short lext[31] = { /* Length codes 257..285 extra */
16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
- 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 199, 202};
+ 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 194, 65};
static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
diff --git a/lib/libvgz/inftrees.h b/lib/libvgz/inftrees.h
index baa53a0b1..f53665311 100644
--- a/lib/libvgz/inftrees.h
+++ b/lib/libvgz/inftrees.h
@@ -38,7 +38,7 @@ typedef struct {
/* Maximum size of the dynamic table. The maximum number of code structures is
1444, which is the sum of 852 for literal/length codes and 592 for distance
codes. These values were found by exhaustive searches using the program
- examples/enough.c found in the zlib distribtution. The arguments to that
+ examples/enough.c found in the zlib distribution. The arguments to that
program are the number of symbols, the initial root table size, and the
maximum bit length of a code. "enough 286 9 15" for literal/length codes
returns returns 852, and "enough 30 6 15" for distance codes returns 592.
diff --git a/lib/libvgz/trees.c b/lib/libvgz/trees.c
index 6ae8dcf47..1ccce63e6 100644
--- a/lib/libvgz/trees.c
+++ b/lib/libvgz/trees.c
@@ -312,7 +312,7 @@ local void tr_static_init()
}
/* ===========================================================================
- * Genererate the file trees.h describing the static trees.
+ * Generate the file trees.h describing the static trees.
*/
#ifdef GEN_TREES_H
# ifndef ZLIB_DEBUG
@@ -807,8 +807,8 @@ local int build_bl_tree(s)
/* Build the bit length tree: */
build_tree(s, (tree_desc *)(&(s->bl_desc)));
- /* opt_len now includes the length of the tree representations, except
- * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+ /* opt_len now includes the length of the tree representations, except the
+ * lengths of the bit lengths codes and the 5 + 5 + 4 bits for the counts.
*/
/* Determine the number of bit length codes to send. The pkzip format
@@ -961,7 +961,10 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
s->sym_next / 3));
- if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
+#ifndef FORCE_STATIC
+ if (static_lenb <= opt_lenb || s->strategy == Z_FIXED)
+#endif
+ opt_lenb = static_lenb;
} else {
Assert(buf != (char*)0, "lost buf");
@@ -982,11 +985,7 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
*/
_tr_stored_block(s, buf, stored_len, last);
-#ifdef FORCE_STATIC
- } else if (static_lenb >= 0) { /* force static trees */
-#else
- } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
-#endif
+ } else if (static_lenb == opt_lenb) {
send_bits(s, (STATIC_TREES<<1)+last, 3);
compress_block(s, (const ct_data *)static_ltree,
(const ct_data *)static_dtree);
@@ -1028,11 +1027,11 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
int ZLIB_INTERNAL _tr_tally (s, dist, lc)
deflate_state *s;
unsigned dist; /* distance of matched string */
- unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
+ unsigned lc; /* match length - MIN_MATCH or unmatched char (dist==0) */
{
- s->sym_buf[s->sym_next++] = dist;
- s->sym_buf[s->sym_next++] = dist >> 8;
- s->sym_buf[s->sym_next++] = lc;
+ s->sym_buf[s->sym_next++] = (uch)dist;
+ s->sym_buf[s->sym_next++] = (uch)(dist >> 8);
+ s->sym_buf[s->sym_next++] = (uch)lc;
if (dist == 0) {
/* lc is the unmatched char */
s->dyn_ltree[lc].Freq++;
@@ -1074,7 +1073,7 @@ local void compress_block(s, ltree, dtree)
} else {
/* Here, lc is the match length - MIN_MATCH */
code = _length_code[lc];
- send_code(s, code+LITERALS+1, ltree); /* send the length code */
+ send_code(s, code + LITERALS + 1, ltree); /* send length code */
extra = extra_lbits[code];
if (extra != 0) {
lc -= base_length[code];
diff --git a/lib/libvgz/vgz.h b/lib/libvgz/vgz.h
index b259aac34..eff35f22a 100644
--- a/lib/libvgz/vgz.h
+++ b/lib/libvgz/vgz.h
@@ -281,7 +281,7 @@ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
== 0), or after each call of deflate(). If deflate returns Z_OK and with
zero avail_out, it must be called again after making room in the output
buffer because there might be more output pending. See deflatePending(),
- which can be used if desired to determine whether or not there is more ouput
+ which can be used if desired to determine whether or not there is more output
in that case.
Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
@@ -665,7 +665,7 @@ ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
to dictionary. dictionary must have enough space, where 32768 bytes is
always enough. If deflateGetDictionary() is called with dictionary equal to
Z_NULL, then only the dictionary length is returned, and nothing is copied.
- Similary, if dictLength is Z_NULL, then it is not set.
+ Similarly, if dictLength is Z_NULL, then it is not set.
deflateGetDictionary() may return a length less than the window size, even
when more than the window size in input has been provided. It may return up
@@ -920,7 +920,7 @@ ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
to dictionary. dictionary must have enough space, where 32768 bytes is
always enough. If inflateGetDictionary() is called with dictionary equal to
Z_NULL, then only the dictionary length is returned, and nothing is copied.
- Similary, if dictLength is Z_NULL, then it is not set.
+ Similarly, if dictLength is Z_NULL, then it is not set.
inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
stream state is inconsistent.
@@ -1442,12 +1442,12 @@ ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
In the event that the end of file is reached and only a partial item is
available at the end, i.e. the remaining uncompressed data length is not a
- multiple of size, then the final partial item is nevetheless read into buf
+ multiple of size, then the final partial item is nevertheless read into buf
and the end-of-file flag is set. The length of the partial item read is not
provided, but could be inferred from the result of gztell(). This behavior
is the same as the behavior of fread() implementations in common libraries,
but it prevents the direct use of gzfread() to read a concurrently written
- file, reseting and retrying on end-of-file, when size is not 1.
+ file, resetting and retrying on end-of-file, when size is not 1.
*/
ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len));
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