zlib 1.1.0

wlggod · Sep 10, 2011 · 965fe72 · 965fe72
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diff --git a/ChangeLog b/ChangeLog
@@ -1,6 +1,17 @@
 
 		ChangeLog file for zlib
 
+Changes in 1.1 (24 Feb 98)
+- do not return STREAM_END prematurely in inflate (John Bowler)
+- revert to the zlib 1.0.8 inflate to avoid the gcc 2.8.0 bug (Jeremy Buhler)
+- compile with -DFASTEST to get compression code optimized for speed only
+- in minigzip, try mmap'ing the input file first (Miguel Albrecht)
+- increase size of I/O buffers in minigzip.c and gzio.c (not a big gain
+  on Sun but significant on HP)
+
+- add a pointer to experimental unzip library in README (Gilles Vollant)
+- initialize variable gcc in configure (Chris Herborth)
+
 Changes in 1.0.9 (17 Feb 1998)
 - added gzputs and gzgets functions
 - do not clear eof flag in gzseek (Mark Diekhans)

diff --git a/Makefile b/Makefile
@@ -23,7 +23,7 @@ CFLAGS=-O
 LDFLAGS=-L. -lz
 LDSHARED=$(CC)
 
-VER=1.0.9
+VER=1.1.0
 LIBS=libz.a
 SHAREDLIB=libz.so
 

diff --git a/Makefile.in b/Makefile.in
@@ -23,7 +23,7 @@ CFLAGS=-O
 LDFLAGS=-L. -lz
 LDSHARED=$(CC)
 
-VER=1.0.9
+VER=1.1.0
 LIBS=libz.a
 SHAREDLIB=libz.so
 

diff --git a/README b/README
@@ -1,4 +1,4 @@
-zlib 1.0.9 is a general purpose data compression library.  All the code
+zlib 1.1.0 is a general purpose data compression library.  All the code
 is thread safe.  The data format used by the zlib library
 is described by RFCs (Request for Comments) 1950 to 1952 in the files 
 ftp://ds.internic.net/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate
@@ -25,21 +25,15 @@ Mark Nelson wrote an article about zlib for the Jan. 1997 issue of
 Dr. Dobb's Journal; a copy of the article is available in
 http://web2.airmail.net/markn/articles/zlibtool/zlibtool.htm
 
-The changes made in version 1.0.9 are documented in the file ChangeLog.
-The main changes since 1.0.8 are:
+The changes made in version 1.1.0 are documented in the file ChangeLog.
+The main changes since 1.0.9 are:
 
-- added gzputs and gzgets functions
-- do not clear eof flag in gzseek (Mark Diekhans)
-- fix gzseek for files in transparent mode (Mark Diekhans)
-- do not assume that vsprintf returns the number of bytes written (Jens Krinke)
-- replace EXPORT with ZEXPORT to avoid conflict with other programs
-- added compress2 in zconf.h, zlib.def, zlib.dnt
-- new asm code from Gilles Vollant in contrib/asm386
-- simplify the inflate code (Mark):
- . Replace ZALLOC's in huft_build() with single ZALLOC in inflate_blocks_new()
- . ZALLOC the length list in inflate_trees_fixed() instead of using stack
- . ZALLOC the value area for huft_build() instead of using stack
- . Simplify Z_FINISH check in inflate()
+- do not return STREAM_END prematurely in inflate (John Bowler)
+- revert to the zlib 1.0.8 inflate to avoid the gcc 2.8.0 bug (Jeremy Buhler)
+- compile with -DFASTEST to get compression code optimized for speed only
+- in minigzip, try mmap'ing the input file first (Miguel Albrecht)
+- increase size of I/O buffers in minigzip.c and gzio.c (not a big gain
+  on Sun but significant on HP)
 
 
 Unsupported third party contributions are provided in directory "contrib".
@@ -56,6 +50,11 @@ A Python interface to zlib written by A.M. Kuchling <amk@magnet.com>
 is available from the Python Software Association sites, such as:
 ftp://ftp.python.org/pub/python/contrib/Encoding/zlib*.tar.gz
 
+An experimental package to read files in .zip format, written on top of
+zlib by Gilles Vollant <info@winimage.com>, is available at
+http://www.winimage.com/zLibDll/unzip.html
+
+
 Notes for some targets:
 
 - To build a Windows DLL version, include in a DLL project zlib.def, zlib.rc
@@ -83,7 +82,7 @@ Notes for some targets:
   writes to pointers are atomic. Also the functions zalloc and zfree passed
   to deflateInit must be multi-threaded in this case.
 
-- gzdopen is not supported on RISCOS, BEOS and Mac
+- gzdopen is not supported on RISCOS, BEOS and by some Mac compilers.
 
 - For Turbo C the small model is supported only with reduced performance to
   avoid any far allocation; it was tested with -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3

diff --git a/configure b/configure
@@ -27,6 +27,7 @@ prefix=${prefix-/usr/local}
 exec_prefix=${exec_prefix-$prefix}
 shared_ext='.so'
 shared=0
+gcc=0
 old_cc="$CC"
 old_cflags="$CFLAGS"
 
@@ -114,7 +115,6 @@ if test $shared -eq 0; then
   LDSHARED="$CC"
   echo Building static library $LIBS version $VER with $CC.
 fi
-rm -f $test.[co] $test$shared_ext
 
 if test -f /usr/include/unistd.h; then
   CFLAGS="$CFLAGS -DHAVE_UNISTD_H"
@@ -124,6 +124,23 @@ if test ! -f /usr/include/errno.h; then
   CFLAGS="$CFLAGS -DNO_ERRNO_H"
 fi
 
+cat > $test.c <<EOF
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+caddr_t hello() {
+  return mmap((caddr_t)0, (off_t)0, PROT_READ, MAP_SHARED, 0, (off_t)0); 
+}
+EOF
+if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
+  CFLAGS="$CFLAGS -DUSE_MMAP"
+  echo Checking for mmap support... Yes.
+else
+  echo Checking for mmap support... No.
+fi
+
+rm -f $test.[co] $test$shared_ext
+
 # udpate Makefile
 sed < Makefile.in "
 /^CC *=/s%=.*%=$CC%

diff --git a/deflate.c b/deflate.c
@@ -52,7 +52,7 @@
 #include "deflate.h"
 
 const char deflate_copyright[] =
-   " deflate 1.0.9 Copyright 1995-1998 Jean-loup Gailly ";
+   " deflate 1.1.0 Copyright 1995-1998 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
@@ -160,14 +160,23 @@ struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
  * Insert string str in the dictionary and set match_head to the previous head
  * of the hash chain (the most recent string with same hash key). Return
  * the previous length of the hash chain.
+ * If this file is compiled with -DFASTEST, the compression level is forced
+ * to 1, and no hash chains are maintained.
  * IN  assertion: all calls to to INSERT_STRING are made with consecutive
  *    input characters and the first MIN_MATCH bytes of str are valid
  *    (except for the last MIN_MATCH-1 bytes of the input file).
  */
+#ifdef FASTEST
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#else
 #define INSERT_STRING(s, str, match_head) \
    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
     s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
     s->head[s->ins_h] = (Pos)(str))
+#endif
 
 /* ===========================================================================
  * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
@@ -224,6 +233,9 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
     if (strm->zfree == Z_NULL) strm->zfree = zcfree;
 
     if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#ifdef FASTEST
+    level = 1;
+#endif
 
     if (windowBits < 0) { /* undocumented feature: suppress zlib header */
         noheader = 1;
@@ -708,6 +720,7 @@ local void lm_init (s)
 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
  * match.S. The code will be functionally equivalent.
  */
+#ifndef FASTEST
 local uInt longest_match(s, cur_match)
     deflate_state *s;
     IPos cur_match;                             /* current match */
@@ -845,6 +858,64 @@ local uInt longest_match(s, cur_match)
     if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
     return s->lookahead;
 }
+
+#else /* FASTEST */
+/* ---------------------------------------------------------------------------
+ * Optimized version for level == 1 only
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                       /* matched string */
+    register int len;                           /* length of current match */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    Assert(cur_match < s->strstart, "no future");
+
+    match = s->window + cur_match;
+
+    /* Return failure if the match length is less than 2:
+     */
+    if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
+
+    /* The check at best_len-1 can be removed because it will be made
+     * again later. (This heuristic is not always a win.)
+     * 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.
+     */
+    scan += 2, match += 2;
+    Assert(*scan == *match, "match[2]?");
+
+    /* We check for insufficient lookahead only every 8th comparison;
+     * the 256th check will be made at strstart+258.
+     */
+    do {
+    } while (*++scan == *++match && *++scan == *++match &&
+	     *++scan == *++match && *++scan == *++match &&
+	     *++scan == *++match && *++scan == *++match &&
+	     *++scan == *++match && *++scan == *++match &&
+	     scan < strend);
+
+    Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+    len = MAX_MATCH - (int)(strend - scan);
+
+    if (len < MIN_MATCH) return MIN_MATCH - 1;
+
+    s->match_start = cur_match;
+    return len <= s->lookahead ? len : s->lookahead;
+}
+#endif /* FASTEST */
 #endif /* ASMV */
 
 #ifdef DEBUG
@@ -930,6 +1001,7 @@ local void fill_window(s)
 	    } while (--n);
 
 	    n = wsize;
+#ifndef FASTEST
 	    p = &s->prev[n];
 	    do {
 		m = *--p;
@@ -938,6 +1010,7 @@ local void fill_window(s)
 		 * its value will never be used.
 		 */
 	    } while (--n);
+#endif
             more += wsize;
         }
         if (s->strm->avail_in == 0) return;
@@ -1105,14 +1178,15 @@ local block_state deflate_fast(s, flush)
         if (s->match_length >= MIN_MATCH) {
             check_match(s, s->strstart, s->match_start, s->match_length);
 
-            bflush = _tr_tally(s, s->strstart - s->match_start,
-                               s->match_length - MIN_MATCH);
+            _tr_tally_dist(s, s->strstart - s->match_start,
+                           s->match_length - MIN_MATCH, bflush);
 
             s->lookahead -= s->match_length;
 
             /* Insert new strings in the hash table only if the match length
              * is not too large. This saves time but degrades compression.
              */
+#ifndef FASTEST
             if (s->match_length <= s->max_insert_length &&
                 s->lookahead >= MIN_MATCH) {
                 s->match_length--; /* string at strstart already in hash table */
@@ -1124,7 +1198,9 @@ local block_state deflate_fast(s, flush)
                      */
                 } while (--s->match_length != 0);
                 s->strstart++; 
-            } else {
+            } else
+#endif
+	    {
                 s->strstart += s->match_length;
                 s->match_length = 0;
                 s->ins_h = s->window[s->strstart];
@@ -1139,7 +1215,7 @@ local block_state deflate_fast(s, flush)
         } else {
             /* No match, output a literal byte */
             Tracevv((stderr,"%c", s->window[s->strstart]));
-            bflush = _tr_tally (s, 0, s->window[s->strstart]);
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
             s->lookahead--;
             s->strstart++; 
         }
@@ -1219,7 +1295,7 @@ local block_state deflate_slow(s, flush)
             check_match(s, s->strstart-1, s->prev_match, s->prev_length);
 
             bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
-                               s->prev_length - MIN_MATCH);
+			       s->prev_length - MIN_MATCH);
 
             /* Insert in hash table all strings up to the end of the match.
              * strstart-1 and strstart are already inserted. If there is not
@@ -1245,7 +1321,8 @@ local block_state deflate_slow(s, flush)
              * is longer, truncate the previous match to a single literal.
              */
             Tracevv((stderr,"%c", s->window[s->strstart-1]));
-            if (_tr_tally (s, 0, s->window[s->strstart-1])) {
+	    _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+            if (bflush) {
                 FLUSH_BLOCK_ONLY(s, 0);
             }
             s->strstart++;
@@ -1263,7 +1340,7 @@ local block_state deflate_slow(s, flush)
     Assert (flush != Z_NO_FLUSH, "no flush?");
     if (s->match_available) {
         Tracevv((stderr,"%c", s->window[s->strstart-1]));
-        _tr_tally (s, 0, s->window[s->strstart-1]);
+        _tr_tally_lit(s, s->window[s->strstart-1], bflush);
         s->match_available = 0;
     }
     FLUSH_BLOCK(s, flush == Z_FINISH);

diff --git a/deflate.h b/deflate.h
@@ -273,4 +273,46 @@ ulg  _tr_flush_block  OF((deflate_state *s, charf *buf, ulg stored_len,
 void _tr_align        OF((deflate_state *s));
 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
                           int eof));
+
+#define d_code(dist) \
+   ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. _dist_code[256] and _dist_code[257] are never
+ * used.
+ */
+
+#ifndef DEBUG
+/* Inline versions of _tr_tally for speed: */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+  extern uch _length_code[];
+  extern uch _dist_code[];
+#else
+  extern const uch _length_code[];
+  extern const uch _dist_code[];
+#endif
+
+# define _tr_tally_lit(s, c, flush) \
+  { uch cc = (c); \
+    s->d_buf[s->last_lit] = 0; \
+    s->l_buf[s->last_lit++] = cc; \
+    s->dyn_ltree[cc].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+   }
+# define _tr_tally_dist(s, distance, length, flush) \
+  { uch len = (length); \
+    ush dist = (distance); \
+    s->d_buf[s->last_lit] = dist; \
+    s->l_buf[s->last_lit++] = len; \
+    dist--; \
+    s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
+    s->dyn_dtree[d_code(dist)].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+  }
+#else
+# define _tr_tally_lit(s, c, flush) _tr_tally(s, 0, c, flush)
+# define _tr_tally_dist(s, distance, length, flush) \
+              _tr_tally(s, distance, length, flush) 
+#endif
+
 #endif