1 files changed, 85 insertions, 8 deletions

diff --git a/deflate.c b/deflate.c
index e9c14d7..dc60299 100644
--- 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);