added info

[proxmark3-svn] / zlib / deflate.c

diff --git a/zlib/deflate.c b/zlib/deflate.c
index 7c22a72b4c6ecebc7859ee10e810f8308c3dd36c..8e9a3e653356d55bf6b630fbb64e67ee56b131b8 100644 (file)
--- a/zlib/deflate.c
+++ b/zlib/deflate.c
@@ -52,7 +52,7 @@
 #include "deflate.h"
 
 const char deflate_copyright[] =
-   " deflate 1.2.8 Copyright 1995-2013 Jean-loup Gailly and Mark Adler ";
+   " deflate 1.2.8.f-Proxmark3 Copyright 1995-2013 Jean-loup Gailly and Mark Adler ";
 /*
   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
@@ -60,6 +60,15 @@ const char deflate_copyright[] =
   copyright string in the executable of your product.
  */
 
+//-----------------------------------------------------------------------------
+// This version of zlib is modified for use within the Proxmark3 project. 
+// Files from the original distribution which are not required for this
+// purpose are not included. All modifications can easily be found
+// by searching for #ifdef ZLIB_PM3_TUNED and #ifndef ZLIB_PM3_TUNED.
+//-----------------------------------------------------------------------------
+
+
+ 
 /* ===========================================================================
  *  Function prototypes.
  */
@@ -1727,12 +1736,11 @@ local block_state deflate_fast(s, flush)
 
 
 #ifdef ZLIB_PM3_TUNED
-local uInt try_harder(s, strstart, lookahead, hash_head, level)
+local uInt try_harder(s, strstart, lookahead, hash_head)
        deflate_state *s;
        uInt strstart;
        uInt lookahead;
        IPos hash_head;
-       uInt level;
 {
        uInt strstart_save = s->strstart;
        s->strstart = strstart;
@@ -1768,22 +1776,11 @@ local uInt try_harder(s, strstart, lookahead, hash_head, level)
                } else {
                        combined_gain = s->strstart - strstart + 1 - MIN_MATCH;  // (possibly truncated) previous_length - 3 literals
                }
-               if (level > 1 && s->strstart+1 <= s->window_size - MIN_LOOKAHEAD) {     // test one level more
-                       s->prev_length = match_length;
-                       uInt save_ins_h = s->ins_h;
-                       UPDATE_HASH(s, s->ins_h, s->window[(s->strstart+1) + (MIN_MATCH-1)]);
-                       combined_gain += try_harder(s, s->strstart+1, s->lookahead-1, s->head[s->ins_h], level-1);
-                       s->ins_h = save_ins_h;
+               if (match_length < MIN_MATCH) { 
+                       combined_gain += 0;                                                     // no gain
                } else {
-                       if (match_length < MIN_MATCH) { 
-                               combined_gain += 0;                                                     // no gain
-                       } else {
-                               combined_gain += match_length - MIN_MATCH;      // match_length bytes coded as approx three literals
-                       }
+                       combined_gain += match_length - MIN_MATCH;      // match_length bytes are coded as three literals
                }
-               // if (combined_length > s->lookahead - 1) {
-                       // combined_length = s->lookahead;
-               // }
                if (combined_gain >= best_combined_gain) {                      // in case of a tie we prefer the longer prev_length
                        best_combined_gain = combined_gain;
                        best_prev_length = s->strstart - strstart + 1;
@@ -1792,12 +1789,6 @@ local uInt try_harder(s, strstart, lookahead, hash_head, level)
                s->lookahead--;
                UPDATE_HASH(s, s->ins_h, s->window[(s->strstart) + (MIN_MATCH-1)]);
                hash_head = s->head[s->ins_h];
-               // if (s->strstart - strstart + 1 == MIN_MATCH-1) {             // a match with length == 2 is not possible
-                       // s->strstart++;
-                       // s->lookahead--;
-                       // UPDATE_HASH(s, s->ins_h, s->window[(s->strstart) + (MIN_MATCH-1)]);
-                       // hash_head = s->head[s->ins_h];
-               // }
        } while (s->strstart <= strstart-1 + prev_length                        // try to truncate the previous match to 1, 3, ... prev_length
                        && s->strstart <= s->window_size - MIN_LOOKAHEAD);      // watch out for the end of the input
        
@@ -1806,11 +1797,6 @@ local uInt try_harder(s, strstart, lookahead, hash_head, level)
        s->ins_h = ins_h_save;
        s->match_length = current_match_length;
        s->match_start = current_match_start;
-       if (prev_length >= MIN_MATCH) {
-               if (best_prev_length != prev_length && best_prev_length >= MIN_MATCH) {
-                       printf("at %d, level %d: Reducing prev_length from %d to %d\n", s->strstart, level, prev_length, best_prev_length);
-               }
-       }
        if (best_prev_length >= MIN_MATCH) {
                s->prev_length = best_prev_length;
                s->match_length = MIN_MATCH - 1;
@@ -1865,7 +1851,7 @@ local block_state deflate_slow(s, flush)
 
 #ifdef ZLIB_PM3_TUNED
                if (s->prev_length < s->max_lazy_match) {
-                       try_harder(s, s->strstart, s->lookahead, hash_head, 1);
+                       try_harder(s, s->strstart, s->lookahead, hash_head);
                }
 
 #else