Setup hash functions to be switched based on compression level.

diff --git a/deflate.c b/deflate.c
index 466e6e9bb34504f675e19abd0687981d2ee4b17b..e361b38393a7d865c8ec56fc03e1de0f3800a0e7 100644 (file)
--- a/deflate.c
+++ b/deflate.c
@@ -113,6 +113,7 @@ Z_INTERNAL block_state deflate_medium(deflate_state *s, int flush);
 Z_INTERNAL block_state deflate_slow  (deflate_state *s, int flush);
 Z_INTERNAL block_state deflate_rle   (deflate_state *s, int flush);
 Z_INTERNAL block_state deflate_huff  (deflate_state *s, int flush);
+static void lm_set_level         (deflate_state *s, int level);
 static void lm_init              (deflate_state *s);
 Z_INTERNAL unsigned read_buf  (PREFIX3(stream) *strm, unsigned char *buf, unsigned size);
 
@@ -602,11 +603,8 @@ int32_t Z_EXPORT PREFIX(deflateParams)(PREFIX3(stream) *strm, int32_t level, int
             }
             s->matches = 0;
         }
-        s->level = level;
-        s->max_lazy_match   = configuration_table[level].max_lazy;
-        s->good_match       = configuration_table[level].good_length;
-        s->nice_match       = configuration_table[level].nice_length;
-        s->max_chain_length = configuration_table[level].max_chain;
+
+        lm_set_level(s, level);
     }
     s->strategy = strategy;
     return Z_OK;
@@ -1140,6 +1138,22 @@ Z_INTERNAL unsigned read_buf(PREFIX3(stream) *strm, unsigned char *buf, unsigned
     return len;
 }
 
+/* ===========================================================================
+ * Set longest match variables based on level configuration
+ */
+static void lm_set_level(deflate_state *s, int level) {
+    s->max_lazy_match   = configuration_table[level].max_lazy;
+    s->good_match       = configuration_table[level].good_length;
+    s->nice_match       = configuration_table[level].nice_length;
+    s->max_chain_length = configuration_table[level].max_chain;
+
+    s->update_hash = functable.update_hash;
+    s->insert_string = functable.insert_string;
+    s->quick_insert_string = functable.quick_insert_string;
+
+    s->level = level;
+}
+
 /* ===========================================================================
  * Initialize the "longest match" routines for a new zlib stream
  */
@@ -1150,10 +1164,7 @@ static void lm_init(deflate_state *s) {
 
     /* Set the default configuration parameters:
      */
-    s->max_lazy_match   = configuration_table[s->level].max_lazy;
-    s->good_match       = configuration_table[s->level].good_length;
-    s->nice_match       = configuration_table[s->level].nice_length;
-    s->max_chain_length = configuration_table[s->level].max_chain;
+    lm_set_level(s, s->level);
 
     s->strstart = 0;
     s->block_start = 0;
@@ -1227,7 +1238,7 @@ void Z_INTERNAL fill_window(deflate_state *s) {
         if (s->lookahead + s->insert >= STD_MIN_MATCH) {
             unsigned int str = s->strstart - s->insert;
             if (str >= 1)
-                functable.quick_insert_string(s, str + 2 - STD_MIN_MATCH);
+                s->quick_insert_string(s, str + 2 - STD_MIN_MATCH);
             unsigned int count;
             if (UNLIKELY(s->lookahead == 1)) {
                 count = s->insert - 1;
@@ -1235,7 +1246,7 @@ void Z_INTERNAL fill_window(deflate_state *s) {
                 count = s->insert;
             }
             if (count > 0) {
-                functable.insert_string(s, str, count);
+                s->insert_string(s, str, count);
                 s->insert -= count;
             }
         }

diff --git a/deflate.h b/deflate.h
index 808060a385965b66295601fdef3a5a3680df1578..0a50afe23a482470693772c24156ec4129810d6f 100644 (file)
--- a/deflate.h
+++ b/deflate.h
@@ -99,8 +99,14 @@ typedef uint16_t Pos;
 /* A Pos is an index in the character window. We use short instead of int to
  * save space in the various tables.
  */
+/* Type definitions for hash callbacks */
+typedef struct internal_state deflate_state;
 
-typedef struct internal_state {
+typedef uint32_t (* update_hash_cb)        (deflate_state *const s, uint32_t h, uint32_t val);
+typedef void     (* insert_string_cb)      (deflate_state *const s, uint32_t str, uint32_t count);
+typedef Pos      (* quick_insert_string_cb)(deflate_state *const s, uint32_t str);
+
+struct internal_state {
     PREFIX3(stream)      *strm;            /* pointer back to this zlib stream */
     unsigned char        *pending_buf;     /* output still pending */
     unsigned char        *pending_out;     /* next pending byte to output to the stream */
@@ -188,6 +194,12 @@ typedef struct internal_state {
      * max_insert_length is used only for compression levels <= 3.
      */
 
+    update_hash_cb          update_hash;
+    insert_string_cb        insert_string;
+    quick_insert_string_cb  quick_insert_string;
+    /* Hash function callbacks that can be configured depending on the deflate
+     * algorithm being used */
+
     int level;    /* compression level (1..9) */
     int strategy; /* favor or force Huffman coding*/
 
@@ -269,7 +281,7 @@ typedef struct internal_state {
 
     /* Reserved for future use and alignment purposes */
     int32_t reserved[11];
-} ALIGNED_(8) deflate_state;
+} ALIGNED_(8);
 
 typedef enum {
     need_more,      /* block not completed, need more input or more output */

diff --git a/deflate_slow.c b/deflate_slow.c
index ac7e87ee50bd37bf85799278df643d87f6e330bf..0cb40f5ca0801689a8500284a8b1ebc67ca330e6 100644 (file)
--- a/deflate_slow.c
+++ b/deflate_slow.c
@@ -41,7 +41,7 @@ Z_INTERNAL block_state deflate_slow(deflate_state *s, int flush) {
          */
         hash_head = 0;
         if (LIKELY(s->lookahead >= WANT_MIN_MATCH)) {
-            hash_head = functable.quick_insert_string(s, s->strstart);
+            hash_head = s->quick_insert_string(s, s->strstart);
         }
 
         /* Find the longest match, discarding those <= prev_length.
@@ -88,8 +88,7 @@ Z_INTERNAL block_state deflate_slow(deflate_state *s, int flush) {
                 unsigned int insert_cnt = mov_fwd;
                 if (UNLIKELY(insert_cnt > max_insert - s->strstart))
                     insert_cnt = max_insert - s->strstart;
-
-                functable.insert_string(s, s->strstart + 1, insert_cnt);
+                s->insert_string(s, s->strstart + 1, insert_cnt);
             }
             s->prev_length = 0;
             s->match_available = 0;