babl: adjust search depth for fishes in first pass

Search first only to a depth of 2, and accept the fastest found if any
faster than reference is found, if not search to depth 5. We lose out in
the unlikely to be frequent cases where 2-step babl fishes exist and a 3
step fish is faster. And gain the fishes where 4 step is faster than 3
(which was the old first pass search depth).

diff --git a/babl/babl-fish-path.c b/babl/babl-fish-path.c
index e4916696322c99932015d487b5cfeaecc117d00d..7a55d4449e7a7b10b7c9d763d51c3ac52e8a1c06 100644 (file)
--- a/babl/babl-fish-path.c
+++ b/babl/babl-fish-path.c
@@ -145,11 +145,12 @@ max_path_length (void)
   if (env)
     max_length = atoi (env);
   else
-    max_length = 3; /* reducing this number makes finding short fishes much
+    max_length = 2; /* reducing this number makes finding short fishes much
                        faster - even if we lose out on some of the fast
-                       bigger fish, the fishes we can get with a max_length of 3
-                       is actually 5, since we deepen the search twice if no
-                       sufficient results are found.
+                       bigger fish, the fishes we can get with a max_length of 2
+                       is actually 5, since we deepen the search to that
+                       depth if none are found within two steps in the
+                       initial search.
                      */
   if (max_length > BABL_HARD_MAX_PATH_LENGTH)
     max_length = BABL_HARD_MAX_PATH_LENGTH;
@@ -602,35 +603,15 @@ babl_fish_path2 (const Babl *source,
 
     get_conversion_path (&pc, (Babl *) source, 0, max_path_length (), tolerance);
 
-#if 0
-    /* second attempt,. at path length + 1*/
-    if (babl->fish_path.conversion_list->count == 0 &&
-        max_path_length () + 1 <= BABL_HARD_MAX_PATH_LENGTH)
+    /* attempt with path length + 3 */
+    if (babl->fish_path.conversion_list->count == 0)
     {
-      get_conversion_path (&pc, (Babl *) source, 0, max_path_length () + 1, tolerance);
+      int max_length = max_path_length () + 3;
+      if  (max_length > BABL_HARD_MAX_PATH_LENGTH)
+        max_length = BABL_HARD_MAX_PATH_LENGTH;
 
-#if 0
-      if (babl->fish_path.conversion_list->count)
-      {
-        fprintf (stderr, "babl is using a rather long chain, room exists for optimization here\n");
-        babl_list_each (babl->fish_path.conversion_list, show_item, NULL);
-      }
-#endif
-    }
-#endif
-
-    /* third attempt,. at path length + 2 */
-    if (babl->fish_path.conversion_list->count == 0 &&
-        max_path_length () + 2 <= BABL_HARD_MAX_PATH_LENGTH)
-    {
-      get_conversion_path (&pc, (Babl *) source, 0, max_path_length () + 2, tolerance);
-#if 1
-      if (babl->fish_path.conversion_list->count)
-      {
-        //fprintf (stderr, "babl is a long chain, should be optimized\n");
-        //babl_list_each (babl->fish_path.conversion_list, show_item, NULL);
-      }
-      else
+      get_conversion_path (&pc, (Babl *) source, 0, max_length, tolerance);
+      if (!babl->fish_path.conversion_list->count)
       {
          static int show_missing = -1;
          if (show_missing < 0)
@@ -645,7 +626,6 @@ babl_fish_path2 (const Babl *source,
            fprintf (stderr, "babl is lacking conversion for %s to %s\n",
                babl_get_name (source), babl_get_name (destination));
       }
-#endif
     }
 
     babl_in_fish_path--;