Add FcPreprocessFamily speeding up FcCompareFamliy.

FcPreprocessString calculates hash of the family string to fast reject not matching families.

TODO: Add benchmark numbers.

src/fcmatch.c

@@ -88,20 +88,37 @@ FcCompareString (const FcValue *v1,
     return (double) FcStrCmpIgnoreCase (FcValueString(v1), FcValueString(v2)) != 0;
 }
 
+static FcPrepValue
+FcPreprocessFamily (FcValue *v)
+{
+    FcPrepValue prep;
+    prep.type = FcPrepStrHashIgnoreBlanksAndCase;
+    prep.str_hash = FcStrHashIgnoreBlanksAndCase(FcValueString(v));
+    return prep;
+}
+
 static double
 FcCompareFamily (const FcValue *v1,
 		    const FcPrepValue *p1,
 			const FcValue *v2,
 			const FcPrepValue *p2,
 			FcValue *bestValue)
 {
+    *bestValue = FcValueCanonicalize (v2);
+
+    if (p1->type == FcPrepStrHashIgnoreBlanksAndCase &&
+	p2->type == FcPrepStrHashIgnoreBlanksAndCase)
+    {
+	// If hashes are not matching, return fast
+	if (p1->str_hash != p2->str_hash)
+	    return 1.0;
+    }
+
     /* rely on the guarantee in FcPatternObjectAddWithBinding that
      * families are always FcTypeString. */
     const FcChar8* v1_string = FcValueString(v1);
     const FcChar8* v2_string = FcValueString(v2);
 
-    *bestValue = FcValueCanonicalize (v2);
-
     if (FcToLower(*v1_string) != FcToLower(*v2_string) &&
 	*v1_string != ' ' && *v2_string != ' ')
        return 1.0;

src/fcobjs.h

@@ -22,7 +22,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 /* DON'T REORDER!  The order is part of the cache signature. */
-FC_OBJECT (FAMILY,		FcTypeString,	FcCompareFamily,	NULL)
+FC_OBJECT (FAMILY,		FcTypeString,	FcCompareFamily,	FcPreprocessFamily)
 FC_OBJECT (FAMILYLANG,		FcTypeString,	NULL,			NULL)
 FC_OBJECT (STYLE,		FcTypeString,	FcCompareString,	FcPreprocessString)
 FC_OBJECT (STYLELANG,		FcTypeString,	NULL,			NULL)