From 4d2813d3e980c8e6150caafa604a78cc44bf62a2 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 16 Apr 2013 21:57:21 -0400
Subject: [PATCH] Print set-digest hit ratio with HB_DEBUG_SET_DIGESTS

---
 src/hb-set-private.hh | 13 +++++++++++++
 src/hb-set.cc         | 13 +++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/src/hb-set-private.hh b/src/hb-set-private.hh
index 1241e05..d9e0d29 100644
--- a/src/hb-set-private.hh
+++ b/src/hb-set-private.hh
@@ -102,6 +102,10 @@ struct hb_set_digest_lowest_bits_t
   mask_t mask;
 };
 
+#ifdef HB_DEBUG_SET_DIGESTS
+extern unsigned long digest_total, digest_yes, digest_yes1, digest_yes2;
+#endif
+
 struct hb_set_digest_t
 {
   ASSERT_POD ();
@@ -122,6 +126,15 @@ struct hb_set_digest_t
   }
 
   inline bool may_have (hb_codepoint_t g) const {
+#ifdef HB_DEBUG_SET_DIGESTS
+    digest_total++;
+    if (digest1.may_have (g) && digest2.may_have (g))
+      digest_yes++;
+    if (digest1.may_have (g))
+      digest_yes1++;
+    if (digest2.may_have (g))
+      digest_yes2++;
+#endif
     return digest1.may_have (g) && digest2.may_have (g);
   }
 
diff --git a/src/hb-set.cc b/src/hb-set.cc
index 5f427a5..050cc24 100644
--- a/src/hb-set.cc
+++ b/src/hb-set.cc
@@ -27,6 +27,19 @@
 #include "hb-set-private.hh"
 
 
+#ifdef HB_DEBUG_SET_DIGESTS
+unsigned long digest_total, digest_yes, digest_yes1, digest_yes2;
+__attribute__((__destructor__))
+void digest_print (void)
+{
+  if (!digest_total)
+    return;
+  printf("Set digest summary: both %%%ld first %%%ld second %%%ld\n",
+	 100 * digest_yes / digest_total,
+	 100 * digest_yes1 / digest_total,
+	 100 * digest_yes2 / digest_total);
+}
+#endif
 
 /* Public API */
 
-- 
2.7.4