Dump lookup statistics

Print out numbers of lookups, their size, and
the amount of sharing.

For widget-factory, the numbers are like this:
319 different lookups, 890 total, 18.5022 avg length

For the gtk-demo listbox example, the number are:
58 different lookups, 9742 total, 15.9997 avg length

gtk/gtkcsslookup.c

@@ -66,6 +66,92 @@ gtk_css_lookup_value_unref (GtkCssLookupValue *value)
     gtk_css_lookup_value_free (value);
 }
 
+static GHashTable *lookups;
+
+static gboolean
+gtk_css_lookup_equal (gconstpointer p1,
+                      gconstpointer p2)
+{
+  const GtkCssLookup *l1 = p1;
+  const GtkCssLookup *l2 = p2;
+  int i;
+
+  if (!_gtk_bitmask_equals (l1->set_values, l2->set_values))
+    return FALSE;
+
+  if (l1->values == NULL && l2->values == NULL)
+    return TRUE;
+
+  if (l1->values == NULL || l2->values == NULL)
+    return FALSE;
+
+  if (l1->values->len != l2->values->len)
+    return FALSE;
+
+  for (i = 0; i < l1->values->len; i++)
+    {
+      GtkCssLookupValue *v1 = g_ptr_array_index (l1->values, i);
+      GtkCssLookupValue *v2 = g_ptr_array_index (l2->values, i);
+
+      if (!_gtk_css_value_equal (v1->value, v2->value))
+        return FALSE;
+    }
+
+  return TRUE;
+}
+
+static guint
+gtk_css_lookup_hash (gconstpointer data)
+{
+  const GtkCssLookup *l = data;
+  int i;
+  guint h;
+
+  if (l->values == NULL)
+    return 0;
+
+  h = 0;
+  for (i = 0; i < l->values->len; i++)
+    {
+      GtkCssLookupValue *v = g_ptr_array_index (l->values, i);
+      char *s = _gtk_css_value_to_string (v->value);
+      h += g_str_hash (s);
+      g_free (s);
+    }
+
+  return h;
+}
+
+static gboolean
+dump_lookups (gpointer data)
+{
+  GHashTableIter iter;
+  GtkCssLookup *key;
+  gpointer value;
+  int total = 0;
+  int length = 0;
+
+  g_hash_table_iter_init (&iter, lookups);
+  while (g_hash_table_iter_next (&iter, (gpointer *)&key, (gpointer *)&value))
+    {
+      total += GPOINTER_TO_INT (value);
+      length += GPOINTER_TO_INT (value) * key->values->len;
+    }
+
+  g_print ("lookup stats:\n");
+  g_print ("\t%d different lookups, %d total, %g avg length\n",
+           g_hash_table_size (lookups),
+           total,
+           length / (1.0 * total));
+
+  g_hash_table_iter_init (&iter, lookups);
+  while (g_hash_table_iter_next (&iter, (gpointer *)&key, (gpointer *)&value))
+    g_print ("\t%d\t%d\n", GPOINTER_TO_INT (value), key->values->len);
+  g_print ("\n");
+
+  return G_SOURCE_CONTINUE;
+}
+
 GtkCssLookup *
 gtk_css_lookup_new (void)
 {
@@ -74,12 +160,50 @@ gtk_css_lookup_new (void)
   lookup->ref_count = 1;
   lookup->set_values = _gtk_bitmask_new ();
 
+  if (!lookups)
+    {
+      lookups = g_hash_table_new (gtk_css_lookup_hash, gtk_css_lookup_equal);
+      g_timeout_add (1000, dump_lookups, NULL);
+    }
+
   return lookup;
 }
 
+void
+gtk_css_lookup_register (GtkCssLookup *lookup)
+{
+  gint count;
+
+  count = GPOINTER_TO_INT (g_hash_table_lookup (lookups, lookup));
+  count++;
+
+  if (count == 1)
+    gtk_css_lookup_ref (lookup);
+
+  g_hash_table_insert (lookups, lookup, GINT_TO_POINTER (count));
+}
+
+static void
+gtk_css_lookup_unregister (GtkCssLookup *lookup)
+{
+  gint count;
+
+  count = GPOINTER_TO_INT (g_hash_table_lookup (lookups, lookup));
+  g_assert (count > 0);
+  if (count == 1)
+    g_hash_table_remove (lookups, lookup);
+  else
+    {
+      count--;
+      g_hash_table_insert (lookups, lookup, GINT_TO_POINTER (count));
+    }
+}
+
 static void
 gtk_css_lookup_free (GtkCssLookup *lookup)
 {
+  gtk_css_lookup_unregister (lookup);
+
   _gtk_bitmask_free (lookup->set_values);
   if (lookup->values)
     g_ptr_array_unref (lookup->values);
@@ -105,6 +229,10 @@ gtk_css_lookup_unref (GtkCssLookup *lookup)
 
   lookup->ref_count--;
 
+  if (lookup->ref_count == 1 &&
+      GPOINTER_TO_INT (g_hash_table_lookup (lookups, lookup)) == 1)
+    lookup->ref_count--;
+
   if (lookup->ref_count == 0)
     gtk_css_lookup_free (lookup);
 }

gtk/gtkcsslookupprivate.h

@@ -85,6 +85,8 @@ gtk_css_lookup_get (GtkCssLookup *lookup,
   return NULL;
 } 
 
+void gtk_css_lookup_register (GtkCssLookup *lookup);
+
 G_END_DECLS
 
 #endif /* __GTK_CSS_LOOKUP_PRIVATE_H__ */

gtk/gtkcssstaticstyle.c

@@ -996,6 +996,8 @@ gtk_css_static_style_new_compute (GtkStyleProvider             *provider,
                                    lookup,
                                    change == 0 ? &change : NULL);
 
+      gtk_css_lookup_register (lookup);
+
       if (_gtk_bitmask_is_empty (gtk_css_lookup_get_set_values (lookup)))
         {
           gtk_css_lookup_unref (lookup);