[gnome-shell] Use pre-split element classes and pseudo-classes to optimize matching

[Simon McVittie <smcv src gnome org>]

commit 5ae2f87ce9edc6b5ad4746eed6f08e35587df0fc
Author: Simon McVittie <simon mcvittie collabora co uk>
Date:   Thu Nov 8 15:41:31 2012 +0000

    Use pre-split element classes and pseudo-classes to optimize matching
    
    In my testing this cuts the longest time to dispatch(), when showing the
    calendar menu for the first time, from 604 to 442 milliseconds,
    while reducing additional_selector_matches_style() from 32% to 13% of
    CPU time used.
    
    Bug: https://bugzilla.gnome.org/show_bug.cgi?id=687465
    Reviewed-by: Jasper St. Pierre <jstpierre mecheye net>

 src/st/st-theme.c |   45 +++++++++++++++++----------------------------
 1 files changed, 17 insertions(+), 28 deletions(-)
---
diff --git a/src/st/st-theme.c b/src/st/st-theme.c
index 298cdc8..4012ab9 100644
--- a/src/st/st-theme.c
+++ b/src/st/st-theme.c
@@ -448,28 +448,20 @@ st_theme_new (const char       *application_stylesheet,
 
 static gboolean
 string_in_list (GString    *stryng,
-                const char *list)
+                GStrv       list)
 {
-  char *cur;
-  char *l = g_strdup (list);
-  char *temp;
-  gboolean found = FALSE;
+  gchar **it;
 
-  cur = strtok_r (l, " \t\f\r\n", &temp);
-  while (cur != NULL)
-    {
-      if (!strqcmp (cur, stryng->str, stryng->len))
-        {
-          found = TRUE;
-          goto out;
-        }
+  if (list == NULL)
+    return FALSE;
 
-      cur = strtok_r (NULL, " \t\f\r\n", &temp);
+  for (it = list; *it != NULL; it++)
+    {
+      if (!strqcmp (*it, stryng->str, stryng->len))
+        return TRUE;
     }
 
- out:
-  g_free (l);
-  return found;
+  return FALSE;
 }
 
 static gboolean
@@ -477,7 +469,7 @@ pseudo_class_add_sel_matches_style (StTheme         *a_this,
                                     CRAdditionalSel *a_add_sel,
                                     StThemeNode     *a_node)
 {
-  const char *node_pseudo_class;
+  GStrv node_pseudo_classes;
 
   g_return_val_if_fail (a_this
                         && a_add_sel
@@ -487,12 +479,10 @@ pseudo_class_add_sel_matches_style (StTheme         *a_this,
                         && a_add_sel->content.pseudo->name->stryng->str
                         && a_node, FALSE);
 
-  node_pseudo_class = st_theme_node_get_pseudo_class (a_node);
-
-  if (node_pseudo_class == NULL)
-    return FALSE;
+  node_pseudo_classes = st_theme_node_get_pseudo_classes (a_node);
 
-  return string_in_list (a_add_sel->content.pseudo->name->stryng, node_pseudo_class);
+  return string_in_list (a_add_sel->content.pseudo->name->stryng,
+                         node_pseudo_classes);
 }
 
 /**
@@ -507,7 +497,7 @@ static gboolean
 class_add_sel_matches_style (CRAdditionalSel *a_add_sel,
                              StThemeNode     *a_node)
 {
-  const char *element_class;
+  GStrv element_classes;
 
   g_return_val_if_fail (a_add_sel
                         && a_add_sel->type == CLASS_ADD_SELECTOR
@@ -516,11 +506,10 @@ class_add_sel_matches_style (CRAdditionalSel *a_add_sel,
                         && a_add_sel->content.class_name->stryng->str
                         && a_node, FALSE);
 
-  element_class = st_theme_node_get_element_class (a_node);
-  if (element_class == NULL)
-    return FALSE;
+  element_classes = st_theme_node_get_element_classes (a_node);
 
-  return string_in_list (a_add_sel->content.class_name->stryng, element_class);
+  return string_in_list (a_add_sel->content.class_name->stryng,
+                         element_classes);
 }
 
 /*