Optimise css_stylesheet_add_rule by the cunning approach of not iterating through a singly linked list to find the end every time we want to insert a rule. This doubles parsing speed.

svn path=/trunk/libcss/; revision=5811

2 files changed, 7 insertions, 9 deletions

diff --git a/src/stylesheet.c b/src/stylesheet.c
index ea3f2a6..0936243 100644
--- a/src/stylesheet.c
+++ b/src/stylesheet.c
@@ -759,8 +759,6 @@ css_error css_stylesheet_rule_append_style(css_stylesheet *sheet,
  */
 css_error css_stylesheet_add_rule(css_stylesheet *sheet, css_rule *rule)
 {
-	css_rule *r;
-
 	if (sheet == NULL || rule == NULL)
 		return CSS_BADPARM;
 
@@ -771,16 +769,15 @@ css_error css_stylesheet_add_rule(css_stylesheet *sheet, css_rule *rule)
 
 	/* Add rule to sheet */
 	sheet->rule_count++;
-	/** \todo this may need optimising */
-	for (r = sheet->rule_list; r != NULL && r->next != NULL; r = r->next)
-		/* do nothing */;
-	if (r == NULL) {
+
+	if (sheet->last_rule == NULL) {
 		rule->prev = rule->next = NULL;
-		sheet->rule_list = rule;
+		sheet->rule_list = sheet->last_rule = rule;
 	} else {
-		r->next = rule;
-		rule->prev = r;
+		sheet->last_rule->next = rule;
+		rule->prev = sheet->last_rule;
 		rule->next = NULL;
+		sheet->last_rule = rule;
 	}
 
 	/** \todo If there are selectors in the rule, add them to the hash 
diff --git a/src/stylesheet.h b/src/stylesheet.h
index 2156b8e..a331299 100644
--- a/src/stylesheet.h
+++ b/src/stylesheet.h
@@ -142,6 +142,7 @@ struct css_stylesheet {
 
 	uint32_t rule_count;			/**< Number of rules in sheet */
 	css_rule *rule_list;			/**< List of rules in sheet */
+	css_rule *last_rule;			/**< Last rule in list */
 
 	bool disabled;				/**< Whether this sheet is 
 						 * disabled */