Performance improvements: rather than calling content_clean() every poll, we now call it no more frequently than once every 5 seconds. Additionally, we cache the result of talloc_total_size() in content_clean() rather than calculating it twice. On large documents, this function took 25% of CPU time. This makes the fetching/rendering/scrolling/redrawing of large documents over twice as fast.

svn path=/trunk/netsurf/; revision=4527

content/content.c

@@ -873,14 +873,15 @@ void content_clean(void)
 	next = 0;
 	for (c = content_list; c; c = c->next) {
 		next = c;
-		size += c->size + talloc_total_size(c);
+		c->talloc_size = talloc_total_size(c);
+		size += c->size + c->talloc_size;
 	}
 	for (c = next; c && (unsigned int) option_memory_cache_size < size;
 			c = prev) {
 		prev = c->prev;
 		if (c->user_list->next)
 			continue;
-		size -= c->size + talloc_total_size(c);
+		size -= c->size + c->talloc_size;
 		content_destroy(c);
 	}
 }

content/content.h

@@ -232,6 +232,7 @@ struct content {
 	unsigned int size;		/**< Estimated size of all data
 					  associated with this content, except
 					  alloced as talloc children of this. */
+	off_t talloc_size;		/**< Used by content_clean() */
 	char *title;			/**< Title for browser window. */
 	unsigned int active;		/**< Number of child fetches or
 					  conversions currently in progress. */

desktop/netsurf.c

@@ -121,7 +121,16 @@ void netsurf_init(int argc, char** argv)
 
 void netsurf_poll(void)
 {
-	content_clean();
+	static unsigned int last_clean = 0;
+	unsigned int current_time = wallclock();
+
+	/* avoid calling content_clean() more often than once every 5
+	 * seconds.
+	 */
+	if (last_clean + 500 < current_time) {
+		last_clean = current_time;
+		content_clean();
+	}
 	gui_poll(fetch_active);
 	fetch_poll();
 }