[gimp] Bug 735810 - performance shrinkage of Paths tool

[Michael Natterer <mitch src gnome org>]

commit 4920033c4287924d0dec28cc916907a080d91dbd
Author: Michael Natterer <mitch gimp org>
Date:   Sun Jan 24 00:54:48 2016 +0100

    Bug 735810 - performance shrinkage of Paths tool
    
    Use a GQueue instead of a GList in GimpCanvasGroup, so adding items
    takes constant time instead of O(n). Also, removing items was
    traversing the list twice. This should generally speed up tools with
    lots of canvas items.
    
    Also, add a private pointer to the instance struct instead of using a
    GET_PRIVATE() macro.

 app/display/gimpcanvasgroup.c |  100 +++++++++++++++++-----------------------
 app/display/gimpcanvasgroup.h |    8 +++-
 2 files changed, 49 insertions(+), 59 deletions(-)
---
diff --git a/app/display/gimpcanvasgroup.c b/app/display/gimpcanvasgroup.c
index cfd0e51..5abbe9e 100644
--- a/app/display/gimpcanvasgroup.c
+++ b/app/display/gimpcanvasgroup.c
@@ -40,20 +40,13 @@ enum
 };
 
 
-typedef struct _GimpCanvasGroupPrivate GimpCanvasGroupPrivate;
-
 struct _GimpCanvasGroupPrivate
 {
-  GList    *items;
+  GQueue   *items;
   gboolean  group_stroking;
   gboolean  group_filling;
 };
 
-#define GET_PRIVATE(group) \
-        G_TYPE_INSTANCE_GET_PRIVATE (group, \
-                                     GIMP_TYPE_CANVAS_GROUP, \
-                                     GimpCanvasGroupPrivate)
-
 
 /*  local function prototypes  */
 
@@ -115,17 +108,22 @@ gimp_canvas_group_class_init (GimpCanvasGroupClass *klass)
 static void
 gimp_canvas_group_init (GimpCanvasGroup *group)
 {
+  group->priv = G_TYPE_INSTANCE_GET_PRIVATE (group,
+                                             GIMP_TYPE_CANVAS_GROUP,
+                                             GimpCanvasGroupPrivate);
+
+  group->priv->items = g_queue_new ();
 }
 
 static void
 gimp_canvas_group_dispose (GObject *object)
 {
-  GimpCanvasGroupPrivate *private = GET_PRIVATE (object);
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (object);
 
-  if (private->items)
+  if (group->priv->items)
     {
-      g_list_free_full (private->items, (GDestroyNotify) g_object_unref);
-      private->items = NULL;
+      g_queue_free_full (group->priv->items, (GDestroyNotify) g_object_unref);
+      group->priv->items = NULL;
     }
 
   G_OBJECT_CLASS (parent_class)->dispose (object);
@@ -137,15 +135,15 @@ gimp_canvas_group_set_property (GObject      *object,
                                 const GValue *value,
                                 GParamSpec   *pspec)
 {
-  GimpCanvasGroupPrivate *private = GET_PRIVATE (object);
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (object);
 
   switch (property_id)
     {
     case PROP_GROUP_STROKING:
-      private->group_stroking = g_value_get_boolean (value);
+      group->priv->group_stroking = g_value_get_boolean (value);
       break;
     case PROP_GROUP_FILLING:
-      private->group_filling = g_value_get_boolean (value);
+      group->priv->group_filling = g_value_get_boolean (value);
       break;
 
     default:
@@ -160,15 +158,15 @@ gimp_canvas_group_get_property (GObject    *object,
                                 GValue     *value,
                                 GParamSpec *pspec)
 {
-  GimpCanvasGroupPrivate *private = GET_PRIVATE (object);
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (object);
 
   switch (property_id)
     {
     case PROP_GROUP_STROKING:
-      g_value_set_boolean (value, private->group_stroking);
+      g_value_set_boolean (value, group->priv->group_stroking);
       break;
     case PROP_GROUP_FILLING:
-      g_value_set_boolean (value, private->group_filling);
+      g_value_set_boolean (value, group->priv->group_filling);
       break;
 
     default:
@@ -181,31 +179,31 @@ static void
 gimp_canvas_group_draw (GimpCanvasItem *item,
                         cairo_t        *cr)
 {
-  GimpCanvasGroupPrivate *private = GET_PRIVATE (item);
-  GList                  *list;
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (item);
+  GList           *list;
 
-  for (list = private->items; list; list = g_list_next (list))
+  for (list = group->priv->items->head; list; list = g_list_next (list))
     {
       GimpCanvasItem *sub_item = list->data;
 
       gimp_canvas_item_draw (sub_item, cr);
     }
 
-  if (private->group_stroking)
+  if (group->priv->group_stroking)
     _gimp_canvas_item_stroke (item, cr);
 
-  if (private->group_filling)
+  if (group->priv->group_filling)
     _gimp_canvas_item_fill (item, cr);
 }
 
 static cairo_region_t *
 gimp_canvas_group_get_extents (GimpCanvasItem *item)
 {
-  GimpCanvasGroupPrivate *private = GET_PRIVATE (item);
-  cairo_region_t         *region  = NULL;
-  GList                  *list;
+  GimpCanvasGroup *group  = GIMP_CANVAS_GROUP (item);
+  cairo_region_t  *region = NULL;
+  GList           *list;
 
-  for (list = private->items; list; list = g_list_next (list))
+  for (list = group->priv->items->head; list; list = g_list_next (list))
     {
       GimpCanvasItem *sub_item   = list->data;
       cairo_region_t *sub_region = gimp_canvas_item_get_extents (sub_item);
@@ -229,10 +227,10 @@ gimp_canvas_group_hit (GimpCanvasItem *item,
                        gdouble         x,
                        gdouble         y)
 {
-  GimpCanvasGroupPrivate *private = GET_PRIVATE (item);
-  GList                  *list;
+  GimpCanvasGroup *group = GIMP_CANVAS_GROUP (item);
+  GList           *list;
 
-  for (list = private->items; list; list = g_list_next (list))
+  for (list = group->priv->items->head; list; list = g_list_next (list))
     {
       if (gimp_canvas_item_hit (list->data, x, y))
         return TRUE;
@@ -267,21 +265,17 @@ void
 gimp_canvas_group_add_item (GimpCanvasGroup *group,
                             GimpCanvasItem  *item)
 {
-  GimpCanvasGroupPrivate *private;
-
   g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
   g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
   g_return_if_fail (GIMP_CANVAS_ITEM (group) != item);
 
-  private = GET_PRIVATE (group);
-
-  if (private->group_stroking)
+  if (group->priv->group_stroking)
     gimp_canvas_item_suspend_stroking (item);
 
-  if (private->group_filling)
+  if (group->priv->group_filling)
     gimp_canvas_item_suspend_filling (item);
 
-  private->items = g_list_append (private->items, g_object_ref (item));
+  g_queue_push_tail (group->priv->items, g_object_ref (item));
 
   if (_gimp_canvas_item_needs_update (GIMP_CANVAS_ITEM (group)))
     {
@@ -303,21 +297,21 @@ void
 gimp_canvas_group_remove_item (GimpCanvasGroup *group,
                                GimpCanvasItem  *item)
 {
-  GimpCanvasGroupPrivate *private;
+  GList *list;
 
   g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
   g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
 
-  private = GET_PRIVATE (group);
+  list = g_queue_find (group->priv->items, item);
 
-  g_return_if_fail (g_list_find (private->items, item));
+  g_return_if_fail (list != NULL);
 
-  private->items = g_list_remove (private->items, item);
+  g_queue_delete_link (group->priv->items, list);
 
-  if (private->group_stroking)
+  if (group->priv->group_stroking)
     gimp_canvas_item_resume_stroking (item);
 
-  if (private->group_filling)
+  if (group->priv->group_filling)
     gimp_canvas_item_resume_filling (item);
 
   if (_gimp_canvas_item_needs_update (GIMP_CANVAS_ITEM (group)))
@@ -342,13 +336,9 @@ void
 gimp_canvas_group_set_group_stroking (GimpCanvasGroup *group,
                                       gboolean         group_stroking)
 {
-  GimpCanvasGroupPrivate *private;
-
   g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
 
-  private = GET_PRIVATE (group);
-
-  if (private->group_stroking != group_stroking)
+  if (group->priv->group_stroking != group_stroking)
     {
       GList *list;
 
@@ -358,9 +348,9 @@ gimp_canvas_group_set_group_stroking (GimpCanvasGroup *group,
                     "group-stroking", group_stroking ? TRUE : FALSE,
                     NULL);
 
-      for (list = private->items; list; list = g_list_next (list))
+      for (list = group->priv->items->head; list; list = g_list_next (list))
         {
-          if (private->group_stroking)
+          if (group->priv->group_stroking)
             gimp_canvas_item_suspend_stroking (list->data);
           else
             gimp_canvas_item_resume_stroking (list->data);
@@ -374,13 +364,9 @@ void
 gimp_canvas_group_set_group_filling (GimpCanvasGroup *group,
                                      gboolean         group_filling)
 {
-  GimpCanvasGroupPrivate *private;
-
   g_return_if_fail (GIMP_IS_CANVAS_GROUP (group));
 
-  private = GET_PRIVATE (group);
-
-  if (private->group_filling != group_filling)
+  if (group->priv->group_filling != group_filling)
     {
       GList *list;
 
@@ -390,9 +376,9 @@ gimp_canvas_group_set_group_filling (GimpCanvasGroup *group,
                     "group-filling", group_filling ? TRUE : FALSE,
                     NULL);
 
-      for (list = private->items; list; list = g_list_next (list))
+      for (list = group->priv->items->head; list; list = g_list_next (list))
         {
-          if (private->group_filling)
+          if (group->priv->group_filling)
             gimp_canvas_item_suspend_filling (list->data);
           else
             gimp_canvas_item_resume_filling (list->data);
diff --git a/app/display/gimpcanvasgroup.h b/app/display/gimpcanvasgroup.h
index 453dc54..486f35f 100644
--- a/app/display/gimpcanvasgroup.h
+++ b/app/display/gimpcanvasgroup.h
@@ -33,11 +33,15 @@
 #define GIMP_CANVAS_GROUP_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_GROUP, 
GimpCanvasGroupClass))
 
 
-typedef struct _GimpCanvasGroupClass GimpCanvasGroupClass;
+typedef struct _GimpCanvasGroupPrivate GimpCanvasGroupPrivate;
+typedef struct _GimpCanvasGroupClass   GimpCanvasGroupClass;
 
 struct _GimpCanvasGroup
 {
-  GimpCanvasItem  parent_instance;
+  GimpCanvasItem          parent_instance;
+
+  GimpCanvasGroupPrivate *priv;
+
 };
 
 struct _GimpCanvasGroupClass