From a8d0870c6e9c9d2269c2b856cd2d83949fef4154 Mon Sep 17 00:00:00 2001

From: Daniel van Vugt <daniel.van.vugt@canonical.com>

Date: Tue, 7 May 2019 18:08:13 +0800

Subject: [PATCH 1/2] compositor: Don't emit size-changed when only position

 changes

Waking up gnome-shell and triggering JavaScript listeners of

`size-changed` every time a window was only moved was wasting a lot

of CPU.

This cuts the CPU requirement for dragging windows by around 22%.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/568

---

 src/compositor/compositor.c                |  8 +++-

 src/compositor/meta-window-actor-private.h | 12 +++++-

 src/compositor/meta-window-actor.c         | 43 ++++++++++++++++++----

 3 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/src/compositor/compositor.c b/src/compositor/compositor.c

index 8c924d256..abf7de57d 100644

--- a/src/compositor/compositor.c

+++ b/src/compositor/compositor.c

@@ -1070,8 +1070,12 @@ meta_compositor_sync_window_geometry (MetaCompositor *compositor,

                                       gboolean did_placement)

 {

   MetaWindowActor *window_actor = META_WINDOW_ACTOR (meta_window_get_compositor_private (window));

-  meta_window_actor_sync_actor_geometry (window_actor, did_placement);

-  meta_plugin_manager_event_size_changed (compositor->plugin_mgr, window_actor);

+  MetaWindowActorChanges changes;

+

+  changes = meta_window_actor_sync_actor_geometry (window_actor, did_placement);

+

+  if (changes & META_WINDOW_ACTOR_CHANGE_SIZE)

+    meta_plugin_manager_event_size_changed (compositor->plugin_mgr, window_actor);

 }

 static void

diff --git a/src/compositor/meta-window-actor-private.h b/src/compositor/meta-window-actor-private.h

index ce5e7eadc..acd649d07 100644

--- a/src/compositor/meta-window-actor-private.h

+++ b/src/compositor/meta-window-actor-private.h

@@ -12,6 +12,12 @@

 MetaWindowActor *meta_window_actor_new (MetaWindow *window);

+typedef enum

+{

+  META_WINDOW_ACTOR_CHANGE_SIZE     = 1 << 0,

+  META_WINDOW_ACTOR_CHANGE_POSITION = 1 << 1

+} MetaWindowActorChanges;

+

 void meta_window_actor_queue_destroy   (MetaWindowActor *self);

 void meta_window_actor_show (MetaWindowActor *self,

@@ -43,8 +49,10 @@ void     meta_window_actor_set_unredirected    (MetaWindowActor *self,

                                                 gboolean         unredirected);

 gboolean meta_window_actor_effect_in_progress  (MetaWindowActor *self);

-void     meta_window_actor_sync_actor_geometry (MetaWindowActor *self,

-                                                gboolean         did_placement);

+

+MetaWindowActorChanges meta_window_actor_sync_actor_geometry (MetaWindowActor *self,

+                                                              gboolean         did_placement);

+

 void     meta_window_actor_update_shape        (MetaWindowActor *self);

 void     meta_window_actor_update_opacity      (MetaWindowActor *self);

 void     meta_window_actor_mapped              (MetaWindowActor *self);

diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c

index 120b0432c..afe2bab6e 100644

--- a/src/compositor/meta-window-actor.c

+++ b/src/compositor/meta-window-actor.c

@@ -1299,12 +1299,14 @@ meta_window_actor_queue_destroy (MetaWindowActor *self)

     clutter_actor_destroy (CLUTTER_ACTOR (self));

 }

-void

+MetaWindowActorChanges

 meta_window_actor_sync_actor_geometry (MetaWindowActor *self,

                                        gboolean         did_placement)

 {

   MetaWindowActorPrivate *priv = self->priv;

   MetaRectangle window_rect;

+  ClutterActor *actor = CLUTTER_ACTOR (self);

+  MetaWindowActorChanges changes = 0;

   meta_window_get_buffer_rect (priv->window, &window_rect);

@@ -1322,15 +1324,42 @@ meta_window_actor_sync_actor_geometry (MetaWindowActor *self,

    * updates.

    */

   if (is_frozen (self) && !did_placement)

-    return;

+    return META_WINDOW_ACTOR_CHANGE_POSITION | META_WINDOW_ACTOR_CHANGE_SIZE;

   if (meta_window_actor_effect_in_progress (self))

-    return;

+    return META_WINDOW_ACTOR_CHANGE_POSITION | META_WINDOW_ACTOR_CHANGE_SIZE;

+

+  if (clutter_actor_has_allocation (actor))

+    {

+      ClutterActorBox box;

+      float old_x, old_y;

+      float old_width, old_height;

+

+      clutter_actor_get_allocation_box (actor, &box);

+

+      old_x = box.x1;

+      old_y = box.y1;

+      old_width = box.x2 - box.x1;

+      old_height = box.y2 - box.y1;

+

+      if (old_x != window_rect.x || old_y != window_rect.y)

+        changes |= META_WINDOW_ACTOR_CHANGE_POSITION;

+

+      if (old_width != window_rect.width || old_height != window_rect.height)

+        changes |= META_WINDOW_ACTOR_CHANGE_SIZE;

+    }

+  else

+    {

+      changes = META_WINDOW_ACTOR_CHANGE_POSITION | META_WINDOW_ACTOR_CHANGE_SIZE;

+    }

+

+  if (changes & META_WINDOW_ACTOR_CHANGE_POSITION)

+    clutter_actor_set_position (actor, window_rect.x, window_rect.y);

+

+  if (changes & META_WINDOW_ACTOR_CHANGE_SIZE)

+    clutter_actor_set_size (actor, window_rect.width, window_rect.height);

-  clutter_actor_set_position (CLUTTER_ACTOR (self),

-                              window_rect.x, window_rect.y);

-  clutter_actor_set_size (CLUTTER_ACTOR (self),

-                          window_rect.width, window_rect.height);

+  return changes;

 }

 void

-- 

2.21.0