[PATCH v2 5/6] composite: Support updating an arbitrary subtree

[ville.syrjala at nokia.com]

From: Ville Syrjälä <ville.syrjala at nokia.com>

Rename compScreenUpdate to compChildrenUpdate, and pass a window as
the parameter. This allows an arbitrary subtree to be updated, instead
of having to update all the windows. This will be used to make sure
all the children have been updated when the parent window contents need
to be accessed in IncludeInferios sub-window mode.

WindowRec has a new member 'damagedDescendants' that is used to keep
track of which subtrees need updating. When a window is damaged,
'damagedDescendants' will be set for all the ancestors, and when a
subtree is updated, the tree walk can be stopped early if no damaged
descendants are present.

CompScreenRec no longer needs the 'damaged' member since the root
window's 'damagedDescendants' provides the same information.

Signed-off-by: Ville Syrjälä <ville.syrjala at nokia.com>
---
 composite/compalloc.c  |   12 +++++++++---
 composite/compinit.c   |   21 +++++++++++----------
 composite/compint.h    |    1 -
 composite/compwindow.c |    8 ++++++--
 dix/window.c           |    4 ++++
 include/windowstr.h    |    3 +++
 6 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/composite/compalloc.c b/composite/compalloc.c
index 93571ee..df79010 100644
--- a/composite/compalloc.c
+++ b/composite/compalloc.c
@@ -51,12 +51,18 @@ static void
 compReportDamage (DamagePtr pDamage, RegionPtr pRegion, void *closure)
 {
     WindowPtr	    pWin = (WindowPtr) closure;
-    ScreenPtr	    pScreen = pWin->drawable.pScreen;
-    CompScreenPtr   cs = GetCompScreen (pScreen);
     CompWindowPtr   cw = GetCompWindow (pWin);
 
-    cs->damaged = TRUE;
     cw->damaged = TRUE;
+
+    /* Mark the ancestors */
+    pWin = pWin->parent;
+    while (pWin) {
+	if (pWin->damagedDescendants)
+	    break;
+	pWin->damagedDescendants = TRUE;
+	pWin = pWin->parent;
+    }
 }
 
 static void
diff --git a/composite/compinit.c b/composite/compinit.c
index 80b9ddc..f5b134e 100644
--- a/composite/compinit.c
+++ b/composite/compinit.c
@@ -134,15 +134,17 @@ compChangeWindowAttributes(WindowPtr pWin, unsigned long mask)
 }
 
 static void
-compScreenUpdate (ScreenPtr pScreen)
+compChildrenUpdate (WindowPtr pWin)
 {
-    CompScreenPtr   cs = GetCompScreen (pScreen);
+    ScreenPtr pScreen = pWin->drawable.pScreen;
+    WindowPtr pChild;
 
     compCheckTree (pScreen);
-    if (cs->damaged)
-    {
-	compWindowUpdate (pScreen->root);
-	cs->damaged = FALSE;
+
+    if (pWin->damagedDescendants) {
+	for (pChild = pWin->lastChild; pChild; pChild = pChild->prevSib)
+	    compWindowUpdate (pChild);
+	pWin->damagedDescendants = FALSE;
     }
 }
 
@@ -156,7 +158,7 @@ compBlockHandler (int	    i,
     CompScreenPtr   cs = GetCompScreen (pScreen);
 
     pScreen->BlockHandler = cs->BlockHandler;
-    compScreenUpdate (pScreen);
+    compChildrenUpdate (pScreen->root);
     (*pScreen->BlockHandler) (i, blockData, pTimeout, pReadmask);
     cs->BlockHandler = pScreen->BlockHandler;
     pScreen->BlockHandler = compBlockHandler;
@@ -175,7 +177,7 @@ compGetImage (DrawablePtr pDrawable,
 
     pScreen->GetImage = cs->GetImage;
     if (pDrawable->type == DRAWABLE_WINDOW)
-	compScreenUpdate (pScreen);
+	compChildrenUpdate ((WindowPtr) pDrawable);
     (*pScreen->GetImage) (pDrawable, sx, sy, w, h, format, planemask, pdstLine);
     cs->GetImage = pScreen->GetImage;
     pScreen->GetImage = compGetImage;
@@ -191,7 +193,7 @@ static void compSourceValidate(DrawablePtr pDrawable,
 
     pScreen->SourceValidate = cs->SourceValidate;
     if (pDrawable->type == DRAWABLE_WINDOW && subWindowMode == IncludeInferiors)
-	compScreenUpdate (pScreen);
+	compChildrenUpdate ((WindowPtr) pDrawable);
     if (pScreen->SourceValidate)
 	(*pScreen->SourceValidate) (pDrawable, x, y, width, height,
 				    subWindowMode);
@@ -371,7 +373,6 @@ compScreenInit (ScreenPtr pScreen)
     if (!cs)
 	return FALSE;
 
-    cs->damaged = FALSE;
     cs->overlayWid = FakeClientID(0);
     cs->pOverlayWin = NULL;
     cs->pOverlayClients = NULL;
diff --git a/composite/compint.h b/composite/compint.h
index 99d27f6..177965d 100644
--- a/composite/compint.h
+++ b/composite/compint.h
@@ -152,7 +152,6 @@ typedef struct _CompScreen {
 
     ScreenBlockHandlerProcPtr	BlockHandler;
     CloseScreenProcPtr		CloseScreen;
-    Bool			damaged;
     int				numAlternateVisuals;
     VisualID			*alternateVisuals;
 
diff --git a/composite/compwindow.c b/composite/compwindow.c
index 22d2374..df54e96 100644
--- a/composite/compwindow.c
+++ b/composite/compwindow.c
@@ -725,8 +725,12 @@ compWindowUpdate (WindowPtr pWin)
 {
     WindowPtr	pChild;
 
-    for (pChild = pWin->lastChild; pChild; pChild = pChild->prevSib)
-	compWindowUpdate (pChild);
+    if (pWin->damagedDescendants) {
+	for (pChild = pWin->lastChild; pChild; pChild = pChild->prevSib)
+	    compWindowUpdate (pChild);
+	pWin->damagedDescendants = FALSE;
+    }
+
     if (pWin->redirectDraw != RedirectDrawNone)
     {
 	CompWindowPtr	cw = GetCompWindow(pWin);
diff --git a/dix/window.c b/dix/window.c
index d140dda..9be7064 100644
--- a/dix/window.c
+++ b/dix/window.c
@@ -298,6 +298,10 @@ SetWindowToDefaults(WindowPtr pWin)
 #ifdef ROOTLESS
     pWin->rootlessUnhittable = FALSE;
 #endif
+
+#ifdef COMPOSITE
+    pWin->damagedDescendants = FALSE;
+#endif
 }
 
 static void
diff --git a/include/windowstr.h b/include/windowstr.h
index 0b66ebb..4a7a0f4 100644
--- a/include/windowstr.h
+++ b/include/windowstr.h
@@ -167,6 +167,9 @@ typedef struct _Window {
 #ifdef ROOTLESS
     unsigned		rootlessUnhittable:1;	/* doesn't hit-test */
 #endif
+#ifdef COMPOSITE
+    unsigned		damagedDescendants:1;	/* some descendants are damaged */
+#endif
 } WindowRec;
 
 /*
-- 
1.7.2.2