Optimize by reducing invalidation as this can be costly.

If all of the text area or margin area is invalidated then remember this and
don't do any more invalidations for that area until the window is painted.
This reduced the time taken to replace each \r\n with \n\n in very large
files by a factor of 3.

2 files changed, 22 insertions, 0 deletions

diff --git a/src/Editor.cxx b/src/Editor.cxx
index bd2742539..fcd94763c 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -479,11 +479,16 @@ void Editor::DiscardOverdraw() {
 }
 
 void Editor::Redraw() {
+	if (redrawPendingText) {
+		return;
+	}
 	//Platform::DebugPrintf("Redraw all\n");
 	const PRectangle rcClient = GetClientRectangle();
 	wMain.InvalidateRectangle(rcClient);
 	if (wMargin.GetID())
 		wMargin.InvalidateAll();
+	else
+		redrawPendingText = true;
 	//wMain.InvalidateAll();
 }
 
@@ -498,11 +503,15 @@ void Editor::RedrawSelMargin(Sci::Line line, bool allAfter) {
 		Redraw();
 		return;
 	}
+	if (redrawPendingMargin) {
+		return;
+	}
 	PRectangle rcMarkers = GetClientRectangle();
 	if (!markersInText) {
 		// Normal case: just draw the margin
 		rcMarkers.right = rcMarkers.left + vs.fixedColumnWidth;
 	}
+	const PRectangle rcMarkersFull = rcMarkers;
 	if (line != -1) {
 		PRectangle rcLine = RectangleFromRange(Range(pdoc->LineStart(line)), 0);
 
@@ -529,6 +538,9 @@ void Editor::RedrawSelMargin(Sci::Line line, bool allAfter) {
 		wMargin.InvalidateRectangle(rcMarkers);
 	} else {
 		wMain.InvalidateRectangle(rcMarkers);
+		if (rcMarkers == rcMarkersFull) {
+			redrawPendingMargin = true;
+		}
 	}
 }
 
@@ -552,6 +564,9 @@ PRectangle Editor::RectangleFromRange(Range r, int overlap) {
 }
 
 void Editor::InvalidateRange(Sci::Position start, Sci::Position end) {
+	if (redrawPendingText) {
+		return;
+	}
 	RedrawRect(RectangleFromRange(Range(start, end), view.LinesOverlap() ? vs.lineOverlap : 0));
 }
 
@@ -1717,6 +1732,9 @@ void Editor::RefreshPixMaps(Surface *surfaceWindow) {
 }
 
 void Editor::Paint(Surface *surfaceWindow, PRectangle rcArea) {
+	redrawPendingText = false;
+	redrawPendingMargin = false;
+
 	//Platform::DebugPrintf("Paint:%1d (%3d,%3d) ... (%3d,%3d)\n",
 	//	paintingAllText, rcArea.left, rcArea.top, rcArea.right, rcArea.bottom);
 
diff --git a/src/Editor.h b/src/Editor.h
index 417700ed5..37df93c93 100644
--- a/src/Editor.h
+++ b/src/Editor.h
@@ -188,6 +188,10 @@ protected:	// ScintillaBase subclass needs access to much of Editor
 	Window wMain;	///< The Scintilla parent window
 	Window wMargin;	///< May be separate when using a scroll view for wMain
 
+	// Optimization that avoids superfluous invalidations
+	bool redrawPendingText = false;
+	bool redrawPendingMargin = false;
+
 	/** Style resources may be expensive to allocate so are cached between uses.
 	 * When a style attribute is changed, this cache is flushed. */
 	bool stylesValid;