Use QVector::reserve() all over the place.

Reduces internal memory fragmentation.

The search criteria was:
QVector::append(), QVector::push_back(), QVector::operator<<()
and QVector::operator+=() calls inside for, do and while loops.
Statements inside ifs and out of loops weren't considered.

Change-Id: Ie5aaf3cdfac938994e6e5dfa5f51de501ed79a0c
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

2 files changed, 6 insertions, 2 deletions

diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp
index 62492980de..c1737e7746 100644
--- a/src/gui/painting/qplatformbackingstore.cpp
+++ b/src/gui/painting/qplatformbackingstore.cpp
@@ -220,7 +220,9 @@ static QRegion deviceRegion(const QRegion &region, QWindow *window)
         return region;
 
     QVector<QRect> rects;
-    foreach (QRect rect, region.rects())
+    const QVector<QRect> regionRects = region.rects();
+    rects.reserve(regionRects.count());
+    foreach (const QRect &rect, regionRects)
         rects.append(deviceRect(rect, window));
 
     QRegion deviceRegion;
diff --git a/src/gui/painting/qtransform.cpp b/src/gui/painting/qtransform.cpp
index fca2b72249..a23aabe559 100644
--- a/src/gui/painting/qtransform.cpp
+++ b/src/gui/painting/qtransform.cpp
@@ -1381,7 +1381,9 @@ static QPolygonF mapProjective(const QTransform &transform, const QPolygonF &pol
     path = transform.map(path);
 
     QPolygonF result;
-    for (int i = 0; i < path.elementCount(); ++i)
+    const int elementCount = path.elementCount();
+    result.reserve(elementCount);
+    for (int i = 0; i < elementCount; ++i)
         result << path.elementAt(i);
     return result;
 }