Micro optimization: very slightly cheaper QgsFeature::initAttributes …

…call
qgis · Sep 28, 2018 · 94b1082 · 94b1082
1 parent 8ae35de
commit 94b1082
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/core/qgsfeature.cpp b/src/core/qgsfeature.cpp
@@ -195,10 +195,10 @@ bool QgsFeature::hasGeometry() const
 void QgsFeature::initAttributes( int fieldCount )
 {
   d.detach();
+  d->attributes.resize( 0 ); // clears existing elements, while still preserving the currently allocated capacity of the list (unlike clear)
+  // ensures ALL attributes, including previously existing ones are default constructed.
+  // doing it this way also avoids clearing individual QVariants -- which can trigger a detachment. Cheaper just to make a new one.
   d->attributes.resize( fieldCount );
-  QVariant *ptr = d->attributes.data();
-  for ( int i = 0; i < fieldCount; ++i, ++ptr )
-    ptr->clear();
 }
 
 bool QgsFeature::setAttribute( int idx, const QVariant &value )