Don't prefetch attribute table sort values when no sorting set

Shaves some seconds off opening the attribute table in certain circumstances (no sorting applied) Drops load time for table from 100 seconds to 50 seconds for a 2.6 million feature shapefile, and from 6.5 seconds to 3.5 seconds for a 160k feature shapefile. Refs #16577, #16239 (cherry-picked from 0b95c77)
qgis · May 23, 2017 · 4acc480 · 4acc480
1 parent 6c126a3
commit 4acc480
Showing 1 changed file with 16 additions and 9 deletions.
diff --git a/src/gui/attributetable/qgsattributetablemodel.cpp b/src/gui/attributetable/qgsattributetablemodel.cpp
@@ -39,7 +39,6 @@ QgsAttributeTableModel::QgsAttributeTableModel( QgsVectorLayerCache *layerCache,
     : QAbstractTableModel( parent )
     , mLayerCache( layerCache )
     , mFieldCount( 0 )
-    , mSortCacheExpression( "" )
     , mSortFieldIndex( -1 )
     , mExtraColumns( 0 )
 {
@@ -207,19 +206,20 @@ void QgsAttributeTableModel::featureAdded( QgsFeatureId fid , bool resettingMode
 
   if ( featOk && mFeatureRequest.acceptFeature( mFeat ) )
   {
-    if ( mSortFieldIndex == -1 )
-    {
-      mExpressionContext.setFeature( mFeat );
-      mSortCache[mFeat.id()] = mSortCacheExpression.evaluate( &mExpressionContext );
-    }
-    else
+
+    if ( mSortFieldIndex >= 0 )
     {
       QgsEditorWidgetFactory* widgetFactory = mWidgetFactories.at( mSortFieldIndex );
       const QVariant& widgetCache = mAttributeWidgetCaches.at( mSortFieldIndex );
       const QgsEditorWidgetConfig& widgetConfig = mWidgetConfigs.at( mSortFieldIndex );
       QVariant sortValue = widgetFactory->representValue( layer(), mSortFieldIndex, widgetConfig, widgetCache, mFeat.attribute( mSortFieldIndex ) );
       mSortCache.insert( mFeat.id(), sortValue );
     }
+    else if ( mSortCacheExpression.isValid() )
+    {
+      mExpressionContext.setFeature( mFeat );
+      mSortCache[mFeat.id()] = mSortCacheExpression.evaluate( &mExpressionContext );
+    }
 
     // Skip if the fid is already in the map (do not add twice)!
     if ( ! mIdRowMap.contains( fid ) )
@@ -780,7 +780,14 @@ void QgsAttributeTableModel::prefetchSortData( const QString& expressionString )
   mSortCache.clear();
   mSortCacheAttributes.clear();
   mSortFieldIndex = -1;
-  mSortCacheExpression = QgsExpression( expressionString );
+  if ( !expressionString.isEmpty() )
+    mSortCacheExpression = QgsExpression( expressionString );
+  else
+  {
+    // no sorting
+    mSortCacheExpression = QgsExpression();
+    return;
+  }
 
   QgsEditorWidgetFactory* widgetFactory = nullptr;
   QVariant widgetCache;
@@ -833,7 +840,7 @@ void QgsAttributeTableModel::prefetchSortData( const QString& expressionString )
 
 QString QgsAttributeTableModel::sortCacheExpression() const
 {
-  if ( mSortCacheExpression.rootNode() )
+  if ( mSortCacheExpression.isValid() )
     return mSortCacheExpression.expression();
   else
     return QString();