Add a bit of typesafety to ogr extent handling

Author: m-kuhn

src/providers/ogr/qgsogrprovider.cpp

@@ -272,7 +272,7 @@ QgsVectorLayerImport::ImportError QgsOgrProvider::createEmptyLayer(
 QgsOgrProvider::QgsOgrProvider( QString const & uri )
     : QgsVectorDataProvider( uri )
     , ogrDataSource( nullptr )
-    , extent_( nullptr )
+    , mExtent( nullptr )
     , ogrLayer( nullptr )
     , ogrOrigLayer( nullptr )
     , mLayerIndex( 0 )
@@ -456,11 +456,7 @@ bool QgsOgrProvider::setSubsetString( const QString& theSQL, bool updateFeatureC
   loadFields();
   QgsDebugMsg( "Done checking validity" );
 
-  if ( extent_ )
-  {
-    free( extent_ );
-    extent_ = nullptr;
-  }
+  updateExtents();
 
   emit dataChanged();
 
@@ -846,26 +842,24 @@ unsigned char * QgsOgrProvider::getGeometryPointer( OGRFeatureH fet )
 
 QgsRectangle QgsOgrProvider::extent()
 {
-  if ( !extent_ )
+  if ( !mExtent )
   {
-    extent_ = calloc( sizeof( OGREnvelope ), 1 );
+    mExtent = new OGREnvelope();
 
     // get the extent_ (envelope) of the layer
     QgsDebugMsg( "Starting get extent" );
 
     // TODO: This can be expensive, do we really need it!
     if ( ogrLayer == ogrOrigLayer )
     {
-      OGR_L_GetExtent( ogrLayer, ( OGREnvelope * ) extent_, true );
+      OGR_L_GetExtent( ogrLayer, mExtent, true );
     }
     else
     {
-      OGREnvelope *bb = static_cast<OGREnvelope*>( extent_ );
-
-      bb->MinX = std::numeric_limits<double>::max();
-      bb->MinY = std::numeric_limits<double>::max();
-      bb->MaxX = -std::numeric_limits<double>::max();
-      bb->MaxY = -std::numeric_limits<double>::max();
+      mExtent->MinX = std::numeric_limits<double>::max();
+      mExtent->MinY = std::numeric_limits<double>::max();
+      mExtent->MaxX = -std::numeric_limits<double>::max();
+      mExtent->MaxY = -std::numeric_limits<double>::max();
 
       OGRFeatureH f;
 
@@ -878,10 +872,10 @@ QgsRectangle QgsOgrProvider::extent()
           OGREnvelope env;
           OGR_G_GetEnvelope( g, &env );
 
-          if ( env.MinX < bb->MinX ) bb->MinX = env.MinX;
-          if ( env.MinY < bb->MinY ) bb->MinY = env.MinY;
-          if ( env.MaxX > bb->MaxX ) bb->MaxX = env.MaxX;
-          if ( env.MaxY > bb->MaxY ) bb->MaxY = env.MaxY;
+          mExtent->MinX = qMin( mExtent->MinX, env.MinX );
+          mExtent->MinY = qMin( mExtent->MinY, env.MinY );
+          mExtent->MaxX = qMin( mExtent->MaxX, env.MaxX );
+          mExtent->MaxY = qMin( mExtent->MaxY, env.MaxY );
         }
 
         OGR_F_Destroy( f );
@@ -892,18 +886,14 @@ QgsRectangle QgsOgrProvider::extent()
     QgsDebugMsg( "Finished get extent" );
   }
 
-  OGREnvelope *ext = static_cast<OGREnvelope *>( extent_ );
-  mExtentRect.set( ext->MinX, ext->MinY, ext->MaxX, ext->MaxY );
+  mExtentRect.set( mExtent->MinX, mExtent->MinY, mExtent->MaxX, mExtent->MaxY );
   return mExtentRect;
 }
 
 void QgsOgrProvider::updateExtents()
 {
-  if ( extent_ )
-  {
-    free( extent_ );
-    extent_ = nullptr;
-  }
+  delete mExtent;
+  mExtent = nullptr;
 }
 
 size_t QgsOgrProvider::layerCount() const
@@ -1409,11 +1399,7 @@ bool QgsOgrProvider::deleteFeatures( const QgsFeatureIds & id )
 
   clearMinMaxCache();
 
-  if ( extent_ )
-  {
-    free( extent_ );
-    extent_ = nullptr;
-  }
+  updateExtents();
 
   return returnvalue;
 }
@@ -2846,11 +2832,7 @@ void QgsOgrProvider::close()
   }
   ogrDataSource = nullptr;
 
-  if ( extent_ )
-  {
-    free( extent_ );
-    extent_ = nullptr;
-  }
+  updateExtents();
 
   QgsOgrConnPool::unrefS( mFilePath );
 }

src/providers/ogr/qgsogrprovider.h

@@ -295,7 +295,7 @@ class QgsOgrProvider : public QgsVectorDataProvider
     OGRwkbGeometryType ogrWkbGeometryTypeFromName( const QString& typeName ) const;
     QgsFields mAttributeFields;
     OGRDataSourceH ogrDataSource;
-    void *extent_;
+    OGREnvelope* mExtent;
 
     /** This member variable receives the same value as extent_
      in the method QgsOgrProvider::extent(). The purpose is to prevent a memory leak*/