Implement scoped pointers for gdal handled objects

src/app/dwg/qgsdwgimporter.h

@@ -21,6 +21,7 @@
 #include <ogr_api.h>
 
 #include "qgsabstractgeometry.h"
+#include "qgsogrutils.h"
 
 class QgsCompoundCurve;
 class QgsQgsCoordinateReferenceSystem;
@@ -186,7 +187,7 @@ class QgsDwgImporter : public DRW_Interface
 
     bool createFeature( OGRLayerH layer, OGRFeatureH f, const QgsAbstractGeometry &g ) const;
 
-    OGRDataSourceH mDs;
+    gdal::ogr_datasource_unique_ptr mDs;
     QString mDatabase;
     bool mInTransaction;
     int mSplineSegs;

src/core/qgsgml.cpp

@@ -21,7 +21,7 @@
 #include "qgsmessagelog.h"
 #include "qgsnetworkaccessmanager.h"
 #include "qgswkbptr.h"
-
+#include "qgsogrutils.h"
 #include <QBuffer>
 #include <QList>
 #include <QNetworkRequest>
@@ -875,20 +875,19 @@ void QgsGmlStreamingParser::endElement( const XML_Char *el )
     mParseModeStack.pop();
     if ( mFoundUnhandledGeometryElement )
     {
-      OGRGeometryH hGeom = OGR_G_CreateFromGML( mGeometryString.c_str() );
+      gdal::ogr_geometry_unique_ptr hGeom( OGR_G_CreateFromGML( mGeometryString.c_str() ) );
       if ( hGeom )
       {
-        const int wkbSize = OGR_G_WkbSize( hGeom );
+        const int wkbSize = OGR_G_WkbSize( hGeom.get() );
         unsigned char *pabyBuffer = new unsigned char[ wkbSize ];
-        OGR_G_ExportToIsoWkb( hGeom, wkbNDR, pabyBuffer );
+        OGR_G_ExportToIsoWkb( hGeom.get(), wkbNDR, pabyBuffer );
         QgsGeometry g;
         g.fromWkb( pabyBuffer, wkbSize );
         if ( mInvertAxisOrientation )
         {
           g.transform( QTransform( 0, 1, 1, 0, 0, 0 ) );
         }
         mCurrentFeature->setGeometry( g );
-        OGR_G_DestroyGeometry( hGeom );
       }
     }
     mGeometryString.clear();

src/core/qgsogrutils.cpp

@@ -28,6 +28,29 @@
 #define OGR_F_IsFieldSetAndNotNull OGR_F_IsFieldSet
 #endif
 
+
+
+void gdal::OGRDataSourceDeleter::operator()( void *source )
+{
+  OGR_DS_Destroy( source );
+}
+
+
+void gdal::OGRGeometryDeleter::operator()( void *geometry )
+{
+  OGR_G_DestroyGeometry( geometry );
+}
+
+void gdal::OGRFldDeleter::operator()( void *definition )
+{
+  OGR_Fld_Destroy( definition );
+}
+
+void gdal::OGRFeatureDeleter::operator()( void *feature )
+{
+  OGR_F_Destroy( feature );
+}
+
 QgsFeature QgsOgrUtils::readOgrFeature( OGRFeatureH ogrFet, const QgsFields &fields, QTextCodec *encoding )
 {
   QgsFeature feature;
@@ -297,32 +320,30 @@ QgsFeatureList QgsOgrUtils::stringToFeatureList( const QString &string, const Qg
   VSIFCloseL( VSIFileFromMemBuffer( randomFileName.toUtf8().constData(), reinterpret_cast< GByte * >( ba.data() ),
                                     static_cast< vsi_l_offset >( ba.size() ), FALSE ) );
 
-  OGRDataSourceH hDS = OGROpen( randomFileName.toUtf8().constData(), false, nullptr );
+  gdal::ogr_datasource_unique_ptr hDS( OGROpen( randomFileName.toUtf8().constData(), false, nullptr ) );
   if ( !hDS )
   {
     VSIUnlink( randomFileName.toUtf8().constData() );
     return features;
   }
 
-  OGRLayerH ogrLayer = OGR_DS_GetLayer( hDS, 0 );
+  OGRLayerH ogrLayer = OGR_DS_GetLayer( hDS.get(), 0 );
   if ( !ogrLayer )
   {
-    OGR_DS_Destroy( hDS );
+    hDS.reset();
     VSIUnlink( randomFileName.toUtf8().constData() );
     return features;
   }
 
-  OGRFeatureH oFeat;
-  while ( ( oFeat = OGR_L_GetNextFeature( ogrLayer ) ) )
+  gdal::ogr_feature_unique_ptr oFeat;
+  while ( oFeat.reset( OGR_L_GetNextFeature( ogrLayer ) ), oFeat )
   {
-    QgsFeature feat = readOgrFeature( oFeat, fields, encoding );
+    QgsFeature feat = readOgrFeature( oFeat.get(), fields, encoding );
     if ( feat.isValid() )
       features << feat;
-
-    OGR_F_Destroy( oFeat );
   }
 
-  OGR_DS_Destroy( hDS );
+  hDS.reset();
   VSIUnlink( randomFileName.toUtf8().constData() );
 
   return features;
@@ -341,30 +362,30 @@ QgsFields QgsOgrUtils::stringToFields( const QString &string, QTextCodec *encodi
   VSIFCloseL( VSIFileFromMemBuffer( randomFileName.toUtf8().constData(), reinterpret_cast< GByte * >( ba.data() ),
                                     static_cast< vsi_l_offset >( ba.size() ), FALSE ) );
 
-  OGRDataSourceH hDS = OGROpen( randomFileName.toUtf8().constData(), false, nullptr );
+  gdal::ogr_datasource_unique_ptr hDS( OGROpen( randomFileName.toUtf8().constData(), false, nullptr ) );
   if ( !hDS )
   {
     VSIUnlink( randomFileName.toUtf8().constData() );
     return fields;
   }
 
-  OGRLayerH ogrLayer = OGR_DS_GetLayer( hDS, 0 );
+  OGRLayerH ogrLayer = OGR_DS_GetLayer( hDS.get(), 0 );
   if ( !ogrLayer )
   {
-    OGR_DS_Destroy( hDS );
+    hDS.reset();
     VSIUnlink( randomFileName.toUtf8().constData() );
     return fields;
   }
 
-  OGRFeatureH oFeat;
+  gdal::ogr_feature_unique_ptr oFeat;
   //read in the first feature only
-  if ( ( oFeat = OGR_L_GetNextFeature( ogrLayer ) ) )
+  if ( oFeat.reset( OGR_L_GetNextFeature( ogrLayer ) ), oFeat )
   {
-    fields = readOgrFields( oFeat, encoding );
-    OGR_F_Destroy( oFeat );
+    fields = readOgrFields( oFeat.get(), encoding );
   }
 
-  OGR_DS_Destroy( hDS );
+  hDS.reset();
   VSIUnlink( randomFileName.toUtf8().constData() );
   return fields;
 }
+

src/core/qgsogrutils.h

@@ -25,6 +25,82 @@
 #include "cpl_conv.h"
 #include "cpl_string.h"
 
+namespace gdal
+{
+
+  /**
+   * Destroys OGR data sources.
+   */
+  struct OGRDataSourceDeleter
+  {
+
+    /**
+     * Destroys an OGR data \a source, using the correct gdal calls.
+     */
+    void CORE_EXPORT operator()( void *source );
+
+  };
+
+  /**
+   * Destroys OGR geometries.
+   */
+  struct OGRGeometryDeleter
+  {
+
+    /**
+     * Destroys an OGR \a geometry, using the correct gdal calls.
+     */
+    void CORE_EXPORT operator()( void *geometry );
+
+  };
+
+  /**
+   * Destroys OGR field definition.
+   */
+  struct OGRFldDeleter
+  {
+
+    /**
+     * Destroys an OGR field \a definition, using the correct gdal calls.
+     */
+    void CORE_EXPORT operator()( void *definition );
+
+  };
+
+  /**
+   * Destroys OGR feature.
+   */
+  struct OGRFeatureDeleter
+  {
+
+    /**
+     * Destroys an OGR \a feature, using the correct gdal calls.
+     */
+    void CORE_EXPORT operator()( void *feature );
+
+  };
+
+  /**
+   * Scoped OGR data source.
+   */
+  using ogr_datasource_unique_ptr = std::unique_ptr< void, OGRDataSourceDeleter>;
+
+  /**
+   * Scoped OGR geometry.
+   */
+  using ogr_geometry_unique_ptr = std::unique_ptr< void, OGRGeometryDeleter>;
+
+  /**
+   * Scoped OGR field definition.
+   */
+  using ogr_field_def_unique_ptr = std::unique_ptr< void, OGRFldDeleter >;
+
+  /**
+   * Scoped OGR feature.
+   */
+  using ogr_feature_unique_ptr = std::unique_ptr< void, OGRFeatureDeleter >;
+}
+
 /**
  * \ingroup core
  * \class QgsOgrUtils