OGR data provider: use transactions when changing attributes and geometries (if possible) (fixes #16216)

Author: landam

src/providers/ogr/qgsogrprovider.cpp

@@ -1520,6 +1520,31 @@ bool QgsOgrProvider::renameAttributes( const QgsFieldNameMap &renamedAttributes
   return result;
 }
 
+bool QgsOgrProvider::startTransaction()
+{
+  bool inTransaction = false;
+  if ( OGR_L_TestCapability( ogrLayer, OLCTransactions ) )
+  {
+    // A transaction might already be active, so be robust on failed
+    // StartTransaction.
+    CPLPushErrorHandler( CPLQuietErrorHandler );
+    inTransaction = ( OGR_L_StartTransaction( ogrLayer ) == OGRERR_NONE );
+    CPLPopErrorHandler();
+  }
+  return inTransaction;
+}
+
+
+bool QgsOgrProvider::commitTransaction()
+{
+  if ( OGR_L_CommitTransaction( ogrLayer ) != OGRERR_NONE )
+  {
+    pushError( tr( "OGR error committing transaction: %1" ).arg( CPLGetLastErrorMsg() ) );
+    return false;
+  }
+  return true;
+}
+
 
 bool QgsOgrProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_map )
 {
@@ -1533,6 +1558,8 @@ bool QgsOgrProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
 
   setRelevantFields( ogrLayer, true, attributeIndexes() );
 
+  const bool inTransaction = startTransaction();
+
   for ( QgsChangedAttributesMap::const_iterator it = attr_map.begin(); it != attr_map.end(); ++it )
   {
     QgsFeatureId fid = it.key();
@@ -1646,6 +1673,11 @@ bool QgsOgrProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
     OGR_F_Destroy( of );
   }
 
+  if ( inTransaction )
+  {
+    commitTransaction();
+  }
+
   if ( OGR_L_SyncToDisk( ogrLayer ) != OGRERR_NONE )
   {
     pushError( tr( "OGR error syncing to disk: %1" ).arg( CPLGetLastErrorMsg() ) );
@@ -1661,6 +1693,8 @@ bool QgsOgrProvider::changeGeometryValues( const QgsGeometryMap &geometry_map )
 
   setRelevantFields( ogrLayer, true, attributeIndexes() );
 
+  const bool inTransaction = startTransaction();
+
   for ( QgsGeometryMap::const_iterator it = geometry_map.constBegin(); it != geometry_map.constEnd(); ++it )
   {
     if ( FID_TO_NUMBER( it.key() ) > std::numeric_limits<long>::max() )
@@ -1729,6 +1763,12 @@ bool QgsOgrProvider::changeGeometryValues( const QgsGeometryMap &geometry_map )
 
     OGR_F_Destroy( theOGRFeature );
   }
+
+  if ( inTransaction )
+  {
+    commitTransaction();
+  }
+
   QgsOgrConnPool::instance()->invalidateConnections( dataSourceUri() );
   return syncToDisc();
 }

src/providers/ogr/qgsogrprovider.h

@@ -167,6 +167,12 @@ class QgsOgrProvider : public QgsVectorDataProvider
     unsigned char *getGeometryPointer( OGRFeatureH fet );
     QString ogrWkbGeometryTypeName( OGRwkbGeometryType type ) const;
 
+    //! Starts a transaction if possible and return true in that case
+    bool startTransaction();
+
+    //! Commits a transaction
+    bool commitTransaction();
+
     QgsFields mAttributeFields;
 
     //! Map of field index to default value