Add comment about the callback limitations in QGIS

qgis · Dec 28, 2022 · 98366e1 · 98366e1
1 parent b4d73ca
commit 98366e1
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/src/core/providers/ogr/qgsogrfeatureiterator.cpp b/src/core/providers/ogr/qgsogrfeatureiterator.cpp
@@ -279,6 +279,14 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrFeatureSource *source, bool
 
 #if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(3,7,0)
   // Install query logger
+  // Note: this logger won't track insert/update/delete operations,
+  //       in order to do that the callback would need to be installed
+  //       in the provider's dataset, but because the provider life-cycle
+  //       is significantly longer than this iterator it wouldn't be possible
+  //       to install the callback at a later time if the provider was created
+  //       when the logger was disabled.
+  //       There is currently no API to connect the change of state of the
+  //       logger to the data provider.
   if ( QgsApplication::databaseQueryLog()->enabled() )
   {
     GDALDatasetSetQueryLoggerFunc( mConn->ds, [ ]( const char *pszSQL, const char *pszError, int64_t lNumRecords, int64_t lExecutionTimeMilliseconds, void *pQueryLoggerArg )