Use a new ogr layer per iterator

Author: NathanW2

src/providers/ogr/qgsogrfeatureiterator.cpp

@@ -32,15 +32,19 @@
 
 
 QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrProvider* p, const QgsFeatureRequest& request )
-    : QgsAbstractFeatureIterator( request ), P( p )
+  : QgsAbstractFeatureIterator( request ), P( p ), ogrDataSource(0), ogrLayer(0), ogrDriver(0)
 {
-  // make sure that only one iterator is active
-  if ( P->mActiveIterator )
+
+  ogrDataSource = OGROpen( TO8F( P->filePath() ), false, &ogrDriver );
+
+  if ( P->layerName().isNull() )
+  {
+    ogrLayer = OGR_DS_GetLayer( ogrDataSource, P->layerIndex() );
+  }
+  else
   {
-    QgsMessageLog::logMessage( QObject::tr( "Already active iterator on this provider was closed." ), QObject::tr( "OGR" ) );
-    P->mActiveIterator->close();
+    ogrLayer = OGR_DS_GetLayerByName( ogrDataSource, TO8( p->layerName() ) );
   }
-  P->mActiveIterator = this;
 
   mFeatureFetched = false;
 
@@ -56,12 +60,12 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrProvider* p, const QgsFeatur
 
     OGR_G_CreateFromWkt(( char ** )&wktText, NULL, &filter );
     QgsDebugMsg( "Setting spatial filter using " + wktExtent );
-    OGR_L_SetSpatialFilter( P->ogrLayer, filter );
+    OGR_L_SetSpatialFilter( ogrLayer, filter );
     OGR_G_DestroyGeometry( filter );
   }
   else
   {
-    OGR_L_SetSpatialFilter( P->ogrLayer, 0 );
+    OGR_L_SetSpatialFilter( ogrLayer, 0 );
   }
 
   //start with first feature
@@ -94,7 +98,7 @@ bool QgsOgrFeatureIterator::nextFeature( QgsFeature& feature )
 
   if ( mRequest.filterType() == QgsFeatureRequest::FilterFid )
   {
-    OGRFeatureH fet = OGR_L_GetFeature( P->ogrLayer, FID_TO_NUMBER( mRequest.filterFid() ) );
+    OGRFeatureH fet = OGR_L_GetFeature( ogrLayer, FID_TO_NUMBER( mRequest.filterFid() ) );
     if ( !fet )
     {
       close();
@@ -111,7 +115,7 @@ bool QgsOgrFeatureIterator::nextFeature( QgsFeature& feature )
 
   OGRFeatureH fet;
 
-  while (( fet = OGR_L_GetNextFeature( P->ogrLayer ) ) )
+  while (( fet = OGR_L_GetNextFeature( ogrLayer ) ) )
   {
     if ( !readFeature( fet, feature ) )
       continue;
@@ -135,7 +139,7 @@ bool QgsOgrFeatureIterator::rewind()
   if ( mClosed )
     return false;
 
-  OGR_L_ResetReading( P->ogrLayer );
+  OGR_L_ResetReading( ogrLayer );
 
   return true;
 }
@@ -146,10 +150,11 @@ bool QgsOgrFeatureIterator::close()
   if ( mClosed )
     return false;
 
-  // tell provider that this iterator is not active anymore
-  P->mActiveIterator = 0;
+  OGR_DS_ReleaseResultSet( ogrDataSource, ogrLayer );
+  OGR_DS_Destroy( ogrDataSource );
 
   mClosed = true;
+  ogrDataSource = 0;
   return true;
 }
 

src/providers/ogr/qgsogrfeatureiterator.h

@@ -48,6 +48,10 @@ class QgsOgrFeatureIterator : public QgsAbstractFeatureIterator
     void getFeatureAttribute( OGRFeatureH ogrFet, QgsFeature & f, int attindex );
 
     bool mFeatureFetched;
+
+    OGRDataSourceH ogrDataSource;
+    OGRLayerH ogrLayer;
+    OGRSFDriverH ogrDriver;
 };
 
 

src/providers/ogr/qgsogrprovider.cpp

@@ -360,8 +360,7 @@ QgsOgrProvider::QgsOgrProvider( QString const & uri )
 
 QgsOgrProvider::~QgsOgrProvider()
 {
-  if ( mActiveIterator )
-    mActiveIterator->close();
+  // Do we need to close all active iterators here?
 
   if ( ogrLayer != ogrOrigLayer )
   {

src/providers/ogr/qgsogrprovider.h

@@ -250,6 +250,12 @@ class QgsOgrProvider : public QgsVectorDataProvider
     /** Get single flatten geometry type */
     static OGRwkbGeometryType ogrWkbSingleFlatten( OGRwkbGeometryType type );
 
+    QString layerName() { return mLayerName; }
+
+    QString filePath() { return mFilePath; }
+
+    int layerIndex() { return mLayerIndex; }
+
   protected:
     /** loads fields from input file to member attributeFields */
     void loadFields();