Use sets for index results

python/core/auto_generated/qgsspatialindexkdbush.sip.in

@@ -65,15 +65,15 @@ Copy constructor
 
     ~QgsSpatialIndexKDBush();
 
-    QList<QgsFeatureId> intersect( const QgsRectangle &rectangle ) const;
+    QSet<QgsFeatureId> intersect( const QgsRectangle &rectangle ) const;
 %Docstring
-Returns a list of features which fall within the specified ``rectangle``.
+Returns the set of features which fall within the specified ``rectangle``.
 %End
 
 
-    QList<QgsFeatureId> within( const QgsPointXY &point, double radius ) const;
+    QSet<QgsFeatureId> within( const QgsPointXY &point, double radius ) const;
 %Docstring
-Returns a list of features which are within the given search ``radius``
+Returns the set of features which are within the given search ``radius``
 of ``point``.
 %End
 
@@ -84,6 +84,11 @@ Fetches the point from the index with matching ``id`` and stores it in ``point``
 
 Returns true if the point was found, or false if no matching feature ID is present
 in the index.
+%End
+
+    qgssize size() const;
+%Docstring
+Returns the size of the index, i.e. the number of points contained within the index.
 %End
 
 };

src/core/qgsspatialindexkdbush.cpp

@@ -56,10 +56,10 @@ QgsSpatialIndexKDBush::~QgsSpatialIndexKDBush()
     delete d;
 }
 
-QList<QgsFeatureId> QgsSpatialIndexKDBush::within( const QgsPointXY &point, double radius ) const
+QSet<QgsFeatureId> QgsSpatialIndexKDBush::within( const QgsPointXY &point, double radius ) const
 {
-  QList<QgsFeatureId> result;
-  d->index->within( point.x(), point.y(), radius, [&result]( const QgsFeatureId id ) { result << id; } );
+  QSet<QgsFeatureId> result;
+  d->index->within( point.x(), point.y(), radius, [&result]( const QgsFeatureId id ) { result.insert( id ); } );
   return result;
 }
 
@@ -73,9 +73,14 @@ bool QgsSpatialIndexKDBush::point( QgsFeatureId id, QgsPointXY &point ) const
   return d->index->point( id, point );
 }
 
-QList<QgsFeatureId> QgsSpatialIndexKDBush::intersect( const QgsRectangle &rectangle ) const
+qgssize QgsSpatialIndexKDBush::size() const
 {
-  QList<QgsFeatureId> result;
+  return d->index->size();
+}
+
+QSet<QgsFeatureId> QgsSpatialIndexKDBush::intersect( const QgsRectangle &rectangle ) const
+{
+  QSet<QgsFeatureId> result;
   d->index->range( rectangle.xMinimum(),
                    rectangle.yMinimum(),
                    rectangle.xMaximum(),

src/core/qgsspatialindexkdbush.h

@@ -83,9 +83,9 @@ class CORE_EXPORT QgsSpatialIndexKDBush
     ~QgsSpatialIndexKDBush();
 
     /**
-     * Returns a list of features which fall within the specified \a rectangle.
+     * Returns the set of features which fall within the specified \a rectangle.
      */
-    QList<QgsFeatureId> intersect( const QgsRectangle &rectangle ) const;
+    QSet<QgsFeatureId> intersect( const QgsRectangle &rectangle ) const;
 
     /**
      * Calls a \a visitor function for all features which fall within the specified \a rectangle.
@@ -95,10 +95,10 @@ class CORE_EXPORT QgsSpatialIndexKDBush
     void intersect( const QgsRectangle &rectangle, const std::function<void( QgsFeatureId )> &visitor ) const SIP_SKIP;
 
     /**
-     * Returns a list of features which are within the given search \a radius
+     * Returns the set of features which are within the given search \a radius
      * of \a point.
      */
-    QList<QgsFeatureId> within( const QgsPointXY &point, double radius ) const;
+    QSet<QgsFeatureId> within( const QgsPointXY &point, double radius ) const;
 
     /**
      * Calls a \a visitor function for all features which are within the given search \a radius
@@ -116,6 +116,11 @@ class CORE_EXPORT QgsSpatialIndexKDBush
      */
     bool point( QgsFeatureId id, QgsPointXY &point ) const;
 
+    /**
+     * Returns the size of the index, i.e. the number of points contained within the index.
+     */
+    qgssize size() const;
+
   private:
 
     //! Implicitly shared data pointer

src/core/qgsspatialindexkdbush_p.h

@@ -99,6 +99,11 @@ class PointXYKDBush : public kdbush::KDBush< std::pair<double, double>, QgsFeatu
       return true;
     }
 
+    std::size_t size() const
+    {
+      return points.size();
+    }
+
   private:
 
     QHash< QgsFeatureId, QgsPointXY > mIdToPoint;

tests/src/core/testqgsspatialindexkdbush.cpp

@@ -73,27 +73,28 @@ class TestQgsSpatialIndexKdBush : public QObject
       for ( QgsFeature f : _pointFeatures() )
         vl->dataProvider()->addFeature( f );
       QgsSpatialIndexKDBush index( *vl->dataProvider() );
+      QCOMPARE( index.size(), 4 );
 
-      QList<QgsFeatureId> fids = index.intersect( QgsRectangle( 0, 0, 10, 10 ) );
+      QSet<QgsFeatureId> fids = index.intersect( QgsRectangle( 0, 0, 10, 10 ) );
       QVERIFY( fids.count() == 1 );
-      QCOMPARE( fids[0], 1 );
+      QVERIFY( fids.contains( 1 ) );
 
-      QList<QgsFeatureId> fids2 = index.intersect( QgsRectangle( -10, -10, 0, 10 ) );
+      QSet<QgsFeatureId> fids2 = index.intersect( QgsRectangle( -10, -10, 0, 10 ) );
       QCOMPARE( fids2.count(), 2 );
       QVERIFY( fids2.contains( 2 ) );
       QVERIFY( fids2.contains( 3 ) );
 
-      QList<QgsFeatureId> fids3 = index.within( QgsPointXY( 0, 0 ), 2 );
+      QSet<QgsFeatureId> fids3 = index.within( QgsPointXY( 0, 0 ), 2 );
       QCOMPARE( fids3.count(), 4 );
       QVERIFY( fids3.contains( 1 ) );
       QVERIFY( fids3.contains( 2 ) );
       QVERIFY( fids3.contains( 3 ) );
       QVERIFY( fids3.contains( 4 ) );
 
-      QList<QgsFeatureId> fids4 = index.within( QgsPointXY( 0, 0 ), 1 );
+      QSet<QgsFeatureId> fids4 = index.within( QgsPointXY( 0, 0 ), 1 );
       QCOMPARE( fids4.count(), 0 );
 
-      QList<QgsFeatureId> fids5 = index.within( QgsPointXY( -1, -1 ), 2.1 );
+      QSet<QgsFeatureId> fids5 = index.within( QgsPointXY( -1, -1 ), 2.1 );
       QCOMPARE( fids5.count(), 3 );
       QVERIFY( fids5.contains( 2 ) );
       QVERIFY( fids5.contains( 3 ) );
@@ -127,9 +128,9 @@ class TestQgsSpatialIndexKdBush : public QObject
       QVERIFY( index->d->ref == 2 );
 
       // test that copied index works
-      QList<QgsFeatureId> fids = indexCopy->intersect( QgsRectangle( 0, 0, 10, 10 ) );
+      QSet<QgsFeatureId> fids = indexCopy->intersect( QgsRectangle( 0, 0, 10, 10 ) );
       QVERIFY( fids.count() == 1 );
-      QCOMPARE( fids[0], 1 );
+      QVERIFY( fids.contains( 1 ) );
 
       // check that the index is still shared
       QCOMPARE( index->d, indexCopy->d );
@@ -140,12 +141,13 @@ class TestQgsSpatialIndexKdBush : public QObject
       // test that copied index still works
       fids = indexCopy->intersect( QgsRectangle( 0, 0, 10, 10 ) );
       QVERIFY( fids.count() == 1 );
-      QCOMPARE( fids[0], 1 );
+      QVERIFY( fids.contains( 1 ) );
       QVERIFY( indexCopy->d->ref == 1 );
 
       // assignment operator
       std::unique_ptr< QgsVectorLayer > vl2 = qgis::make_unique< QgsVectorLayer >( "Point", QString(), QStringLiteral( "memory" ) );
       QgsSpatialIndexKDBush index3( *vl2->dataProvider() );
+      QCOMPARE( index3.size(), 0 );
       fids = index3.intersect( QgsRectangle( 0, 0, 10, 10 ) );
       QCOMPARE( fids.count(), 0 );
       QVERIFY( index3.d->ref == 1 );
@@ -155,7 +157,7 @@ class TestQgsSpatialIndexKdBush : public QObject
       QVERIFY( index3.d->ref == 2 );
       fids = index3.intersect( QgsRectangle( 0, 0, 10, 10 ) );
       QVERIFY( fids.count() == 1 );
-      QCOMPARE( fids[0], 1 );
+      QVERIFY( fids.contains( 1 ) );
 
       indexCopy.reset();
       QVERIFY( index3.d->ref == 1 );