Add custom hash for QgsFeature

Fixes #49932 (cherry picked from commit fc0e97e)
qgis · Sep 16, 2022 · 6e50b6d · 6e50b6d
1 parent c547b6a
commit 6e50b6d
Show file tree

Hide file tree

Showing 3 changed files with 37 additions and 1 deletion.
diff --git a/python/core/auto_generated/qgsfeature.sip.in b/python/core/auto_generated/qgsfeature.sip.in
@@ -135,6 +135,11 @@ geometry and a list of field/values attributes.
       sipCpp->deleteAttribute( fieldIdx );
 %End
 
+    long __hash__() const;
+%MethodCode
+    sipRes = qHash( *sipCpp );
+%End
+
     QgsFeature( qint64 id = FID_NULL );
 %Docstring
 Constructor for QgsFeature

diff --git a/src/core/qgsfeature.h b/src/core/qgsfeature.h
@@ -169,6 +169,11 @@ class CORE_EXPORT QgsFeature
     else
       sipCpp->deleteAttribute( fieldIdx );
     % End
+
+    long __hash__() const;
+    % MethodCode
+    sipRes = qHash( *sipCpp );
+    % End
 #endif
 
     /**
@@ -881,7 +886,7 @@ typedef QMap<qint64, QgsGeometry> QgsGeometryMap;
 
 typedef QList<QgsFeature> QgsFeatureList;
 
-uint qHash( const QgsFeature &key, uint seed = 0 )  SIP_SKIP;
+CORE_EXPORT uint qHash( const QgsFeature &key, uint seed = 0 )  SIP_SKIP;
 
 Q_DECLARE_METATYPE( QgsFeature )
 Q_DECLARE_METATYPE( QgsFeatureList )

diff --git a/tests/src/python/test_qgsfeature.py b/tests/src/python/test_qgsfeature.py
@@ -98,6 +98,32 @@ def test_equality(self):
         feat2.setFields(fields)
         self.assertNotEqual(feat, feat2)
 
+    def test_hash(self):
+        fields = QgsFields()
+        field1 = QgsField('my_field')
+        fields.append(field1)
+        field2 = QgsField('my_field2')
+        fields.append(field2)
+
+        feat = QgsFeature(fields, 0)
+        feat.initAttributes(1)
+        feat.setAttribute(0, "text")
+        feat.setGeometry(QgsGeometry.fromPointXY(QgsPointXY(123, 456)))
+
+        self.assertIsNotNone(hash(feat))
+
+        # try a second identical feature, hash should be the same
+        feat2 = QgsFeature(fields, 0)
+        feat2.initAttributes(1)
+        feat2.setAttribute(0, "text")
+        feat2.setGeometry(QgsGeometry.fromPointXY(QgsPointXY(123, 456)))
+
+        self.assertEqual(hash(feat), hash(feat2))
+
+        # different feature, different hash
+        feat2.setId(100)
+        self.assertNotEqual(hash(feat), hash(feat2))
+
     def test_ValidFeature(self):
         myPath = os.path.join(unitTestDataPath(), 'points.shp')
         myLayer = QgsVectorLayer(myPath, 'Points', 'ogr')