[api] Add compare methods to QgsFeatureRequest

This will allow to reduce unnecessary expensive calls
when the request has not really changed.

python/PyQt6/core/auto_generated/qgsfeaturerequest.sip.in

@@ -204,6 +204,10 @@ Create a new empty order by
 Create a new order by from a list of clauses
 %End
 
+        bool operator==( const OrderBy &v ) const;
+
+        bool operator!=( const OrderBy &v ) const;
+
         QList<QgsFeatureRequest::OrderByClause> list() const;
 %Docstring
 Gets a copy as a list of OrderByClauses
@@ -275,6 +279,17 @@ construct a request with a filter expression
     QgsFeatureRequest( const QgsFeatureRequest &rh );
 %Docstring
 copy constructor
+%End
+
+    bool compare( const QgsFeatureRequest &other ) const;
+%Docstring
+Compare two requests for equality, ignoring Expression Context, Transform Error Callback, Feedback and Invalid Geometry Callback
+
+:param other: the other request
+
+:return: true if the requests are equal in all respects but without checking for Expression Context, Transform Error, Feedback and Invalid Geometry Callback
+
+.. versionadded:: 3.38
 %End
 
     ~QgsFeatureRequest();

python/core/auto_generated/qgsfeaturerequest.sip.in

@@ -204,6 +204,10 @@ Create a new empty order by
 Create a new order by from a list of clauses
 %End
 
+        bool operator==( const OrderBy &v ) const;
+
+        bool operator!=( const OrderBy &v ) const;
+
         QList<QgsFeatureRequest::OrderByClause> list() const;
 %Docstring
 Gets a copy as a list of OrderByClauses
@@ -275,6 +279,17 @@ construct a request with a filter expression
     QgsFeatureRequest( const QgsFeatureRequest &rh );
 %Docstring
 copy constructor
+%End
+
+    bool compare( const QgsFeatureRequest &other ) const;
+%Docstring
+Compare two requests for equality, ignoring Expression Context, Transform Error Callback, Feedback and Invalid Geometry Callback
+
+:param other: the other request
+
+:return: true if the requests are equal in all respects but without checking for Expression Context, Transform Error, Feedback and Invalid Geometry Callback
+
+.. versionadded:: 3.38
 %End
 
     ~QgsFeatureRequest();

src/core/qgsfeaturerequest.cpp

@@ -98,6 +98,34 @@ QgsFeatureRequest &QgsFeatureRequest::operator=( const QgsFeatureRequest &rh )
   return *this;
 }
 
+// Relaxed Equality operator
+bool QgsFeatureRequest::compare( const QgsFeatureRequest &rh ) const
+{
+  if ( &rh == this )
+    return true;
+
+  return mFlags == rh.mFlags &&
+         mFilter == rh.mFilter &&
+         mSpatialFilter == rh.mSpatialFilter &&
+         mFilterRect == rh.mFilterRect &&
+         ( ( mReferenceGeometry.isNull() && rh.mReferenceGeometry.isNull() ) || mReferenceGeometry.equals( rh.mReferenceGeometry ) ) &&
+         mDistanceWithin == rh.mDistanceWithin &&
+         mFilterFid == rh.mFilterFid &&
+         mFilterFids == rh.mFilterFids &&
+         ( mFilterExpression ? rh.mFilterExpression && *mFilterExpression == *rh.mFilterExpression : !rh.mFilterExpression ) &&
+         mInvalidGeometryFilter == rh.mInvalidGeometryFilter &&
+         mAttrs == rh.mAttrs &&
+         mSimplifyMethod == rh.mSimplifyMethod &&
+         mLimit == rh.mLimit &&
+         mOrderBy == rh.mOrderBy &&
+         mCrs == rh.mCrs &&
+         mTransformContext == rh.mTransformContext &&
+         mTimeout == rh.mTimeout &&
+         mRequestMayBeNested == rh.mRequestMayBeNested;
+
+}
+
+
 QgsFeatureRequest &QgsFeatureRequest::setFilterRect( const QgsRectangle &rect )
 {
   mFilterRect = rect;
@@ -515,6 +543,25 @@ QgsFeatureRequest::OrderBy::OrderBy( const QList<QgsFeatureRequest::OrderByClaus
   }
 }
 
+bool QgsFeatureRequest::OrderBy::operator== ( const QgsFeatureRequest::OrderBy &other ) const
+{
+  if ( this == &other )
+    return true;
+  if ( size() != other.size() )
+    return false;
+  for ( int i = 0; i < size(); ++i )
+  {
+    if ( at( i ) != other.at( i ) )
+      return false;
+  }
+  return true;
+}
+
+bool QgsFeatureRequest::OrderBy::operator!= ( const QgsFeatureRequest::OrderBy &other ) const
+{
+  return !operator==( other );
+}
+
 QList<QgsFeatureRequest::OrderByClause> QgsFeatureRequest::OrderBy::list() const
 {
   return *this;

src/core/qgsfeaturerequest.h

@@ -230,6 +230,18 @@ class CORE_EXPORT QgsFeatureRequest
          */
         CORE_EXPORT OrderBy( const QList<QgsFeatureRequest::OrderByClause> &other );
 
+        /**
+         * Equality operator
+         * \since QGIS 3.8
+         */
+        CORE_EXPORT bool operator==( const OrderBy &v ) const;
+
+        /**
+         * Inequality operator
+         * \since QGIS 3.8
+         */
+        CORE_EXPORT bool operator!=( const OrderBy &v ) const;
+
         /**
          * Gets a copy as a list of OrderByClauses
          *
@@ -294,6 +306,14 @@ class CORE_EXPORT QgsFeatureRequest
     //! Assignment operator
     QgsFeatureRequest &operator=( const QgsFeatureRequest &rh );
 
+    /**
+     * Compare two requests for equality, ignoring Expression Context, Transform Error Callback, Feedback and Invalid Geometry Callback
+     * \param other the other request
+     * \return true if the requests are equal in all respects but without checking for Expression Context, Transform Error, Feedback and Invalid Geometry Callback
+     * \since QGIS 3.38
+     */
+    bool compare( const QgsFeatureRequest &other ) const;
+
     ~QgsFeatureRequest();
 
     /**

tests/src/python/test_qgsfeaturerequest.py

@@ -410,6 +410,86 @@ class TestQgsFeatureRequest(QgisTestCase):
         self.assertEqual(req2.distanceWithin(), 1.2)
         self.assertEqual(req2.filterRect(), QgsRectangle(-1.2, -1.2, 12.2, 3.2))
 
+    def test_compare(self):
+
+        req1 = QgsFeatureRequest().setFilterFids([8, 9]).setFilterRect(QgsRectangle(1, 2, 3, 4)).setInvalidGeometryCheck(QgsFeatureRequest.InvalidGeometryCheck.GeometrySkipInvalid).setLimit(6).setFlags(QgsFeatureRequest.Flag.ExactIntersect).setSubsetOfAttributes([1, 4]).setTimeout(6).setRequestMayBeNested(True)
+        req2 = QgsFeatureRequest(req1)
+        self.assertTrue(req1.compare(req1))
+        self.assertTrue(req1.compare(req2))
+
+        req3 = QgsFeatureRequest(req2)
+        self.assertTrue(req3.compare(req2))
+        self.assertTrue(req3.compare(req1))
+        req3.setFilterFids([8, 9, 10])
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setFilterRect(QgsRectangle(1, 2, 3, 5))
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setInvalidGeometryCheck(QgsFeatureRequest.InvalidGeometryCheck.GeometryNoCheck)
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setLimit(7)
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setFlags(QgsFeatureRequest.Flag.NoGeometry)
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setSubsetOfAttributes([1, 4, 5])
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setTimeout(7)
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        req3.setRequestMayBeNested(False)
+        self.assertFalse(req3.compare(req1))
+
+        req3 = QgsFeatureRequest(req2)
+        orderClause = QgsFeatureRequest.OrderByClause('a', False)
+        order = QgsFeatureRequest.OrderBy([orderClause])
+        req3.setOrderBy(order)
+        self.assertFalse(req3.compare(req1))
+        req4 = QgsFeatureRequest(req2)
+        orderClause = QgsFeatureRequest.OrderByClause('a', False)
+        order2 = QgsFeatureRequest.OrderBy([orderClause])
+        req4.setOrderBy(order2)
+        self.assertTrue(req4.compare(req3))
+        self.assertTrue(order == order2)
+
+        # Expression Context is not checked
+        req3 = QgsFeatureRequest(req2)
+        context = QgsExpressionContext()
+        scope = QgsExpressionContextScope()
+        scope.setVariable('a', 6)
+        context.appendScope(scope)
+        req3.setExpressionContext(context)
+        self.assertTrue(req3.compare(req1))
+
+    def test_order_by_equality(self):
+
+        orderClause1 = QgsFeatureRequest.OrderByClause('a', False)
+        orderClause2 = QgsFeatureRequest.OrderByClause('a', False)
+        self.assertTrue(orderClause1 == orderClause2)
+        orderClause2 = QgsFeatureRequest.OrderByClause('b', False)
+        self.assertFalse(orderClause1 == orderClause2)
+        orderClause2 = QgsFeatureRequest.OrderByClause('a', True)
+        self.assertFalse(orderClause1 == orderClause2)
+
+        order1 = QgsFeatureRequest.OrderBy([orderClause1])
+        order2 = QgsFeatureRequest.OrderBy([orderClause1])
+        self.assertTrue(order1 == order2)
+        order2 = QgsFeatureRequest.OrderBy([orderClause2])
+        self.assertFalse(order1 == order2)
+        order2 = QgsFeatureRequest.OrderBy([orderClause1, orderClause2])
+        self.assertFalse(order1 == order2)
+
 
 if __name__ == '__main__':
     unittest.main()