cache data_size / calculate more efficiently

src/finam/data/grid_spec.py

@@ -84,6 +84,7 @@ class RectilinearGrid(StructuredGrid):
         self._crs = crs
 
         self._data_shape = None
+        self._data_size = None
 
     def to_unstructured(self):
         """
@@ -116,6 +117,13 @@ class RectilinearGrid(StructuredGrid):
             self._data_shape = super().data_shape
         return self._data_shape
 
+    @property
+    def data_size(self):
+        """int: Size of the associated data."""
+        if self._data_size is None:
+            self._data_size = super().data_size
+        return self._data_size
+
     @property
     def axes(self):
         """list of np.ndarray: Grid points."""
@@ -438,6 +446,15 @@ class UnstructuredGrid(Grid):
             else (len(self.cells),)
         )
 
+    @property
+    def data_size(self):
+        """int: Size of the associated data."""
+        return (
+            len(self.points)
+            if self.data_location == Location.POINTS
+            else len(self.cells)
+        )
+
     @property
     def cells(self):
         """np.ndarray: Cell nodes in ESMF format."""