From 3489274daf187993c939aeba02fab4028383a055 Mon Sep 17 00:00:00 2001
From: Maximilian Bergbauer <maximilian.bergbauer@tum.de>
Date: Wed, 7 Jun 2023 11:25:27 +0200
Subject: [PATCH] Reuse MappingInfo

---
 include/deal.II/non_matching/mapping_info.h | 23 +++++++++++++++++++++
 tests/non_matching/mapping_info_03.cc       | 18 +++++-----------
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/include/deal.II/non_matching/mapping_info.h b/include/deal.II/non_matching/mapping_info.h
index 85c7c512bd..aed1d2a12d 100644
--- a/include/deal.II/non_matching/mapping_info.h
+++ b/include/deal.II/non_matching/mapping_info.h
@@ -434,6 +434,12 @@ namespace NonMatching
     unsigned int
     compute_n_q_points(const unsigned int n_q_points_unvectorized);
 
+    /**
+     * Clears fields to make the object reusable.
+     */
+    void
+    clear();
+
     /**
      * Resize the unit_point data field.
      */
@@ -673,6 +679,17 @@ namespace NonMatching
 
 
 
+  template <int dim, int spacedim, typename Number>
+  void
+  MappingInfo<dim, spacedim, Number>::clear()
+  {
+    n_q_points_unvectorized.clear();
+    unit_points_index.clear();
+    data_index_offsets.clear();
+  }
+
+
+
   template <int dim, int spacedim, typename Number>
   void
   MappingInfo<dim, spacedim, Number>::reinit(
@@ -778,6 +795,8 @@ namespace NonMatching
     const std::vector<Quadrature<dim>> &quadrature_vector,
     const unsigned int                  n_unfiltered_cells)
   {
+    clear();
+
     do_cell_index_compression =
       n_unfiltered_cells != numbers::invalid_unsigned_int;
 
@@ -873,6 +892,8 @@ namespace NonMatching
     const std::vector<ImmersedSurfaceQuadrature<dim>> &quadrature_vector,
     const unsigned int                                 n_unfiltered_cells)
   {
+    clear();
+
     Assert(
       additional_data.use_global_weights == false,
       ExcMessage(
@@ -976,6 +997,8 @@ namespace NonMatching
     const std::vector<std::vector<Quadrature<dim - 1>>> &quadrature_vector,
     const unsigned int                                   n_unfiltered_cells)
   {
+    clear();
+
     do_cell_index_compression =
       n_unfiltered_cells != numbers::invalid_unsigned_int;
 
diff --git a/tests/non_matching/mapping_info_03.cc b/tests/non_matching/mapping_info_03.cc
index cda12083aa..795bad9a17 100644
--- a/tests/non_matching/mapping_info_03.cc
+++ b/tests/non_matching/mapping_info_03.cc
@@ -43,15 +43,14 @@ test()
   FE_Q<dim>     fe(degree);
   MappingQ<dim> mapping(degree);
 
+  NonMatching::MappingInfo<dim>::AdditionalData additional_data;
+  additional_data.use_global_weights = true;
+  NonMatching::MappingInfo<dim> mapping_info(mapping,
+                                             update_JxW_values,
+                                             additional_data);
 
   deallog << "Check JxW faces..." << std::endl;
   {
-    NonMatching::MappingInfo<dim>::AdditionalData additional_data;
-    additional_data.use_global_weights = true;
-    NonMatching::MappingInfo<dim> mapping_info(mapping,
-                                               update_JxW_values,
-                                               additional_data);
-
     // 1) build vector of quadratures
     std::vector<std::vector<Quadrature<dim - 1>>> quad_vec;
     // prescribe JxW (there is no meaning in the actual values, they just have
@@ -96,13 +95,6 @@ test()
 
   deallog << "\n\nCheck JxW cells..." << std::endl;
   {
-    NonMatching::MappingInfo<dim>::AdditionalData additional_data;
-    additional_data.use_global_weights = true;
-    NonMatching::MappingInfo<dim> mapping_info(mapping,
-                                               update_JxW_values,
-                                               additional_data);
-
-
     // 1) build vector of quadratures
     std::vector<Quadrature<dim>> quad_vec;
     // prescribe JxW (there is no meaning in the actual values, they just have
-- 
2.39.5