From aa9e7cf34d217de7e53fe9fbefdcacbb72ab97dc Mon Sep 17 00:00:00 2001
From: Giles Bathgate <giles.bathgate@gmail.com>
Date: Thu, 10 Mar 2022 18:24:07 +0000
Subject: [PATCH] Reserve hashtable size in polygon_mesh_to_nef_3

---
 Nef_3/include/CGAL/Nef_3/SNC_simplify.h          | 2 ++
 Nef_3/include/CGAL/Nef_3/SNC_structure.h         | 4 ++++
 Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h | 2 +-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/Nef_3/include/CGAL/Nef_3/SNC_simplify.h b/Nef_3/include/CGAL/Nef_3/SNC_simplify.h
index 1b882bf5717..20e09259dce 100644
--- a/Nef_3/include/CGAL/Nef_3/SNC_simplify.h
+++ b/Nef_3/include/CGAL/Nef_3/SNC_simplify.h
@@ -545,6 +545,8 @@ class SNC_simplify_base : public SNC_decorator<SNC_structure> {
       Unique_hash_map< SFace_handle, UFH_sface>& hash,
       Union_find< SFace_handle>& uf ) {
     Unique_hash_map< SHalfedge_handle, bool> linked(false, this->sncp()->number_of_shalfedges());
+    this->sncp()->reserve_sm_boundary_items(this->sncp()->number_of_sfaces());
+
     SNC_decorator D(*this->sncp());
     SHalfedge_iterator e;
     CGAL_forall_shalfedges(e, *this->sncp()) {
diff --git a/Nef_3/include/CGAL/Nef_3/SNC_structure.h b/Nef_3/include/CGAL/Nef_3/SNC_structure.h
index 4c58e22fbed..ee6be285256 100644
--- a/Nef_3/include/CGAL/Nef_3/SNC_structure.h
+++ b/Nef_3/include/CGAL/Nef_3/SNC_structure.h
@@ -462,6 +462,10 @@ public:
     return *this;
   }
 
+  void reserve_sm_boundary_items(Size_type n) {
+    sm_boundary_item_.reserve(n);
+  }
+
   void clear_boundary() {
     boundary_item_.clear(boost::none);
     sm_boundary_item_.clear(boost::none);
diff --git a/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h b/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
index dea41f6eb00..b32a885e90d 100644
--- a/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
+++ b/Nef_3/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h
@@ -205,7 +205,7 @@ void polygon_mesh_to_nef_3(PolygonMesh& P, SNC_structure& S, FaceIndexMap fimap,
   Face_graph_index_adder<typename SNC_structure::Items,
                  PolygonMesh, SNC_structure,HalfedgeIndexMap> index_adder(P,himap);
 
-
+  S.reserve_sm_boundary_items(num_vertices(P));
   for(vertex_descriptor pv : vertices(P) ) {
 
     typename boost::property_traits<PMap>::reference npv = get(pmap,pv);