Track if garbage collection is necessary.

This is useful for precondition checks in client code.

src/OpenVolumeMesh/Core/GeometryKernel.hh

@@ -107,6 +107,9 @@ public:
 
     virtual void collect_garbage()
     {
+        if (!TopologyKernelT::needs_garbage_collection())
+            return;
+
         if (TopologyKernelT::fast_deletion_enabled()) {
             TopologyKernelT::collect_garbage();
             vertices_.resize(TopologyKernel::n_vertices());

src/OpenVolumeMesh/Core/TopologyKernel.cc

@@ -64,7 +64,8 @@ TopologyKernel::TopologyKernel() :
     e_bottom_up_(true),
     f_bottom_up_(true),
     deferred_deletion(true),
-    fast_deletion(true)
+    fast_deletion(true),
+    needs_garbage_collection_(false)
 {
 }
 
@@ -719,7 +720,7 @@ CellIter TopologyKernel::delete_cell(const CellHandle& _h) {
  */
 void TopologyKernel::collect_garbage()
 {
-    if (!deferred_deletion_enabled())
+    if (!deferred_deletion_enabled() || !needs_garbage_collection_)
         return; // nothing todo
 
     deferred_deletion = false;
@@ -754,6 +755,7 @@ void TopologyKernel::collect_garbage()
 
 
     deferred_deletion = true;
+    needs_garbage_collection_ = false;
 
 }
 
@@ -920,6 +922,7 @@ VertexIter TopologyKernel::delete_vertex_core(const VertexHandle& _h) {
 
     if (deferred_deletion_enabled())
     {
+        needs_garbage_collection_ = true;
         vertex_deleted_[h.idx()] = true;
 //        deleted_vertices_.push_back(h);
 
@@ -1047,6 +1050,7 @@ EdgeIter TopologyKernel::delete_edge_core(const EdgeHandle& _h) {
 
     if (deferred_deletion_enabled())
     {
+        needs_garbage_collection_ = true;
         edge_deleted_[h.idx()] = true;
 //        deleted_edges_.push_back(h);
 
@@ -1231,6 +1235,7 @@ FaceIter TopologyKernel::delete_face_core(const FaceHandle& _h) {
 
     if (deferred_deletion_enabled())
     {
+        needs_garbage_collection_ = true;
         face_deleted_[h.idx()] = true;
 //        deleted_faces_.push_back(h);
 
@@ -1389,6 +1394,7 @@ CellIter TopologyKernel::delete_cell_core(const CellHandle& _h) {
 
     if (deferred_deletion_enabled())
     {
+        needs_garbage_collection_ = true;
         cell_deleted_[h.idx()] = true;
 //        deleted_cells_.push_back(h);
 //        deleted_cells_set.insert(h);

src/OpenVolumeMesh/Core/TopologyKernel.hh

@@ -925,6 +925,10 @@ public:
         return HalfFaceHandle(_h.idx() - 1);
     }
 
+    bool inline needs_garbage_collection() const {
+        return needs_garbage_collection_;
+    }
+
 protected:
 
     // List of edges
@@ -940,6 +944,7 @@ protected:
     std::vector<bool> edge_deleted_;
     std::vector<bool> face_deleted_;
     std::vector<bool> cell_deleted_;
+    bool needs_garbage_collection_;
 
 };