API to retrieve local neighbor indicies of an element added

src/h5core/h5t_retrieve.c

@@ -310,3 +310,22 @@ h5t_get_vertex_coords_by_id (
 	H5_CORE_API_RETURN (H5_SUCCESS);
 }
 
+h5_err_t
+h5t_get_neighbor_indices (
+	h5t_mesh_t* const m,
+	h5_loc_id_t entity_id,
+	h5_loc_idx_t* neighbor_indices
+	) {
+	H5_CORE_API_ENTER (h5_err_t,
+			   "m=%p, entity_id=%llu, neighbor_indices=%p",
+			   m,
+			   (long long unsigned)entity_id,
+			   neighbor_indices);
+	h5_loc_idx_t elem_idx = h5tpriv_get_elem_idx (entity_id);
+	h5_loc_idx_t* indices = h5tpriv_get_loc_elem_neighbor_indices (m, elem_idx);
+	int num_facets = h5tpriv_ref_elem_get_num_facets (m);
+	for (int i = 0; i < num_facets; i++) {
+		neighbor_indices[i] = indices[i];
+	}
+	H5_CORE_API_RETURN (H5_SUCCESS);
+}

src/include/H5Fed_retrieve.h

@@ -173,6 +173,19 @@ H5FedGetVertexIndicesOfEntity (
 	H5_API_RETURN (h5t_get_vertex_indices_of_entity (m, entity_id, vertex_indices));
 }
 
+static inline h5_err_t
+H5FedGetNeighborIndicesOfElement (
+	h5t_mesh_t* const m,
+	h5_loc_id_t entity_id,
+	h5_loc_idx_t* neighbor_indices
+	) {
+	H5_API_ENTER (h5_err_t,
+		      "m=%p, entity_id=%lld, neighbor_indices=%p",
+		      m, (long long)entity_id, neighbor_indices);
+	H5_API_RETURN (h5t_get_neighbor_indices (m, entity_id, neighbor_indices));
+}
+
+
 #ifdef __cplusplus
 }
 #endif

src/include/h5core/h5t_retrieve.h

@@ -78,6 +78,8 @@ h5t_get_vertex_coords_by_index (h5t_mesh_t* const, h5_loc_idx_t, h5_float64_t[3]
 h5_err_t
 h5t_get_vertex_coords_by_id (h5t_mesh_t* const, h5_loc_id_t, h5_float64_t[3]);
 
+h5_err_t
+h5t_get_neighbor_indices (h5t_mesh_t* const, h5_loc_id_t, h5_loc_idx_t*);
 #ifdef __cplusplus
 }
 #endif