Rework simplex tree options

src/Persistent_cohomology/example/plain_homology.cpp

@@ -16,13 +16,13 @@
 #include <cstdint>  // for std::uint8_t
 
 /* We could perfectly well use the default Simplex_tree<> (which uses
- * Simplex_tree_options_full_featured), the following simply demonstrates
+ * Simplex_tree_options_default), the following simply demonstrates
  * how to save on storage by not storing a filtration value.  */
 
-struct MyOptions : Gudhi::Simplex_tree_options_full_featured {
-  // Implicitly use 0 as filtration value for all simplices
-  static const bool store_filtration = false;
-  // The persistence algorithm needs this
+struct MyOptions : Gudhi::Simplex_tree_options_minimal {
+  // Implicitly use 0 as filtration value for all simplices - inherited from Simplex_tree_options_minimal
+  // static const bool store_filtration = false;
+  // However the persistence algorithm needs this
   static const bool store_key = true;
   // I have few vertices
   typedef short Vertex_handle;

src/Persistent_cohomology/test/betti_numbers_unit_test.cpp

@@ -12,7 +12,7 @@
 #include <gudhi/Simplex_tree.h>
 #include <gudhi/Persistent_cohomology.h>
 
-struct MiniSTOptions : Gudhi::Simplex_tree_options_full_featured {
+struct MiniSTOptions : Gudhi::Simplex_tree_options_minimal {
   // Implicitly use 0 as filtration value for all simplices
   static const bool store_filtration = false;
   // The persistence algorithm needs this

src/Simplex_tree/benchmark/simplex_tree_cofaces_benchmark.cpp

@@ -81,14 +81,23 @@ void benchmark_stars_computation(int nb_vertices) {
   std::clog << benchmark_cofaces << std::endl;
 }
 
-struct Simplex_tree_options_stable_simplex_handles {
+struct Stree_basic_cofaces_options {
   typedef Gudhi::linear_indexing_tag Indexing_tag;
   typedef int Vertex_handle;
   typedef double Filtration_value;
   typedef std::uint32_t Simplex_key;
   static const bool store_key = true;
   static const bool store_filtration = true;
   static const bool contiguous_vertices = false;
+  static const bool link_nodes_by_label = false;
+  static const bool stable_simplex_handles = false;
+};
+
+struct Stree_fast_cofaces_options : Stree_basic_cofaces_options {
+  static const bool link_nodes_by_label = true;
+};
+
+struct Stree_fast_cofaces_stable_simplex_handles_options : Stree_basic_cofaces_options {
   static const bool link_nodes_by_label = true;
   static const bool stable_simplex_handles = true;
 };
@@ -105,13 +114,13 @@ int main(int argc, char *argv[]) {
     nb_vertices = atoi(argv[1]);
 
   std::clog << "** Without cofaces computation optimization" << std::endl;
-  benchmark_stars_computation<Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_full_featured>>(nb_vertices);
+  benchmark_stars_computation<Gudhi::Simplex_tree<Stree_basic_cofaces_options>>(nb_vertices);
 
   std::clog << "** With cofaces computation optimization" << std::endl;
-  benchmark_stars_computation<Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_cofaces>>(nb_vertices);
+  benchmark_stars_computation<Gudhi::Simplex_tree<Stree_fast_cofaces_options>>(nb_vertices);
 
   std::clog << "** With cofaces computation optimization and stable simplex handles" << std::endl;
-  benchmark_stars_computation<Gudhi::Simplex_tree<Simplex_tree_options_stable_simplex_handles> >(nb_vertices);
+  benchmark_stars_computation<Gudhi::Simplex_tree<Stree_fast_cofaces_stable_simplex_handles_options> >(nb_vertices);
 
   return EXIT_SUCCESS;
 }

src/Simplex_tree/concept/SimplexTreeOptions.h

@@ -8,28 +8,34 @@
  *      - YYYY/MM Author: Description of the modification
  */
 
-/** \brief Concept of the template parameter for the class `Gudhi::Simplex_tree<SimplexTreeOptions>`.
+/** @brief Concept of the template parameter for the class `Gudhi::Simplex_tree<SimplexTreeOptions>`.
  *
- * One model for this is `Gudhi::Simplex_tree_options_full_featured`. If you want to provide your own, it is recommended that you derive from it and override some parts instead of writing a class from scratch.
+ * A model for this is `Gudhi::Simplex_tree_options_full_featured` or  `Gudhi::Simplex_tree_options_minimal`.
+ * If you want to provide your own, it is recommended that you derive from it and override some parts instead of
+ * writing a class from scratch.
  */
 struct SimplexTreeOptions {
-  /// Forced for now.
+  /** @brief Forced for now. */
   typedef IndexingTag Indexing_tag;
-  /// Must be a signed integer type. It admits a total order <.
+  /** @brief Must be a signed integer type. It admits a total order <. */
   typedef VertexHandle Vertex_handle;
-  /// Must be comparable with operator<.
+  /** @brief Must be comparable with operator<. */
   typedef FiltrationValue Filtration_value;
-  /// Must be an integer type.
+  /** @brief Must be an integer type. */
   typedef SimplexKey Simplex_key;
-  /// If true, each simplex has extra storage for one `Simplex_key`. Necessary for `Persistent_cohomology`.
+  /** @brief If true, each simplex has extra storage for one `Simplex_key`. Necessary for `Persistent_cohomology`. */
   static const bool store_key;
-  /// If true, each simplex has extra storage for one `Filtration_value`, and this value is propagated by operations like `Gudhi::Simplex_tree::expansion`. Without it, `Persistent_cohomology` degenerates to computing usual (non-persistent) cohomology.
+  /** @brief If true, each simplex has extra storage for one `Filtration_value`, and this value is propagated by
+   * operations like `Gudhi::Simplex_tree::expansion`. Without it, `Persistent_cohomology` degenerates to computing
+   * usual (non-persistent) cohomology.
+   */
   static const bool store_filtration;
-  /// If true, the list of vertices present in the complex must always be 0, ..., num_vertices-1, without any hole.
+
+  /** @brief If true, the list of vertices present in the complex must always be 0, ..., num_vertices-1, without any hole. */
   static constexpr bool contiguous_vertices;
-  /// If true, the lists of `Node` with same label are stored to enhance cofaces and stars access.
+  /** @brief If true, the lists of `Node` with same label are stored to enhance cofaces and stars access. */
   static const bool link_nodes_by_label;
-  /// If true, Simplex_handle will not be invalidated after insertions or removals.
+  /** @brief If true, Simplex_handle will not be invalidated after insertions or removals. */
   static const bool stable_simplex_handles;
 };
 

src/Simplex_tree/example/mini_simplex_tree.cpp

@@ -12,11 +12,10 @@
 #include <iostream>
 #include <initializer_list>
 
-struct MyOptions : Gudhi::Simplex_tree_options_full_featured {
-  // Not doing persistence, so we don't need those
-  static const bool store_key = false;
-  static const bool store_filtration = false;
-  // I have few vertices
+// With Gudhi::Simplex_tree_options_minimal filtration values are not stored and persistence cannot be computed.
+// I can still improve the memory footprint
+struct MyOptions : Gudhi::Simplex_tree_options_minimal {
+  // As I have few vertices
   typedef short Vertex_handle;
 };
 

src/Simplex_tree/include/gudhi/Simplex_tree.h

@@ -16,11 +16,11 @@
 #ifndef SIMPLEX_TREE_H_
 #define SIMPLEX_TREE_H_
 
+#include <gudhi/Simplex_tree/simplex_tree_options.h>
 #include <gudhi/Simplex_tree/Simplex_tree_node_explicit_storage.h>
 #include <gudhi/Simplex_tree/Simplex_tree_siblings.h>
 #include <gudhi/Simplex_tree/Simplex_tree_iterators.h>
 #include <gudhi/Simplex_tree/Simplex_tree_star_simplex_iterators.h>
-#include <gudhi/Simplex_tree/indexing_tag.h>
 #include <gudhi/Simplex_tree/serialization_utils.h>  // for Gudhi::simplex_tree::de/serialize_trivial
 #include <gudhi/Simplex_tree/hooks_simplex_base.h>
 
@@ -53,7 +53,6 @@
 #include <limits>  // Inf
 #include <initializer_list>
 #include <algorithm>  // for std::max
-#include <cstdint>  // for std::uint32_t
 #include <iterator>  // for std::distance
 #include <type_traits>  // for std::conditional
 #include <unordered_map>
@@ -79,8 +78,6 @@ namespace Gudhi {
  */
 enum class Extended_simplex_type {UP, DOWN, EXTRA};
 
-struct Simplex_tree_options_full_featured;
-
 /**
  * \class Simplex_tree Simplex_tree.h gudhi/Simplex_tree.h
  * \brief Simplex Tree data structure for representing simplicial complexes.
@@ -94,7 +91,7 @@ struct Simplex_tree_options_full_featured;
  *
  */
 
-template<typename SimplexTreeOptions = Simplex_tree_options_full_featured>
+template<typename SimplexTreeOptions = Simplex_tree_options_default>
 class Simplex_tree {
  public:
   typedef SimplexTreeOptions Options;
@@ -2597,56 +2594,6 @@ std::istream& operator>>(std::istream & is, Simplex_tree<T...> & st) {
   return is;
 }
 
-/** Model of SimplexTreeOptions.
- * 
- * Maximum number of simplices to compute persistence is <CODE>std::numeric_limits<std::uint32_t>::max()</CODE>
- * (about 4 billions of simplices). */
-struct Simplex_tree_options_full_featured {
-  typedef linear_indexing_tag Indexing_tag;
-  typedef int Vertex_handle;
-  typedef double Filtration_value;
-  typedef std::uint32_t Simplex_key;
-  static const bool store_key = true;
-  static const bool store_filtration = true;
-  static const bool contiguous_vertices = false;
-  static const bool link_nodes_by_label = false;
-  static const bool stable_simplex_handles = false;
-};
-
-/** Model of SimplexTreeOptions, faster than `Simplex_tree_options_full_featured` but note the unsafe
- * `contiguous_vertices` option.
- * 
- * Maximum number of simplices to compute persistence is <CODE>std::numeric_limits<std::uint32_t>::max()</CODE>
- * (about 4 billions of simplices). */
-struct Simplex_tree_options_fast_persistence {
-  typedef linear_indexing_tag Indexing_tag;
-  typedef int Vertex_handle;
-  typedef float Filtration_value;
-  typedef std::uint32_t Simplex_key;
-  static const bool store_key = true;
-  static const bool store_filtration = true;
-  static const bool contiguous_vertices = true;
-  static const bool link_nodes_by_label = false;
-  static const bool stable_simplex_handles = false;
-};
-
-/** Model of SimplexTreeOptions, faster cofaces than `Simplex_tree_options_full_featured`, note the
- * `link_nodes_by_label` option.
- * 
- * Maximum number of simplices to compute persistence is <CODE>std::numeric_limits<std::uint32_t>::max()</CODE>
- * (about 4 billions of simplices). */
-struct Simplex_tree_options_fast_cofaces {
-  typedef linear_indexing_tag Indexing_tag;
-  typedef int Vertex_handle;
-  typedef double Filtration_value;
-  typedef std::uint32_t Simplex_key;
-  static const bool store_key = true;
-  static const bool store_filtration = true;
-  static const bool contiguous_vertices = false;
-  static const bool link_nodes_by_label = true;
-  static const bool stable_simplex_handles = false;
-};
-
 /** @}*/  // end addtogroup simplex_tree
 
 }  // namespace Gudhi

src/Simplex_tree/include/gudhi/Simplex_tree/simplex_tree_options.h

@@ -0,0 +1,96 @@
+/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ *    Author(s):       Vincent Rouvreau
+ *
+ *    Copyright (C) 2023 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#ifndef SIMPLEX_TREE_SIMPLEX_TREE_OPTIONS_H_
+#define SIMPLEX_TREE_SIMPLEX_TREE_OPTIONS_H_
+
+#include <gudhi/Simplex_tree/indexing_tag.h>
+
+#include <cstdint>
+
+namespace Gudhi {
+
+/** \addtogroup simplex_tree 
+ * Pre-defined options for the Simplex_tree.
+ *  @{
+ */
+
+/** Model of SimplexTreeOptions.
+ * 
+ * Default options version of the Simplex_tree.
+ * 
+ * Maximum number of simplices to compute persistence is <CODE>std::numeric_limits<std::uint32_t>::max()</CODE>
+ * (about 4 billions of simplices). */
+struct Simplex_tree_options_default {
+  typedef linear_indexing_tag Indexing_tag;
+  typedef int Vertex_handle;
+  typedef double Filtration_value;
+  typedef std::uint32_t Simplex_key;
+  static const bool store_key = true;
+  static const bool store_filtration = true;
+  static const bool contiguous_vertices = false;
+  static const bool link_nodes_by_label = false;
+  static const bool stable_simplex_handles = false;
+};
+
+/** Model of SimplexTreeOptions.
+ * 
+ * Maximum number of simplices to compute persistence is <CODE>std::numeric_limits<std::uint32_t>::max()</CODE>
+ * (about 4 billions of simplices). */
+struct Simplex_tree_options_full_featured {
+  typedef linear_indexing_tag Indexing_tag;
+  typedef int Vertex_handle;
+  typedef double Filtration_value;
+  typedef std::uint32_t Simplex_key;
+  static const bool store_key = true;
+  static const bool store_filtration = true;
+  static const bool contiguous_vertices = false;
+  static const bool link_nodes_by_label = true;
+  static const bool stable_simplex_handles = true;
+};
+
+/** Model of SimplexTreeOptions.
+ * 
+ * Minimal version of the Simplex_tree. No filtration values are stored and it is impossible to compute persistence
+ * with these options. */
+struct Simplex_tree_options_minimal {
+  typedef linear_indexing_tag Indexing_tag;
+  typedef int Vertex_handle;
+  typedef double Filtration_value;
+  typedef std::uint32_t Simplex_key;
+  static const bool store_key = false;
+  static const bool store_filtration = false;
+  static const bool contiguous_vertices = false;
+  static const bool link_nodes_by_label = false;
+  static const bool stable_simplex_handles = false;
+};
+
+/** @private @brief Model of SimplexTreeOptions, faster than `Simplex_tree_options_default` but note the unsafe
+ * `contiguous_vertices` option.
+ * 
+ * Maximum number of simplices to compute persistence is <CODE>std::numeric_limits<std::uint32_t>::max()</CODE>
+ * (about 4 billions of simplices). */
+struct Simplex_tree_options_fast_persistence {
+  typedef linear_indexing_tag Indexing_tag;
+  typedef int Vertex_handle;
+  typedef float Filtration_value;
+  typedef std::uint32_t Simplex_key;
+  static const bool store_key = true;
+  static const bool store_filtration = true;
+  static const bool contiguous_vertices = true;
+  static const bool link_nodes_by_label = false;
+  static const bool stable_simplex_handles = false;
+};
+
+/** @}*/  // end addtogroup simplex_tree
+
+}  // namespace Gudhi
+
+#endif  // SIMPLEX_TREE_SIMPLEX_TREE_OPTIONS_H_

src/Simplex_tree/test/simplex_tree_ctor_and_move_unit_test.cpp

@@ -40,7 +40,7 @@ struct Simplex_tree_options_stable_simplex_handles {
 
 typedef boost::mpl::list<Simplex_tree<>,
                          Simplex_tree<Simplex_tree_options_fast_persistence>,
-                         Simplex_tree<Simplex_tree_options_fast_cofaces>,
+                         Simplex_tree<Simplex_tree_options_full_featured>,
                          Simplex_tree<Simplex_tree_options_stable_simplex_handles> > list_of_tested_variants;
 
 template<typename Simplex_tree>
@@ -202,7 +202,7 @@ std::vector<std::vector<typename Simplex_tree::Vertex_handle>> get_star(Simplex_
 
 BOOST_AUTO_TEST_CASE(simplex_fast_cofaces_rule_of_five) {
   // Only for fast cofaces version to check the data structure for this feature is up to date 
-  using STree = Simplex_tree<Simplex_tree_options_fast_cofaces>;
+  using STree = Simplex_tree<Simplex_tree_options_full_featured>;
   STree st;
 
   st.insert_simplex_and_subfaces({2, 1, 0}, 3.0);