Begin rework of Gmsh reader [ci-skip]

- use PEGTL to parse file structure
- improve reading performance (mmap+std::from_chars)
- better error handling

* multiple references per entity still buggy
* remains to add 4.1 format support

src/language/modules/WriterModule.cpp

@@ -8,7 +8,6 @@
 #include <language/utils/CheckpointResumeRepository.hpp>
 #include <language/utils/TypeDescriptor.hpp>
 #include <mesh/Connectivity.hpp>
-#include <mesh/GmshReader.hpp>
 #include <mesh/ItemArrayVariant.hpp>
 #include <mesh/ItemValueVariant.hpp>
 #include <mesh/Mesh.hpp>

src/mesh/GmshReader.hpp

@@ -6,10 +6,7 @@
 #include <mesh/RefId.hpp>
 #include <utils/Array.hpp>
 
-#include <array>
-#include <fstream>
 #include <map>
-#include <memory>
 #include <string>
 #include <vector>
 
@@ -70,52 +67,62 @@ class GmshReader : public MeshBuilderBase
 
   struct GmshData
   {
+    struct Format
+    {
+      double version    = 0;
+      bool binary       = false;
+      int size_of_int   = 0;
+      bool littleendian = false;   //
+    };
+
+    Format format;
+
     /**
      * Gmsh format provides a numbered, none ordrered and none dense
      * vertices list, this stores the number of read vertices.
      */
-    std::vector<int> __verticesNumbers;
+    Array<int> __verticesNumbers;
 
     Array<R3> __vertices;
 
     using Point = unsigned int;
     Array<Point> __points;
-    std::vector<int> __points_ref;
+    std::vector<std::vector<int>> __points_ref;
     std::vector<int> __points_number;
 
     using Edge = TinyVector<2, unsigned int>;
     Array<Edge> __edges;
-    std::vector<int> __edges_ref;
+    std::vector<std::vector<int>> __edges_ref;
     std::vector<int> __edges_number;
 
     using Triangle = TinyVector<3, unsigned int>;
     Array<Triangle> __triangles;
-    std::vector<int> __triangles_ref;
+    std::vector<std::vector<int>> __triangles_ref;
     std::vector<int> __triangles_number;
 
     using Quadrangle = TinyVector<4, unsigned int>;
     Array<Quadrangle> __quadrangles;
-    std::vector<int> __quadrangles_ref;
+    std::vector<std::vector<int>> __quadrangles_ref;
     std::vector<int> __quadrangles_number;
 
     using Tetrahedron = TinyVector<4, unsigned int>;
     Array<Tetrahedron> __tetrahedra;
-    std::vector<int> __tetrahedra_ref;
+    std::vector<std::vector<int>> __tetrahedra_ref;
     std::vector<int> __tetrahedra_number;
 
     using Pyramid = TinyVector<5, unsigned int>;
     Array<Pyramid> __pyramids;
-    std::vector<int> __pyramids_ref;
+    std::vector<std::vector<int>> __pyramids_ref;
     std::vector<int> __pyramids_number;
 
     using Prism = TinyVector<6, unsigned int>;
     Array<Prism> __prisms;
-    std::vector<int> __prisms_ref;
+    std::vector<std::vector<int>> __prisms_ref;
     std::vector<int> __prisms_number;
 
     using Hexahedron = TinyVector<8, unsigned int>;
     Array<Hexahedron> __hexahedra;
-    std::vector<int> __hexahedra_ref;
+    std::vector<std::vector<int>> __hexahedra_ref;
     std::vector<int> __hexahedra_number;
 
     /**
@@ -137,7 +144,7 @@ class GmshReader : public MeshBuilderBase
     /**
      * References
      */
-    std::vector<int> __references;
+    std::vector<std::vector<int>> __references;
 
     /**
      * References
@@ -148,138 +155,16 @@ class GmshReader : public MeshBuilderBase
   };
 
  private:
-  std::ifstream m_fin;
   const std::string m_filename;
 
   GmshData m_mesh_data;
 
-  /**
-   * Stores the number of nodes associated to each primitive
-   *
-   */
-  std::vector<int> __numberOfPrimitiveNodes;
-
-  /**
-   * Array of boolean describing gmsh supported primitives by ff3d
-   *
-   */
-  std::array<bool, 15> __supportedPrimitives;
-
-  /**
-   * Primitives names according to there number
-   *
-   */
-  std::map<int, std::string> __primitivesNames;
-
-  int
-  _getInteger()
-  {
-    int i;
-    m_fin >> i;
-
-    return i;
-  }
-
-  double
-  _getReal()
-  {
-    double d;
-    m_fin >> d;
-
-    return d;
-  }
-
   /**
    * Adapts gmsh data to ff3d's structures
    *
    */
   void __proceedData();
 
-  /**
-   * Reads data in format 2.2
-   *
-   */
-  void __readGmshFormat2_2();
-
-  /**
-   * List of allowed keyword in mesh file
-   *
-   */
-  enum KeywordType
-  {
-    // gmsh 2.2
-    MESHFORMAT,
-    ENDMESHFORMAT,
-    NODES,
-    ENDNODES,
-    ELEMENTS,
-    ENDELEMENTS,
-    PHYSICALNAMES,
-    ENDPHYSICALNAMES,
-    PERIODIC,
-    ENDPERIODIC,
-
-    Unknown,
-    EndOfFile
-  };
-
-  /**
-   * List of known keywords
-   *
-   */
-  using KeywordList = std::map<std::string, int>;
-
-  KeywordList __keywordList; /**< The keyword list */
-
-  /**
-   * Type for keyword
-   *
-   */
-  using Keyword = std::pair<std::string, int>;
-
-  /**
-   * Skips next comments if exists
-   *
-   */
-  void __skipComments();
-
-  /**
-   * Reads the next keyword and returns its token
-   *
-   * @return KeywordToken
-   */
-  Keyword __nextKeyword();
-
-  /**
-   * get list of vertices
-   *
-   */
-  void __getVertices();
-
-  /**
-   * Read list of vertices
-   *
-   */
-  void __readVertices();
-
-  /**
-   * Read all elements in format 2.0
-   *
-   */
-  void __readElements2_2();
-
-  /**
-   * Reads physical names
-   *
-   */
-  void __readPhysicalNames2_2();
-
-  /**
-   * Reads periodic
-   *
-   */
-  void __readPeriodic2_2();
-
  public:
   GmshReader(const std::string& filename);
   ~GmshReader() = default;