Copy file mpitraits.hh from dune-istl to here. The file disappeared

in dune-istl in revision 1220.  The new file here is intended to be
merged with mpicollectivecommunication.  That will happen in a separate
step.

[[Imported from SVN: r6018]]

dune/common/Makefile.am

@@ -13,7 +13,7 @@ commoninclude_HEADERS = alignment.hh array.hh \
   enumset.hh exceptions.hh fixedarray.hh fmatrix.hh fmatrixev.hh \
   fvector.hh ftraits.hh genericiterator.hh \
   iteratorfacades.hh \
-  misc.hh poolallocator.hh finitestack.hh \
+  misc.hh mpitraits.hh poolallocator.hh finitestack.hh \
   sllist.hh shared_ptr.hh stdstreams.hh timer.hh tuples.hh \
   typetraits.hh precision.hh bigunsignedint.hh \
   gcd.hh lcm.hh configparser.hh propertymap.hh \

dune/common/mpitraits.hh

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+// $Id: mpitraits.hh 1083 2009-09-28 17:13:20Z mblatt $
+#ifndef DUNE_MPITRAITS_HH
+#define DUNE_MPITRAITS_HH
+
+#if HAVE_MPI
+#include "mpi.h"
+#endif
+
+namespace Dune
+{
+  /**
+   * @file
+   * @brief Traits classes for mapping types onto MPI_Datatype.
+   * @author Markus Blatt
+   */
+  /** @addtogroup ISTL_Comm
+   *
+   * @{
+   */
+  /**
+   * @brief A traits class describing the mapping of types onto MPI_Datatypes.
+   *
+   * Specializations exist for the default types.
+   * Specializations should provide a static method
+   * \code
+   * static MPI_Datatype getType();
+   * \endcode
+   */
+  template<typename T>
+  class MPITraits
+  {};
+
+#if HAVE_MPI
+
+  // A Macro for defining traits for the primitive data types
+#define ComposeMPITraits(p,m) \
+  template<> \
+  struct MPITraits<p>{ \
+    static inline MPI_Datatype getType(){ \
+      return m; \
+    } \
+  }
+
+  ComposeMPITraits(char, MPI_CHAR);
+  ComposeMPITraits(unsigned char,MPI_UNSIGNED_CHAR);
+  ComposeMPITraits(short,MPI_SHORT);
+  ComposeMPITraits(unsigned short,MPI_UNSIGNED_SHORT);
+  ComposeMPITraits(int,MPI_INT);
+  ComposeMPITraits(unsigned int,MPI_UNSIGNED);
+  ComposeMPITraits(long,MPI_LONG);
+  ComposeMPITraits(unsigned long,MPI_UNSIGNED_LONG);
+  ComposeMPITraits(float,MPI_FLOAT);
+  ComposeMPITraits(double,MPI_DOUBLE);
+  ComposeMPITraits(long double,MPI_LONG_DOUBLE);
+
+#undef ComposeMPITraits
+
+  template<class K, int n> class FieldVector;
+
+  template<class K, int n>
+  struct MPITraits<FieldVector<K,n> >
+  {
+    static MPI_Datatype datatype;
+    static MPI_Datatype vectortype;
+
+    static inline MPI_Datatype getType()
+    {
+      if(datatype==MPI_DATATYPE_NULL) {
+        MPI_Type_contiguous(n, MPITraits<K>::getType(), &vectortype);
+        MPI_Type_commit(&vectortype);
+        FieldVector<K,n> fvector;
+        MPI_Aint base;
+        MPI_Aint displ;
+        MPI_Address(&fvector, &base);
+        MPI_Address(&(fvector[0]), &displ);
+        displ -= base;
+        int length[1]={1};
+
+        MPI_Type_struct(1, length, &displ, &vectortype, &datatype);
+        MPI_Type_commit(&datatype);
+      }
+      return datatype;
+    }
+
+  };
+
+  template<class K, int n>
+  MPI_Datatype MPITraits<FieldVector<K,n> >::datatype = MPI_DATATYPE_NULL;
+  template<class K, int n>
+  MPI_Datatype MPITraits<FieldVector<K,n> >::vectortype = {MPI_DATATYPE_NULL};
+
+
+  template<int k>
+  class bigunsignedint;
+
+  template<int k>
+  struct MPITraits<bigunsignedint<k> >
+  {
+    static MPI_Datatype datatype;
+    static MPI_Datatype vectortype;
+
+    static inline MPI_Datatype getType()
+    {
+      if(datatype==MPI_DATATYPE_NULL) {
+        MPI_Type_contiguous(bigunsignedint<k>::n, MPITraits<unsigned short>::getType(),
+                            &vectortype);
+        //MPI_Type_commit(&vectortype);
+        bigunsignedint<k> data;
+        MPI_Aint base;
+        MPI_Aint displ;
+        MPI_Address(&data, &base);
+        MPI_Address(&(data.digit), &displ);
+        displ -= base;
+        int length[1]={1};
+        MPI_Type_struct(1, length, &displ, &vectortype, &datatype);
+        MPI_Type_commit(&datatype);
+      }
+      return datatype;
+    }
+  };
+}
+namespace std
+{
+  template<typename T1,typename T2> class pair;
+}
+
+namespace Dune
+{
+  template<int k>
+  MPI_Datatype MPITraits<bigunsignedint<k> >::datatype = MPI_DATATYPE_NULL;
+  template<int k>
+  MPI_Datatype MPITraits<bigunsignedint<k> >::vectortype = MPI_DATATYPE_NULL;
+
+  template<typename T1, typename T2>
+  class MPITraits<std::pair<T1,T2 > >
+  {
+  public:
+    inline static MPI_Datatype getType();
+  private:
+    static MPI_Datatype type;
+  };
+  template<typename T1, typename T2>
+  MPI_Datatype MPITraits<std::pair<T1,T2> >::getType()
+  {
+    if(type==MPI_DATATYPE_NULL) {
+      int length[4];
+      MPI_Aint disp[4];
+      MPI_Datatype types[4] = {MPI_LB, MPITraits<T1>::getType(),
+                               MPITraits<T2>::getType(), MPI_UB};
+      std::pair<T1,T2> rep[2];
+      length[0]=length[1]=length[2]=length[3]=1;
+      MPI_Address(rep, disp); // lower bound of the datatype
+      MPI_Address(&(rep[0].first), disp+1);
+      MPI_Address(&(rep[0].second), disp+2);
+      MPI_Address(rep+1, disp+3); // upper bound of the datatype
+      for(int i=3; i >= 0; --i)
+        disp[i] -= disp[0];
+      MPI_Type_struct(4, length, disp, types, &type);
+      MPI_Type_commit(&type);
+    }
+    return type;
+  }
+
+  template<typename T1, typename T2>
+  MPI_Datatype MPITraits<std::pair<T1,T2> >::type=MPI_DATATYPE_NULL;
+#endif
+
+  /** @} */
+}
+
+#endif