TsqrRandomizer_Tpetra_MultiVector.hpp

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#ifndef __TSQR_Trilinos_Randomizer_Tpetra_MultiVector_hpp
#define __TSQR_Trilinos_Randomizer_Tpetra_MultiVector_hpp


#include "TsqrTypeAdaptor_Tpetra_MultiVector_SerialNode.hpp"
#ifdef HAVE_KOKKOS_TBB
#  include "TsqrTypeAdaptor_Tpetra_MultiVector_TBBNode.hpp"
#endif // HAVE_KOKKOS_TBB
#include "TsqrCommFactory_Tpetra.hpp"

#include <stdexcept>
#include <sstream>


namespace TSQR {
  namespace Trilinos {

    template< class S, class LO, class GO, class NodeType, class Gen >
    class TpetraRandomizer :
      public Randomizer< S, LO, GO, 
       Tpetra::MultiVector< S, LO, GO, NodeType >,
       Gen >
    {
    public:
      // mfh 14 Jul 2010: I'm uncomfortable naming this "MV" because
      // the base class already has MV defined in it.  I don't want to
      // go all circular (MV -> multivector_type -> MV).  TMV here is
      // just a way to make the base_type typedef fit on one line.
      typedef Tpetra::MultiVector< S, LO, GO, NodeType > TMV;

      // The C++ compiler needs help inheriting typedefs, when both
      // the base class and the derived class are templated.
      typedef Randomizer< double, int, int, TMV, Gen > base_type;
      typedef typename base_type::multivector_type multivector_type;
      typedef typename base_type::local_ordinal_type local_ordinal_type;
      typedef typename base_type::scalar_type scalar_type;

      typedef typename base_type::normalgen_ptr normalgen_ptr;
      typedef typename base_type::comm_ptr comm_ptr;
      typedef typename base_type::ordinal_messenger_ptr ordinal_messenger_ptr;
      typedef typename base_type::scalar_messenger_ptr scalar_messenger_ptr;

      TpetraRandomizer (const multivector_type& mv,
      const normalgen_ptr& pGen)
      {
  init (mv, pGen);
      }

    private:
      virtual void
      fetchDims (const multivector_type& A,
     local_ordinal_type& nrowsLocal, 
     local_ordinal_type& ncols, 
     local_ordinal_type& LDA) const
      {
  nrowsLocal = A.getLocalLength();
  ncols = A.getNumVectors();
  if (nrowsLocal < ncols)
    {
      std::ostringstream os;
      os << "The local component of the input matrix has fewer row"
        "s (" << nrowsLocal << ") than columns (" << ncols << ").  "
        "TSQR::Trilinos::TpetraRandomizer does not support this case.";
      throw std::runtime_error (os.str());
    }
  if (! A.isConstantStride())
    {
      // FIXME (mfh 14 June 2010) Storage of A uses nonconstant
      // stride internally, but that doesn't necessarily mean we
      // can't run TSQR.  It depends on what get1dViewNonConst()
      // returns.  If it's copied and packed into a matrix with
      // constant stride, then we are free to run TSQR.
      std::ostringstream os;
      os << "TSQR::Trilinos::TpetraRandomizer does not support "
        "Tpetra::MultiVector inputs that do not have constant stride.";
      throw std::runtime_error (os.str());
    }
  LDA = A.getStride();
      }

      virtual Teuchos::ArrayRCP< scalar_type > 
      fetchNonConstView (multivector_type& A) const
      {
  // This won't be efficient if the entries of A live in a
  // different memory space (e.g., GPU node), but it will be
  // correct for any Tpetra::MultiVector type.
  return A.get1dViewNonConst();
      }

      virtual void
      fetchMessengers (const multivector_type& mv,
           scalar_messenger_ptr& pScalarMessenger,
           ordinal_messenger_ptr& pOrdinalMessenger) const
      {
  typedef TpetraCommFactory< S, LO, GO, NodeType > comm_factory_type;
  comm_ptr pComm = mv.getMap()->getComm();
  comm_factory_type factory;
  factory.makeMessengers (pComm, pScalarMessenger, pOrdinalMessenger);
      }
    };
  } // namespace Trilinos
} // namespace TSQR

#endif // __TSQR_Trilinos_Randomizer_Tpetra_MultiVector_hpp