Thyra_DetachedVectorView.hpp

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// ***********************************************************************
// 
//    Thyra: Interfaces and Support for Abstract Numerical Algorithms
//                 Copyright (2004) Sandia Corporation
// 
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
// 
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
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// This library is distributed in the hope that it will be useful, but
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//  
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA
// Questions? Contact Michael A. Heroux (maherou@sandia.gov) 
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#include "Thyra_VectorBase.hpp"

#ifndef THYRA_EXPLICIT_VECTOR_VIEW_HPP
#define THYRA_EXPLICIT_VECTOR_VIEW_HPP

namespace Thyra {

template<class Scalar>
class ConstDetachedVectorView {
public:
  ConstDetachedVectorView(
    const Teuchos::RCP<const VectorBase<Scalar> > &v
    ,const Range1D &rng = Range1D(), const bool forceUnitStride = false
    )
    {
      this->initialize(v,rng,forceUnitStride);
    }
  ConstDetachedVectorView( const VectorBase<Scalar>& v, const Range1D &rng = Range1D(), const bool forceUnitStride = false )
    {
      this->initialize(Teuchos::rcp(&v,false),rng,forceUnitStride);
    }
  ~ConstDetachedVectorView()
    {
      if( sv_s_.stride() != sv_.stride() )
        delete [] const_cast<Scalar*>(sv_.values());
      v_->releaseDetachedView(&sv_s_);
    }
  const RTOpPack::ConstSubVectorView<Scalar>& sv() const { return sv_; }
  Teuchos_Index   globalOffset() const { return sv_.globalOffset(); }
  Teuchos_Index   subDim()       const { return sv_.subDim();  }
  const Scalar*     values()       const { return sv_.values();  }
  ptrdiff_t         stride()       const { return sv_.stride();  }
  const Scalar& operator[](Teuchos_Index i) const { return sv_[i]; }
  const Scalar& operator()(Teuchos_Index i) const { return sv_(i); }
private:
  //
  Teuchos::RCP<const VectorBase<Scalar> > v_;
  RTOpPack::ConstSubVectorView<Scalar>  sv_s_;
  RTOpPack::ConstSubVectorView<Scalar>  sv_;
  //
  void initialize(
    const Teuchos::RCP<const VectorBase<Scalar> > &v
    ,const Range1D &rng, const bool forceUnitStride
    )
    {
      v_ = v;
      v_->acquireDetachedView(rng,&sv_s_);
      if( forceUnitStride && sv_s_.stride() != 1 ) {
        Scalar *values = new Scalar[sv_s_.subDim()];
        Teuchos_Index i; const Scalar *sv_v;
        for( sv_v = sv_s_.values(), i=0; i < sv_s_.subDim(); ++i, sv_v += sv_s_.stride() )
          values[i] = *sv_v;
        sv_.initialize(sv_s_.globalOffset(),sv_s_.subDim(),values,1);
      }
      else {
        sv_ = sv_s_;
      }
    }
  // Not defined and not to be called
  ConstDetachedVectorView();
  ConstDetachedVectorView(const ConstDetachedVectorView<Scalar>&);
  ConstDetachedVectorView<Scalar>& operator==(const ConstDetachedVectorView<Scalar>&);
};
 
template<class Scalar>
class DetachedVectorView {
public:
  DetachedVectorView(
    const Teuchos::RCP<VectorBase<Scalar> > &v
    ,const Range1D &rng = Range1D(), const bool forceUnitStride = false
    )
    {
      this->initialize(v,rng,forceUnitStride);
    }
  DetachedVectorView( VectorBase<Scalar>& v, const Range1D &rng = Range1D(), const bool forceUnitStride = false )
    {
      this->initialize(Teuchos::rcp(&v,false),rng,forceUnitStride);
    }
  ~DetachedVectorView()
    {
      if( sv_s_.stride() != sv_.stride() ) {
        Teuchos_Index i; Scalar *sv_v; const Scalar *values;
        for( sv_v = sv_s_.values(), values = sv_.values(), i=0; i < sv_s_.subDim(); ++i, sv_v += sv_s_.stride() )
          *sv_v = *values++;
        delete [] sv_.values();
      }
      v_->commitDetachedView(&sv_s_);
    }
  const RTOpPack::SubVectorView<Scalar>& sv() const { return sv_; }
  Teuchos_Index   globalOffset() const { return sv_.globalOffset(); }
  Teuchos_Index   subDim()       const { return sv_.subDim();  }
  Scalar*           values()       const { return sv_.values();  }
  ptrdiff_t         stride()       const { return sv_.stride();  }
  Scalar& operator[](Teuchos_Index i) const { return sv_[i]; }
  Scalar& operator()(Teuchos_Index i) const { return sv_(i); }
private:
  //
  Teuchos::RCP<VectorBase<Scalar> > v_;
  RTOpPack::SubVectorView<Scalar>  sv_s_;
  RTOpPack::SubVectorView<Scalar>  sv_;
  //
  void initialize(
    const Teuchos::RCP<VectorBase<Scalar> > &v
    ,const Range1D &rng, const bool forceUnitStride
    )
    {
      v_ = v;
      v_->acquireDetachedView(rng,&sv_s_);
      if( forceUnitStride && sv_s_.stride() != 1 ) {
        Scalar *values = new Scalar[sv_s_.subDim()];
        Teuchos_Index i; const Scalar *sv_v;
        for( sv_v = sv_s_.values(), i=0; i < sv_s_.subDim(); ++i, sv_v += sv_s_.stride() )
          values[i] = *sv_v;
        sv_.initialize(sv_s_.globalOffset(),sv_s_.subDim(),values,1);
      }
      else {
        sv_ = sv_s_;
      }
    }
  // Not defined and not to be called
  DetachedVectorView();
  DetachedVectorView(const DetachedVectorView<Scalar>&);
  DetachedVectorView<Scalar>& operator==(const DetachedVectorView<Scalar>&);
};

} // namespace Thyra

#endif // THYRA_EXPLICIT_VECTOR_VIEW_HPP

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