pffgridvector.hh

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// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*
  This file is part of the Open Porous Media project (OPM).
 
  OPM is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.
 
  OPM is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
 
  You should have received a copy of the GNU General Public License
  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
 
  Consult the COPYING file in the top-level source directory of this
  module for the precise wording of the license and the list of
  copyright holders.
*/
#ifndef EWOMS_PFF_GRID_VECTOR_HH
#define EWOMS_PFF_GRID_VECTOR_HH
 
#include <opm/models/utils/prefetch.hh>
 
#include <dune/grid/common/mcmgmapper.hh>
#include <dune/common/version.hh>
 
#include <vector>
 
namespace Opm {
template <class GridView, class Stencil, class Data, class DofMapper>
class PffGridVector
{
    using Element = typename GridView::template Codim<0>::Entity;
 
    using ElementMapper = Dune::MultipleCodimMultipleGeomTypeMapper<GridView>;
 
public:
    PffGridVector(const GridView& gridView, const DofMapper& dofMapper)
        : gridView_(gridView)
        , elementMapper_(gridView_, Dune::mcmgElementLayout())
        , dofMapper_(dofMapper)
    { }
 
    template <class DistFn>
    void update(const DistFn& distFn)
    {
        unsigned numElements = gridView_.size(/*codim=*/0);
        unsigned numLocalDofs = computeNumLocalDofs_();
 
        elemData_.resize(numElements);
        data_.resize(numLocalDofs);
 
        // update the pointers for the element data: for this, we need to loop over the
        // whole grid and update a stencil for each element
        Data *curElemDataPtr = &data_[0];
        Stencil stencil(gridView_, dofMapper_);
        for (const auto& elem : elements(gridView_)) {
            // set the DOF data pointer for the current element
            unsigned elemIdx = elementMapper_.index(elem);
            elemData_[elemIdx] = curElemDataPtr;
 
            stencil.update(elem);
            unsigned numDof = stencil.numDof();
            for (unsigned localDofIdx = 0; localDofIdx < numDof; ++ localDofIdx)
                distFn(curElemDataPtr[localDofIdx], stencil, localDofIdx);
 
            // update the element data pointer to make it point to the beginning of the
            // data for DOFs of the next element
            curElemDataPtr += numDof;
        }
    }
 
    void prefetch(const Element& elem) const
    {
        unsigned elemIdx = elementMapper_.index(elem);
 
        // we use 0 as the temporal locality, because it is reasonable to assume that an
        // entry will only be accessed once.
        ::Opm::prefetch</*temporalLocality=*/0>(elemData_[elemIdx]);
    }
 
    const Data& get(const Element& elem, unsigned localDofIdx) const
    {
        unsigned elemIdx = elementMapper_.index(elem);
        return elemData_[elemIdx][localDofIdx];
    }
 
private:
    unsigned computeNumLocalDofs_() const
    {
        unsigned result = 0;
 
        // loop over the whole grid and sum up the number of local DOFs of all Stencils
        Stencil stencil(gridView_, dofMapper_);
        for (const auto& elem : elements(gridView_)) {
            stencil.update(elem);
            result += stencil.numDof();
        }
 
        return result;
    }
 
    GridView gridView_;
    ElementMapper elementMapper_;
    const DofMapper& dofMapper_;
    std::vector<Data> data_;
    std::vector<Data*> elemData_;
};
 
} // namespace Opm
 
#endif