changed: ewoms/common -> opm/models/utils

opm/models/utils/pffgridvector.hh

@@ -0,0 +1,142 @@
+// -*- 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.
+*/
+/*!
+ * \file
+ * \copydoc PffGridVector
+ */
+#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 {
+/*!
+ * \brief A random-access container which stores data attached to a grid's degrees of
+ *        freedom in a prefetch friendly manner.
+ *
+ * This container often reduces the number of cache faults considerably, thus improving
+ * performance. On the flipside data cannot be written to on an individual basis and it
+ * requires significantly more memory than a plain array. PffVector stands for "PreFetch
+ * Friendly Grid Vector".
+ */
+template <class GridView, class Stencil, class Data, class DofMapper>
+class PffGridVector
+{
+    typedef typename GridView::template Codim<0>::Entity Element;
+
+#if DUNE_VERSION_NEWER(DUNE_GRID, 2,6)
+    typedef Dune::MultipleCodimMultipleGeomTypeMapper<GridView> ElementMapper;
+#else
+    typedef Dune::MultipleCodimMultipleGeomTypeMapper<GridView, Dune::MCMGElementLayout> ElementMapper;
+#endif
+
+public:
+    PffGridVector(const GridView& gridView, const DofMapper& dofMapper)
+        : gridView_(gridView)
+#if DUNE_VERSION_NEWER(DUNE_GRID, 2,6)
+        , elementMapper_(gridView_, Dune::mcmgElementLayout())
+#else
+        , elementMapper_(gridView_)
+#endif
+        , 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_);
+        auto elemIt = gridView_.template begin</*codim=*/0>();
+        const auto& elemEndIt = gridView_.template end</*codim=*/0>();
+        for (; elemIt != elemEndIt; ++elemIt) {
+            // set the DOF data pointer for the current element
+            const auto& elem = *elemIt;
+            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_);
+        auto elemIt = gridView_.template begin</*codim=*/0>();
+        const auto& elemEndIt = gridView_.template end</*codim=*/0>();
+        for (; elemIt != elemEndIt; ++elemIt) {
+            stencil.update(*elemIt);
+            result += stencil.numDof();
+        }
+
+        return result;
+    }
+
+    GridView gridView_;
+    ElementMapper elementMapper_;
+    const DofMapper& dofMapper_;
+    std::vector<Data> data_;
+    std::vector<Data*> elemData_;
+};
+
+} // namespace Opm
+
+#endif