Move cartesian grid related stuff to a separate file

src/cartesian_grid.hpp

@@ -0,0 +1,91 @@
+#pragma once
+
+/*
+  Copyright (C) 2016 Finnish Meteorological Institute
+  Copyright (C) 2016-2024 CSC -IT Center for Science
+
+  This file is part of fsgrid
+
+  fsgrid 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 3 of the License, or
+  (at your option) any later version.
+
+  fsgrid 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 fsgrid.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tools.hpp"
+
+#include <array>
+#include <cstdint>
+#include <mpi.h>
+
+namespace fsgrid {
+struct CartesianGrid {
+private:
+   using FsSize_t = FsGridTools::FsSize_t;
+   using FsIndex_t = FsGridTools::FsIndex_t;
+   using LocalID = FsGridTools::LocalID;
+   using GlobalID = FsGridTools::GlobalID;
+   using Task_t = FsGridTools::Task_t;
+
+public:
+   //!< Global size of the simulation space, in cells
+   std::array<FsSize_t, 3> globalSize = {};
+   //!< Information about whether a given direction is periodic
+   std::array<bool, 3> periodic = {};
+   //!< Rank in the parent communicator
+   int32_t parentRank = -1;
+   //!< Size of the parent communicator
+   int32_t parentSize = 0;
+   //!< The number of fs ranks
+   int32_t size = 0;
+   //!< Colour that identifies fs ranks
+   int32_t colourFs = MPI_UNDEFINED;
+   //!< Colour that identifies non-fs ranks
+   int32_t colourAux = MPI_UNDEFINED;
+   //!< Number of tasks in each direction
+   std::array<Task_t, 3> numTasksPerDim = {};
+   //! MPI Cartesian communicator used in this grid
+   MPI_Comm cartesian3d = MPI_COMM_NULL;
+   //!< This task's rank in the communicator
+   int32_t rank = -1;
+   //!< This task's position in the 3d task grid
+   std::array<Task_t, 3> taskPosition = {};
+   //!< Local size of simulation space handled by this task (without ghost cells)
+   std::array<FsIndex_t, 3> localSize = {};
+   //!< Offset of the local coordinate system against the global one
+   std::array<FsIndex_t, 3> localStart = {};
+   //!< Local size of simulation space handled by this task (including ghost cells)
+   std::array<FsIndex_t, 3> storageSize = {};
+
+   CartesianGrid(std::array<FsSize_t, 3> globalSize, MPI_Comm parentComm, std::array<bool, 3> periodic,
+                 const std::array<Task_t, 3>& decomposition, int32_t stencilSize)
+       : globalSize(globalSize), periodic(periodic), parentRank(FsGridTools::getCommRank(parentComm)),
+         parentSize(FsGridTools::getCommSize(parentComm)), size(FsGridTools::getNumFsGridProcs(parentSize)),
+         colourFs(FsGridTools::computeColourFs(parentRank, size)),
+         colourAux(FsGridTools::computeColourAux(parentRank, parentSize, size)),
+         numTasksPerDim(FsGridTools::computeNumTasksPerDim(globalSize, decomposition, size, stencilSize)),
+         cartesian3d(FsGridTools::createCartesianCommunicator(parentComm, colourFs, colourAux, parentRank,
+                                                              numTasksPerDim, periodic)),
+         rank(FsGridTools::getCartesianRank(colourFs, cartesian3d)),
+         taskPosition(FsGridTools::getTaskPosition(cartesian3d)),
+         localSize(FsGridTools::calculateLocalSize(globalSize, numTasksPerDim, taskPosition, rank, stencilSize)),
+         localStart(FsGridTools::calculateLocalStart(globalSize, numTasksPerDim, taskPosition)),
+         storageSize(FsGridTools::calculateStorageSize(globalSize, localSize, stencilSize)) {}
+
+   CartesianGrid() {}
+
+   void finalize() {
+      if (cartesian3d != MPI_COMM_NULL) {
+         FSGRID_MPI_CHECK(MPI_Comm_free(&cartesian3d), "Failed to free MPI comm");
+      }
+   }
+};
+}