From b235859bccb4e12a5bb56ad15e8be575ba670a10 Mon Sep 17 00:00:00 2001
From: Tobias Meisel <tobias.meisel@ufz.de>
Date: Tue, 15 Dec 2020 13:05:58 +0100
Subject: [PATCH] [MeL/IO] Add generic abstraction layer for parallel and
serial file IO
---
MeshLib/CMakeLists.txt | 5 +++
MeshLib/IO/XDMF/mpi/partition.cpp | 57 +++++++++++++++++++++++++++++
MeshLib/IO/XDMF/partition.h | 19 ++++++++++
MeshLib/IO/XDMF/posix/partition.cpp | 14 +++++++
4 files changed, 95 insertions(+)
create mode 100644 MeshLib/IO/XDMF/mpi/partition.cpp
create mode 100644 MeshLib/IO/XDMF/partition.h
create mode 100644 MeshLib/IO/XDMF/posix/partition.cpp
diff --git a/MeshLib/CMakeLists.txt b/MeshLib/CMakeLists.txt
index 59188234505..24a835276ee 100644
--- a/MeshLib/CMakeLists.txt
+++ b/MeshLib/CMakeLists.txt
@@ -14,6 +14,11 @@ append_source_files(SOURCES IO/Legacy)
append_source_files(SOURCES IO/VtkIO)
if(OGS_USE_XDMF)
append_source_files(SOURCES IO/XDMF)
+ if(OGS_USE_PETSC)
+ append_source_files(SOURCES IO/XDMF/mpi)
+ else()
+ append_source_files(SOURCES IO/XDMF/posix)
+ endif()
endif()
append_source_files(SOURCES MeshQuality)
append_source_files(SOURCES Vtk)
diff --git a/MeshLib/IO/XDMF/mpi/partition.cpp b/MeshLib/IO/XDMF/mpi/partition.cpp
new file mode 100644
index 00000000000..b626e4fc902
--- /dev/null
+++ b/MeshLib/IO/XDMF/mpi/partition.cpp
@@ -0,0 +1,57 @@
+/**
+ * \file
+ * \author Tobias Meisel
+ * \date 2020-12-08
+ * \brief Function specific to execution with MPI!!
+ * \copyright Copyright (c) 2012-2020, OpenGeoSys Community
+ * (http://www.opengeosys.org) Distributed under a Modified BSD License. See
+ * accompanying file LICENSE.txt or http://www.opengeosys.org/project/license
+ */
+
+#include <mpi.h>
+
+#include <deque>
+#include <numeric>
+
+#include "../fileIO.h"
+#include "BaseLib/Logging.h"
+
+namespace MeshLib::IO
+{
+bool isFileManager()
+{
+ int mpi_rank;
+ MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
+ return mpi_rank == 0;
+}
+
+std::pair<std::size_t, std::size_t> getPartitionInfo(std::size_t const size)
+{
+ MPI_Comm const mpi_comm = MPI_COMM_WORLD;
+ int mpi_size;
+ int mpi_rank;
+ MPI_Comm_size(mpi_comm, &mpi_size);
+ MPI_Comm_rank(mpi_comm, &mpi_rank);
+
+ std::vector<std::size_t> partition_sizes;
+ partition_sizes.resize(mpi_size);
+
+ MPI_Allgather(&size,
+ 1,
+ MPI_UNSIGNED_LONG,
+ partition_sizes.data(),
+ 1,
+ MPI_UNSIGNED_LONG,
+ mpi_comm);
+
+ // the first partition's offset is zero, offsets for subsequent
+ // partitions are the accumulated sum of all preceding size (excluding
+ // own size)
+ std::vector<std::size_t> partition_offsets(1, 0);
+ std::partial_sum(partition_sizes.begin(),
+ partition_sizes.end(),
+ back_inserter(partition_offsets));
+
+ return {partition_offsets[mpi_rank], partition_offsets.back()};
+}
+} // namespace MeshLib::IO
diff --git a/MeshLib/IO/XDMF/partition.h b/MeshLib/IO/XDMF/partition.h
new file mode 100644
index 00000000000..95b8b042f99
--- /dev/null
+++ b/MeshLib/IO/XDMF/partition.h
@@ -0,0 +1,19 @@
+/**
+ * \file
+ * \author Tobias Meisel
+ * \date 2020-12-08
+ * \brief Dispatches functions specific to execution plattform (w/o MPI)
+ * \copyright Copyright (c) 2012-2020, OpenGeoSys Community
+ * (http://www.opengeosys.org) Distributed under a Modified BSD License. See
+ * accompanying file LICENSE.txt or http://www.opengeosys.org/project/license
+ */
+
+#pragma once
+
+#include <utility>
+
+namespace MeshLib::IO
+{
+std::pair<std::size_t, std::size_t> getPartitionInfo(std::size_t const size);
+bool isFileManager();
+} // namespace MeshLib::IO
diff --git a/MeshLib/IO/XDMF/posix/partition.cpp b/MeshLib/IO/XDMF/posix/partition.cpp
new file mode 100644
index 00000000000..2a3d98df675
--- /dev/null
+++ b/MeshLib/IO/XDMF/posix/partition.cpp
@@ -0,0 +1,14 @@
+#include "../partition.h"
+
+namespace MeshLib::IO
+{
+bool isFileManager()
+{
+ return true;
+}
+
+std::pair<std::size_t, std::size_t> getPartitionInfo(std::size_t const size)
+{
+ return {0, size};
+}
+} // namespace MeshLib::IO
\ No newline at end of file
--
GitLab