[MaL/LA/Eigen] LinearSorverOptionsParser templ. spezialisation.

MathLib/LinAlg/Eigen/LinearSolverOptionsParser.h

+/**
+ * \file
+ * \copyright
+ * Copyright (c) 2012-2021, 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 <memory>
+#include <vector>
+
+#include "BaseLib/ConfigTree.h"
+#include "BaseLib/Error.h"
+#include "EigenOption.h"
+#include "MathLib/LinAlg/LinearSolverOptions.h"
+#include "MathLib/LinAlg/LinearSolverOptionsParser.h"
+
+namespace MathLib
+{
+template <>
+struct LinearSolverOptionsParser<EigenLinearSolver> final
+{
+    /// The method parses the linear solver options for Eigen.
+    /// @param prefix the prefix for the linear solver to distinguish different
+    /// linear solvers for instance in the staggered schema
+    /// @param solver_config the part of the property tree (usually created from
+    /// the linear solver section in the project file)
+    /// @return the first item of the returned tuple is the solver prefix as
+    /// string, the second item are all the options as an EigenOption object
+    std::tuple<std::string, EigenOption> parseNameAndOptions(
+        std::string const& prefix,
+        BaseLib::ConfigTree const* const solver_config) const
+    {
+        if (!solver_config)
+        {
+            return {prefix, EigenOption{}};
+        }
+
+        ignoreOtherLinearSolvers(*solver_config, "eigen");
+        //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen}
+        auto const config = solver_config->getConfigSubtreeOptional("eigen");
+        if (!config)
+        {
+            OGS_FATAL(
+                "OGS was compiled with Eigen but the config section in the "
+                "project file seems to be invalid");
+        }
+
+        EigenOption options;
+
+        if (auto solver_type =
+                //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen__solver_type}
+            config->getConfigParameterOptional<std::string>("solver_type"))
+        {
+            options.solver_type =
+                MathLib::EigenOption::getSolverType(*solver_type);
+        }
+        if (auto precon_type =
+                //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen__precon_type}
+            config->getConfigParameterOptional<std::string>("precon_type"))
+        {
+            options.precon_type =
+                MathLib::EigenOption::getPreconType(*precon_type);
+        }
+        if (auto error_tolerance =
+                //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen__error_tolerance}
+            config->getConfigParameterOptional<double>("error_tolerance"))
+        {
+            options.error_tolerance = *error_tolerance;
+        }
+        if (auto max_iteration_step =
+                //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen__max_iteration_step}
+            config->getConfigParameterOptional<int>("max_iteration_step"))
+        {
+            options.max_iterations = *max_iteration_step;
+        }
+        if (auto scaling =
+                //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen__scaling}
+            config->getConfigParameterOptional<bool>("scaling"))
+        {
+#ifdef USE_EIGEN_UNSUPPORTED
+            options.scaling = *scaling;
+#else
+            OGS_FATAL(
+                "The code is not compiled with the Eigen unsupported modules. "
+                "scaling is not available.");
+#endif
+        }
+        if (auto restart =
+                //! \ogs_file_param{prj__linear_solvers__linear_solver__eigen__restart}
+            config->getConfigParameterOptional<int>("restart"))
+        {
+#ifdef USE_EIGEN_UNSUPPORTED
+            options.restart = *restart;
+#else
+            OGS_FATAL(
+                "The code is not compiled with the Eigen unsupported modules. "
+                "GMRES/GMRES option restart is not available.");
+#endif
+        }
+        return {prefix, options};
+    }
+};
+
+}  // namespace MathLib