restart_data.h

/*  ______________________________________________________________________
 *
 *  ExaDG - High-Order Discontinuous Galerkin for the Exa-Scale
 *
 *  Copyright (C) 2021 by the ExaDG authors
 *
 *  This program 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.
 *
 *  This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
 *  ______________________________________________________________________
 */
 
#ifndef EXADG_TIME_INTEGRATION_RESTART_DATA_H_
#define EXADG_TIME_INTEGRATION_RESTART_DATA_H_
 
// C/C++
#include <limits>
 
// deal.II
#include <deal.II/base/conditional_ostream.h>
 
// ExaDG
#include <exadg/grid/grid_data.h>
#include <exadg/incompressible_navier_stokes/user_interface/enum_types.h>
#include <exadg/utilities/numbers.h>
#include <exadg/utilities/print_functions.h>
 
namespace ExaDG
{
struct DeserializationParameters
{
  DeserializationParameters()
    : degree(dealii::numbers::invalid_unsigned_int),
      degree_u(dealii::numbers::invalid_unsigned_int),
      degree_p(dealii::numbers::invalid_unsigned_int),
      mapping_degree(dealii::numbers::invalid_unsigned_int),
      consider_mapping_write(false),
      triangulation_type(TriangulationType::Serial),
      spatial_discretization(IncNS::SpatialDiscretization::L2)
  {
  }
 
  void
  print(dealii::ConditionalOStream const & pcout) const
  {
    pcout << "  Deserialization parameters:" << std::endl;
    print_parameter(pcout, "Polynomial degree `degree`", degree);
    print_parameter(pcout, "Polynomial degree `degree_u`", degree_u);
    print_parameter(pcout, "Polynomial degree `degree_p`", degree_p);
    print_parameter(pcout, "Mapping degree", mapping_degree);
    print_parameter(pcout, "Consider mapping", consider_mapping_write);
    print_parameter(pcout, "Triangulation type", triangulation_type);
    print_parameter(pcout, "Spatial discretization", spatial_discretization);
  }
 
  // Polynomial degrees of the finite elements used at serialization.
  unsigned int degree;
  unsigned int degree_u;
  unsigned int degree_p;
 
  // Polynomial degree of the mapping used at serialization.
  unsigned int mapping_degree;
 
  // The mapping is stored during serialization as a displacement vector.
  bool consider_mapping_write;
 
  // Triangulation type used at serialization.
  TriangulationType triangulation_type;
 
  // Spatial discretization used at serialization. Relevant for incompressible Navier-Stokes only.
  IncNS::SpatialDiscretization spatial_discretization;
};
 
struct RestartData
{
  RestartData()
    : write_restart(false),
      n_snapshots_keep(2),
      interval_time(std::numeric_limits<double>::max()),
      interval_time_start(std::numeric_limits<double>::lowest()),
      interval_time_end(std::numeric_limits<double>::max()),
      interval_wall_time(std::numeric_limits<double>::max()),
      interval_time_steps(std::numeric_limits<unsigned int>::max()),
      directory_coarse_triangulation("./output/"),
      directory("./output/"),
      filename("restart"),
      counter(1),
      discretization_identical(false),
      consider_mapping_write(false),
      consider_mapping_read_source(false),
      consider_restart_time_in_mesh_movement_function(true),
      rpe_rtree_level(0),
      rpe_tolerance_unit_cell(1e-12),
      rpe_enforce_unique_mapping(false)
  {
  }
 
  void
  print(dealii::ConditionalOStream const & pcout) const
  {
    pcout << "  Restart:" << std::endl;
    print_parameter(pcout, "Write restart", write_restart);
 
    if(write_restart == true)
    {
      print_parameter(pcout, "Interval physical time", interval_time);
      print_parameter(pcout, "Interval physical time window start", interval_time_start);
      print_parameter(pcout, "Interval physical time window end", interval_time_end);
      print_parameter(pcout, "Interval wall time", interval_wall_time);
      print_parameter(pcout, "Interval time steps", interval_time_steps);
      print_parameter(pcout, "Directory coarse triangulation", directory_coarse_triangulation);
      print_parameter(pcout, "Directory", directory);
      print_parameter(pcout, "Filename", filename);
    }
  }
 
  bool
  do_restart(double const           wall_time,
             double const           time,
             types::time_step const time_step_number,
             bool const             reset_counter) const
  {
    // After a restart, the counter is reset to 1, but time = current_time - start time != 0 after a
    // restart. Hence, we have to explicitly reset the counter in that case. There is nothing to do
    // if the restart is controlled by the wall time or the time_step_number because these
    // variables are reinitialized after a restart anyway.
    if(reset_counter)
      counter += int((time + 1.e-10) / interval_time);
 
    bool const trigger_restart_base = wall_time > interval_wall_time * counter or
                                      time > interval_time * counter or
                                      time_step_number > interval_time_steps * counter;
 
    // Additionally use the physical time window.
    bool const trigger_restart =
      trigger_restart_base and time >= interval_time_start and time <= interval_time_end;
 
    if(trigger_restart)
      ++counter;
 
    return trigger_restart;
  }
 
  bool write_restart;
 
  // Number of snapshots to keep
  unsigned int n_snapshots_keep;
 
  // physical time interval between serializations
  double interval_time;
 
  // physical time interval in which serialization is enabled
  double interval_time_start;
  double interval_time_end;
 
  // wall time in seconds (= hours * 3600)
  double interval_wall_time;
 
  // number of time steps after which to write restart
  unsigned int interval_time_steps;
 
  // directory for restart files: coarse triangulation and snapshot data can be stored separately.
  std::string directory_coarse_triangulation;
  std::string directory;
 
  // filename for restart files
  std::string filename;
 
  // counter needed do decide when to write restart
  mutable unsigned int counter;
 
  // The discretization used when writing the restart data was identical to the current one.
  // Note that this includes the finite element, uniform and adaptive refinement, and the
  // `TriangulationType`, *but* one might consider a different number of MPI ranks for
  // `dealii::parallel::distributed::Triangulation` without the need for the otherwise
  // necessary global projection.
  bool discretization_identical;
 
  // Attach the mapping as a displacement vector when *writing* the restart data.
  bool consider_mapping_write;

 
  // Reconstruct the mapping for the serialized grid (`source`) in the grid-to-grid projection at
  // restart. Note that the grid use at restart is always considered as defined in the applciation.
  bool consider_mapping_read_source;
 
  // When creating a mapping function via `create_mesh_movement_function()`, use the `start_time` or
  // the `time` serialized to evaluate the mapping at restart.
  bool consider_restart_time_in_mesh_movement_function;
 
  // Parameters for `dealii::Utilities::MPI::RemotePointEvaluation<dim>::RemotePointEvaluation`
  // used for grid-to-grid projection.
  unsigned int rpe_rtree_level;
  double       rpe_tolerance_unit_cell;
  bool         rpe_enforce_unique_mapping;
};
 
} // namespace ExaDG
 
#endif /* EXADG_TIME_INTEGRATION_RESTART_DATA_H_ */