Line data    Source code

       1           0 : // Distributed under the MIT License.
       2             : // See LICENSE.txt for details.
       3             : 
       4             : #pragma once
       5             : 
       6             : #include <algorithm>
       7             : #include <cstddef>
       8             : #include <memory>
       9             : #include <optional>
      10             : #include <string>
      11             : #include <typeinfo>
      12             : #include <unordered_map>
      13             : #include <vector>
      14             : 
      15             : #include "DataStructures/DataBox/DataBox.hpp"
      16             : #include "Options/Auto.hpp"
      17             : #include "Options/String.hpp"
      18             : #include "Time/EvolutionOrdering.hpp"
      19             : #include "Time/RequestsStepperErrorTolerances.hpp"
      20             : #include "Time/StepChoosers/StepChooser.hpp"
      21             : #include "Time/StepperErrorTolerances.hpp"
      22             : #include "Time/TimeStepRequest.hpp"
      23             : #include "Utilities/ErrorHandling/Assert.hpp"
      24             : #include "Utilities/ErrorHandling/Error.hpp"
      25             : #include "Utilities/Serialization/CharmPupable.hpp"
      26             : #include "Utilities/StdHelpers.hpp"
      27             : #include "Utilities/TMPL.hpp"
      28             : 
      29             : /// \cond
      30             : namespace PUP {
      31             : class er;
      32             : }  // namespace PUP
      33             : namespace Tags {
      34             : struct FixedLtsRatio;
      35             : struct TimeStep;
      36             : }  // namespace Tags
      37             : namespace domain::Tags {
      38             : template <size_t VolumeDim>
      39             : struct Element;
      40             : }  // namespace domain::Tags
      41             : namespace evolution::dg::Tags {
      42             : template <size_t Dim>
      43             : struct EqualRateRegions;
      44             : }  // namespace evolution::dg::Tags
      45             : /// \endcond
      46             : 
      47           0 : namespace evolution::dg::StepChoosers {
      48             : /// Requests a slab size based on the desired step in regions with a
      49             : /// fixed slab fraction.
      50             : ///
      51             : /// \note This StepChooser is not included in the
      52             : /// `standard_step_choosers` list.  Executables using the feature must
      53             : /// include it explicitly in the `factory_creation` struct and add the
      54             : /// `::Tags::FixedLtsRatio` tag to the element DataBox.
      55             : template <size_t Dim>
      56           1 : class FixedLtsRatio : public StepChooser<StepChooserUse::Slab>,
      57             :                       public RequestsStepperErrorTolerances {
      58             :  public:
      59             :   /// \cond
      60             :   FixedLtsRatio() = default;
      61             :   explicit FixedLtsRatio(CkMigrateMessage* /*unused*/) {}
      62             :   using PUP::able::register_constructor;
      63             :   WRAPPED_PUPable_decl_template(FixedLtsRatio);  // NOLINT
      64             :   /// \endcond
      65             : 
      66           0 :   struct StepChoosers {
      67           0 :     using type =
      68             :         std::vector<std::unique_ptr<::StepChooser<StepChooserUse::LtsStep>>>;
      69           0 :     static constexpr Options::String help{"LTS step choosers to test"};
      70             :   };
      71             : 
      72           0 :   struct Regions {
      73           0 :     using type =
      74             :         Options::Auto<std::vector<std::string>, Options::AutoLabel::All>;
      75           0 :     static constexpr Options::String help{"Regions to adjust based on"};
      76             :   };
      77             : 
      78           0 :   static constexpr Options::String help{
      79             :       "Requests a slab size based on the desired step in regions with a fixed "
      80             :       "slab fraction."};
      81           0 :   using options = tmpl::list<StepChoosers, Regions>;
      82             : 
      83           0 :   explicit FixedLtsRatio(
      84             :       std::vector<std::unique_ptr<::StepChooser<StepChooserUse::LtsStep>>>
      85             :           step_choosers,
      86             :       std::optional<std::vector<std::string>> regions);
      87             : 
      88           0 :   using argument_tags = tmpl::list<::Tags::DataBox>;
      89             : 
      90             :   template <typename DbTags>
      91           0 :   TimeStepRequest operator()(const db::DataBox<DbTags>& box,
      92             :                              const double /*last_step*/) const {
      93             :     const auto& step_ratio = db::get<::Tags::FixedLtsRatio>(box);
      94             :     if (not step_ratio.has_value()) {
      95             :       return {};
      96             :     }
      97             : 
      98             :     if (regions_.has_value()) {
      99             :       const auto element_id = db::get<domain::Tags::Element<Dim>>(box).id();
     100             :       const auto& equal_rate_regions =
     101             :           db::get<Tags::EqualRateRegions<Dim>>(box);
     102             :       const auto& region_map = equal_rate_regions.regions();
     103             :       bool active = false;
     104             :       for (const auto& region_name : *regions_) {
     105             :         const auto region_it = region_map.find(region_name);
     106             :         if (region_it == region_map.end()) {
     107             :           ERROR_NO_TRACE("Unknown region name in FixedLtsRatio: "
     108             :                          << region_name
     109             :                          << ".  Known regions: " << keys_of(region_map));
     110             :         }
     111             :         if (equal_rate_regions.is_in_region(region_it->second, element_id)) {
     112             :           active = true;
     113             :           // Don't break here so we check the remaining names for validity.
     114             :         }
     115             :       }
     116             :       if (not active) {
     117             :         return {};
     118             :       }
     119             :     }
     120             : 
     121             :     const auto& current_step = db::get<::Tags::TimeStep>(box);
     122             :     const evolution_less<double> less{current_step.is_positive()};
     123             : 
     124             :     std::optional<double> size_goal{};
     125             :     std::optional<double> size{};
     126             :     for (const auto& step_chooser : step_choosers_) {
     127             :       const auto step_request =
     128             :           step_chooser->desired_step(current_step.value(), box);
     129             : 
     130             :       if (step_request.size_goal.has_value()) {
     131             :         if (size_goal.has_value()) {
     132             :           *size_goal = std::min(*size_goal, *step_request.size_goal, less);
     133             :         } else {
     134             :           size_goal = step_request.size_goal;
     135             :         }
     136             :       }
     137             :       if (step_request.size.has_value()) {
     138             :         if (size.has_value()) {
     139             :           *size = std::min(*size, *step_request.size, less);
     140             :         } else {
     141             :           size = step_request.size;
     142             :         }
     143             :       }
     144             : 
     145             :       // As of writing (Oct. 2024), no StepChooserUse::LtsStep chooser
     146             :       // sets these.
     147             :       ASSERT(not(step_request.end.has_value() or
     148             :                  step_request.size_hard_limit.has_value() or
     149             :                  step_request.end_hard_limit.has_value()),
     150             :              "Unhandled field set by StepChooser.  Please file a bug "
     151             :              "containing the options passed to FixedLtsRatio.");
     152             :     }
     153             : 
     154             :     if (size_goal.has_value()) {
     155             :       *size_goal *= *step_ratio;
     156             :     }
     157             :     if (size.has_value()) {
     158             :       *size *= *step_ratio;
     159             :       if (size_goal.has_value() and less(*size_goal, *size)) {
     160             :         // Not allowed to request a goal and a bigger step.
     161             :         size.reset();
     162             :       }
     163             :     }
     164             : 
     165             :     return {.size_goal = size_goal, .size = size};
     166             :   }
     167             : 
     168           1 :   bool uses_local_data() const override;
     169           1 :   bool can_be_delayed() const override;
     170           1 :   bool must_set_step_size() const override;
     171             : 
     172           1 :   std::unordered_map<std::type_index, StepperErrorTolerances> tolerances()
     173             :       const override;
     174             : 
     175           0 :   void pup(PUP::er& p) override;
     176             : 
     177             :  private:
     178             :   std::vector<std::unique_ptr<::StepChooser<StepChooserUse::LtsStep>>>
     179           0 :       step_choosers_;
     180           0 :   std::optional<std::vector<std::string>> regions_;
     181             : };
     182             : }  // namespace evolution::dg::StepChoosers