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 <memory>
       8             : #include <optional>
       9             : #include <vector>
      10             : 
      11             : #include "DataStructures/DataBox/DataBox.hpp"
      12             : #include "Options/String.hpp"
      13             : #include "Time/EvolutionOrdering.hpp"
      14             : #include "Time/StepChoosers/StepChooser.hpp"
      15             : #include "Time/TimeStepRequest.hpp"
      16             : #include "Utilities/ErrorHandling/Assert.hpp"
      17             : #include "Utilities/Serialization/CharmPupable.hpp"
      18             : #include "Utilities/TMPL.hpp"
      19             : 
      20             : /// \cond
      21             : namespace PUP {
      22             : class er;
      23             : }  // namespace PUP
      24             : namespace Tags {
      25             : struct FixedLtsRatio;
      26             : struct TimeStep;
      27             : }  // namespace Tags
      28             : /// \endcond
      29             : 
      30             : namespace StepChoosers {
      31             : /// Requests a slab size based on the desired step in regions with a
      32             : /// fixed slab fraction.
      33             : ///
      34             : /// \note This StepChooser is not included in the
      35             : /// `standard_step_choosers` list.  Executables using the feature must
      36             : /// include it explicitly in the `factory_creation` struct and add the
      37             : /// `::Tags::FixedLtsRatio` tag to the element DataBox.
      38           1 : class FixedLtsRatio : public StepChooser<StepChooserUse::Slab> {
      39             :  public:
      40             :   /// \cond
      41             :   FixedLtsRatio() = default;
      42             :   explicit FixedLtsRatio(CkMigrateMessage* /*unused*/) {}
      43             :   using PUP::able::register_constructor;
      44             :   WRAPPED_PUPable_decl_template(FixedLtsRatio);  // NOLINT
      45             :   /// \endcond
      46             : 
      47           0 :   struct StepChoosers {
      48           0 :     using type =
      49             :         std::vector<std::unique_ptr<::StepChooser<StepChooserUse::LtsStep>>>;
      50           0 :     static constexpr Options::String help{"LTS step choosers to test"};
      51             :   };
      52             : 
      53           0 :   static constexpr Options::String help{
      54             :       "Requests a slab size based on the desired step in regions with a fixed "
      55             :       "slab fraction."};
      56           0 :   using options = tmpl::list<StepChoosers>;
      57             : 
      58           0 :   explicit FixedLtsRatio(
      59             :       std::vector<std::unique_ptr<::StepChooser<StepChooserUse::LtsStep>>>
      60             :           step_choosers);
      61             : 
      62           0 :   using argument_tags = tmpl::list<::Tags::DataBox>;
      63             : 
      64             :   template <typename DbTags>
      65           0 :   TimeStepRequest operator()(const db::DataBox<DbTags>& box,
      66             :                              const double /*last_step*/) const {
      67             :     const auto& step_ratio = db::get<::Tags::FixedLtsRatio>(box);
      68             :     if (not step_ratio.has_value()) {
      69             :       return {};
      70             :     }
      71             : 
      72             :     const auto& current_step = db::get<::Tags::TimeStep>(box);
      73             :     const evolution_less<double> less{current_step.is_positive()};
      74             : 
      75             :     std::optional<double> size_goal{};
      76             :     std::optional<double> size{};
      77             :     for (const auto& step_chooser : step_choosers_) {
      78             :       const auto step_request =
      79             :           step_chooser->desired_step(current_step.value(), box);
      80             : 
      81             :       if (step_request.size_goal.has_value()) {
      82             :         if (size_goal.has_value()) {
      83             :           *size_goal = std::min(*size_goal, *step_request.size_goal, less);
      84             :         } else {
      85             :           size_goal = step_request.size_goal;
      86             :         }
      87             :       }
      88             :       if (step_request.size.has_value()) {
      89             :         if (size.has_value()) {
      90             :           *size = std::min(*size, *step_request.size, less);
      91             :         } else {
      92             :           size = step_request.size;
      93             :         }
      94             :       }
      95             : 
      96             :       // As of writing (Oct. 2024), no StepChooserUse::LtsStep chooser
      97             :       // sets these.
      98             :       ASSERT(not(step_request.end.has_value() or
      99             :                  step_request.size_hard_limit.has_value() or
     100             :                  step_request.end_hard_limit.has_value()),
     101             :              "Unhandled field set by StepChooser.  Please file a bug "
     102             :              "containing the options passed to FixedLtsRatio.");
     103             :     }
     104             : 
     105             :     if (size_goal.has_value()) {
     106             :       *size_goal *= *step_ratio;
     107             :     }
     108             :     if (size.has_value()) {
     109             :       *size *= *step_ratio;
     110             :       if (size_goal.has_value() and less(*size_goal, *size)) {
     111             :         // Not allowed to request a goal and a bigger step.
     112             :         size.reset();
     113             :       }
     114             :     }
     115             : 
     116             :     return {.size_goal = size_goal, .size = size};
     117             :   }
     118             : 
     119           1 :   bool uses_local_data() const override;
     120           1 :   bool can_be_delayed() const override;
     121             : 
     122             :   template <typename F>
     123           0 :   void for_each_step_chooser(F&& f) const {
     124             :     for (const auto& step_chooser : step_choosers_) {
     125             :       f(*step_chooser);
     126             :     }
     127             :   }
     128             : 
     129           0 :   void pup(PUP::er& p) override;
     130             : 
     131             :  private:
     132             :   std::vector<std::unique_ptr<::StepChooser<StepChooserUse::LtsStep>>>
     133           0 :       step_choosers_;
     134             : };
     135             : }  // namespace StepChoosers