Merge pull request #1257 from LLNL/tupek/refactor_checkpoint_load_fro…

…m_disk

Refactor state loading to reduce chances of future bug being added.

src/serac/physics/base_physics.cpp

@@ -331,7 +331,7 @@ void BasePhysics::saveSummary(axom::sidre::DataStore& datastore, const double t)
   }
 }
 
-FiniteElementState BasePhysics::loadCheckpointedState(const std::string& state_name, int cycle) const
+FiniteElementState BasePhysics::loadCheckpointedState(const std::string& state_name, int cycle)
 {
   if (checkpoint_to_disk_) {
     // See if the requested cycle has been checkpointed previously
@@ -356,16 +356,21 @@ FiniteElementState BasePhysics::loadCheckpointedState(const std::string& state_n
   return checkpoint_states_.at(state_name)[static_cast<size_t>(cycle)];
 }
 
-std::unordered_map<std::string, FiniteElementState> BasePhysics::getCheckpointedStates(int cycle_to_load) const
+void BasePhysics::loadCheckpointedStatesFromDisk(int cycle_to_load)
+{
+  std::vector<FiniteElementState*> previous_states_ptrs;
+  for (const auto& state_name : stateNames()) {
+    previous_states_ptrs.emplace_back(const_cast<FiniteElementState*>(&state(state_name)));
+  }
+  StateManager::loadCheckpointedStates(cycle_to_load, previous_states_ptrs);
+}
+
+std::unordered_map<std::string, FiniteElementState> BasePhysics::getCheckpointedStates(int cycle_to_load)
 {
   std::unordered_map<std::string, FiniteElementState> previous_states_map;
-  std::vector<FiniteElementState*>                    previous_states_ptrs;
 
   if (checkpoint_to_disk_) {
-    for (const auto& state_name : stateNames()) {
-      previous_states_ptrs.emplace_back(const_cast<FiniteElementState*>(&state(state_name)));
-    }
-    StateManager::loadCheckpointedStates(cycle_to_load, previous_states_ptrs);
+    loadCheckpointedStatesFromDisk(cycle_to_load);
     for (const auto& state_name : stateNames()) {
       previous_states_map.emplace(state_name, state(state_name));
     }

src/serac/physics/base_physics.hpp

@@ -396,6 +396,13 @@ class BasePhysics {
    */
   virtual void outputStateToDisk(std::optional<std::string> paraview_output_dir = {}) const;
 
+  /**
+   * @brief load checkpointed states from disk into states array
+   *
+   * @param cycle The cycle to retrieve state from
+   */
+  void loadCheckpointedStatesFromDisk(int cycle);
+
   /**
    * @brief Accessor for getting a single named finite element state primal solution from the physics modules at a given
    * checkpointed cycle index
@@ -404,7 +411,7 @@ class BasePhysics {
    * @param cycle The cycle to retrieve state from
    * @return The named primal Finite Element State
    */
-  FiniteElementState loadCheckpointedState(const std::string& state_name, int cycle) const;
+  FiniteElementState loadCheckpointedState(const std::string& state_name, int cycle);
 
   /**
    * @brief Accessor for getting a single named finite element dual solution from the physics modules at a given
@@ -415,7 +422,7 @@ class BasePhysics {
    * @return The named Finite Element Dual
    */
   virtual FiniteElementDual loadCheckpointedDual([[maybe_unused]] const std::string& state_name,
-                                                 [[maybe_unused]] int                cycle) const
+                                                 [[maybe_unused]] int                cycle)
   {
     SLIC_ERROR_ROOT(axom::fmt::format("loadCheckpointedDual not enabled in physics module {}", name_));
     return *duals_[0];
@@ -486,7 +493,7 @@ class BasePhysics {
    * @param cycle The cycle to retrieve state from
    * @return A map containing the primal field names and their associated FiniteElementStates at the requested cycle
    */
-  std::unordered_map<std::string, FiniteElementState> getCheckpointedStates(int cycle) const;
+  std::unordered_map<std::string, FiniteElementState> getCheckpointedStates(int cycle);
 
   /// @brief Name of the physics module
   std::string name_ = {};

src/serac/physics/solid_mechanics.hpp

@@ -762,7 +762,7 @@ class SolidMechanics<order, dim, Parameters<parameter_space...>, std::integer_se
   }
 
   /// @overload
-  FiniteElementDual loadCheckpointedDual(const std::string& dual_name, int cycle) const override
+  FiniteElementDual loadCheckpointedDual(const std::string& dual_name, int cycle) override
   {
     if (dual_name == "reactions") {
       auto checkpointed_sol = getCheckpointedStates(cycle);