Clean up logic that is no longer needed

Author: franzpoeschel

include/openPMD/IO/ADIOS/ADIOS2File.hpp

@@ -407,7 +407,7 @@ class ADIOS2File
 
     size_t currentStep();
     void setStepSelection(std::optional<size_t>);
-    [[nodiscard]] std::optional<size_t> stepSelection() const;
+    [[nodiscard]] std::optional<size_t> const &stepSelection() const;
 
     [[nodiscard]] detail::AdiosAttributes const &attributes() const
     {
@@ -431,13 +431,9 @@ class ADIOS2File
     std::optional<adios2::Engine> m_engine; //! ADIOS engine
 
     /*
-     * Not all engines support the CurrentStep() call, so we have to
-     * implement this manually.
-     * Note: We don't use a std::optional<size_t> here since the currentStep
-     * is always being counted.
+     * Used for selecting steps in adios2::Mode::ReadRandomAccesss.
      */
-    size_t m_currentStep = 0;
-    bool useStepSelection = false;
+    std::optional<size_t> m_stepSelection;
     std::optional<size_t> m_max_steps_bp5 = std::make_optional<size_t>(100);
 
     /*

src/IO/ADIOS/ADIOS2File.cpp

@@ -381,28 +381,12 @@ void ADIOS2File::setStepSelection(std::optional<size_t> step)
             "ADIOS2 backend: Cannot only use random-access step selections "
             "when reading without streaming mode.");
     }
-    if (!step.has_value())
-    {
-        m_currentStep = 0;
-        useStepSelection = false;
-    }
-    else
-    {
-        m_currentStep = *step;
-        useStepSelection = true;
-    }
+    m_stepSelection = step;
 }
 
-std::optional<size_t> ADIOS2File::stepSelection() const
+std::optional<size_t> const &ADIOS2File::stepSelection() const
 {
-    if (useStepSelection)
-    {
-        return {m_currentStep};
-    }
-    else
-    {
-        return std::nullopt;
-    }
+    return m_stepSelection;
 }
 
 void ADIOS2File::configure_IO_Read()
@@ -1402,7 +1386,7 @@ ADIOS2File::availableVariablesPrefixed(std::string const &prefix)
 ADIOS2File::AttributeMap_t const &ADIOS2File::availableVariables()
 {
     return m_variables.availableVariables(
-        currentStep(), useStepSelection, m_IO);
+        currentStep(), stepSelection().has_value(), m_IO);
 }
 
 void ADIOS2File::markActive(Writable *writable)