Introduce more flexible storeChunk() syntax, use to add ADIOS2 memory selection

CMakeLists.txt

@@ -456,6 +456,7 @@ set(CORE_SOURCE
         src/Format.cpp
         src/Iteration.cpp
         src/IterationEncoding.cpp
+        src/LoadStoreChunk.cpp
         src/Mesh.cpp
         src/ParticlePatches.cpp
         src/ParticleSpecies.cpp
@@ -467,6 +468,7 @@ set(CORE_SOURCE
         src/WriteIterations.cpp
         src/auxiliary/Date.cpp
         src/auxiliary/Filesystem.cpp
+        src/auxiliary/Future.cpp
         src/auxiliary/JSON.cpp
         src/auxiliary/Mpi.cpp
         src/backend/Attributable.cpp

include/openPMD/Dataset.hpp

@@ -34,6 +34,12 @@ namespace openPMD
 using Extent = std::vector<std::uint64_t>;
 using Offset = std::vector<std::uint64_t>;
 
+struct MemorySelection
+{
+    Offset offset;
+    Extent extent;
+};
+
 class Dataset
 {
     friend class RecordComponent;

include/openPMD/Datatype.hpp

@@ -321,7 +321,8 @@ template <typename T>
 inline constexpr Datatype determineDatatype(T &&val)
 {
     (void)val; // don't need this, it only has a name for Doxygen
-    using T_stripped = std::remove_cv_t<std::remove_reference_t<T>>;
+    using T_stripped =
+        std::remove_extent_t<std::remove_cv_t<std::remove_reference_t<T>>>;
     if constexpr (auxiliary::IsPointer_v<T_stripped>)
     {
         return determineDatatype<auxiliary::IsPointer_t<T_stripped>>();

include/openPMD/IO/ADIOS/ADIOS2File.hpp

@@ -20,11 +20,13 @@
  */
 #pragma once
 
+#include "openPMD/Dataset.hpp"
 #include "openPMD/IO/ADIOS/ADIOS2Auxiliary.hpp"
 #include "openPMD/IO/AbstractIOHandler.hpp"
 #include "openPMD/IO/IOTask.hpp"
 #include "openPMD/IO/InvalidatableFile.hpp"
 #include "openPMD/config.hpp"
+#include <optional>
 
 #if openPMD_HAVE_ADIOS2
 #include <adios2.h>
@@ -106,6 +108,7 @@ struct BufferedUniquePtrPut
     std::string name;
     Offset offset;
     Extent extent;
+    std::optional<MemorySelection> memorySelection;
     UniquePtrWithLambda<void> data;
     Datatype dtype = Datatype::UNDEFINED;
 

include/openPMD/IO/ADIOS/ADIOS2IOHandler.hpp

@@ -20,9 +20,11 @@
  */
 #pragma once
 
+#include "openPMD/Dataset.hpp"
 #include "openPMD/Error.hpp"
 #include "openPMD/IO/ADIOS/ADIOS2Auxiliary.hpp"
 #include "openPMD/IO/ADIOS/ADIOS2FilePosition.hpp"
+#include "openPMD/IO/ADIOS/macros.hpp"
 #include "openPMD/IO/AbstractIOHandler.hpp"
 #include "openPMD/IO/AbstractIOHandlerImpl.hpp"
 #include "openPMD/IO/AbstractIOHandlerImplCommon.hpp"
@@ -426,6 +428,7 @@ class ADIOS2IOHandlerImpl
     adios2::Variable<T> verifyDataset(
         Offset const &offset,
         Extent const &extent,
+        std::optional<MemorySelection> const &memorySelection,
         adios2::IO &IO,
         std::string const &varName)
     {
@@ -507,13 +510,26 @@ class ADIOS2IOHandlerImpl
         var.SetSelection(
             {adios2::Dims(offset.begin(), offset.end()),
              adios2::Dims(extent.begin(), extent.end())});
+
+        if (memorySelection.has_value())
+        {
+            var.SetMemorySelection(
+                {adios2::Dims(
+                     memorySelection->offset.begin(),
+                     memorySelection->offset.end()),
+                 adios2::Dims(
+                     memorySelection->extent.begin(),
+                     memorySelection->extent.end())});
+        }
+
         return var;
     }
 
     struct
     {
         bool noGroupBased = false;
         bool blosc2bp5 = false;
+        bool memorySelection = false;
     } printedWarningsAlready;
 }; // ADIOS2IOHandlerImpl
 

include/openPMD/IO/ADIOS/macros.hpp

@@ -34,6 +34,26 @@
 #define openPMD_HAVE_ADIOS2_BP5 0
 #endif
 
+namespace detail
+{
+template <typename Variable, typename SFINAE = void>
+struct CanTheMemorySelectionBeReset
+{
+    static constexpr bool value = false;
+};
+
+template <typename Variable>
+struct CanTheMemorySelectionBeReset<
+    Variable,
+    decltype(std::declval<Variable>().SetMemorySelection())>
+{
+    static constexpr bool value = true;
+};
+} // namespace detail
+
+constexpr bool CanTheMemorySelectionBeReset =
+    detail::CanTheMemorySelectionBeReset<adios2::Variable<int>>::value;
+
 #else
 
 #define openPMD_HAS_ADIOS_2_8 0

include/openPMD/IO/IOTask.hpp

@@ -33,6 +33,7 @@
 #include <cstddef>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <variant>
@@ -436,6 +437,7 @@ struct OPENPMDAPI_EXPORT Parameter<Operation::WRITE_DATASET>
 
     Extent extent = {};
     Offset offset = {};
+    std::optional<MemorySelection> memorySelection = std::nullopt;
     Datatype dtype = Datatype::UNDEFINED;
     auxiliary::WriteBuffer data;
 };