From bf0f7fcd94d0551bf2834eae1599174dde504ad3 Mon Sep 17 00:00:00 2001
From: Bernhard Manfred Gruber <bernhardmgruber@gmail.com>
Date: Wed, 7 Jul 2021 15:42:06 +0200
Subject: [PATCH] allow to configure submappings of OffsetTable

---
 include/llama/DumpMapping.hpp         |  4 +-
 include/llama/mapping/OffsetTable.hpp | 47 +++++++++++++++++++--
 tests/recorddimension.cpp             | 59 ++++++++++++++++++++++++++-
 3 files changed, 102 insertions(+), 8 deletions(-)

diff --git a/include/llama/DumpMapping.hpp b/include/llama/DumpMapping.hpp
index a98e4ff64f..e430405918 100644
--- a/include/llama/DumpMapping.hpp
+++ b/include/llama/DumpMapping.hpp
@@ -139,8 +139,8 @@ namespace llama
             return infos;
         }
 
-        template <typename ArrayDims, typename RecordDim>
-        auto boxesFromMapping(const mapping::OffsetTable<ArrayDims, RecordDim>& mapping)
+        template <typename ArrayDims, typename RecordDim, typename SubMappings>
+        auto boxesFromMapping(const mapping::OffsetTable<ArrayDims, RecordDim, SubMappings>& mapping)
             -> std::vector<FieldBox<ArrayDims::rank>>
         {
             std::size_t previousBlobs = 0;
diff --git a/include/llama/mapping/OffsetTable.hpp b/include/llama/mapping/OffsetTable.hpp
index 3f8bb894a2..04151cc132 100644
--- a/include/llama/mapping/OffsetTable.hpp
+++ b/include/llama/mapping/OffsetTable.hpp
@@ -138,16 +138,55 @@ namespace llama::mapping
         };
     } // namespace internal
 
-    template <typename T_ArrayDims, typename T_RecordDim>
+    /// A type list containing mappings.
+    template <template <typename, typename> typename... SubMappings>
+    struct MappingList;
+
+    namespace internal
+    {
+        template <typename SubRecordDims, typename Mappings>
+        struct MapSubRecordDims;
+
+        template <typename... SubRecordDims, template <typename, typename> typename... SubMappings>
+        struct MapSubRecordDims<boost::mp11::mp_list<SubRecordDims...>, MappingList<SubMappings...>>
+        {
+            static_assert(
+                sizeof...(SubRecordDims) == sizeof...(SubMappings),
+                "There must be as many mappings as sub record dimensions");
+            using List = boost::mp11::mp_list<SubMappings<ArrayDims<1>, SubRecordDims>...>;
+        };
+
+        template <typename... SubRecordDims, template <typename, typename> typename Mapping>
+        struct MapSubRecordDims<boost::mp11::mp_list<SubRecordDims...>, MappingList<Mapping>>
+        {
+        private:
+            template <typename SubRecordDim>
+            using MapRecordDim = Mapping<ArrayDims<1>, SubRecordDim>;
+
+        public:
+            using List = boost::mp11::mp_transform<MapRecordDim, boost::mp11::mp_list<SubRecordDims...>>;
+        };
+    } // namespace internal
+
+    /// Meta mapping splitting off sub branches of the given record dimension tree at each field which's type is a
+    /// dynamic array. Each dynamic array field is then replaced by an integral offset of type \ref EndOffsetType. This
+    /// offset is used to navigate from a virtual record into a dynamic sub array member using a dynamic index. Two
+    /// computed fields are added per dynamic array field, which are named \ref EndOffset and \ref Size, giving access
+    /// to the offset value and the size of a dynamic sub array. The list of sub record dimensions is then further
+    /// mapped using a list of sub mappings.
+    ///
+    /// @tparam T_RecordDim A record dimension, possibly including field types which are dynamic arrays.
+    /// @tparam SubMappings A \ref MappingList of mappings that will be used to map the sub record dimensions after
+    /// splitting T_RecordDim at each dynamic array field. If the mapping list contains a single mapping, this one will
+    /// be used to map all sub record dimensions. Otherwise, a mapping needs to be given for each sub record dimension.
+    template <typename T_ArrayDims, typename T_RecordDim, typename SubMappings = MappingList<PreconfiguredAoS<>::type>>
     struct OffsetTable
     {
         using RDS = internal::ReplaceDynamicSubarrays<T_RecordDim, RecordCoord<>>;
         using SubRecordDims = boost::mp11::mp_push_front<typename RDS::SubRecordDims, typename RDS::Replaced>;
         using SplitCoords = typename RDS::SplitCoords;
 
-        template <typename SubRecordDim>
-        using MapRecordDim = AlignedAoS<llama::ArrayDims<1>, SubRecordDim>; // TODO: make this configureable
-        using MappedSubRecordDims = boost::mp11::mp_transform<MapRecordDim, SubRecordDims>;
+        using MappedSubRecordDims = typename internal::MapSubRecordDims<SubRecordDims, SubMappings>::List;
 
         boost::mp11::mp_rename<MappedSubRecordDims, Tuple> subMappings;
 
diff --git a/tests/recorddimension.cpp b/tests/recorddimension.cpp
index c276978dcc..cd4543acff 100644
--- a/tests/recorddimension.cpp
+++ b/tests/recorddimension.cpp
@@ -340,8 +340,6 @@ TEST_CASE("edm")
         llama::ArrayDims{3},
         llama::ArrayDims{5},
         llama::ArrayDims{4}};
-    std::ofstream{"dump.edm.svg"} << llama::toSvg(mapping);
-    std::ofstream{"dump.edm.html"} << llama::toHtml(mapping);
     auto view = llama::allocView(mapping);
 
     // setup offset table
@@ -426,3 +424,60 @@ TEST_CASE("edm")
     CHECK(view(2)(Muons{})(0) (Mass{}) == value++);
     CHECK(view(2)(Muons{})(0) (Phi{}) == value++);
 }
+
+TEST_CASE("dump.edm.AlignedAoS")
+{
+    auto mapping = llama::mapping::OffsetTable<llama::ArrayDims<1>, Event>{
+        llama::ArrayDims{30},
+        llama::ArrayDims{50},
+        llama::ArrayDims{40}};
+    std::ofstream{"dump.edm.AlignedAoS.svg"} << llama::toSvg(mapping);
+    std::ofstream{"dump.edm.AlignedAoS.html"} << llama::toHtml(mapping);
+}
+
+TEST_CASE("dump.edm.MultiBlobSoA")
+{
+    auto mapping = llama::mapping::
+        OffsetTable<llama::ArrayDims<1>, Event, llama::mapping::MappingList<llama::mapping::PreconfiguredSoA<>::type>>{
+            llama::ArrayDims{30},
+            llama::ArrayDims{50},
+            llama::ArrayDims{40}};
+    std::ofstream{"dump.edm.MultiBlobSoA.svg"} << llama::toSvg(mapping);
+    std::ofstream{"dump.edm.MultiBlobSoA.html"} << llama::toHtml(mapping);
+}
+
+TEST_CASE("dump.edm.AlignedAoS_MultiBlobSoA")
+{
+    auto mapping = llama::mapping::OffsetTable<
+        llama::ArrayDims<1>,
+        Event,
+        llama::mapping::MappingList<
+            llama::mapping::PreconfiguredAoS<>::type,
+            llama::mapping::PreconfiguredSoA<>::type,
+            llama::mapping::PreconfiguredSoA<>::type>>{
+        llama::ArrayDims{30},
+        llama::ArrayDims{50},
+        llama::ArrayDims{40}};
+    std::ofstream{"dump.edm.AlignedAoS_MultiBlobSoA.svg"} << llama::toSvg(mapping);
+    std::ofstream{"dump.edm.AlignedAoS_MultiBlobSoA.html"} << llama::toHtml(mapping);
+}
+
+TEST_CASE("dump.edm.Split_AlignedAoS_MultiBlobSoA")
+{
+    auto mapping = llama::mapping::OffsetTable<
+        llama::ArrayDims<1>,
+        Event,
+        llama::mapping::MappingList<
+            llama::mapping::PreconfiguredSplit<
+                llama::RecordCoord<2>,
+                llama::mapping::PreconfiguredAoS<>::type,
+                llama::mapping::PreconfiguredAoS<>::type,
+                true>::type,
+            llama::mapping::PreconfiguredSoA<>::type,
+            llama::mapping::PreconfiguredSoA<>::type>>{
+        llama::ArrayDims{30},
+        llama::ArrayDims{50},
+        llama::ArrayDims{40}};
+    std::ofstream{"dump.edm.Split_AlignedAoS_MultiBlobSoA.svg"} << llama::toSvg(mapping);
+    std::ofstream{"dump.edm.Split_AlignedAoS_MultiBlobSoA.html"} << llama::toHtml(mapping);
+}