Case-insensitive index access

* fix the Binding node always using #_Table_ instead of _Label_ for
  custom index colums
* use case-insensitive comparison for looking up index columns in
  soa::Table and arrow::Table, as the custom-declared index columns
  may have inconsistent capitalization in their names

Author: aalkin

Framework/Core/include/Framework/ASoA.h

@@ -1376,7 +1376,15 @@ static constexpr std::string getLabelFromType()
 template <typename... C>
 static constexpr auto hasColumnForKey(framework::pack<C...>, std::string const& key)
 {
-  return ((C::inherited_t::mLabel == key) || ...);
+  auto caseInsensitiveCompare = [](const std::string_view& str1, const std::string& str2) {
+    return std::ranges::equal(
+      str1, str2,
+      [](char c1, char c2) {
+        return std::tolower(static_cast<unsigned char>(c1)) ==
+               std::tolower(static_cast<unsigned char>(c2));
+      });
+  };
+  return (caseInsensitiveCompare(C::inherited_t::mLabel, key) || ...);
 }
 
 template <TableRef ref>
@@ -2866,7 +2874,7 @@ consteval auto getIndexTargets()
     o2::soa::Binding getCurrentRaw() const { return mBinding; }                                                                 \
     o2::soa::Binding mBinding;                                                                                                  \
   };                                                                                                                            \
-  [[maybe_unused]] static constexpr o2::framework::expressions::BindingNode _Getter_##Id { "fIndex" #_Table_ _Suffix_, _Name_##Id::hash, o2::framework::expressions::selectArrowType<_Type_>() }
+  [[maybe_unused]] static constexpr o2::framework::expressions::BindingNode _Getter_##Id { "fIndex" _Label_ _Suffix_, _Name_##Id::hash, o2::framework::expressions::selectArrowType<_Type_>() }
 
 #define DECLARE_SOA_INDEX_COLUMN_FULL(_Name_, _Getter_, _Type_, _Table_, _Suffix_) DECLARE_SOA_INDEX_COLUMN_FULL_CUSTOM(_Name_, _Getter_, _Type_, _Table_, #_Table_, _Suffix_)
 #define DECLARE_SOA_INDEX_COLUMN(_Name_, _Getter_) DECLARE_SOA_INDEX_COLUMN_FULL(_Name_, _Getter_, int32_t, _Name_##s, "")

Framework/Core/src/ArrowTableSlicingCache.cxx

@@ -19,6 +19,24 @@
 namespace o2::framework
 {
 
+namespace {
+std::shared_ptr<arrow::ChunkedArray> GetColumnByNameCI(std::shared_ptr<arrow::Table> const& table, std::string const& key)
+{
+  auto const& fields = table->schema()->fields();
+  auto target = std::find_if(fields.begin(), fields.end(), [&key](std::shared_ptr<arrow::Field> const& field){
+    return [](std::string_view const& s1, std::string_view const& s2){
+      return std::ranges::equal(
+        s1, s2,
+        [](char c1, char c2){
+          return std::tolower(static_cast<unsigned char>(c1)) == std::tolower(static_cast<unsigned char>(c2));
+        }
+        );
+    }(field->name(), key);
+  });
+  return table->column(std::distance(fields.begin(), target));
+}
+}
+
 void updatePairList(Cache& list, std::string const& binding, std::string const& key, bool enabled = true)
 {
   auto locate = std::find_if(list.begin(), list.end(), [&binding, &key](auto const& entry) { return (entry.binding == binding) && (entry.key == key); });
@@ -99,7 +117,7 @@ arrow::Status ArrowTableSlicingCache::updateCacheEntry(int pos, std::shared_ptr<
   validateOrder(bindingsKeys[pos], table);
 
   int maxValue = -1;
-  auto column = table->GetColumnByName(k);
+  auto column = GetColumnByNameCI(table, k);
 
   // starting from the end, find the first positive value, in a sorted column it is the largest index
   for (auto iChunk = column->num_chunks() - 1; iChunk >= 0; --iChunk) {
@@ -155,7 +173,7 @@ arrow::Status ArrowTableSlicingCache::updateCacheEntryUnsorted(int pos, const st
   if (!e) {
     throw runtime_error_f("Disabled unsorted cache %s/%s update requested", b.c_str(), k.c_str());
   }
-  auto column = table->GetColumnByName(k);
+  auto column = GetColumnByNameCI(table, k);
   auto row = 0;
   for (auto iChunk = 0; iChunk < column->num_chunks(); ++iChunk) {
     auto chunk = static_cast<arrow::NumericArray<arrow::Int32Type>>(column->chunk(iChunk)->data());
@@ -252,7 +270,7 @@ SliceInfoUnsortedPtr ArrowTableSlicingCache::getCacheUnsortedForPos(int pos) con
 void ArrowTableSlicingCache::validateOrder(Entry const& bindingKey, const std::shared_ptr<arrow::Table>& input)
 {
   auto const& [target, key, enabled] = bindingKey;
-  auto column = input->GetColumnByName(key);
+  auto column = o2::framework::GetColumnByNameCI(input, key);
   auto array0 = static_cast<arrow::NumericArray<arrow::Int32Type>>(column->chunk(0)->data());
   int32_t prev = 0;
   int32_t cur = array0.Value(0);