From 52f801b77ebdf1b927451fed1e640331366e029a Mon Sep 17 00:00:00 2001
From: Giulio Eulisse <10544+ktf@users.noreply.github.com>
Date: Wed, 22 Jan 2025 13:09:26 +0100
Subject: [PATCH] DPL: improve getIndexFromLabel

Avoids extra string creation.
---
 Framework/Core/include/Framework/ASoA.h |  2 +-
 Framework/Core/src/ASoA.cxx             | 13 +++++++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/Framework/Core/include/Framework/ASoA.h b/Framework/Core/include/Framework/ASoA.h
index 7b0b69ec8941f..0a5092bbd0959 100644
--- a/Framework/Core/include/Framework/ASoA.h
+++ b/Framework/Core/include/Framework/ASoA.h
@@ -1619,7 +1619,7 @@ auto select(T const& t, framework::expressions::Filter const& f)
   return Filtered<T>({t.asArrowTable()}, selectionToVector(framework::expressions::createSelection(t.asArrowTable(), f)));
 }
 
-arrow::ChunkedArray* getIndexFromLabel(arrow::Table* table, const char* label);
+arrow::ChunkedArray* getIndexFromLabel(arrow::Table* table, std::string_view label);
 
 template <typename D, typename O, typename IP, typename... C>
 consteval auto base_iter(framework::pack<C...>&&) -> TableIterator<D, O, IP, C...>
diff --git a/Framework/Core/src/ASoA.cxx b/Framework/Core/src/ASoA.cxx
index 38a6750a90dbe..a37d0f33891e7 100644
--- a/Framework/Core/src/ASoA.cxx
+++ b/Framework/Core/src/ASoA.cxx
@@ -123,10 +123,19 @@ std::shared_ptr<arrow::Table> ArrowHelpers::concatTables(std::vector<std::shared
   return result;
 }
 
-arrow::ChunkedArray* getIndexFromLabel(arrow::Table* table, const char* label)
+arrow::ChunkedArray* getIndexFromLabel(arrow::Table* table, std::string_view label)
 {
   auto field = std::find_if(table->schema()->fields().begin(), table->schema()->fields().end(), [&](std::shared_ptr<arrow::Field> const& f) {
-    return o2::framework::strToUpper(label) == o2::framework::strToUpper(std::string{f->name()});
+    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(label, f->name());
   });
   if (field == table->schema()->fields().end()) {
     o2::framework::throw_error(o2::framework::runtime_error_f("Unable to find column with label %s", label));