From bddd18fd9bba7cda4e1dc325185456bdf04dba9e Mon Sep 17 00:00:00 2001
From: Christopher Jones <chrisdjones15@gmail.com>
Date: Wed, 19 Nov 2025 15:10:55 -0600
Subject: [PATCH] Avoid ROOT auto parsing for PortableHostMultiCollection

Memory increases when moving to ROOT 6.36 pointed to these
 two classes not having dictionaries explicitly defined.
---
 DataFormats/TrackingRecHitSoA/src/classes_def.xml | 3 +++
 DataFormats/VertexSoA/src/classes_def.xml         | 4 +++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/DataFormats/TrackingRecHitSoA/src/classes_def.xml b/DataFormats/TrackingRecHitSoA/src/classes_def.xml
index 03af69a6217c1..3384a6e226543 100644
--- a/DataFormats/TrackingRecHitSoA/src/classes_def.xml
+++ b/DataFormats/TrackingRecHitSoA/src/classes_def.xml
@@ -4,6 +4,9 @@
   <class name="reco::HitModulesLayout<128, false>"/>
 
   <class name="reco::HitPortableCollectionHost"/>
+  <!-- needed to avoid auto parsing by ROOT. Order in the file matters -->
+  <class name="reco::HitPortableCollectionHost::Implementation"/>
+
   <class name="reco::TrackingRecHitHost"  rntupleStreamerMode="true"/>
   <class name="edm::Wrapper<reco::TrackingRecHitHost>" splitLevel="0"/>
 
diff --git a/DataFormats/VertexSoA/src/classes_def.xml b/DataFormats/VertexSoA/src/classes_def.xml
index 978abdff8075f..1f924cb466f4a 100644
--- a/DataFormats/VertexSoA/src/classes_def.xml
+++ b/DataFormats/VertexSoA/src/classes_def.xml
@@ -3,7 +3,9 @@
   <!-- FIXME using the ZVertexSoA and ZVertexTracksSoA type aliases here and below does not work -->
   <class name="reco::ZVertexLayout<128, false>"/>
   <class name="reco::ZVertexTracksLayout<128, false>"/>
-
+  <!-- needed to avoid auto parsing by ROOT. Order in the file matters -->
+  <class name="ZVertexHost::Implementation"/>
+  
   <!-- Recursive templates (with no data) ensuring we have one CollectionLeaf<index, type> for each layout in the collection -->
   <class name="portablecollection::CollectionImpl<0, reco::ZVertexLayout<128, false>, reco::ZVertexTracksLayout<128, false>>"/>
   <class name="portablecollection::CollectionImpl<1, reco::ZVertexTracksLayout<128, false>>"/>