From 763d1968cbb87203fc935fd67a5e384ab4dde863 Mon Sep 17 00:00:00 2001
From: Felice <felice.pantaleo@cern.ch>
Date: Thu, 16 Jul 2020 16:32:16 +0200
Subject: [PATCH 1/3] Shrinking internal data structures after clearing them.

---
 .../interface/HGCalImagingAlgo.h              |  3 +++
 .../HGCalRecProducers/plugins/HGCalCLUEAlgo.h | 22 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/RecoLocalCalo/HGCalRecProducers/interface/HGCalImagingAlgo.h b/RecoLocalCalo/HGCalRecProducers/interface/HGCalImagingAlgo.h
index 6d7e2dd900265..ba072a85de7fd 100644
--- a/RecoLocalCalo/HGCalRecProducers/interface/HGCalImagingAlgo.h
+++ b/RecoLocalCalo/HGCalRecProducers/interface/HGCalImagingAlgo.h
@@ -65,9 +65,12 @@ class HGCalImagingAlgo : public HGCalClusteringAlgoBase {
   // use this if you want to reuse the same cluster object but don't want to accumulate clusters (hardly useful?)
   void reset() override {
     clusters_v_.clear();
+    clusters_v_.shrink_to_fit();
     layerClustersPerLayer_.clear();
+    layerClustersPerLayer_.shrink_to_fit();
     for (auto &it : points_) {
       it.clear();
+      it.shrink_to_fit();
       std::vector<KDNode>().swap(it);
     }
     for (unsigned int i = 0; i < minpos_.size(); i++) {
diff --git a/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h b/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h
index caf5faee1e374..861447e874b0c 100644
--- a/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h
+++ b/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h
@@ -63,12 +63,15 @@ class HGCalCLUEAlgoT : public HGCalClusteringAlgoBase {
 
   void reset() override {
     clusters_v_.clear();
+    clusters_v_.shrink_to_fit();
     for (auto& cl : numberOfClustersPerLayer_) {
       cl = 0;
     }
 
-    for (auto& cells : cells_)
+    for (auto& cells : cells_) {
       cells.clear();
+      cells.shrink_to_fit();
+    }
   }
 
   Density getDensity() override;
@@ -174,6 +177,23 @@ class HGCalCLUEAlgoT : public HGCalClusteringAlgoBase {
       followers.clear();
       isSeed.clear();
     }
+
+    void shrink_to_fit() {
+      detid.shrink_to_fit();
+      isSi.shrink_to_fit();
+      x.shrink_to_fit();
+      y.shrink_to_fit();
+      eta.shrink_to_fit();
+      phi.shrink_to_fit();
+      weight.shrink_to_fit();
+      rho.shrink_to_fit();
+      delta.shrink_to_fit();
+      nearestHigher.shrink_to_fit();
+      clusterIndex.shrink_to_fit();
+      sigmaNoise.shrink_to_fit();
+      followers.shrink_to_fit();
+      isSeed.shrink_to_fit();
+    }
   };
 
   std::vector<CellsOnLayer> cells_;

From 59d5d8f4e32e48a45dfa6397adcd8fe5b2dc167f Mon Sep 17 00:00:00 2001
From: Felice <felice.pantaleo@cern.ch>
Date: Fri, 17 Jul 2020 14:59:55 +0200
Subject: [PATCH 2/3] Clearing density map

---
 RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h b/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h
index 861447e874b0c..bfca51b3c0384 100644
--- a/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h
+++ b/RecoLocalCalo/HGCalRecProducers/plugins/HGCalCLUEAlgo.h
@@ -72,6 +72,7 @@ class HGCalCLUEAlgoT : public HGCalClusteringAlgoBase {
       cells.clear();
       cells.shrink_to_fit();
     }
+    density_.clear();
   }
 
   Density getDensity() override;

From 0845af314dd0fab48af3247c3a426031b63d515a Mon Sep 17 00:00:00 2001
From: Felice <felice.pantaleo@cern.ch>
Date: Fri, 17 Jul 2020 15:00:51 +0200
Subject: [PATCH 3/3] Reset at the end of produce

---
 .../HGCalRecProducers/plugins/HGCalLayerClusterProducer.cc     | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/RecoLocalCalo/HGCalRecProducers/plugins/HGCalLayerClusterProducer.cc b/RecoLocalCalo/HGCalRecProducers/plugins/HGCalLayerClusterProducer.cc
index bc5c7d90692b2..fba15664ae202 100644
--- a/RecoLocalCalo/HGCalRecProducers/plugins/HGCalLayerClusterProducer.cc
+++ b/RecoLocalCalo/HGCalRecProducers/plugins/HGCalLayerClusterProducer.cc
@@ -133,8 +133,6 @@ void HGCalLayerClusterProducer::produce(edm::Event& evt, const edm::EventSetup&
       clusters_sharing(new std::vector<reco::BasicCluster>);
   auto density = std::make_unique<Density>();
 
-  algo->reset();
-
   algo->getEventSetup(es);
 
   //make a map detid-rechit
@@ -246,6 +244,7 @@ void HGCalLayerClusterProducer::produce(edm::Event& evt, const edm::EventSetup&
       clusterPtrsSharing.push_back(ptr);
     }
   }
+  algo->reset();
 }
 
 #endif