From 1a6b31d2f0e0ca74038373908614112f6170221e Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 26 Jun 2024 11:25:03 +0200
Subject: [PATCH 01/25] [QC-885] Modify ReferenceComparatorCheck to also accept
 a TH1 instead of a Canvas

- also pass the database object from CheckRunner to CheckInterface and use it to implement a new method `retrieveReference`.
---
 Framework/include/QualityControl/Check.h      |  6 ++
 .../include/QualityControl/CheckInterface.h   | 12 +++
 .../include/QualityControl/ReferenceUtils.h   | 61 +++++++++++++++
 .../include/QualityControl/RepoPathUtils.h    | 13 ++++
 Framework/src/CheckInterface.cxx              |  6 ++
 Framework/src/CheckRunner.cxx                 |  1 +
 .../include/Common/ReferenceComparatorCheck.h |  3 +
 .../include/Common/ReferenceComparatorTask.h  |  4 -
 .../Common/src/ReferenceComparatorCheck.cxx   | 75 ++++++++++++++-----
 .../Common/src/ReferenceComparatorTask.cxx    | 59 +--------------
 doc/Advanced.md                               |  6 ++
 11 files changed, 166 insertions(+), 80 deletions(-)
 create mode 100644 Framework/include/QualityControl/ReferenceUtils.h

diff --git a/Framework/include/QualityControl/Check.h b/Framework/include/QualityControl/Check.h
index 879808b2cb..a1376e94fc 100644
--- a/Framework/include/QualityControl/Check.h
+++ b/Framework/include/QualityControl/Check.h
@@ -19,8 +19,10 @@
 // O2
 #include <Framework/DataProcessorSpec.h>
 // QC
+#include "QualityControl/DatabaseInterface.h"
 #include "QualityControl/QualityObject.h"
 #include "QualityControl/CheckConfig.h"
+#include "QualityControl/CheckInterface.h"
 
 namespace o2::quality_control::core
 {
@@ -92,6 +94,10 @@ class Check
   static CheckConfig extractConfig(const core::CommonSpec&, const CheckSpec&);
   static framework::OutputSpec createOutputSpec(const std::string& detector, const std::string& checkName);
 
+  void setDatabase(std::shared_ptr<o2::quality_control::repository::DatabaseInterface> database) {
+    mCheckInterface->setDatabase(database);
+  }
+
  private:
   void beautify(std::map<std::string, std::shared_ptr<core::MonitorObject>>& moMap, const core::Quality& quality);
 
diff --git a/Framework/include/QualityControl/CheckInterface.h b/Framework/include/QualityControl/CheckInterface.h
index efe63cf29b..e3f8a47657 100644
--- a/Framework/include/QualityControl/CheckInterface.h
+++ b/Framework/include/QualityControl/CheckInterface.h
@@ -17,6 +17,7 @@
 #ifndef QC_CHECKER_CHECKINTERFACE_H
 #define QC_CHECKER_CHECKINTERFACE_H
 
+#include "QualityControl/DatabaseInterface.h"
 #include "QualityControl/Quality.h"
 #include "QualityControl/UserCodeInterface.h"
 #include "QualityControl/Activity.h"
@@ -82,10 +83,21 @@ class CheckInterface : public core::UserCodeInterface
   virtual void startOfActivity(const core::Activity& activity); // not fully abstract because we don't want to change all the existing subclasses
   virtual void endOfActivity(const core::Activity& activity);   // not fully abstract because we don't want to change all the existing subclasses
 
+  void setDatabase(std::shared_ptr<o2::quality_control::repository::DatabaseInterface> database) {
+    mDatabase = database;
+  }
+
  protected:
   /// \brief Called each time mCustomParameters is updated.
   virtual void configure() override;
 
+  /// \brief Retrieve a reference plot at the provided path, matching the give activity and for the provided run.
+  /// the activity is the current one, while the run number is the reference run.
+  std::shared_ptr<MonitorObject> retrieveReference(std::string path, int referenceRun, Activity activity);
+
+ private:
+  std::shared_ptr<o2::quality_control::repository::DatabaseInterface> mDatabase;
+
   ClassDef(CheckInterface, 6)
 };
 
diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
new file mode 100644
index 0000000000..304d8edcde
--- /dev/null
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -0,0 +1,61 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+///
+/// \file   ReferenceComparatorUtils.h
+/// \author Andrea Ferrero and Barthelemy von Haller
+///
+
+#ifndef QUALITYCONTROL_ReferenceComparatorUtils_H
+#define QUALITYCONTROL_ReferenceComparatorUtils_H
+
+#include <memory>
+#include "QualityControl/MonitorObject.h"
+#include "QualityControl/DatabaseInterface.h"
+#include "QualityControl/Activity.h"
+#include "QualityControl/ActivityHelpers.h"
+#include "QualityControl/QcInfoLogger.h"
+#include "QualityControl/RepoPathUtils.h"
+
+namespace o2::quality_control_modules::common
+{
+
+//_________________________________________________________________________________________
+//
+// Get the reference plot for a given MonitorObject path
+
+static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath, uint32_t referenceRun, quality_control::core::Activity activity)
+{
+  uint64_t timeStamp = 0;
+  activity.mId = referenceRun;
+  const auto filterMetadata = quality_control::core::activity_helpers::asDatabaseMetadata(activity, false);
+  const auto objectValidity = qcdb->getLatestObjectValidity(activity.mProvenance + "/" + fullPath, filterMetadata);
+  if (objectValidity.isValid()) {
+    timeStamp = objectValidity.getMax() - 1;
+  } else {
+    ILOG(Warning, Devel) << "Could not find the object '" << fullPath << "' for run " << activity.mId << ENDM;
+    return nullptr;
+  }
+
+  std::string path;
+  std::string name;
+  if (!o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath, path, name)) {
+    return nullptr;
+  }
+  // retrieve MO from CCDB
+  auto mo = qcdb->retrieveMO(path, name, timeStamp, activity);
+
+  return mo;
+}
+
+} // namespace o2::quality_control_modules::common
+
+#endif // QUALITYCONTROL_ReferenceComparatorUtils_H
diff --git a/Framework/include/QualityControl/RepoPathUtils.h b/Framework/include/QualityControl/RepoPathUtils.h
index ac03cfeeb8..af3a627577 100644
--- a/Framework/include/QualityControl/RepoPathUtils.h
+++ b/Framework/include/QualityControl/RepoPathUtils.h
@@ -128,6 +128,19 @@ class RepoPathUtils
 
   static constexpr auto allowedProvenancesMessage = R"(Allowed provenances are "qc" (real data processed synchronously), "qc_async" (real data processed asynchronously) and "qc_mc" (simulated data).)";
   static bool isProvenanceAllowed(const std::string& provenance);
+
+  static bool splitObjectPath(const std::string& fullPath, std::string& path, std::string& name)
+  {
+    std::string delimiter = "/";
+    std::string det;
+    size_t pos = fullPath.rfind(delimiter);
+    if (pos == std::string::npos) {
+      return false;
+    }
+    path = fullPath.substr(0, pos);
+    name = fullPath.substr(pos + 1);
+    return true;
+  }
 };
 } // namespace o2::quality_control::core
 
diff --git a/Framework/src/CheckInterface.cxx b/Framework/src/CheckInterface.cxx
index 6d07cb3cda..bdc7c0cf5f 100644
--- a/Framework/src/CheckInterface.cxx
+++ b/Framework/src/CheckInterface.cxx
@@ -15,6 +15,7 @@
 ///
 
 #include "QualityControl/CheckInterface.h"
+#include "QualityControl/ReferenceUtils.h"
 #include "QualityControl/MonitorObject.h"
 
 #include <TClass.h>
@@ -59,4 +60,9 @@ void CheckInterface::endOfActivity(const Activity& activity)
   // noop, override it if you want.
 }
 
+shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, int referenceRun, Activity activity)
+{
+  return quality_control_modules::common::getReferencePlot(mDatabase.get(), path, referenceRun, activity);
+}
+
 } // namespace o2::quality_control::checker
diff --git a/Framework/src/CheckRunner.cxx b/Framework/src/CheckRunner.cxx
index 62cad609c5..e231e9131e 100644
--- a/Framework/src/CheckRunner.cxx
+++ b/Framework/src/CheckRunner.cxx
@@ -231,6 +231,7 @@ void CheckRunner::init(framework::InitContext& iCtx)
     updatePolicyManager.reset();
     for (auto& [checkName, check] : mChecks) {
       check.init();
+      check.setDatabase(mDatabase);
       updatePolicyManager.addPolicy(check.getName(), check.getUpdatePolicyType(), check.getObjectsNames(), check.getAllObjectsOption(), false);
     }
   } catch (...) {
diff --git a/Modules/Common/include/Common/ReferenceComparatorCheck.h b/Modules/Common/include/Common/ReferenceComparatorCheck.h
index 1f7f070b25..200a358d1d 100644
--- a/Modules/Common/include/Common/ReferenceComparatorCheck.h
+++ b/Modules/Common/include/Common/ReferenceComparatorCheck.h
@@ -49,9 +49,12 @@ class ReferenceComparatorCheck : public o2::quality_control::checker::CheckInter
   void endOfActivity(const Activity& activity) override;
 
  private:
+  Quality getSinglePlotQuality(std::shared_ptr<MonitorObject> mo, std::string& message);
+
   std::unique_ptr<ObjectComparatorInterface> mComparator;
   std::map<std::string, Quality> mQualityFlags;
   std::map<std::string, std::shared_ptr<TPaveText>> mQualityLabels;
+  quality_control::core::Activity mActivity;
 };
 
 } // namespace o2::quality_control_modules::common
diff --git a/Modules/Common/include/Common/ReferenceComparatorTask.h b/Modules/Common/include/Common/ReferenceComparatorTask.h
index 195f9f27a5..57f582c458 100644
--- a/Modules/Common/include/Common/ReferenceComparatorTask.h
+++ b/Modules/Common/include/Common/ReferenceComparatorTask.h
@@ -19,10 +19,8 @@
 #define QUALITYCONTROL_REFERENCECOMPARATORTASK_H
 
 #include "Common/ReferenceComparatorTaskConfig.h"
-#include "Common/BigScreenCanvas.h"
 #include "QualityControl/PostProcessingInterface.h"
 #include "QualityControl/DatabaseInterface.h"
-#include "QualityControl/Quality.h"
 #include <TH1.h>
 #include <TPad.h>
 #include <TCanvas.h>
@@ -63,8 +61,6 @@ class ReferenceComparatorTask : public quality_control::postprocessing::PostProc
   };
 
  private:
-  std::shared_ptr<o2::quality_control::core::MonitorObject> getReferencePlot(o2::quality_control::repository::DatabaseInterface& qcdb, std::string fullPath, o2::quality_control::core::Activity activity);
-
   int mReferenceRun{ 0 };
   int mNotOlderThan{ 120 };
 
diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index bde10cf1a3..60c2388a37 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -15,8 +15,8 @@
 ///
 
 #include "Common/ReferenceComparatorCheck.h"
+#include "QualityControl/ReferenceUtils.h"
 #include "Common/TH1Ratio.h"
-#include "Common/TH2Ratio.h"
 #include "QualityControl/MonitorObject.h"
 #include "QualityControl/Quality.h"
 #include "QualityControl/QcInfoLogger.h"
@@ -25,6 +25,8 @@
 #include <DataFormatsQualityControl/FlagType.h>
 #include <DataFormatsQualityControl/FlagTypeFactory.h>
 
+#include <Framework/ServiceRegistryRef.h>
+
 // ROOT
 #include <TH1.h>
 #include <TCanvas.h>
@@ -54,6 +56,8 @@ void ReferenceComparatorCheck::startOfActivity(const Activity& activity)
   if (mComparator) {
     mComparator->setThreshold(threshold);
   }
+
+  mActivity = activity;
 }
 
 void ReferenceComparatorCheck::endOfActivity(const Activity& activity)
@@ -129,6 +133,33 @@ static Quality compare(TCanvas* canvas, ObjectComparatorInterface* comparator, s
   return comparator->compare(plots.first, plots.second, message);
 }
 
+
+Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorObject> mo, std::string& message)
+{
+  // retrieve the reference plot and compare
+  auto* th1 = dynamic_cast<TH1*>(mo->getObject());
+  auto referenceRun = std::stoi(mCustomParameters.atOptional("referenceRun").value_or("0"));
+
+  // get path of mo and ref (we have to remove the provenance)
+  string path = mo->getPath();
+  size_t pos = path.find('/');
+  if (pos != std::string::npos) {
+    path = path.substr(pos + 1);
+  }
+
+  auto referencePlot = retrieveReference(path, referenceRun, mActivity);
+  if (!referencePlot) {
+    ILOG(Warning, Ops) << "The reference plot is empty" << ENDM;
+    return Quality::Null;
+  }
+  auto* ref = dynamic_cast<TH1*>(referencePlot->getObject());
+  if (!ref) {
+    ILOG(Warning, Ops) << "The reference plot is not a TH1" << ENDM;
+    return Quality::Null;
+  }
+  return mComparator.get()->compare(th1, ref, message);
+}
+
 //_________________________________________________________________________________________
 //
 // Loop over all the input MOs and compare each of them with the corresponding MO from the reference run
@@ -139,17 +170,22 @@ Quality ReferenceComparatorCheck::check(std::map<std::string, std::shared_ptr<Mo
   Quality result = Quality::Good;
   for (auto& [key, mo] : *moMap) {
     auto moName = mo->getName();
+    Quality quality;
+    std::string message;
 
-    auto* canvas = dynamic_cast<TCanvas*>(mo->getObject());
-    if (!canvas) {
+    // run the comparison algorithm
+    if (mo->getObject()->IsA() == TClass::GetClass<TCanvas>()) {
+      // We got a canvas. It contains the plot and its reference.
+      auto* canvas = dynamic_cast<TCanvas*>(mo->getObject());
+      quality = compare(canvas, mComparator.get(), message);
+    } else if (mo->getObject()->InheritsFrom(TH1::Class())) {
+      // We got a plot, we have to find the reference before calling the comparator
+      quality = getSinglePlotQuality(mo, message);
+    } else {
+      ILOG(Warning, Ops) << "mo is not a TCanvas or a TH1" << ENDM;
       continue;
     }
 
-    // run the comparison algorithm
-    Quality quality;
-    std::string message;
-    quality = compare(canvas, mComparator.get(), message);
-
     // update the overall quality
     if (quality.isWorseThan(result)) {
       result.set(quality);
@@ -229,23 +265,22 @@ static void setQualityLabel(TCanvas* canvas, const Quality& quality)
 
 void ReferenceComparatorCheck::beautify(std::shared_ptr<MonitorObject> mo, Quality checkResult)
 {
-  auto* canvas = dynamic_cast<TCanvas*>(mo->getObject());
-  if (!canvas) {
-    return;
-  }
-
   // get the quality associated to the current MO
   auto moName = mo->getName();
   auto quality = mQualityFlags[moName];
 
-  // retrieve the reference plot from the canvas and set the line color according to the quality
-  auto plots = getPlotsFromCanvas(canvas);
-  if (plots.second) {
-    plots.second->SetLineColor(getQualityColor(quality));
-  }
+  auto* canvas = dynamic_cast<TCanvas*>(mo->getObject());
+  if (canvas) {
+    // retrieve the reference plot from the canvas and set the line color according to the quality
+    auto plots = getPlotsFromCanvas(canvas);
+    if (plots.second) {
+      plots.second->SetLineColor(getQualityColor(quality));
+    }
 
-  // draw the quality label on the plot
-  setQualityLabel(canvas, quality);
+    // draw the quality label on the plot
+    setQualityLabel(canvas, quality);
+  }
+  // TODO handle the case of simple MO
 }
 
 } // namespace o2::quality_control_modules::common
diff --git a/Modules/Common/src/ReferenceComparatorTask.cxx b/Modules/Common/src/ReferenceComparatorTask.cxx
index 0e21d2866c..0e937e9b84 100644
--- a/Modules/Common/src/ReferenceComparatorTask.cxx
+++ b/Modules/Common/src/ReferenceComparatorTask.cxx
@@ -17,8 +17,7 @@
 
 #include "Common/ReferenceComparatorTask.h"
 #include "Common/ReferenceComparatorPlot.h"
-#include "Common/TH1Ratio.h"
-#include "Common/TH2Ratio.h"
+#include "QualityControl/ReferenceUtils.h"
 #include "QualityControl/QcInfoLogger.h"
 #include "QualityControl/MonitorObject.h"
 #include "QualityControl/DatabaseInterface.h"
@@ -26,8 +25,6 @@
 // ROOT
 #include <TClass.h>
 #include <TH1.h>
-#include <TH2.h>
-#include <TCanvas.h>
 
 using namespace o2::quality_control::postprocessing;
 using namespace o2::quality_control::core;
@@ -36,47 +33,6 @@ using namespace o2::quality_control;
 namespace o2::quality_control_modules::common
 {
 
-static bool splitObjectPath(const std::string& fullPath, std::string& path, std::string& name)
-{
-  std::string delimiter = "/";
-  std::string det;
-  size_t pos = fullPath.rfind(delimiter);
-  if (pos == std::string::npos) {
-    return false;
-  }
-  path = fullPath.substr(0, pos);
-  name = fullPath.substr(pos + 1);
-  return true;
-}
-
-//_________________________________________________________________________________________
-//
-// Helper function for retrieving the last MonitorObject for a give run number
-
-static std::shared_ptr<MonitorObject> getMOFromRun(repository::DatabaseInterface* qcdb, const std::string& fullPath, uint32_t run, Activity activity)
-{
-  uint64_t timeStamp = 0;
-  activity.mId = run;
-  const auto filterMetadata = activity_helpers::asDatabaseMetadata(activity, false);
-  const auto objectValidity = qcdb->getLatestObjectValidity(activity.mProvenance + "/" + fullPath, filterMetadata);
-  if (objectValidity.isValid()) {
-    timeStamp = objectValidity.getMax() - 1;
-  } else {
-    ILOG(Warning, Devel) << "Could not find the object '" << fullPath << "' for run " << activity.mId << ENDM;
-    return nullptr;
-  }
-
-  std::string path;
-  std::string name;
-  if (!splitObjectPath(fullPath, path, name)) {
-    return nullptr;
-  }
-  // retrieve MO from CCDB
-  auto mo = qcdb->retrieveMO(path, name, timeStamp, activity);
-
-  return mo;
-}
-
 //_________________________________________________________________________________________
 // Helper function for retrieving a MonitorObject from the QCDB, in the form of a std::pair<std::shared_ptr<MonitorObject>, bool>
 // A non-null MO is returned in the first element of the pair if the MO is found in the QCDB
@@ -98,7 +54,7 @@ static std::pair<std::shared_ptr<MonitorObject>, bool> getMO(repository::Databas
 
   std::string path;
   std::string name;
-  if (!splitObjectPath(fullPath, path, name)) {
+  if (!o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath, path, name)) {
     return { nullptr, false };
   }
   // retrieve QO from CCDB - do not associate to trigger activity if ignoreActivity is true
@@ -117,15 +73,6 @@ static std::pair<std::shared_ptr<MonitorObject>, bool> getMO(repository::Databas
   return { qo, true };
 }
 
-//_________________________________________________________________________________________
-//
-// Get the reference plot for a given MonitorObject path
-
-std::shared_ptr<MonitorObject> ReferenceComparatorTask::getReferencePlot(repository::DatabaseInterface& qcdb, std::string fullPath, Activity activity)
-{
-  return getMOFromRun(&qcdb, fullPath, mReferenceRun, activity);
-}
-
 //_________________________________________________________________________________________
 
 void ReferenceComparatorTask::configure(const boost::property_tree::ptree& config)
@@ -156,7 +103,7 @@ void ReferenceComparatorTask::initialize(quality_control::postprocessing::Trigge
       auto fullOutPath = group.outputPath + "/" + path;
 
       // retrieve the reference MO
-      auto referencePlot = getReferencePlot(qcdb, fullRefPath, t.activity);
+      auto referencePlot = getReferencePlot(&qcdb, fullRefPath, mReferenceRun, t.activity);
       if (!referencePlot) {
         continue;
       }
diff --git a/doc/Advanced.md b/doc/Advanced.md
index c9db65140d..2d396d147a 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1308,6 +1308,12 @@ void customize(std::vector<ConfigParamSpec>& workflowOptions)
 }
 ```
 
+## Reference data
+TODO
+- PP task -> pointer
+- Checker -> if PP -> pointer
+- Checker on TH1 -> describe here
+
 ## Configuration files details
 
 The QC requires a number of configuration items. An example config file is

From 603a00c1c07c11b1e81baacb1f3a4878ecd0c8c8 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 26 Jun 2024 11:26:19 +0200
Subject: [PATCH 02/25] format

---
 Framework/include/QualityControl/Check.h          | 3 ++-
 Framework/include/QualityControl/CheckInterface.h | 3 ++-
 Modules/Common/src/ReferenceComparatorCheck.cxx   | 1 -
 doc/DevelopersTips.md                             | 4 ++++
 4 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/Framework/include/QualityControl/Check.h b/Framework/include/QualityControl/Check.h
index a1376e94fc..2d9b969c29 100644
--- a/Framework/include/QualityControl/Check.h
+++ b/Framework/include/QualityControl/Check.h
@@ -94,7 +94,8 @@ class Check
   static CheckConfig extractConfig(const core::CommonSpec&, const CheckSpec&);
   static framework::OutputSpec createOutputSpec(const std::string& detector, const std::string& checkName);
 
-  void setDatabase(std::shared_ptr<o2::quality_control::repository::DatabaseInterface> database) {
+  void setDatabase(std::shared_ptr<o2::quality_control::repository::DatabaseInterface> database)
+  {
     mCheckInterface->setDatabase(database);
   }
 
diff --git a/Framework/include/QualityControl/CheckInterface.h b/Framework/include/QualityControl/CheckInterface.h
index e3f8a47657..394d9488c9 100644
--- a/Framework/include/QualityControl/CheckInterface.h
+++ b/Framework/include/QualityControl/CheckInterface.h
@@ -83,7 +83,8 @@ class CheckInterface : public core::UserCodeInterface
   virtual void startOfActivity(const core::Activity& activity); // not fully abstract because we don't want to change all the existing subclasses
   virtual void endOfActivity(const core::Activity& activity);   // not fully abstract because we don't want to change all the existing subclasses
 
-  void setDatabase(std::shared_ptr<o2::quality_control::repository::DatabaseInterface> database) {
+  void setDatabase(std::shared_ptr<o2::quality_control::repository::DatabaseInterface> database)
+  {
     mDatabase = database;
   }
 
diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 60c2388a37..038aef6ca6 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -133,7 +133,6 @@ static Quality compare(TCanvas* canvas, ObjectComparatorInterface* comparator, s
   return comparator->compare(plots.first, plots.second, message);
 }
 
-
 Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorObject> mo, std::string& message)
 {
   // retrieve the reference plot and compare
diff --git a/doc/DevelopersTips.md b/doc/DevelopersTips.md
index 6fd8b8f4f0..9bbc281887 100644
--- a/doc/DevelopersTips.md
+++ b/doc/DevelopersTips.md
@@ -143,6 +143,10 @@ firewall-cmd --reload
 10. Set the monitoring url to `"url": "stdout://?qc,influxdb-udp://flptest1.cern.ch:8089"`
 11. Once the dashboard is ready, tell Adam.
 
+ALTERNATIVELY
+
+use http://alio2-bld4-mx-dev01-gpn:3000/?orgId=1 (admin and pwd like above)
+
 ### Monitoring setup for building the grafana dashboard with prod data
 
 1. Go to http://pcald24.cern.ch:3000/?orgId=1

From 626e7c400441cc0187832df11d89ea5d1c5e2b87 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 26 Jun 2024 12:22:01 +0200
Subject: [PATCH 03/25] add beautify and doc

---
 .../include/QualityControl/ReferenceUtils.h   |  5 +-
 .../include/Common/ReferenceComparatorTask.h  |  1 -
 doc/Advanced.md                               | 71 +++++++++++++++++--
 3 files changed, 68 insertions(+), 9 deletions(-)

diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 304d8edcde..2f096ac9b3 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -50,10 +50,7 @@ static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(qu
   if (!o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath, path, name)) {
     return nullptr;
   }
-  // retrieve MO from CCDB
-  auto mo = qcdb->retrieveMO(path, name, timeStamp, activity);
-
-  return mo;
+  return qcdb->retrieveMO(path, name, timeStamp, activity);
 }
 
 } // namespace o2::quality_control_modules::common
diff --git a/Modules/Common/include/Common/ReferenceComparatorTask.h b/Modules/Common/include/Common/ReferenceComparatorTask.h
index 57f582c458..5990f50fec 100644
--- a/Modules/Common/include/Common/ReferenceComparatorTask.h
+++ b/Modules/Common/include/Common/ReferenceComparatorTask.h
@@ -24,7 +24,6 @@
 #include <TH1.h>
 #include <TPad.h>
 #include <TCanvas.h>
-#include <TPaveText.h>
 #include <TText.h>
 #include <string>
 #include <map>
diff --git a/doc/Advanced.md b/doc/Advanced.md
index 2d396d147a..d0f0ef9add 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1309,10 +1309,73 @@ void customize(std::vector<ConfigParamSpec>& workflowOptions)
 ```
 
 ## Reference data
-TODO
-- PP task -> pointer
-- Checker -> if PP -> pointer
-- Checker on TH1 -> describe here
+
+A reference object is an object from a previous run. It is usually used as a point of comparison. 
+
+### Get a reference plot
+
+To retrieve a reference plot in your Check, use 
+```
+  std::shared_ptr<MonitorObject> retrieveReference(std::string path, int referenceRun, Activity activity);
+```
+- `path` : the path of the object _without the provenance (e.g. `qc`)
+- `referenceRun` : the run of reference
+- `activity` : the current activity
+
+If the reference is not found it will return a `nullptr` and issue a warning. 
+
+### Compare to a reference plot
+
+The check `ReferenceComparatorCheck` in `Common` compares objects to their reference. 
+
+TODO beautify
+
+The configuration looks like 
+```
+      "QcCheck": {
+        "active": "true",
+        "className": "o2::quality_control_modules::common::ReferenceComparatorCheck",
+        "moduleName": "QcCommon",
+        "policy": "OnAny",
+        "detectorName": "TST",
+        "dataSource": [{
+          "type": "Task",
+          "name": "QcTask",
+          "MOs": ["example"]
+        }],
+        "extendedCheckParameters": {
+          "default": {
+            "default": {
+              "referenceRun" : "500",
+              "moduleName" : "QualityControl",
+              "comparatorName" : "o2::quality_control_modules::common::ObjectComparatorChi2",
+              "threshold" : "0.5"
+            }
+          },
+          "PHYSICS": {
+            "PROTON-PROTON": {
+              "referenceRun" : "551890"
+            }
+          }
+        }
+      }
+```
+The check needs the following parameters
+- `referenceRun` to specify what is the run of reference and retrieve the reference data. 
+- `comparatorName` to decide how to compare, see below for their descriptions.
+- `threshold` to specifie the value used to discriminate between good and bad matches between the histograms.
+
+Three comparator are provided:
+1. `o2::quality_control_modules::common::ObjectComparatorDeviation`: comparison based on the average relative deviation between the bins of the current and reference histograms; the `threshold` parameter represent in this case the maximum allowed deviation
+2. `o2::quality_control_modules::common::ObjectComparatorChi2`: comparison based on a standard chi2 test between the current and reference histograms; the `threshold` parameter represent in this case the minimum allowed chi2 probability
+3. `o2::quality_control_modules::common::ObjectComparatorKolmogorov`: comparison based on a standard Kolmogorov test between the current and reference histograms; the `threshold` parameter represent in this case the minimum allowed Kolmogorov probability
+
+Note that you can easily specify different reference runs for different run types and beam types. 
+
+### Generate a canvas combining both the current and reference ratio histogram
+
+The postprocessing task ReferenceComparatorTask draws a given set of plots in comparison with their corresponding references, both as superimposed histograms and as current/reference ratio histograms.
+See the details [here](https://github.com/AliceO2Group/QualityControl/blob/master/doc/PostProcessing.md#the-referencecomparatortask-class).
 
 ## Configuration files details
 

From d23cfcd9e58feb4836d72f61b10896bd9826ad4e Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 26 Jun 2024 12:22:25 +0200
Subject: [PATCH 04/25] Format

---
 .../Common/src/ReferenceComparatorCheck.cxx   | 45 ++++++++++++-------
 1 file changed, 28 insertions(+), 17 deletions(-)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 038aef6ca6..4b5edda813 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -148,12 +148,12 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
 
   auto referencePlot = retrieveReference(path, referenceRun, mActivity);
   if (!referencePlot) {
-    ILOG(Warning, Ops) << "The reference plot is empty" << ENDM;
+    message = "The reference plot is empty";
     return Quality::Null;
   }
   auto* ref = dynamic_cast<TH1*>(referencePlot->getObject());
   if (!ref) {
-    ILOG(Warning, Ops) << "The reference plot is not a TH1" << ENDM;
+    message = "The reference plot is not a TH1";
     return Quality::Null;
   }
   return mComparator.get()->compare(th1, ref, message);
@@ -226,6 +226,23 @@ static int getQualityColor(const Quality& q)
   return 0;
 }
 
+static void updateQualityLabel(TPaveText* label, const Quality& quality)
+{
+  // draw the quality label with the text color corresponding to the quality level
+  label->SetTextColor(getQualityColor(quality));
+  label->AddText(quality.getName().c_str());
+
+  // add the first flag below the quality label, or an empty line if no flags are set
+  auto flags = quality.getFlags();
+  std::string message = flags.empty() ? "" : flags.front().second;
+  auto pos = message.find(" ");
+  if (pos != std::string::npos) {
+    message.erase(0, pos + 1);
+  }
+  auto* text = label->AddText(message.c_str());
+  text->SetTextColor(kGray + 1);
+}
+
 // Write the quality level and flags in the existing PaveText inside the canvas
 static void setQualityLabel(TCanvas* canvas, const Quality& quality)
 {
@@ -244,26 +261,14 @@ static void setQualityLabel(TCanvas* canvas, const Quality& quality)
       continue;
     }
 
-    // draw the quality label with the text color corresponding to the quality level
-    label->SetTextColor(getQualityColor(quality));
-    label->AddText(quality.getName().c_str());
-
-    // add the first flag below the quality label, or an empty line if no flags are set
-    auto flags = quality.getFlags();
-    std::string message = flags.empty() ? "" : flags.front().second;
-    auto pos = message.find(" ");
-    if (pos != std::string::npos) {
-      message.erase(0, pos + 1);
-    }
-    auto* text = label->AddText(message.c_str());
-    text->SetTextColor(kGray + 1);
-
+    updateQualityLabel(label, quality);
     break;
   }
 }
 
 void ReferenceComparatorCheck::beautify(std::shared_ptr<MonitorObject> mo, Quality checkResult)
 {
+  std::cout << "beautify" << std::endl;
   // get the quality associated to the current MO
   auto moName = mo->getName();
   auto quality = mQualityFlags[moName];
@@ -279,7 +284,13 @@ void ReferenceComparatorCheck::beautify(std::shared_ptr<MonitorObject> mo, Quali
     // draw the quality label on the plot
     setQualityLabel(canvas, quality);
   }
-  // TODO handle the case of simple MO
+  auto* th1 = dynamic_cast<TH1*>(mo->getObject());
+  std::cout << "th1 : " << th1 << std::endl;
+  if(th1) {
+    auto* qualityLabel = new TPaveText(0.75, 0.65, 0.98, 0.75, "brNDC");
+    updateQualityLabel(qualityLabel, quality);
+    th1->GetListOfFunctions()->Add(qualityLabel);
+  }
 }
 
 } // namespace o2::quality_control_modules::common

From 714a48620e4e7fbd65e39b7076878046ad175024 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 26 Jun 2024 15:16:18 +0200
Subject: [PATCH 05/25] Format

---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 4b5edda813..9609d59481 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -286,7 +286,7 @@ void ReferenceComparatorCheck::beautify(std::shared_ptr<MonitorObject> mo, Quali
   }
   auto* th1 = dynamic_cast<TH1*>(mo->getObject());
   std::cout << "th1 : " << th1 << std::endl;
-  if(th1) {
+  if (th1) {
     auto* qualityLabel = new TPaveText(0.75, 0.65, 0.98, 0.75, "brNDC");
     updateQualityLabel(qualityLabel, quality);
     th1->GetListOfFunctions()->Add(qualityLabel);

From 466a984790dbc5c66d8eb7813fc277be83d2965e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Wed, 26 Jun 2024 15:45:36 +0200
Subject: [PATCH 06/25] cout

---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 9609d59481..7c8403598b 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -268,7 +268,6 @@ static void setQualityLabel(TCanvas* canvas, const Quality& quality)
 
 void ReferenceComparatorCheck::beautify(std::shared_ptr<MonitorObject> mo, Quality checkResult)
 {
-  std::cout << "beautify" << std::endl;
   // get the quality associated to the current MO
   auto moName = mo->getName();
   auto quality = mQualityFlags[moName];

From a1ad04444617e0c92e1473e4be901763e6afd8ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Wed, 26 Jun 2024 15:46:07 +0200
Subject: [PATCH 07/25] Update ReferenceComparatorCheck.cxx

---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 7c8403598b..c1ab102789 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -284,7 +284,6 @@ void ReferenceComparatorCheck::beautify(std::shared_ptr<MonitorObject> mo, Quali
     setQualityLabel(canvas, quality);
   }
   auto* th1 = dynamic_cast<TH1*>(mo->getObject());
-  std::cout << "th1 : " << th1 << std::endl;
   if (th1) {
     auto* qualityLabel = new TPaveText(0.75, 0.65, 0.98, 0.75, "brNDC");
     updateQualityLabel(qualityLabel, quality);

From 4755f09a329a575aafe3129c4e7c12e9c30b1121 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Wed, 26 Jun 2024 15:46:59 +0200
Subject: [PATCH 08/25] Update Advanced.md

---
 doc/Advanced.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/Advanced.md b/doc/Advanced.md
index d0f0ef9add..9ae8282b35 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1312,13 +1312,13 @@ void customize(std::vector<ConfigParamSpec>& workflowOptions)
 
 A reference object is an object from a previous run. It is usually used as a point of comparison. 
 
-### Get a reference plot
+### Get a reference plot in a check
 
 To retrieve a reference plot in your Check, use 
 ```
   std::shared_ptr<MonitorObject> retrieveReference(std::string path, int referenceRun, Activity activity);
 ```
-- `path` : the path of the object _without the provenance (e.g. `qc`)
+- `path` : the path of the object _without the provenance (e.g. `qc`)_
 - `referenceRun` : the run of reference
 - `activity` : the current activity
 

From d6cb6e1f4b7e8fa805c8819770de0b696c656145 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Wed, 26 Jun 2024 15:48:29 +0200
Subject: [PATCH 09/25] Update Advanced.md

---
 doc/Advanced.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/Advanced.md b/doc/Advanced.md
index 9ae8282b35..ae39a88e7f 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1322,14 +1322,12 @@ To retrieve a reference plot in your Check, use
 - `referenceRun` : the run of reference
 - `activity` : the current activity
 
-If the reference is not found it will return a `nullptr` and issue a warning. 
+If the reference is not found it will return a `nullptr` and the quality is `Null`.
 
 ### Compare to a reference plot
 
 The check `ReferenceComparatorCheck` in `Common` compares objects to their reference. 
 
-TODO beautify
-
 The configuration looks like 
 ```
       "QcCheck": {
@@ -1372,6 +1370,8 @@ Three comparator are provided:
 
 Note that you can easily specify different reference runs for different run types and beam types. 
 
+The plot is beautified by the addition of a `TPaveText` containing the quality and the reason for the quality. 
+
 ### Generate a canvas combining both the current and reference ratio histogram
 
 The postprocessing task ReferenceComparatorTask draws a given set of plots in comparison with their corresponding references, both as superimposed histograms and as current/reference ratio histograms.

From 6f9e9ef4217e726ded84e7bafe31cdac313abe2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Wed, 26 Jun 2024 15:50:40 +0200
Subject: [PATCH 10/25] Update DevelopersTips.md

---
 doc/DevelopersTips.md | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/doc/DevelopersTips.md b/doc/DevelopersTips.md
index 9bbc281887..6fd8b8f4f0 100644
--- a/doc/DevelopersTips.md
+++ b/doc/DevelopersTips.md
@@ -143,10 +143,6 @@ firewall-cmd --reload
 10. Set the monitoring url to `"url": "stdout://?qc,influxdb-udp://flptest1.cern.ch:8089"`
 11. Once the dashboard is ready, tell Adam.
 
-ALTERNATIVELY
-
-use http://alio2-bld4-mx-dev01-gpn:3000/?orgId=1 (admin and pwd like above)
-
 ### Monitoring setup for building the grafana dashboard with prod data
 
 1. Go to http://pcald24.cern.ch:3000/?orgId=1

From 142565fd75fcb873905039220d6b5dd8e6052e93 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Mon, 1 Jul 2024 13:27:35 +0200
Subject: [PATCH 11/25] Update
 Framework/include/QualityControl/ReferenceUtils.h

Co-authored-by: Piotr Konopka <piotr.jan.konopka@cern.ch>
---
 Framework/include/QualityControl/ReferenceUtils.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 2f096ac9b3..67b476124a 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -25,7 +25,7 @@
 #include "QualityControl/QcInfoLogger.h"
 #include "QualityControl/RepoPathUtils.h"
 
-namespace o2::quality_control_modules::common
+namespace o2::quality_control::checker
 {
 
 //_________________________________________________________________________________________

From 71e7460315d43b189fbf689a6028a2b4464e05d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Mon, 1 Jul 2024 13:28:29 +0200
Subject: [PATCH 12/25] Update Modules/Common/src/ReferenceComparatorCheck.cxx

Co-authored-by: Piotr Konopka <piotr.jan.konopka@cern.ch>
---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index c1ab102789..de6496b72a 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -181,7 +181,7 @@ Quality ReferenceComparatorCheck::check(std::map<std::string, std::shared_ptr<Mo
       // We got a plot, we have to find the reference before calling the comparator
       quality = getSinglePlotQuality(mo, message);
     } else {
-      ILOG(Warning, Ops) << "mo is not a TCanvas or a TH1" << ENDM;
+      ILOG(Warning, Ops) << "Compared Monitor Object '" << mo->getName() << "' is not a TCanvas or a TH1, the detector QC responsible should review the configuration" << ENDM;
       continue;
     }
 

From 591aa8651c97670e7288ae43ce8b79ca93d8aac2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Mon, 1 Jul 2024 13:28:44 +0200
Subject: [PATCH 13/25] Update doc/Advanced.md

Co-authored-by: Piotr Konopka <piotr.jan.konopka@cern.ch>
---
 doc/Advanced.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/Advanced.md b/doc/Advanced.md
index 1f2a773f45..65545bc6c4 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1453,7 +1453,7 @@ The check needs the following parameters
 - `comparatorName` to decide how to compare, see below for their descriptions.
 - `threshold` to specifie the value used to discriminate between good and bad matches between the histograms.
 
-Three comparator are provided:
+Three comparators are provided:
 1. `o2::quality_control_modules::common::ObjectComparatorDeviation`: comparison based on the average relative deviation between the bins of the current and reference histograms; the `threshold` parameter represent in this case the maximum allowed deviation
 2. `o2::quality_control_modules::common::ObjectComparatorChi2`: comparison based on a standard chi2 test between the current and reference histograms; the `threshold` parameter represent in this case the minimum allowed chi2 probability
 3. `o2::quality_control_modules::common::ObjectComparatorKolmogorov`: comparison based on a standard Kolmogorov test between the current and reference histograms; the `threshold` parameter represent in this case the minimum allowed Kolmogorov probability

From 55237985286affd9044669fdf2677861f2b5bb06 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Mon, 1 Jul 2024 13:29:28 +0200
Subject: [PATCH 14/25] Update doc/Advanced.md

Co-authored-by: Piotr Konopka <piotr.jan.konopka@cern.ch>
---
 doc/Advanced.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/Advanced.md b/doc/Advanced.md
index 65545bc6c4..7009f5ee07 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1406,7 +1406,7 @@ A reference object is an object from a previous run. It is usually used as a poi
 
 To retrieve a reference plot in your Check, use 
 ```
-  std::shared_ptr<MonitorObject> retrieveReference(std::string path, int referenceRun, Activity activity);
+  std::shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, int referenceRun, Activity activity);
 ```
 - `path` : the path of the object _without the provenance (e.g. `qc`)_
 - `referenceRun` : the run of reference

From 81a00d1380945acbe92b8146363ac1b033bce75e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Mon, 1 Jul 2024 13:38:58 +0200
Subject: [PATCH 15/25] Update ReferenceComparatorCheck.cxx

---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index de6496b72a..47c757474b 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -137,6 +137,10 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
 {
   // retrieve the reference plot and compare
   auto* th1 = dynamic_cast<TH1*>(mo->getObject());
+  if (th1 == nullptr) {
+    message = "The MonitorObject is not a TH1";
+    return Quality::Null;
+  }
   auto referenceRun = std::stoi(mCustomParameters.atOptional("referenceRun").value_or("0"));
 
   // get path of mo and ref (we have to remove the provenance)

From 5262cce5043e2308114ad4a34446597eba557af3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barth=C3=A9l=C3=A9my=20von=20Haller?=
 <barthelemy.von.haller@gmail.com>
Date: Mon, 1 Jul 2024 13:40:45 +0200
Subject: [PATCH 16/25] Update ReferenceComparatorCheck.cxx

---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 47c757474b..990ea46b9c 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -27,6 +27,8 @@
 
 #include <Framework/ServiceRegistryRef.h>
 
+#include <TClass.h>
+
 // ROOT
 #include <TH1.h>
 #include <TCanvas.h>

From ee3757177a087b3f374626244d01babb8ea90547 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Mon, 1 Jul 2024 13:50:48 +0200
Subject: [PATCH 17/25] - use int for the run - update the namespaces

---
 Framework/include/QualityControl/ReferenceUtils.h | 2 +-
 Framework/src/CheckInterface.cxx                  | 2 +-
 Modules/Common/src/ReferenceComparatorTask.cxx    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 67b476124a..9e580b1528 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -32,7 +32,7 @@ namespace o2::quality_control::checker
 //
 // Get the reference plot for a given MonitorObject path
 
-static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath, uint32_t referenceRun, quality_control::core::Activity activity)
+static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath, int referenceRun, quality_control::core::Activity activity)
 {
   uint64_t timeStamp = 0;
   activity.mId = referenceRun;
diff --git a/Framework/src/CheckInterface.cxx b/Framework/src/CheckInterface.cxx
index bdc7c0cf5f..aa6b11eba7 100644
--- a/Framework/src/CheckInterface.cxx
+++ b/Framework/src/CheckInterface.cxx
@@ -62,7 +62,7 @@ void CheckInterface::endOfActivity(const Activity& activity)
 
 shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, int referenceRun, Activity activity)
 {
-  return quality_control_modules::common::getReferencePlot(mDatabase.get(), path, referenceRun, activity);
+  return o2::quality_control::checker::getReferencePlot(mDatabase.get(), path, referenceRun, activity);
 }
 
 } // namespace o2::quality_control::checker
diff --git a/Modules/Common/src/ReferenceComparatorTask.cxx b/Modules/Common/src/ReferenceComparatorTask.cxx
index 537bca0500..527070c503 100644
--- a/Modules/Common/src/ReferenceComparatorTask.cxx
+++ b/Modules/Common/src/ReferenceComparatorTask.cxx
@@ -120,7 +120,7 @@ void ReferenceComparatorTask::initialize(quality_control::postprocessing::Trigge
       auto fullOutPath = group.outputPath + "/" + path;
 
       // retrieve the reference MO
-      auto referencePlot = getReferencePlot(&qcdb, fullRefPath, mReferenceRun, trigger.activity);
+      auto referencePlot = o2::quality_control::checker::getReferencePlot(&qcdb, fullRefPath, mReferenceRun, trigger.activity);
       if (!referencePlot) {
         continue;
       }

From 3c62749822a7a0c60dc6c2312c2e82d32c0a900c Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Mon, 1 Jul 2024 13:53:26 +0200
Subject: [PATCH 18/25] format

---
 Framework/include/QualityControl/ReferenceUtils.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 9e580b1528..19697ce650 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -14,8 +14,8 @@
 /// \author Andrea Ferrero and Barthelemy von Haller
 ///
 
-#ifndef QUALITYCONTROL_ReferenceComparatorUtils_H
-#define QUALITYCONTROL_ReferenceComparatorUtils_H
+#ifndef QUALITYCONTROL_ReferenceUtils_H
+#define QUALITYCONTROL_ReferenceUtils_H
 
 #include <memory>
 #include "QualityControl/MonitorObject.h"
@@ -53,6 +53,6 @@ static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(qu
   return qcdb->retrieveMO(path, name, timeStamp, activity);
 }
 
-} // namespace o2::quality_control_modules::common
+} // namespace o2::quality_control::checker
 
-#endif // QUALITYCONTROL_ReferenceComparatorUtils_H
+#endif // QUALITYCONTROL_ReferenceUtils_H

From da08db6a3053d6f9f73099c1d699c55825b20705 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Mon, 1 Jul 2024 14:38:45 +0200
Subject: [PATCH 19/25] return a tuple

---
 .../include/QualityControl/ReferenceUtils.h     |  8 ++++----
 .../include/QualityControl/RepoPathUtils.h      | 17 ++++++++++++-----
 Modules/Common/src/ReferenceComparatorTask.cxx  |  5 ++---
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 19697ce650..97fc86f0bd 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -32,7 +32,8 @@ namespace o2::quality_control::checker
 //
 // Get the reference plot for a given MonitorObject path
 
-static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath, int referenceRun, quality_control::core::Activity activity)
+static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath,
+                                                                              int referenceRun, quality_control::core::Activity activity)
 {
   uint64_t timeStamp = 0;
   activity.mId = referenceRun;
@@ -45,9 +46,8 @@ static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(qu
     return nullptr;
   }
 
-  std::string path;
-  std::string name;
-  if (!o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath, path, name)) {
+  auto [success, path, name] = o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath);
+  if (!success) {
     return nullptr;
   }
   return qcdb->retrieveMO(path, name, timeStamp, activity);
diff --git a/Framework/include/QualityControl/RepoPathUtils.h b/Framework/include/QualityControl/RepoPathUtils.h
index af3a627577..389ea0da75 100644
--- a/Framework/include/QualityControl/RepoPathUtils.h
+++ b/Framework/include/QualityControl/RepoPathUtils.h
@@ -129,17 +129,24 @@ class RepoPathUtils
   static constexpr auto allowedProvenancesMessage = R"(Allowed provenances are "qc" (real data processed synchronously), "qc_async" (real data processed asynchronously) and "qc_mc" (simulated data).)";
   static bool isProvenanceAllowed(const std::string& provenance);
 
-  static bool splitObjectPath(const std::string& fullPath, std::string& path, std::string& name)
+  /**
+   * Splits the provided path and returns both the base path and the object name.
+   * @param fullPath
+   * @return A tuple with 1. a boolean to specify if we succeeded (i.e. whether we found a `/`)
+   *                      2. the path
+   *                      3. the object name
+   */
+  static std::tuple<bool, std::string, std::string> splitObjectPath(const std::string& fullPath)
   {
     std::string delimiter = "/";
     std::string det;
     size_t pos = fullPath.rfind(delimiter);
     if (pos == std::string::npos) {
-      return false;
+      return {false, "", ""};
     }
-    path = fullPath.substr(0, pos);
-    name = fullPath.substr(pos + 1);
-    return true;
+    std::string path = fullPath.substr(0, pos);
+    std::string name = fullPath.substr(pos + 1);
+    return {true, path, name};
   }
 };
 } // namespace o2::quality_control::core
diff --git a/Modules/Common/src/ReferenceComparatorTask.cxx b/Modules/Common/src/ReferenceComparatorTask.cxx
index 527070c503..9f63668240 100644
--- a/Modules/Common/src/ReferenceComparatorTask.cxx
+++ b/Modules/Common/src/ReferenceComparatorTask.cxx
@@ -52,9 +52,8 @@ static std::pair<std::shared_ptr<MonitorObject>, bool> getMO(repository::Databas
     return { nullptr, false };
   }
 
-  std::string path;
-  std::string name;
-  if (!o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath, path, name)) {
+  auto [success, path, name] = o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath);
+  if (!success) {
     return { nullptr, false };
   }
   // retrieve QO from CCDB - do not associate to trigger activity if ignoreActivity is true

From 1ffb5edb85068fd813f58910699deb38723e717b Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Tue, 2 Jul 2024 08:31:36 +0200
Subject: [PATCH 20/25] format

---
 Framework/include/QualityControl/RepoPathUtils.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Framework/include/QualityControl/RepoPathUtils.h b/Framework/include/QualityControl/RepoPathUtils.h
index 389ea0da75..0dce4ce014 100644
--- a/Framework/include/QualityControl/RepoPathUtils.h
+++ b/Framework/include/QualityControl/RepoPathUtils.h
@@ -142,11 +142,11 @@ class RepoPathUtils
     std::string det;
     size_t pos = fullPath.rfind(delimiter);
     if (pos == std::string::npos) {
-      return {false, "", ""};
+      return { false, "", "" };
     }
     std::string path = fullPath.substr(0, pos);
     std::string name = fullPath.substr(pos + 1);
-    return {true, path, name};
+    return { true, path, name };
   }
 };
 } // namespace o2::quality_control::core

From f84803a8c8c0bd65ee39c82985e73bad944ef5d6 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 3 Jul 2024 09:10:56 +0200
Subject: [PATCH 21/25] return null quality if no reference run number is
 provided.

---
 Modules/Common/src/ReferenceComparatorCheck.cxx | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 990ea46b9c..d08af0ce8e 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -143,7 +143,11 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
     message = "The MonitorObject is not a TH1";
     return Quality::Null;
   }
-  auto referenceRun = std::stoi(mCustomParameters.atOptional("referenceRun").value_or("0"));
+  if (mCustomParameters.count("referenceRun") == 0) {
+    message = "No reference run provided";
+    return Quality::Null;
+  }
+  auto referenceRun = std::stoi(mCustomParameters.at("referenceRun"));
 
   // get path of mo and ref (we have to remove the provenance)
   string path = mo->getPath();
@@ -154,7 +158,7 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
 
   auto referencePlot = retrieveReference(path, referenceRun, mActivity);
   if (!referencePlot) {
-    message = "The reference plot is empty";
+    message = "Reference plot not found";
     return Quality::Null;
   }
   auto* ref = dynamic_cast<TH1*>(referencePlot->getObject());

From 3da59955c6e9bbc1e271cb1dd93bf68fcd3bdbc1 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Wed, 3 Jul 2024 10:49:56 +0200
Subject: [PATCH 22/25] extraction

---
 Framework/include/QualityControl/RepoPathUtils.h | 10 ++++++++++
 Modules/Common/src/ReferenceComparatorCheck.cxx  |  6 +-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/Framework/include/QualityControl/RepoPathUtils.h b/Framework/include/QualityControl/RepoPathUtils.h
index 0dce4ce014..bc3445bd8c 100644
--- a/Framework/include/QualityControl/RepoPathUtils.h
+++ b/Framework/include/QualityControl/RepoPathUtils.h
@@ -148,6 +148,16 @@ class RepoPathUtils
     std::string name = fullPath.substr(pos + 1);
     return { true, path, name };
   }
+
+  static std::string getPathNoProvenance(std::shared_ptr<MonitorObject> mo)
+  {
+    std::string path = mo->getPath();
+    size_t pos = path.find('/');
+    if (pos != std::string::npos) {
+      path = path.substr(pos + 1);
+    }
+    return path;
+  }
 };
 } // namespace o2::quality_control::core
 
diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index d08af0ce8e..4f651fa890 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -150,11 +150,7 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
   auto referenceRun = std::stoi(mCustomParameters.at("referenceRun"));
 
   // get path of mo and ref (we have to remove the provenance)
-  string path = mo->getPath();
-  size_t pos = path.find('/');
-  if (pos != std::string::npos) {
-    path = path.substr(pos + 1);
-  }
+  std::string path = RepoPathUtils::getPathNoProvenance(mo);
 
   auto referencePlot = retrieveReference(path, referenceRun, mActivity);
   if (!referencePlot) {

From da17738a23eee6ddedf882ddfc236226673b4826 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Fri, 5 Jul 2024 09:02:13 +0200
Subject: [PATCH 23/25] - Keep the activity parameter but document it - use
 size_t for the run number - use Timestamp::Latest

---
 Framework/include/QualityControl/CheckInterface.h |  7 ++++++-
 Framework/include/QualityControl/ReferenceUtils.h | 15 ++-------------
 Framework/src/CheckInterface.cxx                  |  2 +-
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/Framework/include/QualityControl/CheckInterface.h b/Framework/include/QualityControl/CheckInterface.h
index 394d9488c9..45d2884336 100644
--- a/Framework/include/QualityControl/CheckInterface.h
+++ b/Framework/include/QualityControl/CheckInterface.h
@@ -94,7 +94,12 @@ class CheckInterface : public core::UserCodeInterface
 
   /// \brief Retrieve a reference plot at the provided path, matching the give activity and for the provided run.
   /// the activity is the current one, while the run number is the reference run.
-  std::shared_ptr<MonitorObject> retrieveReference(std::string path, int referenceRun, Activity activity);
+  ///
+  /// \param path path to the object (no provenance)
+  /// \param referenceRun Run number of the reference data
+  /// \param activity Current activity (necessary for the provenance and the pass)
+  /// \return
+  std::shared_ptr<MonitorObject> retrieveReference(std::string path, size_t referenceRun, Activity activity);
 
  private:
   std::shared_ptr<o2::quality_control::repository::DatabaseInterface> mDatabase;
diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 97fc86f0bd..155b077841 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -33,24 +33,13 @@ namespace o2::quality_control::checker
 // Get the reference plot for a given MonitorObject path
 
 static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath,
-                                                                              int referenceRun, quality_control::core::Activity activity)
+                                                                              size_t referenceRun, core::Activity activity)
 {
-  uint64_t timeStamp = 0;
-  activity.mId = referenceRun;
-  const auto filterMetadata = quality_control::core::activity_helpers::asDatabaseMetadata(activity, false);
-  const auto objectValidity = qcdb->getLatestObjectValidity(activity.mProvenance + "/" + fullPath, filterMetadata);
-  if (objectValidity.isValid()) {
-    timeStamp = objectValidity.getMax() - 1;
-  } else {
-    ILOG(Warning, Devel) << "Could not find the object '" << fullPath << "' for run " << activity.mId << ENDM;
-    return nullptr;
-  }
-
   auto [success, path, name] = o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath);
   if (!success) {
     return nullptr;
   }
-  return qcdb->retrieveMO(path, name, timeStamp, activity);
+  return qcdb->retrieveMO(path, name, repository::DatabaseInterface::Timestamp::Latest, activity);
 }
 
 } // namespace o2::quality_control::checker
diff --git a/Framework/src/CheckInterface.cxx b/Framework/src/CheckInterface.cxx
index aa6b11eba7..a3b5d62e98 100644
--- a/Framework/src/CheckInterface.cxx
+++ b/Framework/src/CheckInterface.cxx
@@ -60,7 +60,7 @@ void CheckInterface::endOfActivity(const Activity& activity)
   // noop, override it if you want.
 }
 
-shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, int referenceRun, Activity activity)
+shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, size_t referenceRun, Activity activity)
 {
   return o2::quality_control::checker::getReferencePlot(mDatabase.get(), path, referenceRun, activity);
 }

From 371a1a6341924c444989eba4941ce8000b93cf9c Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Fri, 5 Jul 2024 09:16:34 +0200
Subject: [PATCH 24/25] Use extended parameters.

---
 .../include/Common/ReferenceComparatorCheck.h |  1 +
 .../Common/src/ReferenceComparatorCheck.cxx   | 22 ++++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/Modules/Common/include/Common/ReferenceComparatorCheck.h b/Modules/Common/include/Common/ReferenceComparatorCheck.h
index 200a358d1d..78c6f953b6 100644
--- a/Modules/Common/include/Common/ReferenceComparatorCheck.h
+++ b/Modules/Common/include/Common/ReferenceComparatorCheck.h
@@ -55,6 +55,7 @@ class ReferenceComparatorCheck : public o2::quality_control::checker::CheckInter
   std::map<std::string, Quality> mQualityFlags;
   std::map<std::string, std::shared_ptr<TPaveText>> mQualityLabels;
   quality_control::core::Activity mActivity;
+  size_t mReferenceRun;
 };
 
 } // namespace o2::quality_control_modules::common
diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index 4f651fa890..c239855ef4 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -46,9 +46,10 @@ void ReferenceComparatorCheck::configure()
 
 void ReferenceComparatorCheck::startOfActivity(const Activity& activity)
 {
-  auto moduleName = mCustomParameters.atOptional("moduleName").value_or("");
-  auto comparatorName = mCustomParameters.atOptional("comparatorName").value_or("");
-  double threshold = std::stof(mCustomParameters.atOptional("threshold").value_or("0"));
+  auto moduleName = mCustomParameters.atOptional("moduleName", activity).value_or("");
+  auto comparatorName = mCustomParameters.atOptional("comparatorName", activity).value_or("");
+  double threshold = std::stof(mCustomParameters.atOptional("threshold", activity).value_or("0"));
+  mReferenceRun = std::stoi(mCustomParameters.atOptional("referenceRun", activity).value_or("0"));
 
   mComparator.reset();
   if (!moduleName.empty() && !comparatorName.empty()) {
@@ -143,16 +144,11 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
     message = "The MonitorObject is not a TH1";
     return Quality::Null;
   }
-  if (mCustomParameters.count("referenceRun") == 0) {
-    message = "No reference run provided";
-    return Quality::Null;
-  }
-  auto referenceRun = std::stoi(mCustomParameters.at("referenceRun"));
 
   // get path of mo and ref (we have to remove the provenance)
   std::string path = RepoPathUtils::getPathNoProvenance(mo);
 
-  auto referencePlot = retrieveReference(path, referenceRun, mActivity);
+  auto referencePlot = retrieveReference(path, mReferenceRun, mActivity);
   if (!referencePlot) {
     message = "Reference plot not found";
     return Quality::Null;
@@ -172,7 +168,13 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
 
 Quality ReferenceComparatorCheck::check(std::map<std::string, std::shared_ptr<MonitorObject>>* moMap)
 {
-  Quality result = Quality::Good;
+  Quality result = Quality::Null;
+
+  if (mReferenceRun == 0) {
+    result.addFlag(FlagTypeFactory::Unknown(), "No reference run provided");
+    return result;
+  }
+
   for (auto& [key, mo] : *moMap) {
     auto moName = mo->getName();
     Quality quality;

From fd93cdf8acaa4e1585e69c01154d61c164bc1cd9 Mon Sep 17 00:00:00 2001
From: Barthelemy <barthelemy.von.haller@cern.ch>
Date: Fri, 5 Jul 2024 15:30:38 +0200
Subject: [PATCH 25/25] pass only 1 activity for reference and not the
 reference run + the current activity

---
 Framework/include/QualityControl/CheckInterface.h        | 5 ++---
 Framework/include/QualityControl/ReferenceUtils.h        | 4 ++--
 Framework/src/CheckInterface.cxx                         | 4 ++--
 Modules/Common/include/Common/ReferenceComparatorCheck.h | 2 +-
 Modules/Common/src/ReferenceComparatorCheck.cxx          | 6 ++++--
 Modules/Common/src/ReferenceComparatorTask.cxx           | 4 +++-
 doc/Advanced.md                                          | 5 ++---
 7 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/Framework/include/QualityControl/CheckInterface.h b/Framework/include/QualityControl/CheckInterface.h
index 45d2884336..b1bb206167 100644
--- a/Framework/include/QualityControl/CheckInterface.h
+++ b/Framework/include/QualityControl/CheckInterface.h
@@ -96,10 +96,9 @@ class CheckInterface : public core::UserCodeInterface
   /// the activity is the current one, while the run number is the reference run.
   ///
   /// \param path path to the object (no provenance)
-  /// \param referenceRun Run number of the reference data
-  /// \param activity Current activity (necessary for the provenance and the pass)
+  /// \param referenceActivity Reference activity (usually a copy of the current activity with a different run number)
   /// \return
-  std::shared_ptr<MonitorObject> retrieveReference(std::string path, size_t referenceRun, Activity activity);
+  std::shared_ptr<MonitorObject> retrieveReference(std::string path, Activity referenceActivity);
 
  private:
   std::shared_ptr<o2::quality_control::repository::DatabaseInterface> mDatabase;
diff --git a/Framework/include/QualityControl/ReferenceUtils.h b/Framework/include/QualityControl/ReferenceUtils.h
index 155b077841..5b8f6d7b6f 100644
--- a/Framework/include/QualityControl/ReferenceUtils.h
+++ b/Framework/include/QualityControl/ReferenceUtils.h
@@ -33,13 +33,13 @@ namespace o2::quality_control::checker
 // Get the reference plot for a given MonitorObject path
 
 static std::shared_ptr<quality_control::core::MonitorObject> getReferencePlot(quality_control::repository::DatabaseInterface* qcdb, std::string& fullPath,
-                                                                              size_t referenceRun, core::Activity activity)
+                                                                              core::Activity referenceActivity)
 {
   auto [success, path, name] = o2::quality_control::core::RepoPathUtils::splitObjectPath(fullPath);
   if (!success) {
     return nullptr;
   }
-  return qcdb->retrieveMO(path, name, repository::DatabaseInterface::Timestamp::Latest, activity);
+  return qcdb->retrieveMO(path, name, repository::DatabaseInterface::Timestamp::Latest, referenceActivity);
 }
 
 } // namespace o2::quality_control::checker
diff --git a/Framework/src/CheckInterface.cxx b/Framework/src/CheckInterface.cxx
index a3b5d62e98..445d51e609 100644
--- a/Framework/src/CheckInterface.cxx
+++ b/Framework/src/CheckInterface.cxx
@@ -60,9 +60,9 @@ void CheckInterface::endOfActivity(const Activity& activity)
   // noop, override it if you want.
 }
 
-shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, size_t referenceRun, Activity activity)
+shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, Activity referenceActivity)
 {
-  return o2::quality_control::checker::getReferencePlot(mDatabase.get(), path, referenceRun, activity);
+  return o2::quality_control::checker::getReferencePlot(mDatabase.get(), path, referenceActivity);
 }
 
 } // namespace o2::quality_control::checker
diff --git a/Modules/Common/include/Common/ReferenceComparatorCheck.h b/Modules/Common/include/Common/ReferenceComparatorCheck.h
index 78c6f953b6..9e163f9bd2 100644
--- a/Modules/Common/include/Common/ReferenceComparatorCheck.h
+++ b/Modules/Common/include/Common/ReferenceComparatorCheck.h
@@ -54,7 +54,7 @@ class ReferenceComparatorCheck : public o2::quality_control::checker::CheckInter
   std::unique_ptr<ObjectComparatorInterface> mComparator;
   std::map<std::string, Quality> mQualityFlags;
   std::map<std::string, std::shared_ptr<TPaveText>> mQualityLabels;
-  quality_control::core::Activity mActivity;
+  quality_control::core::Activity mActivity /*current*/, mReferenceActivity;
   size_t mReferenceRun;
 };
 
diff --git a/Modules/Common/src/ReferenceComparatorCheck.cxx b/Modules/Common/src/ReferenceComparatorCheck.cxx
index c239855ef4..3800570252 100644
--- a/Modules/Common/src/ReferenceComparatorCheck.cxx
+++ b/Modules/Common/src/ReferenceComparatorCheck.cxx
@@ -61,6 +61,8 @@ void ReferenceComparatorCheck::startOfActivity(const Activity& activity)
   }
 
   mActivity = activity;
+  mReferenceActivity = activity;
+  mReferenceActivity.mId = mReferenceRun;
 }
 
 void ReferenceComparatorCheck::endOfActivity(const Activity& activity)
@@ -147,8 +149,8 @@ Quality ReferenceComparatorCheck::getSinglePlotQuality(std::shared_ptr<MonitorOb
 
   // get path of mo and ref (we have to remove the provenance)
   std::string path = RepoPathUtils::getPathNoProvenance(mo);
-
-  auto referencePlot = retrieveReference(path, mReferenceRun, mActivity);
+  // todo we could cache the reference plot within a run
+  auto referencePlot = retrieveReference(path, mReferenceActivity);
   if (!referencePlot) {
     message = "Reference plot not found";
     return Quality::Null;
diff --git a/Modules/Common/src/ReferenceComparatorTask.cxx b/Modules/Common/src/ReferenceComparatorTask.cxx
index 9f63668240..6904e571e6 100644
--- a/Modules/Common/src/ReferenceComparatorTask.cxx
+++ b/Modules/Common/src/ReferenceComparatorTask.cxx
@@ -119,7 +119,9 @@ void ReferenceComparatorTask::initialize(quality_control::postprocessing::Trigge
       auto fullOutPath = group.outputPath + "/" + path;
 
       // retrieve the reference MO
-      auto referencePlot = o2::quality_control::checker::getReferencePlot(&qcdb, fullRefPath, mReferenceRun, trigger.activity);
+      auto referenceActivity = trigger.activity;
+      referenceActivity.mId = mReferenceRun;
+      auto referencePlot = o2::quality_control::checker::getReferencePlot(&qcdb, fullRefPath, referenceActivity);
       if (!referencePlot) {
         continue;
       }
diff --git a/doc/Advanced.md b/doc/Advanced.md
index 7009f5ee07..ca6f291bdb 100644
--- a/doc/Advanced.md
+++ b/doc/Advanced.md
@@ -1406,11 +1406,10 @@ A reference object is an object from a previous run. It is usually used as a poi
 
 To retrieve a reference plot in your Check, use 
 ```
-  std::shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, int referenceRun, Activity activity);
+  std::shared_ptr<MonitorObject> CheckInterface::retrieveReference(std::string path, Activity referenceActivity);
 ```
 - `path` : the path of the object _without the provenance (e.g. `qc`)_
-- `referenceRun` : the run of reference
-- `activity` : the current activity
+- `referenceActivity` : the activity of reference (usually the current activity with a different run number)
 
 If the reference is not found it will return a `nullptr` and the quality is `Null`.