From 4bfe939fe35c3b141e25286d4fe041820fc5387b Mon Sep 17 00:00:00 2001
From: Mateusz Jakub Fila <mateusz.jakub.fila@cern.ch>
Date: Mon, 28 Oct 2024 12:48:58 +0100
Subject: [PATCH] add EventCounter algorithm

---
 k4FWCore/components/EventCounter.cpp          | 39 +++++++++++++
 test/k4FWCoreTest/CMakeLists.txt              |  2 +
 test/k4FWCoreTest/options/TestEventCounter.py | 58 +++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 k4FWCore/components/EventCounter.cpp
 create mode 100644 test/k4FWCoreTest/options/TestEventCounter.py

diff --git a/k4FWCore/components/EventCounter.cpp b/k4FWCore/components/EventCounter.cpp
new file mode 100644
index 00000000..59955a4e
--- /dev/null
+++ b/k4FWCore/components/EventCounter.cpp
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2014-2024 Key4hep-Project.
+ *
+ * This file is part of Key4hep.
+ * See https://key4hep.github.io/key4hep-doc/ for further info.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Gaudi/Accumulators.h"
+#include "Gaudi/Functional/Consumer.h"
+
+class EventCounter final : public Gaudi::Functional::Consumer<void(const EventContext&)> {
+public:
+  using Consumer::Consumer;
+
+  void operator()(const EventContext& ctx) const override {
+    ++m_count;
+    if ((m_frequency > 0) && (ctx.evt() % m_frequency == 0)) {
+      info() << "Processing event " << ctx.evt() << endmsg;
+    }
+  }
+
+private:
+  mutable Gaudi::Accumulators::Counter<> m_count{this, "count"};
+  Gaudi::Property<int>                   m_frequency{this, "Frequency", 1, "How often to print the event number"};
+};
+
+DECLARE_COMPONENT(EventCounter)
diff --git a/test/k4FWCoreTest/CMakeLists.txt b/test/k4FWCoreTest/CMakeLists.txt
index 6d48d076..f1edba33 100644
--- a/test/k4FWCoreTest/CMakeLists.txt
+++ b/test/k4FWCoreTest/CMakeLists.txt
@@ -139,6 +139,8 @@ add_test_with_env(Testk4runCustomArguments options/TestArgs.py --foo=42 PROPERTI
 add_test_with_env(Testk4runVerboseOutput options/TestArgs.py --verbose PROPERTIES PASS_REGULAR_EXPRESSION " VERBOSE ")
 add_test_with_env(Testk4runHelpOnly options/TestArgs.py --help PROPERTIES PASS_REGULAR_EXPRESSION "show this help message and exit")
 
+add_test_with_env(TestEventCounter options/TestEventCounter.py)
+set_tests_properties(TestEventCounter PROPERTIES FAIL_REGULAR_EXPRESSION "Processing event 1;Processing event 3" PASS_REGULAR_EXPRESSION "Processing event 0.*Processing event 2;Processing event 2.*Processing event 0")
 
 add_test_with_env(FunctionalMemory options/ExampleFunctionalMemory.py)
 add_test_with_env(FunctionalMTMemory options/ExampleFunctionalMTMemory.py)
diff --git a/test/k4FWCoreTest/options/TestEventCounter.py b/test/k4FWCoreTest/options/TestEventCounter.py
new file mode 100644
index 00000000..96e93e12
--- /dev/null
+++ b/test/k4FWCoreTest/options/TestEventCounter.py
@@ -0,0 +1,58 @@
+#
+# Copyright (c) 2014-2024 Key4hep-Project.
+#
+# This file is part of Key4hep.
+# See https://key4hep.github.io/key4hep-doc/ for further info.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# This is an example of counting events with EventCounter algorithm.
+# During execution the EventCounter algorithms will printout current event number depending on the frequency.
+# The summary about total number of events passed through that algorithms is handled by MessageSvcSink
+
+from Gaudi.Configuration import INFO, WARNING
+from Configurables import EventCounter
+from Configurables import HiveSlimEventLoopMgr, HiveWhiteBoard, AvalancheSchedulerSvc
+from k4FWCore import ApplicationMgr
+
+evtslots = 4
+threads = 4
+
+whiteboard = HiveWhiteBoard(
+    "EventDataSvc",
+    EventSlots=evtslots,
+    ForceLeaves=True,
+)
+
+slimeventloopmgr = HiveSlimEventLoopMgr(
+    "HiveSlimEventLoopMgr",
+    SchedulerName="AvalancheSchedulerSvc",
+    Warnings=False,
+    OutputLevel=WARNING,
+)
+
+scheduler = AvalancheSchedulerSvc(ThreadPoolSize=threads, ShowDataFlow=True, OutputLevel=WARNING)
+
+counter_1 = EventCounter("SilentEventCounter", Frequency=0, OutputLevel=INFO)
+counter_2 = EventCounter("EventCounter", Frequency=2, OutputLevel=INFO)
+
+
+mgr = ApplicationMgr(
+    TopAlg=[counter_1, counter_2],
+    EvtSel="NONE",
+    EvtMax=4,
+    ExtSvc=[whiteboard, "Gaudi::Monitoring::MessageSvcSink"],
+    EventLoop=slimeventloopmgr,
+    OutputLevel=INFO,
+)