Fix accessing input file metadata in MetadataSvc

k4FWCore/components/MetadataSvc.cpp

@@ -38,14 +38,13 @@ StatusCode MetadataSvc::initialize() {
     error() << "Unable to locate the EventDataSvc" << endmsg;
     return StatusCode::FAILURE;
   }
-
-  m_frame = std::make_unique<podio::Frame>();
-
   return StatusCode::SUCCESS;
 }
 
 StatusCode MetadataSvc::finalize() { return Service::finalize(); }
 
-void MetadataSvc::setFrame(podio::Frame&& fr) { m_frame = std::make_unique<podio::Frame>(std::move(fr)); }
+const podio::Frame* MetadataSvc::getFrame() const { return m_frame.get(); }
+podio::Frame*       MetadataSvc::getFrame() { return m_frame.get(); }
+void MetadataSvc::setFrame(podio::Frame&& frame) { m_frame = std::make_unique<podio::Frame>(std::move(frame)); }
 
 DECLARE_COMPONENT(MetadataSvc)

k4FWCore/components/MetadataSvc.h

@@ -26,6 +26,8 @@
 
 #include "k4FWCore/IMetadataSvc.h"
 
+#include <memory>
+
 class MetadataSvc : public extends<Service, IMetadataSvc> {
   using extends::extends;
 
@@ -38,7 +40,9 @@ class MetadataSvc : public extends<Service, IMetadataSvc> {
 
   std::unique_ptr<podio::Frame> m_frame;
 
-  void setFrame(podio::Frame&& frame) override;
+  const podio::Frame* getFrame() const override;
+  podio::Frame*       getFrame() override;
+  void                setFrame(podio::Frame&& frame) override;
 };
 
 #endif

k4FWCore/components/Writer.cpp

@@ -34,6 +34,7 @@
 
 #include <GaudiKernel/IHiveWhiteBoard.h>
 #include <memory>
+#include <utility>
 
 class Writer final : public Gaudi::Functional::Consumer<void(const EventContext&)> {
 public:
@@ -121,8 +122,8 @@ class Writer final : public Gaudi::Functional::Consumer<void(const EventContext&
     }
     iosvc->getWriter()->writeFrame(config_metadata_frame, "configuration_metadata");
 
-    if (m_metadataSvc->m_frame) {
-      iosvc->getWriter()->writeFrame(*std::move(m_metadataSvc->m_frame), podio::Category::Metadata);
+    if (const auto* metadata_frame = std::as_const(*m_metadataSvc).getFrame(); metadata_frame) {
+      iosvc->getWriter()->writeFrame(*metadata_frame, podio::Category::Metadata);
     }
 
     iosvc->deleteWriter();

k4FWCore/include/k4FWCore/IMetadataSvc.h

@@ -19,8 +19,6 @@
 #ifndef FWCORE_IMETADATASERVICE_H
 #define FWCORE_IMETADATASERVICE_H
 
-#include <memory>
-
 #include "GaudiKernel/IInterface.h"
 
 #include "podio/Frame.h"
@@ -29,16 +27,26 @@ class IMetadataSvc : virtual public IInterface {
 public:
   DeclareInterfaceID(IMetadataSvc, 1, 0);
 
-  std::unique_ptr<podio::Frame> m_frame;
+  virtual const podio::Frame* getFrame() const               = 0;
+  virtual void                setFrame(podio::Frame&& frame) = 0;
 
-  virtual void               setFrame(podio::Frame&& fr) = 0;
   template <typename T> void put(const std::string& name, const T& obj) {
-    if (!m_frame) {
-      m_frame = std::make_unique<podio::Frame>();
+    if (!getFrame()) {
+      setFrame(podio::Frame{});
     }
-    m_frame->putParameter(name, obj);
+    getFrame()->putParameter(name, obj);
   }
-  template <typename T> std::optional<T> get(const std::string& name) { return m_frame->getParameter<T>(name); }
+
+  template <typename T> std::optional<T> get(const std::string& name) const {
+    const auto* frame = getFrame();
+    if (!frame) {
+      return std::nullopt;
+    }
+    return frame->getParameter<T>(name);
+  }
+
+protected:
+  virtual podio::Frame* getFrame() = 0;
 };
 
 #endif

test/k4FWCoreTest/CMakeLists.txt

@@ -136,15 +136,18 @@ add_test_with_env(FunctionalTransformerHist options/ExampleFunctionalTransformer
 add_test_with_env(FunctionalCollectionMerger options/ExampleFunctionalCollectionMerger.py)
 add_test_with_env(FunctionalFilterFile options/ExampleFunctionalFilterFile.py)
 add_test_with_env(FunctionalMetadata options/ExampleFunctionalMetadata.py)
+add_test_with_env(FunctionalMetadataRead options/ExampleFunctionalMetadataRead.py PROPERTIES DEPENDS FunctionalMetadata)
 add_test_with_env(FunctionalMetadataOldAlgorithm options/ExampleFunctionalMetadataOldAlgorithm.py)
 add_test_with_env(createEventHeaderConcurrent options/createEventHeaderConcurrent.py)
+add_test_with_env(FunctionalMetadataReadOldAlgorithm options/ExampleFunctionalMetadataReadOldAlgorithm.py PROPERTIES DEPENDS ExampleFunctionalMetadataOldAlgorithm)
 
 add_test_with_env(FunctionalWrongImport options/ExampleFunctionalWrongImport.py)
 set_tests_properties(FunctionalWrongImport PROPERTIES PASS_REGULAR_EXPRESSION "ImportError: Importing ApplicationMgr or IOSvc from Configurables is not allowed.")
 add_test_with_env(FunctionalReadNthEvent options/ExampleFunctionalReadNthEvent.py)
 
 add_test(NAME FunctionalCheckFiles COMMAND python3 ${CMAKE_CURRENT_LIST_DIR}/options/CheckOutputFiles.py)
-set_tests_properties(FunctionalCheckFiles PROPERTIES DEPENDS "FunctionalFile;FunctionalMTFile;FunctionalMultipleFile;FunctionalOutputCommands;FunctionalProducerAbsolutePath;FunctionalTransformerRuntimeEmpty;FunctionalMix;FunctionalMixIOSvc;FunctionalTransformerHist;FunctionalCollectionMerger;FunctionalFilterFile;FunctionalMetadata;FunctionalMetadataOldAlgorithm;createEventHeaderConcurrent;FunctionalReadNthEvent")
+
+set_tests_properties(FunctionalCheckFiles PROPERTIES DEPENDS "FunctionalFile;FunctionalMTFile;FunctionalMultipleFile;FunctionalOutputCommands;FunctionalProducerAbsolutePath;FunctionalTransformerRuntimeEmpty;FunctionalMix;FunctionalMixIOSvc;FunctionalTransformerHist;FunctionalCollectionMerger;FunctionalFilterFile;FunctionalMetadata;FunctionalMetadataRead;FunctionalMetadataOldAlgorithm;FunctionalMetadataReadOldAlgorithm;createEventHeaderConcurrent;FunctionalReadNthEvent")
 
 # Do this after checking the files not to overwrite them
 add_test_with_env(FunctionalFile_toolong options/ExampleFunctionalFile.py -n 999 PROPERTIES DEPENDS FunctionalCheckFiles PASS_REGULAR_EXPRESSION

test/k4FWCoreTest/options/CheckOutputFiles.py

@@ -58,6 +58,17 @@ def check_events(filename, number):
         raise RuntimeError("Number of events does not match expected number")
 
 
+def check_metadata(filename, expected_metadata):
+    print(f'Checking file "{filename}" for metadata')
+    podio_reader = podio.root_io.Reader(filename)
+    metadata = podio_reader.get("metadata")[0]
+    for key, value in expected_metadata.items():
+        if (metaval := metadata.get_parameter(key)) != value:
+            raise RuntimeError(
+                f"Metadata parameter {key} does not match the expected value, got {metaval} but expected {value}"
+            )
+
+
 check_collections("functional_transformer.root", ["MCParticles", "NewMCParticles"])
 check_collections(
     "functional_transformer_multiple.root",
@@ -161,33 +172,41 @@ def check_events(filename, number):
 
 check_collections("functional_metadata.root", ["MCParticles"])
 
-reader = podio.root_io.Reader("functional_metadata.root")
-metadata = reader.get("metadata")[0]
-for key, value in zip(
-    [
-        "NumberOfParticles",
-        "ParticleTime",
-        "PDGValues",
-        "MetadataString",
-        "FinalizeMetadataInt",
-    ],
-    [3, 1.5, [1, 2, 3, 4], "hello", 10],
-):
-    if metadata.get_parameter(key) != value:
-        raise RuntimeError(
-            f"Metadata parameter {key} does not match the expected value, got {metadata.get_parameter(key)} but expected {value}"
-        )
+check_metadata(
+    "functional_metadata.root",
+    {
+        "NumberOfParticles": 3,
+        "ParticleTime": 1.5,
+        "PDGValues": [1, 2, 3, 4],
+        "MetadataString": "hello",
+        "FinalizeMetadataInt": 10,
+    },
+)
 
-reader = podio.root_io.Reader("functional_metadata_old_algorithm.root")
-metadata = reader.get("metadata")[0]
-for key, value in zip(
-    ["SimTrackerHits__CellIDEncoding"],
-    ["M:3,S-1:3,I:9,J:9,K-1:6"],
-):
-    if metadata.get_parameter(key) != value:
-        raise RuntimeError(
-            f"Metadata parameter {key} does not match the expected value, got {metadata.get_parameter(key)} but expected {value}"
-        )
+check_metadata(
+    "functional_metadata_propagate.root",
+    {
+        "NumberOfParticles": 3,
+        "ParticleTime": 1.5,
+        "PDGValues": [1, 2, 3, 4],
+        "MetadataString": "hello",
+        "FinalizeMetadataInt": 10,
+    },
+)
+
+check_metadata(
+    "functional_metadata_old_algorithm.root",
+    {
+        "SimTrackerHits__CellIDEncoding": "M:3,S-1:3,I:9,J:9,K-1:6",
+    },
+)
+
+check_metadata(
+    "functional_metadata_old_algorithm_propagate.root",
+    {
+        "SimTrackerHits__CellIDEncoding": "M:3,S-1:3,I:9,J:9,K-1:6",
+    },
+)
 
 reader = podio.root_io.Reader("eventHeaderConcurrent.root")
 events = reader.get("events")

test/k4FWCoreTest/options/ExampleFunctionalMetadataRead.py

@@ -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.
+#
+
+# This is an example accessing matadata read from input file using MetadataSvc
+
+from Gaudi.Configuration import INFO
+from Configurables import ExampleFunctionalMetadataConsumer
+from k4FWCore import ApplicationMgr, IOSvc
+from Configurables import EventDataSvc
+
+iosvc = IOSvc()
+iosvc.Input = "functional_metadata.root"
+iosvc.Output = "functional_metadata_propagate.root"
+
+consumer = ExampleFunctionalMetadataConsumer("Consumer", InputCollection=["MCParticles"])
+
+ApplicationMgr(
+    TopAlg=[consumer],
+    EvtSel="NONE",
+    EvtMax=10,
+    ExtSvc=[EventDataSvc("EventDataSvc")],
+    OutputLevel=INFO,
+)

test/k4FWCoreTest/options/ExampleFunctionalMetadataReadOldAlgorithm.py

@@ -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.
+#
+
+# This is an example accessing matadata read from input file using MetaDataHandle
+
+from Gaudi.Configuration import INFO
+from Configurables import k4FWCoreTest_cellID_reader
+from k4FWCore import ApplicationMgr, IOSvc
+
+iosvc = IOSvc()
+iosvc.Input = "functional_metadata_old_algorithm.root"
+iosvc.Output = "functional_metadata_old_algorithm_propagate.root"
+
+consumer = k4FWCoreTest_cellID_reader()
+
+ApplicationMgr(
+    TopAlg=[consumer],
+    EvtSel="NONE",
+    EvtMax=10,
+    ExtSvc=[],
+    OutputLevel=INFO,
+    StopOnSignal=True,
+)