Make the new MetadataSvc compatible with DataHandle based algorithms

k4FWCore/include/k4FWCore/MetaDataHandle.h

@@ -19,6 +19,13 @@
 #ifndef K4FWCORE_METADATAHANDLE_H
 #define K4FWCORE_METADATAHANDLE_H
 
+#include <GaudiKernel/Bootstrap.h>
+#include <GaudiKernel/DataHandle.h>
+#include <GaudiKernel/Service.h>
+#include <GaudiKernel/ServiceHandle.h>
+
+#include "MetadataUtils.h"
+#include "k4FWCore/IMetadataSvc.h"
 #include "k4FWCore/PodioDataSvc.h"
 
 template <typename T> class MetaDataHandle {
@@ -95,10 +102,17 @@ template <typename T> std::optional<T> MetaDataHandle<T>::get_optional() const {
 
 //---------------------------------------------------------------------------
 template <typename T> const T MetaDataHandle<T>::get() const {
-  const auto maybeVal = get_optional();
-  if (!maybeVal.has_value()) {
-    throw GaudiException("MetaDataHandle empty handle access",
-                         "MetaDataHandle " + fullDescriptor() + " not (yet?) available", StatusCode::FAILURE);
+  std::optional<T> maybeVal;
+  // DataHandle based algorithms
+  if (m_podio_data_service) {
+    maybeVal = get_optional();
+    if (!maybeVal.has_value()) {
+      throw GaudiException("MetaDataHandle empty handle access",
+                           "MetaDataHandle " + fullDescriptor() + " not (yet?) available", StatusCode::FAILURE);
+    }
+    // Functional algorithms
+  } else {
+    maybeVal = k4FWCore::getParameter<T>(fullDescriptor());
   }
   return maybeVal.value();
 }
@@ -115,13 +129,20 @@ template <typename T> void MetaDataHandle<T>::put(T value) {
                          StatusCode::FAILURE);
   // check whether we are in the proper State
   // put is only allowed in the initalization
-  if (m_podio_data_service->targetFSMState() == Gaudi::StateMachine::RUNNING) {
-    throw GaudiException("MetaDataHandle policy violation", "Put cannot be used during the event loop",
-                         StatusCode::FAILURE);
+
+  std::string full_descriptor = fullDescriptor();
+  // DataHandle based algorithms
+  if (m_podio_data_service) {
+    if (m_podio_data_service->targetFSMState() == Gaudi::StateMachine::RUNNING) {
+      throw GaudiException("MetaDataHandle policy violation", "Put cannot be used during the event loop",
+                           StatusCode::FAILURE);
+    }
+    podio::Frame& frame = m_podio_data_service->getMetaDataFrame();
+    frame.putParameter(full_descriptor, value);
+    // Functional algorithms
+  } else {
+    k4FWCore::putParameter(full_descriptor, value);
   }
-  std::string   full_descriptor = fullDescriptor();
-  podio::Frame& frame           = m_podio_data_service->getMetaDataFrame();
-  frame.putParameter(full_descriptor, value);
 }
 
 //---------------------------------------------------------------------------
@@ -145,7 +166,7 @@ template <typename T> void MetaDataHandle<T>::checkPodioDataSvc() {
   if (cmd.find("genconf") != std::string::npos)
     return;
 
-  if (nullptr == m_podio_data_service) {
+  if (!m_podio_data_service && !Gaudi::svcLocator()->service<IMetadataSvc>("MetadataSvc")) {
     std::cout << "ERROR: MetaDataHandles require the PodioDataSvc" << std::endl;
   }
 }

k4FWCore/include/k4FWCore/MetadataUtils.h

@@ -38,6 +38,16 @@ namespace k4FWCore {
     }
     metadataSvc->put<T>(name, value);
   }
+  /// @brief Save a metadata parameter in the metadata frame. Overload for compatibility
+  /// with the MetadataHandle, don't use!
+  template <typename T> void putParameter(const std::string& name, const T& value) {
+    auto metadataSvc = Gaudi::svcLocator()->service<IMetadataSvc>("MetadataSvc", false);
+    if (!metadataSvc) {
+      std::cout << "MetadataSvc not found" << std::endl;
+      return;
+    }
+    return metadataSvc->put<T>(name, value);
+  }
   /// @brief Get a metadata parameter from the metadata frame
   /// @param name The name of the parameter
   /// @param alg The algorithm that is saving the parameter, typically "this"
@@ -50,6 +60,15 @@ namespace k4FWCore {
     }
     return metadataSvc->get<T>(name);
   }
+  /// @brief Get a metadata parameter from the metadata frame. Overload for compatibility
+  /// with the MetadataHandle, don't use!
+  template <typename T> std::optional<T> getParameter(const std::string& name) {
+    auto metadataSvc = Gaudi::svcLocator()->service<IMetadataSvc>("MetadataSvc", false);
+    if (!metadataSvc) {
+      return std::nullopt;
+    }
+    return metadataSvc->get<T>(name);
+  }
 }  // namespace k4FWCore
 
 #endif  // FWCORE_METADATAUTILS_H

test/k4FWCoreTest/CMakeLists.txt

@@ -136,9 +136,10 @@ 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(FunctionalMetadataOldAlgorithm options/ExampleFunctionalMetadataOldAlgorithm.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")
+set_tests_properties(FunctionalCheckFiles PROPERTIES DEPENDS "FunctionalFile;FunctionalMTFile;FunctionalMultipleFile;FunctionalOutputCommands;FunctionalProducerAbsolutePath;FunctionalTransformerRuntimeEmpty;FunctionalMix;FunctionalMixIOSvc;FunctionalTransformerHist;FunctionalCollectionMerger;FunctionalFilterFile;FunctionalMetadata;FunctionalMetadataOldAlgorithm")
 
 # 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

@@ -175,3 +175,12 @@ def check_events(filename, number):
 ):
     if metadata.get_parameter(key) != value:
         raise RuntimeError(f"Metadata parameter {key} does not match expected value")
+
+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 expected value")

test/k4FWCoreTest/options/ExampleFunctionalMetadataOldAlgorithm.py

@@ -0,0 +1,42 @@
+#
+# 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.
+#
+from Gaudi.Configuration import INFO
+from Configurables import k4FWCoreTest_cellID_writer, k4FWCoreTest_cellID_reader
+from k4FWCore import ApplicationMgr, IOSvc
+
+iosvc = IOSvc()
+iosvc.output = "functional_metadata_old_algorithm.root"
+
+producer = k4FWCoreTest_cellID_writer()
+consumer = k4FWCoreTest_cellID_reader()
+
+
+# out = PodioOutput("out")
+# out.filename = "output_k4test_exampledata_cellid.root"
+# out.outputCommands = ["keep *"]
+
+
+ApplicationMgr(
+    TopAlg=[producer, consumer],
+    EvtSel="NONE",
+    EvtMax=10,
+    ExtSvc=[],
+    OutputLevel=INFO,
+    StopOnSignal=True,
+)