[QC-428] Standalone Data Sampling executable (#4574)

knopers8 · web-flow · commit 7a4812bee28f · 2020-10-19T11:10:40.000+02:00
diff --git a/Utilities/DataSampling/CMakeLists.txt b/Utilities/DataSampling/CMakeLists.txt
@@ -61,6 +61,11 @@ endforeach()
 
 o2_data_file(COPY etc/exampleDataSamplingConfig.json DESTINATION etc)
 
+o2_add_dpl_workflow(standalone
+  SOURCES src/dataSamplingStandalone.cxx
+  COMPONENT_NAME DataSampling
+  PUBLIC_LINK_LIBRARIES O2::DataSampling)
+
 o2_add_dpl_workflow(datasampling-pod-and-root
   SOURCES test/dataSamplingPodAndRoot.cxx
   COMPONENT_NAME DataSampling
diff --git a/Utilities/DataSampling/README.md b/Utilities/DataSampling/README.md
@@ -24,7 +24,11 @@ Data Sampling provides possibility to sample data in DPL workflows, basing on ce
 
 ### Usage
 
-To use Data Sampling in a DPL workflow insert following lines to your code:
+One can use Data Sampling either by merging the standalone Data Sampling workflow with other DPL workflows:
+```bash
+o2-workflow-abc | o2-datasampling-standalone --config json://path/to/config.json | o2-workflow-xyz
+```
+...or by incorporating the code below into a DPL workflow which needs sampling:
 ```cpp
 #include "DataSampling/DataSampling.h"
 using namespace o2::framework;
diff --git a/Utilities/DataSampling/src/dataSamplingStandalone.cxx b/Utilities/DataSampling/src/dataSamplingStandalone.cxx
@@ -0,0 +1,45 @@
+// Copyright CERN and copyright holders of ALICE O2. This software is
+// distributed under the terms of the GNU General Public License v3 (GPL
+// Version 3), copied verbatim in the file "COPYING".
+//
+// See http://alice-o2.web.cern.ch/license for full licensing information.
+//
+// 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.
+
+#include "Framework/ConfigParamSpec.h"
+#include "DataSampling/DataSampling.h"
+#include "Framework/CompletionPolicyHelpers.h"
+#include <vector>
+
+using namespace o2::framework;
+using namespace o2::utilities;
+
+void customize(std::vector<CompletionPolicy>& policies)
+{
+  DataSampling::CustomizeInfrastructure(policies);
+}
+
+void customize(std::vector<ChannelConfigurationPolicy>& policies)
+{
+  DataSampling::CustomizeInfrastructure(policies);
+}
+
+void customize(std::vector<ConfigParamSpec>& workflowOptions)
+{
+  workflowOptions.push_back(ConfigParamSpec{"config", VariantType::String, "", {"path to the Data Sampling configuration file"}});
+  workflowOptions.push_back(ConfigParamSpec{"dispatchers", VariantType::Int, 1, {"amount of parallel Dispatchers"}});
+}
+
+#include "Framework/runDataProcessing.h"
+
+WorkflowSpec defineDataProcessing(ConfigContext const& config)
+{
+  auto configurationPath = config.options().get<std::string>("config");
+  auto numberOfDispatchers = config.options().get<int>("dispatchers");
+
+  WorkflowSpec specs;
+  DataSampling::GenerateInfrastructure(specs, configurationPath, numberOfDispatchers);
+  return specs;
+}
