Add an EmptyEventCreator data source for testing and examples

source/include/marlin/EmptyEventCreator.h

@@ -0,0 +1,38 @@
+#ifndef EmptyEventCreator_h
+#define EmptyEventCreator_h 1
+
+#include "marlin/DataSourceProcessor.h"
+
+namespace marlin {
+
+/** Creates empty LCIO Events that can then be populated by other processors.
+ *  Useful for testing purposes and examples, where having a dedicated input
+ *  just for "getting the event loop going" is not always practical. This needs
+ *  to be the first active processor and additionally requires that there are no
+ *  LCIO input collections present (i.e. make sure to not set the
+ *  LCIOInputFiles parameter).
+ *
+ *  <h4>Input</h4>
+ *  None
+ *
+ *  <h4>Output</4>
+ *  an empty LCEvent
+ *
+ *  @author: T. Madlener, DESY
+ */
+class EmptyEventCreator : public DataSourceProcessor {
+public:
+  EmptyEventCreator();
+
+  marlin::Processor* newProcessor() override { return new EmptyEventCreator; }
+
+  void readDataSource(int numEvents) override;
+  void init() override;
+
+private:
+  int m_eventNumber{0};
+};
+
+}
+
+#endif

source/src/EmptyEventCreator.cc

@@ -0,0 +1,40 @@
+#include "marlin/EmptyEventCreator.h"
+
+#include "marlin/ProcessorMgr.h"
+
+#include "IMPL/LCEventImpl.h"
+#include "IMPL/LCRunHeaderImpl.h"
+
+#include <memory>
+
+namespace marlin {
+EmptyEventCreator anEmptyEventCreator;
+
+EmptyEventCreator::EmptyEventCreator() : DataSourceProcessor("EmptyEventCreator") {
+  _description = "Creates empty events that can be filled by other processors";
+}
+
+void EmptyEventCreator::init() {
+  printParameters();  // Do we need to do anything at all?
+}
+
+void EmptyEventCreator::readDataSource(int numEvents) {
+  while (m_eventNumber < numEvents) {
+    if (isFirstEvent()) {
+      auto* runHeader = new LCRunHeaderImpl; // who cleans this up?
+      runHeader->setDescription("Empty events produced to be filled later");
+      runHeader->setRunNumber(0);
+
+      ProcessorMgr::instance()->processRunHeader(runHeader);
+      _isFirstEvent = false;
+    }
+
+    auto evt = std::make_unique<LCEventImpl>();
+    evt->setRunNumber(0);
+    evt->setEventNumber(m_eventNumber++);
+
+    ProcessorMgr::instance()->processEvent(evt.get());
+  }
+}
+
+} // namespace marlin

test/marlintest/include/TestEmptyEventCreator.h

@@ -0,0 +1,28 @@
+#ifndef TestEmptyEventCreator_h
+#define TestEmptyEventCreator_h 1
+
+#include "marlin/Processor.h"
+
+#include "lcio.h"
+
+/** Test processor to check that the EmptyEventCreator data source produces the
+ * expected empty events
+ */
+class TestEmptyEventCreator : public marlin::Processor {
+
+public:
+  TestEmptyEventCreator *newProcessor() override {
+    return new TestEmptyEventCreator;
+  }
+
+  TestEmptyEventCreator();
+
+  void processRunHeader(lcio::LCRunHeader *run) override;
+
+  void processEvent(lcio::LCEvent *evt) override;
+
+private:
+  int m_expectedEvt{0};
+};
+
+#endif

test/marlintest/src/TestEmptyEventCreator.cc

@@ -0,0 +1,59 @@
+#include "TestEmptyEventCreator.h"
+
+#include <string>
+#include <vector>
+
+TestEmptyEventCreator aTestEmptyEventCreator;
+
+TestEmptyEventCreator::TestEmptyEventCreator()
+    : marlin::Processor("TestEmptyEventCreator") {
+  _description = "Processor to test whether the EmptyEventCreator data source "
+                 "works as expected";
+}
+
+void TestEmptyEventCreator::processRunHeader(lcio::LCRunHeader *run) {
+  if (run->getRunNumber() != 0) {
+    throw lcio::Exception("Run number from EmptyEventCreator is not 0 (" +
+                          std::to_string(run->getRunNumber()) + ")");
+  }
+}
+
+void TestEmptyEventCreator::processEvent(lcio::LCEvent *evt) {
+  if (evt->getEventNumber() != m_expectedEvt) {
+    throw lcio::Exception(
+        "Event number from EmptyEventCreator is not as expected (expected: " +
+        std::to_string(m_expectedEvt) +
+        ", actual: " + std::to_string(evt->getEventNumber()) + ")");
+  }
+
+  if (!evt->getCollectionNames()->empty()) {
+    throw lcio::Exception(
+        "EmptyEventCreator should create empty events, but LCEvent contains " +
+        std::to_string(evt->getCollectionNames()->size()) + " collections");
+  }
+
+  const auto &params = evt->getParameters();
+
+  std::vector<std::string> keys;
+  params.getIntKeys(keys);
+  if (!keys.empty()) {
+    throw lcio::Exception(
+        "EmptyEventCreator should create empty events, but has int parameters");
+  }
+  keys.clear();
+
+  params.getFloatKeys(keys);
+  if (!keys.empty()) {
+    throw lcio::Exception("EmptyEventCreator should create empty events, but "
+                          "has float parameters");
+  }
+  keys.clear();
+
+  params.getStringKeys(keys);
+  if (!keys.empty()) {
+    throw lcio::Exception("EmptyEventCreator should create empty events, but "
+                          "has string parameters");
+  }
+
+  m_expectedEvt++;
+}

test/testmarlin/CMakeLists.txt

@@ -81,3 +81,17 @@ SET_TESTS_PROPERTIES( t_parse_steering_comments PROPERTIES PASS_REGULAR_EXPRESSI
 SET_TESTS_PROPERTIES( t_parse_steering_comments PROPERTIES PASS_REGULAR_EXPRESSION "ONLY {}")
 SET_TESTS_PROPERTIES( t_parse_steering_comments PROPERTIES PASS_REGULAR_EXPRESSION "TRAILING {Content, first}")
 SET_TESTS_PROPERTIES( t_parse_steering_comments PROPERTIES PASS_REGULAR_EXPRESSION "EXPLICIT {Hello, It, Is, Me}")
+
+#---------------------------------------------------------------------------------------
+SET( MARLIN_STEERING_FILE empty_event_creator.xml )
+SET( MARLIN_INPUT_FILES
+  ${CMAKE_CURRENT_SOURCE_DIR}/${MARLIN_STEERING_FILE}
+  ${CMAKE_CURRENT_SOURCE_DIR}/gear_simjob.xml
+  ${CMAKE_CURRENT_SOURCE_DIR}/simjob.slcio
+)
+
+CONFIGURE_FILE( runmarlin.cmake.in empty_event_creator.cmake @ONLY )
+ADD_TEST( t_empty_event_creator "${CMAKE_COMMAND}" -P empty_event_creator.cmake )
+
+SET_TESTS_PROPERTIES( t_empty_event_creator PROPERTIES FAIL_REGULAR_EXPRESSION "Marlin will have to be terminated, sorry." )
+#---------------------------------------------------------------------------------------

test/testmarlin/empty_event_creator.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<marlin xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://ilcsoft.desy.de/marlin/marlin.xsd">
+
+  <execute>
+    <processor name="EmptyEventCreator"/>
+    <processor name="MyTestEmptyEventCreator"/>
+  </execute>
+
+  <global>
+    <parameter name="MaxRecordNumber" value="10"/>
+  </global>
+
+  <processor name="EmptyEventCreator" type="EmptyEventCreator"/>
+
+  <processor name="MyTestEmptyEventCreator" type="TestEmptyEventCreator">
+    <!--Processor to test whether the EmptyEventCreator data source works as expected-->
+    <!--verbosity level of this processor ("DEBUG0-4,MESSAGE0-4,WARNING0-4,ERROR0-4,SILENT")-->
+    <!--parameter name="Verbosity" type="string">DEBUG </parameter-->
+  </processor>
+
+</marlin>