Allow calling finish() multiple times, with no effect after the first (#798)

* Allow calling finish() multiple times, with no effect after the first

* Move the check to finish() also for SIOWriter

---------

Co-authored-by: jmcarcell <jmcarcell@users.noreply.github.com>

Author: jmcarcell

src/RNTupleWriter.cc

@@ -28,9 +28,7 @@ RNTupleWriter::RNTupleWriter(const std::string& filename) :
 }
 
 RNTupleWriter::~RNTupleWriter() {
-  if (!m_finished) {
-    finish();
-  }
+  finish();
 }
 
 template <typename T>
@@ -235,6 +233,9 @@ RNTupleWriter::CategoryInfo& RNTupleWriter::getCategoryInfo(const std::string& c
 }
 
 void RNTupleWriter::finish() {
+  if (m_finished) {
+    return;
+  }
   auto metadata = root_compat::RNTupleModel::Create();
 
   const auto podioVersion = podio::version::build_version;

src/ROOTWriter.cc

@@ -17,9 +17,7 @@ ROOTWriter::ROOTWriter(const std::string& filename) {
 }
 
 ROOTWriter::~ROOTWriter() {
-  if (!m_finished) {
-    finish();
-  }
+  finish();
 }
 
 void ROOTWriter::writeFrame(const podio::Frame& frame, const std::string& category) {
@@ -168,6 +166,9 @@ void ROOTWriter::resetBranches(CategoryInfo& categoryInfo,
 }
 
 void ROOTWriter::finish() {
+  if (m_finished) {
+    return;
+  }
   auto* metaTree = new TTree(root_utils::metaTreeName, "metadata tree for podio I/O functionality");
   metaTree->SetDirectory(m_file.get());
 

src/SIOWriter.cc

@@ -25,9 +25,7 @@ SIOWriter::SIOWriter(const std::string& filename) {
 }
 
 SIOWriter::~SIOWriter() {
-  if (!m_finished) {
-    finish();
-  }
+  finish();
 }
 
 void SIOWriter::writeFrame(const podio::Frame& frame, const std::string& category) {
@@ -55,6 +53,9 @@ void SIOWriter::writeFrame(const podio::Frame& frame, const std::string& categor
 }
 
 void SIOWriter::finish() {
+  if (m_finished) {
+    return;
+  }
   auto edmDefMap = std::make_shared<podio::SIOMapBlock<std::string, std::string>>(
       m_datamodelCollector.getDatamodelDefinitionsToWrite());