Make SIOReader follow the same interface as ROOTReader

Now no longer owns the blocks it reads, but instead creates them for every event and then passes on the ownership to the EventStore
AIDASoft · Sep 16, 2020 · 5c0b5bd · 5c0b5bd
1 parent ce4fc3b
commit 5c0b5bd
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Showing 3 changed files with 39 additions and 26 deletions.
diff --git a/include/podio/SIOReader.h b/include/podio/SIOReader.h
@@ -53,7 +53,7 @@ namespace podio {
     CollectionBase* readCollection(const std::string& name) override final;
 
     /// read event meta data for current event
-    GenericParameters* readEventMetaData() override final { return m_eventMetaData->metadata; }
+    GenericParameters* readEventMetaData() override final;
 
     /// read the collection meta data
     std::map<int,GenericParameters>* readCollectionMetaData() override final;
@@ -64,11 +64,14 @@ namespace podio {
   private:
     void readCollectionIDTable();
     void readMetaDataRecord(std::shared_ptr<SIONumberedMetaDataBlock> mdBlock);
+    void createBlocks();
 
     typedef std::pair<CollectionBase*, std::string> Input;
     std::vector<Input> m_inputs;
     CollectionIDTable* m_table{nullptr}; // will be owned by the EventStore
     int m_eventNumber{0};
+    int m_lastEventRead{-1};
+    std::vector<std::string> m_typeNames;
 
     std::shared_ptr<SIOEventMetaDataBlock> m_eventMetaData{};
     std::shared_ptr<SIONumberedMetaDataBlock> m_runMetaData{};

diff --git a/src/SIOReader.cc b/src/SIOReader.cc
@@ -18,13 +18,14 @@ namespace podio {
     m_runMetaData(std::make_shared<SIONumberedMetaDataBlock>("RunMetaData")),
     m_collectionMetaData(std::make_shared<SIONumberedMetaDataBlock>("CollectionMetaData"))
   {
-    // make sure that the first block is EventMetaData as it is also the first
-    // during wrting
-    m_blocks.push_back(m_eventMetaData);
     auto& libLoader = SIOBlockLibraryLoader::instance();
   }
 
   CollectionBase* SIOReader::readCollection(const std::string& name) {
+    if (m_lastEventRead != m_eventNumber) {
+      readEvent();
+    }
+
     auto p = std::find_if(begin(m_inputs), end(m_inputs),
                           [&name](const SIOReader::Input& t){ return t.second == name;});
 
@@ -56,6 +57,12 @@ namespace podio {
     return m_runMetaData->data;
   }
 
+  podio::GenericParameters* SIOReader::readEventMetaData() {
+    if (m_lastEventRead != m_eventNumber) {
+      readEvent();
+    }
+    return m_eventMetaData->metadata;
+  }
 
   void SIOReader::openFile(const std::string& filename){
     m_stream.open( filename , std::ios::binary ) ;
@@ -68,7 +75,9 @@ namespace podio {
   }
 
   void SIOReader::readEvent(){
-    m_eventMetaData->metadata = new GenericParameters(); // will be managed by EventStore (?)
+    // recreate the blocks, since the contents are owned and managed by the
+    // EventStore
+    createBlocks();
 
     // skip possible intermediate records that are not event data
     sio::api::go_to_record(m_stream, "event_record");
@@ -80,12 +89,13 @@ namespace podio {
     m_unc_buffer.resize( rec_info._uncompressed_length ) ;
     sio::zlib_compression compressor ;
     compressor.uncompress( m_rec_buffer.span(), m_unc_buffer ) ;
-
     sio::api::read_blocks( m_unc_buffer.span(), m_blocks ) ;
 
     for (auto& [collection, name] : m_inputs) {
       collection->setID(m_table->collectionID(name));
     }
+
+    m_lastEventRead = m_eventNumber;
   }
 
   bool SIOReader::isValid() const {
@@ -98,10 +108,24 @@ namespace podio {
     // TODO: who deletes the buffers?
   }
 
- void SIOReader::endOfEvent() {
-   ++m_eventNumber;
-//   m_inputs.clear();
- }
+  void SIOReader::endOfEvent() {
+    ++m_eventNumber;
+    m_blocks.clear();
+    m_inputs.clear();
+  }
+
+  void SIOReader::createBlocks() {
+    // make sure that the first block is EventMetaData as it is also the first
+    // during wrting
+    m_eventMetaData->metadata = new GenericParameters(); // will be managed by EventStore (?)
+    m_blocks.push_back(m_eventMetaData);
+
+    for (size_t i = 0; i < m_typeNames.size(); ++i) {
+      auto blk = podio::SIOBlockFactory::instance().createBlock(m_typeNames[i], m_table->names()[i]);
+      m_blocks.push_back(blk);
+      m_inputs.emplace_back(blk->getCollection(), m_table->names()[i]);
+    }
+  }
 
   void SIOReader::readCollectionIDTable() {
     sio::record_info rec_info;
@@ -118,14 +142,7 @@ namespace podio {
 
     auto* idTableBlock = static_cast<SIOCollectionIDTableBlock*>(blocks[0].get());
     m_table = idTableBlock->getTable();
-    const auto& typeNames = idTableBlock->getTypeNames();
-
-    for (size_t i = 0; i < typeNames.size(); ++i) {
-      auto blk = podio::SIOBlockFactory::instance().createBlock(typeNames[i], m_table->names()[i]);
-      m_blocks.push_back(blk);
-      m_inputs.emplace_back(std::make_pair(blk->getCollection(), m_table->names()[i]));
-    }
-
+    m_typeNames = idTableBlock->getTypeNames();
   }
 
   void SIOReader::readMetaDataRecord(std::shared_ptr<SIONumberedMetaDataBlock> mdBlock) {

diff --git a/tests/read_sio.cpp b/tests/read_sio.cpp
@@ -15,16 +15,9 @@ int main(){
       if(i%1000==0)
         std::cout<<"reading event "<<i<<std::endl;
 
-      reader.readEvent() ;
-
       processEvent(store, true, i);
-
-      // only clear collections for re-use
-      store.clearCollections();
-      store.clearCaches(); // Would be done in EventStore::clear
-      // store.clear();    // However, this would delete the collections as well ...
+      store.clear();
       reader.endOfEvent();
-
     }
   }
   catch( sio::exception &e ) {