Utility to store received histograms (hierarchical tree structures) from clients (as an event message), with a function to add multiple histogram trees together. More...

#include <HistogramMapping.h>

Public Member Functions
HistogramMapping &	operator= (const HistogramMapping &rhs)=delete
	As this is a heavy object, make sure to not copy.

HistogramMapping &	operator= (HistogramMapping &&rhs)=default
	Moving is allowed.

	HistogramMapping (const HistogramMapping &rhs)=delete
	As this is a heavy object, make sure to not copy.

	HistogramMapping (HistogramMapping &&rhs)=default
	Moving is allowed.

	HistogramMapping ()=default
	Default constructor needed during summation.

	HistogramMapping (std::unique_ptr< Belle2::EvtMessage > msg)
	Constructor via a received event message by deserializing the histograms.

void	operator+= (const HistogramMapping &rhs)
	Add another histogramm tree instance by merging all histograms with the same name.

void	write () const
	Write out all stored histograms in the currently selected ROOT gDirectory.

void	clear ()
	Clear all histograms in the internal map also deleting the pointers.

void	printMe () const
	Debug function to print out the content as into messages.

std::unique_ptr< Belle2::EvtMessage >	toMessage () const
	Construct an EvtMessage by serializing the content of the internal histogram storage. Will not invalidate the histograms.

bool	empty () const
	Check if there are no stored histograms.

Private Attributes
std::map< std::string, std::unique_ptr< TH1 > >	m_histograms
	Internal storage of the histograms in the form name -> unique TH1 pointer.

Detailed Description

Utility to store received histograms (hierarchical tree structures) from clients (as an event message), with a function to add multiple histogram trees together.

Can be converted back into a single event message and is used in the histogram server for merging the received histogram messages. Internally, the tree structure is stored as a mapping name -> TH1 (unique) pointer, where folder structure is mapped via "/" in the name.

Definition at line 30 of file HistogramMapping.h.

Constructor & Destructor Documentation

◆ HistogramMapping()

HistogramMapping ( std::unique_ptr< Belle2::EvtMessage > msg )

explicit

Constructor via a received event message by deserializing the histograms.

Definition at line 19 of file HistogramMapping.cc.

{
  m_histograms.clear();
 
  Belle2::MsgHandler msgHandler;
  std::vector<TObject*> objects;
  std::vector<std::string> names;
  msgHandler.decode_msg(msg.get(), objects, names);
 
  B2ASSERT("Objects and names need to align", names.size() == objects.size());
 
  for (const auto& keyValue : boost::combine(names, objects)) {
    std::string key;
    TObject* object;
    boost::tie(key, object) = keyValue;
 
    TH1* histogram = dynamic_cast<TH1*>(object);
    if (histogram == nullptr) {
      B2WARNING("Object " << key << " is not a histogram!");
      continue;
    }
 
    m_histograms.insert({key, std::unique_ptr<TH1>(histogram)});
    m_histograms[key]->SetName(key.c_str());
  }
}

Member Function Documentation

◆ clear()

void clear ( )

Clear all histograms in the internal map also deleting the pointers.

Definition at line 71 of file HistogramMapping.cc.

{
  m_histograms.clear();
}

◆ empty()

bool empty ( ) const

Check if there are no stored histograms.

Definition at line 76 of file HistogramMapping.cc.

{
  return m_histograms.empty();
}

◆ operator+=()

void operator+= ( const HistogramMapping & rhs )

Add another histogramm tree instance by merging all histograms with the same name.

Definition at line 46 of file HistogramMapping.cc.

{
  for (auto& keyValue : rhs.m_histograms) {
    const auto& key = keyValue.first;
    const auto& histogram = keyValue.second;
 
    auto lhsIterator = m_histograms.find(key);
    if (lhsIterator == m_histograms.end()) {
      B2DEBUG(100, "Creating new histogram with name " << key << ".");
      auto* copiedHistogram = dynamic_cast<TH1*>(histogram->Clone());
      m_histograms.insert({key, std::unique_ptr<TH1>(copiedHistogram)});
    } else {
      m_histograms[key]->Add(histogram.get());
    }
  }
}

◆ printMe()

void printMe ( ) const

Debug function to print out the content as into messages.

Definition at line 81 of file HistogramMapping.cc.

{
  for (const auto& [key, histogram] : m_histograms) {
    B2INFO(key << ": " << histogram->GetName() << " -> " << histogram->GetEntries());
  }
}

◆ toMessage()

std::unique_ptr< Belle2::EvtMessage > toMessage ( ) const

Construct an EvtMessage by serializing the content of the internal histogram storage. Will not invalidate the histograms.

Definition at line 88 of file HistogramMapping.cc.

{
  Belle2::MsgHandler msgHandler;
 
  int objectCounter = 0;
  for (const auto& [key, histogram] : m_histograms) {
    msgHandler.add(histogram.get(), key);
    objectCounter++;
  }
 
  std::unique_ptr<Belle2::EvtMessage> msg(msgHandler.encode_msg(Belle2::ERecordType::MSG_EVENT));
  (msg->header())->reserved[0] = 0;
  (msg->header())->reserved[1] = objectCounter;
 
  return msg;
}

◆ write()

void write ( ) const

Write out all stored histograms in the currently selected ROOT gDirectory.

Definition at line 63 of file HistogramMapping.cc.

{
  for (const auto& [_, histogram] : m_histograms) {
    histogram->SetDirectory(gDirectory);
    histogram->Write();
  }
}

Member Data Documentation

◆ m_histograms

std::map<std::string, std::unique_ptr<TH1> > m_histograms

private

Internal storage of the histograms in the form name -> unique TH1 pointer.

Definition at line 61 of file HistogramMapping.h.

The documentation for this class was generated from the following files:

daq/hbasf2/utils/include/HistogramMapping.h
daq/hbasf2/utils/src/HistogramMapping.cc

Public Member Functions

Private Attributes