JRootFileWriter.hh

Go to the documentation of this file.

#ifndef __JROOTFILEWRITER__
#define __JROOTFILEWRITER__

#include "TFile.h"

#include "JLang/JObjectOutput.hh"
#include "JLang/JTypeList.hh"
#include "JLang/JNullType.hh"
#include "JLang/JException.hh"
#include "JROOT/JTreeWriterObjectOutput.hh"
#include "JROOT/JTreeParameters.hh"
#include "JROOT/JRootFile.hh"

/**
 * \author mdejong
 */


namespace JROOT {}
namespace JPP { using namespace JROOT; }

namespace JROOT {

  using JLANG::JObjectOutput;
  using JLANG::JAccessibleObjectOutput;
  using JLANG::JTypeList;
  using JLANG::JNullType;


  /**
   * Write object to ROOT directory.
   *
   * \param  dir        pointer to directory
   * \param  object     object
   * \return            true if OK; else false
   */
  template<class T>
  inline bool putObject(TDirectory* dir, const T& object)
  {
    return (dir != NULL && dir->WriteTObject(&object) > 0);
  }


  /**
   * Template definition of ROOT object output.
   */
  template<class T, bool = JTreeParametersAvailable<T>::result>
  class JRootObjectOutput;


  /**
   * Implementation of object output using TDirectory::WriteTObject method.
   *
   * This class implements the JLANG::JObjectOutput interface.
   */
  template<class T>
  class JRootObjectOutput<T,false> :
    public virtual JObjectOutput<T>
  {
  protected:
    /**
     * Default constructor.
     */
    JRootObjectOutput() :
      directory(NULL)
    {}
    

    /**
     * Set directory.
     *
     * \param  dir        pointer to directory
     */
    void SetDirectory(TDirectory* dir)
    {
      this->directory = dir;
    }


    TDirectory* directory;

  public:
    /**
     * Object output.
     *
     * \param  object     object
     * \return            true if OK; else false
     */
    virtual bool put(const T& object) override 
    {
      if (directory != NULL)
        return putObject(directory, object);
      else
        return false;
    }
  };


  /**
   * Implementation of object output using TTree.
   *
   * This class implements the JLANG::JObjectOutput interface.
   */
  template<class T>
  class JRootObjectOutput<T,true> : 
    public JTreeWriterObjectOutput<T>
  {};


  /**
   * Implementation of object output to ROOT file for single data type.
   */
  template<class T>
  class JRootFileObjectOutput :
    public JRootObjectOutput<T>
  {};


  /**
   * Implementation of object output to ROOT file for multiple data types.
   *
   * This class recursively implements the JLANG::JObjectOutput interface
   * for all data types by deriving from:
   *  - JRootFileObjectOutput<JHead_t>; and 
   *  - JRootFileObjectOutput<JTail_t>.
   */
  template<class JHead_t, class JTail_t>
  class JRootFileObjectOutput< JTypeList<JHead_t, JTail_t> > :
    public JObjectOutput< JTypeList<JHead_t, JTail_t> >,
    public JRootFileObjectOutput<JHead_t>,
    public JRootFileObjectOutput<JTail_t>

  {
  protected:
    /**
     * Set directory.
     *
     * \param  dir        pointer to directory
     */
    void SetDirectory(TDirectory* dir)
    {
      JRootFileObjectOutput<JHead_t>::SetDirectory(dir);
      JRootFileObjectOutput<JTail_t>::SetDirectory(dir);
    }
  };


  /**
   * Terminator class of recursive JRootObjectOutput class.
   */
  template<class JHead_t>
  class JRootFileObjectOutput< JTypeList<JHead_t, JNullType> > :
    public JRootFileObjectOutput<JHead_t>
  {};


  /**
   * ROOT file object output.
   *
   * This class implements the JLANG::JAccessibleObjectOutput interface.
   */
  template<class T>
  class JRootFileWriter :
    public JRootFileObjectOutput  <T>,
    public JAccessibleObjectOutput<T>,
    public JRootOutputFile
  {
  public:
    /**
     * Default constructor.
     */
    JRootFileWriter() :
      JRootFileObjectOutput  <T>(),
      JAccessibleObjectOutput<T>()
    {}


    /**
     * Open file.
     *
     * \param  file_name      file name
     */
    virtual void open(const char* file_name) override 
    {
      JRootOutputFile::open(file_name);

      if (is_open()) {
        this->SetDirectory(getFile());
      }
    }
  };
}

#endif