TFileDirectory.h

Go to the documentation of this file.

#ifndef art_Framework_Services_Optional_TFileDirectory_h
#define art_Framework_Services_Optional_TFileDirectory_h

/* class TFileDirectory
 *
 * Original author: Luca Lista, INFN
 *
 */

#include "art/Framework/Services/Optional/detail/RootDirectorySentry.h"

#include "TDirectory.h"

class TFile;
class TGraph;

#include <functional>
#include <map>
#include <string>
#include <utility>

namespace art {

  class TFileDirectory {
  public:
    virtual ~TFileDirectory() = default;

    /// make new ROOT object of type T, using constructor parameters
    /// args. It will be made in the 'current directory', as
    /// established with a call to 'cd'.
    template <typename T, typename... ARGS>
    T* make(ARGS... args) const;

    /// make and register a new ROOT object of type T, giving it the
    /// specified name and title, using constructor parameters
    /// 'args'. The type must be registerable, and must support naming
    /// and titling.
    template <typename T, typename... ARGS>
    T* makeAndRegister(char const* name, char const* title, ARGS... args) const;

    template <typename T, typename... ARGS>
    T* makeAndRegister(std::string const& name,
                       std::string const& title,
                       ARGS... args) const;

    /// Create a new TFileDirectory, sharing the same TFile as this
    /// one, but with an additional 'dir', and with 'path' being the
    /// fullPath() of this one.
    TFileDirectory mkdir(std::string const& dir, std::string const& descr = "");

  protected:
    using Callback_t = std::function<void()>;

    /// Create a new TFileDirectory object.
    TFileDirectory(std::string const& dir,
                   std::string const& descr,
                   TFile* file,
                   std::string const& path);

    void invokeCallbacks();
    void registerCallback(Callback_t);

    /// Return the full pathname of the current directory, formed from
    /// appending 'dir' to the end of 'path'.
    std::string fullPath() const;

    TFile* file_;
    std::string dir_;
    std::string descr_;
    bool requireCallback_{false};

  private:
    std::string path_;
    /// Make the current directory be the one implied by the state of
    /// this TFileDirectory.
    void cd() const;
    std::map<std::string, std::vector<Callback_t>> callbacks_{};
  };

  template <typename T, typename... ARGS>
  T*
  TFileDirectory::make(ARGS... args) const
  {
    detail::RootDirectorySentry sentry;
    cd();
    return new T(args...);
  }

  template <typename T, typename... ARGS>
  T*
  TFileDirectory::makeAndRegister(char const* name,
                                  char const* title,
                                  ARGS... args) const
  {
    detail::RootDirectorySentry sentry;
    cd();
    T* p = new T(args...);
    p->SetName(name);
    p->SetTitle(title);
    gDirectory->Append(p);
    return p;
  }

  template <typename T, typename... ARGS>
  T*
  TFileDirectory::makeAndRegister(std::string const& name,
                                  std::string const& title,
                                  ARGS... args) const
  {
    return makeAndRegister(name.c_str(), title.c_str(), args...);
  }
}

#endif /* art_Framework_Services_Optional_TFileDirectory_h */

/// emacs configuration

/// Local Variables: -
/// mode: c++ -
/// c-basic-offset: 2 -
/// indent-tabs-mode: nil -
/// End: -