Method saveObject

src/app/crash/write_document.cpp:161–202

  template<typename T>
  void saveObject(const char* prefix, T* obj, void (Writer::*writeMember)(std::ofstream&, T*)) {
    if (!obj->version())
      obj->incrementVersion();

    ObjVersions& versions = m_objVersions[obj->id()];
    if (versions.newer() == obj->version())
      return;

    std::string fn = prefix;
    fn.push_back('-');
    fn += base::convert_to<std::string>(obj->id());

    std::string fullfn = base::join_path(m_dir, fn);
    std::string oldfn = fullfn + "." + base::convert_to<std::string>(versions.older());
    fullfn += "." + base::convert_to<std::string>(obj->version());

    std::ofstream s(FSTREAM_PATH(fullfn), std::ofstream::binary);
    write32(s, 0);                // Leave a room for the magic number
    (this->*writeMember)(s, obj); // Write the object

    // Flush all data. In this way we ensure that the magic number is
    // the last thing being written in the file.
    s.flush();

    // Write the magic number
    s.seekp(0);
    write32(s, MAGIC_NUMBER);

    // Remove the older version
    try {
      if (versions.older() && base::is_file(oldfn))
        base::delete_file(oldfn);
    }
    catch (const std::exception&) {
      TRACE(" - Cannot delete %s #%d v%d\n", prefix, obj->id(), versions.older());
    }

    // Rotate versions and add the latest one
    versions.rotateRevisions(obj->version());

    TRACE(" - Saved %s #%d v%d\n", prefix, obj->id(), obj->version());
  }

  std::string m_dir;
  app::Document* m_doc;