ini.cpp

Go to the documentation of this file.

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "stdafx.h"
#include "debug.h"
#include "ini_type.h"
#include "string_func.h"
#include "fileio_func.h"
#include <fstream>
#ifdef __EMSCRIPTEN__
# include <emscripten.h>
#endif
 
#if (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 199309L) || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 500)
# include <unistd.h>
# include <fcntl.h>
#endif
 
#include <filesystem>
 
#include "safeguards.h"
 
IniFile::IniFile(const IniGroupNameList &list_group_names) : IniLoadFile(list_group_names)
{
}
 
bool IniFile::SaveToDisk(const std::string &filename)
{
  /*
   * First write the configuration to a (temporary) file and then rename
   * that file. This to prevent that when OpenTTD crashes during the save
   * you end up with a truncated configuration file.
   */
  std::string file_new{ filename };
  file_new.append(".new");
 
  std::ofstream os(OTTD2FS(file_new).c_str());
  if (os.fail()) return false;
 
  for (const IniGroup &group : this->groups) {
    os << group.comment << "[" << group.name << "]\n";
    for (const IniItem &item : group.items) {
      os << item.comment;
 
      /* protect item->name with quotes if needed */
      if (item.name.find(' ') != std::string::npos ||
        item.name[0] == '[') {
        os << "\"" << item.name << "\"";
      } else {
        os << item.name;
      }
 
      os << " = " << item.value.value_or("") << "\n";
    }
  }
  os << this->comment;
 
  os.flush();
  os.close();
  if (os.fail()) return false;
 
/*
 * POSIX (and friends) do not guarantee that when a file is closed it is
 * flushed to the disk. So we manually flush it do disk if we have the
 * APIs to do so. We only need to flush the data as the metadata itself
 * (modification date etc.) is not important to us; only the real data is.
 */
#if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
  int f = open(file_new.c_str(), O_RDWR);
  int ret = fdatasync(f);
  close(f);
  if (ret != 0) return false;
#endif
 
  std::error_code ec;
  std::filesystem::rename(OTTD2FS(file_new), OTTD2FS(filename), ec);
  if (ec) {
    Debug(misc, 0, "Renaming {} to {} failed; configuration not saved: {}", file_new, filename, ec.message());
  }
 
#ifdef __EMSCRIPTEN__
  EM_ASM(if (window["openttd_syncfs"]) openttd_syncfs());
#endif
 
  return true;
}
 
/* virtual */ std::optional<FileHandle> IniFile::OpenFile(const std::string &filename, Subdirectory subdir, size_t *size)
{
  /* Open the text file in binary mode to prevent end-of-line translations
   * done by ftell() and friends, as defined by K&R. */
  return FioFOpenFile(filename, "rb", subdir, size);
}
 
/* virtual */ void IniFile::ReportFileError(const char * const pre, const char * const buffer, const char * const post)
{
  ShowInfo("{}{}{}", pre, buffer, post);
}