src/ini.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file ini.cpp Definition of the IniItem class, related to reading/writing '*.ini' files. */
   9
  10 #include "stdafx.h"
  11 #include "debug.h"
  12 #include "ini_type.h"
  13 #include "string_func.h"
  14 #include "fileio_func.h"
  15 #include <fstream>
  16 #ifdef __EMSCRIPTEN__
  17 #       include <emscripten.h>
  18 #endif
  19
  20 #if (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 199309L) || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 500)
  21 # include <unistd.h>
  22 # include <fcntl.h>
  23 #endif
  24
  25 #include <filesystem>
  26
  27 #include "safeguards.h"
  28
  29 /**
  30  * Create a new ini file with given group names.
  31  * @param list_group_names A list with group names that should be loaded as lists instead of variables. @see IGT_LIST
  32  */
  33 IniFile::IniFile(const IniGroupNameList &list_group_names) : IniLoadFile(list_group_names)
  34 {
  35 }
  36
  37 /**
  38  * Save the Ini file's data to the disk.
  39  * @param filename the file to save to.
  40  * @return true if saving succeeded.
  41  */
  42 bool IniFile::SaveToDisk(const std::string &filename)
  43 {
  44         /*
  45          * First write the configuration to a (temporary) file and then rename
  46          * that file. This to prevent that when OpenTTD crashes during the save
  47          * you end up with a truncated configuration file.
  48          */
  49         std::string file_new{ filename };
  50         file_new.append(".new");
  51
  52         std::ofstream os(OTTD2FS(file_new).c_str());
  53         if (os.fail()) return false;
  54
  55         for (const IniGroup &group : this->groups) {
  56                 os << group.comment << "[" << group.name << "]\n";
  57                 for (const IniItem &item : group.items) {
  58                         os << item.comment;
  59
  60                         /* protect item->name with quotes if needed */
  61                         if (item.name.find(' ') != std::string::npos ||
  62                                 item.name[0] == '[') {
  63                                 os << "\"" << item.name << "\"";
  64                         } else {
  65                                 os << item.name;
  66                         }
  67
  68                         os << " = " << item.value.value_or("") << "\n";
  69                 }
  70         }
  71         os << this->comment;
  72
  73         os.flush();
  74         os.close();
  75         if (os.fail()) return false;
  76
  77 /*
  78  * POSIX (and friends) do not guarantee that when a file is closed it is
  79  * flushed to the disk. So we manually flush it do disk if we have the
  80  * APIs to do so. We only need to flush the data as the metadata itself
  81  * (modification date etc.) is not important to us; only the real data is.
  82  */
  83 #if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
  84         int f = open(file_new.c_str(), O_RDWR);
  85         int ret = fdatasync(f);
  86         close(f);
  87         if (ret != 0) return false;
  88 #endif
  89
  90         std::error_code ec;
  91         std::filesystem::rename(OTTD2FS(file_new), OTTD2FS(filename), ec);
  92         if (ec) {
  93                 Debug(misc, 0, "Renaming {} to {} failed; configuration not saved: {}", file_new, filename, ec.message());
  94         }
  95
  96 #ifdef __EMSCRIPTEN__
  97         EM_ASM(if (window["openttd_syncfs"]) openttd_syncfs());
  98 #endif
  99
 100         return true;
 101 }
 102
 103 /* virtual */ std::optional<FileHandle> IniFile::OpenFile(const std::string &filename, Subdirectory subdir, size_t *size)
 104 {
 105         /* Open the text file in binary mode to prevent end-of-line translations
 106          * done by ftell() and friends, as defined by K&R. */
 107         return FioFOpenFile(filename, "rb", subdir, size);
 108 }
 109
 110 /* virtual */ void IniFile::ReportFileError(const char * const pre, const char * const buffer, const char * const post)
 111 {
 112         ShowInfo("{}{}{}", pre, buffer, post);
 113 }