Use filesystem of C++17

meson.build

@@ -170,13 +170,14 @@ includes += include_directories('src')
 
 deps += dependency('threads')
 
+
 #############################################################################
 ## Platform specific files
 ############################################################################
-if host_machine.system() == 'windows'
-  files += 'src/utils/filesystem.win32.cc'
+if host_machine.system() == 'android'
+  files += 'src/utils/filesystem.android.cc'
 else
-  files += 'src/utils/filesystem.posix.cc'
+  files += 'src/utils/filesystem.cc'
 endif
 
 #############################################################################
@@ -590,4 +591,4 @@ if get_option('python_bindings')
     [py_files + files],
     include_directories: [includes],
     dependencies: [cpython] + deps)
-endif
+endif

src/utils/filesystem.posix.cc → src/utils/filesystem.android.cc

@@ -77,47 +77,31 @@ time_t GetFileTime(const std::string& filename) {
   if (stat(filename.c_str(), &s) < 0) {
     throw Exception("Cannot stat file: " + filename);
   }
-#ifdef __APPLE__
-  return s.st_mtimespec.tv_sec;
-#else
   return s.st_mtim.tv_sec;
-#endif
 }
 
 std::string GetUserCacheDirectory() {
-#ifdef __APPLE__
-  constexpr auto kLocalDir = "Library/Caches/";
-#else
   constexpr auto kLocalDir = ".cache/";
   const char *xdg_cache_home = std::getenv("XDG_CACHE_HOME");
   if (xdg_cache_home != NULL) return std::string(xdg_cache_home) + "/";
-#endif
   const char *home = std::getenv("HOME");
   if (home == NULL) return std::string();
   return std::string(home) + "/" + kLocalDir;
 }
 
 std::string GetUserConfigDirectory() {
-#ifdef __APPLE__
-  constexpr auto kLocalDir = "Library/Preferences/";
-#else
   constexpr auto kLocalDir = ".config/";
   const char *xdg_config_home = std::getenv("XDG_CONFIG_HOME");
   if (xdg_config_home != NULL) return std::string(xdg_config_home) + "/";
-#endif
   const char *home = std::getenv("HOME");
   if (home == NULL) return std::string();
   return std::string(home) + "/" + kLocalDir;
 }
 
 std::string GetUserDataDirectory() {
-#ifdef __APPLE__
-  constexpr auto kLocalDir = "Library/";
-#else
   constexpr auto kLocalDir = ".local/share/";
   const char *xdg_data_home = std::getenv("XDG_DATA_HOME");
   if (xdg_data_home != NULL) return std::string(xdg_data_home) + "/";
-#endif
   const char *home = std::getenv("HOME");
   if (home == NULL) return std::string();
   return std::string(home) + "/" + kLocalDir;

src/utils/filesystem.cc

@@ -0,0 +1,135 @@
+/*
+  This file is part of Leela Chess Zero.
+  Copyright (C) 2018-2019 The LCZero Authors
+
+  Leela Chess 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, either version 3 of the License, or
+  (at your option) any later version.
+
+  Leela Chess 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 Leela Chess.  If not, see <http://www.gnu.org/licenses/>.
+
+  Additional permission under GNU GPL version 3 section 7
+
+  If you modify this Program, or any covered work, by linking or
+  combining it with NVIDIA Corporation's libraries from the NVIDIA CUDA
+  Toolkit and the NVIDIA CUDA Deep Neural Network library (or a
+  modified version of those libraries), containing parts covered by the
+  terms of the respective license agreement, the licensors of this
+  Program grant you additional permission to convey the resulting work.
+*/
+
+#include "utils/exception.h"
+#include "utils/filesystem.h"
+
+#if __has_include(<filesystem>)
+ #include <filesystem>
+#else
+ #include <experimental/filesystem>
+ // This works for the compilers we care about.
+ namespace std {
+  namespace filesystem = experimental::filesystem;
+ }
+#endif
+
+namespace lczero {
+
+void CreateDirectory(const std::string& path) {
+  try {
+    std::filesystem::create_directory(path);
+  } catch(std::filesystem::filesystem_error& e) {
+    throw Exception("Cannot create directory: " + path);
+  }
+}
+
+std::vector<std::string> GetFileList(const std::string& directory) {
+  std::vector<std::string> result;
+  try {
+    const std::filesystem::path p(directory);
+    if (std::filesystem::exists(p)) {
+      for (const auto & entry : std::filesystem::directory_iterator(directory)) {
+        if (!std::filesystem::is_symlink(entry.path())) {
+          result.push_back(entry.path().filename());
+        }
+      }
+    }
+  } catch(std::filesystem::filesystem_error& e) {}
+  return result;
+}
+
+uint64_t GetFileSize(const std::string& filename) {
+  try {
+    return static_cast<uint64_t>(std::filesystem::file_size(filename));
+  } catch(std::filesystem::filesystem_error&) {}
+  return 0;
+}
+
+time_t GetFileTime(const std::string& filename) {
+  try {
+    std::filesystem::path p(filename);
+    auto ftime = std::filesystem::last_write_time(p);
+    return decltype(ftime)::clock::to_time_t(ftime);
+  } catch(std::filesystem::filesystem_error& e) {
+    CERR << "GetFileTime Exception: " << e.what();
+  }
+  return 0;
+}
+
+std::string GetUserCacheDirectory() {
+#ifdef _WIN32
+    return "";
+#else
+#ifdef __APPLE__
+  constexpr auto kLocalDir = "Library/Caches/";
+#else
+  constexpr auto kLocalDir = ".cache/";
+  const char *xdg_cache_home = std::getenv("XDG_CACHE_HOME");
+  if (xdg_cache_home != NULL) return std::string(xdg_cache_home) + "/";
+#endif
+  const char *home = std::getenv("HOME");
+  if (home == NULL) return std::string();
+  return std::string(home) + "/" + kLocalDir;
+#endif
+}
+
+std::string GetUserConfigDirectory() {
+#ifdef _WIN32
+    return "";
+#else
+#ifdef __APPLE__
+  constexpr auto kLocalDir = "Library/Preferences/";
+#else
+  constexpr auto kLocalDir = ".config/";
+  const char *xdg_config_home = std::getenv("XDG_CONFIG_HOME");
+  if (xdg_config_home != NULL) return std::string(xdg_config_home) + "/";
+#endif
+  const char *home = std::getenv("HOME");
+  if (home == NULL) return std::string();
+  return std::string(home) + "/" + kLocalDir;
+#endif
+}
+
+std::string GetUserDataDirectory() {
+#ifdef _WIN32
+    return "";
+#else
+#ifdef __APPLE__
+  constexpr auto kLocalDir = "Library/";
+#else
+  constexpr auto kLocalDir = ".local/share/";
+  const char *xdg_data_home = std::getenv("XDG_DATA_HOME");
+  if (xdg_data_home != NULL) return std::string(xdg_data_home) + "/";
+#endif
+  const char *home = std::getenv("HOME");
+  if (home == NULL) return std::string();
+  return std::string(home) + "/" + kLocalDir;
+#endif
+}
+
+}  // namespace lczero