1 files changed, 94 insertions, 0 deletions
diff --git a/src/zstd/contrib/pzstd/utils/FileSystem.h b/src/zstd/contrib/pzstd/utils/FileSystem.h
new file mode 100644
index 000000000..3cfbe86e5
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/FileSystem.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "utils/Range.h"
+
+#include <sys/stat.h>
+#include <cerrno>
+#include <cstdint>
+#include <system_error>
+
+// A small subset of `std::filesystem`.
+// `std::filesystem` should be a drop in replacement.
+// See http://en.cppreference.com/w/cpp/filesystem for documentation.
+
+namespace pzstd {
+
+// using file_status = ... causes gcc to emit a false positive warning
+#if defined(_MSC_VER)
+typedef struct ::_stat64 file_status;
+#else
+typedef struct ::stat file_status;
+#endif
+
+/// http://en.cppreference.com/w/cpp/filesystem/status
+inline file_status status(StringPiece path, std::error_code& ec) noexcept {
+  file_status status;
+#if defined(_MSC_VER)
+  const auto error = ::_stat64(path.data(), &status);
+#else
+  const auto error = ::stat(path.data(), &status);
+#endif
+  if (error) {
+    ec.assign(errno, std::generic_category());
+  } else {
+    ec.clear();
+  }
+  return status;
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_regular_file
+inline bool is_regular_file(file_status status) noexcept {
+#if defined(S_ISREG)
+  return S_ISREG(status.st_mode);
+#elif !defined(S_ISREG) && defined(S_IFMT) && defined(S_IFREG)
+  return (status.st_mode & S_IFMT) == S_IFREG;
+#else
+  static_assert(false, "No POSIX stat() support.");
+#endif
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_regular_file
+inline bool is_regular_file(StringPiece path, std::error_code& ec) noexcept {
+  return is_regular_file(status(path, ec));
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_directory
+inline bool is_directory(file_status status) noexcept {
+#if defined(S_ISDIR)
+  return S_ISDIR(status.st_mode);
+#elif !defined(S_ISDIR) && defined(S_IFMT) && defined(S_IFDIR)
+  return (status.st_mode & S_IFMT) == S_IFDIR;
+#else
+  static_assert(false, "NO POSIX stat() support.");
+#endif
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_directory
+inline bool is_directory(StringPiece path, std::error_code& ec) noexcept {
+  return is_directory(status(path, ec));
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/file_size
+inline std::uintmax_t file_size(
+    StringPiece path,
+    std::error_code& ec) noexcept {
+  auto stat = status(path, ec);
+  if (ec) {
+    return -1;
+  }
+  if (!is_regular_file(stat)) {
+    ec.assign(ENOTSUP, std::generic_category());
+    return -1;
+  }
+  ec.clear();
+  return stat.st_size;
+}
+}