zstd/contrib/pzstd/utils/FileSystem.h
2016-09-06 14:00:20 -07:00

78 lines
2.0 KiB
C++

/**
* Copyright (c) 2016-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#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 {
#if defined(_MSC_VER)
using file_status = struct ::_stat64;
#else
using file_status = struct ::stat;
#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/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;
}
}