| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This source code is licensed under both the BSD-style license (found in the |
| 6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| 7 | * in the COPYING file in the root directory of this source tree). |
| 8 | */ |
| 9 | #pragma once |
| 10 | |
| 11 | #include "utils/Portability.h" |
| 12 | #include "utils/Range.h" |
| 13 | |
| 14 | #include <sys/stat.h> |
| 15 | #include <cerrno> |
| 16 | #include <cstdint> |
| 17 | #include <limits> |
| 18 | #include <system_error> |
| 19 | |
| 20 | // A small subset of `std::filesystem`. |
| 21 | // `std::filesystem` should be a drop in replacement. |
| 22 | // See https://en.cppreference.com/w/cpp/filesystem for documentation. |
| 23 | |
| 24 | namespace pzstd { |
| 25 | |
| 26 | // using file_status = ... causes gcc to emit a false positive warning |
| 27 | #if defined(_MSC_VER) |
| 28 | typedef struct ::_stat64 file_status; |
| 29 | #else |
| 30 | typedef struct ::stat file_status; |
| 31 | #endif |
| 32 | |
| 33 | /// https://en.cppreference.com/w/cpp/filesystem/status |
| 34 | inline file_status status(StringPiece path, std::error_code& ec) noexcept { |
| 35 | file_status status; |
| 36 | #if defined(_MSC_VER) |
| 37 | const auto error = ::_stat64(path.data(), &status); |
| 38 | #else |
| 39 | const auto error = ::stat(path.data(), &status); |
| 40 | #endif |
| 41 | if (error) { |
| 42 | ec.assign(errno, std::generic_category()); |
| 43 | } else { |
| 44 | ec.clear(); |
| 45 | } |
| 46 | return status; |
| 47 | } |
| 48 | |
| 49 | /// https://en.cppreference.com/w/cpp/filesystem/is_regular_file |
| 50 | inline bool is_regular_file(file_status status) noexcept { |
| 51 | #if defined(S_ISREG) |
| 52 | return S_ISREG(status.st_mode); |
| 53 | #elif !defined(S_ISREG) && defined(S_IFMT) && defined(S_IFREG) |
| 54 | return (status.st_mode & S_IFMT) == S_IFREG; |
| 55 | #else |
| 56 | static_assert(false, "No POSIX stat() support."); |
| 57 | #endif |
| 58 | } |
| 59 | |
| 60 | /// https://en.cppreference.com/w/cpp/filesystem/is_regular_file |
| 61 | inline bool is_regular_file(StringPiece path, std::error_code& ec) noexcept { |
| 62 | return is_regular_file(status(path, ec)); |
| 63 | } |
| 64 | |
| 65 | /// https://en.cppreference.com/w/cpp/filesystem/is_directory |
| 66 | inline bool is_directory(file_status status) noexcept { |
| 67 | #if defined(S_ISDIR) |
| 68 | return S_ISDIR(status.st_mode); |
| 69 | #elif !defined(S_ISDIR) && defined(S_IFMT) && defined(S_IFDIR) |
| 70 | return (status.st_mode & S_IFMT) == S_IFDIR; |
| 71 | #else |
| 72 | static_assert(false, "NO POSIX stat() support."); |
| 73 | #endif |
| 74 | } |
| 75 | |
| 76 | /// https://en.cppreference.com/w/cpp/filesystem/is_directory |
| 77 | inline bool is_directory(StringPiece path, std::error_code& ec) noexcept { |
| 78 | return is_directory(status(path, ec)); |
| 79 | } |
| 80 | |
| 81 | /// https://en.cppreference.com/w/cpp/filesystem/file_size |
| 82 | inline std::uintmax_t file_size( |
| 83 | StringPiece path, |
| 84 | std::error_code& ec) noexcept { |
| 85 | auto stat = status(path, ec); |
| 86 | if (ec) { |
| 87 | return std::numeric_limits<uintmax_t>::max(); |
| 88 | } |
| 89 | if (!is_regular_file(stat)) { |
| 90 | ec.assign(ENOTSUP, std::generic_category()); |
| 91 | return std::numeric_limits<uintmax_t>::max(); |
| 92 | } |
| 93 | ec.clear(); |
| 94 | return stat.st_size; |
| 95 | } |
| 96 | } |