C++ detail::set_or_throw方法代码示例

bool __fs_is_empty(const path& p, std::error_code *ec)
{
    if (ec) ec->clear();
    std::error_code m_ec;
    struct ::stat pst;
    auto st = detail::posix_stat(p, pst, &m_ec);
    if (m_ec) {
        set_or_throw(m_ec, ec, "is_empty", p);
        return false;
    }
    else if (!is_directory(st) && !is_regular_file(st)) {
        m_ec = make_error_code(errc::not_supported);
        set_or_throw(m_ec, ec, "is_empty");
        return false;
    }
    else if (is_directory(st)) {
        auto it = ec ? directory_iterator(p, *ec) : directory_iterator(p);
        if (ec && *ec)
            return false;
        return it == directory_iterator{};
    }
    else if (is_regular_file(st))
        return static_cast<std::uintmax_t>(pst.st_size) == 0;

    _LIBCPP_UNREACHABLE();
}

bool __create_directories(const path& p, std::error_code *ec)
{
    std::error_code m_ec;
    auto const st = detail::posix_stat(p, &m_ec);
    if (!status_known(st)) {
        set_or_throw(m_ec, ec, "create_directories", p);
        return false;
    }
    else if (is_directory(st)) {
        if (ec) ec->clear();
        return false;
    }
    else if (exists(st)) {
        set_or_throw(make_error_code(errc::file_exists),
                     ec, "create_directories", p);
        return false;
    }

    const path parent = p.parent_path();
    if (!parent.empty()) {
        const file_status parent_st = status(parent, m_ec);
        if (not status_known(parent_st)) {
            set_or_throw(m_ec, ec, "create_directories", p);
            return false;
        }
        if (not exists(parent_st)) {
            __create_directories(parent, ec);
            if (ec && *ec) { return false; }
        }
    }
    return __create_directory(p, ec);
}

bool __copy_file(const path& from, const path& to, copy_options options,
                 std::error_code *ec)
{
    using StatT = struct ::stat;
    if (ec)
      ec->clear();

    std::error_code m_ec;
    StatT from_stat;
    auto from_st = detail::posix_stat(from, from_stat, &m_ec);
    if (not is_regular_file(from_st)) {
        if (not m_ec)
            m_ec = make_error_code(errc::not_supported);
        set_or_throw(m_ec, ec, "copy_file", from, to);
        return false;
    }

    StatT to_stat;
    auto to_st = detail::posix_stat(to, to_stat, &m_ec);
    if (!status_known(to_st)) {
        set_or_throw(m_ec, ec, "copy_file", from, to);
        return false;
    }

    const bool to_exists = exists(to_st);
    if (to_exists && !is_regular_file(to_st)) {
        set_or_throw(make_error_code(errc::not_supported), ec, "copy_file", from, to);
        return false;
    }
    if (to_exists && detail::stat_equivalent(from_stat, to_stat)) {
      set_or_throw(make_error_code(errc::file_exists), ec, "copy_file", from,
                   to);
      return false;
    }
    if (to_exists && bool(copy_options::skip_existing & options)) {
        return false;
    }
    else if (to_exists && bool(copy_options::update_existing & options)) {
        auto from_time = __last_write_time(from, ec);
        if (ec && *ec) { return false; }
        auto to_time = __last_write_time(to, ec);
        if (ec && *ec) { return false; }
        if (from_time <= to_time) {
            return false;
        }
        return detail::copy_file_impl(from, to, from_st.permissions(), ec);
    }
    else if (!to_exists || bool(copy_options::overwrite_existing & options)) {
        return detail::copy_file_impl(from, to, from_st.permissions(), ec);
    }
    else {
      set_or_throw(make_error_code(errc::file_exists), ec, "copy_file", from,
                   to);
        return false;
    }

    _LIBCPP_UNREACHABLE();
}

void __last_write_time(const path& p, file_time_type new_time,
                       std::error_code *ec)
{
    using namespace std::chrono;
    std::error_code m_ec;

    // We can use the presence of UTIME_OMIT to detect platforms that do not
    // provide utimensat.
#if !defined(UTIME_OMIT)
    // This implementation has a race condition between determining the
    // last access time and attempting to set it to the same value using
    // ::utimes
    struct ::stat st;
    file_status fst = detail::posix_stat(p, st, &m_ec);
    if (m_ec && !status_known(fst)) {
        set_or_throw(m_ec, ec, "last_write_time", p);
        return;
    }
    struct ::timeval tbuf[2];
    tbuf[0].tv_sec = st.st_atime;
    tbuf[0].tv_usec = 0;
    const bool overflowed = !detail::set_times_checked<microseconds>(
        &tbuf[1].tv_sec, &tbuf[1].tv_usec, new_time);

    if (overflowed) {
        set_or_throw(make_error_code(errc::invalid_argument), ec,
                     "last_write_time", p);
        return;
    }
    if (::utimes(p.c_str(), tbuf) == -1) {
        m_ec = detail::capture_errno();
    }
#else
    struct ::timespec tbuf[2];
    tbuf[0].tv_sec = 0;
    tbuf[0].tv_nsec = UTIME_OMIT;

    const bool overflowed = !detail::set_times_checked<nanoseconds>(
        &tbuf[1].tv_sec, &tbuf[1].tv_nsec, new_time);
    if (overflowed) {
        set_or_throw(make_error_code(errc::invalid_argument),
            ec, "last_write_time", p);
        return;
    }
    if (::utimensat(AT_FDCWD, p.c_str(), tbuf, 0) == -1) {
        m_ec = detail::capture_errno();
    }
#endif
    if (m_ec)
        set_or_throw(m_ec, ec, "last_write_time", p);
    else if (ec)
        ec->clear();
}

void __last_write_time(const path& p, file_time_type new_time,
                       std::error_code *ec)
{
    using namespace std::chrono;
    std::error_code m_ec;

#if !defined(_LIBCXX_USE_UTIMENSAT)
    // This implementation has a race condition between determining the
    // last access time and attempting to set it to the same value using
    // ::utimes
    struct ::stat st;
    file_status fst = detail::posix_stat(p, st, &m_ec);
    if (m_ec && !status_known(fst)) {
        set_or_throw(m_ec, ec, "last_write_time", p);
        return;
    }
    auto atime = detail::extract_atime(st);
    struct ::timeval tbuf[2];
    tbuf[0].tv_sec = atime.tv_sec;
    tbuf[0].tv_usec = duration_cast<microseconds>(nanoseconds(atime.tv_nsec)).count();
    const bool overflowed = !FSTime::set_times_checked<microseconds>(
        &tbuf[1].tv_sec, &tbuf[1].tv_usec, new_time);

    if (overflowed) {
        set_or_throw(make_error_code(errc::invalid_argument), ec,
                     "last_write_time", p);
        return;
    }
    if (::utimes(p.c_str(), tbuf) == -1) {
        m_ec = detail::capture_errno();
    }
#else
    struct ::timespec tbuf[2];
    tbuf[0].tv_sec = 0;
    tbuf[0].tv_nsec = UTIME_OMIT;

    const bool overflowed = !FSTime::set_times_checked<nanoseconds>(
        &tbuf[1].tv_sec, &tbuf[1].tv_nsec, new_time);
    if (overflowed) {
        set_or_throw(make_error_code(errc::invalid_argument),
            ec, "last_write_time", p);
        return;
    }
    if (::utimensat(AT_FDCWD, p.c_str(), tbuf, 0) == -1) {
        m_ec = detail::capture_errno();
    }
#endif
    if (m_ec)
        set_or_throw(m_ec, ec, "last_write_time", p);
    else if (ec)
        ec->clear();
}

void __create_symlink(path const & from, path const & to, std::error_code *ec) {

    if (::symlink(from.c_str(), to.c_str()) == -1)
        set_or_throw(ec, "create_symlink", from, to);
    else if (ec)
        ec->clear();
}

bool __create_directory(path const & p, path const & attributes,
                        std::error_code *ec)
{
    struct ::stat attr_stat;
    std::error_code mec;
    auto st = detail::posix_stat(attributes, attr_stat, &mec);
    if (!status_known(st)) {
        set_or_throw(mec, ec, "create_directory", p, attributes);
        return false;
    }
    if (ec) ec->clear();
    if (::mkdir(p.c_str(), attr_stat.st_mode) == 0)
        return true;
    if (errno != EEXIST || !is_directory(p))
        set_or_throw(ec, "create_directory", p, attributes);
    return false;
}

bool __remove(const path& p, std::error_code *ec) {
    if (ec) ec->clear();
    if (::remove(p.c_str()) == -1) {
        set_or_throw(ec, "remove", p);
        return false;
    }
    return true;
}

std::uintmax_t __remove_all(const path& p, std::error_code *ec) {
    std::error_code mec;
    auto count = remove_all_impl(p, mec);
    if (mec) {
        set_or_throw(mec, ec, "remove_all", p);
        return static_cast<std::uintmax_t>(-1);
    }
    if (ec) ec->clear();
    return count;
}

void __permissions(const path& p, perms prms, std::error_code *ec)
{

    const bool resolve_symlinks = !bool(perms::symlink_nofollow & prms);
    const bool add_perms = bool(perms::add_perms & prms);
    const bool remove_perms = bool(perms::remove_perms & prms);
    _LIBCPP_ASSERT(!(add_perms && remove_perms),
                   "Both add_perms and remove_perms are set");

    bool set_sym_perms = false;
    prms &= perms::mask;
    if (!resolve_symlinks || (add_perms || remove_perms)) {
        std::error_code m_ec;
        file_status st = resolve_symlinks ? detail::posix_stat(p, &m_ec)
                                          : detail::posix_lstat(p, &m_ec);
        set_sym_perms = is_symlink(st);
        if (m_ec) return set_or_throw(m_ec, ec, "permissions", p);
        _LIBCPP_ASSERT(st.permissions() != perms::unknown,
                       "Permissions unexpectedly unknown");
        if (add_perms)
            prms |= st.permissions();
        else if (remove_perms)
           prms = st.permissions() & ~prms;
    }
    const auto real_perms = detail::posix_convert_perms(prms);

# if defined(AT_SYMLINK_NOFOLLOW) && defined(AT_FDCWD)
    const int flags = set_sym_perms ? AT_SYMLINK_NOFOLLOW : 0;
    if (::fchmodat(AT_FDCWD, p.c_str(), real_perms, flags) == -1) {
        return set_or_throw(ec, "permissions", p);
    }
# else
    if (set_sym_perms)
        return set_or_throw(make_error_code(errc::operation_not_supported),
                            ec, "permissions", p);
    if (::chmod(p.c_str(), real_perms) == -1) {
        return set_or_throw(ec, "permissions", p);
    }
# endif
    if (ec) ec->clear();
}

std::uintmax_t __hard_link_count(const path& p, std::error_code *ec)
{
    std::error_code m_ec;
    struct ::stat st;
    detail::posix_stat(p, st, &m_ec);
    if (m_ec) {
        set_or_throw(m_ec, ec, "hard_link_count", p);
        return static_cast<std::uintmax_t>(-1);
    }
    if (ec) ec->clear();
    return static_cast<std::uintmax_t>(st.st_nlink);
}

path __canonical(path const & orig_p, const path& base, std::error_code *ec)
{
    path p = absolute(orig_p, base);
    char buff[PATH_MAX + 1];
    char *ret;
    if ((ret = ::realpath(p.c_str(), buff)) == nullptr) {
        set_or_throw(ec, "canonical", orig_p, base);
        return {};
    }
    if (ec) ec->clear();
    return {ret};
}

directory_iterator::directory_iterator(const path& p, error_code *ec,
                                       directory_options opts)
{
    std::error_code m_ec;
    __imp_ = make_shared<__dir_stream>(p, opts, m_ec);
    if (ec) *ec = m_ec;
    if (!__imp_->good()) {
        __imp_.reset();
        if (m_ec)
            set_or_throw(m_ec, ec,
                         "directory_iterator::directory_iterator(...)", p);
    }
}

path __current_path(std::error_code *ec) {
    auto size = ::pathconf(".", _PC_PATH_MAX);
    _LIBCPP_ASSERT(size >= 0, "pathconf returned a 0 as max size");

    auto buff = std::unique_ptr<char[]>(new char[size + 1]);
    char* ret;
    if ((ret = ::getcwd(buff.get(), static_cast<size_t>(size))) == nullptr) {
        set_or_throw(ec, "current_path");
        return {};
    }
    if (ec) ec->clear();
    return {buff.get()};
}

bool __fs_is_empty(const path& p, std::error_code *ec)
{
    if (ec) ec->clear();
    std::error_code m_ec;
    struct ::stat pst;
    auto st = detail::posix_stat(p, pst, &m_ec);
    if (is_directory(st))
        return directory_iterator(p) == directory_iterator{};
    else if (is_regular_file(st))
        return static_cast<std::uintmax_t>(pst.st_size) == 0;
    // else
    set_or_throw(m_ec, ec, "is_empty", p);
    return false;
}