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directory_iterator.cpp (10690B)

      1 //===------------------ directory_iterator.cpp ----------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is dual licensed under the MIT and the University of Illinois Open
      6 // Source Licenses. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "filesystem"
     11 #include "__config"
     12 #if defined(_LIBCPP_WIN32API)
     13 #define WIN32_LEAN_AND_MEAN
     14 #include <Windows.h>
     15 #else
     16 #include <dirent.h>
     17 #endif
     18 #include <errno.h>
     19 
     20 #include "filesystem_common.h"
     21 
     22 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
     23 
     24 namespace detail {
     25 namespace {
     26 
     27 #if !defined(_LIBCPP_WIN32API)
     28 template <class DirEntT, class = decltype(DirEntT::d_type)>
     29 static file_type get_file_type(DirEntT* ent, int) {
     30   switch (ent->d_type) {
     31   case DT_BLK:
     32     return file_type::block;
     33   case DT_CHR:
     34     return file_type::character;
     35   case DT_DIR:
     36     return file_type::directory;
     37   case DT_FIFO:
     38     return file_type::fifo;
     39   case DT_LNK:
     40     return file_type::symlink;
     41   case DT_REG:
     42     return file_type::regular;
     43   case DT_SOCK:
     44     return file_type::socket;
     45   // Unlike in lstat, hitting "unknown" here simply means that the underlying
     46   // filesystem doesn't support d_type. Report is as 'none' so we correctly
     47   // set the cache to empty.
     48   case DT_UNKNOWN:
     49     break;
     50   }
     51   return file_type::none;
     52 }
     53 
     54 template <class DirEntT>
     55 static file_type get_file_type(DirEntT* ent, long) {
     56   return file_type::none;
     57 }
     58 
     59 static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
     60                                                   error_code& ec) {
     61   struct dirent* dir_entry_ptr = nullptr;
     62   errno = 0; // zero errno in order to detect errors
     63   ec.clear();
     64   if ((dir_entry_ptr = ::readdir(dir_stream)) == nullptr) {
     65     if (errno)
     66       ec = capture_errno();
     67     return {};
     68   } else {
     69     return {dir_entry_ptr->d_name, get_file_type(dir_entry_ptr, 0)};
     70   }
     71 }
     72 #else
     73 
     74 static file_type get_file_type(const WIN32_FIND_DATA& data) {
     75   //auto attrs = data.dwFileAttributes;
     76   // FIXME(EricWF)
     77   return file_type::unknown;
     78 }
     79 static uintmax_t get_file_size(const WIN32_FIND_DATA& data) {
     80   return (data.nFileSizeHight * (MAXDWORD + 1)) + data.nFileSizeLow;
     81 }
     82 static file_time_type get_write_time(const WIN32_FIND_DATA& data) {
     83   ULARGE_INTEGER tmp;
     84   FILETIME& time = data.ftLastWriteTime;
     85   tmp.u.LowPart = time.dwLowDateTime;
     86   tmp.u.HighPart = time.dwHighDateTime;
     87   return file_time_type(file_time_type::duration(time.QuadPart));
     88 }
     89 
     90 #endif
     91 
     92 } // namespace
     93 } // namespace detail
     94 
     95 using detail::ErrorHandler;
     96 
     97 #if defined(_LIBCPP_WIN32API)
     98 class __dir_stream {
     99 public:
    100   __dir_stream() = delete;
    101   __dir_stream& operator=(const __dir_stream&) = delete;
    102 
    103   __dir_stream(__dir_stream&& __ds) noexcept : __stream_(__ds.__stream_),
    104                                                __root_(move(__ds.__root_)),
    105                                                __entry_(move(__ds.__entry_)) {
    106     __ds.__stream_ = INVALID_HANDLE_VALUE;
    107   }
    108 
    109   __dir_stream(const path& root, directory_options opts, error_code& ec)
    110       : __stream_(INVALID_HANDLE_VALUE), __root_(root) {
    111     __stream_ = ::FindFirstFileEx(root.c_str(), &__data_);
    112     if (__stream_ == INVALID_HANDLE_VALUE) {
    113       ec = error_code(::GetLastError(), generic_category());
    114       const bool ignore_permission_denied =
    115           bool(opts & directory_options::skip_permission_denied);
    116       if (ignore_permission_denied && ec.value() == ERROR_ACCESS_DENIED)
    117         ec.clear();
    118       return;
    119     }
    120   }
    121 
    122   ~__dir_stream() noexcept {
    123     if (__stream_ == INVALID_HANDLE_VALUE)
    124       return;
    125     close();
    126   }
    127 
    128   bool good() const noexcept { return __stream_ != INVALID_HANDLE_VALUE; }
    129 
    130   bool advance(error_code& ec) {
    131     while (::FindNextFile(__stream_, &__data_)) {
    132       if (!strcmp(__data_.cFileName, ".") || strcmp(__data_.cFileName, ".."))
    133         continue;
    134       // FIXME: Cache more of this
    135       //directory_entry::__cached_data cdata;
    136       //cdata.__type_ = get_file_type(__data_);
    137       //cdata.__size_ = get_file_size(__data_);
    138       //cdata.__write_time_ = get_write_time(__data_);
    139       __entry_.__assign_iter_entry(
    140           __root_ / __data_.cFileName,
    141           directory_entry::__create_iter_result(get_file_type(__data)));
    142       return true;
    143     }
    144     ec = error_code(::GetLastError(), generic_category());
    145     close();
    146     return false;
    147   }
    148 
    149 private:
    150   error_code close() noexcept {
    151     error_code ec;
    152     if (!::FindClose(__stream_))
    153       ec = error_code(::GetLastError(), generic_category());
    154     __stream_ = INVALID_HANDLE_VALUE;
    155     return ec;
    156   }
    157 
    158   HANDLE __stream_{INVALID_HANDLE_VALUE};
    159   WIN32_FIND_DATA __data_;
    160 
    161 public:
    162   path __root_;
    163   directory_entry __entry_;
    164 };
    165 #else
    166 class __dir_stream {
    167 public:
    168   __dir_stream() = delete;
    169   __dir_stream& operator=(const __dir_stream&) = delete;
    170 
    171   __dir_stream(__dir_stream&& other) noexcept : __stream_(other.__stream_),
    172                                                 __root_(move(other.__root_)),
    173                                                 __entry_(move(other.__entry_)) {
    174     other.__stream_ = nullptr;
    175   }
    176 
    177   __dir_stream(const path& root, directory_options opts, error_code& ec)
    178       : __stream_(nullptr), __root_(root) {
    179     if ((__stream_ = ::opendir(root.c_str())) == nullptr) {
    180       ec = detail::capture_errno();
    181       const bool allow_eacess =
    182           bool(opts & directory_options::skip_permission_denied);
    183       if (allow_eacess && ec.value() == EACCES)
    184         ec.clear();
    185       return;
    186     }
    187     advance(ec);
    188   }
    189 
    190   ~__dir_stream() noexcept {
    191     if (__stream_)
    192       close();
    193   }
    194 
    195   bool good() const noexcept { return __stream_ != nullptr; }
    196 
    197   bool advance(error_code& ec) {
    198     while (true) {
    199       auto str_type_pair = detail::posix_readdir(__stream_, ec);
    200       auto& str = str_type_pair.first;
    201       if (str == "." || str == "..") {
    202         continue;
    203       } else if (ec || str.empty()) {
    204         close();
    205         return false;
    206       } else {
    207         __entry_.__assign_iter_entry(
    208             __root_ / str,
    209             directory_entry::__create_iter_result(str_type_pair.second));
    210         return true;
    211       }
    212     }
    213   }
    214 
    215 private:
    216   error_code close() noexcept {
    217     error_code m_ec;
    218     if (::closedir(__stream_) == -1)
    219       m_ec = detail::capture_errno();
    220     __stream_ = nullptr;
    221     return m_ec;
    222   }
    223 
    224   DIR* __stream_{nullptr};
    225 
    226 public:
    227   path __root_;
    228   directory_entry __entry_;
    229 };
    230 #endif
    231 
    232 // directory_iterator
    233 
    234 directory_iterator::directory_iterator(const path& p, error_code* ec,
    235                                        directory_options opts) {
    236   ErrorHandler<void> err("directory_iterator::directory_iterator(...)", ec, &p);
    237 
    238   error_code m_ec;
    239   __imp_ = make_shared<__dir_stream>(p, opts, m_ec);
    240   if (ec)
    241     *ec = m_ec;
    242   if (!__imp_->good()) {
    243     __imp_.reset();
    244     if (m_ec)
    245       err.report(m_ec);
    246   }
    247 }
    248 
    249 directory_iterator& directory_iterator::__increment(error_code* ec) {
    250   _LIBCPP_ASSERT(__imp_, "Attempting to increment an invalid iterator");
    251   ErrorHandler<void> err("directory_iterator::operator++()", ec);
    252 
    253   error_code m_ec;
    254   if (!__imp_->advance(m_ec)) {
    255     path root = move(__imp_->__root_);
    256     __imp_.reset();
    257     if (m_ec)
    258       err.report(m_ec, "at root \"%s\"", root);
    259   }
    260   return *this;
    261 }
    262 
    263 directory_entry const& directory_iterator::__dereference() const {
    264   _LIBCPP_ASSERT(__imp_, "Attempting to dereference an invalid iterator");
    265   return __imp_->__entry_;
    266 }
    267 
    268 // recursive_directory_iterator
    269 
    270 struct recursive_directory_iterator::__shared_imp {
    271   stack<__dir_stream> __stack_;
    272   directory_options __options_;
    273 };
    274 
    275 recursive_directory_iterator::recursive_directory_iterator(
    276     const path& p, directory_options opt, error_code* ec)
    277     : __imp_(nullptr), __rec_(true) {
    278   ErrorHandler<void> err("recursive_directory_iterator", ec, &p);
    279 
    280   error_code m_ec;
    281   __dir_stream new_s(p, opt, m_ec);
    282   if (m_ec)
    283     err.report(m_ec);
    284   if (m_ec || !new_s.good())
    285     return;
    286 
    287   __imp_ = make_shared<__shared_imp>();
    288   __imp_->__options_ = opt;
    289   __imp_->__stack_.push(move(new_s));
    290 }
    291 
    292 void recursive_directory_iterator::__pop(error_code* ec) {
    293   _LIBCPP_ASSERT(__imp_, "Popping the end iterator");
    294   if (ec)
    295     ec->clear();
    296   __imp_->__stack_.pop();
    297   if (__imp_->__stack_.size() == 0)
    298     __imp_.reset();
    299   else
    300     __advance(ec);
    301 }
    302 
    303 directory_options recursive_directory_iterator::options() const {
    304   return __imp_->__options_;
    305 }
    306 
    307 int recursive_directory_iterator::depth() const {
    308   return __imp_->__stack_.size() - 1;
    309 }
    310 
    311 const directory_entry& recursive_directory_iterator::__dereference() const {
    312   return __imp_->__stack_.top().__entry_;
    313 }
    314 
    315 recursive_directory_iterator&
    316 recursive_directory_iterator::__increment(error_code* ec) {
    317   if (ec)
    318     ec->clear();
    319   if (recursion_pending()) {
    320     if (__try_recursion(ec) || (ec && *ec))
    321       return *this;
    322   }
    323   __rec_ = true;
    324   __advance(ec);
    325   return *this;
    326 }
    327 
    328 void recursive_directory_iterator::__advance(error_code* ec) {
    329   ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
    330 
    331   const directory_iterator end_it;
    332   auto& stack = __imp_->__stack_;
    333   error_code m_ec;
    334   while (stack.size() > 0) {
    335     if (stack.top().advance(m_ec))
    336       return;
    337     if (m_ec)
    338       break;
    339     stack.pop();
    340   }
    341 
    342   if (m_ec) {
    343     path root = move(stack.top().__root_);
    344     __imp_.reset();
    345     err.report(m_ec, "at root \"%s\"", root);
    346   } else {
    347     __imp_.reset();
    348   }
    349 }
    350 
    351 bool recursive_directory_iterator::__try_recursion(error_code* ec) {
    352   ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
    353 
    354   bool rec_sym = bool(options() & directory_options::follow_directory_symlink);
    355 
    356   auto& curr_it = __imp_->__stack_.top();
    357 
    358   bool skip_rec = false;
    359   error_code m_ec;
    360   if (!rec_sym) {
    361     file_status st(curr_it.__entry_.__get_sym_ft(&m_ec));
    362     if (m_ec && status_known(st))
    363       m_ec.clear();
    364     if (m_ec || is_symlink(st) || !is_directory(st))
    365       skip_rec = true;
    366   } else {
    367     file_status st(curr_it.__entry_.__get_ft(&m_ec));
    368     if (m_ec && status_known(st))
    369       m_ec.clear();
    370     if (m_ec || !is_directory(st))
    371       skip_rec = true;
    372   }
    373 
    374   if (!skip_rec) {
    375     __dir_stream new_it(curr_it.__entry_.path(), __imp_->__options_, m_ec);
    376     if (new_it.good()) {
    377       __imp_->__stack_.push(move(new_it));
    378       return true;
    379     }
    380   }
    381   if (m_ec) {
    382     const bool allow_eacess =
    383         bool(__imp_->__options_ & directory_options::skip_permission_denied);
    384     if (m_ec.value() == EACCES && allow_eacess) {
    385       if (ec)
    386         ec->clear();
    387     } else {
    388       path at_ent = move(curr_it.__entry_.__p_);
    389       __imp_.reset();
    390       err.report(m_ec, "attempting recursion into \"%s\"", at_ent);
    391     }
    392   }
    393   return false;
    394 }
    395 
    396 _LIBCPP_END_NAMESPACE_FILESYSTEM