Issue #11016: Add C implementation of the stat module as _stat

Doc/library/stat.rst

@@ -6,7 +6,8 @@
               os.lstat() and os.fstat().
 .. sectionauthor:: Skip Montanaro <skip@automatrix.com>
 
-**Source code:** :source:`Lib/stat.py`
+**Source code:** :source:`Modules/_stat.c`
+                 :source:`Lib/stat.py`
 
 --------------
 
@@ -15,6 +16,9 @@ results of :func:`os.stat`, :func:`os.fstat` and :func:`os.lstat` (if they
 exist).  For complete details about the :c:func:`stat`, :c:func:`fstat` and
 :c:func:`lstat` calls, consult the documentation for your system.
 
+.. versionchanged:: 3.4
+   The stat module is backed by a C implementation.
+
 The :mod:`stat` module defines the following functions to test for specific file
 types:
 
@@ -53,6 +57,24 @@ types:
 
    Return non-zero if the mode is from a socket.
 
+.. function:: S_ISDOOR(mode)
+
+   Return non-zero if the mode is from a door.
+
+   .. versionadded:: 3.4
+
+.. function:: S_ISPORT(mode)
+
+   Return non-zero if the mode is from an event port.
+
+   .. versionadded:: 3.4
+
+.. function:: S_ISWHT(mode)
+
+   Return non-zero if the mode is from a whiteout.
+
+   .. versionadded:: 3.4
+
 Two additional functions are defined for more general manipulation of the file's
 mode:
 
@@ -113,6 +135,10 @@ readable string:
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.4
+      The function supports :data:`S_IFDOOR`, :data:`S_IFPORT` and
+      :data:`S_IFWHT`.
+
 
 All the variables below are simply symbolic indexes into the 10-tuple returned
 by :func:`os.stat`, :func:`os.fstat` or :func:`os.lstat`.
@@ -210,6 +236,29 @@ Use of the functions above is more portable than use of the first set of flags:
 
    FIFO.
 
+.. data:: S_IFDOOR
+
+   Door.
+
+   .. versionadded:: 3.4
+
+.. data:: S_IFPORT
+
+   Event port.
+
+   .. versionadded:: 3.4
+
+.. data:: S_IFWHT
+
+   Whiteout.
+
+   .. versionadded:: 3.4
+
+.. note::
+
+   :data:`S_IFDOOR`, :data:`S_IFPORT` or :data:`S_IFWHT` are defined as
+   0 when the platform does not have support for the file types.
+
 The following flags can also be used in the *mode* argument of :func:`os.chmod`:
 
 .. data:: S_ISUID

Doc/whatsnew/3.4.rst

@@ -182,7 +182,6 @@ functools
 
 New :func:`functools.singledispatch` decorator: see the :pep:`443`.
 
-
 smtplib
 -------
 
@@ -213,6 +212,12 @@ wave
 The :meth:`~wave.getparams` method now returns a namedtuple rather than a
 plain tuple.  (Contributed by Claudiu Popa in :issue:`17487`.)
 
+stat
+---
+
+The stat module is now backed by a C implementation in :mod:`_stat`. A C
+implementation is required as most of the values aren't standardized and
+platform-dependent.  (Contributed by Christian Heimes in :issue:`11016`.)
 
 Optimizations
 =============

Lib/stat.py

@@ -147,3 +147,9 @@ def filemode(mode):
         else:
             perm.append("-")
     return "".join(perm)
+
+# If available, use C implementation
+try:
+    from _stat import *
+except ModuleNotFoundError:
+    pass

Lib/test/test_stat.py

 import unittest
 import os
 from test.support import TESTFN, run_unittest, import_fresh_module
-import stat
+
+c_stat = import_fresh_module('stat', fresh=['_stat'])
+py_stat = import_fresh_module('stat', blocked=['_stat'])
 
 class TestFilemode(unittest.TestCase):
+    statmod = None
+
     file_flags = {'SF_APPEND', 'SF_ARCHIVED', 'SF_IMMUTABLE', 'SF_NOUNLINK',
                   'SF_SNAPSHOT', 'UF_APPEND', 'UF_COMPRESSED', 'UF_HIDDEN',
                   'UF_IMMUTABLE', 'UF_NODUMP', 'UF_NOUNLINK', 'UF_OPAQUE'}
@@ -60,17 +64,17 @@ class TestFilemode(unittest.TestCase):
 
     def get_mode(self, fname=TESTFN):
         st_mode = os.lstat(fname).st_mode
-        modestr = stat.filemode(st_mode)
+        modestr = self.statmod.filemode(st_mode)
         return st_mode, modestr
 
     def assertS_IS(self, name, mode):
         # test format, lstrip is for S_IFIFO
-        fmt = getattr(stat, "S_IF" + name.lstrip("F"))
-        self.assertEqual(stat.S_IFMT(mode), fmt)
+        fmt = getattr(self.statmod, "S_IF" + name.lstrip("F"))
+        self.assertEqual(self.statmod.S_IFMT(mode), fmt)
         # test that just one function returns true
         testname = "S_IS" + name
         for funcname in self.format_funcs:
-            func = getattr(stat, funcname, None)
+            func = getattr(self.statmod, funcname, None)
             if func is None:
                 if funcname == testname:
                     raise ValueError(funcname)
@@ -88,35 +92,35 @@ class TestFilemode(unittest.TestCase):
             st_mode, modestr = self.get_mode()
             self.assertEqual(modestr, '-rwx------')
             self.assertS_IS("REG", st_mode)
-            self.assertEqual(stat.S_IMODE(st_mode),
-                             stat.S_IRWXU)
+            self.assertEqual(self.statmod.S_IMODE(st_mode),
+                             self.statmod.S_IRWXU)
 
             os.chmod(TESTFN, 0o070)
             st_mode, modestr = self.get_mode()
             self.assertEqual(modestr, '----rwx---')
             self.assertS_IS("REG", st_mode)
-            self.assertEqual(stat.S_IMODE(st_mode),
-                             stat.S_IRWXG)
+            self.assertEqual(self.statmod.S_IMODE(st_mode),
+                             self.statmod.S_IRWXG)
 
             os.chmod(TESTFN, 0o007)
             st_mode, modestr = self.get_mode()
             self.assertEqual(modestr, '-------rwx')
             self.assertS_IS("REG", st_mode)
-            self.assertEqual(stat.S_IMODE(st_mode),
-                             stat.S_IRWXO)
+            self.assertEqual(self.statmod.S_IMODE(st_mode),
+                             self.statmod.S_IRWXO)
 
             os.chmod(TESTFN, 0o444)
             st_mode, modestr = self.get_mode()
             self.assertS_IS("REG", st_mode)
             self.assertEqual(modestr, '-r--r--r--')
-            self.assertEqual(stat.S_IMODE(st_mode), 0o444)
+            self.assertEqual(self.statmod.S_IMODE(st_mode), 0o444)
         else:
             os.chmod(TESTFN, 0o700)
             st_mode, modestr = self.get_mode()
             self.assertEqual(modestr[:3], '-rw')
             self.assertS_IS("REG", st_mode)
-            self.assertEqual(stat.S_IFMT(st_mode),
-                             stat.S_IFREG)
+            self.assertEqual(self.statmod.S_IFMT(st_mode),
+                             self.statmod.S_IFREG)
 
     def test_directory(self):
         os.mkdir(TESTFN)
@@ -162,25 +166,38 @@ class TestFilemode(unittest.TestCase):
 
     def test_module_attributes(self):
         for key, value in self.stat_struct.items():
-            modvalue = getattr(stat, key)
+            modvalue = getattr(self.statmod, key)
             self.assertEqual(value, modvalue, key)
         for key, value in self.permission_bits.items():
-            modvalue = getattr(stat, key)
+            modvalue = getattr(self.statmod, key)
             self.assertEqual(value, modvalue, key)
         for key in self.file_flags:
-            modvalue = getattr(stat, key)
+            modvalue = getattr(self.statmod, key)
             self.assertIsInstance(modvalue, int)
         for key in self.formats:
-            modvalue = getattr(stat, key)
+            modvalue = getattr(self.statmod, key)
             self.assertIsInstance(modvalue, int)
         for key in self.format_funcs:
-            func = getattr(stat, key)
+            func = getattr(self.statmod, key)
             self.assertTrue(callable(func))
             self.assertEqual(func(0), 0)
 
 
+class TestFilemodeCStat(TestFilemode):
+    statmod = c_stat
+
+    formats = TestFilemode.formats | {'S_IFDOOR', 'S_IFPORT', 'S_IFWHT'}
+    format_funcss = TestFilemode.format_funcs | {'S_ISDOOR', 'S_ISPORT',
+                                                 'S_ISWHT'}
+
+
+class TestFilemodePyStat(TestFilemode):
+    statmod = py_stat
+
+
 def test_main():
-    run_unittest(TestFilemode)
+    run_unittest(TestFilemodeCStat)
+    run_unittest(TestFilemodePyStat)
 
 if __name__ == '__main__':
     test_main()

Misc/NEWS

@@ -123,6 +123,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #11016: Add C implementation of the stat module as _stat.
+
 - Issue #18248: Fix libffi build on AIX.
 
 - Issue #18259: Declare sethostname in socketmodule.c for AIX

Modules/Setup.dist

@@ -117,6 +117,7 @@ _operator _operator.c	        # operator.add() and similar goodies
 _collections _collectionsmodule.c # Container types
 itertools itertoolsmodule.c    # Functions creating iterators for efficient looping 
 atexit atexitmodule.c      # Register functions to be run at interpreter-shutdown
+_stat _stat.c			# stat.h interface
 
 # access to ISO C locale support
 _locale _localemodule.c  # -lintl

PC/VS9.0/pythoncore.vcproj

@@ -1154,6 +1154,10 @@
 				RelativePath="..\..\Modules\signalmodule.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\Modules\_stat.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\Modules\symtablemodule.c"
 				>

PCbuild/pythoncore.vcxproj

@@ -525,6 +525,7 @@
     <ClCompile Include="..\Modules\sha256module.c" />
     <ClCompile Include="..\Modules\sha512module.c" />
     <ClCompile Include="..\Modules\signalmodule.c" />
+    <ClCompile Include="..\Modules\_stat.c" />
     <ClCompile Include="..\Modules\symtablemodule.c" />
     <ClCompile Include="..\Modules\_threadmodule.c" />
     <ClCompile Include="..\Modules\timemodule.c" />