Check in Daniel Stutzbach's _fileio.c and test_fileio.py

(see SF#1671314) with small tweaks.
The io module now uses this instead of its own implementation
of the FileIO class, if it can import _fileio.

Lib/io.py

@@ -177,7 +177,7 @@ class RawIOBase:
         raise IOError(".fileno() not supported")
 
 
-class FileIO(RawIOBase):
+class _PyFileIO(RawIOBase):
 
     """Raw I/O implementation for OS files."""
 
@@ -243,6 +243,18 @@ class FileIO(RawIOBase):
         return self._fd
 
 
+try:
+    import _fileio
+except ImportError:
+    # Let's use the Python version
+    FileIO = _PyFileIO
+else:
+    # Create a trivial subclass with the proper inheritance structure
+    class FileIO(_fileio._FileIO, RawIOBase):
+        """Raw I/O implementation for OS files."""
+        # XXX More docs
+
+
 class SocketIO(RawIOBase):
 
     """Raw I/O implementation for stream sockets."""

Lib/test/test_fileio.py

+/* Adapted from test_file.py by Daniel Stutzbach */
+
+import sys
+import os
+import unittest
+from array import array
+from weakref import proxy
+
+from test.test_support import TESTFN, findfile, run_unittest
+from UserList import UserList
+
+import _fileio
+
+class AutoFileTests(unittest.TestCase):
+    # file tests for which a test file is automatically set up
+
+    def setUp(self):
+        self.f = _fileio._FileIO(TESTFN, 'w')
+
+    def tearDown(self):
+        if self.f:
+            self.f.close()
+        os.remove(TESTFN)
+
+    def testWeakRefs(self):
+        # verify weak references
+        p = proxy(self.f)
+        p.write(bytes(range(10)))
+        self.assertEquals(self.f.tell(), p.tell())
+        self.f.close()
+        self.f = None
+        self.assertRaises(ReferenceError, getattr, p, 'tell')
+
+    def testSeekTell(self):
+        self.f.write(bytes(range(20)))
+        self.assertEquals(self.f.tell(), 20)
+        self.f.seek(0)
+        self.assertEquals(self.f.tell(), 0)
+        self.f.seek(10)
+        self.assertEquals(self.f.tell(), 10)
+        self.f.seek(5, 1)
+        self.assertEquals(self.f.tell(), 15)
+        self.f.seek(-5, 1)
+        self.assertEquals(self.f.tell(), 10)
+        self.f.seek(-5, 2)
+        self.assertEquals(self.f.tell(), 15)
+
+    def testAttributes(self):
+        # verify expected attributes exist
+        f = self.f
+        # XXX do we want these?
+        #f.name     # merely shouldn't blow up
+        #f.mode     # ditto
+        #f.closed   # ditto
+
+        # verify the others aren't
+        for attr in 'name', 'mode', 'closed':
+            self.assertRaises((AttributeError, TypeError), setattr, f, attr, 'oops')
+
+    def testReadinto(self):
+        # verify readinto
+        self.f.write(bytes([1, 2]))
+        self.f.close()
+        a = array('b', 'x'*10)
+        self.f = _fileio._FileIO(TESTFN, 'r')
+        n = self.f.readinto(a)
+        self.assertEquals(array('b', [1, 2]), a[:n])
+
+    def testRepr(self):
+        # verify repr works
+        return # XXX doesn't work yet
+        self.assert_(repr(self.f).startswith("<open file '" + TESTFN))
+
+    def testErrors(self):
+        f = self.f
+        self.assert_(not f.isatty())
+        #self.assert_(not f.closed) # XXX Do we want to support these?
+        #self.assertEquals(f.name, TESTFN)
+
+        self.assertRaises(TypeError, f.readinto, "")
+        f.close()
+        #self.assert_(f.closed) # XXX
+
+    def testMethods(self):
+        methods = ['fileno', 'isatty', 'read', 'readinto',
+                   'seek', 'tell', 'truncate', 'write', 'seekable',
+                   'readable', 'writable']
+        if sys.platform.startswith('atheos'):
+            methods.remove('truncate')
+
+        # __exit__ should close the file
+        self.f.__exit__(None, None, None)
+        #self.assert_(self.f.closed) # XXX
+
+        for methodname in methods:
+            method = getattr(self.f, methodname)
+            # should raise on closed file
+            self.assertRaises(ValueError, method)
+
+        # file is closed, __exit__ shouldn't do anything
+        self.assertEquals(self.f.__exit__(None, None, None), None)
+        # it must also return None if an exception was given
+        try:
+            1/0
+        except:
+            self.assertEquals(self.f.__exit__(*sys.exc_info()), None)
+
+
+class OtherFileTests(unittest.TestCase):
+
+    def testAbles(self):
+        try:
+            f = _fileio._FileIO(TESTFN, "w")
+            self.assertEquals(f.readable(), False)
+            self.assertEquals(f.writable(), True)
+            self.assertEquals(f.seekable(), True)
+            f.close()
+            
+            f = _fileio._FileIO(TESTFN, "r")
+            self.assertEquals(f.readable(), True)
+            self.assertEquals(f.writable(), False)
+            self.assertEquals(f.seekable(), True)
+            f.close()
+            
+            f = _fileio._FileIO(TESTFN, "a+")
+            self.assertEquals(f.readable(), True)
+            self.assertEquals(f.writable(), True)
+            self.assertEquals(f.seekable(), True)
+            self.assertEquals(f.isatty(), False)
+            f.close()
+            
+            f = _fileio._FileIO("/dev/tty", "a") # XXX, won't work on e.g., Windows
+            self.assertEquals(f.readable(), False)
+            self.assertEquals(f.writable(), True)
+            ##self.assertEquals(f.seekable(), False) # XXX True on OSX!?
+            self.assertEquals(f.isatty(), True)
+            f.close()
+        finally:
+            os.unlink(TESTFN)
+
+    def testModeStrings(self):
+        # check invalid mode strings
+        for mode in ("", "aU", "wU+", "rb", "rt"):
+            try:
+                f = _fileio._FileIO(TESTFN, mode)
+            except ValueError:
+                pass
+            else:
+                f.close()
+                self.fail('%r is an invalid file mode' % mode)
+
+    def testStdin(self):
+        ## This causes the interpreter to exit on OSF1 v5.1.
+        #if sys.platform != 'osf1V5':
+        #    self.assertRaises(IOError, sys.stdin.seek, -1)
+        #else:
+        #    print((
+        #        '  Skipping sys.stdin.seek(-1), it may crash the interpreter.'
+        #        ' Test manually.'), file=sys.__stdout__)
+        #self.assertRaises(IOError, sys.stdin.truncate)
+        # XXX Comment this out since sys.stdin is currently an old style file 
+        pass
+
+    def testUnicodeOpen(self):
+        # verify repr works for unicode too
+        f = _fileio._FileIO(unicode(TESTFN), "w")
+        # XXX doesn't work yet:
+        ##self.assert_(repr(f).startswith("<open file u'" + TESTFN))
+        f.close()
+        os.unlink(TESTFN)
+
+    def testBadModeArgument(self):
+        # verify that we get a sensible error message for bad mode argument
+        bad_mode = "qwerty"
+        try:
+            f = _fileio._FileIO(TESTFN, bad_mode)
+        except ValueError as msg:
+            if msg.message != 0:
+                s = str(msg)
+                if s.find(TESTFN) != -1 or s.find(bad_mode) == -1:
+                    self.fail("bad error message for invalid mode: %s" % s)
+            # if msg[0] == 0, we're probably on Windows where there may be
+            # no obvious way to discover why open() failed.
+        else:
+            f.close()
+            self.fail("no error for invalid mode: %s" % bad_mode)
+
+    def testTruncateOnWindows(self):
+        def bug801631():
+            # SF bug <http://www.python.org/sf/801631>
+            # "file.truncate fault on windows"
+            f = _fileio._FileIO(TESTFN, 'w')
+            f.write(bytes(range(11)))
+            f.close()
+
+            f = _fileio._FileIO(TESTFN,'r+')
+            data = f.read(5)
+            if data != bytes(range(5)):
+                self.fail("Read on file opened for update failed %r" % data)
+            if f.tell() != 5:
+                self.fail("File pos after read wrong %d" % f.tell())
+
+            f.truncate()
+            if f.tell() != 5:
+                self.fail("File pos after ftruncate wrong %d" % f.tell())
+
+            f.close()
+            size = os.path.getsize(TESTFN)
+            if size != 5:
+                self.fail("File size after ftruncate wrong %d" % size)
+
+        try:
+            bug801631()
+        finally:
+            os.unlink(TESTFN)
+
+def test_main():
+    # Historically, these tests have been sloppy about removing TESTFN.
+    # So get rid of it no matter what.
+    try:
+        run_unittest(AutoFileTests, OtherFileTests)
+    finally:
+        if os.path.exists(TESTFN):
+            os.unlink(TESTFN)
+
+if __name__ == '__main__':
+    test_main()

Lib/test/test_io.py

@@ -5,7 +5,9 @@ from test import test_support
 
 import io
 
+
 class MockIO(io.RawIOBase):
+
     def __init__(self, readStack=()):
         self._readStack = list(readStack)
         self._writeStack = []
@@ -38,10 +40,13 @@ class MockIO(io.RawIOBase):
     def tell(self):
         return 42
 
+
 class MockNonBlockWriterIO(io.RawIOBase):
+
     def __init__(self, blockingScript):
         self.bs = list(blockingScript)
         self._write_stack = []
+
     def write(self, b):
         self._write_stack.append(b)
         n = self.bs.pop(0)
@@ -49,9 +54,11 @@ class MockNonBlockWriterIO(io.RawIOBase):
             raise io.BlockingIO(0, "test blocking", -n)
         else:
             return n
+
     def writable(self):
         return True
 
+
 class IOTest(unittest.TestCase):
 
     def tearDown(self):
@@ -110,7 +117,38 @@ class IOTest(unittest.TestCase):
         f = io.BytesIO(data)
         self.read_ops(f)
 
+    def test_fileio_FileIO(self):
+        import _fileio
+        f = _fileio._FileIO(test_support.TESTFN, "w")
+        self.assertEqual(f.readable(), False)
+        self.assertEqual(f.writable(), True)
+        self.assertEqual(f.seekable(), True)
+        self.write_ops(f)
+        f.close()
+        f = _fileio._FileIO(test_support.TESTFN, "r")
+        self.assertEqual(f.readable(), True)
+        self.assertEqual(f.writable(), False)
+        self.assertEqual(f.seekable(), True)
+        self.read_ops(f)
+        f.close()
+
+    def test_PyFileIO(self):
+        f = io._PyFileIO(test_support.TESTFN, "w")
+        self.assertEqual(f.readable(), False)
+        self.assertEqual(f.writable(), True)
+        self.assertEqual(f.seekable(), True)
+        self.write_ops(f)
+        f.close()
+        f = io._PyFileIO(test_support.TESTFN, "r")
+        self.assertEqual(f.readable(), True)
+        self.assertEqual(f.writable(), False)
+        self.assertEqual(f.seekable(), True)
+        self.read_ops(f)
+        f.close()
+
+
 class BytesIOTest(unittest.TestCase):
+
     def testInit(self):
         buf = b"1234567890"
         bytesIo = io.BytesIO(buf)
@@ -152,7 +190,9 @@ class BytesIOTest(unittest.TestCase):
         bytesIo.seek(10000)
         self.assertEquals(10000, bytesIo.tell())
 
+
 class BufferedReaderTest(unittest.TestCase):
+
     def testRead(self):
         rawIo = MockIO((b"abc", b"d", b"efg"))
         bufIo = io.BufferedReader(rawIo)
@@ -193,7 +233,9 @@ class BufferedReaderTest(unittest.TestCase):
         # this test. Else, write it.
         pass
 
+
 class BufferedWriterTest(unittest.TestCase):
+
     def testWrite(self):
         # Write to the buffered IO but don't overflow the buffer.
         writer = MockIO()
@@ -246,7 +288,9 @@ class BufferedWriterTest(unittest.TestCase):
 
         self.assertEquals(b"abc", writer._writeStack[0])
 
+
 class BufferedRWPairTest(unittest.TestCase):
+
     def testRWPair(self):
         r = MockIO(())
         w = MockIO()
@@ -254,7 +298,9 @@ class BufferedRWPairTest(unittest.TestCase):
 
         # XXX need implementation
 
+
 class BufferedRandom(unittest.TestCase):
+
     def testReadAndWrite(self):
         raw = MockIO((b"asdf", b"ghjk"))
         rw = io.BufferedRandom(raw, 8, 12)

setup.py

@@ -1037,6 +1037,9 @@ class PyBuildExt(build_ext):
         # Thomas Heller's _ctypes module
         self.detect_ctypes(inc_dirs, lib_dirs)
 
+        # _fileio -- supposedly cross platform
+        exts.append(Extension('_fileio', ['_fileio.c']))
+
         # Platform-specific libraries
         if platform == 'linux2':
             # Linux-specific modules