[Python-checkins] r68683 - in python/branches/io-c: Lib/io.py Modules/Setup.dist Modules/_bufferedio.c Modules/_bytesio.c Modules/_fileio.c Modules/_iobase.c Modules/_iomodule.h Modules/_textio.c Modules/io.c setup.py

antoine.pitrou python-checkins at python.org
Sun Jan 18 00:13:50 CET 2009


Author: antoine.pitrou
Date: Sun Jan 18 00:13:48 2009
New Revision: 68683

Log:
Merge in changes from the io-c sandbox. Tests will follow in separate commits.



Added:
   python/branches/io-c/Modules/_bufferedio.c   (contents, props changed)
   python/branches/io-c/Modules/_iobase.c   (contents, props changed)
   python/branches/io-c/Modules/_iomodule.h   (contents, props changed)
   python/branches/io-c/Modules/_textio.c   (contents, props changed)
   python/branches/io-c/Modules/io.c   (contents, props changed)
Modified:
   python/branches/io-c/Lib/io.py
   python/branches/io-c/Modules/Setup.dist
   python/branches/io-c/Modules/_bytesio.c
   python/branches/io-c/Modules/_fileio.c
   python/branches/io-c/setup.py

Modified: python/branches/io-c/Lib/io.py
==============================================================================
--- python/branches/io-c/Lib/io.py	(original)
+++ python/branches/io-c/Lib/io.py	Sun Jan 18 00:13:48 2009
@@ -58,7 +58,7 @@
 import os
 import abc
 import codecs
-import _fileio
+#import _fileio
 # Import _thread instead of threading to reduce startup cost
 try:
     from _thread import allocate_lock as Lock
@@ -70,7 +70,7 @@
 DEFAULT_BUFFER_SIZE = 8 * 1024  # bytes
 
 
-class BlockingIOError(IOError):
+class unused_BlockingIOError(IOError):
 
     """Exception raised when I/O would block on a non-blocking I/O stream."""
 
@@ -79,7 +79,7 @@
         self.characters_written = characters_written
 
 
-def open(file, mode="r", buffering=None, encoding=None, errors=None,
+def unused_open(file, mode="r", buffering=None, encoding=None, errors=None,
          newline=None, closefd=True):
 
     r"""Open file and return a stream.  Raise IOError upon failure.
@@ -254,8 +254,12 @@
     text = TextIOWrapper(buffer, encoding, errors, newline, line_buffering)
     text.mode = mode
     return text
+import _io
+BlockingIOError = _io.BlockingIOError
+UnsupportedOperation = _io.UnsupportedOperation
+open = _io.open
 
-class _DocDescriptor:
+class unused_DocDescriptor:
     """Helper for builtins.open.__doc__
     """
     def __get__(self, obj, typ):
@@ -264,7 +268,7 @@
                  "errors=None, newline=None, closefd=True)\n\n" +
             open.__doc__)
 
-class OpenWrapper:
+class unused_OpenWrapper:
     """Wrapper for builtins.open
 
     Trick so that open won't become a bound method when stored
@@ -272,17 +276,18 @@
 
     See initstdio() in Python/pythonrun.c.
     """
-    __doc__ = _DocDescriptor()
+    __doc__ = unused_DocDescriptor()
 
     def __new__(cls, *args, **kwargs):
         return open(*args, **kwargs)
+OpenWrapper = _io.open
 
 
-class UnsupportedOperation(ValueError, IOError):
+class unused_UnsupportedOperation(ValueError, IOError):
     pass
 
 
-class IOBase(metaclass=abc.ABCMeta):
+class unused_IOBase(metaclass=abc.ABCMeta):
 
     """The abstract base class for all I/O classes, acting on streams of
     bytes. There is no public constructor.
@@ -340,7 +345,6 @@
 
     def tell(self) -> int:
         """Return current stream position."""
-        self._checkClosed()
         return self.seek(0, 1)
 
     def truncate(self, pos: int = None) -> int:
@@ -359,8 +363,6 @@
         This is not implemented for read-only and non-blocking streams.
         """
         # XXX Should this return the number of bytes written???
-        if self.__closed:
-            raise ValueError("I/O operation on closed file.")
 
     __closed = False
 
@@ -533,7 +535,6 @@
         lines will be read if the total size (in bytes/characters) of all
         lines so far exceeds hint.
         """
-        self._checkClosed()
         if hint is None or hint <= 0:
             return list(self)
         n = 0
@@ -549,9 +550,10 @@
         self._checkClosed()
         for line in lines:
             self.write(line)
+IOBase = _io.IOBase
 
 
-class RawIOBase(IOBase):
+class unused_RawIOBase(IOBase):
 
     """Base class for raw binary I/O."""
 
@@ -571,7 +573,6 @@
         Returns an empty bytes object on EOF, or None if the object is
         set not to block and has no data to read.
         """
-        self._checkClosed()
         if n is None:
             n = -1
         if n < 0:
@@ -583,7 +584,6 @@
 
     def readall(self):
         """Read until EOF, using multiple read() call."""
-        self._checkClosed()
         res = bytearray()
         while True:
             data = self.read(DEFAULT_BUFFER_SIZE)
@@ -606,31 +606,35 @@
         Returns the number of bytes written, which may be less than len(b).
         """
         self._unsupported("write")
+RawIOBase = _io.RawIOBase
 
 
-class FileIO(_fileio._FileIO, RawIOBase):
+if 0:
+    class unused_FileIO(_fileio._FileIO, RawIOBase):
 
-    """Raw I/O implementation for OS files."""
+        """Raw I/O implementation for OS files."""
 
-    # This multiply inherits from _FileIO and RawIOBase to make
-    # isinstance(io.FileIO(), io.RawIOBase) return True without requiring
-    # that _fileio._FileIO inherits from io.RawIOBase (which would be hard
-    # to do since _fileio.c is written in C).
-
-    def __init__(self, name, mode="r", closefd=True):
-        _fileio._FileIO.__init__(self, name, mode, closefd)
-        self._name = name
+        # This multiply inherits from _FileIO and RawIOBase to make
+        # isinstance(io.FileIO(), io.RawIOBase) return True without requiring
+        # that _fileio._FileIO inherits from io.RawIOBase (which would be hard
+        # to do since _fileio.c is written in C).
 
-    def close(self):
-        _fileio._FileIO.close(self)
-        RawIOBase.close(self)
+        def __init__(self, name, mode="r", closefd=True):
+            _fileio._FileIO.__init__(self, name, mode, closefd)
+            self._name = name
 
-    @property
-    def name(self):
-        return self._name
+        def close(self):
+            _fileio._FileIO.close(self)
+            RawIOBase.close(self)
+
+        @property
+        def name(self):
+            return self._name
+
+FileIO = _io.FileIO
 
 
-class BufferedIOBase(IOBase):
+class unused_BufferedIOBase(IOBase):
 
     """Base class for buffered IO objects.
 
@@ -679,7 +683,6 @@
         data at the moment.
         """
         # XXX This ought to work with anything that supports the buffer API
-        self._checkClosed()
         data = self.read(len(b))
         n = len(data)
         try:
@@ -701,9 +704,10 @@
         underlying raw stream cannot accept more data at the moment.
         """
         self._unsupported("write")
+BufferedIOBase = _io.BufferedIOBase
 
 
-class _BufferedIOMixin(BufferedIOBase):
+class unused_BufferedIOMixin(BufferedIOBase):
 
     """A mixin implementation of BufferedIOBase with an underlying raw stream.
 
@@ -780,7 +784,7 @@
         return self.raw.isatty()
 
 
-class _BytesIO(BufferedIOBase):
+class unused_BytesIO(BufferedIOBase):
 
     """Buffered I/O implementation using an in-memory bytes buffer."""
 
@@ -794,11 +798,13 @@
     def getvalue(self):
         """Return the bytes value (contents) of the buffer
         """
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("getvalue on closed file")
         return bytes(self._buffer)
 
     def read(self, n=None):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("read from closed file")
         if n is None:
             n = -1
         if n < 0:
@@ -816,7 +822,8 @@
         return self.read(n)
 
     def write(self, b):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("write to closed file")
         if isinstance(b, str):
             raise TypeError("can't write str to binary stream")
         n = len(b)
@@ -833,7 +840,8 @@
         return n
 
     def seek(self, pos, whence=0):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("seek on closed file")
         try:
             pos = pos.__index__()
         except AttributeError as err:
@@ -851,11 +859,13 @@
         return self._pos
 
     def tell(self):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("tell on closed file")
         return self._pos
 
     def truncate(self, pos=None):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("truncate on closed file")
         if pos is None:
             pos = self._pos
         elif pos < 0:
@@ -873,17 +883,19 @@
         return True
 
 # Use the faster implementation of BytesIO if available
-try:
-    import _bytesio
+if 0:
+    try:
+        import _bytesio
 
-    class BytesIO(_bytesio._BytesIO, BufferedIOBase):
-        __doc__ = _bytesio._BytesIO.__doc__
+        class BytesIO(_bytesio._BytesIO, BufferedIOBase):
+            __doc__ = _bytesio._BytesIO.__doc__
 
-except ImportError:
-    BytesIO = _BytesIO
+    except ImportError:
+        BytesIO = _BytesIO
+BytesIO = _io.BytesIO
 
 
-class BufferedReader(_BufferedIOMixin):
+class unused_BufferedReader(unused_BufferedIOMixin):
 
     """BufferedReader(raw[, buffer_size])
 
@@ -915,7 +927,6 @@
         mode. If n is negative, read until EOF or until read() would
         block.
         """
-        self._checkClosed()
         with self._read_lock:
             return self._read_unlocked(n)
 
@@ -972,7 +983,6 @@
         do at most one raw read to satisfy it.  We never return more
         than self.buffer_size.
         """
-        self._checkClosed()
         with self._read_lock:
             return self._peek_unlocked(n)
 
@@ -991,7 +1001,6 @@
         """Reads up to n bytes, with at most one read() system call."""
         # Returns up to n bytes.  If at least one byte is buffered, we
         # only return buffered bytes.  Otherwise, we do one raw read.
-        self._checkClosed()
         if n <= 0:
             return b""
         with self._read_lock:
@@ -1000,20 +1009,19 @@
                 min(n, len(self._read_buf) - self._read_pos))
 
     def tell(self):
-        self._checkClosed()
         return self.raw.tell() - len(self._read_buf) + self._read_pos
 
     def seek(self, pos, whence=0):
-        self._checkClosed()
         with self._read_lock:
             if whence == 1:
                 pos -= len(self._read_buf) - self._read_pos
             pos = self.raw.seek(pos, whence)
             self._reset_read_buf()
             return pos
+BufferedReader = _io.BufferedReader
 
 
-class BufferedWriter(_BufferedIOMixin):
+class unused_BufferedWriter(unused_BufferedIOMixin):
 
     """A buffer for a writeable sequential RawIO object.
 
@@ -1035,7 +1043,8 @@
         self._write_lock = Lock()
 
     def write(self, b):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("write to closed file")
         if isinstance(b, str):
             raise TypeError("can't write str to binary stream")
         with self._write_lock:
@@ -1065,7 +1074,6 @@
             return written
 
     def truncate(self, pos=None):
-        self._checkClosed()
         with self._write_lock:
             self._flush_unlocked()
             if pos is None:
@@ -1073,11 +1081,12 @@
             return self.raw.truncate(pos)
 
     def flush(self):
-        self._checkClosed()
         with self._write_lock:
             self._flush_unlocked()
 
     def _flush_unlocked(self):
+        if self.closed:
+            raise ValueError("flush of closed file")
         written = 0
         try:
             while self._write_buf:
@@ -1091,17 +1100,16 @@
             raise BlockingIOError(e.errno, e.strerror, written)
 
     def tell(self):
-        self._checkClosed()
         return self.raw.tell() + len(self._write_buf)
 
     def seek(self, pos, whence=0):
-        self._checkClosed()
         with self._write_lock:
             self._flush_unlocked()
             return self.raw.seek(pos, whence)
+BufferedWriter = _io.BufferedWriter
 
 
-class BufferedRWPair(BufferedIOBase):
+class unused_BufferedRWPair(BufferedIOBase):
 
     """A buffered reader and writer object together.
 
@@ -1164,10 +1172,10 @@
 
     @property
     def closed(self):
-        return self.writer.closed
-
+        return self.writer.closed()
+BufferedRWPair = _io.BufferedRWPair
 
-class BufferedRandom(BufferedWriter, BufferedReader):
+class unused_BufferedRandom(unused_BufferedWriter, unused_BufferedReader):
 
     """A buffered interface to random access streams.
 
@@ -1193,7 +1201,6 @@
         return pos
 
     def tell(self):
-        self._checkClosed()
         if self._write_buf:
             return self.raw.tell() + len(self._write_buf)
         else:
@@ -1225,13 +1232,13 @@
         return BufferedReader.read1(self, n)
 
     def write(self, b):
-        self._checkClosed()
         if self._read_buf:
             # Undo readahead
             with self._read_lock:
                 self.raw.seek(self._read_pos - len(self._read_buf), 1)
                 self._reset_read_buf()
         return BufferedWriter.write(self, b)
+BufferedRandom = _io.BufferedRandom
 
 
 class TextIOBase(IOBase):
@@ -1282,7 +1289,8 @@
         return None
 
 
-class IncrementalNewlineDecoder(codecs.IncrementalDecoder):
+IncrementalNewlineDecoder = _io.IncrementalNewlineDecoder
+class unused_IncrementalNewlineDecoder(codecs.IncrementalDecoder):
     r"""Codec used when reading a file in universal newlines mode.  It wraps
     another incremental decoder, translating \r\n and \r into \n.  It also
     records the types of newlines encountered.  When used with
@@ -1358,7 +1366,8 @@
                )[self.seennl]
 
 
-class TextIOWrapper(TextIOBase):
+TextIOWrapper = _io.TextIOWrapper
+class unusedTextIOWrapper(TextIOBase):
 
     r"""Character and line based layer over a BufferedIOBase object, buffer.
 
@@ -1382,7 +1391,7 @@
     write contains a newline character.
     """
 
-    _CHUNK_SIZE = 2048
+    _CHUNK_SIZE = 128
 
     def __init__(self, buffer, encoding=None, errors=None, newline=None,
                  line_buffering=False):
@@ -1483,7 +1492,8 @@
         return self.buffer.isatty()
 
     def write(self, s: str):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("write to closed file")
         if not isinstance(s, str):
             raise TypeError("can't write %s to text stream" %
                             s.__class__.__name__)
@@ -1591,7 +1601,6 @@
         return position, dec_flags, bytes_to_feed, need_eof, chars_to_skip
 
     def tell(self):
-        self._checkClosed()
         if not self._seekable:
             raise IOError("underlying stream is not seekable")
         if not self._telling:
@@ -1662,7 +1671,8 @@
         return self.buffer.truncate()
 
     def seek(self, cookie, whence=0):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("tell on closed file")
         if not self._seekable:
             raise IOError("underlying stream is not seekable")
         if whence == 1: # seek relative to current position
@@ -1720,7 +1730,6 @@
         return cookie
 
     def read(self, n=None):
-        self._checkClosed()
         if n is None:
             n = -1
         decoder = self._decoder or self._get_decoder()
@@ -1741,7 +1750,6 @@
             return result
 
     def __next__(self):
-        self._checkClosed()
         self._telling = False
         line = self.readline()
         if not line:
@@ -1751,7 +1759,8 @@
         return line
 
     def readline(self, limit=None):
-        self._checkClosed()
+        if self.closed:
+            raise ValueError("read from closed file")
         if limit is None:
             limit = -1
 
@@ -1838,7 +1847,7 @@
     def newlines(self):
         return self._decoder.newlines if self._decoder else None
 
-class _StringIO(TextIOWrapper):
+class unused_StringIO(TextIOWrapper):
     """Text I/O implementation using an in-memory buffer.
 
     The initial_value argument sets the value of object.  The newline
@@ -1972,7 +1981,8 @@
 
         def getvalue(self) -> str:
             """Retrieve the entire contents of the object."""
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("read on closed file")
             return self._getvalue()
 
         def write(self, s: str) -> int:
@@ -1980,7 +1990,8 @@
 
             Returns the number of characters written.
             """
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("write to closed file")
             if not isinstance(s, str):
                 raise TypeError("can't write %s to text stream" %
                                 s.__class__.__name__)
@@ -1997,7 +2008,8 @@
             If the argument is negative or omitted, read until EOF
             is reached. Return an empty string at EOF.
             """
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("read to closed file")
             if n is None:
                 n = -1
             res = self._pending
@@ -2012,7 +2024,8 @@
 
         def tell(self) -> int:
             """Tell the current file position."""
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("tell from closed file")
             if self._pending:
                 return self._tell() - len(self._pending)
             else:
@@ -2027,7 +2040,8 @@
                 2  End of stream - pos must be 0.
             Returns the new absolute position.
             """
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("seek from closed file")
             self._pending = ""
             return self._seek(pos, whence)
 
@@ -2038,12 +2052,14 @@
             returned by tell().  Imply an absolute seek to pos.
             Returns the new absolute position.
             """
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("truncate from closed file")
             self._pending = ""
             return self._truncate(pos)
 
         def readline(self, limit: int = None) -> str:
-            self._checkClosed()
+            if self.closed:
+                raise ValueError("read from closed file")
             if limit is None:
                 limit = -1
             if limit >= 0:
@@ -2138,3 +2154,7 @@
 
 except ImportError:
     StringIO = _StringIO
+
+# make test_memoryio happy!
+_BytesIO = BytesIO
+_StringIO = StringIO

Modified: python/branches/io-c/Modules/Setup.dist
==============================================================================
--- python/branches/io-c/Modules/Setup.dist	(original)
+++ python/branches/io-c/Modules/Setup.dist	Sun Jan 18 00:13:48 2009
@@ -111,10 +111,11 @@
 				# if $HOME is not set
 _sre _sre.c			# Fredrik Lundh's new regular expressions
 _codecs _codecsmodule.c		# access to the builtin codecs and codec registry
-_fileio _fileio.c		# Standard I/O baseline
 _weakref _weakref.c		# weak references
-_bytesio _bytesio.c		# For Lib/io.py
-_stringio _stringio.c		# For Lib/io.py
+
+# Standard I/O baseline
+_io io.c _iobase.c _fileio.c _bytesio.c _bufferedio.c _textio.c
+_stringio _stringio.c
 
 # The zipimport module is always imported at startup. Having it as a
 # builtin module avoids some bootstrapping problems and reduces overhead.
@@ -164,7 +165,6 @@
 #_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
-#_functools _functoolsmodule.c	# Tools for working with functions and callable objects
 #_elementtree -I$(srcdir)/Modules/expat -DHAVE_EXPAT_CONFIG_H -DUSE_PYEXPAT_CAPI _elementtree.c	# elementtree accelerator
 #_pickle _pickle.c	# pickle accelerator
 #datetime datetimemodule.c	# date/time type

Added: python/branches/io-c/Modules/_bufferedio.c
==============================================================================
--- (empty file)
+++ python/branches/io-c/Modules/_bufferedio.c	Sun Jan 18 00:13:48 2009
@@ -0,0 +1,1904 @@
+#include "Python.h"
+#include "structmember.h"
+#include "pythread.h"
+#include "_iomodule.h"
+
+/*
+ * BufferedIOBase class, inherits from IOBase.
+ */
+PyDoc_STRVAR(BufferedIOBase_doc,
+    "Base class for buffered IO objects.\n"
+    "\n"
+    "The main difference with RawIOBase is that the read() method\n"
+    "supports omitting the size argument, and does not have a default\n"
+    "implementation that defers to readinto().\n"
+    "\n"
+    "In addition, read(), readinto() and write() may raise\n"
+    "BlockingIOError if the underlying raw stream is in non-blocking\n"
+    "mode and not ready; unlike their raw counterparts, they will never\n"
+    "return None.\n"
+    "\n"
+    "A typical implementation should not inherit from a RawIOBase\n"
+    "implementation, but wrap one.\n"
+    );
+
+static PyObject *
+BufferedIOBase_readinto(PyObject *self, PyObject *args)
+{
+    Py_buffer buf;
+    Py_ssize_t len;
+    PyObject *data;
+
+    if (!PyArg_ParseTuple(args, "w*:readinto", &buf)) {
+        return NULL;
+    }
+
+    data = PyObject_CallMethod(self, "read", "n", buf.len);
+    if (data == NULL)
+        goto error;
+
+    if (!PyBytes_Check(data)) {
+        Py_DECREF(data);
+        PyErr_SetString(PyExc_TypeError, "read() should return bytes");
+        goto error;
+    }
+
+    len = Py_SIZE(data);
+    memcpy(buf.buf, PyBytes_AS_STRING(data), len);
+
+    PyBuffer_Release(&buf);
+    Py_DECREF(data);
+
+    return PyLong_FromSsize_t(len);
+
+  error:
+    PyBuffer_Release(&buf);
+    return NULL;
+}
+
+static PyMethodDef BufferedIOBase_methods[] = {
+    {"readinto", BufferedIOBase_readinto, METH_VARARGS},
+    {NULL, NULL}
+};
+
+PyTypeObject PyBufferedIOBase_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "BufferedIOBase",           /*tp_name*/
+    0,                          /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    0,                          /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    BufferedIOBase_doc,         /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    0,                          /* tp_weaklistoffset */
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    BufferedIOBase_methods,     /* tp_methods */
+    0,                          /* tp_members */
+    0,                          /* tp_getset */
+    &PyIOBase_Type,             /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    0,                          /* tp_dictoffset */
+    0,                          /* tp_init */
+    0,                          /* tp_alloc */
+    0,                          /* tp_new */
+};
+
+
+typedef struct {
+    PyObject_HEAD
+
+    PyObject *raw;
+    int ok;    /* Initialized? */
+    int readable;
+    int writable;
+
+    /* Absolute position inside the raw stream (-1 if unknown). */
+    Py_off_t abs_pos;
+
+    /* A static buffer of size `buffer_size` */
+    char *buffer;
+    /* Current logical position in the buffer. */
+    Py_off_t pos;
+    /* Position of the raw stream in the buffer. */
+    Py_off_t raw_pos;
+
+    /* Just after the last buffered byte in the buffer, or -1 if the buffer
+       isn't ready for reading. */
+    Py_off_t read_end;
+
+    /* Just after the last byte actually written */
+    Py_off_t write_pos;
+    /* Just after the last byte waiting to be written, or -1 if the buffer
+       isn't ready for writing. */
+    Py_off_t write_end;
+
+    PyThread_type_lock lock;
+
+    Py_ssize_t buffer_size;
+    Py_ssize_t buffer_mask;
+
+    PyObject *dict;
+    PyObject *weakreflist;
+} BufferedObject;
+
+/*
+    Implementation notes:
+    
+    * BufferedReader, BufferedWriter and BufferedRandom try to share most
+      methods (this is helped by the members `readable` and `writable`, which
+      are initialized in the respective constructors)
+    * They also share a single buffer for reading and writing. This enables
+      interleaved reads and writes without flushing. It also makes the logic
+      a bit trickier to get right.
+    * The absolute position of the raw stream is cached, if possible, in the
+      `abs_pos` member. It must be updated every time an operation is done
+      on the raw stream. If not sure, it can be reinitialized by calling
+      _Buffered_raw_tell(), which queries the raw stream (_Buffered_raw_seek()
+      also does it). To read it, use RAW_TELL().
+    * Three helpers, _BufferedReader_raw_read, _BufferedWriter_raw_write and
+      _BufferedWriter_flush_unlocked do a lot of useful housekeeping.
+
+    NOTE: we should try to maintain block alignment of reads and writes to the
+    raw stream (according to the buffer size), but for now it is only done
+    in read() and friends.
+    
+    XXX: method naming is a bit messy.
+*/
+
+/* These macros protect the BufferedObject against concurrent operations. */
+
+#define ENTER_BUFFERED(self) \
+    Py_BEGIN_ALLOW_THREADS \
+    PyThread_acquire_lock(self->lock, 1); \
+    Py_END_ALLOW_THREADS
+
+#define LEAVE_BUFFERED(self) \
+    PyThread_release_lock(self->lock);
+
+#define CHECK_INITIALIZED(self) \
+    if (self->ok <= 0) { \
+        PyErr_SetString(PyExc_ValueError, \
+            "I/O operation on uninitialized object"); \
+        return NULL; \
+    }
+
+#define CHECK_INITIALIZED_INT(self) \
+    if (self->ok <= 0) { \
+        PyErr_SetString(PyExc_ValueError, \
+            "I/O operation on uninitialized object"); \
+        return -1; \
+    }
+
+#define VALID_READ_BUFFER(self) \
+    (self->readable && self->read_end != -1)
+
+#define VALID_WRITE_BUFFER(self) \
+    (self->writable && self->write_end != -1)
+
+#define ADJUST_POSITION(self, _new_pos) \
+    do { \
+        self->pos = _new_pos; \
+        if (VALID_READ_BUFFER(self) && self->read_end < self->pos) \
+            self->read_end = self->pos; \
+    } while(0)
+
+#define READAHEAD(self) \
+    ((self->readable && VALID_READ_BUFFER(self)) \
+        ? (self->read_end - self->pos) : 0)
+
+#define RAW_OFFSET(self) \
+    (((VALID_READ_BUFFER(self) || VALID_WRITE_BUFFER(self)) \
+        && self->raw_pos >= 0) ? self->raw_pos - self->pos : 0)
+
+#define RAW_TELL(self) \
+    (self->abs_pos != -1 ? self->abs_pos : _Buffered_raw_tell(self))
+
+#define MINUS_LAST_BLOCK(self, size) \
+    (self->buffer_mask ? \
+        (size & ~self->buffer_mask) : \
+        (self->buffer_size * (size / self->buffer_size)))
+
+
+static void
+BufferedObject_dealloc(BufferedObject *self)
+{
+    PyObject *res;
+    /* XXX this is inelegant */
+    if (Py_TYPE(self)->tp_del == NULL) {
+        PyObject *tp, *v, *tb;
+        PyErr_Fetch(&tp, &v, &tb);
+        /* We need to resurrect the object as calling close() can invoke
+           arbitrary code. */
+        ((PyObject *) self)->ob_refcnt++;
+        res = PyObject_CallMethodObjArgs((PyObject *) self, _PyIO_str_close,
+                                          NULL);
+        if (res == NULL) {
+            /* XXX dump exception on terminal?
+               But IOBase.__del__ prefers to remain silent... */
+            PyErr_Clear();
+        }
+        Py_XDECREF(res);
+        PyErr_Restore(tp, v, tb);
+        if (--((PyObject *) self)->ob_refcnt != 0)
+            return;
+    }
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs((PyObject *)self);
+    Py_CLEAR(self->raw);
+    if (self->buffer) {
+        PyMem_Free(self->buffer);
+        self->buffer = NULL;
+    }
+    if (self->lock) {
+        PyThread_free_lock(self->lock);
+        self->lock = NULL;
+    }
+    Py_CLEAR(self->dict);
+    Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+
+/*
+ * _BufferedIOMixin methods
+ * This is not a class, just a collection of methods that will be reused
+ * by BufferedReader and BufferedWriter
+ */
+
+/* Positioning */
+
+static PyObject *
+BufferedIOMixin_truncate(BufferedObject *self, PyObject *args)
+{
+    PyObject *pos = Py_None;
+    PyObject *res;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "|O:truncate", &pos)) {
+        return NULL;
+    }
+
+    /* Flush the stream.  We're mixing buffered I/O with lower-level I/O,
+     * and a flush may be necessary to synch both views of the current
+     *  file state.
+     */
+    /* FIXME: raw objects don't have flush()
+     */
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_flush, NULL);
+    if (res == NULL)
+        return NULL;
+    Py_DECREF(res);
+
+    if (pos == Py_None)
+        pos = PyObject_CallMethod(self->raw, "tell", NULL);
+    else
+        Py_INCREF(pos);
+
+    /* XXX: Should seek() be used, instead of passing the position
+     * XXX  directly to truncate?
+     */
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_truncate, pos, NULL);
+    Py_DECREF(pos);
+
+    return res;
+}
+
+/* Flush and close */
+
+static PyObject *
+BufferedIOMixin_flush(BufferedObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_flush, NULL);
+}
+
+static int
+BufferedIOMixin_closed(BufferedObject *self)
+{
+    int closed;
+    PyObject *res;
+    CHECK_INITIALIZED_INT(self)
+    res = PyObject_GetAttr(self->raw, _PyIO_str_closed);
+    if (res == NULL)
+        return -1;
+    closed = PyObject_IsTrue(res);
+    Py_DECREF(res);
+    return closed;
+}
+
+static PyObject *
+BufferedIOMixin_closed_get(BufferedObject *self, void *context)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_GetAttr(self->raw, _PyIO_str_closed);
+}
+
+static PyObject *
+BufferedIOMixin_close(BufferedObject *self, PyObject *args)
+{
+    PyObject *res = NULL;
+    int r;
+
+    CHECK_INITIALIZED(self)
+    ENTER_BUFFERED(self)
+
+    r = BufferedIOMixin_closed(self);
+    if (r < 0)
+        goto end;
+    if (r > 0) {
+        res = Py_None;
+        Py_INCREF(res);
+        goto end;
+    }
+    /* flush() will most probably re-take the lock, so drop it first */
+    LEAVE_BUFFERED(self)
+    res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
+    ENTER_BUFFERED(self)
+    if (res == NULL) {
+        /* If flush() fails, just give up */
+        if (PyErr_ExceptionMatches(PyExc_IOError))
+            PyErr_Clear();
+        else
+            goto end;
+    }
+    Py_XDECREF(res);
+
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_close, NULL);
+
+end:
+    LEAVE_BUFFERED(self)
+    return res;
+}
+
+/* Inquiries */
+
+static PyObject *
+BufferedIOMixin_seekable(BufferedObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_seekable, NULL);
+}
+
+static PyObject *
+BufferedIOMixin_readable(BufferedObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_readable, NULL);
+}
+
+static PyObject *
+BufferedIOMixin_writable(BufferedObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_writable, NULL);
+}
+
+static PyObject *
+BufferedIOMixin_name_get(BufferedObject *self, void *context)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_GetAttrString(self->raw, "name");
+}
+
+static PyObject *
+BufferedIOMixin_mode_get(BufferedObject *self, void *context)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_GetAttrString(self->raw, "mode");
+}
+
+/* Lower-level APIs */
+
+static PyObject *
+BufferedIOMixin_fileno(BufferedObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_fileno, NULL);
+}
+
+static PyObject *
+BufferedIOMixin_isatty(BufferedObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self)
+    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_isatty, NULL);
+}
+
+
+/* Forward decls */
+static PyObject *
+_BufferedWriter_flush_unlocked(BufferedObject *, int);
+static Py_ssize_t
+_BufferedReader_fill_buffer(BufferedObject *self);
+static void
+_BufferedReader_reset_buf(BufferedObject *self);
+static void
+_BufferedWriter_reset_buf(BufferedObject *self);
+static PyObject *
+_BufferedReader_peek_unlocked(BufferedObject *self, Py_ssize_t);
+static PyObject *
+_BufferedReader_read_unlocked(BufferedObject *self, Py_ssize_t);
+
+
+/*
+ * Helpers
+ */
+
+/* Returns the address of the `written` member if a BlockingIOError was
+   raised, NULL otherwise. The error is always re-raised. */
+static Py_ssize_t *
+_Buffered_check_blocking_error(void)
+{
+    PyObject *t, *v, *tb;
+    PyBlockingIOErrorObject *err;
+
+    PyErr_Fetch(&t, &v, &tb);
+    if (v == NULL || !PyErr_GivenExceptionMatches(v, PyExc_BlockingIOError)) {
+        PyErr_Restore(t, v, tb);
+        return NULL;
+    }
+    err = (PyBlockingIOErrorObject *) v;
+    /* TODO: sanity check (err->written >= 0) */
+    PyErr_Restore(t, v, tb);
+    return &err->written;
+}
+
+static Py_off_t
+_Buffered_raw_tell(BufferedObject *self)
+{
+    PyObject *res;
+    Py_off_t n;
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_tell, NULL);
+    if (res == NULL)
+        return -1;
+    n = PyNumber_AsOff_t(res, PyExc_ValueError);
+    Py_DECREF(res);
+    if (n < 0) {
+        if (!PyErr_Occurred())
+            PyErr_Format(PyExc_IOError,
+                         "Raw stream returned invalid position %zd", n);
+        return -1;
+    }
+    self->abs_pos = n;
+    return n;
+}
+
+static Py_off_t
+_Buffered_raw_seek(BufferedObject *self, Py_off_t target, int whence)
+{
+    PyObject *res, *posobj, *whenceobj;
+    Py_off_t n;
+
+    posobj = PyLong_FromOff_t(target);
+    if (posobj == NULL)
+        return -1;
+    whenceobj = PyLong_FromLong(whence);
+    if (whenceobj == NULL) {
+        Py_DECREF(posobj);
+        return -1;
+    }
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_seek,
+                                     posobj, whenceobj, NULL);
+    Py_DECREF(posobj);
+    Py_DECREF(whenceobj);
+    if (res == NULL)
+        return -1;
+    n = PyNumber_AsOff_t(res, PyExc_ValueError);
+    Py_DECREF(res);
+    if (n < 0) {
+        if (!PyErr_Occurred())
+            PyErr_Format(PyExc_IOError,
+                         "Raw stream returned invalid position %zd", n);
+        return -1;
+    }
+    self->abs_pos = n;
+    return n;
+}
+
+static int
+_Buffered_init(BufferedObject *self)
+{
+    Py_ssize_t n;
+    if (self->buffer_size <= 0) {
+        PyErr_SetString(PyExc_ValueError,
+            "buffer size must be strictly positive");
+        return -1;
+    }
+    if (self->buffer)
+        PyMem_Free(self->buffer);
+    self->buffer = PyMem_Malloc(self->buffer_size);
+    if (self->buffer == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+    self->lock = PyThread_allocate_lock();
+    if (self->lock == NULL) {
+        PyErr_SetString(PyExc_RuntimeError, "can't allocate read lock");
+        return -1;
+    }
+    /* Find out whether buffer_size is a power of 2 */
+    /* XXX is this optimization useful? */
+    for (n = self->buffer_size - 1; n & 1; n >>= 1)
+        ;
+    if (n == 0)
+        self->buffer_mask = self->buffer_size - 1;
+    else
+        self->buffer_mask = 0;
+    if (_Buffered_raw_tell(self) == -1)
+        PyErr_Clear();
+    return 0;
+}
+
+/*
+ * Shared methods and wrappers
+ */
+
+static PyObject *
+Buffered_flush(BufferedObject *self, PyObject *args)
+{
+    PyObject *res;
+
+    CHECK_INITIALIZED(self)
+    if (BufferedIOMixin_closed(self)) {
+        PyErr_SetString(PyExc_ValueError, "flush of closed file");
+        return NULL;
+    }
+
+    ENTER_BUFFERED(self)
+    res = _BufferedWriter_flush_unlocked(self, 0);
+    if (res != NULL && self->readable) {
+        /* Rewind the raw stream so that its position corresponds to
+           the current logical position. */
+        Py_off_t n;
+        n = _Buffered_raw_seek(self, -RAW_OFFSET(self), 1);
+        if (n == -1)
+            Py_CLEAR(res);
+        _BufferedReader_reset_buf(self);
+    }
+    LEAVE_BUFFERED(self)
+
+    return res;
+}
+
+static PyObject *
+Buffered_peek(BufferedObject *self, PyObject *args)
+{
+    Py_ssize_t n = 0;
+    PyObject *res = NULL;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "|n:peek", &n)) {
+        return NULL;
+    }
+
+    ENTER_BUFFERED(self)
+
+    if (self->writable) {
+        res = _BufferedWriter_flush_unlocked(self, 1);
+        if (res == NULL)
+            goto end;
+        Py_CLEAR(res);
+    }
+    res = _BufferedReader_peek_unlocked(self, n);
+
+end:
+    LEAVE_BUFFERED(self)
+    return res;
+}
+
+static PyObject *
+Buffered_read(BufferedObject *self, PyObject *args)
+{
+    Py_ssize_t n = -1;
+    PyObject *res;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "|n:read", &n)) {
+        return NULL;
+    }
+    if (n < -1) {
+        PyErr_SetString(PyExc_ValueError,
+                        "read length must be positive or -1");
+        return NULL;
+    }
+
+    if (BufferedIOMixin_closed(self)) {
+        PyErr_SetString(PyExc_ValueError, "read of closed file");
+        return NULL;
+    }
+
+    ENTER_BUFFERED(self)
+    res = _BufferedReader_read_unlocked(self, n);
+    LEAVE_BUFFERED(self)
+
+    return res;
+}
+
+static PyObject *
+Buffered_read1(BufferedObject *self, PyObject *args)
+{
+    Py_ssize_t n, have, r;
+    PyObject *res = NULL;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "n:read1", &n)) {
+        return NULL;
+    }
+
+    if (n < 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "read length must be positive");
+        return NULL;
+    }
+    if (n == 0)
+        return PyBytes_FromStringAndSize(NULL, 0);
+
+    ENTER_BUFFERED(self)
+    
+    if (self->writable) {
+        res = _BufferedWriter_flush_unlocked(self, 1);
+        if (res == NULL)
+            goto end;
+        Py_CLEAR(res);
+    }
+
+    /* Return up to n bytes.  If at least one byte is buffered, we
+       only return buffered bytes.  Otherwise, we do one raw read. */
+
+    /* XXX: this mimicks the io.py implementation but is probably wrong.
+       If we need to read from the raw stream, then we could actually read
+       all `n` bytes asked by the caller (and possibly more, so as to fill
+       our buffer for the next reads). */
+
+    have = READAHEAD(self);
+    if (have > 0) {
+        if (n > have)
+            n = have;
+        res = PyBytes_FromStringAndSize(self->buffer + self->pos, n);
+        if (res == NULL)
+            goto end;
+        self->pos += n;
+        goto end;
+    }
+
+    /* Fill the buffer from the raw stream, and copy it to the result. */
+    _BufferedReader_reset_buf(self);
+    r = _BufferedReader_fill_buffer(self);
+    if (r == -1)
+        goto end;
+    if (r == -2)
+        r = 0;
+    if (n > r)
+        n = r;
+    res = PyBytes_FromStringAndSize(self->buffer, n);
+    if (res == NULL)
+        goto end;
+    self->pos = n;
+
+end:
+    LEAVE_BUFFERED(self)
+    return res;
+}
+
+static PyObject *
+Buffered_readinto(BufferedObject *self, PyObject *args)
+{
+    PyObject *res = NULL;
+
+    CHECK_INITIALIZED(self)
+    
+    /* TODO: use raw.readinto() instead! */
+    if (self->writable) {
+        ENTER_BUFFERED(self)
+        res = _BufferedWriter_flush_unlocked(self, 0);
+        LEAVE_BUFFERED(self)
+        if (res == NULL)
+            goto end;
+        Py_DECREF(res);
+    }
+    res = BufferedIOBase_readinto((PyObject *)self, args);
+
+end:
+    return res;
+}
+
+static PyObject *
+Buffered_tell(BufferedObject *self, PyObject *args)
+{
+    Py_off_t pos;
+
+    CHECK_INITIALIZED(self)
+    pos = _Buffered_raw_tell(self);
+    if (pos == -1)
+        return NULL;
+    pos -= RAW_OFFSET(self);
+    /* TODO: sanity check (pos >= 0) */
+    return PyLong_FromOff_t(pos);
+}
+
+static PyObject *
+Buffered_seek(BufferedObject *self, PyObject *args)
+{
+    Py_off_t target, n;
+    int whence = 0;
+    PyObject *targetobj, *res = NULL;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "O|i:seek", &targetobj, &whence)) {
+        return NULL;
+    }
+    
+    if (whence < 0 || whence > 2) {
+        PyErr_Format(PyExc_ValueError,
+                     "whence must be between 0 and 2, not %d", whence);
+        return NULL;
+    }
+    target = PyNumber_AsOff_t(targetobj, PyExc_ValueError);
+    if (target == -1 && PyErr_Occurred())
+        return NULL;
+
+    ENTER_BUFFERED(self)
+
+    if (whence != 2 && self->readable) {
+        Py_off_t current, avail;
+        /* Check if seeking leaves us inside the current buffer,
+           so as to return quickly if possible.
+           Don't know how to do that when whence == 2, though. */
+        current = RAW_TELL(self);
+        avail = READAHEAD(self);
+        if (avail > 0) {
+            Py_off_t offset;
+            if (whence == 0)
+                offset = target - (current - RAW_OFFSET(self));
+            else
+                offset = target;
+            if (offset >= -self->pos && offset <= avail) {
+                self->pos += offset;
+                res = PyLong_FromOff_t(current - avail + offset);
+                goto end;
+            }
+        }
+    }
+
+    /* Fallback: invoke raw seek() method and clear buffer */
+    if (self->writable) {
+        res = _BufferedWriter_flush_unlocked(self, 0);
+        if (res == NULL)
+            goto end;
+        Py_CLEAR(res);
+        _BufferedWriter_reset_buf(self);
+    }
+
+    /* TODO: align on block boundary and read buffer if needed? */
+    if (whence == 1)
+        target -= RAW_OFFSET(self);
+    n = _Buffered_raw_seek(self, target, whence);
+    if (n == -1)
+        goto end;
+    self->raw_pos = -1;
+    res = PyLong_FromOff_t(n);
+    if (res != NULL && self->readable)
+        _BufferedReader_reset_buf(self);
+
+end:
+    LEAVE_BUFFERED(self)
+    return res;
+}
+
+static PyObject *
+Buffered_truncate(BufferedObject *self, PyObject *args)
+{
+    PyObject *pos = Py_None;
+    PyObject *res = NULL;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "|O:truncate", &pos)) {
+        return NULL;
+    }
+
+    if (pos != Py_None)
+        Py_INCREF(pos);
+
+    ENTER_BUFFERED(self)
+
+    if (self->writable) {
+        res = _BufferedWriter_flush_unlocked(self, 0);
+        if (res == NULL)
+            goto end;
+        Py_CLEAR(res);
+    }
+    if (self->readable) {
+        if (pos == Py_None) {
+            /* Rewind the raw stream so that its position corresponds to
+               the current logical position. */
+            if (_Buffered_raw_seek(self, -RAW_OFFSET(self), 1) == -1)
+                goto end;
+        }
+        _BufferedReader_reset_buf(self);
+    }
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_truncate, pos, NULL);
+    if (res == NULL)
+        goto end;
+    /* Reset cached position */
+    if (_Buffered_raw_tell(self) == -1)
+        PyErr_Clear();
+
+end:
+    LEAVE_BUFFERED(self)
+    return res;
+}
+
+
+/*
+ * class BufferedReader
+ */
+
+PyDoc_STRVAR(BufferedReader_doc,
+             "Create a new buffered reader using the given readable raw IO object.");
+
+static void _BufferedReader_reset_buf(BufferedObject *self)
+{
+    self->read_end = -1;
+}
+
+static int
+BufferedReader_init(BufferedObject *self, PyObject *args, PyObject *kwds)
+{
+    char *kwlist[] = {"raw", "buffer_size", NULL};
+    Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
+    PyObject *raw;
+
+    self->ok = 0;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedReader", kwlist,
+                                     &raw, &buffer_size)) {
+        return -1;
+    }
+
+    if (_PyIOBase_checkReadable(raw, Py_True) == NULL)
+        return -1;
+
+    Py_CLEAR(self->raw);
+    Py_INCREF(raw);
+    self->raw = raw;
+    self->buffer_size = buffer_size;
+    self->readable = 1;
+    self->writable = 0;
+
+    if (_Buffered_init(self) < 0)
+        return -1;
+    _BufferedReader_reset_buf(self);
+
+    self->ok = 1;
+    return 0;
+}
+
+static Py_ssize_t
+_BufferedReader_raw_read(BufferedObject *self, char *start, Py_ssize_t len)
+{
+    Py_buffer buf;
+    PyObject *memobj, *res;
+    Py_ssize_t n;
+    /* NOTE: the buffer needn't be released as its object is NULL. */
+    if (PyBuffer_FillInfo(&buf, NULL, start, len, 0, PyBUF_CONTIG) == -1)
+        return -1;
+    memobj = PyMemoryView_FromBuffer(&buf);
+    if (memobj == NULL)
+        return -1;
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_readinto, memobj, NULL);
+    Py_DECREF(memobj);
+    if (res == NULL)
+        return -1;
+    if (res == Py_None) {
+        /* Non-blocking stream would have blocked. Special return code! */
+        Py_DECREF(res);
+        return -2;
+    }
+    n = PyNumber_AsSsize_t(res, PyExc_ValueError);
+    Py_DECREF(res);
+    if (n < 0 || n > len) {
+        PyErr_Format(PyExc_IOError,
+                     "raw readinto() returned invalid length %zd "
+                     "(should have been between 0 and %zd)", n, len);
+        return -1;
+    }
+    if (n > 0 && self->abs_pos != -1)
+        self->abs_pos += n;
+    return n;
+}
+
+static Py_ssize_t
+_BufferedReader_fill_buffer(BufferedObject *self)
+{
+    Py_ssize_t start, len, n;
+    if (VALID_READ_BUFFER(self))
+        start = self->read_end;
+    else
+        start = 0;
+    len = self->buffer_size - start;
+    n = _BufferedReader_raw_read(self, self->buffer + start, len);
+    if (n <= 0)
+        return n;
+    self->read_end = start + n;
+    self->raw_pos = start + n;
+    return n;
+}
+
+static PyObject *
+_BufferedReader_read_unlocked(BufferedObject *self, Py_ssize_t n)
+{
+    PyObject *data, *res = NULL;
+    Py_ssize_t current_size, remaining, written;
+    char *out;
+    static PyObject *sep = NULL;
+
+    /* Special case for when the number of bytes to read is unspecified. */
+    if (n == -1) {
+        PyObject *chunks = PyList_New(0);
+        if (chunks == NULL)
+            return NULL;
+
+        /* First copy what we have in the current buffer. */
+        current_size = READAHEAD(self);
+        data = NULL;
+        if (current_size) {
+            data = PyBytes_FromStringAndSize(
+                self->buffer + self->pos, current_size);
+            if (data == NULL) {
+                Py_DECREF(chunks);
+                return NULL;
+            }
+        }
+        _BufferedReader_reset_buf(self);
+        /* We're going past the buffer's bounds, flush it */
+        if (self->writable) {
+            res = _BufferedWriter_flush_unlocked(self, 1);
+            if (res == NULL) {
+                Py_DECREF(chunks);
+                return NULL;
+            }
+            Py_CLEAR(res);
+        }
+        while (1) {
+            if (data) {
+                if (PyList_Append(chunks, data) < 0) {
+                    Py_DECREF(data);
+                    Py_DECREF(chunks);
+                    return NULL;
+                }
+                Py_DECREF(data);
+            }
+
+            /* Read until EOF or until read() would block. */
+            data = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_read, NULL);
+            if (data == NULL) {
+                Py_DECREF(chunks);
+                return NULL;
+            }
+            if (data != Py_None && !PyBytes_Check(data)) {
+                Py_DECREF(data);
+                Py_DECREF(chunks);
+                PyErr_SetString(PyExc_TypeError, "read() should return bytes");
+                return NULL;
+            }
+            if (data == Py_None || PyBytes_GET_SIZE(data) == 0) {
+                if (current_size == 0) {
+                    Py_DECREF(chunks);
+                    return data;
+                }
+                else {
+                    if (sep == NULL) {
+                        sep = PyBytes_FromStringAndSize(NULL, 0);
+                        if (sep == NULL) {
+                            Py_DECREF(data);
+                            Py_DECREF(chunks);
+                            return NULL;
+                        }
+                    }
+                    res =_PyBytes_Join(sep, chunks);
+                    Py_DECREF(data);
+                    Py_DECREF(chunks);
+                    return res;
+                }
+            }
+            current_size += PyBytes_GET_SIZE(data);
+            if (self->abs_pos != -1)
+                self->abs_pos += PyBytes_GET_SIZE(data);
+        }
+    }
+
+    /* The number of bytes to read is specified, return at most n bytes. */
+    current_size = READAHEAD(self);
+    if (n <= current_size) {
+        /* Fast path: the data to read is fully buffered. */
+        res = PyBytes_FromStringAndSize(self->buffer + self->pos, n);
+        if (res == NULL)
+            goto error;
+        self->pos += n;
+        return res;
+    }
+
+    /* Slow path: read from the stream until enough bytes are read,
+     * or until an EOF occurs or until read() would block.
+     */
+    res = PyBytes_FromStringAndSize(NULL, n);
+    if (res == NULL)
+        goto error;
+    out = PyBytes_AS_STRING(res);
+    remaining = n;
+    written = 0;
+    if (current_size > 0) {
+        memcpy(out, self->buffer + self->pos, current_size);
+        remaining -= current_size;
+        written += current_size;
+    }
+    _BufferedReader_reset_buf(self);
+    while (remaining > 0) {
+        /* We want to read a whole block at the end into buffer.
+           If we had readv() we could do this in one pass. */
+        Py_ssize_t r = MINUS_LAST_BLOCK(self, remaining);
+        if (r == 0)
+            break;
+        r = _BufferedReader_raw_read(self, out + written, r);
+        if (r == -1)
+            goto error;
+        if (r == 0 || r == -2) {
+            /* EOF occurred or read() would block. */
+            if (r == 0 || written > 0) {
+                if (_PyBytes_Resize(&res, written))
+                    goto error;
+                return res;
+            }
+            Py_DECREF(res);
+            Py_INCREF(Py_None);
+            return Py_None;
+        }
+        remaining -= r;
+        written += r;
+    }
+    assert(remaining <= self->buffer_size);
+    self->pos = 0;
+    self->raw_pos = 0;
+    self->read_end = 0;
+    while (self->read_end < self->buffer_size) {
+        Py_ssize_t r = _BufferedReader_fill_buffer(self);
+        if (r == -1)
+            goto error;
+        if (r == 0 || r == -2) {
+            /* EOF occurred or read() would block. */
+            if (r == 0 || written > 0) {
+                if (_PyBytes_Resize(&res, written))
+                    goto error;
+                return res;
+            }
+            Py_DECREF(res);
+            Py_INCREF(Py_None);
+            return Py_None;
+        }
+        if (remaining > r) {
+            memcpy(out + written, self->buffer + self->pos, r);
+            written += r;
+            self->pos += r;
+            remaining -= r;
+        }
+        else if (remaining > 0) {
+            memcpy(out + written, self->buffer + self->pos, remaining);
+            written += remaining;
+            self->pos += remaining;
+            remaining = 0;
+        }
+        if (remaining == 0)
+            break;
+    }
+
+    return res;
+
+error:
+    Py_XDECREF(res);
+    return NULL;
+}
+
+static PyObject *
+_BufferedReader_peek_unlocked(BufferedObject *self, Py_ssize_t n)
+{
+    Py_ssize_t have, r;
+
+    have = READAHEAD(self);
+    /* Constraints:
+       1. we don't want to advance the file position.
+       2. we don't want to lose block alignment, so we can't shift the buffer
+          to make some place.
+       Therefore, we either return `have` bytes (if > 0), or a full buffer.
+    */
+    if (have > 0) {
+        return PyBytes_FromStringAndSize(self->buffer + self->pos, have);
+    }
+
+    /* Fill the buffer from the raw stream, and copy it to the result. */
+    _BufferedReader_reset_buf(self);
+    r = _BufferedReader_fill_buffer(self);
+    if (r == -1)
+        return NULL;
+    if (r == -2)
+        r = 0;
+    self->pos = 0;
+    return PyBytes_FromStringAndSize(self->buffer, r);
+}
+
+static PyMethodDef BufferedReader_methods[] = {
+    /* BufferedIOMixin methods */
+    {"truncate", (PyCFunction)BufferedIOMixin_truncate, METH_VARARGS},
+    {"flush", (PyCFunction)BufferedIOMixin_flush, METH_NOARGS},
+    {"close", (PyCFunction)BufferedIOMixin_close, METH_NOARGS},
+    {"seekable", (PyCFunction)BufferedIOMixin_seekable, METH_NOARGS},
+    {"readable", (PyCFunction)BufferedIOMixin_readable, METH_NOARGS},
+    {"writable", (PyCFunction)BufferedIOMixin_writable, METH_NOARGS},
+    {"fileno", (PyCFunction)BufferedIOMixin_fileno, METH_NOARGS},
+    {"isatty", (PyCFunction)BufferedIOMixin_isatty, METH_NOARGS},
+
+    {"read", (PyCFunction)Buffered_read, METH_VARARGS},
+    {"peek", (PyCFunction)Buffered_peek, METH_VARARGS},
+    {"read1", (PyCFunction)Buffered_read1, METH_VARARGS},
+    {"seek", (PyCFunction)Buffered_seek, METH_VARARGS},
+    {"tell", (PyCFunction)Buffered_tell, METH_NOARGS},
+    {NULL, NULL}
+};
+
+static PyMemberDef BufferedReader_members[] = {
+    {"raw", T_OBJECT, offsetof(BufferedObject, raw), 0},
+    {NULL}
+};
+
+static PyGetSetDef BufferedReader_getset[] = {
+    {"closed", (getter)BufferedIOMixin_closed_get, NULL, NULL},
+    {"name", (getter)BufferedIOMixin_name_get, NULL, NULL},
+    {"mode", (getter)BufferedIOMixin_mode_get, NULL, NULL},
+    {0}
+};
+
+
+PyTypeObject PyBufferedReader_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "BufferedReader",           /*tp_name*/
+    sizeof(BufferedObject),     /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    (destructor)BufferedObject_dealloc,     /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    BufferedReader_doc,         /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+        offsetof(BufferedObject, weakreflist), /*tp_weaklistoffset*/
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    BufferedReader_methods,     /* tp_methods */
+    BufferedReader_members,     /* tp_members */
+    BufferedReader_getset,      /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    offsetof(BufferedObject, dict), /* tp_dictoffset */
+    (initproc)BufferedReader_init, /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+};
+
+
+/*
+ * class BufferedWriter
+ */
+PyDoc_STRVAR(BufferedWriter_doc,
+    "A buffer for a writeable sequential RawIO object.\n"
+    "\n"
+    "The constructor creates a BufferedWriter for the given writeable raw\n"
+    "stream. If the buffer_size is not given, it defaults to\n"
+    "DEFAULT_BUFFER_SIZE. max_buffer_size isn't used anymore.\n"
+    );
+
+static void
+_BufferedWriter_reset_buf(BufferedObject *self)
+{
+    self->write_pos = 0;
+    self->write_end = -1;
+}
+
+static int
+BufferedWriter_init(BufferedObject *self, PyObject *args, PyObject *kwds)
+{
+    /* TODO: properly deprecate max_buffer_size */
+    char *kwlist[] = {"raw", "buffer_size", "max_buffer_size", NULL};
+    Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
+    Py_ssize_t max_buffer_size = -1;
+    PyObject *raw;
+
+    self->ok = 0;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|nn:BufferedReader", kwlist,
+                                     &raw, &buffer_size, &max_buffer_size)) {
+        return -1;
+    }
+
+    if (_PyIOBase_checkWritable(raw, Py_True) == NULL)
+        return -1;
+
+    Py_CLEAR(self->raw);
+    Py_INCREF(raw);
+    self->raw = raw;
+    self->readable = 0;
+    self->writable = 1;
+
+    self->buffer_size = buffer_size;
+    if (_Buffered_init(self) < 0)
+        return -1;
+    _BufferedWriter_reset_buf(self);
+    self->pos = 0;
+
+    self->ok = 1;
+    return 0;
+}
+
+static Py_ssize_t
+_BufferedWriter_raw_write(BufferedObject *self, char *start, Py_ssize_t len)
+{
+    Py_buffer buf;
+    PyObject *memobj, *res;
+    Py_ssize_t n;
+    /* NOTE: the buffer needn't be released as its object is NULL. */
+    if (PyBuffer_FillInfo(&buf, NULL, start, len, 1, PyBUF_CONTIG_RO) == -1)
+        return -1;
+    memobj = PyMemoryView_FromBuffer(&buf);
+    if (memobj == NULL)
+        return -1;
+    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_write, memobj, NULL);
+    Py_DECREF(memobj);
+    if (res == NULL)
+        return -1;
+    n = PyNumber_AsSsize_t(res, PyExc_ValueError);
+    Py_DECREF(res);
+    if (n < 0 || n > len) {
+        PyErr_Format(PyExc_IOError,
+                     "raw write() returned invalid length %zd "
+                     "(should have been between 0 and %zd)", n, len);
+        return -1;
+    }
+    if (n > 0 && self->abs_pos != -1)
+        self->abs_pos += n;
+    return n;
+}
+
+/* `restore_pos` is 1 if we need to restore the raw stream position at
+   the end, 0 otherwise. */
+static PyObject *
+_BufferedWriter_flush_unlocked(BufferedObject *self, int restore_pos)
+{
+    Py_ssize_t written = 0;
+    Py_off_t n, rewind;
+
+    if (!VALID_WRITE_BUFFER(self) || self->write_pos == self->write_end)
+        goto end;
+    /* First, rewind */
+    rewind = RAW_OFFSET(self) + (self->pos - self->write_pos);
+    if (rewind != 0) {
+        n = _Buffered_raw_seek(self, -rewind, 1);
+        if (n < 0) {
+            goto error;
+        }
+        self->raw_pos -= rewind;
+    }
+    while (self->write_pos < self->write_end) {
+        n = _BufferedWriter_raw_write(self,
+            self->buffer + self->write_pos,
+            self->write_end - self->write_pos);
+        if (n == -1) {
+            Py_ssize_t *w = _Buffered_check_blocking_error();
+            if (w == NULL)
+                goto error;
+            self->write_pos += *w;
+            self->raw_pos = self->write_pos;
+            written += *w;
+            *w = written;
+            /* Already re-raised */
+            goto error;
+        }
+        self->write_pos += n;
+        self->raw_pos = self->write_pos;
+        written += n;
+    }
+
+    if (restore_pos) {
+        Py_off_t forward = rewind - written;
+        if (forward != 0) {
+            n = _Buffered_raw_seek(self, forward, 1);
+            if (n < 0) {
+                goto error;
+            }
+            self->raw_pos += forward;
+        }
+    }
+    _BufferedWriter_reset_buf(self);
+
+end:
+    Py_RETURN_NONE;
+
+error:
+    return NULL;
+}
+
+static PyObject *
+BufferedWriter_write(BufferedObject *self, PyObject *args)
+{
+    PyObject *res = NULL;
+    Py_buffer buf;
+    Py_ssize_t written, avail, remaining, n;
+
+    CHECK_INITIALIZED(self)
+    if (!PyArg_ParseTuple(args, "y*:write", &buf)) {
+        return NULL;
+    }
+
+    if (BufferedIOMixin_closed(self)) {
+        PyErr_SetString(PyExc_ValueError, "write to closed file");
+        PyBuffer_Release(&buf);
+        return NULL;
+    }
+
+    ENTER_BUFFERED(self)
+
+    /* Fast path: the data to write can be fully buffered. */
+    if (!VALID_READ_BUFFER(self) && !VALID_WRITE_BUFFER(self)) {
+        self->pos = 0;
+        self->raw_pos = 0;
+    }
+    avail = self->buffer_size - self->pos;
+    if (buf.len <= avail) {
+        memcpy(self->buffer + self->pos, buf.buf, buf.len);
+        if (!VALID_WRITE_BUFFER(self)) {
+            self->write_pos = self->pos;
+        }
+        ADJUST_POSITION(self, self->pos + buf.len);
+        if (self->pos > self->write_end)
+            self->write_end = self->pos;
+        written = buf.len;
+        goto end;
+    }
+
+    /* First write the current buffer */
+    res = _BufferedWriter_flush_unlocked(self, 0);
+    if (res == NULL) {
+        Py_ssize_t *w = _Buffered_check_blocking_error();
+        if (w == NULL)
+            goto error;
+        if (self->readable)
+            _BufferedReader_reset_buf(self);
+        /* Make some place by shifting the buffer. */
+        assert(VALID_WRITE_BUFFER(self));
+        memmove(self->buffer, self->buffer + self->write_pos,
+                self->write_end - self->write_pos);
+        self->write_end -= self->write_pos;
+        self->raw_pos -= self->write_pos;
+        self->pos -= self->write_pos;
+        self->write_pos = 0;
+        avail = self->buffer_size - self->write_end;
+        if (buf.len <= avail) {
+            /* Everything can be buffered */
+            PyErr_Clear();
+            memcpy(self->buffer + self->write_end, buf.buf, buf.len);
+            self->write_end += buf.len;
+            written = buf.len;
+            goto end;
+        }
+        /* Buffer as much as possible. */
+        memcpy(self->buffer + self->write_end, buf.buf, avail);
+        self->write_end += avail;
+        /* Already re-raised */
+        *w = avail;
+        goto error;
+    }
+    Py_CLEAR(res);
+
+    /* Then write buf itself. At this point the buffer has been emptied. */
+    remaining = buf.len;
+    written = 0;
+    while (remaining > self->buffer_size) {
+        n = _BufferedWriter_raw_write(
+            self, (char *) buf.buf + written, buf.len - written);
+        if (n == -1) {
+            Py_ssize_t *w = _Buffered_check_blocking_error();
+            if (w == NULL)
+                goto error;
+            written += *w;
+            remaining -= *w;
+            if (remaining > self->buffer_size) {
+                /* Can't buffer everything, still buffer as much as possible */
+                memcpy(self->buffer,
+                       (char *) buf.buf + written, self->buffer_size);
+                self->raw_pos = 0;
+                ADJUST_POSITION(self, self->buffer_size);
+                self->write_end = self->buffer_size;
+                *w = written + self->buffer_size;
+                /* Already re-raised */
+                goto error;
+            }
+            PyErr_Clear();
+            break;
+        }
+        written += n;
+        remaining -= n;
+    }
+    if (self->readable)
+        _BufferedReader_reset_buf(self);
+    if (remaining > 0) {
+        memcpy(self->buffer, (char *) buf.buf + written, remaining);
+        written += remaining;
+    }
+    self->write_pos = 0;
+    /* TODO: sanity check (remaining >= 0) */
+    self->write_end = remaining;
+    ADJUST_POSITION(self, remaining);
+    self->raw_pos = 0;
+
+end:
+    res = PyLong_FromSsize_t(written);
+
+error:
+    LEAVE_BUFFERED(self)
+    PyBuffer_Release(&buf);
+    return res;
+}
+
+static PyMethodDef BufferedWriter_methods[] = {
+    /* BufferedIOMixin methods */
+    {"close", (PyCFunction)BufferedIOMixin_close, METH_NOARGS},
+    {"seekable", (PyCFunction)BufferedIOMixin_seekable, METH_NOARGS},
+    {"readable", (PyCFunction)BufferedIOMixin_readable, METH_NOARGS},
+    {"writable", (PyCFunction)BufferedIOMixin_writable, METH_NOARGS},
+    {"fileno", (PyCFunction)BufferedIOMixin_fileno, METH_NOARGS},
+    {"isatty", (PyCFunction)BufferedIOMixin_isatty, METH_NOARGS},
+
+    {"write", (PyCFunction)BufferedWriter_write, METH_VARARGS},
+    {"truncate", (PyCFunction)Buffered_truncate, METH_VARARGS},
+    {"flush", (PyCFunction)Buffered_flush, METH_NOARGS},
+    {"seek", (PyCFunction)Buffered_seek, METH_VARARGS},
+    {"tell", (PyCFunction)Buffered_tell, METH_NOARGS},
+    {NULL, NULL}
+};
+
+static PyMemberDef BufferedWriter_members[] = {
+    {"raw", T_OBJECT, offsetof(BufferedObject, raw), 0},
+    {NULL}
+};
+
+static PyGetSetDef BufferedWriter_getset[] = {
+    {"closed", (getter)BufferedIOMixin_closed_get, NULL, NULL},
+    {"name", (getter)BufferedIOMixin_name_get, NULL, NULL},
+    {"mode", (getter)BufferedIOMixin_mode_get, NULL, NULL},
+    {0}
+};
+
+
+PyTypeObject PyBufferedWriter_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "BufferedWriter",           /*tp_name*/
+    sizeof(BufferedObject),     /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    (destructor)BufferedObject_dealloc,     /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    BufferedWriter_doc,         /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    offsetof(BufferedObject, weakreflist), /*tp_weaklistoffset*/
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    BufferedWriter_methods,     /* tp_methods */
+    BufferedWriter_members,     /* tp_members */
+    BufferedWriter_getset,      /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    offsetof(BufferedObject, dict), /* tp_dictoffset */
+    (initproc)BufferedWriter_init, /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+};
+
+
+
+/*
+ * BufferedRWPair
+ */
+
+PyDoc_STRVAR(BufferedRWPair_doc,
+    "A buffered reader and writer object together.\n"
+    "\n"
+    "A buffered reader object and buffered writer object put together to\n"
+    "form a sequential IO object that can read and write. This is typically\n"
+    "used with a socket or two-way pipe.\n"
+    "\n"
+    "reader and writer are RawIOBase objects that are readable and\n"
+    "writeable respectively. If the buffer_size is omitted it defaults to\n"
+    "DEFAULT_BUFFER_SIZE. The max_buffer_size (for the buffered writer)\n"
+    "defaults to twice the buffer size.\n"
+    );
+
+/* XXX The usefulness of this (compared to having two separate IO objects) is
+ * questionable.
+ */
+
+typedef struct {
+    PyObject_HEAD
+    BufferedObject *reader;
+    BufferedObject *writer;
+    PyObject *dict;
+} BufferedRWPairObject;
+
+static int
+BufferedRWPair_init(BufferedRWPairObject *self, PyObject *args,
+                     PyObject *kwds)
+{
+    PyObject *reader, *writer;
+    Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
+    Py_ssize_t max_buffer_size = -1;
+
+    if (!PyArg_ParseTuple(args, "OO|nn:BufferedRWPair", &reader, &writer,
+                          &buffer_size, &max_buffer_size)) {
+        return -1;
+    }
+
+    if (_PyIOBase_checkReadable(reader, Py_True) == NULL)
+        return -1;
+    if (_PyIOBase_checkWritable(writer, Py_True) == NULL)
+        return -1;
+
+    args = Py_BuildValue("(n)", buffer_size);
+    if (args == NULL) {
+        Py_CLEAR(self->reader);
+        return -1;
+    }
+    self->reader = (BufferedObject *)PyType_GenericNew(
+            &PyBufferedReader_Type, args, NULL);
+    Py_DECREF(args);
+    if (self->reader == NULL)
+        return -1;
+
+    args = Py_BuildValue("(nn)", buffer_size, max_buffer_size);
+    if (args == NULL) {
+        Py_CLEAR(self->reader);
+        return -1;
+    }
+    self->writer = (BufferedObject *)PyType_GenericNew(
+            &PyBufferedWriter_Type, args, NULL);
+    Py_DECREF(args);
+    if (self->writer == NULL) {
+        Py_CLEAR(self->reader);
+        return -1;
+    }
+    return 0;
+}
+
+static void
+BufferedRWPair_dealloc(BufferedRWPairObject *self)
+{
+    Py_CLEAR(self->reader);
+    Py_CLEAR(self->writer);
+}
+
+static PyObject *
+_forward_call(BufferedObject *self, const char *name, PyObject *args)
+{
+    PyObject *func = PyObject_GetAttrString((PyObject *)self, name);
+    PyObject *ret;
+
+    if (func == NULL) {
+        PyErr_SetString(PyExc_AttributeError, name);
+        return NULL;
+    }
+
+    ret = PyObject_CallObject(func, args);
+    Py_DECREF(func);
+    return ret;
+}
+
+static PyObject *
+BufferedRWPair_read(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->reader, "read", args);
+}
+
+static PyObject *
+BufferedRWPair_peek(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->reader, "peek", args);
+}
+
+static PyObject *
+BufferedRWPair_read1(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->reader, "read1", args);
+}
+
+static PyObject *
+BufferedRWPair_write(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->writer, "write", args);
+}
+
+static PyObject *
+BufferedRWPair_flush(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->writer, "flush", args);
+}
+
+static PyObject *
+BufferedRWPair_readable(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->reader, "readable", args);
+}
+
+static PyObject *
+BufferedRWPair_writable(BufferedRWPairObject *self, PyObject *args)
+{
+    return _forward_call(self->writer, "writable", args);
+}
+
+static PyObject *
+BufferedRWPair_close(BufferedRWPairObject *self, PyObject *args)
+{
+    PyObject *ret = _forward_call(self->writer, "close", args);
+    if (ret == NULL)
+        return NULL;
+    Py_DECREF(ret);
+
+    return _forward_call(self->reader, "close", args);
+}
+
+static PyObject *
+BufferedRWPair_isatty(BufferedRWPairObject *self, PyObject *args)
+{
+    PyObject *ret = _forward_call(self->writer, "isatty", args);
+
+    if (ret != Py_False) {
+        /* either True or exception */
+        return ret;
+    }
+    Py_DECREF(ret);
+
+    return _forward_call(self->reader, "isatty", args);
+}
+
+
+static PyMethodDef BufferedRWPair_methods[] = {
+    {"read", (PyCFunction)BufferedRWPair_read, METH_VARARGS},
+    {"peek", (PyCFunction)BufferedRWPair_peek, METH_VARARGS},
+    {"read1", (PyCFunction)BufferedRWPair_read1, METH_VARARGS},
+    {"readinto", (PyCFunction)Buffered_readinto, METH_VARARGS},
+
+    {"write", (PyCFunction)BufferedRWPair_write, METH_VARARGS},
+    {"flush", (PyCFunction)BufferedRWPair_flush, METH_NOARGS},
+
+    {"readable", (PyCFunction)BufferedRWPair_readable, METH_NOARGS},
+    {"writable", (PyCFunction)BufferedRWPair_writable, METH_NOARGS},
+
+    {"close", (PyCFunction)BufferedRWPair_close, METH_NOARGS},
+    {"isatty", (PyCFunction)BufferedRWPair_isatty, METH_NOARGS},
+
+    {NULL, NULL}
+};
+
+PyTypeObject PyBufferedRWPair_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "BufferedRWPair",           /*tp_name*/
+    sizeof(BufferedRWPairObject),     /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    (destructor)BufferedRWPair_dealloc,     /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    BufferedRWPair_doc,         /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    offsetof(BufferedObject, weakreflist), /*tp_weaklistoffset*/
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    BufferedRWPair_methods,     /* tp_methods */
+    0,     /* tp_members */
+    0,      /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    offsetof(BufferedRWPairObject, dict), /* tp_dictoffset */
+    (initproc)BufferedRWPair_init, /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+};
+
+
+
+/*
+ * BufferedRandom
+ */
+
+PyDoc_STRVAR(BufferedRandom_doc,
+    "A buffered interface to random access streams.\n"
+    "\n"
+    "The constructor creates a reader and writer for a seekable stream,\n"
+    "raw, given in the first argument. If the buffer_size is omitted it\n"
+    "defaults to DEFAULT_BUFFER_SIZE. max_buffer_size isn't used anymore.\n"
+    );
+
+static int
+BufferedRandom_init(BufferedObject *self, PyObject *args, PyObject *kwds)
+{
+    char *kwlist[] = {"raw", "buffer_size", "max_buffer_size", NULL};
+    Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
+    Py_ssize_t max_buffer_size = -1;
+    PyObject *raw;
+
+    self->ok = 0;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|nn:BufferedReader", kwlist,
+                                     &raw, &buffer_size, &max_buffer_size)) {
+        return -1;
+    }
+
+    if (_PyIOBase_checkSeekable(raw, Py_True) == NULL)
+        return -1;
+    if (_PyIOBase_checkReadable(raw, Py_True) == NULL)
+        return -1;
+    if (_PyIOBase_checkWritable(raw, Py_True) == NULL)
+        return -1;
+
+    Py_CLEAR(self->raw);
+    Py_INCREF(raw);
+    self->raw = raw;
+    self->buffer_size = buffer_size;
+    self->readable = 1;
+    self->writable = 1;
+
+    if (_Buffered_init(self) < 0)
+        return -1;
+    _BufferedReader_reset_buf(self);
+    _BufferedWriter_reset_buf(self);
+    self->pos = 0;
+
+    self->ok = 1;
+    return 0;
+}
+
+static PyMethodDef BufferedRandom_methods[] = {
+    /* BufferedIOMixin methods */
+    {"close", (PyCFunction)BufferedIOMixin_close, METH_NOARGS},
+    {"seekable", (PyCFunction)BufferedIOMixin_seekable, METH_NOARGS},
+    {"readable", (PyCFunction)BufferedIOMixin_readable, METH_NOARGS},
+    {"writable", (PyCFunction)BufferedIOMixin_writable, METH_NOARGS},
+    {"fileno", (PyCFunction)BufferedIOMixin_fileno, METH_NOARGS},
+    {"isatty", (PyCFunction)BufferedIOMixin_isatty, METH_NOARGS},
+
+    {"flush", (PyCFunction)Buffered_flush, METH_NOARGS},
+
+    {"seek", (PyCFunction)Buffered_seek, METH_VARARGS},
+    {"tell", (PyCFunction)Buffered_tell, METH_NOARGS},
+    {"truncate", (PyCFunction)Buffered_truncate, METH_VARARGS},
+    {"read", (PyCFunction)Buffered_read, METH_VARARGS},
+    {"read1", (PyCFunction)Buffered_read1, METH_VARARGS},
+    {"readinto", (PyCFunction)Buffered_readinto, METH_VARARGS},
+    {"peek", (PyCFunction)Buffered_peek, METH_VARARGS},
+    {"write", (PyCFunction)BufferedWriter_write, METH_VARARGS},
+    {NULL, NULL}
+};
+
+static PyMemberDef BufferedRandom_members[] = {
+    {"raw", T_OBJECT, offsetof(BufferedObject, raw), 0},
+    {NULL}
+};
+
+static PyGetSetDef BufferedRandom_getset[] = {
+    {"closed", (getter)BufferedIOMixin_closed_get, NULL, NULL},
+    {"name", (getter)BufferedIOMixin_name_get, NULL, NULL},
+    {"mode", (getter)BufferedIOMixin_mode_get, NULL, NULL},
+    {0}
+};
+
+
+PyTypeObject PyBufferedRandom_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "BufferedRandom",           /*tp_name*/
+    sizeof(BufferedObject),     /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    (destructor)BufferedObject_dealloc,     /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    BufferedRandom_doc,         /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    offsetof(BufferedObject, weakreflist), /*tp_weaklistoffset*/
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    BufferedRandom_methods,     /* tp_methods */
+    BufferedRandom_members,     /* tp_members */
+    BufferedRandom_getset,      /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /*tp_dict*/
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    offsetof(BufferedObject, dict), /*tp_dictoffset*/
+    (initproc)BufferedRandom_init, /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+};
+

Modified: python/branches/io-c/Modules/_bytesio.c
==============================================================================
--- python/branches/io-c/Modules/_bytesio.c	(original)
+++ python/branches/io-c/Modules/_bytesio.c	Sun Jan 18 00:13:48 2009
@@ -1,4 +1,6 @@
 #include "Python.h"
+#include "structmember.h"       /* for offsetof() */
+#include "_iomodule.h"
 
 typedef struct {
     PyObject_HEAD
@@ -6,6 +8,8 @@
     Py_ssize_t pos;
     Py_ssize_t string_size;
     size_t buf_size;
+    PyObject *dict;
+    PyObject *weakreflist;
 } BytesIOObject;
 
 #define CHECK_CLOSED(self)                                  \
@@ -689,7 +693,7 @@
 "Create a buffered I/O implementation using an in-memory bytes\n"
 "buffer, ready for reading and writing.");
 
-static PyTypeObject BytesIO_Type = {
+PyTypeObject PyBytesIO_Type = {
     PyVarObject_HEAD_INIT(NULL, 0)
     "_bytesio._BytesIO",                       /*tp_name*/
     sizeof(BytesIOObject),                     /*tp_basicsize*/
@@ -714,7 +718,7 @@
     0,                                         /*tp_traverse*/
     0,                                         /*tp_clear*/
     0,                                         /*tp_richcompare*/
-    0,                                         /*tp_weaklistoffset*/
+    offsetof(BytesIOObject, weakreflist),      /*tp_weaklistoffset*/
     PyObject_SelfIter,                         /*tp_iter*/
     (iternextfunc)bytesio_iternext,            /*tp_iternext*/
     bytesio_methods,                           /*tp_methods*/
@@ -724,36 +728,8 @@
     0,                                         /*tp_dict*/
     0,                                         /*tp_descr_get*/
     0,                                         /*tp_descr_set*/
-    0,                                         /*tp_dictoffset*/
+    offsetof(BytesIOObject, dict),             /*tp_dictoffset*/
     (initproc)bytesio_init,                    /*tp_init*/
     0,                                         /*tp_alloc*/
     bytesio_new,                               /*tp_new*/
 };
-
-
-static struct PyModuleDef _bytesiomodule = {
-	PyModuleDef_HEAD_INIT,
-	"_bytesio",
-	NULL,
-	-1,
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	NULL
-};
-
-PyMODINIT_FUNC
-PyInit__bytesio(void)
-{
-    PyObject *m;
-
-    if (PyType_Ready(&BytesIO_Type) < 0)
-        return NULL;
-    m = PyModule_Create(&_bytesiomodule);
-    if (m == NULL)
-        return NULL;
-    Py_INCREF(&BytesIO_Type);
-    PyModule_AddObject(m, "_BytesIO", (PyObject *)&BytesIO_Type);
-    return m;
-}

Modified: python/branches/io-c/Modules/_fileio.c
==============================================================================
--- python/branches/io-c/Modules/_fileio.c	(original)
+++ python/branches/io-c/Modules/_fileio.c	Sun Jan 18 00:13:48 2009
@@ -6,6 +6,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <stddef.h> /* For offsetof */
+#include "_iomodule.h"
 
 /*
  * Known likely problems:
@@ -49,6 +50,7 @@
 	int seekable : 2; /* -1 means unknown */
 	int closefd : 1;
 	PyObject *weakreflist;
+	PyObject *dict;
 } PyFileIOObject;
 
 PyTypeObject PyFileIO_Type;
@@ -85,14 +87,18 @@
 		self->fd = -1;
 		Py_RETURN_NONE;
 	}
-	if (internal_close(self))
+	errno = internal_close(self);
+	if (errno < 0) {
+		PyErr_SetFromErrno(PyExc_IOError);
 		return NULL;
+	}
 
-	Py_RETURN_NONE;
+	return PyObject_CallMethod((PyObject*)&PyRawIOBase_Type,
+				   "close", "O", self);
 }
 
 static PyObject *
-fileio_new(PyTypeObject *type, PyObject *args, PyObject *kews)
+fileio_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
 	PyFileIOObject *self;
 
@@ -116,7 +122,7 @@
    directories, so we need a check.  */
 
 static int
-dircheck(PyFileIOObject* self, char *name)
+dircheck(PyFileIOObject* self, const char *name)
 {
 #if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR)
 	struct stat buf;
@@ -144,7 +150,8 @@
 {
 	PyFileIOObject *self = (PyFileIOObject *) oself;
 	static char *kwlist[] = {"file", "mode", "closefd", NULL};
-	char *name = NULL;
+	const char *name = NULL;
+	PyObject *nameobj;
 	char *mode = "r";
 	char *s;
 #ifdef MS_WINDOWS
@@ -163,40 +170,58 @@
 			return -1;
 	}
 
-	if (PyArg_ParseTupleAndKeywords(args, kwds, "i|si:fileio",
-					kwlist, &fd, &mode, &closefd)) {
-		if (fd < 0) {
+	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|si:fileio",
+					 kwlist, &nameobj, &mode, &closefd))
+		return -1;
+
+	if (PyFloat_Check(nameobj)) {
+		PyErr_SetString(PyExc_TypeError,
+				"integer argument expected, got float");
+		return -1;
+	}
+
+	fd = PyLong_AsLong(nameobj);
+	if (fd < 0) {
+		if (!PyErr_Occurred()) {
 			PyErr_SetString(PyExc_ValueError,
 					"Negative filedescriptor");
 			return -1;
 		}
-	}
-	else {
 		PyErr_Clear();
+	}
 
 #ifdef Py_WIN_WIDE_FILENAMES
-	    if (GetVersion() < 0x80000000) {
+	if (GetVersion() < 0x80000000) {
 		/* On NT, so wide API available */
-		PyObject *po;
-		if (PyArg_ParseTupleAndKeywords(args, kwds, "U|si:fileio",
-						kwlist, &po, &mode, &closefd)
-						) {
-			widename = PyUnicode_AS_UNICODE(po);
-		} else {
-			/* Drop the argument parsing error as narrow
-			   strings are also valid. */
-			PyErr_Clear();
-		}
-	    }
-	    if (widename == NULL)
-#endif
-	    {
-		if (!PyArg_ParseTupleAndKeywords(args, kwds, "et|si:fileio",
-						 kwlist,
-						 Py_FileSystemDefaultEncoding,
-						 &name, &mode, &closefd))
-			return -1;
-	    }
+		if (PyUnicode_Check(nameobj))
+			widename = PyUnicode_AS_UNICODE(nameobj);
+	}
+	if (widename == NULL)
+#endif
+	if (fd < 0)
+	{
+		if (PyBytes_Check(nameobj) || PyByteArray_Check(nameobj)) {
+			if (PyObject_AsCharBuffer(nameobj, &name, NULL) < 0)
+				return -1;
+		}
+		else {
+			PyObject *s;
+			PyObject *u = PyUnicode_FromObject(nameobj);
+
+			if (u == NULL)
+				return -1;
+
+			s = PyUnicode_AsEncodedString(
+				u, Py_FileSystemDefaultEncoding, NULL);
+			Py_DECREF(u);
+			if (s == NULL)
+				return -1;
+			if (!PyBytes_Check(s)) {
+				PyErr_SetString(PyExc_TypeError,
+						"encoder failed to return bytes");
+			}
+			name = PyBytes_AS_STRING(s);
+		}
 	}
 
 	s = mode;
@@ -295,13 +320,15 @@
 			goto error;
 	}
 
+	if (PyObject_SetAttrString((PyObject *)self, "name", nameobj) < 0)
+		goto error;
+
 	goto done;
 
  error:
 	ret = -1;
 
  done:
-	PyMem_Free(name);
 	return ret;
 }
 
@@ -316,6 +343,8 @@
 			PyErr_WriteUnraisable((PyObject*)self);
 	}
 
+	Py_CLEAR(self->dict);
+
 	Py_TYPE(self)->tp_free((PyObject *)self);
 }
 
@@ -404,6 +433,31 @@
 	return PyLong_FromSsize_t(n);
 }
 
+static size_t
+new_buffersize(PyFileIOObject *self, size_t currentsize)
+{
+#ifdef HAVE_FSTAT
+	off_t pos, end;
+	struct stat st;
+	if (fstat(self->fd, &st) == 0) {
+		end = st.st_size;
+		pos = lseek(self->fd, 0L, SEEK_CUR);
+		if (end >= pos && pos >= 0)
+			return currentsize + end - pos + 1;
+		/* Add 1 so if the file were to grow we'd notice. */
+	}
+#endif
+	if (currentsize > SMALLCHUNK) {
+		/* Keep doubling until we reach BIGCHUNK;
+		   then keep adding BIGCHUNK. */
+		if (currentsize <= BIGCHUNK)
+			return currentsize + currentsize;
+		else
+			return currentsize + BIGCHUNK;
+	}
+	return currentsize + SMALLCHUNK;
+}
+
 static PyObject *
 fileio_readall(PyFileIOObject *self)
 {
@@ -416,17 +470,7 @@
 		return NULL;
 
 	while (1) {
-		Py_ssize_t newsize = (total < SMALLCHUNK) ? SMALLCHUNK : total;
-
-		/* Keep doubling until we reach BIGCHUNK;
-		   then keep adding BIGCHUNK. */
-		if (newsize <= BIGCHUNK) {
-			newsize += newsize;
-		}
-		else {
-			/* NOTE: overflow impossible due to limits on BUFSIZ */
-			newsize += BIGCHUNK;
-		}
+		Py_ssize_t newsize = new_buffersize(self, total);
 
 		if (PyBytes_GET_SIZE(result) < newsize) {
 			if (_PyBytes_Resize(&result, newsize) < 0) {
@@ -550,12 +594,6 @@
 
 /* XXX Windows support below is likely incomplete */
 
-#if defined(MS_WIN64) || defined(MS_WINDOWS)
-typedef PY_LONG_LONG Py_off_t;
-#else
-typedef off_t Py_off_t;
-#endif
-
 /* Cribbed from posix_lseek() */
 static PyObject *
 portable_lseek(int fd, PyObject *posobj, int whence)
@@ -722,9 +760,9 @@
 fileio_repr(PyFileIOObject *self)
 {
         if (self->fd < 0)
-		return PyUnicode_FromFormat("_fileio._FileIO(-1)");
+		return PyUnicode_FromFormat("io.FileIO(-1)");
 
-	return PyUnicode_FromFormat("_fileio._FileIO(%d, '%s')",
+	return PyUnicode_FromFormat("io.FileIO(%d, '%s')",
 				   self->fd, mode_string(self));
 }
 
@@ -866,8 +904,8 @@
 };
 
 PyTypeObject PyFileIO_Type = {
-	PyVarObject_HEAD_INIT(&PyType_Type, 0)
-	"_FileIO",
+	PyVarObject_HEAD_INIT(NULL, 0)
+	"FileIO",
 	sizeof(PyFileIOObject),
 	0,
 	(destructor)fileio_dealloc,		/* tp_dealloc */
@@ -890,7 +928,7 @@
 	0,					/* tp_traverse */
 	0,					/* tp_clear */
 	0,					/* tp_richcompare */
-	offsetof(PyFileIOObject, weakreflist),	/* tp_weaklistoffset */
+	offsetof(PyFileIOObject, weakreflist), /* tp_weaklistoffset */
 	0,					/* tp_iter */
 	0,					/* tp_iternext */
 	fileio_methods,				/* tp_methods */
@@ -900,40 +938,9 @@
 	0,					/* tp_dict */
 	0,					/* tp_descr_get */
 	0,					/* tp_descr_set */
-	0,					/* tp_dictoffset */
+	offsetof(PyFileIOObject, dict),         /* tp_dictoffset */
 	fileio_init,				/* tp_init */
 	PyType_GenericAlloc,			/* tp_alloc */
 	fileio_new,				/* tp_new */
 	PyObject_Del,				/* tp_free */
 };
-
-static PyMethodDef module_methods[] = {
-	{NULL, NULL}
-};
-
-static struct PyModuleDef fileiomodule = {
-	PyModuleDef_HEAD_INIT,
-	"_fileio",
-	"Fast implementation of io.FileIO.",
-	-1,
-	module_methods,
-	NULL,
-	NULL,
-	NULL,
-	NULL
-};
-
-PyMODINIT_FUNC
-PyInit__fileio(void)
-{
-	PyObject *m;	/* a module object */
-
-	m = PyModule_Create(&fileiomodule);
-	if (m == NULL)
-		return NULL;
-	if (PyType_Ready(&PyFileIO_Type) < 0)
-		return NULL;
-	Py_INCREF(&PyFileIO_Type);
-	PyModule_AddObject(m, "_FileIO", (PyObject *) &PyFileIO_Type);
-	return m;
-}

Added: python/branches/io-c/Modules/_iobase.c
==============================================================================
--- (empty file)
+++ python/branches/io-c/Modules/_iobase.c	Sun Jan 18 00:13:48 2009
@@ -0,0 +1,798 @@
+#include "Python.h"
+#include "structmember.h"
+#include "_iomodule.h"
+
+/*
+ * IOBase class, an abstract class
+ */
+
+PyDoc_STRVAR(IOBase_doc,
+    "The abstract base class for all I/O classes, acting on streams of\n"
+    "bytes. There is no public constructor.\n"
+    "\n"
+    "This class provides dummy implementations for many methods that\n"
+    "derived classes can override selectively; the default implementations\n"
+    "represent a file that cannot be read, written or seeked.\n"
+    "\n"
+    "Even though IOBase does not declare read, readinto, or write because\n"
+    "their signatures will vary, implementations and clients should\n"
+    "consider those methods part of the interface. Also, implementations\n"
+    "may raise a IOError when operations they do not support are called.\n"
+    "\n"
+    "The basic type used for binary data read from or written to a file is\n"
+    "bytes. bytearrays are accepted too, and in some cases (such as\n"
+    "readinto) needed. Text I/O classes work with str data.\n"
+    "\n"
+    "Note that calling any method (even inquiries) on a closed stream is\n"
+    "undefined. Implementations may raise IOError in this case.\n"
+    "\n"
+    "IOBase (and its subclasses) support the iterator protocol, meaning\n"
+    "that an IOBase object can be iterated over yielding the lines in a\n"
+    "stream.\n"
+    "\n"
+    "IOBase also supports the :keyword:`with` statement. In this example,\n"
+    "fp is closed after the suite of the with statment is complete:\n"
+    "\n"
+    "with open('spam.txt', 'r') as fp:\n"
+    "    fp.write('Spam and eggs!')\n");
+
+/* Use this macro whenever you want to check the internal `closed` status
+   of the IOBase object rather than the virtual `closed` attribute as returned
+   by whatever subclass. */
+
+#define IS_CLOSED(self) \
+    PyObject_HasAttrString(self, "__IOBase_closed")
+
+/* Internal methods */
+static PyObject *
+IOBase_unsupported(const char *message)
+{
+    PyErr_SetString(PyIOExc_UnsupportedOperation, message);
+    return NULL;
+}
+
+/* Positionning */
+
+PyDoc_STRVAR(IOBase_seek_doc,
+    "Change stream position.\n"
+    "\n"
+    "Change the stream position to byte offset offset. offset is\n"
+    "interpreted relative to the position indicated by whence.  Values\n"
+    "for whence are:\n"
+    "\n"
+    "* 0 -- start of stream (the default); offset should be zero or positive\n"
+    "* 1 -- current stream position; offset may be negative\n"
+    "* 2 -- end of stream; offset is usually negative\n"
+    "\n"
+    "Return the new absolute position.");
+
+static PyObject *
+IOBase_seek(PyObject *self, PyObject *args)
+{
+    return IOBase_unsupported("seek");
+}
+
+PyDoc_STRVAR(IOBase_tell_doc,
+             "Return current stream position.");
+
+static PyObject *
+IOBase_tell(PyObject *self, PyObject *args)
+{
+    return PyObject_CallMethod(self, "seek", "ii", 0, 1);
+}
+
+PyDoc_STRVAR(IOBase_truncate_doc,
+    "Truncate file to size bytes.\n"
+    "\n"
+    "Size defaults to the current IO position as reported by tell().  Return\n"
+    "the new size.");
+
+static PyObject *
+IOBase_truncate(PyObject *self, PyObject *args)
+{
+    return IOBase_unsupported("seek");
+}
+
+/* Flush and close methods */
+
+PyDoc_STRVAR(IOBase_flush_doc,
+    "Flush write buffers, if applicable.\n"
+    "\n"
+    "This is not implemented for read-only and non-blocking streams.\n");
+
+static PyObject *
+IOBase_flush(PyObject *self, PyObject *args)
+{
+    /* XXX Should this return the number of bytes written??? */
+    Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(IOBase_close_doc,
+    "Flush and close the IO object.\n"
+    "\n"
+    "This method has no effect if the file is already closed.\n");
+
+static int
+IOBase_closed(PyObject *self)
+{
+    PyObject *res;
+    int closed;
+    /* This gets the derived attribute, which is *not* __IOBase_closed
+       in most cases! */
+    res = PyObject_GetAttr(self, _PyIO_str_closed);
+    closed = PyObject_IsTrue(res);
+    Py_DECREF(res);
+    return closed;
+}
+
+static PyObject *
+IOBase_closed_get(PyObject *self, void *context)
+{
+    return PyBool_FromLong(IS_CLOSED(self));
+}
+
+
+PyObject *
+_PyIOBase_checkClosed(PyObject *self, PyObject *args)
+{
+    if (IOBase_closed(self)) {
+        PyErr_SetString(PyExc_ValueError, "I/O operation on closed file.");
+        return NULL;
+    }
+    if (args == Py_True)
+        return Py_None;
+    else
+        Py_RETURN_NONE;
+}
+
+/* XXX: IOBase thinks it has to maintain its own internal state in
+   `__IOBase_closed` and call flush() by itself, but it is redundant with
+   whatever behaviour a non-trivial derived class will implement. */
+
+static PyObject *
+IOBase_close(PyObject *self, PyObject *args)
+{
+    PyObject *res;
+
+    if (IS_CLOSED(self))
+        Py_RETURN_NONE;
+
+    res = PyObject_CallMethodObjArgs(self, _PyIO_str_flush, NULL);
+    PyObject_SetAttrString(self, "__IOBase_closed", Py_True);
+    if (res == NULL) {
+        /* If flush() fails, just give up */
+        if (PyErr_ExceptionMatches(PyExc_IOError))
+            PyErr_Clear();
+        else
+            return NULL;
+    }
+    Py_XDECREF(res);
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+IOBase_del(PyObject *self, PyObject *args)
+{
+    PyObject *res = NULL;
+    res = PyObject_CallMethodObjArgs(self, _PyIO_str_close, NULL);
+    if (res == NULL) {
+        /* At program exit time, it's possible that globals have already been
+         *  deleted, and then the close() call might fail.  Since there's
+         *  nothing we can do about such failures and they annoy the end
+         *  users, we suppress the traceback.
+         *
+         * XXX: this function can be called at other times and what if the
+         * error is genuine?
+         */
+        PyErr_Clear();
+    }
+    Py_XDECREF(res);
+    Py_RETURN_NONE;
+}
+
+/* Inquiry methods */
+
+PyDoc_STRVAR(IOBase_seekable_doc,
+    "Return whether object supports random access.\n"
+    "\n"
+    "If False, seek(), tell() and truncate() will raise IOError.\n"
+    "This method may need to do a test seek().");
+
+static PyObject *
+IOBase_seekable(PyObject *self, PyObject *args)
+{
+    Py_RETURN_FALSE;
+}
+
+PyObject *
+_PyIOBase_checkSeekable(PyObject *self, PyObject *args)
+{
+    PyObject *res  = PyObject_CallMethodObjArgs(self, _PyIO_str_seekable, NULL);
+    if (res == NULL)
+        return NULL;
+    if (res != Py_True) {
+        Py_CLEAR(res);
+        PyErr_SetString(PyExc_IOError, "File or stream is not seekable.");
+    }
+    if (args == Py_True) {
+        Py_DECREF(res);
+    }
+    return res;
+}
+
+PyDoc_STRVAR(IOBase_readable_doc,
+    "Return whether object was opened for reading.\n"
+    "\n"
+    "If False, read() will raise IOError.");
+
+static PyObject *
+IOBase_readable(PyObject *self, PyObject *args)
+{
+    Py_RETURN_FALSE;
+}
+
+/* May be called with any object */
+PyObject *
+_PyIOBase_checkReadable(PyObject *self, PyObject *args)
+{
+    PyObject *res  = PyObject_CallMethodObjArgs(self, _PyIO_str_readable, NULL);
+    if (res == NULL)
+        return NULL;
+    if (res != Py_True) {
+        Py_CLEAR(res);
+        PyErr_SetString(PyExc_IOError, "File or stream is not readable.");
+    }
+    if (args == Py_True) {
+        Py_DECREF(res);
+    }
+    return res;
+}
+
+PyDoc_STRVAR(IOBase_writable_doc,
+    "Return whether object was opened for writing.\n"
+    "\n"
+    "If False, read() will raise IOError.");
+
+static PyObject *
+IOBase_writable(PyObject *self, PyObject *args)
+{
+    Py_RETURN_FALSE;
+}
+
+/* May be called with any object */
+PyObject *
+_PyIOBase_checkWritable(PyObject *self, PyObject *args)
+{
+    PyObject *res  = PyObject_CallMethodObjArgs(self, _PyIO_str_writable, NULL);
+    if (res == NULL)
+        return NULL;
+    if (res != Py_True) {
+        Py_CLEAR(res);
+        PyErr_SetString(PyExc_IOError, "File or stream is not writable.");
+    }
+    if (args == Py_True) {
+        Py_DECREF(res);
+    }
+    return res;
+}
+
+/* Context manager */
+
+static PyObject *
+IOBase_enter(PyObject *self, PyObject *args)
+{
+    if (_PyIOBase_checkClosed(self, Py_True) == NULL)
+        return NULL;
+
+    Py_INCREF(self);
+    return self;
+}
+
+static PyObject *
+IOBase_exit(PyObject *self, PyObject *args)
+{
+    return PyObject_CallMethodObjArgs(self, _PyIO_str_close, NULL);
+}
+
+/* Lower-level APIs */
+
+/* XXX Should these be present even if unimplemented? */
+
+PyDoc_STRVAR(IOBase_fileno_doc,
+    "Returns underlying file descriptor if one exists.\n"
+    "\n"
+    "An IOError is raised if the IO object does not use a file descriptor.\n");
+
+static PyObject *
+IOBase_fileno(PyObject *self, PyObject *args)
+{
+    return IOBase_unsupported("fileno");
+}
+
+PyDoc_STRVAR(IOBase_isatty_doc,
+    "Return whether this is an 'interactive' stream.\n"
+    "\n"
+    "Return False if it can't be determined.\n");
+
+static PyObject *
+IOBase_isatty(PyObject *self, PyObject *args)
+{
+    if (_PyIOBase_checkClosed(self, Py_True) == NULL)
+        return NULL;
+    Py_RETURN_FALSE;
+}
+
+/* Readline(s) and writelines */
+
+PyDoc_STRVAR(IOBase_readline_doc,
+    "Read and return a line from the stream.\n"
+    "\n"
+    "If limit is specified, at most limit bytes will be read.\n"
+    "\n"
+    "The line terminator is always b'\n' for binary files; for text\n"
+    "files, the newlines argument to open can be used to select the line\n"
+    "terminator(s) recognized.\n");
+
+static PyObject *
+IOBase_readline(PyObject *self, PyObject *args)
+{
+    /* For backwards compatibility, a (slowish) readline(). */
+
+    Py_ssize_t limit = -1;
+    int has_peek = 0;
+    PyObject *buffer, *result;
+    Py_ssize_t old_size = -1;
+
+    if (!PyArg_ParseTuple(args, "|n:readline", &limit)) {
+        return NULL;
+    }
+
+    if (_PyIOBase_checkClosed(self, Py_True) == NULL)
+        return NULL;
+
+    if (PyObject_HasAttrString(self, "peek"))
+        has_peek = 1;
+
+    buffer = PyByteArray_FromStringAndSize(NULL, 0);
+    if (buffer == NULL)
+        return NULL;
+
+    while (limit < 0 || Py_SIZE(buffer) < limit) {
+        Py_ssize_t nreadahead = 1;
+        PyObject *b;
+
+        if (has_peek) {
+            PyObject *readahead = PyObject_CallMethod(self, "peek", "i", 1);
+            if (readahead == NULL)
+                goto fail;
+            if (!PyBytes_Check(readahead)) {
+                PyErr_Format(PyExc_IOError,
+                             "peek() should have returned a bytes object, "
+                             "not '%.200s'", Py_TYPE(readahead)->tp_name);
+                Py_DECREF(readahead);
+                goto fail;
+            }
+            if (PyBytes_GET_SIZE(readahead) > 0) {
+                Py_ssize_t n = 0;
+                const char *buf = PyBytes_AS_STRING(readahead);
+                if (limit >= 0) {
+                    do {
+                        if (n >= PyBytes_GET_SIZE(readahead) || n >= limit)
+                            break;
+                        if (buf[n++] == '\n')
+                            break;
+                    } while (1);
+                }
+                else {
+                    do {
+                        if (n >= PyBytes_GET_SIZE(readahead))
+                            break;
+                        if (buf[n++] == '\n')
+                            break;
+                    } while (1);
+                }
+                nreadahead = n;
+            }
+            Py_DECREF(readahead);
+        }
+
+        b = PyObject_CallMethod(self, "read", "n", nreadahead);
+        if (b == NULL)
+            goto fail;
+        if (!PyBytes_Check(b)) {
+            PyErr_Format(PyExc_IOError,
+                         "read() should have returned a bytes object, "
+                         "not '%.200s'", Py_TYPE(b)->tp_name);
+            Py_DECREF(b);
+            goto fail;
+        }
+        if (PyBytes_GET_SIZE(b) == 0) {
+            Py_DECREF(b);
+            break;
+        }
+
+        old_size = PyByteArray_GET_SIZE(buffer);
+        PyByteArray_Resize(buffer, old_size + PyBytes_GET_SIZE(b));
+        memcpy(PyByteArray_AS_STRING(buffer) + old_size,
+               PyBytes_AS_STRING(b), PyBytes_GET_SIZE(b));
+
+        Py_DECREF(b);
+
+        if (PyByteArray_AS_STRING(buffer)[PyByteArray_GET_SIZE(buffer) - 1] == '\n')
+            break;
+    }
+
+    result = PyBytes_FromStringAndSize(PyByteArray_AS_STRING(buffer),
+                                       PyByteArray_GET_SIZE(buffer));
+    Py_DECREF(buffer);
+    return result;
+  fail:
+    Py_DECREF(buffer);
+    return NULL;
+}
+
+static PyObject *
+IOBase_iter(PyObject *self)
+{
+    if (_PyIOBase_checkClosed(self, Py_True) == NULL)
+        return NULL;
+
+    Py_INCREF(self);
+    return self;
+}
+
+static PyObject *
+IOBase_iternext(PyObject *self)
+{
+    PyObject *line = PyObject_CallMethodObjArgs(self, _PyIO_str_readline, NULL);
+
+    if (line == NULL)
+        return NULL;
+
+    if (PyObject_Size(line) == 0) {
+        Py_DECREF(line);
+        return NULL;
+    }
+
+    return line;
+}
+
+PyDoc_STRVAR(IOBase_readlines_doc,
+    "Return a list of lines from the stream.\n"
+    "\n"
+    "hint can be specified to control the number of lines read: no more\n"
+    "lines will be read if the total size (in bytes/characters) of all\n"
+    "lines so far exceeds hint.");
+
+static PyObject *
+IOBase_readlines(PyObject *self, PyObject *args)
+{
+    Py_ssize_t hint = -1, length = 0;
+    PyObject *hintobj = Py_None, *result;
+
+    if (!PyArg_ParseTuple(args, "|O:readlines", &hintobj)) {
+        return NULL;
+    }
+    if (hintobj != Py_None) {
+        hint = PyNumber_AsSsize_t(hintobj, PyExc_ValueError);
+        if (hint == -1 && PyErr_Occurred())
+            return NULL;
+    }
+
+    result = PyList_New(0);
+    if (result == NULL)
+        return NULL;
+
+    if (hint <= 0) {
+        PyObject *ret = PyObject_CallMethod(result, "extend", "O", self);
+        if( ret == NULL) {
+            Py_DECREF(result);
+            return NULL;
+        }
+        Py_DECREF(ret);
+        return result;
+    }
+
+    while (1) {
+        PyObject *line = PyIter_Next(self);
+        if (line == NULL) {
+            if (PyErr_Occurred()) {
+                Py_DECREF(result);
+                return NULL;
+            }
+            else
+                break; /* SopIteration raised */
+        }
+
+        if (PyList_Append(result, line) < 0) {
+            Py_DECREF(line);
+            Py_DECREF(result);
+            return NULL;
+        }
+        length += PyObject_Size(line);
+        Py_DECREF(line);
+
+        if (length > hint)
+            break;
+    }
+    return result;
+}
+
+static PyObject *
+IOBase_writelines(PyObject *self, PyObject *args)
+{
+    PyObject *lines, *iter, *res;
+
+    if (!PyArg_ParseTuple(args, "O:writelines", &lines)) {
+        return NULL;
+    }
+
+    if (_PyIOBase_checkClosed(self, Py_True) == NULL)
+        return NULL;
+
+    iter = PyObject_GetIter(lines);
+    if (iter == NULL)
+        return NULL;
+
+    while (1) {
+        PyObject *line = PyIter_Next(iter);
+        if(line == NULL) {
+            if (PyErr_Occurred()) {
+                Py_DECREF(iter);
+                return NULL;
+            }
+            else
+                break; /* Stop Iteration */
+        }
+
+        res = PyObject_CallMethodObjArgs(self, _PyIO_str_write, line, NULL);
+        Py_DECREF(line);
+        if (res == NULL) {
+            Py_DECREF(iter);
+            return NULL;
+        }
+        Py_DECREF(res);
+    }
+    Py_RETURN_NONE;
+}
+
+static PyMethodDef IOBase_methods[] = {
+    {"seek", IOBase_seek, METH_VARARGS, IOBase_seek_doc},
+    {"tell", IOBase_tell, METH_NOARGS, IOBase_tell_doc},
+    {"truncate", IOBase_truncate, METH_VARARGS, IOBase_truncate_doc},
+    {"flush", IOBase_flush, METH_NOARGS, IOBase_flush_doc},
+    {"close", IOBase_close, METH_NOARGS, IOBase_close_doc},
+
+    {"seekable", IOBase_seekable, METH_NOARGS, IOBase_seekable_doc},
+    {"readable", IOBase_readable, METH_NOARGS, IOBase_readable_doc},
+    {"writable", IOBase_writable, METH_NOARGS, IOBase_writable_doc},
+
+    {"_checkClosed",   _PyIOBase_checkClosed, METH_NOARGS},
+    {"_checkSeekable", _PyIOBase_checkSeekable, METH_NOARGS},
+    {"_checkReadable", _PyIOBase_checkReadable, METH_NOARGS},
+    {"_checkWritable", _PyIOBase_checkWritable, METH_NOARGS},
+
+    {"fileno", IOBase_fileno, METH_NOARGS, IOBase_fileno_doc},
+    {"isatty", IOBase_isatty, METH_NOARGS, IOBase_isatty_doc},
+
+    {"__del__", IOBase_del, METH_NOARGS},
+    {"__enter__", IOBase_enter, METH_NOARGS},
+    {"__exit__", IOBase_exit, METH_VARARGS},
+
+    {"readline", IOBase_readline, METH_VARARGS, IOBase_readline_doc},
+    {"readlines", IOBase_readlines, METH_VARARGS, IOBase_readlines_doc},
+    {"writelines", IOBase_writelines, METH_VARARGS},
+
+    {NULL, NULL}
+};
+
+static PyGetSetDef IOBase_getset[] = {
+    {"closed", (getter)IOBase_closed_get, NULL, NULL},
+    {0}
+};
+
+
+PyTypeObject PyIOBase_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "IOBase",                   /*tp_name*/
+    0,                          /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    0,                          /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    IOBase_doc,                 /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    0,                          /* tp_weaklistoffset */
+    IOBase_iter,                /* tp_iter */
+    IOBase_iternext,            /* tp_iternext */
+    IOBase_methods,             /* tp_methods */
+    0,                          /* tp_members */
+    IOBase_getset,              /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    0,                          /* tp_dictoffset */
+    0,                          /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+    0,                          /* tp_free */
+    0,                          /* tp_is_gc */
+    0,                          /* tp_bases */
+    0,                          /* tp_mro */
+    0,                          /* tp_cache */
+    0,                          /* tp_subclasses */
+    0,                          /* tp_weaklist */
+    0,                          /* tp_del */
+};
+
+
+
+/*
+ * RawIOBase class, Inherits from IOBase.
+ */
+PyDoc_STRVAR(RawIOBase_doc,
+             "Base class for raw binary I/O.");
+
+/*
+ * The read() method is implemented by calling readinto(); derived classes
+ * that want to support read() only need to implement readinto() as a
+ * primitive operation.  In general, readinto() can be more efficient than
+ * read().
+ *
+ * (It would be tempting to also provide an implementation of readinto() in
+ * terms of read(), in case the latter is a more suitable primitive operation,
+ * but that would lead to nasty recursion in case a subclass doesn't implement
+ * either.)
+*/
+
+static PyObject *
+RawIOBase_read(PyObject *self, PyObject *args)
+{
+    Py_ssize_t n = -1;
+    PyObject *b, *res;
+
+    if (!PyArg_ParseTuple(args, "|n:read", &n)) {
+        return NULL;
+    }
+
+    if (n < 0)
+        return PyObject_CallMethod(self, "readall", NULL);
+
+    /* TODO: allocate a bytes object directly instead and manually construct
+       a writable memoryview pointing to it. */
+    b = PyByteArray_FromStringAndSize(NULL, n);
+    if (b == NULL)
+        return NULL;
+
+    res = PyObject_CallMethodObjArgs(self, _PyIO_str_readinto, b, NULL);
+    if (res == NULL) {
+        Py_DECREF(b);
+        return NULL;
+    }
+
+    n = PyNumber_AsSsize_t(res, PyExc_ValueError);
+    Py_DECREF(res);
+    if (n == -1 && PyErr_Occurred()) {
+        Py_DECREF(b);
+        return NULL;
+    }
+
+    res = PyBytes_FromStringAndSize(PyByteArray_AsString(b), n);
+    Py_DECREF(b);
+    return res;
+}
+
+
+PyDoc_STRVAR(RawIOBase_readall_doc,
+             "Read until EOF, using multiple read() call.");
+
+static PyObject *
+RawIOBase_readall(PyObject *self, PyObject *args)
+{
+    PyObject *b = NULL;
+    Py_ssize_t cursize = 0;
+
+    while (1) {
+        Py_ssize_t length;
+        PyObject *data = PyObject_CallMethod(self, "read",
+                                             "i", DEFAULT_BUFFER_SIZE);
+
+        if (!data) {
+            Py_XDECREF(b);
+            return NULL;
+        }
+
+        if (!PyBytes_Check(data)) {
+            Py_XDECREF(b);
+            Py_DECREF(data);
+            PyErr_SetString(PyExc_TypeError, "read() should return bytes");
+            return NULL;
+        }
+
+        length = Py_SIZE(data);
+
+        if (b == NULL)
+            b = data;
+        else if (length != 0) {
+
+            _PyBytes_Resize(&b, cursize + length);
+            if (b == NULL) {
+                Py_DECREF(data);
+                return NULL;
+            }
+
+            memcpy(PyBytes_AS_STRING(b) + cursize,
+                   PyBytes_AS_STRING(data), length);
+            Py_DECREF(data);
+        }
+
+        if (length == 0)
+            break;
+    }
+
+    return b;
+
+}
+
+static PyMethodDef RawIOBase_methods[] = {
+    {"read", RawIOBase_read, METH_VARARGS},
+    {"readall", RawIOBase_readall, METH_NOARGS, RawIOBase_readall_doc},
+    {NULL, NULL}
+};
+
+PyTypeObject PyRawIOBase_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "RawIOBase",                /*tp_name*/
+    0,                          /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    0,                          /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    RawIOBase_doc,              /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    0,                          /* tp_weaklistoffset */
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    RawIOBase_methods,          /* tp_methods */
+    0,                          /* tp_members */
+    0,                          /* tp_getset */
+    &PyIOBase_Type,             /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    0,                          /* tp_dictoffset */
+    0,                          /* tp_init */
+    0,                          /* tp_alloc */
+    0,                          /* tp_new */
+};

Added: python/branches/io-c/Modules/_iomodule.h
==============================================================================
--- (empty file)
+++ python/branches/io-c/Modules/_iomodule.h	Sun Jan 18 00:13:48 2009
@@ -0,0 +1,117 @@
+/*
+ * Temporarily rename symbols, to avoid mismatches with the main executable
+ */
+#define PyRawIOBase_Type _newio_PyRawIOBase_Type
+#define PyFileIO_Type _newio_PyFileIO_Type
+#define PyBytesIO_Type _newio_PyBytesIO_Type
+#define PyIOBase_Type _newio_PyIOBase_Type
+#define PyRawIOBase_Type _newio_PyRawIOBase_Type
+#define PyBufferedIOBase_Type _newio_PyBufferedIOBase_Type
+#define PyBufferedReader_Type _newio_PyBufferedReader_Type
+#define PyBufferedWriter_Type _newio_PyBufferedWriter_Type
+#define PyBufferedRWPair_Type _newio_PyBufferedRWPair_Type
+#define PyBufferedRandom_Type _newio_PyBufferedRandom_Type
+#define PyTextIOWrapper_Type _newio_PyTextIOWrapper_Type
+#define PyIncrementalNewlineDecoder_Type _newio_PyIncrementalNewlineDecoder_Type
+
+/*
+ * Declarations shared between the different parts of the io module
+ */
+
+extern PyTypeObject PyFileIO_Type;
+extern PyTypeObject PyBytesIO_Type;
+extern PyTypeObject PyIOBase_Type;
+extern PyTypeObject PyRawIOBase_Type;
+extern PyTypeObject PyBufferedIOBase_Type;
+extern PyTypeObject PyBufferedReader_Type;
+extern PyTypeObject PyBufferedWriter_Type;
+extern PyTypeObject PyBufferedRWPair_Type;
+extern PyTypeObject PyBufferedRandom_Type;
+extern PyTypeObject PyTextIOWrapper_Type;
+extern PyTypeObject PyIncrementalNewlineDecoder_Type;
+
+/* These functions are used as METH_NOARGS methods, are normally called
+ * with args=NULL, and return a new reference.
+ * BUT when args=Py_True is passed, they return a borrowed reference.
+ */
+extern PyObject* _PyIOBase_checkReadable(PyObject *self, PyObject *args);
+extern PyObject* _PyIOBase_checkWritable(PyObject *self, PyObject *args);
+extern PyObject* _PyIOBase_checkSeekable(PyObject *self, PyObject *args);
+extern PyObject* _PyIOBase_checkClosed(PyObject *self, PyObject *args);
+
+extern PyObject* PyIOExc_UnsupportedOperation;
+
+#define DEFAULT_BUFFER_SIZE (8 * 1024)  /* bytes */
+
+typedef struct {
+    PyException_HEAD
+    PyObject *myerrno;
+    PyObject *strerror;
+    PyObject *filename; /* Not used, but part of the IOError object */
+    Py_ssize_t written;
+} PyBlockingIOErrorObject;
+PyObject *PyExc_BlockingIOError;
+
+
+/*
+ * Offset type for positioning.
+ */
+
+#if defined(MS_WIN64) || defined(MS_WINDOWS)
+
+/* Windows uses long long for offsets */
+typedef PY_LONG_LONG Py_off_t;
+# define PyLong_AsOff_t     PyLong_AsLongLong
+# define PyLong_FromOff_t   PyLong_FromLongLong
+# define PY_OFF_T_MAX       PY_LLONG_MAX
+# define PY_OFF_T_MIN       PY_LLONG_MIN
+
+#else
+
+/* Other platforms use off_t */
+typedef off_t Py_off_t;
+#if (SIZEOF_OFF_T == SIZEOF_SIZE_T)
+# define PyLong_AsOff_t     PyLong_AsSsize_t
+# define PyLong_FromOff_t   PyLong_FromSsize_t
+# define PY_OFF_T_MAX       PY_SSIZE_T_MAX
+# define PY_OFF_T_MIN       PY_SSIZE_T_MIN
+#elif (SIZEOF_OFF_T == SIZEOF_LONG_LONG)
+# define PyLong_AsOff_t     PyLong_AsLongLong
+# define PyLong_FromOff_t   PyLong_FromLongLong
+# define PY_OFF_T_MAX       PY_LLONG_MAX
+# define PY_OFF_T_MIN       PY_LLONG_MIN
+#elif (SIZEOF_OFF_T == SIZEOF_LONG)
+# define PyLong_AsOff_t     PyLong_AsLong
+# define PyLong_FromOff_t   PyLong_FromLong
+# define PY_OFF_T_MAX       LONG_MAX
+# define PY_OFF_T_MIN       LONG_MIN
+#else
+# error off_t does not match either size_t, long, or long long!
+#endif
+
+#endif
+
+extern Py_off_t PyNumber_AsOff_t(PyObject *item, PyObject *err);
+
+/* Implementation details */
+
+extern PyObject *_PyIO_str_close;
+extern PyObject *_PyIO_str_closed;
+extern PyObject *_PyIO_str_decode;
+extern PyObject *_PyIO_str_encode;
+extern PyObject *_PyIO_str_fileno;
+extern PyObject *_PyIO_str_flush;
+extern PyObject *_PyIO_str_getstate;
+extern PyObject *_PyIO_str_isatty;
+extern PyObject *_PyIO_str_newlines;
+extern PyObject *_PyIO_str_read;
+extern PyObject *_PyIO_str_read1;
+extern PyObject *_PyIO_str_readable;
+extern PyObject *_PyIO_str_readinto;
+extern PyObject *_PyIO_str_readline;
+extern PyObject *_PyIO_str_seek;
+extern PyObject *_PyIO_str_seekable;
+extern PyObject *_PyIO_str_tell;
+extern PyObject *_PyIO_str_truncate;
+extern PyObject *_PyIO_str_writable;
+extern PyObject *_PyIO_str_write;

Added: python/branches/io-c/Modules/_textio.c
==============================================================================
--- (empty file)
+++ python/branches/io-c/Modules/_textio.c	Sun Jan 18 00:13:48 2009
@@ -0,0 +1,2185 @@
+#include "Python.h"
+#include "structmember.h"
+#include "_iomodule.h"
+
+/* TextIOBase */
+
+PyDoc_STRVAR(TextIOBase_doc,
+    "Base class for text I/O.\n"
+    "\n"
+    "This class provides a character and line based interface to stream\n"
+    "I/O. There is no readinto method because Python's character strings\n"
+    "are immutable. There is no public constructor.\n"
+    );
+
+static PyObject *
+_unsupported(const char *message)
+{
+    PyErr_SetString(PyIOExc_UnsupportedOperation, message);
+    return NULL;
+}
+
+static PyObject *
+TextIOBase_read(PyObject *self, PyObject *args)
+{
+    return _unsupported("read");
+}
+
+static PyObject *
+TextIOBase_write(PyObject *self, PyObject *args)
+{
+    return _unsupported("read");
+}
+
+static PyObject *
+TextIOBase_readline(PyObject *self, PyObject *args)
+{
+    return _unsupported("read");
+}
+
+/* XXX properties: encoding, newlines */
+
+
+/* IncrementalNewlineDecoder */
+
+PyDoc_STRVAR(IncrementalNewlineDecoder_doc,
+    "Codec used when reading a file in universal newlines mode.  It wraps\n"
+    "another incremental decoder, translating \\r\\n and \\r into \\n.  It also\n"
+    "records the types of newlines encountered.  When used with\n"
+    "translate=False, it ensures that the newline sequence is returned in\n"
+    "one piece.\n"
+    );
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *decoder;
+    PyObject *errors;
+    int pendingcr:1;
+    int translate:1;
+    unsigned int seennl:3;
+} PyNewLineDecoderObject;
+
+static int
+IncrementalNewlineDecoder_init(PyNewLineDecoderObject *self, 
+                               PyObject *args, PyObject *kwds)
+{
+    PyObject *decoder;
+    int translate;
+    PyObject *errors = NULL;
+    char *kwlist[] = {"decoder", "translate", "errors", NULL};
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "Oi|O:IncrementalNewlineDecoder",
+                                     kwlist, &decoder, &translate, &errors))
+        return -1;
+
+    self->decoder = decoder;
+    Py_INCREF(decoder);
+
+    if (errors == NULL) {
+        self->errors = PyUnicode_FromString("strict");
+        if (self->errors == NULL)
+            return -1;
+    }
+    else {
+        Py_INCREF(errors);
+        self->errors = errors;
+    }
+
+    self->translate = translate;
+    self->seennl = 0;
+    self->pendingcr = 0;
+
+    return 0;
+}
+
+static void
+IncrementalNewlineDecoder_dealloc(PyNewLineDecoderObject *self)
+{
+    Py_CLEAR(self->decoder);
+    Py_CLEAR(self->errors);
+    Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+#define SEEN_CR   1
+#define SEEN_LF   2
+#define SEEN_CRLF 4
+#define SEEN_ALL (SEEN_CR | SEEN_LF | SEEN_CRLF)
+
+static PyObject *
+_IncrementalNewlineDecoder_decode(PyNewLineDecoderObject *self, 
+                                  PyObject *input, int final)
+{
+    PyObject *output;
+    Py_ssize_t output_len;
+
+    if (self->decoder == NULL) {
+        PyErr_SetString(PyExc_ValueError,
+                        "IncrementalNewlineDecoder.__init__ not called");
+        return NULL;
+    }
+
+    /* decode input (with the eventual \r from a previous pass) */
+    output = PyObject_CallMethodObjArgs(self->decoder, _PyIO_str_decode,
+                                        input, final ? Py_True : Py_False, NULL);
+    if (output == NULL)
+        return NULL;
+
+    if (!PyUnicode_Check(output)) {
+        PyErr_SetString(PyExc_TypeError,
+                        "decoder should return a string result");
+        goto error;
+    }
+
+    output_len = PyUnicode_GET_SIZE(output);
+    if (self->pendingcr && (final || output_len > 0)) {
+        Py_UNICODE *out;
+        PyObject *modified = PyUnicode_FromUnicode(NULL, output_len + 1);
+        if (modified == NULL)
+            goto error;
+        out = PyUnicode_AS_UNICODE(modified);
+        out[0] = '\r';
+        memcpy(out + 1, PyUnicode_AS_UNICODE(output),
+               output_len * sizeof(Py_UNICODE));
+        Py_DECREF(output);
+        output = modified;
+        self->pendingcr = 0;
+        output_len++;
+    }
+
+    /* retain last \r even when not translating data:
+     * then readline() is sure to get \r\n in one pass
+     */
+    if (!final) {
+        if (output_len > 0 
+            && PyUnicode_AS_UNICODE(output)[output_len - 1] == '\r') {
+
+            if (Py_REFCNT(output) == 1) {
+                if (PyUnicode_Resize(&output, output_len - 1) < 0)
+                    goto error;
+            }
+            else {
+                PyObject *modified = PyUnicode_FromUnicode(
+                    PyUnicode_AS_UNICODE(output),
+                    output_len - 1);
+                if (modified == NULL)
+                    goto error;
+                Py_DECREF(output);
+                output = modified;
+            }
+            self->pendingcr = 1;
+        }
+    }
+
+    /* Record which newlines are read and do newline translation if desired,
+       all in one pass. */
+    {
+        Py_UNICODE *in_str;
+        Py_ssize_t len;
+        int seennl = self->seennl;
+        int only_lf;
+
+        in_str = PyUnicode_AS_UNICODE(output);
+        len = PyUnicode_GET_SIZE(output);
+
+        if (len == 0)
+            return output;
+
+        /* If, up to now, newlines are consistently \n, do a quick check
+           for the \r *byte* with the libc's optimized memchr.
+           */
+        only_lf = ((seennl == SEEN_LF)
+                && !memchr(in_str, '\r', len * sizeof(Py_UNICODE)));
+
+        if (!self->translate) {
+            Py_UNICODE *s, *end;
+            if (seennl == SEEN_ALL)
+                goto endscan;
+            if (only_lf)
+                goto endscan;
+            s = in_str;
+            end = in_str + len;
+            for (;;) {
+                Py_UNICODE c;
+                /* Fast loop for non-control characters */
+                while (*s > '\r')
+                    s++;
+                c = *s++;
+                if (c == '\n')
+                    seennl |= SEEN_LF;
+                else if (c == '\r') {
+                    if (*s == '\n') {
+                        seennl |= SEEN_CRLF;
+                        s++;
+                    }
+                    else
+                        seennl |= SEEN_CR;
+                }
+                if (s > end)
+                    break;
+                if (seennl == SEEN_ALL)
+                    break;
+            }
+        endscan:
+            ;
+        }
+        else if (!only_lf) {
+            PyObject *translated = NULL;
+            Py_UNICODE *out_str;
+            Py_UNICODE *in, *out, *end;
+            if (Py_REFCNT(output) != 1) {
+                /* We could try to optimize this so that we only do a copy
+                   when there is something to translate. On the other hand,
+                   most decoders should only output non-shared strings, i.e.
+                   translation is done in place. */
+                translated = PyUnicode_FromUnicode(NULL, len);
+                if (translated == NULL)
+                    goto error;
+                assert(Py_REFCNT(translated) == 1);
+                memcpy(PyUnicode_AS_UNICODE(translated),
+                       PyUnicode_AS_UNICODE(output),
+                       len * sizeof(Py_UNICODE));
+            }
+            else {
+                translated = output;
+            }
+            out_str = PyUnicode_AS_UNICODE(translated);
+            in = in_str;
+            out = out_str;
+            end = in_str + len;
+            for (;;) {
+                Py_UNICODE c;
+                /* Fast loop for non-control characters */
+                while ((c = *in++) > '\r')
+                    *out++ = c;
+                if (c == '\n') {
+                    *out++ = c;
+                    seennl |= SEEN_LF;
+                    continue;
+                }
+                if (c == '\r') {
+                    if (*in == '\n') {
+                        in++;
+                        seennl |= SEEN_CRLF;
+                    }
+                    else
+                        seennl |= SEEN_CR;
+                    *out++ = '\n';
+                    continue;
+                }
+                if (in > end)
+                    break;
+                *out++ = c;
+            }
+            if (translated != output) {
+                Py_DECREF(output);
+                output = translated;
+            }
+            if (out - out_str != len) {
+                if (PyUnicode_Resize(&output, out - out_str) < 0)
+                    goto error;
+            }
+        }
+        self->seennl |= seennl;
+    }
+
+    return output;
+
+  error:
+    Py_DECREF(output);
+    return NULL;
+}
+
+static PyObject *
+IncrementalNewlineDecoder_decode(PyNewLineDecoderObject *self, 
+                                 PyObject *args, PyObject *kwds)
+{
+    char *kwlist[] = {"input", "final", NULL};
+    PyObject *input;
+    int final = 0;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|i:IncrementalNewlineDecoder",
+                                     kwlist, &input, &final))
+        return NULL;
+    return _IncrementalNewlineDecoder_decode(self, input, final);
+}
+
+static PyObject *
+IncrementalNewlineDecoder_getstate(PyNewLineDecoderObject *self, PyObject *args)
+{
+    PyObject *state = PyObject_CallMethodObjArgs(self->decoder,
+                                                 _PyIO_str_getstate, NULL);
+    PyObject *buffer;
+    unsigned PY_LONG_LONG flag;
+
+    if (state == NULL)
+        return NULL;
+
+    if (!PyArg_Parse(state, "(OK)", &buffer, &flag)) {
+        Py_DECREF(state);
+        return NULL;
+    }
+    Py_INCREF(buffer);
+    Py_DECREF(state);
+    flag <<= 1;
+    if (self->pendingcr)
+        flag |= 1;
+    return Py_BuildValue("NK", buffer, flag);
+}
+
+static PyObject *
+IncrementalNewlineDecoder_setstate(PyNewLineDecoderObject *self, PyObject *state)
+{
+    PyObject *buffer;
+    unsigned PY_LONG_LONG flag;
+
+    if (!PyArg_Parse(state, "(OK)", &buffer, &flag))
+        return NULL;
+
+    self->pendingcr = (int) flag & 1;
+    flag >>= 1;
+
+    return PyObject_CallMethod(self->decoder, "setstate", "((OK))", buffer, flag);
+}
+
+static PyObject *
+IncrementalNewlineDecoder_reset(PyNewLineDecoderObject *self, PyObject *args)
+{
+    self->seennl = 0;
+    self->pendingcr = 0;
+    return PyObject_CallMethod(self->decoder, "reset", NULL);
+}
+
+static PyObject *
+IncrementalNewlineDecoder_newlines_get(PyNewLineDecoderObject *self, void *context)
+{
+    switch (self->seennl) {
+    case SEEN_CR:
+        return PyUnicode_FromString("\r");
+    case SEEN_LF:
+        return PyUnicode_FromString("\n");
+    case SEEN_CRLF:
+        return PyUnicode_FromString("\r\n");
+    case SEEN_CR | SEEN_LF:
+        return Py_BuildValue("ss", "\r", "\n");
+    case SEEN_CR | SEEN_CRLF:
+        return Py_BuildValue("ss", "\r", "\r\n");
+    case SEEN_LF | SEEN_CRLF:
+        return Py_BuildValue("ss", "\n", "\r\n");
+    case SEEN_CR | SEEN_LF | SEEN_CRLF:
+        return Py_BuildValue("sss", "\r", "\n", "\r\n");
+    default:
+        Py_RETURN_NONE;
+   }
+
+}
+
+
+static PyMethodDef IncrementalNewlineDecoder_methods[] = {
+    {"decode", (PyCFunction)IncrementalNewlineDecoder_decode, METH_VARARGS|METH_KEYWORDS},
+    {"getstate", (PyCFunction)IncrementalNewlineDecoder_getstate, METH_NOARGS},
+    {"setstate", (PyCFunction)IncrementalNewlineDecoder_setstate, METH_O},
+    {"reset", (PyCFunction)IncrementalNewlineDecoder_reset, METH_NOARGS},
+    {0}
+};
+
+static PyGetSetDef IncrementalNewlineDecoder_getset[] = {
+    {"newlines", (getter)IncrementalNewlineDecoder_newlines_get, NULL, NULL},
+    {0}
+};
+
+PyTypeObject PyIncrementalNewlineDecoder_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "IncrementalNewlineDecoder", /*tp_name*/
+    sizeof(PyNewLineDecoderObject), /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    (destructor)IncrementalNewlineDecoder_dealloc, /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    IncrementalNewlineDecoder_doc,          /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    0,                          /*tp_weaklistoffset*/
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    IncrementalNewlineDecoder_methods, /* tp_methods */
+    0,                          /* tp_members */
+    IncrementalNewlineDecoder_getset, /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    0,                          /* tp_dictoffset */
+    (initproc)IncrementalNewlineDecoder_init, /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+};
+
+
+/* TextIOWrapper */
+
+PyDoc_STRVAR(TextIOWrapper_doc,
+    "Character and line based layer over a BufferedIOBase object, buffer.\n"
+    "\n"
+    "encoding gives the name of the encoding that the stream will be\n"
+    "decoded or encoded with. It defaults to locale.getpreferredencoding.\n"
+    "\n"
+    "errors determines the strictness of encoding and decoding (see the\n"
+    "codecs.register) and defaults to \"strict\".\n"
+    "\n"
+    "newline can be None, '', '\\n', '\\r', or '\\r\\n'.  It controls the\n"
+    "handling of line endings. If it is None, universal newlines is\n"
+    "enabled.  With this enabled, on input, the lines endings '\\n', '\\r',\n"
+    "or '\\r\\n' are translated to '\\n' before being returned to the\n"
+    "caller. Conversely, on output, '\\n' is translated to the system\n"
+    "default line seperator, os.linesep. If newline is any other of its\n"
+    "legal values, that newline becomes the newline when the file is read\n"
+    "and it is returned untranslated. On output, '\\n' is converted to the\n"
+    "newline.\n"
+    "\n"
+    "If line_buffering is True, a call to flush is implied when a call to\n"
+    "write contains a newline character."
+    );
+
+typedef PyObject *
+        (*encodefunc_t)(PyObject *, PyObject *);
+
+typedef struct
+{
+    PyObject_HEAD
+    int ok; /* initialized? */
+    Py_ssize_t chunk_size;
+    PyObject *buffer;
+    PyObject *encoding;
+    PyObject *encoder;
+    PyObject *decoder;
+    PyObject *readnl;
+    PyObject *errors;
+    const char *writenl; /* utf-8 encoded, NULL stands for \n */
+    int line_buffering:1;
+    int readuniversal:1;
+    int readtranslate:1;
+    int writetranslate:1;
+    int seekable:1;
+    int telling:1;
+    /* Specialized encoding func (see below) */
+    encodefunc_t encodefunc;
+
+    /* Reads and writes are internally buffered in order to speed things up.
+       However, any read will first flush the write buffer if itsn't empty.
+    
+       Please also note that text to be written is first encoded before being
+       buffered. This is necessary so that encoding errors are immediately
+       reported to the caller, but it unfortunately means that the
+       IncrementalEncoder (whose encode() method is always written in Python)
+       becomes a bottleneck for small writes.
+    */
+    PyObject *decoded_chars;       /* buffer for text returned from decoder */
+    Py_ssize_t decoded_chars_used; /* offset into _decoded_chars for read() */
+    PyObject *pending_bytes;       /* list of bytes objects waiting to be
+                                      written, or NULL */
+    Py_ssize_t pending_bytes_count;
+    PyObject *snapshot;
+    /* snapshot is either None, or a tuple (dec_flags, next_input) where
+     * dec_flags is the second (integer) item of the decoder state and
+     * next_input is the chunk of input bytes that comes next after the
+     * snapshot point.  We use this to reconstruct decoder states in tell().
+     */
+
+    PyObject *weakreflist;
+    PyObject *dict;
+} PyTextIOWrapperObject;
+
+
+/* A couple of specialized cases in order to bypass the slow incremental
+   encoding methods for the most popular encodings. */
+
+static PyObject *
+ascii_encode(PyTextIOWrapperObject *self, PyObject *text)
+{
+    return PyUnicode_EncodeASCII(PyUnicode_AS_UNICODE(text),
+                                 PyUnicode_GET_SIZE(text),
+                                 PyBytes_AS_STRING(self->errors));
+}
+
+static PyObject *
+utf16be_encode(PyTextIOWrapperObject *self, PyObject *text)
+{
+    return PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(text),
+                                 PyUnicode_GET_SIZE(text),
+                                 PyBytes_AS_STRING(self->errors), 1);
+}
+
+static PyObject *
+utf16le_encode(PyTextIOWrapperObject *self, PyObject *text)
+{
+    return PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(text),
+                                 PyUnicode_GET_SIZE(text),
+                                 PyBytes_AS_STRING(self->errors), -1);
+}
+
+static PyObject *
+utf16_encode(PyTextIOWrapperObject *self, PyObject *text)
+{
+    PyObject *res;
+    res = PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(text),
+                                PyUnicode_GET_SIZE(text),
+                                PyBytes_AS_STRING(self->errors), 0);
+    if (res == NULL)
+        return NULL;
+    /* Next writes will skip the BOM and use native byte ordering */
+#if defined(WORDS_BIGENDIAN)
+    self->encodefunc = (encodefunc_t) utf16be_encode;
+#else
+    self->encodefunc = (encodefunc_t) utf16le_encode;
+#endif
+    return res;
+}
+
+
+static PyObject *
+utf8_encode(PyTextIOWrapperObject *self, PyObject *text)
+{
+    return PyUnicode_EncodeUTF8(PyUnicode_AS_UNICODE(text),
+                                PyUnicode_GET_SIZE(text),
+                                PyBytes_AS_STRING(self->errors));
+}
+
+static PyObject *
+latin1_encode(PyTextIOWrapperObject *self, PyObject *text)
+{
+    return PyUnicode_EncodeLatin1(PyUnicode_AS_UNICODE(text),
+                                  PyUnicode_GET_SIZE(text),
+                                  PyBytes_AS_STRING(self->errors));
+}
+
+/* Map normalized encoding names onto the specialized encoding funcs */
+
+typedef struct {
+    const char *name;
+    encodefunc_t encodefunc;
+} encodefuncentry;
+
+encodefuncentry encodefuncs[] = {
+    {"ascii",       (encodefunc_t) ascii_encode},
+    {"iso8859-1",   (encodefunc_t) latin1_encode},
+    {"utf-16-be",   (encodefunc_t) utf16be_encode},
+    {"utf-16-le",   (encodefunc_t) utf16le_encode},
+    {"utf-16",      (encodefunc_t) utf16_encode},
+    {"utf-8",       (encodefunc_t) utf8_encode},
+    {NULL, NULL}
+};
+
+
+static int
+TextIOWrapper_init(PyTextIOWrapperObject *self, PyObject *args, PyObject *kwds)
+{
+    char *kwlist[] = {"buffer", "encoding", "errors",
+                      "newline", "line_buffering",
+                      NULL};
+    PyObject *buffer;
+    char *encoding = NULL;
+    char *errors = NULL;
+    char *newline = NULL;
+    int line_buffering = 0;
+
+    PyObject *res;
+    int r;
+
+    self->ok = 0;
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|zzzi:fileio",
+                                     kwlist, &buffer, &encoding, &errors,
+                                     &newline, &line_buffering))
+        return -1;
+
+    if (newline && newline[0] != '\0'
+        && !(newline[0] == '\n' && newline[1] == '\0')
+        && !(newline[0] == '\r' && newline[1] == '\0')
+        && !(newline[0] == '\r' && newline[1] == '\n' && newline[2] == '\0')) {
+        PyErr_Format(PyExc_ValueError,
+                     "illegal newline value: %s", newline);
+        return -1;
+    }
+
+    Py_CLEAR(self->buffer);
+    Py_CLEAR(self->encoding);
+    Py_CLEAR(self->encoder);
+    Py_CLEAR(self->decoder);
+    Py_CLEAR(self->readnl);
+    Py_CLEAR(self->decoded_chars);
+    Py_CLEAR(self->pending_bytes);
+    Py_CLEAR(self->snapshot);
+    Py_CLEAR(self->errors);
+    self->decoded_chars_used = 0;
+    self->pending_bytes_count = 0;
+    self->encodefunc = NULL;
+
+    if (encoding == NULL) {
+        /* Try os.device_encoding(fileno) */
+        PyObject *fileno, *os;;
+        fileno = PyObject_CallMethod(buffer, "fileno", NULL);
+        /* Ignore any error */
+        /* XXX only AttributeError and UnsupportedOperation */
+        if (fileno == NULL)
+            PyErr_Clear();
+        else {
+            os = PyImport_ImportModule("os");
+            if (os == NULL) {
+                Py_DECREF(fileno);
+                goto error;
+            }
+            self->encoding = PyObject_CallMethod(os, "device_encoding",
+                                                 "N", fileno);
+            Py_DECREF(os);
+            if (self->encoding == NULL)
+                goto error;
+            else if (!PyUnicode_Check(self->encoding))
+                Py_CLEAR(self->encoding);
+        }
+    }
+    if (encoding == NULL && self->encoding == NULL) {
+        /* try locale.getpreferredencoding() */
+        PyObject *locale = PyImport_ImportModule("locale");
+        if (locale == NULL) {
+            PyErr_Clear();
+            self->encoding = PyUnicode_FromString("ascii");
+        }
+        else {
+            self->encoding = PyObject_CallMethod(
+                locale, "getpreferredencoding", NULL);
+            Py_DECREF(locale);
+            if (self->encoding == NULL)
+                goto error;
+            if (!PyUnicode_Check(self->encoding))
+                Py_CLEAR(self->encoding);
+        }
+    }
+    if (self->encoding != NULL)
+        encoding = _PyUnicode_AsString(self->encoding);
+    else if (encoding != NULL) {
+        self->encoding = PyUnicode_FromString(encoding);
+        if (self->encoding == NULL)
+            goto error;
+    }
+    else {
+        PyErr_SetString(PyExc_IOError,
+                        "could not determine default encoding");
+    }
+
+    if (errors == NULL)
+        errors = "strict";
+    self->errors = PyBytes_FromString(errors);
+    if (self->errors == NULL)
+        goto error;
+
+    self->chunk_size = 8192;
+    self->readuniversal = (newline == NULL || newline[0] == '\0');
+    self->line_buffering = line_buffering;
+    self->readtranslate = (newline == NULL);
+    if (newline)
+        self->readnl = PyUnicode_FromString(newline);
+    self->writetranslate = (newline == NULL || newline[0] != '\0');
+    if (!self->readuniversal && self->readnl) {
+        self->writenl = _PyUnicode_AsString(self->readnl);
+        if (!strcmp(self->writenl, "\n"))
+            self->writenl = NULL;
+    }
+#ifdef MS_WINDOWS
+    else
+        self->writenl = "\r\n";
+#endif
+
+    /* Build the decoder object */
+    res = PyObject_CallMethod(buffer, "readable", NULL);
+    if (res == NULL)
+        goto error;
+    r = PyObject_IsTrue(res);
+    Py_DECREF(res);
+    if (r == -1)
+        goto error;
+    if (r == 1) {
+        self->decoder = PyCodec_IncrementalDecoder(
+            encoding, errors);
+        if (self->decoder == NULL)
+            goto error;
+
+        if (self->readuniversal) {
+            PyObject *incrementalDecoder = PyObject_CallFunction(
+                (PyObject *)&PyIncrementalNewlineDecoder_Type,
+                "Oi", self->decoder, (int)self->readtranslate);
+            if (incrementalDecoder == NULL)
+                goto error;
+            Py_CLEAR(self->decoder);
+            self->decoder = incrementalDecoder;
+        }
+    }
+
+    /* Build the encoder object */
+    res = PyObject_CallMethod(buffer, "writable", NULL);
+    if (res == NULL)
+        goto error;
+    r = PyObject_IsTrue(res);
+    Py_DECREF(res);
+    if (r == -1)
+        goto error;
+    if (r == 1) {
+        PyObject *ci;
+        self->encoder = PyCodec_IncrementalEncoder(
+            encoding, errors);
+        if (self->encoder == NULL)
+            goto error;
+        /* Get the normalized named of the codec */
+        ci = _PyCodec_Lookup(encoding);
+        if (ci == NULL)
+            goto error;
+        res = PyObject_GetAttrString(ci, "name");
+        Py_DECREF(ci);
+        if (res == NULL)
+            PyErr_Clear();
+        else if (PyUnicode_Check(res)) {
+            encodefuncentry *e = encodefuncs;
+            while (e->name != NULL) {
+                if (!PyUnicode_CompareWithASCIIString(res, e->name)) {
+                    self->encodefunc = e->encodefunc;
+                    break;
+                }
+                e++;
+            }
+        }
+        Py_XDECREF(res);
+    }
+
+    self->buffer = buffer;
+    Py_INCREF(buffer);
+
+    res = PyObject_CallMethod(buffer, "seekable", NULL);
+    if (res == NULL)
+        goto error;
+    self->seekable = self->telling = PyObject_IsTrue(res);
+    Py_DECREF(res);
+
+    self->ok = 1;
+    return 0;
+
+  error:
+    return -1;
+}
+
+static void
+TextIOWrapper_dealloc(PyTextIOWrapperObject *self)
+{
+    PyObject *res;
+    /* XXX this is inelegant */
+    if (Py_TYPE(self)->tp_del == NULL && self->ok) {
+        PyObject *tp, *v, *tb;
+        PyErr_Fetch(&tp, &v, &tb);
+        /* We need to resurrect the object as calling close() can invoke
+           arbitrary code. */
+        ((PyObject *) self)->ob_refcnt++;
+        res = PyObject_CallMethodObjArgs((PyObject *) self, _PyIO_str_close,
+                                          NULL);
+        if (res == NULL) {
+            /* XXX dump exception on terminal?
+               But IOBase.__del__ prefers to remain silent... */
+            PyErr_Clear();
+        }
+        Py_XDECREF(res);
+        PyErr_Restore(tp, v, tb);
+        if (--((PyObject *) self)->ob_refcnt != 0)
+            return;
+    }
+    self->ok = 0;
+    Py_CLEAR(self->buffer);
+    Py_CLEAR(self->encoding);
+    Py_CLEAR(self->encoder);
+    Py_CLEAR(self->decoder);
+    Py_CLEAR(self->readnl);
+    Py_CLEAR(self->decoded_chars);
+    Py_CLEAR(self->snapshot);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs((PyObject *)self);
+    Py_CLEAR(self->dict);
+    Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+static PyObject *
+TextIOWrapper_closed_get(PyTextIOWrapperObject *self, void *context);
+
+/* This macro takes some shortcuts to make the common case faster. We could
+   specialize even more, by detecting that the underlying buffer is a 
+   BufferedObject. */
+#define CHECK_CLOSED(self) \
+    do { \
+        int r; \
+        PyObject *_res; \
+        if (Py_TYPE(self) == &PyTextIOWrapper_Type) { \
+            _res = TextIOWrapper_closed_get(self, NULL); \
+            if (_res == NULL) \
+                return NULL; \
+            r = PyObject_IsTrue(_res); \
+            Py_DECREF(_res); \
+            if (r < 0) \
+                return NULL; \
+            if (r > 0) { \
+                PyErr_SetString(PyExc_ValueError, \
+                                "I/O operation on closed file."); \
+                return NULL; \
+            } \
+        } \
+        else if (_PyIOBase_checkClosed((PyObject *)self, Py_True) == NULL) \
+            return NULL; \
+    } while (0)
+
+#define CHECK_INITIALIZED(self) \
+    if (self->ok <= 0) { \
+        PyErr_SetString(PyExc_ValueError, \
+            "I/O operation on uninitialized object"); \
+        return NULL; \
+    }
+
+#define CHECK_INITIALIZED_INT(self) \
+    if (self->ok <= 0) { \
+        PyErr_SetString(PyExc_ValueError, \
+            "I/O operation on uninitialized object"); \
+        return -1; \
+    }
+
+
+Py_LOCAL_INLINE(const Py_UNICODE *)
+findchar(const Py_UNICODE *s, Py_ssize_t size, Py_UNICODE ch)
+{
+    /* like wcschr, but doesn't stop at NULL characters */
+    while (size-- > 0) {
+        if (*s == ch)
+            return s;
+        s++;
+    }
+    return NULL;
+}
+
+/* Flush the internal write buffer. This doesn't explicitly flush the 
+   underlying buffered object, though. */
+static int
+_TextIOWrapper_writeflush(PyTextIOWrapperObject *self)
+{
+    PyObject *b, *ret;
+
+    if (self->pending_bytes == NULL)
+        return 0;
+    b = _PyBytes_Join(PyBytes_FromStringAndSize(NULL, 0), self->pending_bytes);
+    if (b == NULL)
+        return -1;
+    ret = PyObject_CallMethodObjArgs(self->buffer,
+                                     _PyIO_str_write, b, NULL);
+    Py_DECREF(b);
+    if (ret == NULL)
+        return -1;
+    Py_DECREF(ret);
+    Py_CLEAR(self->pending_bytes);
+    self->pending_bytes_count = 0;
+    return 0;
+}
+
+static PyObject *
+TextIOWrapper_write(PyTextIOWrapperObject *self, PyObject *args)
+{
+    PyObject *ret;
+    PyObject *text; /* owned reference */
+    PyObject *b;
+    Py_ssize_t textlen;
+    int haslf = 0;
+    int needflush = 0;
+
+    CHECK_INITIALIZED(self);
+
+    if (!PyArg_ParseTuple(args, "U:write", &text)) {
+        return NULL;
+    }
+
+    CHECK_CLOSED(self);
+
+    Py_INCREF(text);
+
+    textlen = PyUnicode_GetSize(text);
+
+    if ((self->writetranslate && self->writenl != NULL) || self->line_buffering)
+        if (findchar(PyUnicode_AS_UNICODE(text),
+                     PyUnicode_GET_SIZE(text), '\n'))
+            haslf = 1;
+
+    if (haslf && self->writetranslate && self->writenl != NULL) {
+        PyObject *newtext = PyObject_CallMethod(
+            text, "replace", "ss", "\n", self->writenl);
+        Py_DECREF(text);
+        if (newtext == NULL)
+            return NULL;
+        text = newtext;
+    }
+
+    if (self->line_buffering &&
+        (haslf ||
+         findchar(PyUnicode_AS_UNICODE(text),
+                  PyUnicode_GET_SIZE(text), '\r')))
+        needflush = 1;
+
+    /* XXX What if we were just reading? */
+    if (self->encodefunc != NULL)
+        b = (*self->encodefunc)((PyObject *) self, text);
+    else
+        b = PyObject_CallMethodObjArgs(self->encoder,
+                                       _PyIO_str_encode, text, NULL);
+    Py_DECREF(text);
+    if (b == NULL)
+        return NULL;
+
+    if (self->pending_bytes == NULL) {
+        self->pending_bytes = PyList_New(0);
+        if (self->pending_bytes == NULL) {
+            Py_DECREF(b);
+            return NULL;
+        }
+        self->pending_bytes_count = 0;
+    }
+    if (PyList_Append(self->pending_bytes, b) < 0) {
+        Py_DECREF(b);
+        return NULL;
+    }
+    self->pending_bytes_count += PyBytes_GET_SIZE(b);
+    Py_DECREF(b);
+    if (self->pending_bytes_count > self->chunk_size || needflush) {
+        if (_TextIOWrapper_writeflush(self) < 0)
+            return NULL;
+    }
+    
+    if (needflush) {
+        ret = PyObject_CallMethodObjArgs(self->buffer, _PyIO_str_flush, NULL);
+        if (ret == NULL)
+            return NULL;
+        Py_DECREF(ret);
+    }
+
+    Py_CLEAR(self->snapshot);
+
+    if (self->decoder) {
+        ret = PyObject_CallMethod(self->decoder, "reset", NULL);
+        if (ret == NULL)
+            return NULL;
+        Py_DECREF(ret);
+    }
+
+    return PyLong_FromSsize_t(textlen);
+}
+
+/* Steal a reference to chars and store it in the decoded_char buffer;
+ */
+static void
+TextIOWrapper_set_decoded_chars(PyTextIOWrapperObject *self, PyObject *chars)
+{
+    Py_CLEAR(self->decoded_chars);
+    self->decoded_chars = chars;
+    self->decoded_chars_used = 0;
+}
+
+static PyObject *
+TextIOWrapper_get_decoded_chars(PyTextIOWrapperObject *self, Py_ssize_t n)
+{
+    PyObject *chars;
+    Py_ssize_t avail;
+
+    if (self->decoded_chars == NULL)
+        return PyUnicode_FromStringAndSize(NULL, 0);
+
+    avail = (PyUnicode_GET_SIZE(self->decoded_chars)
+             - self->decoded_chars_used);
+
+    assert(avail >= 0);
+
+    if (n < 0 || n > avail)
+        n = avail;
+
+    if (self->decoded_chars_used > 0 || n < avail) {
+        chars = PyUnicode_FromUnicode(
+            PyUnicode_AS_UNICODE(self->decoded_chars)
+            + self->decoded_chars_used, n);
+        if (chars == NULL)
+            return NULL;
+    }
+    else {
+        chars = self->decoded_chars;
+        Py_INCREF(chars);
+    }
+
+    self->decoded_chars_used += n;
+    return chars;
+}
+
+/* Rewind the _decoded_chars buffer. */
+static int
+TextIOWrapper_rewind_decoded_chars(PyTextIOWrapperObject *self, Py_ssize_t n)
+{
+    if (self->decoded_chars_used < n) {
+        PyErr_SetString(PyExc_ValueError,
+                        "rewind decoded_chars out of bounds");
+        return -1;
+    }
+    self->decoded_chars_used -= n;
+    return self->decoded_chars_used;
+}
+
+static Py_ssize_t
+TextIOWrapper_decoded_chars_length(PyTextIOWrapperObject *self, Py_ssize_t n)
+{
+    if (self->decoded_chars == NULL)
+        return 0;
+    return PyUnicode_GetSize(self->decoded_chars) - self->decoded_chars_used;
+}
+
+
+/* Read and decode the next chunk of data from the BufferedReader.
+ */
+static int
+TextIOWrapper_read_chunk(PyTextIOWrapperObject *self)
+{
+    PyObject *dec_buffer = NULL;
+    PyObject *dec_flags = NULL;
+    PyObject *input_chunk = NULL;
+    PyObject *decoded_chars, *chunk_size;
+    int eof;
+
+    /* The return value is True unless EOF was reached.  The decoded string is
+     * placed in self._decoded_chars (replacing its previous value).  The
+     * entire input chunk is sent to the decoder, though some of it may remain
+     * buffered in the decoder, yet to be converted.
+     */
+
+    if (self->decoder == NULL) {
+        PyErr_SetString(PyExc_ValueError, "no decoder");
+        return -1;
+    }
+
+    if (self->telling) {
+        /* To prepare for tell(), we need to snapshot a point in the file
+         * where the decoder's input buffer is empty.
+         */
+
+        PyObject *state = PyObject_CallMethodObjArgs(self->decoder,
+                                                     _PyIO_str_getstate, NULL);
+        if (state == NULL)
+            return -1;
+        /* Given this, we know there was a valid snapshot point
+         * len(dec_buffer) bytes ago with decoder state (b'', dec_flags).
+         */
+        if (PyArg_Parse(state, "(OO)", &dec_buffer, &dec_flags) < 0) {
+            Py_DECREF(state);
+            return -1;
+        }
+        Py_INCREF(dec_buffer);
+        Py_INCREF(dec_flags);
+        Py_DECREF(state);
+    }
+
+    /* Read a chunk, decode it, and put the result in self._decoded_chars. */
+    chunk_size = PyLong_FromSsize_t(self->chunk_size);
+    if (chunk_size == NULL)
+        goto fail;
+    input_chunk = PyObject_CallMethodObjArgs(self->buffer,
+        _PyIO_str_read1, chunk_size, NULL);
+    Py_DECREF(chunk_size);
+    if (input_chunk == NULL)
+        goto fail;
+    assert(PyBytes_Check(input_chunk));
+
+    eof = (PyBytes_Size(input_chunk) == 0);
+
+    if (Py_TYPE(self->decoder) == &PyIncrementalNewlineDecoder_Type) {
+        decoded_chars = _IncrementalNewlineDecoder_decode(
+            (PyNewLineDecoderObject *) self->decoder, input_chunk, eof);
+    }
+    else {
+        decoded_chars = PyObject_CallMethodObjArgs(self->decoder,
+            _PyIO_str_decode, input_chunk, eof ? Py_True : Py_False, NULL);
+    }
+
+    /* TODO sanity check: isinstance(decoded_chars, unicode) */
+    if (decoded_chars == NULL)
+        goto fail;
+    TextIOWrapper_set_decoded_chars(self, decoded_chars);
+    if (PyUnicode_GET_SIZE(decoded_chars) > 0)
+        eof = 0;
+
+    if (self->telling) {
+        /* At the snapshot point, len(dec_buffer) bytes before the read, the
+         * next input to be decoded is dec_buffer + input_chunk.
+         */
+        PyObject *next_input = PyNumber_Add(dec_buffer, input_chunk);
+        if (next_input == NULL)
+            goto fail;
+        assert (PyBytes_Check(next_input));
+        Py_DECREF(dec_buffer);
+        Py_CLEAR(self->snapshot);
+        self->snapshot = Py_BuildValue("NN", dec_flags, next_input);
+    }
+    Py_DECREF(input_chunk);
+
+    return (eof == 0);
+
+  fail:
+    Py_XDECREF(dec_buffer);
+    Py_XDECREF(dec_flags);
+    Py_XDECREF(input_chunk);
+    return -1;
+}
+
+static PyObject *
+TextIOWrapper_read(PyTextIOWrapperObject *self, PyObject *args)
+{
+    Py_ssize_t n = -1;
+    PyObject *result = NULL, *chunks = NULL;
+
+    CHECK_INITIALIZED(self);
+
+    if (!PyArg_ParseTuple(args, "|n:read", &n))
+        return NULL;
+
+    CHECK_CLOSED(self);
+
+    if (_TextIOWrapper_writeflush(self) < 0)
+        return NULL;
+
+    if (n < 0) {
+        /* Read everything */
+        PyObject *bytes = PyObject_CallMethod(self->buffer, "read", NULL);
+        PyObject *decoded;
+        if (bytes == NULL)
+            goto fail;
+        decoded = PyObject_CallMethodObjArgs(self->decoder, _PyIO_str_decode,
+                                             bytes, Py_True, NULL);
+        Py_DECREF(bytes);
+        if (decoded == NULL)
+            goto fail;
+
+        result = TextIOWrapper_get_decoded_chars(self, -1);
+
+        if (result == NULL) {
+            Py_DECREF(decoded);
+            return NULL;
+        }
+
+        PyUnicode_AppendAndDel(&result, decoded);
+        if (result == NULL)
+            goto fail;
+
+        Py_CLEAR(self->snapshot);
+        return result;
+    }
+    else {
+        int res = 1;
+        Py_ssize_t remaining = n;
+
+        result = TextIOWrapper_get_decoded_chars(self, n);
+        if (result == NULL)
+            goto fail;
+        remaining -= PyUnicode_GET_SIZE(result);
+
+        /* Keep reading chunks until we have n characters to return */
+        while (remaining > 0) {
+            res = TextIOWrapper_read_chunk(self);
+            if (res < 0)
+                goto fail;
+            if (res == 0)  /* EOF */
+                break;
+            if (chunks == NULL) {
+                chunks = PyList_New(0);
+                if (chunks == NULL)
+                    goto fail;
+            }
+            if (PyList_Append(chunks, result) < 0)
+                goto fail;
+            Py_DECREF(result);
+            result = TextIOWrapper_get_decoded_chars(self, remaining);
+            if (result == NULL)
+                goto fail;
+            remaining -= PyUnicode_GET_SIZE(result);
+        }
+        if (chunks != NULL) {
+            if (result != NULL && PyList_Append(chunks, result) < 0)
+                goto fail;
+            Py_CLEAR(result);
+            result = PyUnicode_Join(PyUnicode_FromStringAndSize(NULL, 0),
+                                    chunks);
+            if (result == NULL)
+                goto fail;
+            Py_CLEAR(chunks);
+        }
+        return result;
+    }
+  fail:
+    Py_XDECREF(result);
+    Py_XDECREF(chunks);
+    return NULL;
+}
+
+
+/* NOTE: `end` must point to the real end of the Py_UNICODE storage,
+   that is to the NUL character. Otherwise the function will produce
+   incorrect results. */
+static Py_UNICODE *
+find_control_char(Py_UNICODE *start, Py_UNICODE *end, Py_UNICODE ch)
+{
+    Py_UNICODE *s = start;
+    for (;;) {
+        while (*s > ch)
+            s++;
+        if (*s == ch)
+            return s;
+        if (s == end)
+            return NULL;
+        s++;
+    }
+}
+
+/* Finds the first line ending between start and end.
+   If not found, returns -1 and sets (*consumed) to the number of characters
+   which can be safely put aside before another search.
+   If found, returns the index after the line ending and doesn't touch
+   (*consumed).
+   
+   NOTE: `end` must point to the real end of the Py_UNICODE storage,
+   that is to the NUL character. Otherwise the function will produce
+   incorrect results. */
+static Py_ssize_t
+find_line_ending(PyTextIOWrapperObject *self,
+                 Py_UNICODE *start, Py_UNICODE *end, Py_ssize_t *consumed)
+{
+    Py_ssize_t len = end - start;
+
+    if (self->readtranslate) {
+        /* Newlines are already translated, only search for \n */
+        Py_UNICODE *pos = find_control_char(start, end, '\n');
+        if (pos != NULL)
+            return pos - start + 1;
+        else {
+            *consumed = len;
+            return -1;
+        }
+    }
+    else if (self->readuniversal) {
+        /* Universal newline search. Find any of \r, \r\n, \n
+         * The decoder ensures that \r\n are not split in two pieces
+         */
+        Py_UNICODE *s = start;
+        for (;;) {
+            Py_UNICODE ch;
+            /* Fast path for non-control chars. The loop always ends
+               since the Py_UNICODE storage is NUL-terminated. */
+            while (*s > '\r')
+                s++;
+            if (s >= end) {
+                *consumed = len;
+                return -1;
+            }
+            ch = *s++;
+            if (ch == '\n')
+                return s - start;
+            if (ch == '\r') {
+                if (*s == '\n')
+                    return s - start + 1;
+                else
+                    return s - start;
+            }
+        }
+    }
+    else {
+        /* Non-universal mode. */
+        Py_ssize_t readnl_len = PyUnicode_GET_SIZE(self->readnl);
+        Py_UNICODE *nl = PyUnicode_AS_UNICODE(self->readnl);
+        if (readnl_len == 1) {
+            Py_UNICODE *pos = find_control_char(start, end, nl[0]);
+            if (pos != NULL)
+                return pos - start + 1;
+            *consumed = len;
+            return -1;
+        }
+        else {
+            Py_UNICODE *s = start;
+            Py_UNICODE *e = end - readnl_len + 1;
+            Py_UNICODE *pos;
+            if (e < s)
+                e = s;
+            while (s < e) {
+                Py_ssize_t i;
+                Py_UNICODE *pos = find_control_char(s, end, nl[0]);
+                if (pos == NULL || pos >= e)
+                    break;
+                for (i = 1; i < readnl_len; i++) {
+                    if (pos[i] != nl[i])
+                        break;
+                }
+                if (i == readnl_len)
+                    return pos - start + readnl_len;
+                s = pos + 1;
+            }
+            pos = find_control_char(e, end, nl[0]);
+            if (pos == NULL)
+                *consumed = len;
+            else
+                *consumed = pos - start;
+            return -1;
+        }
+    }
+}
+
+static PyObject *
+_TextIOWrapper_readline(PyTextIOWrapperObject *self, Py_ssize_t limit)
+{
+    PyObject *line = NULL, *chunks = NULL, *remaining = NULL;
+    Py_ssize_t start, endpos, chunked, offset_to_buffer;
+    int res;
+
+    CHECK_CLOSED(self);
+
+    if (_TextIOWrapper_writeflush(self) < 0)
+        return NULL;
+
+    chunked = 0;
+
+    while (1) {
+        Py_UNICODE *ptr;
+        Py_ssize_t line_len;
+        Py_ssize_t consumed = 0;
+
+        /* First, get some data if necessary */
+        res = 1;
+        while (!self->decoded_chars ||
+               !PyUnicode_GET_SIZE(self->decoded_chars)) {
+            res = TextIOWrapper_read_chunk(self);
+            if (res < 0)
+                goto error;
+            if (res == 0)
+                break;
+        }
+        if (res == 0) {
+            /* end of file */
+            TextIOWrapper_set_decoded_chars(self, NULL);
+            Py_CLEAR(self->snapshot);
+            start = endpos = offset_to_buffer = 0;
+            break;
+        }
+
+        if (remaining == NULL) {
+            line = self->decoded_chars;
+            start = self->decoded_chars_used;
+            offset_to_buffer = 0;
+            Py_INCREF(line);
+        }
+        else {
+            assert(self->decoded_chars_used == 0);
+            line = PyUnicode_Concat(remaining, self->decoded_chars);
+            start = 0;
+            offset_to_buffer = PyUnicode_GET_SIZE(remaining);
+            Py_CLEAR(remaining);
+            if (line == NULL)
+                goto error;
+        }
+
+        ptr = PyUnicode_AS_UNICODE(line);
+        line_len = PyUnicode_GET_SIZE(line);
+
+        endpos = find_line_ending(self, ptr + start, ptr + line_len, &consumed);
+        if (endpos >= 0) {
+            endpos += start;
+            if (limit >= 0 && (endpos - start) + chunked >= limit)
+                endpos = start + limit - chunked;
+            break;
+        }
+
+        /* We can put aside up to `endpos` */
+        endpos = consumed + start;
+        if (limit >= 0 && (endpos - start) + chunked >= limit) {
+            /* Didn't find line ending, but reached length limit */
+            endpos = start + limit - chunked;
+            break;
+        }
+
+        if (endpos > start) {
+            /* No line ending seen yet - put aside current data */
+            PyObject *s;
+            if (chunks == NULL) {
+                chunks = PyList_New(0);
+                if (chunks == NULL)
+                    goto error;
+            }
+            s = PyUnicode_FromUnicode(ptr + start, endpos - start);
+            if (s == NULL)
+                goto error;
+            if (PyList_Append(chunks, s) < 0) {
+                Py_DECREF(s);
+                goto error;
+            }
+            chunked += PyUnicode_GET_SIZE(s);
+            Py_DECREF(s);
+        }
+        /* There may be some remaining bytes we'll have to prepend to the
+           next chunk of data */
+        if (endpos < line_len) {
+            remaining = PyUnicode_FromUnicode(
+                    ptr + endpos, line_len - endpos);
+            if (remaining == NULL)
+                goto error;
+        }
+        Py_CLEAR(line);
+        /* We have consumed the buffer */
+        TextIOWrapper_set_decoded_chars(self, NULL);
+    }
+
+    if (line != NULL) {
+        /* Our line ends in the current buffer */
+        self->decoded_chars_used = endpos - offset_to_buffer;
+        if (start > 0 || endpos < PyUnicode_GET_SIZE(line)) {
+            if (start == 0 && Py_REFCNT(line) == 1) {
+                if (PyUnicode_Resize(&line, endpos) < 0)
+                    goto error;
+            }
+            else {
+                PyObject *s = PyUnicode_FromUnicode(
+                        PyUnicode_AS_UNICODE(line) + start, endpos - start);
+                Py_CLEAR(line);
+                if (s == NULL)
+                    goto error;
+                line = s;
+            }
+        }
+    }
+    if (remaining != NULL) {
+        if (chunks == NULL) {
+            chunks = PyList_New(0);
+            if (chunks == NULL)
+                goto error;
+        }
+        if (PyList_Append(chunks, remaining) < 0)
+            goto error;
+        Py_CLEAR(remaining);
+    }
+    if (chunks != NULL) {
+        if (line != NULL && PyList_Append(chunks, line) < 0)
+            goto error;
+        Py_CLEAR(line);
+        line = PyUnicode_Join(PyUnicode_FromStringAndSize(NULL, 0), chunks);
+        if (line == NULL)
+            goto error;
+        Py_DECREF(chunks);
+    }
+    if (line == NULL)
+        line = PyUnicode_FromStringAndSize(NULL, 0);
+
+    return line;
+
+  error:
+    Py_XDECREF(chunks);
+    Py_XDECREF(remaining);
+    Py_XDECREF(line);
+    return NULL;
+}
+
+static PyObject *
+TextIOWrapper_readline(PyTextIOWrapperObject *self, PyObject *args)
+{
+    Py_ssize_t limit = -1;
+
+    CHECK_INITIALIZED(self);
+    if (!PyArg_ParseTuple(args, "|n:readline", &limit)) {
+        return NULL;
+    }
+    return _TextIOWrapper_readline(self, limit);
+}
+
+/* Seek and Tell */
+
+typedef struct {
+    Py_off_t start_pos;
+    int dec_flags;
+    int bytes_to_feed;
+    int chars_to_skip;
+    char need_eof;
+} CookieStruct;
+
+/*
+   To speed up cookie packing/unpacking, we store the fields in a temporary
+   string and call _PyLong_FromByteArray() or _PyLong_AsByteArray (resp.).
+   The following macros define at which offsets in the intermediary byte
+   string the various CookieStruct fields will be stored.
+ */
+
+#define COOKIE_BUF_LEN      (sizeof(Py_off_t) + 3 * sizeof(int) + sizeof(char))
+
+#if defined(WORDS_BIGENDIAN)
+
+# define IS_LITTLE_ENDIAN   0
+
+/* We want the least significant byte of start_pos to also be the least
+   significant byte of the cookie, which means that in big-endian mode we
+   must copy the fields in reverse order. */
+
+# define OFF_START_POS      (sizeof(char) + 3 * sizeof(int))
+# define OFF_DEC_FLAGS      (sizeof(char) + 2 * sizeof(int))
+# define OFF_BYTES_TO_FEED  (sizeof(char) + sizeof(int))
+# define OFF_CHARS_TO_SKIP  (sizeof(char))
+# define OFF_NEED_EOF       0
+
+#else
+
+# define IS_LITTLE_ENDIAN   1
+
+/* Little-endian mode: the least significant byte of start_pos will
+   naturally end up the least significant byte of the cookie. */
+
+# define OFF_START_POS      0
+# define OFF_DEC_FLAGS      (sizeof(Py_off_t))
+# define OFF_BYTES_TO_FEED  (sizeof(Py_off_t) + sizeof(int))
+# define OFF_CHARS_TO_SKIP  (sizeof(Py_off_t) + 2 * sizeof(int))
+# define OFF_NEED_EOF       (sizeof(Py_off_t) + 3 * sizeof(int))
+
+#endif
+
+static int
+TextIOWrapper_parseCookie(CookieStruct *cookie, PyObject *cookieObj)
+{
+    unsigned char buffer[COOKIE_BUF_LEN];
+    PyLongObject *cookieLong = (PyLongObject *)PyNumber_Long(cookieObj);
+    if (cookieLong == NULL)
+        return -1;
+
+    if (_PyLong_AsByteArray(cookieLong, buffer, sizeof(buffer),
+                            IS_LITTLE_ENDIAN, 0) < 0) {
+        Py_DECREF(cookieLong);
+        return -1;
+    }
+    Py_DECREF(cookieLong);
+
+    cookie->start_pos     = * (Py_off_t *)(buffer + OFF_START_POS);
+    cookie->dec_flags     = * (int *)     (buffer + OFF_DEC_FLAGS);
+    cookie->bytes_to_feed = * (int *)     (buffer + OFF_BYTES_TO_FEED);
+    cookie->chars_to_skip = * (int *)     (buffer + OFF_CHARS_TO_SKIP);
+    cookie->need_eof      = * (char *)    (buffer + OFF_NEED_EOF);
+
+    return 0;
+}
+
+static PyObject *
+TextIOWrapper_buildCookie(CookieStruct *cookie)
+{
+    unsigned char buffer[COOKIE_BUF_LEN];
+
+    * (Py_off_t *)(buffer + OFF_START_POS)     = cookie->start_pos;
+    * (int *)     (buffer + OFF_DEC_FLAGS)     = cookie->dec_flags;
+    * (int *)     (buffer + OFF_BYTES_TO_FEED) = cookie->bytes_to_feed;
+    * (int *)     (buffer + OFF_CHARS_TO_SKIP) = cookie->chars_to_skip;
+    * (char *)    (buffer + OFF_NEED_EOF)      = cookie->need_eof;
+
+    return _PyLong_FromByteArray(buffer, sizeof(buffer), IS_LITTLE_ENDIAN, 0);
+}
+#undef IS_LITTLE_ENDIAN
+
+static int
+_TextIOWrapper_decoder_setstate(PyTextIOWrapperObject *self,
+                                CookieStruct *cookie)
+{
+    PyObject *res;
+    /* When seeking to the start of the stream, we call decoder.reset()
+       rather than decoder.getstate().
+       This is for a few decoders such as utf-16 for which the state value
+       at start is not (b"", 0) but e.g. (b"", 2) (meaning, in the case of
+       utf-16, that we are expecting a BOM).
+    */
+    if (cookie->start_pos == 0 && cookie->dec_flags == 0)
+        res = PyObject_CallMethod(self->decoder, "reset", NULL);
+    else
+        res = PyObject_CallMethod(self->decoder, "setstate",
+                                  "((yi))", "", cookie->dec_flags);
+    if (res == NULL)
+        return -1;
+    Py_DECREF(res);
+    return 0;
+}
+
+static PyObject *
+TextIOWrapper_seek(PyTextIOWrapperObject *self, PyObject *args)
+{
+    PyObject *cookieObj;
+    CookieStruct cookie;
+    int whence = 0;
+    static PyObject *zero = NULL;
+    PyObject *res;
+    int cmp;
+
+    CHECK_INITIALIZED(self);
+
+    if (zero == NULL) {
+        zero = PyLong_FromLong(0L);
+        if (zero == NULL)
+            return NULL;
+    }
+
+    if (!PyArg_ParseTuple(args, "O|i:seek", &cookieObj, &whence))
+        return NULL;
+    Py_INCREF(cookieObj);
+
+    CHECK_CLOSED(self);
+
+    if (!self->seekable) {
+        PyErr_SetString(PyExc_IOError,
+                        "underlying stream is not seekable");
+        goto fail;
+    }
+
+    if (whence == 1) {
+        /* seek relative to current position */
+        cmp = PyObject_RichCompareBool(cookieObj, zero, Py_EQ);
+        if (cmp < 0)
+            goto fail;
+
+        if (cmp == 0) {
+            PyErr_SetString(PyExc_IOError,
+                            "can't do nonzero cur-relative seeks");
+            goto fail;
+        }
+
+        /* Seeking to the current position should attempt to
+         * sync the underlying buffer with the current position.
+         */
+        Py_DECREF(cookieObj);
+        cookieObj = PyObject_CallMethod((PyObject *)self, "tell", NULL);
+        if (cookieObj == NULL)
+            goto fail;
+    }
+    else if (whence == 2) {
+        /* seek relative to end of file */
+
+        cmp = PyObject_RichCompareBool(cookieObj, zero, Py_EQ);
+        if (cmp < 0)
+            goto fail;
+
+        if (cmp == 0) {
+            PyErr_SetString(PyExc_IOError,
+                            "can't do nonzero end-relative seeks");
+            goto fail;
+        }
+
+        res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
+        if (res == NULL)
+            goto fail;
+        Py_DECREF(res);
+
+        TextIOWrapper_set_decoded_chars(self, NULL);
+        Py_CLEAR(self->snapshot);
+        if (self->decoder) {
+            res = PyObject_CallMethod(self->decoder, "reset", NULL);
+            if (res == NULL)
+                goto fail;
+            Py_DECREF(res);
+        }
+
+        res = PyObject_CallMethod(self->buffer, "seek", "ii", 0, 2);
+        return res;
+    }
+    else if (whence != 0) {
+        PyErr_Format(PyExc_ValueError,
+                     "invalid whence (%d, should be 0, 1 or 2)", whence);
+        goto fail;
+    }
+
+    cmp = PyObject_RichCompareBool(cookieObj, zero, Py_LT);
+    if (cmp < 0)
+        goto fail;
+
+    if (cmp == 1) {
+        PyErr_Format(PyExc_ValueError,
+                     "negative seek position %R", cookieObj);
+        goto fail;
+    }
+
+    res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
+    if (res == NULL)
+        goto fail;
+    Py_DECREF(res);
+
+    /* The strategy of seek() is to go back to the safe start point
+     * and replay the effect of read(chars_to_skip) from there.
+     */
+    if (TextIOWrapper_parseCookie(&cookie, cookieObj) < 0)
+        goto fail;
+
+    /* Seek back to the safe start point. */
+    res = PyObject_CallMethod(self->buffer, "seek",
+                              "L", (PY_LONG_LONG)cookie.start_pos);
+    if (res == NULL)
+        goto fail;
+    Py_DECREF(res);
+
+    TextIOWrapper_set_decoded_chars(self, NULL);
+    Py_CLEAR(self->snapshot);
+
+    /* Restore the decoder to its state from the safe start point. */
+    if (self->decoder) {
+        if (_TextIOWrapper_decoder_setstate(self, &cookie) < 0)
+            goto fail;
+        self->snapshot = Py_BuildValue("iy", cookie.dec_flags, "");
+        if (self->snapshot == NULL)
+            goto fail;
+    }
+
+    if (cookie.chars_to_skip) {
+        /* Just like _read_chunk, feed the decoder and save a snapshot. */
+        PyObject *input_chunk = PyObject_CallMethod(
+            self->buffer, "read", "i", cookie.bytes_to_feed);
+        PyObject *decoded;
+
+        if (input_chunk == NULL)
+            goto fail;
+
+        assert (PyBytes_Check(input_chunk));
+
+        self->snapshot = Py_BuildValue("iO", cookie.dec_flags, input_chunk);
+        if (self->snapshot == NULL) {
+            Py_DECREF(input_chunk);
+            goto fail;
+        }
+
+        decoded = PyObject_CallMethod(self->decoder, "decode",
+                                      "Ni", input_chunk, (int)cookie.need_eof);
+
+        if (decoded == NULL)
+            goto fail;
+
+        TextIOWrapper_set_decoded_chars(self, decoded);
+
+        /* Skip chars_to_skip of the decoded characters. */
+        if (PyUnicode_GetSize(self->decoded_chars) < cookie.chars_to_skip) {
+            PyErr_SetString(PyExc_IOError, "can't restore logical file position");
+            goto fail;
+        }
+        self->decoded_chars_used = cookie.chars_to_skip;
+    }
+
+    return cookieObj;
+  fail:
+    Py_XDECREF(cookieObj);
+    return NULL;
+
+}
+
+static PyObject *
+TextIOWrapper_tell(PyTextIOWrapperObject *self, PyObject *args)
+{
+    PyObject *res;
+    PyObject *posobj = NULL;
+    CookieStruct cookie = {0,0,0,0,0};
+    PyObject *next_input;
+    Py_ssize_t chars_to_skip, chars_decoded;
+    PyObject *saved_state = NULL;
+    char *input, *input_end;
+
+    CHECK_INITIALIZED(self);
+    CHECK_CLOSED(self);
+
+    if (!self->seekable) {
+        PyErr_SetString(PyExc_IOError,
+                        "underlying stream is not seekable");
+        goto fail;
+    }
+    if (!self->telling) {
+        PyErr_SetString(PyExc_IOError,
+                        "telling position disabled by next() call");
+        goto fail;
+    }
+
+    if (_TextIOWrapper_writeflush(self) < 0)
+        return NULL;
+    res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
+    if (res == NULL)
+        goto fail;
+    Py_DECREF(res);
+
+    posobj = PyObject_CallMethod(self->buffer, "tell", NULL);
+    if (posobj == NULL)
+        goto fail;
+
+    if (self->decoder == NULL || self->snapshot == NULL) {
+        assert (self->decoded_chars == NULL || PyUnicode_GetSize(self->decoded_chars) == 0);
+        return posobj;
+    }
+
+#if defined(HAVE_LARGEFILE_SUPPORT)
+    cookie.start_pos = PyLong_AsLongLong(posobj);
+#else
+    cookie.start_pos = PyLong_AsLong(posobj);
+#endif
+    if (PyErr_Occurred())
+        goto fail;
+
+    /* Skip backward to the snapshot point (see _read_chunk). */
+    if (!PyArg_Parse(self->snapshot, "(iO)", &cookie.dec_flags, &next_input))
+        goto fail;
+
+    assert (PyBytes_Check(next_input));
+
+    cookie.start_pos -= PyBytes_GET_SIZE(next_input);
+
+    /* How many decoded characters have been used up since the snapshot? */
+    if (self->decoded_chars_used == 0)  {
+        /* We haven't moved from the snapshot point. */
+        Py_DECREF(posobj);
+        return TextIOWrapper_buildCookie(&cookie);
+    }
+
+    chars_to_skip = self->decoded_chars_used;
+
+    /* Starting from the snapshot position, we will walk the decoder
+     * forward until it gives us enough decoded characters.
+     */
+    saved_state = PyObject_CallMethodObjArgs(self->decoder,
+                                             _PyIO_str_getstate, NULL);
+    if (saved_state == NULL)
+        goto fail;
+
+    /* Note our initial start point. */
+    if (_TextIOWrapper_decoder_setstate(self, &cookie) < 0)
+        goto fail;
+
+    /* Feed the decoder one byte at a time.  As we go, note the
+     * nearest "safe start point" before the current location
+     * (a point where the decoder has nothing buffered, so seek()
+     * can safely start from there and advance to this location).
+     */
+    chars_decoded = 0;
+    input = PyBytes_AS_STRING(next_input);
+    input_end = input + PyBytes_GET_SIZE(next_input);
+    while (input < input_end) {
+        PyObject *state;
+        char *dec_buffer;
+        int dec_buffer_len;
+        int dec_flags;
+
+        PyObject *decoded = PyObject_CallMethod(
+            self->decoder, "decode", "y#", input, 1);
+        if (decoded == NULL)
+            goto fail;
+        assert (PyUnicode_Check(decoded));
+        chars_decoded += PyUnicode_GET_SIZE(decoded);
+        Py_DECREF(decoded);
+
+        cookie.bytes_to_feed += 1;
+
+        state = PyObject_CallMethodObjArgs(self->decoder,
+                                           _PyIO_str_getstate, NULL);
+        if (state == NULL)
+            goto fail;
+        if (!PyArg_Parse(state, "(y#i)", &dec_buffer, &dec_buffer_len, &dec_flags)) {
+            Py_DECREF(state);
+            goto fail;
+        }
+        Py_DECREF(state);
+
+        if (dec_buffer_len == 0 && chars_decoded <= chars_to_skip) {
+            /* Decoder buffer is empty, so this is a safe start point. */
+            cookie.start_pos += cookie.bytes_to_feed;
+            chars_to_skip -= chars_decoded;
+            cookie.dec_flags = dec_flags;
+            cookie.bytes_to_feed = 0;
+            chars_decoded = 0;
+        }
+        if (chars_decoded >= chars_to_skip)
+            break;
+        input++;
+    }
+    if (input == input_end) {
+        /* We didn't get enough decoded data; signal EOF to get more. */
+        PyObject *decoded = PyObject_CallMethod(
+            self->decoder, "decode", "yi", "", /* final = */ 1);
+        if (decoded == NULL)
+            goto fail;
+        assert (PyUnicode_Check(decoded));
+        chars_decoded += PyUnicode_GET_SIZE(decoded);
+        cookie.need_eof = 1;
+
+        if (chars_decoded < chars_to_skip) {
+            PyErr_SetString(PyExc_IOError,
+                            "can't reconstruct logical file position");
+            goto fail;
+        }
+    }
+
+    /* finally */
+    Py_XDECREF(posobj);
+    res = PyObject_CallMethod(self->decoder, "setstate", "(O)", saved_state);
+    Py_DECREF(saved_state);
+    if (res == NULL)
+        return NULL;
+    Py_DECREF(res);
+
+    /* The returned cookie corresponds to the last safe start point. */
+    cookie.chars_to_skip = Py_SAFE_DOWNCAST(chars_to_skip, Py_ssize_t, int);
+    return TextIOWrapper_buildCookie(&cookie);
+
+  fail:
+    Py_XDECREF(posobj);
+    if (saved_state) {
+        PyObject *type, *value, *traceback;
+        PyErr_Fetch(&type, &value, &traceback);
+
+        res = PyObject_CallMethod(self->decoder, "setstate", "(O)", saved_state);
+        Py_DECREF(saved_state);
+        if (res == NULL)
+            return NULL;
+        Py_DECREF(res);
+
+        PyErr_Restore(type, value, traceback);
+    }
+    return NULL;
+}
+
+/* Inquiries */
+
+static PyObject *
+TextIOWrapper_fileno(PyTextIOWrapperObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_CallMethod(self->buffer, "fileno", NULL);
+}
+
+static PyObject *
+TextIOWrapper_seekable(PyTextIOWrapperObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_CallMethod(self->buffer, "seekable", NULL);
+}
+
+static PyObject *
+TextIOWrapper_readable(PyTextIOWrapperObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_CallMethod(self->buffer, "readable", NULL);
+}
+
+static PyObject *
+TextIOWrapper_writable(PyTextIOWrapperObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_CallMethod(self->buffer, "writable", NULL);
+}
+
+static PyObject *
+TextIOWrapper_isatty(PyTextIOWrapperObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_CallMethod(self->buffer, "isatty", NULL);
+}
+
+static PyObject *
+TextIOWrapper_flush(PyTextIOWrapperObject *self, PyObject *args)
+{
+    CHECK_INITIALIZED(self);
+    CHECK_CLOSED(self);
+    self->telling = self->seekable;
+    if (_TextIOWrapper_writeflush(self) < 0)
+        return NULL;
+    return PyObject_CallMethod(self->buffer, "flush", NULL);
+}
+
+static PyObject *
+TextIOWrapper_close(PyTextIOWrapperObject *self, PyObject *args)
+{
+    PyObject *res;
+    CHECK_INITIALIZED(self);
+    res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
+    if (res == NULL) {
+        /* If flush() fails, just give up */
+        PyErr_Clear();
+    }
+    else
+        Py_DECREF(res);
+
+    return PyObject_CallMethod(self->buffer, "close", NULL);
+}
+
+static PyObject *
+TextIOWrapper_iternext(PyTextIOWrapperObject *self)
+{
+    PyObject *line;
+
+    CHECK_INITIALIZED(self);
+
+    self->telling = 0;
+    if (Py_TYPE(self) == &PyTextIOWrapper_Type) {
+        /* Skip method call overhead for speed */
+        line = _TextIOWrapper_readline(self, -1);
+    }
+    else {
+        line = PyObject_CallMethodObjArgs((PyObject *)self,
+                                           _PyIO_str_readline, NULL);
+        /* TODO: check return type */
+    }
+
+    if (line == NULL)
+        return NULL;
+
+    assert (PyUnicode_Check(line));
+
+    if (PyUnicode_GET_SIZE(line) == 0) {
+        /* Reached EOF or would have blocked */
+        Py_DECREF(line);
+        Py_CLEAR(self->snapshot);
+        self->telling = self->seekable;
+        return NULL;
+    }
+
+    return line;
+}
+
+static PyObject *
+TextIOWrapper_name_get(PyTextIOWrapperObject *self, void *context)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_GetAttrString(self->buffer, "name");
+}
+
+static PyObject *
+TextIOWrapper_closed_get(PyTextIOWrapperObject *self, void *context)
+{
+    CHECK_INITIALIZED(self);
+    return PyObject_GetAttr(self->buffer, _PyIO_str_closed);
+}
+
+static PyObject *
+TextIOWrapper_newlines_get(PyTextIOWrapperObject *self, void *context)
+{
+    PyObject *res;
+    CHECK_INITIALIZED(self);
+    if (self->decoder == NULL)
+        Py_RETURN_NONE;
+    res = PyObject_GetAttr(self->decoder, _PyIO_str_newlines);
+    if (res == NULL) {
+        PyErr_Clear();
+        Py_RETURN_NONE;
+    }
+    return res;
+}
+
+static PyObject *
+TextIOWrapper_chunk_size_get(PyTextIOWrapperObject *self, void *context)
+{
+    CHECK_INITIALIZED(self);
+    return PyLong_FromSsize_t(self->chunk_size);
+}
+
+static int
+TextIOWrapper_chunk_size_set(PyTextIOWrapperObject *self,
+                             PyObject *arg, void *context)
+{
+    Py_ssize_t n;
+    CHECK_INITIALIZED_INT(self);
+    n = PyNumber_AsSsize_t(arg, PyExc_TypeError);
+    if (n == -1 && PyErr_Occurred())
+        return -1;
+    if (n <= 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "a strictly positive integer is required");
+        return -1;
+    }
+    self->chunk_size = n;
+    return 0;
+}
+
+static PyMethodDef TextIOWrapper_methods[] = {
+    {"write", (PyCFunction)TextIOWrapper_write, METH_VARARGS},
+    {"read", (PyCFunction)TextIOWrapper_read, METH_VARARGS},
+    {"readline", (PyCFunction)TextIOWrapper_readline, METH_VARARGS},
+    {"flush", (PyCFunction)TextIOWrapper_flush, METH_NOARGS},
+    {"close", (PyCFunction)TextIOWrapper_close, METH_NOARGS},
+
+    {"fileno", (PyCFunction)TextIOWrapper_fileno, METH_NOARGS},
+    {"seekable", (PyCFunction)TextIOWrapper_seekable, METH_NOARGS},
+    {"readable", (PyCFunction)TextIOWrapper_readable, METH_NOARGS},
+    {"writable", (PyCFunction)TextIOWrapper_writable, METH_NOARGS},
+    {"isatty", (PyCFunction)TextIOWrapper_isatty, METH_NOARGS},
+
+    {"seek", (PyCFunction)TextIOWrapper_seek, METH_VARARGS},
+    {"tell", (PyCFunction)TextIOWrapper_tell, METH_NOARGS},
+/*    {"truncate", (PyCFunction)TextIOWrapper_truncate, METH_VARARGS},
+    {"readinto", (PyCFunction)TextIOWrapper_readinto, METH_VARARGS},
+    {"peek", (PyCFunction)TextIOWrapper_peek, METH_VARARGS},
+    {"read1", (PyCFunction)TextIOWrapper_read1, METH_VARARGS},
+*/
+    {NULL, NULL}
+};
+
+static PyMemberDef TextIOWrapper_members[] = {
+    {"encoding", T_OBJECT, offsetof(PyTextIOWrapperObject, encoding), READONLY},
+    {"buffer", T_OBJECT, offsetof(PyTextIOWrapperObject, buffer), READONLY},
+    {NULL}
+};
+
+static PyGetSetDef TextIOWrapper_getset[] = {
+    {"name", (getter)TextIOWrapper_name_get, NULL, NULL},
+    {"closed", (getter)TextIOWrapper_closed_get, NULL, NULL},
+/*    {"mode", (getter)TextIOWrapper_mode_get, NULL, NULL},
+*/
+    {"newlines", (getter)TextIOWrapper_newlines_get, NULL, NULL},
+    {"_CHUNK_SIZE", (getter)TextIOWrapper_chunk_size_get,
+                    (setter)TextIOWrapper_chunk_size_set, NULL},
+    {0}
+};
+
+PyTypeObject PyTextIOWrapper_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "TextIOWrapper",            /*tp_name*/
+    sizeof(PyTextIOWrapperObject), /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    (destructor)TextIOWrapper_dealloc, /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+    TextIOWrapper_doc,          /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    offsetof(PyTextIOWrapperObject, weakreflist), /*tp_weaklistoffset*/
+    0,                          /* tp_iter */
+    (iternextfunc)TextIOWrapper_iternext, /* tp_iternext */
+    TextIOWrapper_methods,      /* tp_methods */
+    TextIOWrapper_members,      /* tp_members */
+    TextIOWrapper_getset,       /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    offsetof(PyTextIOWrapperObject, dict), /*tp_dictoffset*/
+    (initproc)TextIOWrapper_init, /* tp_init */
+    0,                          /* tp_alloc */
+    PyType_GenericNew,          /* tp_new */
+};

Added: python/branches/io-c/Modules/io.c
==============================================================================
--- (empty file)
+++ python/branches/io-c/Modules/io.c	Sun Jan 18 00:13:48 2009
@@ -0,0 +1,727 @@
+#include "Python.h"
+#include "structmember.h"
+#include "_iomodule.h"
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif /* HAVE_SYS_TYPES_H */
+
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif /* HAVE_SYS_STAT_H */
+
+PyObject *PyIOExc_UnsupportedOperation;
+
+/* Various interned strings */
+
+PyObject *_PyIO_str_close;
+PyObject *_PyIO_str_closed;
+PyObject *_PyIO_str_decode;
+PyObject *_PyIO_str_encode;
+PyObject *_PyIO_str_fileno;
+PyObject *_PyIO_str_flush;
+PyObject *_PyIO_str_getstate;
+PyObject *_PyIO_str_isatty;
+PyObject *_PyIO_str_newlines;
+PyObject *_PyIO_str_read;
+PyObject *_PyIO_str_read1;
+PyObject *_PyIO_str_readable;
+PyObject *_PyIO_str_readinto;
+PyObject *_PyIO_str_readline;
+PyObject *_PyIO_str_seek;
+PyObject *_PyIO_str_seekable;
+PyObject *_PyIO_str_tell;
+PyObject *_PyIO_str_truncate;
+PyObject *_PyIO_str_writable;
+PyObject *_PyIO_str_write;
+
+
+PyDoc_STRVAR(module_doc,
+"The io module provides the Python interfaces to stream handling. The\n"
+"builtin open function is defined in this module.\n"
+"\n"
+"At the top of the I/O hierarchy is the abstract base class IOBase. It\n"
+"defines the basic interface to a stream. Note, however, that there is no\n"
+"seperation between reading and writing to streams; implementations are\n"
+"allowed to throw an IOError if they do not support a given operation.\n"
+"\n"
+"Extending IOBase is RawIOBase which deals simply with the reading and\n"
+"writing of raw bytes to a stream. FileIO subc lasses RawIOBase to provide\n"
+"an interface to OS files.\n"
+"\n"
+"BufferedIOBase deals with buffering on a raw byte stream (RawIOBase). Its\n"
+"subclasses, BufferedWriter, BufferedReader, and BufferedRWPair buffer\n"
+"streams that are readable, writable, and both respectively.\n"
+"BufferedRandom provides a buffered interface to random access\n"
+"streams. BytesIO is a simple stream of in-memory bytes.\n"
+"\n"
+"Another IOBase subclass, TextIOBase, deals with the encoding and decoding\n"
+"of streams into text. TextIOWrapper, which extends it, is a buffered text\n"
+"interface to a buffered raw stream (`BufferedIOBase`). Finally, StringIO\n"
+"is a in-memory stream for text.\n"
+"\n"
+"Argument names are not part of the specification, and only the arguments\n"
+"of open() are intended to be used as keyword arguments.\n"
+"\n"
+"data:\n"
+"\n"
+"DEFAULT_BUFFER_SIZE\n"
+"\n"
+"   An int containing the default buffer size used by the module's buffered\n"
+"   I/O classes. open() uses the file's blksize (as obtained by os.stat) if\n"
+"   possible.\n"
+    );
+
+
+/*
+ * BlockingIOError extends IOError
+ */
+
+static int
+BlockingIOError_init(PyBlockingIOErrorObject *self, PyObject *args,
+                     PyObject *kwds)
+{
+    PyObject *myerrno = NULL, *strerror = NULL, *written;
+    PyObject *baseargs = NULL;
+
+    assert(PyTuple_Check(args));
+
+    if (PyTuple_GET_SIZE(args) <= 1 || PyTuple_GET_SIZE(args) > 3)
+        return 0;
+
+    baseargs = PyTuple_GetSlice(args, 0, 2);
+    if (baseargs == NULL)
+        return -1;
+
+    if (((PyTypeObject *)PyExc_IOError)->tp_init(
+                (PyObject *)self, baseargs, kwds) == -1) {
+        Py_DECREF(baseargs);
+        return -1;
+    }
+
+    Py_DECREF(baseargs);
+
+    if (!PyArg_UnpackTuple(args, "BlockingIOError", 2, 3,
+                           &myerrno, &strerror, &written)) {
+        return -1;
+    }
+
+    Py_INCREF(myerrno);
+    self->myerrno = myerrno;
+
+    Py_INCREF(strerror);
+    self->strerror = strerror;
+
+    self->written = PyNumber_AsSsize_t(written, PyExc_ValueError);
+    if(self->written == -1 && PyErr_Occurred())
+        return -1;
+
+    return 0;
+}
+
+static PyMemberDef BlockingIOError_members[] = {
+    {"characters_written", T_PYSSIZET, offsetof(PyBlockingIOErrorObject, written), 0},
+    {NULL}  /* Sentinel */
+};
+
+
+static PyTypeObject _PyExc_BlockingIOError = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "BlockingIOError", /*tp_name*/
+    sizeof(PyBlockingIOErrorObject), /*tp_basicsize*/
+    0,                          /*tp_itemsize*/
+    0,                          /*tp_dealloc*/
+    0,                          /*tp_print*/
+    0,                          /*tp_getattr*/
+    0,                          /*tp_setattr*/
+    0,                          /*tp_compare */
+    0,                          /*tp_repr*/
+    0,                          /*tp_as_number*/
+    0,                          /*tp_as_sequence*/
+    0,                          /*tp_as_mapping*/
+    0,                          /*tp_hash */
+    0,                          /*tp_call*/
+    0,                          /*tp_str*/
+    0,                          /*tp_getattro*/
+    0,                          /*tp_setattro*/
+    0,                          /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,  /*tp_flags*/
+    PyDoc_STR("Exception raised when I/O would block on a non-blocking I/O stream"), /* tp_doc */
+    0,                          /* tp_traverse */
+    0,                          /* tp_clear */
+    0,                          /* tp_richcompare */
+    0,                          /* tp_weaklistoffset */
+    0,                          /* tp_iter */
+    0,                          /* tp_iternext */
+    0,                          /* tp_methods */
+    BlockingIOError_members,    /* tp_members */
+    0,                          /* tp_getset */
+    0,                          /* tp_base */
+    0,                          /* tp_dict */
+    0,                          /* tp_descr_get */
+    0,                          /* tp_descr_set */
+    0,                          /* tp_dictoffset */
+    (initproc)BlockingIOError_init, /* tp_init */
+    0,                          /* tp_alloc */
+    0,                          /* tp_new */
+};
+PyObject *PyExc_BlockingIOError = (PyObject *)&_PyExc_BlockingIOError;
+
+
+/*
+ * The main open() function
+ */
+PyDoc_STRVAR(open_doc,
+"Open file and return a stream.  Raise IOError upon failure.\n"
+"\n"
+"file is either a text or byte string giving the name (and the path\n"
+"if the file isn't in the current working directory) of the file to\n"
+"be opened or an integer file descriptor of the file to be\n"
+"wrapped. (If a file descriptor is given, it is closed when the\n"
+"returned I/O object is closed, unless closefd is set to False.)\n"
+"\n"
+"mode is an optional string that specifies the mode in which the file\n"
+"is opened. It defaults to 'r' which means open for reading in text\n"
+"mode.  Other common values are 'w' for writing (truncating the file if\n"
+"it already exists), and 'a' for appending (which on some Unix systems,\n"
+"means that all writes append to the end of the file regardless of the\n"
+"current seek position). In text mode, if encoding is not specified the\n"
+"encoding used is platform dependent. (For reading and writing raw\n"
+"bytes use binary mode and leave encoding unspecified.) The available\n"
+"modes are:\n"
+"\n"
+"========= ===============================================================\n"
+"Character Meaning\n"
+"--------- ---------------------------------------------------------------\n"
+"'r'       open for reading (default)\n"
+"'w'       open for writing, truncating the file first\n"
+"'a'       open for writing, appending to the end of the file if it exists\n"
+"'b'       binary mode\n"
+"'t'       text mode (default)\n"
+"'+'       open a disk file for updating (reading and writing)\n"
+"'U'       universal newline mode (for backwards compatibility; unneeded\n"
+"          for new code)\n"
+"========= ===============================================================\n"
+"\n"
+"The default mode is 'rt' (open for reading text). For binary random\n"
+"access, the mode 'w+b' opens and truncates the file to 0 bytes, while\n"
+"'r+b' opens the file without truncation.\n"
+"\n"
+"Python distinguishes between files opened in binary and text modes,\n"
+"even when the underlying operating system doesn't. Files opened in\n"
+"binary mode (appending 'b' to the mode argument) return contents as\n"
+"bytes objects without any decoding. In text mode (the default, or when\n"
+"'t' is appended to the mode argument), the contents of the file are\n"
+"returned as strings, the bytes having been first decoded using a\n"
+"platform-dependent encoding or using the specified encoding if given.\n"
+"\n"
+"buffering is an optional integer used to set the buffering policy. By\n"
+"default full buffering is on. Pass 0 to switch buffering off (only\n"
+"allowed in binary mode), 1 to set line buffering, and an integer > 1\n"
+"for full buffering.\n"
+"\n"
+"encoding is the name of the encoding used to decode or encode the\n"
+"file. This should only be used in text mode. The default encoding is\n"
+"platform dependent, but any encoding supported by Python can be\n"
+"passed.  See the codecs module for the list of supported encodings.\n"
+"\n"
+"errors is an optional string that specifies how encoding errors are to\n"
+"be handled---this argument should not be used in binary mode. Pass\n"
+"'strict' to raise a ValueError exception if there is an encoding error\n"
+"(the default of None has the same effect), or pass 'ignore' to ignore\n"
+"errors. (Note that ignoring encoding errors can lead to data loss.)\n"
+"See the documentation for codecs.register for a list of the permitted\n"
+"encoding error strings.\n"
+"\n"
+"newline controls how universal newlines works (it only applies to text\n"
+"mode). It can be None, '', '\\n', '\\r', and '\\r\\n'.  It works as\n"
+"follows:\n"
+"\n"
+"* On input, if newline is None, universal newlines mode is\n"
+"  enabled. Lines in the input can end in '\\n', '\\r', or '\\r\\n', and\n"
+"  these are translated into '\\n' before being returned to the\n"
+"  caller. If it is '', universal newline mode is enabled, but line\n"
+"  endings are returned to the caller untranslated. If it has any of\n"
+"  the other legal values, input lines are only terminated by the given\n"
+"  string, and the line ending is returned to the caller untranslated.\n"
+"\n"
+"* On output, if newline is None, any '\\n' characters written are\n"
+"  translated to the system default line separator, os.linesep. If\n"
+"  newline is '', no translation takes place. If newline is any of the\n"
+"  other legal values, any '\\n' characters written are translated to\n"
+"  the given string.\n"
+"\n"
+"If closefd is False, the underlying file descriptor will be kept open\n"
+"when the file is closed. This does not work when a file name is given\n"
+"and must be True in that case.\n"
+"\n"
+"open() returns a file object whose type depends on the mode, and\n"
+"through which the standard file operations such as reading and writing\n"
+"are performed. When open() is used to open a file in a text mode ('w',\n"
+"'r', 'wt', 'rt', etc.), it returns a TextIOWrapper. When used to open\n"
+"a file in a binary mode, the returned class varies: in read binary\n"
+"mode, it returns a BufferedReader; in write binary and append binary\n"
+"modes, it returns a BufferedWriter, and in read/write mode, it returns\n"
+"a BufferedRandom.\n"
+"\n"
+"It is also possible to use a string or bytearray as a file for both\n"
+"reading and writing. For strings StringIO can be used like a file\n"
+"opened in a text mode, and for bytes a BytesIO can be used like a file\n"
+"opened in a binary mode.\n"
+    );
+
+static PyObject *
+io_open(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    char *kwlist[] = {"file", "mode", "buffering",
+                      "encoding", "errors", "newline",
+                      "closefd", NULL};
+    PyObject *file;
+    char *mode = "r";
+    int buffering = -1, closefd = 1;
+    char *encoding = NULL, *errors = NULL, *newline = NULL;
+    unsigned i;
+
+    int reading = 0, writing = 0, appending = 0, updating = 0;
+    int text = 0, binary = 0, universal = 0;
+
+    char rawmode[5], *m;
+    int line_buffering, isatty;
+
+    PyObject *raw, *modeobj = NULL, *buffer = NULL, *wrapper = NULL;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|sizzzi:open", kwlist,
+                                     &file, &mode, &buffering,
+                                     &encoding, &errors, &newline,
+                                     &closefd)) {
+        return NULL;
+    }
+
+    if (!PyUnicode_Check(file) &&
+	!PyBytes_Check(file) &&
+	!PyNumber_Check(file)) {
+        PyErr_Format(PyExc_TypeError, "invalid file: %R", file);
+        return NULL;
+    }
+
+    /* Decode mode */
+    for (i = 0; i < strlen(mode); i++) {
+        char c = mode[i];
+
+        switch (c) {
+        case 'r':
+            reading = 1;
+            break;
+        case 'w':
+            writing = 1;
+            break;
+        case 'a':
+            appending = 1;
+            break;
+        case '+':
+            updating = 1;
+            break;
+        case 't':
+            text = 1;
+            break;
+        case 'b':
+            binary = 1;
+            break;
+        case 'U':
+            universal = 1;
+            reading = 1;
+            break;
+        default:
+            goto invalid_mode;
+        }
+
+        /* c must not be duplicated */
+        if (strchr(mode+i+1, c)) {
+          invalid_mode:
+            PyErr_Format(PyExc_ValueError, "invalid mode: '%s'", mode);
+            return NULL;
+        }
+
+    }
+
+    m = rawmode;
+    if (reading)   *(m++) = 'r';
+    if (writing)   *(m++) = 'w';
+    if (appending) *(m++) = 'a';
+    if (updating)  *(m++) = '+';
+    *m = '\0';
+
+    /* Parameters validation */
+    if (universal) {
+        if (writing || appending) {
+            PyErr_SetString(PyExc_ValueError,
+                            "can't use U and writing mode at once");
+            return NULL;
+        }
+        reading = 1;
+    }
+
+    if (text && binary) {
+        PyErr_SetString(PyExc_ValueError,
+                        "can't have text and binary mode at once");
+        return NULL;
+    }
+
+    if (reading + writing + appending > 1) {
+        PyErr_SetString(PyExc_ValueError,
+                        "must have exactly one of read/write/append mode");
+        return NULL;
+    }
+
+    if (binary && encoding != NULL) {
+        PyErr_SetString(PyExc_ValueError,
+                        "binary mode doesn't take an encoding argument");
+        return NULL;
+    }
+
+    if (binary && errors != NULL) {
+        PyErr_SetString(PyExc_ValueError,
+                        "binary mode doesn't take an errors argument");
+        return NULL;
+    }
+
+    if (binary && newline != NULL) {
+        PyErr_SetString(PyExc_ValueError,
+                        "binary mode doesn't take a newline argument");
+        return NULL;
+    }
+
+    /* Create the Raw file stream */
+    raw = PyObject_CallFunction((PyObject *)&PyFileIO_Type,
+				"Osi", file, rawmode, closefd);
+    if (raw == NULL)
+        return NULL;
+
+    modeobj = PyUnicode_FromString(mode);
+    if (modeobj == NULL)
+        goto error;
+
+    /* buffering */
+    {
+        PyObject *res = PyObject_CallMethod(raw, "isatty", NULL);
+        if (res == NULL)
+            goto error;
+        isatty = PyLong_AsLong(res);
+        Py_DECREF(res);
+        if (isatty == -1 && PyErr_Occurred())
+            goto error;
+    }
+
+    if (buffering == 1 || (buffering < 0 && isatty)) {
+        buffering = -1;
+        line_buffering = 1;
+    }
+    else
+        line_buffering = 0;
+
+    if (buffering < 0) {
+        buffering = DEFAULT_BUFFER_SIZE;
+#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
+        {
+            struct stat st;
+            long fileno;
+            PyObject *res = PyObject_CallMethod(raw, "fileno", NULL);
+            if (res == NULL)
+                goto error;
+
+            fileno = PyLong_AsLong(res);
+            Py_DECREF(res);
+            if (fileno == -1 && PyErr_Occurred())
+                goto error;
+
+            if (fstat(fileno, &st) >= 0)
+                buffering = st.st_blksize;
+        }
+#endif
+    }
+    if (buffering < 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "invalid buffering size");
+        goto error;
+    }
+
+    /* if not buffering, returns the raw file object */
+    if (buffering == 0) {
+        if (!binary) {
+            PyErr_SetString(PyExc_ValueError,
+                            "can't have unbuffered text I/O");
+            goto error;
+        }
+
+        Py_DECREF(modeobj);
+        return raw;
+    }
+
+    /* wraps into a buffered file */
+    {
+        PyObject *Buffered_class;
+
+        if (updating)
+            Buffered_class = (PyObject *)&PyBufferedRandom_Type;
+        else if (writing || appending)
+            Buffered_class = (PyObject *)&PyBufferedWriter_Type;
+        else if (reading)
+            Buffered_class = (PyObject *)&PyBufferedReader_Type;
+        else {
+            PyErr_Format(PyExc_ValueError,
+                         "unknown mode: '%s'", mode);
+            goto error;
+        }
+
+        buffer = PyObject_CallFunction(Buffered_class, "Oi", raw, buffering);
+    }
+    Py_CLEAR(raw);
+    if (buffer == NULL)
+        goto error;
+
+
+    /* if binary, returns the buffered file */
+    if (binary) {
+        Py_DECREF(modeobj);
+        return buffer;
+    }
+
+    /* wraps into a TextIOWrapper */
+    wrapper = PyObject_CallFunction((PyObject *)&PyTextIOWrapper_Type,
+				    "Osssi",
+				    buffer,
+				    encoding, errors, newline,
+				    line_buffering);
+    Py_CLEAR(buffer);
+    if (wrapper == NULL)
+        goto error;
+
+    if (PyObject_SetAttrString(wrapper, "mode", modeobj) < 0)
+        goto error;
+    Py_DECREF(modeobj);
+    return wrapper;
+
+  error:
+    Py_XDECREF(raw);
+    Py_XDECREF(modeobj);
+    Py_XDECREF(buffer);
+    Py_XDECREF(wrapper);
+    return NULL;
+}
+
+/*
+ * Private helpers for the io module.
+ */
+
+Py_off_t
+PyNumber_AsOff_t(PyObject *item, PyObject *err)
+{
+    Py_off_t result;
+    PyObject *runerr;
+    PyObject *value = PyNumber_Index(item);
+    if (value == NULL)
+        return -1;
+
+    /* We're done if PyLong_AsSsize_t() returns without error. */
+    result = PyLong_AsOff_t(value);
+    if (result != -1 || !(runerr = PyErr_Occurred()))
+        goto finish;
+
+    /* Error handling code -- only manage OverflowError differently */
+    if (!PyErr_GivenExceptionMatches(runerr, PyExc_OverflowError))
+        goto finish;
+
+    PyErr_Clear();
+    /* If no error-handling desired then the default clipping
+       is sufficient.
+     */
+    if (!err) {
+        assert(PyLong_Check(value));
+        /* Whether or not it is less than or equal to
+           zero is determined by the sign of ob_size
+        */
+        if (_PyLong_Sign(value) < 0)
+            result = PY_OFF_T_MIN;
+        else
+            result = PY_OFF_T_MAX;
+    }
+    else {
+        /* Otherwise replace the error with caller's error object. */
+        PyErr_Format(err,
+                     "cannot fit '%.200s' into an offset-sized integer",
+                     item->ob_type->tp_name);
+    }
+
+ finish:
+    Py_DECREF(value);
+    return result;
+}
+
+/*
+ * Module definition
+ */
+
+static PyMethodDef module_methods[] = {
+    {"open", (PyCFunction)io_open, METH_VARARGS|METH_KEYWORDS, open_doc},
+    {NULL, NULL}
+};
+
+static struct PyModuleDef iomodule = {
+    PyModuleDef_HEAD_INIT,
+    "io",
+    module_doc,
+    -1,
+    module_methods,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC
+PyInit__io(void)
+{
+    PyObject *m = PyModule_Create(&iomodule);
+    PyTypeObject *base;
+    if (m == NULL)
+        goto fail;
+
+    /* UnsupportedOperation inherits from ValueError and IOError */
+    PyIOExc_UnsupportedOperation = PyObject_CallFunction(
+        (PyObject *)&PyType_Type, "s(OO){}",
+        "UnsupportedOperation", PyExc_ValueError, PyExc_IOError);
+    if (PyIOExc_UnsupportedOperation == NULL)
+        goto fail;
+    PyModule_AddObject(m, "UnsupportedOperation",
+                       PyIOExc_UnsupportedOperation);
+
+    /* BlockingIOError */
+    base = (PyTypeObject *)PyExc_IOError;
+    _PyExc_BlockingIOError.tp_base = base;
+    if (PyType_Ready(&_PyExc_BlockingIOError) < 0)
+        goto fail;
+    Py_INCREF(&_PyExc_BlockingIOError);
+    PyModule_AddObject(m, "BlockingIOError",
+                       (PyObject *)&_PyExc_BlockingIOError);
+
+    if (PyType_Ready(&PyIOBase_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyIOBase_Type);
+    PyModule_AddObject(m, "IOBase",
+                       (PyObject *)&PyIOBase_Type);
+
+    if (PyType_Ready(&PyRawIOBase_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyRawIOBase_Type);
+    PyModule_AddObject(m, "RawIOBase",
+                       (PyObject *)&PyRawIOBase_Type);
+
+    /* FileIO */
+    PyFileIO_Type.tp_base = &PyRawIOBase_Type;
+    if (PyType_Ready(&PyFileIO_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyFileIO_Type);
+    PyModule_AddObject(m, "FileIO", (PyObject *) &PyFileIO_Type);
+
+    /* BufferedIOBase */
+    if (PyType_Ready(&PyBufferedIOBase_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyBufferedIOBase_Type);
+    PyModule_AddObject(m, "BufferedIOBase", (PyObject *) &PyBufferedIOBase_Type);
+
+    /* BytesIO */
+    PyBytesIO_Type.tp_base = &PyBufferedIOBase_Type;
+    if (PyType_Ready(&PyBytesIO_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyBytesIO_Type);
+    PyModule_AddObject(m, "BytesIO", (PyObject *) &PyBytesIO_Type);
+
+    /* BufferedReader */
+    PyBufferedReader_Type.tp_base = &PyBufferedIOBase_Type;
+    if (PyType_Ready(&PyBufferedReader_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyBufferedReader_Type);
+    PyModule_AddObject(m, "BufferedReader", (PyObject *) &PyBufferedReader_Type);
+
+    /* BufferedWriter */
+    PyBufferedWriter_Type.tp_base = &PyBufferedIOBase_Type;
+    if (PyType_Ready(&PyBufferedWriter_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyBufferedWriter_Type);
+    PyModule_AddObject(m, "BufferedWriter", (PyObject *) &PyBufferedWriter_Type);
+
+    /* BufferedRWPair */
+    PyBufferedRWPair_Type.tp_base = &PyBufferedIOBase_Type;
+    if (PyType_Ready(&PyBufferedRWPair_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyBufferedRWPair_Type);
+    PyModule_AddObject(m, "BufferedRWPair", (PyObject *) &PyBufferedRWPair_Type);
+
+    /* BufferedRandom */
+    PyBufferedRandom_Type.tp_base = &PyBufferedIOBase_Type;
+    if (PyType_Ready(&PyBufferedRandom_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyBufferedRandom_Type);
+    PyModule_AddObject(m, "BufferedRandom", (PyObject *) &PyBufferedRandom_Type);
+
+    /* TextIOWrapper */
+    PyTextIOWrapper_Type.tp_base = &PyIOBase_Type;
+    if (PyType_Ready(&PyTextIOWrapper_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyTextIOWrapper_Type);
+    PyModule_AddObject(m, "TextIOWrapper", (PyObject *) &PyTextIOWrapper_Type);
+
+    /* TextIOWrapper */
+    if (PyType_Ready(&PyIncrementalNewlineDecoder_Type) < 0)
+        goto fail;
+    Py_INCREF(&PyIncrementalNewlineDecoder_Type);
+    PyModule_AddObject(m, "IncrementalNewlineDecoder", (PyObject *) &PyIncrementalNewlineDecoder_Type);
+
+    /* Interned strings */
+    if (!(_PyIO_str_close = PyUnicode_InternFromString("close")))
+        goto fail;
+    if (!(_PyIO_str_closed = PyUnicode_InternFromString("closed")))
+        goto fail;
+    if (!(_PyIO_str_decode = PyUnicode_InternFromString("decode")))
+        goto fail;
+    if (!(_PyIO_str_encode = PyUnicode_InternFromString("encode")))
+        goto fail;
+    if (!(_PyIO_str_fileno = PyUnicode_InternFromString("fileno")))
+        goto fail;
+    if (!(_PyIO_str_flush = PyUnicode_InternFromString("flush")))
+        goto fail;
+    if (!(_PyIO_str_getstate = PyUnicode_InternFromString("getstate")))
+        goto fail;
+    if (!(_PyIO_str_isatty = PyUnicode_InternFromString("isatty")))
+        goto fail;
+    if (!(_PyIO_str_newlines = PyUnicode_InternFromString("newlines")))
+        goto fail;
+    if (!(_PyIO_str_read = PyUnicode_InternFromString("read")))
+        goto fail;
+    if (!(_PyIO_str_read1 = PyUnicode_InternFromString("read1")))
+        goto fail;
+    if (!(_PyIO_str_readable = PyUnicode_InternFromString("readable")))
+        goto fail;
+    if (!(_PyIO_str_readinto = PyUnicode_InternFromString("readinto")))
+        goto fail;
+    if (!(_PyIO_str_readline = PyUnicode_InternFromString("readline")))
+        goto fail;
+    if (!(_PyIO_str_seek = PyUnicode_InternFromString("seek")))
+        goto fail;
+    if (!(_PyIO_str_seekable = PyUnicode_InternFromString("seekable")))
+        goto fail;
+    if (!(_PyIO_str_tell = PyUnicode_InternFromString("tell")))
+        goto fail;
+    if (!(_PyIO_str_truncate = PyUnicode_InternFromString("truncate")))
+        goto fail;
+    if (!(_PyIO_str_write = PyUnicode_InternFromString("write")))
+        goto fail;
+    if (!(_PyIO_str_writable = PyUnicode_InternFromString("writable")))
+        goto fail;
+
+    return m;
+
+  fail:
+    Py_XDECREF(m);
+    return NULL;
+}

Modified: python/branches/io-c/setup.py
==============================================================================
--- python/branches/io-c/setup.py	(original)
+++ python/branches/io-c/setup.py	Sun Jan 18 00:13:48 2009
@@ -996,8 +996,6 @@
         # Thomas Heller's _ctypes module
         self.detect_ctypes(inc_dirs, lib_dirs)
 
-        # _fileio -- supposedly cross platform
-        exts.append(Extension('_fileio', ['_fileio.c']))
         # Richard Oudkerk's multiprocessing module
         if platform == 'win32':             # Windows
             macros = dict()


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