diff --git a/Doc/ACKS.txt b/Doc/ACKS.txt
index 7f67d36..755f647 100644
--- a/Doc/ACKS.txt
+++ b/Doc/ACKS.txt
@@ -202,6 +202,7 @@
    * Jim Tittsler
    * David Turner
    * Ville Vainio
+   * Nadeem Vawda
    * Martijn Vries
    * Charles G. Waldman
    * Greg Ward
diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst
index d9a2bad..2ccdb51 100644
--- a/Doc/library/bz2.rst
+++ b/Doc/library/bz2.rst
@@ -1,189 +1,149 @@
-:mod:`bz2` --- Compression compatible with :program:`bzip2`
-===========================================================
+:mod:`bz2` --- Support for :program:`bzip2` compression
+=======================================================
 
 .. module:: bz2
-   :synopsis: Interface to compression and decompression routines
-              compatible with bzip2.
+   :synopsis: Interfaces for bzip2 compression and decompression.
 .. moduleauthor:: Gustavo Niemeyer <niemeyer@conectiva.com>
+.. moduleauthor:: Nadeem Vawda <nadeem.vawda@gmail.com>
 .. sectionauthor:: Gustavo Niemeyer <niemeyer@conectiva.com>
+.. sectionauthor:: Nadeem Vawda <nadeem.vawda@gmail.com>
 
 
-This module provides a comprehensive interface for the bz2 compression library.
-It implements a complete file interface, one-shot (de)compression functions, and
-types for sequential (de)compression.
+This module provides a comprehensive interface for compressing and
+decompressing data using the bzip2 compression algorithm.
 
-For other archive formats, see the :mod:`gzip`, :mod:`zipfile`, and
+For related file formats, see the :mod:`gzip`, :mod:`zipfile`, and
 :mod:`tarfile` modules.
 
-Here is a summary of the features offered by the bz2 module:
+The :mod:`bz2` module contains:
 
-* :class:`BZ2File` class implements a complete file interface, including
-  :meth:`~BZ2File.readline`, :meth:`~BZ2File.readlines`,
-  :meth:`~BZ2File.writelines`, :meth:`~BZ2File.seek`, etc;
+* The :class:`BZ2File` class for reading and writing compressed files.
+* The :class:`BZ2Compressor` and :class:`BZ2Decompressor` classes for
+  incremental (de)compression.
+* The :func:`compress` and :func:`decompress` functions for one-shot
+  (de)compression.
 
-* :class:`BZ2File` class implements emulated :meth:`~BZ2File.seek` support;
-
-* :class:`BZ2File` class implements universal newline support;
-
-* :class:`BZ2File` class offers an optimized line iteration using a readahead
-  algorithm;
-
-* Sequential (de)compression supported by :class:`BZ2Compressor` and
-  :class:`BZ2Decompressor` classes;
-
-* One-shot (de)compression supported by :func:`compress` and :func:`decompress`
-  functions;
-
-* Thread safety uses individual locking mechanism.
+All of the classes in this module may safely be accessed from multiple threads.
 
 
 (De)compression of files
 ------------------------
 
-Handling of compressed files is offered by the :class:`BZ2File` class.
+.. class:: BZ2File(filename=None, mode='r', buffering=None, compresslevel=9, fileobj=None)
 
+   Open a bzip2-compressed file.
 
-.. class:: BZ2File(filename, mode='r', buffering=0, compresslevel=9)
+   The :class:`BZ2File` can wrap an existing :term:`file object` (given by
+   *fileobj*), or operate directly on a named file (named by *filename*).
+   Exactly one of these two parameters should be provided.
 
-   Open a bz2 file. Mode can be either ``'r'`` or ``'w'``, for reading (default)
-   or writing. When opened for writing, the file will be created if it doesn't
-   exist, and truncated otherwise. If *buffering* is given, ``0`` means
-   unbuffered, and larger numbers specify the buffer size; the default is
-   ``0``. If *compresslevel* is given, it must be a number between ``1`` and
-   ``9``; the default is ``9``. Add a ``'U'`` to mode to open the file for input
-   with universal newline support. Any line ending in the input file will be
-   seen as a ``'\n'`` in Python.  Also, a file so opened gains the attribute
-   :attr:`newlines`; the value for this attribute is one of ``None`` (no newline
-   read yet), ``'\r'``, ``'\n'``, ``'\r\n'`` or a tuple containing all the
-   newline types seen. Universal newlines are available only when
-   reading. Instances support iteration in the same way as normal :class:`file`
-   instances.
+   The *mode* argument can be either ``'r'`` for reading (default), or ``'w'``
+   for writing.
 
-   :class:`BZ2File` supports the :keyword:`with` statement.
+   The *buffering* argument is ignored. Its use is deprecated.
+
+   If *mode* is ``'w'``, *compresslevel* can be a number between ``1`` and
+   ``9`` specifying the level of compression: ``1`` produces the least
+   compression, and ``9`` (default) produces the most compression.
+
+   :class:`BZ2File` provides all of the members specified by the
+   :class:`io.BufferedIOBase`, except for :meth:`detach` and :meth:`truncate`.
+   Iteration and the :keyword:`with` statement are supported.
+
+   :class:`BZ2File` also provides the following method:
+
+   .. method:: peek([n])
+
+      Return buffered data without advancing the file position. At least one
+      byte of data will be returned (unless at EOF). The exact number of bytes
+      returned is unspecified.
+
+      .. versionadded:: 3.3
 
    .. versionchanged:: 3.1
       Support for the :keyword:`with` statement was added.
 
+   .. versionchanged:: 3.3
+      The :meth:`fileno`, :meth:`readable`, :meth:`seekable`, :meth:`writable`,
+      :meth:`read1` and :meth:`readinto` methods were added.
 
-   .. method:: close()
-
-      Close the file. Sets data attribute :attr:`closed` to true. A closed file
-      cannot be used for further I/O operations. :meth:`close` may be called
-      more than once without error.
+   .. versionchanged:: 3.3
+      The *fileobj* argument to the constructor was added.
 
 
-   .. method:: read([size])
-
-      Read at most *size* uncompressed bytes, returned as a byte string. If the
-      *size* argument is negative or omitted, read until EOF is reached.
-
-
-   .. method:: readline([size])
-
-      Return the next line from the file, as a byte string, retaining newline.
-      A non-negative *size* argument limits the maximum number of bytes to
-      return (an incomplete line may be returned then). Return an empty byte
-      string at EOF.
-
-
-   .. method:: readlines([size])
-
-      Return a list of lines read. The optional *size* argument, if given, is an
-      approximate bound on the total number of bytes in the lines returned.
-
-
-   .. method:: seek(offset[, whence])
-
-      Move to new file position. Argument *offset* is a byte count. Optional
-      argument *whence* defaults to ``os.SEEK_SET`` or ``0`` (offset from start
-      of file; offset should be ``>= 0``); other values are ``os.SEEK_CUR`` or
-      ``1`` (move relative to current position; offset can be positive or
-      negative), and ``os.SEEK_END`` or ``2`` (move relative to end of file;
-      offset is usually negative, although many platforms allow seeking beyond
-      the end of a file).
-
-      Note that seeking of bz2 files is emulated, and depending on the
-      parameters the operation may be extremely slow.
-
-
-   .. method:: tell()
-
-      Return the current file position, an integer.
-
-
-   .. method:: write(data)
-
-      Write the byte string *data* to file. Note that due to buffering,
-      :meth:`close` may be needed before the file on disk reflects the data
-      written.
-
-
-   .. method:: writelines(sequence_of_byte_strings)
-
-      Write the sequence of byte strings to the file. Note that newlines are not
-      added. The sequence can be any iterable object producing byte strings.
-      This is equivalent to calling write() for each byte string.
-
-
-Sequential (de)compression
---------------------------
-
-Sequential compression and decompression is done using the classes
-:class:`BZ2Compressor` and :class:`BZ2Decompressor`.
-
+Incremental (de)compression
+---------------------------
 
 .. class:: BZ2Compressor(compresslevel=9)
 
    Create a new compressor object. This object may be used to compress data
-   sequentially. If you want to compress data in one shot, use the
-   :func:`compress` function instead. The *compresslevel* parameter, if given,
-   must be a number between ``1`` and ``9``; the default is ``9``.
+   incrementally. For one-shot compression, use the :func:`compress` function
+   instead.
+
+   *compresslevel*, if given, must be a number between ``1`` and ``9``. The
+   default is ``9``.
 
    .. method:: compress(data)
 
-      Provide more data to the compressor object. It will return chunks of
-      compressed data whenever possible. When you've finished providing data to
-      compress, call the :meth:`flush` method to finish the compression process,
-      and return what is left in internal buffers.
+      Provide data to the compressor object. Returns a chunk of compressed data
+      if possible, or an empty byte string otherwise.
+
+      When you have finished providing data to the compressor, call the
+      :meth:`flush` method to finish the compression process.
 
 
    .. method:: flush()
 
-      Finish the compression process and return what is left in internal
-      buffers. You must not use the compressor object after calling this method.
+      Finish the compression process. Returns the compressed data left in
+      internal buffers.
+
+      The compressor object may not be used after this method has been called.
 
 
 .. class:: BZ2Decompressor()
 
    Create a new decompressor object. This object may be used to decompress data
-   sequentially. If you want to decompress data in one shot, use the
-   :func:`decompress` function instead.
+   incrementally. For one-shot compression, use the :func:`decompress` function
+   instead.
 
    .. method:: decompress(data)
 
-      Provide more data to the decompressor object. It will return chunks of
-      decompressed data whenever possible. If you try to decompress data after
-      the end of stream is found, :exc:`EOFError` will be raised. If any data
-      was found after the end of stream, it'll be ignored and saved in
-      :attr:`unused_data` attribute.
+      Provide data to the decompressor object. Returns a chunk of decompressed
+      data if possible, or an empty byte string otherwise.
+
+      Attempting to decompress data after the end of stream is reached raises
+      an :exc:`EOFError`. If any data is found after the end of the stream, it
+      is ignored and saved in the :attr:`unused_data` attribute.
+
+
+   .. attribute:: eof
+
+      True if the end-of-stream marker has been reached.
+
+      .. versionadded:: 3.3
+
+
+   .. attribute:: unused_data
+
+      Data found after the end of the compressed stream.
 
 
 One-shot (de)compression
 ------------------------
 
-One-shot compression and decompression is provided through the :func:`compress`
-and :func:`decompress` functions.
-
-
 .. function:: compress(data, compresslevel=9)
 
-   Compress *data* in one shot. If you want to compress data sequentially, use
-   an instance of :class:`BZ2Compressor` instead. The *compresslevel* parameter,
-   if given, must be a number between ``1`` and ``9``; the default is ``9``.
+   Compress *data*.
+
+   *compresslevel*, if given, must be a number between ``1`` and ``9``. The
+   default is ``9``.
+
+   For incremental compression, use a :class:`BZ2Compressor` instead.
 
 
 .. function:: decompress(data)
 
-   Decompress *data* in one shot. If you want to decompress data sequentially,
-   use an instance of :class:`BZ2Decompressor` instead.
+   Decompress *data*.
+
+   For incremental decompression, use a :class:`BZ2Decompressor` instead.
 
diff --git a/Lib/bz2.py b/Lib/bz2.py
new file mode 100644
index 0000000..667fffd
--- /dev/null
+++ b/Lib/bz2.py
@@ -0,0 +1,392 @@
+"""Interface to the libbzip2 compression library.
+
+This module provides a file interface, classes for incremental
+(de)compression, and functions for one-shot (de)compression.
+"""
+
+__all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor", "compress",
+           "decompress"]
+
+__author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>"
+
+import io
+import threading
+import warnings
+
+from _bz2 import BZ2Compressor, BZ2Decompressor
+
+
+_MODE_CLOSED   = 0
+_MODE_READ     = 1
+_MODE_READ_EOF = 2
+_MODE_WRITE    = 3
+
+_BUFFER_SIZE = 8192
+
+
+class BZ2File(io.BufferedIOBase):
+
+    """A file object providing transparent bzip2 (de)compression.
+
+    A BZ2File can act as a wrapper for an existing file object, or refer
+    directly to a named file on disk.
+
+    Note that BZ2File provides a *binary* file interface - data read is
+    returned as bytes, and data to be written should be given as bytes.
+    """
+
+    def __init__(self, filename=None, mode="r", buffering=None,
+                 compresslevel=9, fileobj=None):
+        """Open a bzip2-compressed file.
+
+        If filename is given, open the named file. Otherwise, operate on
+        the file object given by fileobj. Exactly one of these two
+        parameters should be provided.
+
+        mode can be 'r' for reading (default), or 'w' for writing.
+
+        buffering is ignored. Its use is deprecated.
+
+        If mode is 'w', compresslevel can be a number between 1 and 9
+        specifying the level of compression: 1 produces the least
+        compression, and 9 (default) produces the most compression.
+        """
+        # This lock must be recursive, so that BufferedIOBase's
+        # readline(), readlines() and writelines() don't deadlock.
+        self._lock = threading.RLock()
+        self._fp = None
+        self._closefp = False
+        self._mode = _MODE_CLOSED
+        self._pos = 0
+        self._size = -1
+
+        if buffering is not None:
+            warnings.warn("Use of 'buffering' argument is deprecated",
+                          DeprecationWarning)
+
+        if not (1 <= compresslevel <= 9):
+            raise ValueError("compresslevel must be between 1 and 9")
+
+        if mode in ("", "r", "rb"):
+            mode = "rb"
+            mode_code = _MODE_READ
+            self._decompressor = BZ2Decompressor()
+            self._buffer = None
+        elif mode in ("w", "wb"):
+            mode = "wb"
+            mode_code = _MODE_WRITE
+            self._compressor = BZ2Compressor()
+        else:
+            raise ValueError("Invalid mode: {!r}".format(mode))
+
+        if filename is not None and fileobj is None:
+            self._fp = open(filename, mode)
+            self._closefp = True
+            self._mode = mode_code
+        elif fileobj is not None and filename is None:
+            self._fp = fileobj
+            self._mode = mode_code
+        else:
+            raise ValueError("Must give exactly one of filename and fileobj")
+
+    def close(self):
+        """Flush and close the file.
+
+        May be called more than once without error. Once the file is
+        closed, any other operation on it will raise a ValueError.
+        """
+        with self._lock:
+            if self._mode == _MODE_CLOSED:
+                return
+            try:
+                if self._mode in (_MODE_READ, _MODE_READ_EOF):
+                    self._decompressor = None
+                elif self._mode == _MODE_WRITE:
+                    self._fp.write(self._compressor.flush())
+                    self._compressor = None
+            finally:
+                try: 
+                    if self._closefp:
+                        self._fp.close()
+                finally:
+                    self._fp = None
+                    self._closefp = False
+                    self._mode = _MODE_CLOSED
+                    self._buffer = None
+
+    @property
+    def closed(self):
+        """True if this file is closed."""
+        return self._mode == _MODE_CLOSED
+
+    def fileno(self):
+        """Return the file descriptor for the underlying file."""
+        return self._fp.fileno()
+
+    def seekable(self):
+        """Return whether the file supports seeking."""
+        return self.readable()
+
+    def readable(self):
+        """Return whether the file was opened for reading."""
+        return self._mode in (_MODE_READ, _MODE_READ_EOF)
+
+    def writable(self):
+        """Return whether the file was opened for writing."""
+        return self._mode == _MODE_WRITE
+
+    # Mode-checking helper functions.
+
+    def _check_not_closed(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+
+    def _check_can_read(self):
+        if not self.readable():
+            self._check_not_closed()
+            raise io.UnsupportedOperation("File not open for reading")
+
+    def _check_can_write(self):
+        if not self.writable():
+            self._check_not_closed()
+            raise io.UnsupportedOperation("File not open for writing")
+
+    def _check_can_seek(self):
+        if not self.seekable():
+            self._check_not_closed()
+            raise io.UnsupportedOperation("Seeking is only supported "
+                                          "on files opening for reading")
+
+    # Fill the readahead buffer if it is empty. Returns False on EOF.
+    def _fill_buffer(self):
+        if self._buffer:
+            return True
+        if self._decompressor.eof:
+            self._mode = _MODE_READ_EOF
+            self._size = self._pos
+            return False
+        rawblock = self._fp.read(_BUFFER_SIZE)
+        if not rawblock:
+            raise EOFError("Compressed file ended before the "
+                           "end-of-stream marker was reached")
+        self._buffer = self._decompressor.decompress(rawblock)
+        return True
+
+    # Read data until EOF.
+    # If return_data is false, consume the data without returning it.
+    def _read_all(self, return_data=True):
+        blocks = []
+        while self._fill_buffer():
+            if return_data:
+                blocks.append(self._buffer)
+            self._pos += len(self._buffer)
+            self._buffer = None
+        if return_data:
+            return b"".join(blocks)
+
+    # Read a block of up to n bytes.
+    # If return_data is false, consume the data without returning it.
+    def _read_block(self, n, return_data=True):
+        blocks = []
+        while n > 0 and self._fill_buffer():
+            if n < len(self._buffer):
+                data = self._buffer[:n]
+                self._buffer = self._buffer[n:]
+            else:
+                data = self._buffer
+                self._buffer = None
+            if return_data:
+                blocks.append(data)
+            self._pos += len(data)
+            n -= len(data)
+        if return_data:
+            return b"".join(blocks)
+
+    def peek(self, n=0):
+        """Return buffered data without advancing the file position.
+
+        Always returns at least one byte of data, unless at EOF.
+        The exact number of bytes returned is unspecified.
+        """
+        with self._lock:
+            self._check_can_read()
+            if self._mode == _MODE_READ_EOF or not self._fill_buffer():
+                return b""
+            return self._buffer
+
+    def read(self, size=-1):
+        """Read up to size uncompressed bytes from the file.
+
+        If size is negative or omitted, read until EOF is reached.
+        Returns b'' if the file is already at EOF.
+        """
+        with self._lock:
+            self._check_can_read()
+            if self._mode == _MODE_READ_EOF or size == 0:
+                return b""
+            elif size < 0:
+                return self._read_all()
+            else:
+                return self._read_block(size)
+
+    def read1(self, size=-1):
+        """Read up to size uncompressed bytes with at most one read
+        from the underlying stream.
+
+        Returns b'' if the file is at EOF.
+        """
+        with self._lock:
+            self._check_can_read()
+            if (size == 0 or self._mode == _MODE_READ_EOF or
+                not self._fill_buffer()):
+                return b""
+            if 0 < size < len(self._buffer):
+                data = self._buffer[:size]
+                self._buffer = self._buffer[size:]
+            else:
+                data = self._buffer
+                self._buffer = None
+            self._pos += len(data)
+            return data
+
+    def readinto(self, b):
+        """Read up to len(b) bytes into b.
+        
+        Returns the number of bytes read (0 for EOF).
+        """
+        with self._lock:
+            return io.BufferedIOBase.readinto(self, b)
+
+    def readline(self, size=-1):
+        """Read a line of uncompressed bytes from the file.
+
+        The terminating newline (if present) is retained. If size is
+        non-negative, no more than size bytes will be read (in which
+        case the line may be incomplete). Returns b'' if already at EOF.
+        """
+        if not hasattr(size, "__index__"):
+            raise TypeError("Integer argument expected")
+        size = size.__index__()
+        with self._lock:
+            return io.BufferedIOBase.readline(self, size)
+
+    def readlines(self, size=-1):
+        """Read a list of lines of uncompressed bytes from the file.
+
+        size can be specified to control the number of lines read: no
+        further lines will be read once the total size of the lines read
+        so far equals or exceeds size.
+        """
+        if not hasattr(size, "__index__"):
+            raise TypeError("Integer argument expected")
+        size = size.__index__()
+        with self._lock:
+            return io.BufferedIOBase.readlines(self, size)
+
+    def write(self, data):
+        """Write a byte string to the file.
+
+        Returns the number of uncompressed bytes written, which is
+        always len(data). Note that due to buffering, the file on disk
+        may not reflect the data written until close() is called.
+        """
+        with self._lock:
+            self._check_can_write()
+            compressed = self._compressor.compress(data)
+            self._fp.write(compressed)
+            self._pos += len(data)
+            return len(data)
+
+    def writelines(self, seq):
+        """Write a sequence of byte strings to the file.
+
+        Returns the number of uncompressed bytes written.
+        seq can be any iterable yielding byte strings.
+
+        Line separators are not added between the written byte strings.
+        """
+        with self._lock:
+            return io.BufferedIOBase.writelines(self, seq)
+
+    # Rewind the file to the beginning of the data stream.
+    def _rewind(self):
+        self._fp.seek(0, 0)
+        self._mode = _MODE_READ
+        self._pos = 0
+        self._decompressor = BZ2Decompressor()
+        self._buffer = None
+
+    def seek(self, offset, whence=0):
+        """Change the file position.
+
+        The new position is specified by offset, relative to the
+        position indicated by whence. Values for whence are:
+
+            0: start of stream (default); offset must not be negative
+            1: current stream position
+            2: end of stream; offset must not be positive
+
+        Returns the new file position.
+
+        Note that seeking is emulated, so depending on the parameters,
+        this operation may be extremely slow.
+        """
+        with self._lock:
+            self._check_can_seek()
+
+            # Recalculate offset as an absolute file position.
+            if whence == 0:
+                pass
+            elif whence == 1:
+                offset = self._pos + offset
+            elif whence == 2:
+                # Seeking relative to EOF - we need to know the file's size.
+                if self._size < 0:
+                    self._read_all(return_data=False)
+                offset = self._size + offset
+            else:
+                raise ValueError("Invalid value for whence: {}".format(whence))
+
+            # Make it so that offset is the number of bytes to skip forward.
+            if offset < self._pos:
+                self._rewind()
+            else:
+                offset -= self._pos
+
+            # Read and discard data until we reach the desired position.
+            if self._mode != _MODE_READ_EOF:
+                self._read_block(offset, return_data=False)
+
+            return self._pos
+
+    def tell(self):
+        """Return the current file position."""
+        with self._lock:
+            self._check_not_closed()
+            return self._pos
+
+
+def compress(data, compresslevel=9):
+    """Compress a block of data.
+
+    compresslevel, if given, must be a number between 1 and 9.
+
+    For incremental compression, use a BZ2Compressor object instead.
+    """
+    comp = BZ2Compressor(compresslevel)
+    return comp.compress(data) + comp.flush()
+
+
+def decompress(data):
+    """Decompress a block of data.
+
+    For incremental decompression, use a BZ2Decompressor object instead.
+    """
+    if len(data) == 0:
+        return b""
+    decomp = BZ2Decompressor()
+    result = decomp.decompress(data)
+    if not decomp.eof:
+        raise ValueError("Compressed data ended before the "
+                         "end-of-stream marker was reached")
+    return result
diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index be35580..cee38e0 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -21,7 +21,30 @@
 
 class BaseTest(unittest.TestCase):
     "Base for other testcases."
-    TEXT = b'root:x:0:0:root:/root:/bin/bash\nbin:x:1:1:bin:/bin:\ndaemon:x:2:2:daemon:/sbin:\nadm:x:3:4:adm:/var/adm:\nlp:x:4:7:lp:/var/spool/lpd:\nsync:x:5:0:sync:/sbin:/bin/sync\nshutdown:x:6:0:shutdown:/sbin:/sbin/shutdown\nhalt:x:7:0:halt:/sbin:/sbin/halt\nmail:x:8:12:mail:/var/spool/mail:\nnews:x:9:13:news:/var/spool/news:\nuucp:x:10:14:uucp:/var/spool/uucp:\noperator:x:11:0:operator:/root:\ngames:x:12:100:games:/usr/games:\ngopher:x:13:30:gopher:/usr/lib/gopher-data:\nftp:x:14:50:FTP User:/var/ftp:/bin/bash\nnobody:x:65534:65534:Nobody:/home:\npostfix:x:100:101:postfix:/var/spool/postfix:\nniemeyer:x:500:500::/home/niemeyer:/bin/bash\npostgres:x:101:102:PostgreSQL Server:/var/lib/pgsql:/bin/bash\nmysql:x:102:103:MySQL server:/var/lib/mysql:/bin/bash\nwww:x:103:104::/var/www:/bin/false\n'
+    TEXT_LINES = [
+        b'root:x:0:0:root:/root:/bin/bash\n',
+        b'bin:x:1:1:bin:/bin:\n',
+        b'daemon:x:2:2:daemon:/sbin:\n',
+        b'adm:x:3:4:adm:/var/adm:\n',
+        b'lp:x:4:7:lp:/var/spool/lpd:\n',
+        b'sync:x:5:0:sync:/sbin:/bin/sync\n',
+        b'shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown\n',
+        b'halt:x:7:0:halt:/sbin:/sbin/halt\n',
+        b'mail:x:8:12:mail:/var/spool/mail:\n',
+        b'news:x:9:13:news:/var/spool/news:\n',
+        b'uucp:x:10:14:uucp:/var/spool/uucp:\n',
+        b'operator:x:11:0:operator:/root:\n',
+        b'games:x:12:100:games:/usr/games:\n',
+        b'gopher:x:13:30:gopher:/usr/lib/gopher-data:\n',
+        b'ftp:x:14:50:FTP User:/var/ftp:/bin/bash\n',
+        b'nobody:x:65534:65534:Nobody:/home:\n',
+        b'postfix:x:100:101:postfix:/var/spool/postfix:\n',
+        b'niemeyer:x:500:500::/home/niemeyer:/bin/bash\n',
+        b'postgres:x:101:102:PostgreSQL Server:/var/lib/pgsql:/bin/bash\n',
+        b'mysql:x:102:103:MySQL server:/var/lib/mysql:/bin/bash\n',
+        b'www:x:103:104::/var/www:/bin/false\n',
+        ]
+    TEXT = b''.join(TEXT_LINES)
     DATA = b'BZh91AY&SY.\xc8N\x18\x00\x01>_\x80\x00\x10@\x02\xff\xf0\x01\x07n\x00?\xe7\xff\xe00\x01\x99\xaa\x00\xc0\x03F\x86\x8c#&\x83F\x9a\x03\x06\xa6\xd0\xa6\x93M\x0fQ\xa7\xa8\x06\x804hh\x12$\x11\xa4i4\xf14S\xd2<Q\xb5\x0fH\xd3\xd4\xdd\xd5\x87\xbb\xf8\x94\r\x8f\xafI\x12\xe1\xc9\xf8/E\x00pu\x89\x12]\xc9\xbbDL\nQ\x0e\t1\x12\xdf\xa0\xc0\x97\xac2O9\x89\x13\x94\x0e\x1c7\x0ed\x95I\x0c\xaaJ\xa4\x18L\x10\x05#\x9c\xaf\xba\xbc/\x97\x8a#C\xc8\xe1\x8cW\xf9\xe2\xd0\xd6M\xa7\x8bXa<e\x84t\xcbL\xb3\xa7\xd9\xcd\xd1\xcb\x84.\xaf\xb3\xab\xab\xad`n}\xa0lh\tE,\x8eZ\x15\x17VH>\x88\xe5\xcd9gd6\x0b\n\xe9\x9b\xd5\x8a\x99\xf7\x08.K\x8ev\xfb\xf7xw\xbb\xdf\xa1\x92\xf1\xdd|/";\xa2\xba\x9f\xd5\xb1#A\xb6\xf6\xb3o\xc9\xc5y\\\xebO\xe7\x85\x9a\xbc\xb6f8\x952\xd5\xd7"%\x89>V,\xf7\xa6z\xe2\x9f\xa3\xdf\x11\x11"\xd6E)I\xa9\x13^\xca\xf3r\xd0\x03U\x922\xf26\xec\xb6\xed\x8b\xc3U\x13\x9d\xc5\x170\xa4\xfa^\x92\xacDF\x8a\x97\xd6\x19\xfe\xdd\xb8\xbd\x1a\x9a\x19\xa3\x80ankR\x8b\xe5\xd83]\xa9\xc6\x08\x82f\xf6\xb9"6l$\xb8j@\xc0\x8a\xb0l1..\xbak\x83ls\x15\xbc\xf4\xc1\x13\xbe\xf8E\xb8\x9d\r\xa8\x9dk\x84\xd3n\xfa\xacQ\x07\xb1%y\xaav\xb4\x08\xe0z\x1b\x16\xf5\x04\xe9\xcc\xb9\x08z\x1en7.G\xfc]\xc9\x14\xe1B@\xbb!8`'
     DATA_CRLF = b'BZh91AY&SY\xaez\xbbN\x00\x01H\xdf\x80\x00\x12@\x02\xff\xf0\x01\x07n\x00?\xe7\xff\xe0@\x01\xbc\xc6`\x86*\x8d=M\xa9\x9a\x86\xd0L@\x0fI\xa6!\xa1\x13\xc8\x88jdi\x8d@\x03@\x1a\x1a\x0c\x0c\x83 \x00\xc4h2\x19\x01\x82D\x84e\t\xe8\x99\x89\x19\x1ah\x00\r\x1a\x11\xaf\x9b\x0fG\xf5(\x1b\x1f?\t\x12\xcf\xb5\xfc\x95E\x00ps\x89\x12^\xa4\xdd\xa2&\x05(\x87\x04\x98\x89u\xe40%\xb6\x19\'\x8c\xc4\x89\xca\x07\x0e\x1b!\x91UIFU%C\x994!DI\xd2\xfa\xf0\xf1N8W\xde\x13A\xf5\x9cr%?\x9f3;I45A\xd1\x8bT\xb1<l\xba\xcb_\xc00xY\x17r\x17\x88\x08\x08@\xa0\ry@\x10\x04$)`\xf2\xce\x89z\xb0s\xec\x9b.iW\x9d\x81\xb5-+t\x9f\x1a\'\x97dB\xf5x\xb5\xbe.[.\xd7\x0e\x81\xe7\x08\x1cN`\x88\x10\xca\x87\xc3!"\x80\x92R\xa1/\xd1\xc0\xe6mf\xac\xbd\x99\xcca\xb3\x8780>\xa4\xc7\x8d\x1a\\"\xad\xa1\xabyBg\x15\xb9l\x88\x88\x91k"\x94\xa4\xd4\x89\xae*\xa6\x0b\x10\x0c\xd6\xd4m\xe86\xec\xb5j\x8a\x86j\';\xca.\x01I\xf2\xaaJ\xe8\x88\x8cU+t3\xfb\x0c\n\xa33\x13r2\r\x16\xe0\xb3(\xbf\x1d\x83r\xe7M\xf0D\x1365\xd8\x88\xd3\xa4\x92\xcb2\x06\x04\\\xc1\xb0\xea//\xbek&\xd8\xe6+t\xe5\xa1\x13\xada\x16\xder5"w]\xa2i\xb7[\x97R \xe2IT\xcd;Z\x04dk4\xad\x8a\t\xd3\x81z\x10\xf1:^`\xab\x1f\xc5\xdc\x91N\x14$+\x9e\xae\xd3\x80'
 
@@ -54,13 +77,15 @@
         if os.path.isfile(self.filename):
             os.unlink(self.filename)
 
-    def createTempFile(self, crlf=0):
+    def getData(self, crlf=False):
+        if crlf:
+            return self.DATA_CRLF
+        else:
+            return self.DATA
+
+    def createTempFile(self, crlf=False):
         with open(self.filename, "wb") as f:
-            if crlf:
-                data = self.DATA_CRLF
-            else:
-                data = self.DATA
-            f.write(data)
+            f.write(self.getData(crlf))
 
     def testRead(self):
         # "Test BZ2File.read()"
@@ -70,7 +95,7 @@
             self.assertEqual(bz2f.read(), self.TEXT)
 
     def testRead0(self):
-        # Test BBZ2File.read(0)"
+        # "Test BBZ2File.read(0)"
         self.createTempFile()
         with BZ2File(self.filename) as bz2f:
             self.assertRaises(TypeError, bz2f.read, None)
@@ -94,6 +119,28 @@
         with BZ2File(self.filename) as bz2f:
             self.assertEqual(bz2f.read(100), self.TEXT[:100])
 
+    def testPeek(self):
+        # "Test BZ2File.peek()"
+        self.createTempFile()
+        with BZ2File(self.filename) as bz2f:
+            pdata = bz2f.peek()
+            self.assertNotEqual(len(pdata), 0)
+            self.assertTrue(self.TEXT.startswith(pdata))
+            self.assertEqual(bz2f.read(), self.TEXT)
+
+    def testReadInto(self):
+        # "Test BZ2File.readinto()"
+        self.createTempFile()
+        with BZ2File(self.filename) as bz2f:
+            n = 128
+            b = bytearray(n)
+            self.assertEqual(bz2f.readinto(b), n)
+            self.assertEqual(b, self.TEXT[:n])
+            n = len(self.TEXT) - n
+            b = bytearray(len(self.TEXT))
+            self.assertEqual(bz2f.readinto(b), n)
+            self.assertEqual(b[:n], self.TEXT[-n:])
+
     def testReadLine(self):
         # "Test BZ2File.readline()"
         self.createTempFile()
@@ -125,7 +172,7 @@
         bz2f = BZ2File(self.filename)
         bz2f.close()
         self.assertRaises(ValueError, bz2f.__next__)
-        # This call will deadlock of the above .__next__ call failed to
+        # This call will deadlock if the above .__next__ call failed to
         # release the lock.
         self.assertRaises(ValueError, bz2f.readlines)
 
@@ -217,6 +264,13 @@
             self.assertEqual(bz2f.tell(), 0)
             self.assertEqual(bz2f.read(), self.TEXT)
 
+    def testFileno(self):
+        # "Test BZ2File.fileno()"
+        self.createTempFile()
+        with open(self.filename) as rawf:
+            with BZ2File(fileobj=rawf) as bz2f:
+                self.assertEqual(bz2f.fileno(), rawf.fileno())
+
     def testOpenDel(self):
         # "Test opening and deleting a file many times"
         self.createTempFile()
@@ -278,17 +332,65 @@
                 t.join()
 
     def testMixedIterationReads(self):
-        # Issue #8397: mixed iteration and reads should be forbidden.
-        with bz2.BZ2File(self.filename, 'wb') as f:
-            # The internal buffer size is hard-wired to 8192 bytes, we must
-            # write out more than that for the test to stop half through
-            # the buffer.
-            f.write(self.TEXT * 100)
-        with bz2.BZ2File(self.filename, 'rb') as f:
-            next(f)
-            self.assertRaises(ValueError, f.read)
-            self.assertRaises(ValueError, f.readline)
-            self.assertRaises(ValueError, f.readlines)
+        # "Test mixed iteration and reads."
+        self.createTempFile()
+        linelen = len(self.TEXT_LINES[0])
+        halflen = linelen // 2
+        with bz2.BZ2File(self.filename) as bz2f:
+            bz2f.read(halflen)
+            self.assertEqual(next(bz2f), self.TEXT_LINES[0][halflen:])
+            self.assertEqual(bz2f.read(), self.TEXT[linelen:])
+        with bz2.BZ2File(self.filename) as bz2f:
+            bz2f.readline()
+            self.assertEqual(next(bz2f), self.TEXT_LINES[1])
+            self.assertEqual(bz2f.readline(), self.TEXT_LINES[2])
+        with bz2.BZ2File(self.filename) as bz2f:
+            bz2f.readlines()
+            with self.assertRaises(StopIteration):
+                next(bz2f)
+            self.assertEqual(bz2f.readlines(), [])
+
+    def testReadBytesIO(self):
+        # "Test BZ2File.read() with BytesIO source"
+        with BytesIO(self.getData()) as bio:
+            with BZ2File(fileobj=bio) as bz2f:
+                self.assertRaises(TypeError, bz2f.read, None)
+                self.assertEqual(bz2f.read(), self.TEXT)
+            self.assertFalse(bio.closed)
+
+    def testPeekBytesIO(self):
+        # "Test BZ2File.peek() with BytesIO source"
+        with BytesIO(self.getData()) as bio:
+            with BZ2File(fileobj=bio) as bz2f:
+                pdata = bz2f.peek()
+                self.assertNotEqual(len(pdata), 0)
+                self.assertTrue(self.TEXT.startswith(pdata))
+                self.assertEqual(bz2f.read(), self.TEXT)
+
+    def testWriteBytesIO(self):
+        # "Test BZ2File.write() with BytesIO destination"
+        with BytesIO() as bio:
+            with BZ2File(fileobj=bio, mode="w") as bz2f:
+                self.assertRaises(TypeError, bz2f.write)
+                bz2f.write(self.TEXT)
+            self.assertEqual(self.decompress(bio.getvalue()), self.TEXT)
+            self.assertFalse(bio.closed)
+
+    def testSeekForwardBytesIO(self):
+        # "Test BZ2File.seek(150, 0) with BytesIO source"
+        with BytesIO(self.getData()) as bio:
+            with BZ2File(fileobj=bio) as bz2f:
+                self.assertRaises(TypeError, bz2f.seek)
+                bz2f.seek(150)
+                self.assertEqual(bz2f.read(), self.TEXT[150:])
+
+    def testSeekBackwardsBytesIO(self):
+        # "Test BZ2File.seek(-150, 1) with BytesIO source"
+        with BytesIO(self.getData()) as bio:
+            with BZ2File(fileobj=bio) as bz2f:
+                bz2f.read(500)
+                bz2f.seek(-150, 1)
+                self.assertEqual(bz2f.read(), self.TEXT[500-150:])
 
 class BZ2CompressorTest(BaseTest):
     def testCompress(self):
diff --git a/Misc/NEWS b/Misc/NEWS
index 45e9999..bba0f44 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -87,6 +87,10 @@
 Library
 -------
 
+- Issue #5863: Rewrite BZ2File in pure Python, and allow it to accept
+  file-like objects using a new ``fileobj`` constructor argument.  Patch by
+  Nadeem Vawda.
+
 - unittest.TestCase.assertSameElements has been removed.
 
 - sys.getfilesystemencoding() raises a RuntimeError if initfsencoding() was not
diff --git a/Modules/_bz2module.c b/Modules/_bz2module.c
new file mode 100644
index 0000000..522b3e5
--- /dev/null
+++ b/Modules/_bz2module.c
@@ -0,0 +1,583 @@
+/* _bz2 - Low-level Python interface to libbzip2. */
+
+#define PY_SSIZE_T_CLEAN
+
+#include "Python.h"
+#include "structmember.h"
+
+#ifdef WITH_THREAD
+#include "pythread.h"
+#endif
+
+#include <bzlib.h>
+#include <stdio.h>
+
+
+#ifndef BZ_CONFIG_ERROR
+#define BZ2_bzCompress bzCompress
+#define BZ2_bzCompressInit bzCompressInit
+#define BZ2_bzCompressEnd bzCompressEnd
+#define BZ2_bzDecompress bzDecompress
+#define BZ2_bzDecompressInit bzDecompressInit
+#define BZ2_bzDecompressEnd bzDecompressEnd
+#endif  /* ! BZ_CONFIG_ERROR */
+
+
+#ifdef WITH_THREAD
+#define ACQUIRE_LOCK(obj) do { \
+    if (!PyThread_acquire_lock((obj)->lock, 0)) { \
+        Py_BEGIN_ALLOW_THREADS \
+        PyThread_acquire_lock((obj)->lock, 1); \
+        Py_END_ALLOW_THREADS \
+    } } while (0)
+#define RELEASE_LOCK(obj) PyThread_release_lock((obj)->lock)
+#else
+#define ACQUIRE_LOCK(obj)
+#define RELEASE_LOCK(obj)
+#endif
+
+
+typedef struct {
+    PyObject_HEAD
+    bz_stream bzs;
+    int flushed;
+#ifdef WITH_THREAD
+    PyThread_type_lock lock;
+#endif
+} BZ2Compressor;
+
+typedef struct {
+    PyObject_HEAD
+    bz_stream bzs;
+    char eof;           /* T_BOOL expects a char */
+    PyObject *unused_data;
+#ifdef WITH_THREAD
+    PyThread_type_lock lock;
+#endif
+} BZ2Decompressor;
+
+
+/* Helper functions. */
+
+static int
+catch_bz2_error(int bzerror)
+{
+    switch(bzerror) {
+        case BZ_OK:
+        case BZ_RUN_OK:
+        case BZ_FLUSH_OK:
+        case BZ_FINISH_OK:
+        case BZ_STREAM_END:
+            return 0;
+
+#ifdef BZ_CONFIG_ERROR
+        case BZ_CONFIG_ERROR:
+            PyErr_SetString(PyExc_SystemError,
+                            "libbzip2 was not compiled correctly");
+            return 1;
+#endif
+        case BZ_PARAM_ERROR:
+            PyErr_SetString(PyExc_ValueError,
+                            "Internal error - "
+                            "invalid parameters passed to libbzip2");
+            return 1;
+        case BZ_MEM_ERROR:
+            PyErr_NoMemory();
+            return 1;
+        case BZ_DATA_ERROR:
+        case BZ_DATA_ERROR_MAGIC:
+            PyErr_SetString(PyExc_IOError, "Invalid data stream");
+            return 1;
+        case BZ_IO_ERROR:
+            PyErr_SetString(PyExc_IOError, "Unknown I/O error");
+            return 1;
+        case BZ_UNEXPECTED_EOF:
+            PyErr_SetString(PyExc_EOFError,
+                            "Compressed file ended before the logical "
+                            "end-of-stream was detected");
+            return 1;
+        case BZ_SEQUENCE_ERROR:
+            PyErr_SetString(PyExc_RuntimeError,
+                            "Internal error - "
+                            "Invalid sequence of commands sent to libbzip2");
+            return 1;
+        default:
+            PyErr_Format(PyExc_IOError,
+                         "Unrecognized error from libbzip2: %d", bzerror);
+            return 1;
+    }
+}
+
+#if BUFSIZ < 8192
+#define SMALLCHUNK 8192
+#else
+#define SMALLCHUNK BUFSIZ
+#endif
+
+#if SIZEOF_INT < 4
+#define BIGCHUNK  (512 * 32)
+#else
+#define BIGCHUNK  (512 * 1024)
+#endif
+
+static int
+grow_buffer(PyObject **buf)
+{
+    size_t size = PyBytes_GET_SIZE(*buf);
+    if (size <= SMALLCHUNK)
+        return _PyBytes_Resize(buf, size + SMALLCHUNK);
+    else if (size <= BIGCHUNK)
+        return _PyBytes_Resize(buf, size * 2);
+    else
+        return _PyBytes_Resize(buf, size + BIGCHUNK);
+}
+
+
+/* BZ2Compressor class. */
+
+static PyObject *
+compress(BZ2Compressor *c, char *data, size_t len, int action)
+{
+    size_t data_size = 0;
+    PyObject *result;
+
+    result = PyBytes_FromStringAndSize(NULL, SMALLCHUNK);
+    if (result == NULL)
+        return NULL;
+    c->bzs.next_in = data;
+    /* FIXME This is not 64-bit clean - avail_in is an int. */
+    c->bzs.avail_in = len;
+    c->bzs.next_out = PyBytes_AS_STRING(result);
+    c->bzs.avail_out = PyBytes_GET_SIZE(result);
+    for (;;) {
+        char *this_out;
+        int bzerror;
+
+        Py_BEGIN_ALLOW_THREADS
+        this_out = c->bzs.next_out;
+        bzerror = BZ2_bzCompress(&c->bzs, action);
+        data_size += c->bzs.next_out - this_out;
+        Py_END_ALLOW_THREADS
+        if (catch_bz2_error(bzerror))
+            goto error;
+
+        /* In regular compression mode, stop when input data is exhausted.
+           In flushing mode, stop when all buffered data has been flushed. */
+        if ((action == BZ_RUN && c->bzs.avail_in == 0) ||
+            (action == BZ_FINISH && bzerror == BZ_STREAM_END))
+            break;
+
+        if (c->bzs.avail_out == 0) {
+            if (grow_buffer(&result) < 0)
+                goto error;
+            c->bzs.next_out = PyBytes_AS_STRING(result) + data_size;
+            c->bzs.avail_out = PyBytes_GET_SIZE(result) - data_size;
+        }
+    }
+    if (data_size != PyBytes_GET_SIZE(result))
+        if (_PyBytes_Resize(&result, data_size) < 0)
+            goto error;
+    return result;
+
+error:
+    Py_XDECREF(result);
+    return NULL;
+}
+
+PyDoc_STRVAR(BZ2Compressor_compress__doc__,
+"compress(data) -> bytes\n"
+"\n"
+"Provide data to the compressor object. Returns a chunk of\n"
+"compressed data if possible, or b'' otherwise.\n"
+"\n"
+"When you have finished providing data to the compressor, call the\n"
+"flush() method to finish the compression process.\n");
+
+static PyObject *
+BZ2Compressor_compress(BZ2Compressor *self, PyObject *args)
+{
+    Py_buffer buffer;
+    PyObject *result = NULL;
+
+    if (!PyArg_ParseTuple(args, "y*:compress", &buffer))
+        return NULL;
+
+    ACQUIRE_LOCK(self);
+    if (self->flushed)
+        PyErr_SetString(PyExc_ValueError, "Compressor has been flushed");
+    else
+        result = compress(self, buffer.buf, buffer.len, BZ_RUN);
+    RELEASE_LOCK(self);
+    PyBuffer_Release(&buffer);
+    return result;
+}
+
+PyDoc_STRVAR(BZ2Compressor_flush__doc__,
+"flush() -> bytes\n"
+"\n"
+"Finish the compression process. Returns the compressed data left\n"
+"in internal buffers.\n"
+"\n"
+"The compressor object may not be used after this method is called.\n");
+
+static PyObject *
+BZ2Compressor_flush(BZ2Compressor *self, PyObject *noargs)
+{
+    PyObject *result = NULL;
+
+    ACQUIRE_LOCK(self);
+    if (self->flushed)
+        PyErr_SetString(PyExc_ValueError, "Repeated call to flush()");
+    else {
+        self->flushed = 1;
+        result = compress(self, NULL, 0, BZ_FINISH);
+    }
+    RELEASE_LOCK(self);
+    return result;
+}
+
+static int
+BZ2Compressor_init(BZ2Compressor *self, PyObject *args, PyObject *kwargs)
+{
+    int compresslevel = 9;
+    int bzerror;
+
+    if (!PyArg_ParseTuple(args, "|i:BZ2Compressor", &compresslevel))
+        return -1;
+    if (!(1 <= compresslevel && compresslevel <= 9)) {
+        PyErr_SetString(PyExc_ValueError,
+                        "compresslevel must be between 1 and 9");
+        return -1;
+    }
+
+#ifdef WITH_THREAD
+    self->lock = PyThread_allocate_lock();
+    if (self->lock == NULL) {
+        PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
+        return -1;
+    }
+#endif
+
+    bzerror = BZ2_bzCompressInit(&self->bzs, compresslevel, 0, 0);
+    if (catch_bz2_error(bzerror))
+        goto error;
+
+    return 0;
+
+error:
+#ifdef WITH_THREAD
+    PyThread_free_lock(self->lock);
+    self->lock = NULL;
+#endif
+    return -1;
+}
+
+static void
+BZ2Compressor_dealloc(BZ2Compressor *self)
+{
+    BZ2_bzCompressEnd(&self->bzs);
+#ifdef WITH_THREAD
+    if (self->lock != NULL)
+        PyThread_free_lock(self->lock);
+#endif
+    Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+static PyMethodDef BZ2Compressor_methods[] = {
+    {"compress", (PyCFunction)BZ2Compressor_compress, METH_VARARGS,
+     BZ2Compressor_compress__doc__},
+    {"flush",    (PyCFunction)BZ2Compressor_flush,    METH_NOARGS,
+     BZ2Compressor_flush__doc__},
+    {NULL}
+};
+
+PyDoc_STRVAR(BZ2Compressor__doc__,
+"BZ2Compressor(compresslevel=9)\n"
+"\n"
+"Create a compressor object for compressing data incrementally.\n"
+"\n"
+"compresslevel, if given, must be a number between 1 and 9.\n"
+"\n"
+"For one-shot compression, use the compress() function instead.\n");
+
+static PyTypeObject BZ2Compressor_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "_bz2.BZ2Compressor",               /* tp_name */
+    sizeof(BZ2Compressor),              /* tp_basicsize */
+    0,                                  /* tp_itemsize */
+    (destructor)BZ2Compressor_dealloc,  /* tp_dealloc */
+    0,                                  /* tp_print */
+    0,                                  /* tp_getattr */
+    0,                                  /* tp_setattr */
+    0,                                  /* tp_reserved */
+    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,                 /* tp_flags */
+    BZ2Compressor__doc__,               /* tp_doc */
+    0,                                  /* tp_traverse */
+    0,                                  /* tp_clear */
+    0,                                  /* tp_richcompare */
+    0,                                  /* tp_weaklistoffset */
+    0,                                  /* tp_iter */
+    0,                                  /* tp_iternext */
+    BZ2Compressor_methods,              /* tp_methods */
+    0,                                  /* tp_members */
+    0,                                  /* tp_getset */
+    0,                                  /* tp_base */
+    0,                                  /* tp_dict */
+    0,                                  /* tp_descr_get */
+    0,                                  /* tp_descr_set */
+    0,                                  /* tp_dictoffset */
+    (initproc)BZ2Compressor_init,       /* tp_init */
+    0,                                  /* tp_alloc */
+    PyType_GenericNew,                  /* tp_new */
+};
+
+
+/* BZ2Decompressor class. */
+
+static PyObject *
+decompress(BZ2Decompressor *d, char *data, size_t len)
+{
+    size_t data_size = 0;
+    PyObject *result;
+
+    result = PyBytes_FromStringAndSize(NULL, SMALLCHUNK);
+    if (result == NULL)
+        return result;
+    d->bzs.next_in = data;
+    /* FIXME This is not 64-bit clean - avail_in is an int. */
+    d->bzs.avail_in = len;
+    d->bzs.next_out = PyBytes_AS_STRING(result);
+    d->bzs.avail_out = PyBytes_GET_SIZE(result);
+    for (;;) {
+        char *this_out;
+        int bzerror;
+
+        Py_BEGIN_ALLOW_THREADS
+        this_out = d->bzs.next_out;
+        bzerror = BZ2_bzDecompress(&d->bzs);
+        data_size += d->bzs.next_out - this_out;
+        Py_END_ALLOW_THREADS
+        if (catch_bz2_error(bzerror))
+            goto error;
+        if (bzerror == BZ_STREAM_END) {
+            d->eof = 1;
+            if (d->bzs.avail_in > 0) { /* Save leftover input to unused_data */
+                Py_CLEAR(d->unused_data);
+                d->unused_data = PyBytes_FromStringAndSize(d->bzs.next_in,
+                                                           d->bzs.avail_in);
+                if (d->unused_data == NULL)
+                    goto error;
+            }
+            break;
+        }
+        if (d->bzs.avail_in == 0)
+            break;
+        if (d->bzs.avail_out == 0) {
+            if (grow_buffer(&result) < 0)
+                goto error;
+            d->bzs.next_out = PyBytes_AS_STRING(result) + data_size;
+            d->bzs.avail_out = PyBytes_GET_SIZE(result) - data_size;
+        }
+    }
+    if (data_size != PyBytes_GET_SIZE(result))
+        if (_PyBytes_Resize(&result, data_size) < 0)
+            goto error;
+    return result;
+
+error:
+    Py_XDECREF(result);
+    return NULL;
+}
+
+PyDoc_STRVAR(BZ2Decompressor_decompress__doc__,
+"decompress(data) -> bytes\n"
+"\n"
+"Provide data to the decompressor object. Returns a chunk of\n"
+"decompressed data if possible, or b'' otherwise.\n"
+"\n"
+"Attempting to decompress data after the end of stream is reached\n"
+"raises an EOFError. Any data found after the end of the stream\n"
+"is ignored and saved in the unused_data attribute.\n");
+
+static PyObject *
+BZ2Decompressor_decompress(BZ2Decompressor *self, PyObject *args)
+{
+    Py_buffer buffer;
+    PyObject *result = NULL;
+
+    if (!PyArg_ParseTuple(args, "y*:decompress", &buffer))
+        return NULL;
+
+    ACQUIRE_LOCK(self);
+    if (self->eof)
+        PyErr_SetString(PyExc_EOFError, "End of stream already reached");
+    else
+        result = decompress(self, buffer.buf, buffer.len);
+    RELEASE_LOCK(self);
+    PyBuffer_Release(&buffer);
+    return result;
+}
+
+static int
+BZ2Decompressor_init(BZ2Decompressor *self, PyObject *args, PyObject *kwargs)
+{
+    int bzerror;
+
+    if (!PyArg_ParseTuple(args, ":BZ2Decompressor"))
+        return -1;
+
+#ifdef WITH_THREAD
+    self->lock = PyThread_allocate_lock();
+    if (self->lock == NULL) {
+        PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
+        return -1;
+    }
+#endif
+
+    self->unused_data = PyBytes_FromStringAndSize("", 0);
+    if (self->unused_data == NULL)
+        goto error;
+
+    bzerror = BZ2_bzDecompressInit(&self->bzs, 0, 0);
+    if (catch_bz2_error(bzerror))
+        goto error;
+
+    return 0;
+
+error:
+    Py_CLEAR(self->unused_data);
+#ifdef WITH_THREAD
+    PyThread_free_lock(self->lock);
+    self->lock = NULL;
+#endif
+    return -1;
+}
+
+static void
+BZ2Decompressor_dealloc(BZ2Decompressor *self)
+{
+    BZ2_bzDecompressEnd(&self->bzs);
+    Py_CLEAR(self->unused_data);
+#ifdef WITH_THREAD
+    if (self->lock != NULL)
+        PyThread_free_lock(self->lock);
+#endif
+    Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+static PyMethodDef BZ2Decompressor_methods[] = {
+    {"decompress", (PyCFunction)BZ2Decompressor_decompress, METH_VARARGS,
+     BZ2Decompressor_decompress__doc__},
+    {NULL}
+};
+
+PyDoc_STRVAR(BZ2Decompressor_eof__doc__,
+"True if the end-of-stream marker has been reached.");
+
+PyDoc_STRVAR(BZ2Decompressor_unused_data__doc__,
+"Data found after the end of the compressed stream.");
+
+static PyMemberDef BZ2Decompressor_members[] = {
+    {"eof", T_BOOL, offsetof(BZ2Decompressor, eof),
+     READONLY, BZ2Decompressor_eof__doc__},
+    {"unused_data", T_OBJECT_EX, offsetof(BZ2Decompressor, unused_data),
+     READONLY, BZ2Decompressor_unused_data__doc__},
+    {NULL}
+};
+
+PyDoc_STRVAR(BZ2Decompressor__doc__,
+"BZ2Decompressor()\n"
+"\n"
+"Create a decompressor object for decompressing data incrementally.\n"
+"\n"
+"For one-shot decompression, use the decompress() function instead.\n");
+
+static PyTypeObject BZ2Decompressor_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "_bz2.BZ2Decompressor",             /* tp_name */
+    sizeof(BZ2Decompressor),            /* tp_basicsize */
+    0,                                  /* tp_itemsize */
+    (destructor)BZ2Decompressor_dealloc,/* tp_dealloc */
+    0,                                  /* tp_print */
+    0,                                  /* tp_getattr */
+    0,                                  /* tp_setattr */
+    0,                                  /* tp_reserved */
+    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,                 /* tp_flags */
+    BZ2Decompressor__doc__,             /* tp_doc */
+    0,                                  /* tp_traverse */
+    0,                                  /* tp_clear */
+    0,                                  /* tp_richcompare */
+    0,                                  /* tp_weaklistoffset */
+    0,                                  /* tp_iter */
+    0,                                  /* tp_iternext */
+    BZ2Decompressor_methods,            /* tp_methods */
+    BZ2Decompressor_members,            /* tp_members */
+    0,                                  /* tp_getset */
+    0,                                  /* tp_base */
+    0,                                  /* tp_dict */
+    0,                                  /* tp_descr_get */
+    0,                                  /* tp_descr_set */
+    0,                                  /* tp_dictoffset */
+    (initproc)BZ2Decompressor_init,     /* tp_init */
+    0,                                  /* tp_alloc */
+    PyType_GenericNew,                  /* tp_new */
+};
+
+
+/* Module initialization. */
+
+static struct PyModuleDef _bz2module = {
+    PyModuleDef_HEAD_INIT,
+    "_bz2",
+    NULL,
+    -1,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC
+PyInit__bz2(void)
+{
+    PyObject *m;
+
+    if (PyType_Ready(&BZ2Compressor_Type) < 0)
+        return NULL;
+    if (PyType_Ready(&BZ2Decompressor_Type) < 0)
+        return NULL;
+
+    m = PyModule_Create(&_bz2module);
+    if (m == NULL)
+        return NULL;
+
+    Py_INCREF(&BZ2Compressor_Type);
+    PyModule_AddObject(m, "BZ2Compressor", (PyObject *)&BZ2Compressor_Type);
+
+    Py_INCREF(&BZ2Decompressor_Type);
+    PyModule_AddObject(m, "BZ2Decompressor",
+                       (PyObject *)&BZ2Decompressor_Type);
+
+    return m;
+}
diff --git a/Modules/bz2module.c b/Modules/bz2module.c
deleted file mode 100644
index 3e55202..0000000
--- a/Modules/bz2module.c
+++ /dev/null
@@ -1,2180 +0,0 @@
-/*
-
-python-bz2 - python bz2 library interface
-
-Copyright (c) 2002  Gustavo Niemeyer <niemeyer@conectiva.com>
-Copyright (c) 2002  Python Software Foundation; All Rights Reserved
-
-*/
-
-#include "Python.h"
-#include <stdio.h>
-#include <bzlib.h>
-#include "structmember.h"
-
-#ifdef WITH_THREAD
-#include "pythread.h"
-#endif
-
-static char __author__[] =
-"The bz2 python module was written by:\n\
-\n\
-    Gustavo Niemeyer <niemeyer@conectiva.com>\n\
-";
-
-/* Our very own off_t-like type, 64-bit if possible */
-/* copied from Objects/fileobject.c */
-#if !defined(HAVE_LARGEFILE_SUPPORT)
-typedef off_t Py_off_t;
-#elif SIZEOF_OFF_T >= 8
-typedef off_t Py_off_t;
-#elif SIZEOF_FPOS_T >= 8
-typedef fpos_t Py_off_t;
-#else
-#error "Large file support, but neither off_t nor fpos_t is large enough."
-#endif
-
-#define BUF(v) PyBytes_AS_STRING(v)
-
-#define MODE_CLOSED   0
-#define MODE_READ     1
-#define MODE_READ_EOF 2
-#define MODE_WRITE    3
-
-#define BZ2FileObject_Check(v)  (Py_TYPE(v) == &BZ2File_Type)
-
-
-#ifdef BZ_CONFIG_ERROR
-
-#if SIZEOF_LONG >= 8
-#define BZS_TOTAL_OUT(bzs) \
-    (((long)bzs->total_out_hi32 << 32) + bzs->total_out_lo32)
-#elif SIZEOF_LONG_LONG >= 8
-#define BZS_TOTAL_OUT(bzs) \
-    (((PY_LONG_LONG)bzs->total_out_hi32 << 32) + bzs->total_out_lo32)
-#else
-#define BZS_TOTAL_OUT(bzs) \
-    bzs->total_out_lo32
-#endif
-
-#else /* ! BZ_CONFIG_ERROR */
-
-#define BZ2_bzRead bzRead
-#define BZ2_bzReadOpen bzReadOpen
-#define BZ2_bzReadClose bzReadClose
-#define BZ2_bzWrite bzWrite
-#define BZ2_bzWriteOpen bzWriteOpen
-#define BZ2_bzWriteClose bzWriteClose
-#define BZ2_bzCompress bzCompress
-#define BZ2_bzCompressInit bzCompressInit
-#define BZ2_bzCompressEnd bzCompressEnd
-#define BZ2_bzDecompress bzDecompress
-#define BZ2_bzDecompressInit bzDecompressInit
-#define BZ2_bzDecompressEnd bzDecompressEnd
-
-#define BZS_TOTAL_OUT(bzs) bzs->total_out
-
-#endif /* ! BZ_CONFIG_ERROR */
-
-
-#ifdef WITH_THREAD
-#define ACQUIRE_LOCK(obj) do { \
-    if (!PyThread_acquire_lock(obj->lock, 0)) { \
-        Py_BEGIN_ALLOW_THREADS \
-        PyThread_acquire_lock(obj->lock, 1); \
-        Py_END_ALLOW_THREADS \
-    } } while(0)
-#define RELEASE_LOCK(obj) PyThread_release_lock(obj->lock)
-#else
-#define ACQUIRE_LOCK(obj)
-#define RELEASE_LOCK(obj)
-#endif
-
-/* Bits in f_newlinetypes */
-#define NEWLINE_UNKNOWN 0       /* No newline seen, yet */
-#define NEWLINE_CR 1            /* \r newline seen */
-#define NEWLINE_LF 2            /* \n newline seen */
-#define NEWLINE_CRLF 4          /* \r\n newline seen */
-
-/* ===================================================================== */
-/* Structure definitions. */
-
-typedef struct {
-    PyObject_HEAD
-    FILE *rawfp;
-
-    char* f_buf;                /* Allocated readahead buffer */
-    char* f_bufend;             /* Points after last occupied position */
-    char* f_bufptr;             /* Current buffer position */
-
-    BZFILE *fp;
-    int mode;
-    Py_off_t pos;
-    Py_off_t size;
-#ifdef WITH_THREAD
-    PyThread_type_lock lock;
-#endif
-} BZ2FileObject;
-
-typedef struct {
-    PyObject_HEAD
-    bz_stream bzs;
-    int running;
-#ifdef WITH_THREAD
-    PyThread_type_lock lock;
-#endif
-} BZ2CompObject;
-
-typedef struct {
-    PyObject_HEAD
-    bz_stream bzs;
-    int running;
-    PyObject *unused_data;
-#ifdef WITH_THREAD
-    PyThread_type_lock lock;
-#endif
-} BZ2DecompObject;
-
-/* ===================================================================== */
-/* Utility functions. */
-
-/* Refuse regular I/O if there's data in the iteration-buffer.
- * Mixing them would cause data to arrive out of order, as the read*
- * methods don't use the iteration buffer. */
-static int
-check_iterbuffered(BZ2FileObject *f)
-{
-    if (f->f_buf != NULL &&
-        (f->f_bufend - f->f_bufptr) > 0 &&
-        f->f_buf[0] != '\0') {
-        PyErr_SetString(PyExc_ValueError,
-            "Mixing iteration and read methods would lose data");
-        return -1;
-    }
-    return 0;
-}
-
-static int
-Util_CatchBZ2Error(int bzerror)
-{
-    int ret = 0;
-    switch(bzerror) {
-        case BZ_OK:
-        case BZ_STREAM_END:
-            break;
-
-#ifdef BZ_CONFIG_ERROR
-        case BZ_CONFIG_ERROR:
-            PyErr_SetString(PyExc_SystemError,
-                            "the bz2 library was not compiled "
-                            "correctly");
-            ret = 1;
-            break;
-#endif
-
-        case BZ_PARAM_ERROR:
-            PyErr_SetString(PyExc_ValueError,
-                            "the bz2 library has received wrong "
-                            "parameters");
-            ret = 1;
-            break;
-
-        case BZ_MEM_ERROR:
-            PyErr_NoMemory();
-            ret = 1;
-            break;
-
-        case BZ_DATA_ERROR:
-        case BZ_DATA_ERROR_MAGIC:
-            PyErr_SetString(PyExc_IOError, "invalid data stream");
-            ret = 1;
-            break;
-
-        case BZ_IO_ERROR:
-            PyErr_SetString(PyExc_IOError, "unknown IO error");
-            ret = 1;
-            break;
-
-        case BZ_UNEXPECTED_EOF:
-            PyErr_SetString(PyExc_EOFError,
-                            "compressed file ended before the "
-                            "logical end-of-stream was detected");
-            ret = 1;
-            break;
-
-        case BZ_SEQUENCE_ERROR:
-            PyErr_SetString(PyExc_RuntimeError,
-                            "wrong sequence of bz2 library "
-                            "commands used");
-            ret = 1;
-            break;
-    }
-    return ret;
-}
-
-#if BUFSIZ < 8192
-#define SMALLCHUNK 8192
-#else
-#define SMALLCHUNK BUFSIZ
-#endif
-
-#if SIZEOF_INT < 4
-#define BIGCHUNK  (512 * 32)
-#else
-#define BIGCHUNK  (512 * 1024)
-#endif
-
-/* This is a hacked version of Python's fileobject.c:new_buffersize(). */
-static size_t
-Util_NewBufferSize(size_t currentsize)
-{
-    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;
-}
-
-/* This is a hacked version of Python's fileobject.c:get_line(). */
-static PyObject *
-Util_GetLine(BZ2FileObject *f, int n)
-{
-    char c;
-    char *buf, *end;
-    size_t total_v_size;        /* total # of slots in buffer */
-    size_t used_v_size;         /* # used slots in buffer */
-    size_t increment;       /* amount to increment the buffer */
-    PyObject *v;
-    int bzerror;
-    int bytes_read;
-
-    total_v_size = n > 0 ? n : 100;
-    v = PyBytes_FromStringAndSize((char *)NULL, total_v_size);
-    if (v == NULL)
-        return NULL;
-
-    buf = BUF(v);
-    end = buf + total_v_size;
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        do {
-            bytes_read = BZ2_bzRead(&bzerror, f->fp, &c, 1);
-            f->pos++;
-            if (bytes_read == 0)
-                break;
-            *buf++ = c;
-        } while (bzerror == BZ_OK && c != '\n' && buf != end);
-        Py_END_ALLOW_THREADS
-        if (bzerror == BZ_STREAM_END) {
-            f->size = f->pos;
-            f->mode = MODE_READ_EOF;
-            break;
-        } else if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-            Py_DECREF(v);
-            return NULL;
-        }
-        if (c == '\n')
-            break;
-        /* Must be because buf == end */
-        if (n > 0)
-            break;
-        used_v_size = total_v_size;
-        increment = total_v_size >> 2; /* mild exponential growth */
-        total_v_size += increment;
-        if (total_v_size > INT_MAX) {
-            PyErr_SetString(PyExc_OverflowError,
-                "line is longer than a Python string can hold");
-            Py_DECREF(v);
-            return NULL;
-        }
-        if (_PyBytes_Resize(&v, total_v_size) < 0) {
-            return NULL;
-        }
-        buf = BUF(v) + used_v_size;
-        end = BUF(v) + total_v_size;
-    }
-
-    used_v_size = buf - BUF(v);
-    if (used_v_size != total_v_size) {
-        if (_PyBytes_Resize(&v, used_v_size) < 0) {
-            v = NULL;
-        }
-    }
-    return v;
-}
-
-/* This is a hacked version of Python's fileobject.c:drop_readahead(). */
-static void
-Util_DropReadAhead(BZ2FileObject *f)
-{
-    if (f->f_buf != NULL) {
-        PyMem_Free(f->f_buf);
-        f->f_buf = NULL;
-    }
-}
-
-/* This is a hacked version of Python's fileobject.c:readahead(). */
-static int
-Util_ReadAhead(BZ2FileObject *f, int bufsize)
-{
-    int chunksize;
-    int bzerror;
-
-    if (f->f_buf != NULL) {
-        if((f->f_bufend - f->f_bufptr) >= 1)
-            return 0;
-        else
-            Util_DropReadAhead(f);
-    }
-    if (f->mode == MODE_READ_EOF) {
-        f->f_bufptr = f->f_buf;
-        f->f_bufend = f->f_buf;
-        return 0;
-    }
-    if ((f->f_buf = PyMem_Malloc(bufsize)) == NULL) {
-        PyErr_NoMemory();
-        return -1;
-    }
-    Py_BEGIN_ALLOW_THREADS
-    chunksize = BZ2_bzRead(&bzerror, f->fp, f->f_buf, bufsize);
-    Py_END_ALLOW_THREADS
-    f->pos += chunksize;
-    if (bzerror == BZ_STREAM_END) {
-        f->size = f->pos;
-        f->mode = MODE_READ_EOF;
-    } else if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        Util_DropReadAhead(f);
-        return -1;
-    }
-    f->f_bufptr = f->f_buf;
-    f->f_bufend = f->f_buf + chunksize;
-    return 0;
-}
-
-/* This is a hacked version of Python's
- * fileobject.c:readahead_get_line_skip(). */
-static PyBytesObject *
-Util_ReadAheadGetLineSkip(BZ2FileObject *f, int skip, int bufsize)
-{
-    PyBytesObject* s;
-    char *bufptr;
-    char *buf;
-    int len;
-
-    if (f->f_buf == NULL)
-        if (Util_ReadAhead(f, bufsize) < 0)
-            return NULL;
-
-    len = f->f_bufend - f->f_bufptr;
-    if (len == 0)
-        return (PyBytesObject *)
-            PyBytes_FromStringAndSize(NULL, skip);
-    bufptr = memchr(f->f_bufptr, '\n', len);
-    if (bufptr != NULL) {
-        bufptr++;                               /* Count the '\n' */
-        len = bufptr - f->f_bufptr;
-        s = (PyBytesObject *)
-            PyBytes_FromStringAndSize(NULL, skip+len);
-        if (s == NULL)
-            return NULL;
-        memcpy(PyBytes_AS_STRING(s)+skip, f->f_bufptr, len);
-        f->f_bufptr = bufptr;
-        if (bufptr == f->f_bufend)
-            Util_DropReadAhead(f);
-    } else {
-        bufptr = f->f_bufptr;
-        buf = f->f_buf;
-        f->f_buf = NULL;                /* Force new readahead buffer */
-        s = Util_ReadAheadGetLineSkip(f, skip+len,
-                                      bufsize + (bufsize>>2));
-        if (s == NULL) {
-            PyMem_Free(buf);
-            return NULL;
-        }
-        memcpy(PyBytes_AS_STRING(s)+skip, bufptr, len);
-        PyMem_Free(buf);
-    }
-    return s;
-}
-
-/* ===================================================================== */
-/* Methods of BZ2File. */
-
-PyDoc_STRVAR(BZ2File_read__doc__,
-"read([size]) -> string\n\
-\n\
-Read at most size uncompressed bytes, returned as a string. If the size\n\
-argument is negative or omitted, read until EOF is reached.\n\
-");
-
-/* This is a hacked version of Python's fileobject.c:file_read(). */
-static PyObject *
-BZ2File_read(BZ2FileObject *self, PyObject *args)
-{
-    long bytesrequested = -1;
-    size_t bytesread, buffersize, chunksize;
-    int bzerror;
-    PyObject *ret = NULL;
-
-    if (!PyArg_ParseTuple(args, "|l:read", &bytesrequested))
-        return NULL;
-
-    ACQUIRE_LOCK(self);
-    switch (self->mode) {
-        case MODE_READ:
-            break;
-        case MODE_READ_EOF:
-            ret = PyBytes_FromStringAndSize("", 0);
-            goto cleanup;
-        case MODE_CLOSED:
-            PyErr_SetString(PyExc_ValueError,
-                            "I/O operation on closed file");
-            goto cleanup;
-        default:
-            PyErr_SetString(PyExc_IOError,
-                            "file is not ready for reading");
-            goto cleanup;
-    }
-
-    /* refuse to mix with f.next() */
-    if (check_iterbuffered(self))
-        goto cleanup;
-
-    if (bytesrequested < 0)
-        buffersize = Util_NewBufferSize((size_t)0);
-    else
-        buffersize = bytesrequested;
-    if (buffersize > INT_MAX) {
-        PyErr_SetString(PyExc_OverflowError,
-                        "requested number of bytes is "
-                        "more than a Python string can hold");
-        goto cleanup;
-    }
-    ret = PyBytes_FromStringAndSize((char *)NULL, buffersize);
-    if (ret == NULL || buffersize == 0)
-        goto cleanup;
-    bytesread = 0;
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        chunksize = BZ2_bzRead(&bzerror, self->fp,
-                               BUF(ret)+bytesread,
-                               buffersize-bytesread);
-        self->pos += chunksize;
-        Py_END_ALLOW_THREADS
-        bytesread += chunksize;
-        if (bzerror == BZ_STREAM_END) {
-            self->size = self->pos;
-            self->mode = MODE_READ_EOF;
-            break;
-        } else if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-            Py_DECREF(ret);
-            ret = NULL;
-            goto cleanup;
-        }
-        if (bytesrequested < 0) {
-            buffersize = Util_NewBufferSize(buffersize);
-            if (_PyBytes_Resize(&ret, buffersize) < 0) {
-                ret = NULL;
-                goto cleanup;
-            }
-        } else {
-            break;
-        }
-    }
-    if (bytesread != buffersize) {
-        if (_PyBytes_Resize(&ret, bytesread) < 0) {
-            ret = NULL;
-        }
-    }
-
-cleanup:
-    RELEASE_LOCK(self);
-    return ret;
-}
-
-PyDoc_STRVAR(BZ2File_readline__doc__,
-"readline([size]) -> string\n\
-\n\
-Return the next line from the file, as a string, retaining newline.\n\
-A non-negative size argument will limit the maximum number of bytes to\n\
-return (an incomplete line may be returned then). Return an empty\n\
-string at EOF.\n\
-");
-
-static PyObject *
-BZ2File_readline(BZ2FileObject *self, PyObject *args)
-{
-    PyObject *ret = NULL;
-    int sizehint = -1;
-
-    if (!PyArg_ParseTuple(args, "|i:readline", &sizehint))
-        return NULL;
-
-    ACQUIRE_LOCK(self);
-    switch (self->mode) {
-        case MODE_READ:
-            break;
-        case MODE_READ_EOF:
-            ret = PyBytes_FromStringAndSize("", 0);
-            goto cleanup;
-        case MODE_CLOSED:
-            PyErr_SetString(PyExc_ValueError,
-                            "I/O operation on closed file");
-            goto cleanup;
-        default:
-            PyErr_SetString(PyExc_IOError,
-                            "file is not ready for reading");
-            goto cleanup;
-    }
-
-    /* refuse to mix with f.next() */
-    if (check_iterbuffered(self))
-        goto cleanup;
-
-    if (sizehint == 0)
-        ret = PyBytes_FromStringAndSize("", 0);
-    else
-        ret = Util_GetLine(self, (sizehint < 0) ? 0 : sizehint);
-
-cleanup:
-    RELEASE_LOCK(self);
-    return ret;
-}
-
-PyDoc_STRVAR(BZ2File_readlines__doc__,
-"readlines([size]) -> list\n\
-\n\
-Call readline() repeatedly and return a list of lines read.\n\
-The optional size argument, if given, is an approximate bound on the\n\
-total number of bytes in the lines returned.\n\
-");
-
-/* This is a hacked version of Python's fileobject.c:file_readlines(). */
-static PyObject *
-BZ2File_readlines(BZ2FileObject *self, PyObject *args)
-{
-    long sizehint = 0;
-    PyObject *list = NULL;
-    PyObject *line;
-    char small_buffer[SMALLCHUNK];
-    char *buffer = small_buffer;
-    size_t buffersize = SMALLCHUNK;
-    PyObject *big_buffer = NULL;
-    size_t nfilled = 0;
-    size_t nread;
-    size_t totalread = 0;
-    char *p, *q, *end;
-    int err;
-    int shortread = 0;
-    int bzerror;
-
-    if (!PyArg_ParseTuple(args, "|l:readlines", &sizehint))
-        return NULL;
-
-    ACQUIRE_LOCK(self);
-    switch (self->mode) {
-        case MODE_READ:
-            break;
-        case MODE_READ_EOF:
-            list = PyList_New(0);
-            goto cleanup;
-        case MODE_CLOSED:
-            PyErr_SetString(PyExc_ValueError,
-                            "I/O operation on closed file");
-            goto cleanup;
-        default:
-            PyErr_SetString(PyExc_IOError,
-                            "file is not ready for reading");
-            goto cleanup;
-    }
-
-    /* refuse to mix with f.next() */
-    if (check_iterbuffered(self))
-        goto cleanup;
-
-    if ((list = PyList_New(0)) == NULL)
-        goto cleanup;
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        nread = BZ2_bzRead(&bzerror, self->fp,
-                           buffer+nfilled, buffersize-nfilled);
-        self->pos += nread;
-        Py_END_ALLOW_THREADS
-        if (bzerror == BZ_STREAM_END) {
-            self->size = self->pos;
-            self->mode = MODE_READ_EOF;
-            if (nread == 0) {
-                sizehint = 0;
-                break;
-            }
-            shortread = 1;
-        } else if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-          error:
-            Py_DECREF(list);
-            list = NULL;
-            goto cleanup;
-        }
-        totalread += nread;
-        p = memchr(buffer+nfilled, '\n', nread);
-        if (!shortread && p == NULL) {
-            /* Need a larger buffer to fit this line */
-            nfilled += nread;
-            buffersize *= 2;
-            if (buffersize > INT_MAX) {
-                PyErr_SetString(PyExc_OverflowError,
-                "line is longer than a Python string can hold");
-                goto error;
-            }
-            if (big_buffer == NULL) {
-                /* Create the big buffer */
-                big_buffer = PyBytes_FromStringAndSize(
-                    NULL, buffersize);
-                if (big_buffer == NULL)
-                    goto error;
-                buffer = PyBytes_AS_STRING(big_buffer);
-                memcpy(buffer, small_buffer, nfilled);
-            }
-            else {
-                /* Grow the big buffer */
-                if (_PyBytes_Resize(&big_buffer, buffersize) < 0){
-                    big_buffer = NULL;
-                    goto error;
-                }
-                buffer = PyBytes_AS_STRING(big_buffer);
-            }
-            continue;
-        }
-        end = buffer+nfilled+nread;
-        q = buffer;
-        while (p != NULL) {
-            /* Process complete lines */
-            p++;
-            line = PyBytes_FromStringAndSize(q, p-q);
-            if (line == NULL)
-                goto error;
-            err = PyList_Append(list, line);
-            Py_DECREF(line);
-            if (err != 0)
-                goto error;
-            q = p;
-            p = memchr(q, '\n', end-q);
-        }
-        /* Move the remaining incomplete line to the start */
-        nfilled = end-q;
-        memmove(buffer, q, nfilled);
-        if (sizehint > 0)
-            if (totalread >= (size_t)sizehint)
-                break;
-        if (shortread) {
-            sizehint = 0;
-            break;
-        }
-    }
-    if (nfilled != 0) {
-        /* Partial last line */
-        line = PyBytes_FromStringAndSize(buffer, nfilled);
-        if (line == NULL)
-            goto error;
-        if (sizehint > 0) {
-            /* Need to complete the last line */
-            PyObject *rest = Util_GetLine(self, 0);
-            if (rest == NULL) {
-                Py_DECREF(line);
-                goto error;
-            }
-            PyBytes_Concat(&line, rest);
-            Py_DECREF(rest);
-            if (line == NULL)
-                goto error;
-        }
-        err = PyList_Append(list, line);
-        Py_DECREF(line);
-        if (err != 0)
-            goto error;
-    }
-
-  cleanup:
-    RELEASE_LOCK(self);
-    if (big_buffer) {
-        Py_DECREF(big_buffer);
-    }
-    return list;
-}
-
-PyDoc_STRVAR(BZ2File_write__doc__,
-"write(data) -> None\n\
-\n\
-Write the 'data' string to file. Note that due to buffering, close() may\n\
-be needed before the file on disk reflects the data written.\n\
-");
-
-/* This is a hacked version of Python's fileobject.c:file_write(). */
-static PyObject *
-BZ2File_write(BZ2FileObject *self, PyObject *args)
-{
-    PyObject *ret = NULL;
-    Py_buffer pbuf;
-    char *buf;
-    int len;
-    int bzerror;
-
-    if (!PyArg_ParseTuple(args, "y*:write", &pbuf))
-        return NULL;
-    buf = pbuf.buf;
-    len = pbuf.len;
-
-    ACQUIRE_LOCK(self);
-    switch (self->mode) {
-        case MODE_WRITE:
-            break;
-
-        case MODE_CLOSED:
-            PyErr_SetString(PyExc_ValueError,
-                            "I/O operation on closed file");
-            goto cleanup;
-
-        default:
-            PyErr_SetString(PyExc_IOError,
-                            "file is not ready for writing");
-            goto cleanup;
-    }
-
-    Py_BEGIN_ALLOW_THREADS
-    BZ2_bzWrite (&bzerror, self->fp, buf, len);
-    self->pos += len;
-    Py_END_ALLOW_THREADS
-
-    if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        goto cleanup;
-    }
-
-    Py_INCREF(Py_None);
-    ret = Py_None;
-
-cleanup:
-    PyBuffer_Release(&pbuf);
-    RELEASE_LOCK(self);
-    return ret;
-}
-
-PyDoc_STRVAR(BZ2File_writelines__doc__,
-"writelines(sequence_of_strings) -> None\n\
-\n\
-Write the sequence of strings to the file. Note that newlines are not\n\
-added. The sequence can be any iterable object producing strings. This is\n\
-equivalent to calling write() for each string.\n\
-");
-
-/* This is a hacked version of Python's fileobject.c:file_writelines(). */
-static PyObject *
-BZ2File_writelines(BZ2FileObject *self, PyObject *seq)
-{
-#define CHUNKSIZE 1000
-    PyObject *list = NULL;
-    PyObject *iter = NULL;
-    PyObject *ret = NULL;
-    PyObject *line;
-    int i, j, index, len, islist;
-    int bzerror;
-
-    ACQUIRE_LOCK(self);
-    switch (self->mode) {
-        case MODE_WRITE:
-            break;
-
-        case MODE_CLOSED:
-            PyErr_SetString(PyExc_ValueError,
-                            "I/O operation on closed file");
-            goto error;
-
-        default:
-            PyErr_SetString(PyExc_IOError,
-                            "file is not ready for writing");
-            goto error;
-    }
-
-    islist = PyList_Check(seq);
-    if  (!islist) {
-        iter = PyObject_GetIter(seq);
-        if (iter == NULL) {
-            PyErr_SetString(PyExc_TypeError,
-                "writelines() requires an iterable argument");
-            goto error;
-        }
-        list = PyList_New(CHUNKSIZE);
-        if (list == NULL)
-            goto error;
-    }
-
-    /* Strategy: slurp CHUNKSIZE lines into a private list,
-       checking that they are all strings, then write that list
-       without holding the interpreter lock, then come back for more. */
-    for (index = 0; ; index += CHUNKSIZE) {
-        if (islist) {
-            Py_XDECREF(list);
-            list = PyList_GetSlice(seq, index, index+CHUNKSIZE);
-            if (list == NULL)
-                goto error;
-            j = PyList_GET_SIZE(list);
-        }
-        else {
-            for (j = 0; j < CHUNKSIZE; j++) {
-                line = PyIter_Next(iter);
-                if (line == NULL) {
-                    if (PyErr_Occurred())
-                        goto error;
-                    break;
-                }
-                PyList_SetItem(list, j, line);
-            }
-        }
-        if (j == 0)
-            break;
-
-        /* Check that all entries are indeed byte strings. If not,
-           apply the same rules as for file.write() and
-           convert the rets to strings. This is slow, but
-           seems to be the only way since all conversion APIs
-           could potentially execute Python code. */
-        for (i = 0; i < j; i++) {
-            PyObject *v = PyList_GET_ITEM(list, i);
-            if (!PyBytes_Check(v)) {
-                const char *buffer;
-                Py_ssize_t len;
-                if (PyObject_AsCharBuffer(v, &buffer, &len)) {
-                    PyErr_SetString(PyExc_TypeError,
-                                    "writelines() "
-                                    "argument must be "
-                                    "a sequence of "
-                                    "bytes objects");
-                    goto error;
-                }
-                line = PyBytes_FromStringAndSize(buffer,
-                                                  len);
-                if (line == NULL)
-                    goto error;
-                Py_DECREF(v);
-                PyList_SET_ITEM(list, i, line);
-            }
-        }
-
-        /* Since we are releasing the global lock, the
-           following code may *not* execute Python code. */
-        Py_BEGIN_ALLOW_THREADS
-        for (i = 0; i < j; i++) {
-            line = PyList_GET_ITEM(list, i);
-            len = PyBytes_GET_SIZE(line);
-            BZ2_bzWrite (&bzerror, self->fp,
-                         PyBytes_AS_STRING(line), len);
-            if (bzerror != BZ_OK) {
-                Py_BLOCK_THREADS
-                Util_CatchBZ2Error(bzerror);
-                goto error;
-            }
-        }
-        Py_END_ALLOW_THREADS
-
-        if (j < CHUNKSIZE)
-            break;
-    }
-
-    Py_INCREF(Py_None);
-    ret = Py_None;
-
-  error:
-    RELEASE_LOCK(self);
-    Py_XDECREF(list);
-    Py_XDECREF(iter);
-    return ret;
-#undef CHUNKSIZE
-}
-
-PyDoc_STRVAR(BZ2File_seek__doc__,
-"seek(offset [, whence]) -> None\n\
-\n\
-Move to new file position. Argument offset is a byte count. Optional\n\
-argument whence defaults to 0 (offset from start of file, offset\n\
-should be >= 0); other values are 1 (move relative to current position,\n\
-positive or negative), and 2 (move relative to end of file, usually\n\
-negative, although many platforms allow seeking beyond the end of a file).\n\
-\n\
-Note that seeking of bz2 files is emulated, and depending on the parameters\n\
-the operation may be extremely slow.\n\
-");
-
-static PyObject *
-BZ2File_seek(BZ2FileObject *self, PyObject *args)
-{
-    int where = 0;
-    PyObject *offobj;
-    Py_off_t offset;
-    char small_buffer[SMALLCHUNK];
-    char *buffer = small_buffer;
-    size_t buffersize = SMALLCHUNK;
-    Py_off_t bytesread = 0;
-    size_t readsize;
-    int chunksize;
-    int bzerror;
-    PyObject *ret = NULL;
-
-    if (!PyArg_ParseTuple(args, "O|i:seek", &offobj, &where))
-        return NULL;
-#if !defined(HAVE_LARGEFILE_SUPPORT)
-    offset = PyLong_AsLong(offobj);
-#else
-    offset = PyLong_Check(offobj) ?
-        PyLong_AsLongLong(offobj) : PyLong_AsLong(offobj);
-#endif
-    if (PyErr_Occurred())
-        return NULL;
-
-    ACQUIRE_LOCK(self);
-    Util_DropReadAhead(self);
-    switch (self->mode) {
-        case MODE_READ:
-        case MODE_READ_EOF:
-            break;
-
-        case MODE_CLOSED:
-            PyErr_SetString(PyExc_ValueError,
-                            "I/O operation on closed file");
-            goto cleanup;
-
-        default:
-            PyErr_SetString(PyExc_IOError,
-                            "seek works only while reading");
-            goto cleanup;
-    }
-
-    if (where == 2) {
-        if (self->size == -1) {
-            assert(self->mode != MODE_READ_EOF);
-            for (;;) {
-                Py_BEGIN_ALLOW_THREADS
-                chunksize = BZ2_bzRead(&bzerror, self->fp,
-                                       buffer, buffersize);
-                self->pos += chunksize;
-                Py_END_ALLOW_THREADS
-
-                bytesread += chunksize;
-                if (bzerror == BZ_STREAM_END) {
-                    break;
-                } else if (bzerror != BZ_OK) {
-                    Util_CatchBZ2Error(bzerror);
-                    goto cleanup;
-                }
-            }
-            self->mode = MODE_READ_EOF;
-            self->size = self->pos;
-            bytesread = 0;
-        }
-        offset = self->size + offset;
-    } else if (where == 1) {
-        offset = self->pos + offset;
-    }
-
-    /* Before getting here, offset must be the absolute position the file
-     * pointer should be set to. */
-
-    if (offset >= self->pos) {
-        /* we can move forward */
-        offset -= self->pos;
-    } else {
-        /* we cannot move back, so rewind the stream */
-        BZ2_bzReadClose(&bzerror, self->fp);
-        if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-            goto cleanup;
-        }
-        rewind(self->rawfp);
-        self->pos = 0;
-        self->fp = BZ2_bzReadOpen(&bzerror, self->rawfp,
-                                  0, 0, NULL, 0);
-        if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-            goto cleanup;
-        }
-        self->mode = MODE_READ;
-    }
-
-    if (offset <= 0 || self->mode == MODE_READ_EOF)
-        goto exit;
-
-    /* Before getting here, offset must be set to the number of bytes
-     * to walk forward. */
-    for (;;) {
-        if (offset-bytesread > buffersize)
-            readsize = buffersize;
-        else
-            /* offset might be wider that readsize, but the result
-             * of the subtraction is bound by buffersize (see the
-             * condition above). buffersize is 8192. */
-            readsize = (size_t)(offset-bytesread);
-        Py_BEGIN_ALLOW_THREADS
-        chunksize = BZ2_bzRead(&bzerror, self->fp, buffer, readsize);
-        self->pos += chunksize;
-        Py_END_ALLOW_THREADS
-        bytesread += chunksize;
-        if (bzerror == BZ_STREAM_END) {
-            self->size = self->pos;
-            self->mode = MODE_READ_EOF;
-            break;
-        } else if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-            goto cleanup;
-        }
-        if (bytesread == offset)
-            break;
-    }
-
-exit:
-    Py_INCREF(Py_None);
-    ret = Py_None;
-
-cleanup:
-    RELEASE_LOCK(self);
-    return ret;
-}
-
-PyDoc_STRVAR(BZ2File_tell__doc__,
-"tell() -> int\n\
-\n\
-Return the current file position, an integer (may be a long integer).\n\
-");
-
-static PyObject *
-BZ2File_tell(BZ2FileObject *self, PyObject *args)
-{
-    PyObject *ret = NULL;
-
-    if (self->mode == MODE_CLOSED) {
-        PyErr_SetString(PyExc_ValueError,
-                        "I/O operation on closed file");
-        goto cleanup;
-    }
-
-#if !defined(HAVE_LARGEFILE_SUPPORT)
-    ret = PyLong_FromLong(self->pos);
-#else
-    ret = PyLong_FromLongLong(self->pos);
-#endif
-
-cleanup:
-    return ret;
-}
-
-PyDoc_STRVAR(BZ2File_close__doc__,
-"close() -> None or (perhaps) an integer\n\
-\n\
-Close the file. Sets data attribute .closed to true. A closed file\n\
-cannot be used for further I/O operations. close() may be called more\n\
-than once without error.\n\
-");
-
-static PyObject *
-BZ2File_close(BZ2FileObject *self)
-{
-    PyObject *ret = NULL;
-    int bzerror = BZ_OK;
-
-    if (self->mode == MODE_CLOSED) {
-        Py_RETURN_NONE;
-    }
-
-    ACQUIRE_LOCK(self);
-    switch (self->mode) {
-        case MODE_READ:
-        case MODE_READ_EOF:
-            BZ2_bzReadClose(&bzerror, self->fp);
-            break;
-        case MODE_WRITE:
-            BZ2_bzWriteClose(&bzerror, self->fp,
-                             0, NULL, NULL);
-            break;
-    }
-    self->mode = MODE_CLOSED;
-    fclose(self->rawfp);
-    self->rawfp = NULL;
-    if (bzerror == BZ_OK) {
-        Py_INCREF(Py_None);
-        ret = Py_None;
-    }
-    else {
-        Util_CatchBZ2Error(bzerror);
-    }
-
-    RELEASE_LOCK(self);
-    return ret;
-}
-
-PyDoc_STRVAR(BZ2File_enter_doc,
-"__enter__() -> self.");
-
-static PyObject *
-BZ2File_enter(BZ2FileObject *self)
-{
-    if (self->mode == MODE_CLOSED) {
-        PyErr_SetString(PyExc_ValueError,
-            "I/O operation on closed file");
-        return NULL;
-    }
-    Py_INCREF(self);
-    return (PyObject *) self;
-}
-
-PyDoc_STRVAR(BZ2File_exit_doc,
-"__exit__(*excinfo) -> None.  Closes the file.");
-
-static PyObject *
-BZ2File_exit(BZ2FileObject *self, PyObject *args)
-{
-    PyObject *ret = PyObject_CallMethod((PyObject *) self, "close", NULL);
-    if (!ret)
-        /* If error occurred, pass through */
-        return NULL;
-    Py_DECREF(ret);
-    Py_RETURN_NONE;
-}
-
-
-static PyObject *BZ2File_getiter(BZ2FileObject *self);
-
-static PyMethodDef BZ2File_methods[] = {
-    {"read", (PyCFunction)BZ2File_read, METH_VARARGS, BZ2File_read__doc__},
-    {"readline", (PyCFunction)BZ2File_readline, METH_VARARGS, BZ2File_readline__doc__},
-    {"readlines", (PyCFunction)BZ2File_readlines, METH_VARARGS, BZ2File_readlines__doc__},
-    {"write", (PyCFunction)BZ2File_write, METH_VARARGS, BZ2File_write__doc__},
-    {"writelines", (PyCFunction)BZ2File_writelines, METH_O, BZ2File_writelines__doc__},
-    {"seek", (PyCFunction)BZ2File_seek, METH_VARARGS, BZ2File_seek__doc__},
-    {"tell", (PyCFunction)BZ2File_tell, METH_NOARGS, BZ2File_tell__doc__},
-    {"close", (PyCFunction)BZ2File_close, METH_NOARGS, BZ2File_close__doc__},
-    {"__enter__", (PyCFunction)BZ2File_enter, METH_NOARGS, BZ2File_enter_doc},
-    {"__exit__", (PyCFunction)BZ2File_exit, METH_VARARGS, BZ2File_exit_doc},
-    {NULL,              NULL}           /* sentinel */
-};
-
-
-/* ===================================================================== */
-/* Getters and setters of BZ2File. */
-
-static PyObject *
-BZ2File_get_closed(BZ2FileObject *self, void *closure)
-{
-    return PyLong_FromLong(self->mode == MODE_CLOSED);
-}
-
-static PyGetSetDef BZ2File_getset[] = {
-    {"closed", (getter)BZ2File_get_closed, NULL,
-                    "True if the file is closed"},
-    {NULL}      /* Sentinel */
-};
-
-
-/* ===================================================================== */
-/* Slot definitions for BZ2File_Type. */
-
-static int
-BZ2File_init(BZ2FileObject *self, PyObject *args, PyObject *kwargs)
-{
-    static char *kwlist[] = {"filename", "mode", "buffering",
-                             "compresslevel", 0};
-    PyObject *name_obj = NULL;
-    char *name;
-    char *mode = "r";
-    int buffering = -1;
-    int compresslevel = 9;
-    int bzerror;
-    int mode_char = 0;
-
-    self->size = -1;
-
-    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O&|sii:BZ2File",
-                                     kwlist, PyUnicode_FSConverter, &name_obj,
-                                     &mode, &buffering,
-                                     &compresslevel))
-        return -1;
-
-    name = PyBytes_AsString(name_obj);
-    if (compresslevel < 1 || compresslevel > 9) {
-        PyErr_SetString(PyExc_ValueError,
-                        "compresslevel must be between 1 and 9");
-        Py_DECREF(name_obj);
-        return -1;
-    }
-
-    for (;;) {
-        int error = 0;
-        switch (*mode) {
-            case 'r':
-            case 'w':
-                if (mode_char)
-                    error = 1;
-                mode_char = *mode;
-                break;
-
-            case 'b':
-                break;
-
-            default:
-                error = 1;
-                break;
-        }
-        if (error) {
-            PyErr_Format(PyExc_ValueError,
-                         "invalid mode char %c", *mode);
-            Py_DECREF(name_obj);
-            return -1;
-        }
-        mode++;
-        if (*mode == '\0')
-            break;
-    }
-
-    if (mode_char == 0) {
-        mode_char = 'r';
-    }
-
-    mode = (mode_char == 'r') ? "rb" : "wb";
-
-    self->rawfp = fopen(name, mode);
-    Py_DECREF(name_obj);
-    if (self->rawfp == NULL) {
-        PyErr_SetFromErrno(PyExc_IOError);
-        return -1;
-    }
-    /* XXX Ignore buffering */
-
-    /* From now on, we have stuff to dealloc, so jump to error label
-     * instead of returning */
-
-#ifdef WITH_THREAD
-    self->lock = PyThread_allocate_lock();
-    if (!self->lock) {
-        PyErr_SetString(PyExc_MemoryError, "unable to allocate lock");
-        goto error;
-    }
-#endif
-
-    if (mode_char == 'r')
-        self->fp = BZ2_bzReadOpen(&bzerror, self->rawfp,
-                                  0, 0, NULL, 0);
-    else
-        self->fp = BZ2_bzWriteOpen(&bzerror, self->rawfp,
-                                   compresslevel, 0, 0);
-
-    if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        goto error;
-    }
-
-    self->mode = (mode_char == 'r') ? MODE_READ : MODE_WRITE;
-
-    return 0;
-
-error:
-    fclose(self->rawfp);
-    self->rawfp = NULL;
-#ifdef WITH_THREAD
-    if (self->lock) {
-        PyThread_free_lock(self->lock);
-        self->lock = NULL;
-    }
-#endif
-    return -1;
-}
-
-static void
-BZ2File_dealloc(BZ2FileObject *self)
-{
-    int bzerror;
-#ifdef WITH_THREAD
-    if (self->lock)
-        PyThread_free_lock(self->lock);
-#endif
-    switch (self->mode) {
-        case MODE_READ:
-        case MODE_READ_EOF:
-            BZ2_bzReadClose(&bzerror, self->fp);
-            break;
-        case MODE_WRITE:
-            BZ2_bzWriteClose(&bzerror, self->fp,
-                             0, NULL, NULL);
-            break;
-    }
-    Util_DropReadAhead(self);
-    if (self->rawfp != NULL)
-        fclose(self->rawfp);
-    Py_TYPE(self)->tp_free((PyObject *)self);
-}
-
-/* This is a hacked version of Python's fileobject.c:file_getiter(). */
-static PyObject *
-BZ2File_getiter(BZ2FileObject *self)
-{
-    if (self->mode == MODE_CLOSED) {
-        PyErr_SetString(PyExc_ValueError,
-                        "I/O operation on closed file");
-        return NULL;
-    }
-    Py_INCREF((PyObject*)self);
-    return (PyObject *)self;
-}
-
-/* This is a hacked version of Python's fileobject.c:file_iternext(). */
-#define READAHEAD_BUFSIZE 8192
-static PyObject *
-BZ2File_iternext(BZ2FileObject *self)
-{
-    PyBytesObject* ret;
-    ACQUIRE_LOCK(self);
-    if (self->mode == MODE_CLOSED) {
-        RELEASE_LOCK(self);
-        PyErr_SetString(PyExc_ValueError,
-                        "I/O operation on closed file");
-        return NULL;
-    }
-    ret = Util_ReadAheadGetLineSkip(self, 0, READAHEAD_BUFSIZE);
-    RELEASE_LOCK(self);
-    if (ret == NULL || PyBytes_GET_SIZE(ret) == 0) {
-        Py_XDECREF(ret);
-        return NULL;
-    }
-    return (PyObject *)ret;
-}
-
-/* ===================================================================== */
-/* BZ2File_Type definition. */
-
-PyDoc_VAR(BZ2File__doc__) =
-PyDoc_STR(
-"BZ2File(name [, mode='r', buffering=0, compresslevel=9]) -> file object\n\
-\n\
-Open a bz2 file. The mode can be 'r' or 'w', for reading (default) or\n\
-writing. When opened for writing, the file will be created if it doesn't\n\
-exist, and truncated otherwise. If the buffering argument is given, 0 means\n\
-unbuffered, and larger numbers specify the buffer size. If compresslevel\n\
-is given, must be a number between 1 and 9.\n\
-Data read is always returned in bytes; data written ought to be bytes.\n\
-");
-
-static PyTypeObject BZ2File_Type = {
-    PyVarObject_HEAD_INIT(NULL, 0)
-    "bz2.BZ2File",              /*tp_name*/
-    sizeof(BZ2FileObject),      /*tp_basicsize*/
-    0,                          /*tp_itemsize*/
-    (destructor)BZ2File_dealloc, /*tp_dealloc*/
-    0,                          /*tp_print*/
-    0,                          /*tp_getattr*/
-    0,                          /*tp_setattr*/
-    0,                          /*tp_reserved*/
-    0,                          /*tp_repr*/
-    0,                          /*tp_as_number*/
-    0,                          /*tp_as_sequence*/
-    0,                          /*tp_as_mapping*/
-    0,                          /*tp_hash*/
-    0,                      /*tp_call*/
-    0,                      /*tp_str*/
-    PyObject_GenericGetAttr,/*tp_getattro*/
-    PyObject_GenericSetAttr,/*tp_setattro*/
-    0,                      /*tp_as_buffer*/
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE, /*tp_flags*/
-    BZ2File__doc__,         /*tp_doc*/
-    0,                      /*tp_traverse*/
-    0,                      /*tp_clear*/
-    0,                      /*tp_richcompare*/
-    0,                      /*tp_weaklistoffset*/
-    (getiterfunc)BZ2File_getiter, /*tp_iter*/
-    (iternextfunc)BZ2File_iternext, /*tp_iternext*/
-    BZ2File_methods,        /*tp_methods*/
-    0,                          /*tp_members*/
-    BZ2File_getset,         /*tp_getset*/
-    0,                      /*tp_base*/
-    0,                      /*tp_dict*/
-    0,                      /*tp_descr_get*/
-    0,                      /*tp_descr_set*/
-    0,                      /*tp_dictoffset*/
-    (initproc)BZ2File_init, /*tp_init*/
-    PyType_GenericAlloc,    /*tp_alloc*/
-    PyType_GenericNew,      /*tp_new*/
-    PyObject_Free,          /*tp_free*/
-    0,                      /*tp_is_gc*/
-};
-
-
-/* ===================================================================== */
-/* Methods of BZ2Comp. */
-
-PyDoc_STRVAR(BZ2Comp_compress__doc__,
-"compress(data) -> string\n\
-\n\
-Provide more data to the compressor object. It will return chunks of\n\
-compressed data whenever possible. When you've finished providing data\n\
-to compress, call the flush() method to finish the compression process,\n\
-and return what is left in the internal buffers.\n\
-");
-
-static PyObject *
-BZ2Comp_compress(BZ2CompObject *self, PyObject *args)
-{
-    Py_buffer pdata;
-    char *data;
-    int datasize;
-    int bufsize = SMALLCHUNK;
-    PY_LONG_LONG totalout;
-    PyObject *ret = NULL;
-    bz_stream *bzs = &self->bzs;
-    int bzerror;
-
-    if (!PyArg_ParseTuple(args, "y*:compress", &pdata))
-        return NULL;
-    data = pdata.buf;
-    datasize = pdata.len;
-
-    if (datasize == 0) {
-        PyBuffer_Release(&pdata);
-        return PyBytes_FromStringAndSize("", 0);
-    }
-
-    ACQUIRE_LOCK(self);
-    if (!self->running) {
-        PyErr_SetString(PyExc_ValueError,
-                        "this object was already flushed");
-        goto error;
-    }
-
-    ret = PyBytes_FromStringAndSize(NULL, bufsize);
-    if (!ret)
-        goto error;
-
-    bzs->next_in = data;
-    bzs->avail_in = datasize;
-    bzs->next_out = BUF(ret);
-    bzs->avail_out = bufsize;
-
-    totalout = BZS_TOTAL_OUT(bzs);
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        bzerror = BZ2_bzCompress(bzs, BZ_RUN);
-        Py_END_ALLOW_THREADS
-        if (bzerror != BZ_RUN_OK) {
-            Util_CatchBZ2Error(bzerror);
-            goto error;
-        }
-        if (bzs->avail_in == 0)
-            break; /* no more input data */
-        if (bzs->avail_out == 0) {
-            bufsize = Util_NewBufferSize(bufsize);
-            if (_PyBytes_Resize(&ret, bufsize) < 0) {
-                BZ2_bzCompressEnd(bzs);
-                goto error;
-            }
-            bzs->next_out = BUF(ret) + (BZS_TOTAL_OUT(bzs)
-                                        - totalout);
-            bzs->avail_out = bufsize - (bzs->next_out - BUF(ret));
-        }
-    }
-
-    if (_PyBytes_Resize(&ret,
-                       (Py_ssize_t)(BZS_TOTAL_OUT(bzs) - totalout)) < 0)
-        goto error;
-
-    RELEASE_LOCK(self);
-    PyBuffer_Release(&pdata);
-    return ret;
-
-error:
-    RELEASE_LOCK(self);
-    PyBuffer_Release(&pdata);
-    Py_XDECREF(ret);
-    return NULL;
-}
-
-PyDoc_STRVAR(BZ2Comp_flush__doc__,
-"flush() -> string\n\
-\n\
-Finish the compression process and return what is left in internal buffers.\n\
-You must not use the compressor object after calling this method.\n\
-");
-
-static PyObject *
-BZ2Comp_flush(BZ2CompObject *self)
-{
-    int bufsize = SMALLCHUNK;
-    PyObject *ret = NULL;
-    bz_stream *bzs = &self->bzs;
-    PY_LONG_LONG totalout;
-    int bzerror;
-
-    ACQUIRE_LOCK(self);
-    if (!self->running) {
-        PyErr_SetString(PyExc_ValueError, "object was already "
-                                          "flushed");
-        goto error;
-    }
-    self->running = 0;
-
-    ret = PyBytes_FromStringAndSize(NULL, bufsize);
-    if (!ret)
-        goto error;
-
-    bzs->next_out = BUF(ret);
-    bzs->avail_out = bufsize;
-
-    totalout = BZS_TOTAL_OUT(bzs);
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        bzerror = BZ2_bzCompress(bzs, BZ_FINISH);
-        Py_END_ALLOW_THREADS
-        if (bzerror == BZ_STREAM_END) {
-            break;
-        } else if (bzerror != BZ_FINISH_OK) {
-            Util_CatchBZ2Error(bzerror);
-            goto error;
-        }
-        if (bzs->avail_out == 0) {
-            bufsize = Util_NewBufferSize(bufsize);
-            if (_PyBytes_Resize(&ret, bufsize) < 0)
-                goto error;
-            bzs->next_out = BUF(ret);
-            bzs->next_out = BUF(ret) + (BZS_TOTAL_OUT(bzs)
-                                        - totalout);
-            bzs->avail_out = bufsize - (bzs->next_out - BUF(ret));
-        }
-    }
-
-    if (bzs->avail_out != 0) {
-        if (_PyBytes_Resize(&ret,
-                    (Py_ssize_t)(BZS_TOTAL_OUT(bzs) - totalout)) < 0)
-            goto error;
-    }
-
-    RELEASE_LOCK(self);
-    return ret;
-
-error:
-    RELEASE_LOCK(self);
-    Py_XDECREF(ret);
-    return NULL;
-}
-
-static PyMethodDef BZ2Comp_methods[] = {
-    {"compress", (PyCFunction)BZ2Comp_compress, METH_VARARGS,
-     BZ2Comp_compress__doc__},
-    {"flush", (PyCFunction)BZ2Comp_flush, METH_NOARGS,
-     BZ2Comp_flush__doc__},
-    {NULL,              NULL}           /* sentinel */
-};
-
-
-/* ===================================================================== */
-/* Slot definitions for BZ2Comp_Type. */
-
-static int
-BZ2Comp_init(BZ2CompObject *self, PyObject *args, PyObject *kwargs)
-{
-    int compresslevel = 9;
-    int bzerror;
-    static char *kwlist[] = {"compresslevel", 0};
-
-    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|i:BZ2Compressor",
-                                     kwlist, &compresslevel))
-        return -1;
-
-    if (compresslevel < 1 || compresslevel > 9) {
-        PyErr_SetString(PyExc_ValueError,
-                        "compresslevel must be between 1 and 9");
-        goto error;
-    }
-
-#ifdef WITH_THREAD
-    self->lock = PyThread_allocate_lock();
-    if (!self->lock) {
-        PyErr_SetString(PyExc_MemoryError, "unable to allocate lock");
-        goto error;
-    }
-#endif
-
-    memset(&self->bzs, 0, sizeof(bz_stream));
-    bzerror = BZ2_bzCompressInit(&self->bzs, compresslevel, 0, 0);
-    if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        goto error;
-    }
-
-    self->running = 1;
-
-    return 0;
-error:
-#ifdef WITH_THREAD
-    if (self->lock) {
-        PyThread_free_lock(self->lock);
-        self->lock = NULL;
-    }
-#endif
-    return -1;
-}
-
-static void
-BZ2Comp_dealloc(BZ2CompObject *self)
-{
-#ifdef WITH_THREAD
-    if (self->lock)
-        PyThread_free_lock(self->lock);
-#endif
-    BZ2_bzCompressEnd(&self->bzs);
-    Py_TYPE(self)->tp_free((PyObject *)self);
-}
-
-
-/* ===================================================================== */
-/* BZ2Comp_Type definition. */
-
-PyDoc_STRVAR(BZ2Comp__doc__,
-"BZ2Compressor([compresslevel=9]) -> compressor object\n\
-\n\
-Create a new compressor object. This object may be used to compress\n\
-data sequentially. If you want to compress data in one shot, use the\n\
-compress() function instead. The compresslevel parameter, if given,\n\
-must be a number between 1 and 9.\n\
-");
-
-static PyTypeObject BZ2Comp_Type = {
-    PyVarObject_HEAD_INIT(NULL, 0)
-    "bz2.BZ2Compressor",        /*tp_name*/
-    sizeof(BZ2CompObject),      /*tp_basicsize*/
-    0,                          /*tp_itemsize*/
-    (destructor)BZ2Comp_dealloc, /*tp_dealloc*/
-    0,                          /*tp_print*/
-    0,                          /*tp_getattr*/
-    0,                          /*tp_setattr*/
-    0,                          /*tp_reserved*/
-    0,                          /*tp_repr*/
-    0,                          /*tp_as_number*/
-    0,                          /*tp_as_sequence*/
-    0,                          /*tp_as_mapping*/
-    0,                          /*tp_hash*/
-    0,                      /*tp_call*/
-    0,                      /*tp_str*/
-    PyObject_GenericGetAttr,/*tp_getattro*/
-    PyObject_GenericSetAttr,/*tp_setattro*/
-    0,                      /*tp_as_buffer*/
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE, /*tp_flags*/
-    BZ2Comp__doc__,         /*tp_doc*/
-    0,                      /*tp_traverse*/
-    0,                      /*tp_clear*/
-    0,                      /*tp_richcompare*/
-    0,                      /*tp_weaklistoffset*/
-    0,                      /*tp_iter*/
-    0,                      /*tp_iternext*/
-    BZ2Comp_methods,        /*tp_methods*/
-    0,                      /*tp_members*/
-    0,                      /*tp_getset*/
-    0,                      /*tp_base*/
-    0,                      /*tp_dict*/
-    0,                      /*tp_descr_get*/
-    0,                      /*tp_descr_set*/
-    0,                      /*tp_dictoffset*/
-    (initproc)BZ2Comp_init, /*tp_init*/
-    PyType_GenericAlloc,    /*tp_alloc*/
-    PyType_GenericNew,      /*tp_new*/
-    PyObject_Free,          /*tp_free*/
-    0,                      /*tp_is_gc*/
-};
-
-
-/* ===================================================================== */
-/* Members of BZ2Decomp. */
-
-#undef OFF
-#define OFF(x) offsetof(BZ2DecompObject, x)
-
-static PyMemberDef BZ2Decomp_members[] = {
-    {"unused_data", T_OBJECT, OFF(unused_data), READONLY},
-    {NULL}      /* Sentinel */
-};
-
-
-/* ===================================================================== */
-/* Methods of BZ2Decomp. */
-
-PyDoc_STRVAR(BZ2Decomp_decompress__doc__,
-"decompress(data) -> string\n\
-\n\
-Provide more data to the decompressor object. It will return chunks\n\
-of decompressed data whenever possible. If you try to decompress data\n\
-after the end of stream is found, EOFError will be raised. If any data\n\
-was found after the end of stream, it'll be ignored and saved in\n\
-unused_data attribute.\n\
-");
-
-static PyObject *
-BZ2Decomp_decompress(BZ2DecompObject *self, PyObject *args)
-{
-    Py_buffer pdata;
-    char *data;
-    int datasize;
-    int bufsize = SMALLCHUNK;
-    PY_LONG_LONG totalout;
-    PyObject *ret = NULL;
-    bz_stream *bzs = &self->bzs;
-    int bzerror;
-
-    if (!PyArg_ParseTuple(args, "y*:decompress", &pdata))
-        return NULL;
-    data = pdata.buf;
-    datasize = pdata.len;
-
-    ACQUIRE_LOCK(self);
-    if (!self->running) {
-        PyErr_SetString(PyExc_EOFError, "end of stream was "
-                                        "already found");
-        goto error;
-    }
-
-    ret = PyBytes_FromStringAndSize(NULL, bufsize);
-    if (!ret)
-        goto error;
-
-    bzs->next_in = data;
-    bzs->avail_in = datasize;
-    bzs->next_out = BUF(ret);
-    bzs->avail_out = bufsize;
-
-    totalout = BZS_TOTAL_OUT(bzs);
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        bzerror = BZ2_bzDecompress(bzs);
-        Py_END_ALLOW_THREADS
-        if (bzerror == BZ_STREAM_END) {
-            if (bzs->avail_in != 0) {
-                Py_DECREF(self->unused_data);
-                self->unused_data =
-                    PyBytes_FromStringAndSize(bzs->next_in,
-                                               bzs->avail_in);
-            }
-            self->running = 0;
-            break;
-        }
-        if (bzerror != BZ_OK) {
-            Util_CatchBZ2Error(bzerror);
-            goto error;
-        }
-        if (bzs->avail_in == 0)
-            break; /* no more input data */
-        if (bzs->avail_out == 0) {
-            bufsize = Util_NewBufferSize(bufsize);
-            if (_PyBytes_Resize(&ret, bufsize) < 0) {
-                BZ2_bzDecompressEnd(bzs);
-                goto error;
-            }
-            bzs->next_out = BUF(ret);
-            bzs->next_out = BUF(ret) + (BZS_TOTAL_OUT(bzs)
-                                        - totalout);
-            bzs->avail_out = bufsize - (bzs->next_out - BUF(ret));
-        }
-    }
-
-    if (bzs->avail_out != 0) {
-        if (_PyBytes_Resize(&ret,
-                    (Py_ssize_t)(BZS_TOTAL_OUT(bzs) - totalout)) < 0)
-            goto error;
-    }
-
-    RELEASE_LOCK(self);
-    PyBuffer_Release(&pdata);
-    return ret;
-
-error:
-    RELEASE_LOCK(self);
-    PyBuffer_Release(&pdata);
-    Py_XDECREF(ret);
-    return NULL;
-}
-
-static PyMethodDef BZ2Decomp_methods[] = {
-    {"decompress", (PyCFunction)BZ2Decomp_decompress, METH_VARARGS, BZ2Decomp_decompress__doc__},
-    {NULL,              NULL}           /* sentinel */
-};
-
-
-/* ===================================================================== */
-/* Slot definitions for BZ2Decomp_Type. */
-
-static int
-BZ2Decomp_init(BZ2DecompObject *self, PyObject *args, PyObject *kwargs)
-{
-    int bzerror;
-
-    if (!PyArg_ParseTuple(args, ":BZ2Decompressor"))
-        return -1;
-
-#ifdef WITH_THREAD
-    self->lock = PyThread_allocate_lock();
-    if (!self->lock) {
-        PyErr_SetString(PyExc_MemoryError, "unable to allocate lock");
-        goto error;
-    }
-#endif
-
-    self->unused_data = PyBytes_FromStringAndSize("", 0);
-    if (!self->unused_data)
-        goto error;
-
-    memset(&self->bzs, 0, sizeof(bz_stream));
-    bzerror = BZ2_bzDecompressInit(&self->bzs, 0, 0);
-    if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        goto error;
-    }
-
-    self->running = 1;
-
-    return 0;
-
-error:
-#ifdef WITH_THREAD
-    if (self->lock) {
-        PyThread_free_lock(self->lock);
-        self->lock = NULL;
-    }
-#endif
-    Py_CLEAR(self->unused_data);
-    return -1;
-}
-
-static void
-BZ2Decomp_dealloc(BZ2DecompObject *self)
-{
-#ifdef WITH_THREAD
-    if (self->lock)
-        PyThread_free_lock(self->lock);
-#endif
-    Py_XDECREF(self->unused_data);
-    BZ2_bzDecompressEnd(&self->bzs);
-    Py_TYPE(self)->tp_free((PyObject *)self);
-}
-
-
-/* ===================================================================== */
-/* BZ2Decomp_Type definition. */
-
-PyDoc_STRVAR(BZ2Decomp__doc__,
-"BZ2Decompressor() -> decompressor object\n\
-\n\
-Create a new decompressor object. This object may be used to decompress\n\
-data sequentially. If you want to decompress data in one shot, use the\n\
-decompress() function instead.\n\
-");
-
-static PyTypeObject BZ2Decomp_Type = {
-    PyVarObject_HEAD_INIT(NULL, 0)
-    "bz2.BZ2Decompressor",      /*tp_name*/
-    sizeof(BZ2DecompObject), /*tp_basicsize*/
-    0,                          /*tp_itemsize*/
-    (destructor)BZ2Decomp_dealloc, /*tp_dealloc*/
-    0,                          /*tp_print*/
-    0,                          /*tp_getattr*/
-    0,                          /*tp_setattr*/
-    0,                          /*tp_reserved*/
-    0,                          /*tp_repr*/
-    0,                          /*tp_as_number*/
-    0,                          /*tp_as_sequence*/
-    0,                          /*tp_as_mapping*/
-    0,                          /*tp_hash*/
-    0,                      /*tp_call*/
-    0,                      /*tp_str*/
-    PyObject_GenericGetAttr,/*tp_getattro*/
-    PyObject_GenericSetAttr,/*tp_setattro*/
-    0,                      /*tp_as_buffer*/
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE, /*tp_flags*/
-    BZ2Decomp__doc__,       /*tp_doc*/
-    0,                      /*tp_traverse*/
-    0,                      /*tp_clear*/
-    0,                      /*tp_richcompare*/
-    0,                      /*tp_weaklistoffset*/
-    0,                      /*tp_iter*/
-    0,                      /*tp_iternext*/
-    BZ2Decomp_methods,      /*tp_methods*/
-    BZ2Decomp_members,      /*tp_members*/
-    0,                      /*tp_getset*/
-    0,                      /*tp_base*/
-    0,                      /*tp_dict*/
-    0,                      /*tp_descr_get*/
-    0,                      /*tp_descr_set*/
-    0,                      /*tp_dictoffset*/
-    (initproc)BZ2Decomp_init, /*tp_init*/
-    PyType_GenericAlloc,    /*tp_alloc*/
-    PyType_GenericNew,      /*tp_new*/
-    PyObject_Free,          /*tp_free*/
-    0,                      /*tp_is_gc*/
-};
-
-
-/* ===================================================================== */
-/* Module functions. */
-
-PyDoc_STRVAR(bz2_compress__doc__,
-"compress(data [, compresslevel=9]) -> string\n\
-\n\
-Compress data in one shot. If you want to compress data sequentially,\n\
-use an instance of BZ2Compressor instead. The compresslevel parameter, if\n\
-given, must be a number between 1 and 9.\n\
-");
-
-static PyObject *
-bz2_compress(PyObject *self, PyObject *args, PyObject *kwargs)
-{
-    int compresslevel=9;
-    Py_buffer pdata;
-    char *data;
-    int datasize;
-    int bufsize;
-    PyObject *ret = NULL;
-    bz_stream _bzs;
-    bz_stream *bzs = &_bzs;
-    int bzerror;
-    static char *kwlist[] = {"data", "compresslevel", 0};
-
-    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "y*|i",
-                                     kwlist, &pdata,
-                                     &compresslevel))
-        return NULL;
-    data = pdata.buf;
-    datasize = pdata.len;
-
-    if (compresslevel < 1 || compresslevel > 9) {
-        PyErr_SetString(PyExc_ValueError,
-                        "compresslevel must be between 1 and 9");
-        PyBuffer_Release(&pdata);
-        return NULL;
-    }
-
-    /* Conforming to bz2 manual, this is large enough to fit compressed
-     * data in one shot. We will check it later anyway. */
-    bufsize = datasize + (datasize/100+1) + 600;
-
-    ret = PyBytes_FromStringAndSize(NULL, bufsize);
-    if (!ret) {
-        PyBuffer_Release(&pdata);
-        return NULL;
-    }
-
-    memset(bzs, 0, sizeof(bz_stream));
-
-    bzs->next_in = data;
-    bzs->avail_in = datasize;
-    bzs->next_out = BUF(ret);
-    bzs->avail_out = bufsize;
-
-    bzerror = BZ2_bzCompressInit(bzs, compresslevel, 0, 0);
-    if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        PyBuffer_Release(&pdata);
-        Py_DECREF(ret);
-        return NULL;
-    }
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        bzerror = BZ2_bzCompress(bzs, BZ_FINISH);
-        Py_END_ALLOW_THREADS
-        if (bzerror == BZ_STREAM_END) {
-            break;
-        } else if (bzerror != BZ_FINISH_OK) {
-            BZ2_bzCompressEnd(bzs);
-            Util_CatchBZ2Error(bzerror);
-            PyBuffer_Release(&pdata);
-            Py_DECREF(ret);
-            return NULL;
-        }
-        if (bzs->avail_out == 0) {
-            bufsize = Util_NewBufferSize(bufsize);
-            if (_PyBytes_Resize(&ret, bufsize) < 0) {
-                BZ2_bzCompressEnd(bzs);
-                PyBuffer_Release(&pdata);
-                return NULL;
-            }
-            bzs->next_out = BUF(ret) + BZS_TOTAL_OUT(bzs);
-            bzs->avail_out = bufsize - (bzs->next_out - BUF(ret));
-        }
-    }
-
-    if (bzs->avail_out != 0) {
-        if (_PyBytes_Resize(&ret, (Py_ssize_t)BZS_TOTAL_OUT(bzs)) < 0) {
-            ret = NULL;
-        }
-    }
-    BZ2_bzCompressEnd(bzs);
-
-    PyBuffer_Release(&pdata);
-    return ret;
-}
-
-PyDoc_STRVAR(bz2_decompress__doc__,
-"decompress(data) -> decompressed data\n\
-\n\
-Decompress data in one shot. If you want to decompress data sequentially,\n\
-use an instance of BZ2Decompressor instead.\n\
-");
-
-static PyObject *
-bz2_decompress(PyObject *self, PyObject *args)
-{
-    Py_buffer pdata;
-    char *data;
-    int datasize;
-    int bufsize = SMALLCHUNK;
-    PyObject *ret;
-    bz_stream _bzs;
-    bz_stream *bzs = &_bzs;
-    int bzerror;
-
-    if (!PyArg_ParseTuple(args, "y*:decompress", &pdata))
-        return NULL;
-    data = pdata.buf;
-    datasize = pdata.len;
-
-    if (datasize == 0) {
-        PyBuffer_Release(&pdata);
-        return PyBytes_FromStringAndSize("", 0);
-    }
-
-    ret = PyBytes_FromStringAndSize(NULL, bufsize);
-    if (!ret) {
-        PyBuffer_Release(&pdata);
-        return NULL;
-    }
-
-    memset(bzs, 0, sizeof(bz_stream));
-
-    bzs->next_in = data;
-    bzs->avail_in = datasize;
-    bzs->next_out = BUF(ret);
-    bzs->avail_out = bufsize;
-
-    bzerror = BZ2_bzDecompressInit(bzs, 0, 0);
-    if (bzerror != BZ_OK) {
-        Util_CatchBZ2Error(bzerror);
-        Py_DECREF(ret);
-        PyBuffer_Release(&pdata);
-        return NULL;
-    }
-
-    for (;;) {
-        Py_BEGIN_ALLOW_THREADS
-        bzerror = BZ2_bzDecompress(bzs);
-        Py_END_ALLOW_THREADS
-        if (bzerror == BZ_STREAM_END) {
-            break;
-        } else if (bzerror != BZ_OK) {
-            BZ2_bzDecompressEnd(bzs);
-            Util_CatchBZ2Error(bzerror);
-            PyBuffer_Release(&pdata);
-            Py_DECREF(ret);
-            return NULL;
-        }
-        if (bzs->avail_in == 0) {
-            BZ2_bzDecompressEnd(bzs);
-            PyErr_SetString(PyExc_ValueError,
-                            "couldn't find end of stream");
-            PyBuffer_Release(&pdata);
-            Py_DECREF(ret);
-            return NULL;
-        }
-        if (bzs->avail_out == 0) {
-            bufsize = Util_NewBufferSize(bufsize);
-            if (_PyBytes_Resize(&ret, bufsize) < 0) {
-                BZ2_bzDecompressEnd(bzs);
-                PyBuffer_Release(&pdata);
-                return NULL;
-            }
-            bzs->next_out = BUF(ret) + BZS_TOTAL_OUT(bzs);
-            bzs->avail_out = bufsize - (bzs->next_out - BUF(ret));
-        }
-    }
-
-    if (bzs->avail_out != 0) {
-        if (_PyBytes_Resize(&ret, (Py_ssize_t)BZS_TOTAL_OUT(bzs)) < 0) {
-            ret = NULL;
-        }
-    }
-    BZ2_bzDecompressEnd(bzs);
-    PyBuffer_Release(&pdata);
-
-    return ret;
-}
-
-static PyMethodDef bz2_methods[] = {
-    {"compress", (PyCFunction) bz2_compress, METH_VARARGS|METH_KEYWORDS,
-        bz2_compress__doc__},
-    {"decompress", (PyCFunction) bz2_decompress, METH_VARARGS,
-        bz2_decompress__doc__},
-    {NULL,              NULL}           /* sentinel */
-};
-
-/* ===================================================================== */
-/* Initialization function. */
-
-PyDoc_STRVAR(bz2__doc__,
-"The python bz2 module provides a comprehensive interface for\n\
-the bz2 compression library. It implements a complete file\n\
-interface, one shot (de)compression functions, and types for\n\
-sequential (de)compression.\n\
-");
-
-
-static struct PyModuleDef bz2module = {
-    PyModuleDef_HEAD_INIT,
-    "bz2",
-    bz2__doc__,
-    -1,
-    bz2_methods,
-    NULL,
-    NULL,
-    NULL,
-    NULL
-};
-
-PyMODINIT_FUNC
-PyInit_bz2(void)
-{
-    PyObject *m;
-
-    if (PyType_Ready(&BZ2File_Type) < 0)
-        return NULL;
-    if (PyType_Ready(&BZ2Comp_Type) < 0)
-        return NULL;
-    if (PyType_Ready(&BZ2Decomp_Type) < 0)
-        return NULL;
-
-    m = PyModule_Create(&bz2module);
-    if (m == NULL)
-        return NULL;
-
-    PyModule_AddObject(m, "__author__", PyUnicode_FromString(__author__));
-
-    Py_INCREF(&BZ2File_Type);
-    PyModule_AddObject(m, "BZ2File", (PyObject *)&BZ2File_Type);
-
-    Py_INCREF(&BZ2Comp_Type);
-    PyModule_AddObject(m, "BZ2Compressor", (PyObject *)&BZ2Comp_Type);
-
-    Py_INCREF(&BZ2Decomp_Type);
-    PyModule_AddObject(m, "BZ2Decompressor", (PyObject *)&BZ2Decomp_Type);
-    return m;
-}
diff --git a/PCbuild/bz2.vcproj b/PCbuild/_bz2.vcproj
similarity index 99%
rename from PCbuild/bz2.vcproj
rename to PCbuild/_bz2.vcproj
index 035736e..e6b9c88 100644
--- a/PCbuild/bz2.vcproj
+++ b/PCbuild/_bz2.vcproj
@@ -2,7 +2,7 @@
 <VisualStudioProject
 	ProjectType="Visual C++"
 	Version="9,00"
-	Name="bz2"
+	Name="_bz2"
 	ProjectGUID="{73FCD2BD-F133-46B7-8EC1-144CD82A59D5}"
 	RootNamespace="bz2"
 	Keyword="Win32Proj"
@@ -527,7 +527,7 @@
 			Name="Source Files"
 			>
 			<File
-				RelativePath="..\Modules\bz2module.c"
+				RelativePath="..\Modules\_bz2module.c"
 				>
 			</File>
 		</Filter>
diff --git a/PCbuild/pcbuild.sln b/PCbuild/pcbuild.sln
index 1de4ea1..ed3a7a0 100644
--- a/PCbuild/pcbuild.sln
+++ b/PCbuild/pcbuild.sln
@@ -87,7 +87,7 @@
 		{CF7AC3D1-E2DF-41D2-BEA6-1E2556CDEA26} = {CF7AC3D1-E2DF-41D2-BEA6-1E2556CDEA26}
 	EndProjectSection
 EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "bz2", "bz2.vcproj", "{73FCD2BD-F133-46B7-8EC1-144CD82A59D5}"
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "_bz2", "_bz2.vcproj", "{73FCD2BD-F133-46B7-8EC1-144CD82A59D5}"
 	ProjectSection(ProjectDependencies) = postProject
 		{CF7AC3D1-E2DF-41D2-BEA6-1E2556CDEA26} = {CF7AC3D1-E2DF-41D2-BEA6-1E2556CDEA26}
 	EndProjectSection
diff --git a/PCbuild/readme.txt b/PCbuild/readme.txt
index af432c4..11ab127 100644
--- a/PCbuild/readme.txt
+++ b/PCbuild/readme.txt
@@ -112,9 +112,9 @@
     pre-built Tcl/Tk in either ..\..\tcltk for 32-bit or ..\..\tcltk64 for
     64-bit (relative to this directory).  See below for instructions to build
     Tcl/Tk. 
-bz2
-    Python wrapper for the libbz2 compression library.  Homepage
-        http://sources.redhat.com/bzip2/
+_bz2
+    Python wrapper for the libbzip2 compression library.  Homepage
+        http://www.bzip.org/
     Download the source from the python.org copy into the dist
     directory:
 
diff --git a/setup.py b/setup.py
index add71ba..05e1133 100644
--- a/setup.py
+++ b/setup.py
@@ -1233,11 +1233,11 @@
                 bz2_extra_link_args = ('-Wl,-search_paths_first',)
             else:
                 bz2_extra_link_args = ()
-            exts.append( Extension('bz2', ['bz2module.c'],
+            exts.append( Extension('_bz2', ['_bz2module.c'],
                                    libraries = ['bz2'],
                                    extra_link_args = bz2_extra_link_args) )
         else:
-            missing.append('bz2')
+            missing.append('_bz2')
 
         # Interface to the Expat XML parser
         #