Commit 59a34c43 authored by Kevin Christopher Henry's avatar Kevin Christopher Henry Committed by Tim Graham
Browse files

Fixed #18744 -- Updated docstring to highlight limitations of NamedTemporaryFile 

- Noted that this does not allow for reading and writing the same open
file in different processes under Windows.
- Noted that the keyword arguments to NamedTemporaryFile no longer
match the Python version.
parent 4e9f8007

django/core/files/temp.py

+21 −10
Original line number Diff line number Diff line 
"""

The temp module provides a NamedTemporaryFile that can be re-opened on any

platform. Most platforms use the standard Python tempfile.TemporaryFile class,

but MS Windows users are given a custom class.

The temp module provides a NamedTemporaryFile that can be reopened in the same

process on any platform. Most platforms use the standard Python

tempfile.NamedTemporaryFile class, but Windows users are given a custom class.



This is needed because in Windows NT, the default implementation of

NamedTemporaryFile uses the O_TEMPORARY flag, and thus cannot be reopened [1].

This is needed because the Python implementation of NamedTemporaryFile uses the

O_TEMPORARY flag under Windows, which prevents the file from being reopened

if the same flag is not provided [1][2]. Note that this does not address the

more general issue of opening a file for writing and reading in multiple

processes in a manner that works across platforms.



1: http://mail.python.org/pipermail/python-list/2005-December/359474.html

Also note that the custom version of NamedTemporaryFile does not support the

full range of keyword arguments available in Python 2.6+ and 3.0+.



1: https://mail.python.org/pipermail/python-list/2005-December/336958.html

2: http://bugs.python.org/issue14243

"""



import os
@@ -15,16 +22,20 @@ from django.core.files.utils import FileProxyMixin 


__all__ = ('NamedTemporaryFile', 'gettempdir',)





if os.name == 'nt':

    class TemporaryFile(FileProxyMixin):

        """

        Temporary file object constructor that works in Windows and supports

        reopening of the temporary file in windows.

        Temporary file object constructor that supports reopening of the

        temporary file in Windows.



        Note that __init__() does not support the 'delete' keyword argument in

        Python 2.6+, or the 'delete', 'buffering', 'encoding', or 'newline'

        keyword arguments in Python 3.0+.

        """

        def __init__(self, mode='w+b', bufsize=-1, suffix='', prefix='',

                dir=None):

            fd, name = tempfile.mkstemp(suffix=suffix, prefix=prefix,

                                          dir=dir)

            fd, name = tempfile.mkstemp(suffix=suffix, prefix=prefix, dir=dir)

            self.name = name

            self.file = os.fdopen(fd, mode, bufsize)

            self.close_called = False