1 """This package contains all WSGI specific code for cubicweb

     2 

     3 NOTE: this package borrows a lot of code to Django

     4       (http://www.djangoproject.com) and to the wsgiref module

     5       of the python2.5's stdlib.

     6 

     7 WSGI corresponding PEP: http://www.python.org/dev/peps/pep-0333/

     8 

     9 :organization: Logilab

    10 :copyright: 2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

    11 :contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

    12 """

    13 __docformat__ = "restructuredtext en"

    14 

    15 from email import message, message_from_string

    16 from Cookie import SimpleCookie

    17 from StringIO import StringIO

    18 from cgi import parse_header, parse_qsl

    19 from pprint import pformat as _pformat

    20 

    21 

    22 def pformat(obj):

    23     """pretty prints `obj` if possible"""

    24     try:

    25         return _pformat(obj)

    26     except:

    27         return u'<could not parse>'

    28     

    29 def qs2dict(qs):

    30     """transforms a query string into a regular python dict"""

    31     result = {}

    32     for key, value in parse_qsl(qs, True):

    33         result.setdefault(key, []).append(value)

    34     return result

    35 

    36 def normalize_header(header):

    37     """returns a normalized header name

    38     

    39     >>> normalize_header('User_Agent')

    40     'User-agent'

    41     """

    42     return header.replace('_', '-').capitalize()

    43 

    44 def safe_copyfileobj(fsrc, fdst, length=16*1024, size=0):

    45     """

    46     THIS COMES FROM DJANGO

    47     A version of shutil.copyfileobj that will not read more than 'size' bytes.

    48     This makes it safe from clients sending more than CONTENT_LENGTH bytes of

    49     data in the body.

    50     """

    51     if not size:

    52         return

    53     while size > 0:

    54         buf = fsrc.read(min(length, size))

    55         if not buf:

    56             break

    57         fdst.write(buf)

    58         size -= len(buf)

    59 

    60 def parse_file_upload(header_dict, post_data):

    61     """This is adapted FROM DJANGO"""

    62     raw_message = '\r\n'.join('%s:%s' % pair for pair in header_dict.iteritems())

    63     raw_message += '\r\n\r\n' + post_data

    64     msg = message_from_string(raw_message)

    65     post, files = {}, {}

    66     for submessage in msg.get_payload():

    67         name_dict = parse_header(submessage['Content-Disposition'])[1]

    68         key = name_dict['name']

    69         # name_dict is something like {'name': 'file', 'filename': 'test.txt'} for file uploads

    70         # or {'name': 'blah'} for POST fields

    71         # We assume all uploaded files have a 'filename' set.

    72         if 'filename' in name_dict:

    73             assert type([]) != type(submessage.get_payload()), "Nested MIME messages are not supported"

    74             if not name_dict['filename'].strip():

    75                 continue

    76             # IE submits the full path, so trim everything but the basename.

    77             # (We can't use os.path.basename because that uses the server's

    78             # directory separator, which may not be the same as the

    79             # client's one.)

    80             filename = name_dict['filename'][name_dict['filename'].rfind("\\")+1:]

    81             mimetype = 'Content-Type' in submessage and submessage['Content-Type'] or None

    82             content = StringIO(submessage.get_payload())

    83             files[key] = [filename, mimetype, content]

    84         else:

    85             post.setdefault(key, []).append(submessage.get_payload())

    86     return post, files

    87