venv/lib/python3.11/site-packages/pip/_vendor/urllib3/util/response.py

   1 from __future__ import absolute_import
   2
   3 from email.errors import MultipartInvariantViolationDefect, StartBoundaryNotFoundDefect
   4
   5 from ..exceptions import HeaderParsingError
   6 from ..packages.six.moves import http_client as httplib
   7
   8
   9 def is_fp_closed(obj):
  10     """
  11     Checks whether a given file-like object is closed.
  12
  13     :param obj:
  14         The file-like object to check.
  15     """
  16
  17     try:
  18         # Check `isclosed()` first, in case Python3 doesn't set `closed`.
  19         # GH Issue #928
  20         return obj.isclosed()
  21     except AttributeError:
  22         pass
  23
  24     try:
  25         # Check via the official file-like-object way.
  26         return obj.closed
  27     except AttributeError:
  28         pass
  29
  30     try:
  31         # Check if the object is a container for another file-like object that
  32         # gets released on exhaustion (e.g. HTTPResponse).
  33         return obj.fp is None
  34     except AttributeError:
  35         pass
  36
  37     raise ValueError("Unable to determine whether fp is closed.")
  38
  39
  40 def assert_header_parsing(headers):
  41     """
  42     Asserts whether all headers have been successfully parsed.
  43     Extracts encountered errors from the result of parsing headers.
  44
  45     Only works on Python 3.
  46
  47     :param http.client.HTTPMessage headers: Headers to verify.
  48
  49     :raises urllib3.exceptions.HeaderParsingError:
  50         If parsing errors are found.
  51     """
  52
  53     # This will fail silently if we pass in the wrong kind of parameter.
  54     # To make debugging easier add an explicit check.
  55     if not isinstance(headers, httplib.HTTPMessage):
  56         raise TypeError("expected httplib.Message, got {0}.".format(type(headers)))
  57
  58     defects = getattr(headers, "defects", None)
  59     get_payload = getattr(headers, "get_payload", None)
  60
  61     unparsed_data = None
  62     if get_payload:
  63         # get_payload is actually email.message.Message.get_payload;
  64         # we're only interested in the result if it's not a multipart message
  65         if not headers.is_multipart():
  66             payload = get_payload()
  67
  68             if isinstance(payload, (bytes, str)):
  69                 unparsed_data = payload
  70     if defects:
  71         # httplib is assuming a response body is available
  72         # when parsing headers even when httplib only sends
  73         # header data to parse_headers() This results in
  74         # defects on multipart responses in particular.
  75         # See: https://github.com/urllib3/urllib3/issues/800
  76
  77         # So we ignore the following defects:
  78         # - StartBoundaryNotFoundDefect:
  79         #     The claimed start boundary was never found.
  80         # - MultipartInvariantViolationDefect:
  81         #     A message claimed to be a multipart but no subparts were found.
  82         defects = [
  83             defect
  84             for defect in defects
  85             if not isinstance(
  86                 defect, (StartBoundaryNotFoundDefect, MultipartInvariantViolationDefect)
  87             )
  88         ]
  89
  90     if defects or unparsed_data:
  91         raise HeaderParsingError(defects=defects, unparsed_data=unparsed_data)
  92
  93
  94 def is_response_to_head(response):
  95     """
  96     Checks whether the request of a response has been a HEAD-request.
  97     Handles the quirks of AppEngine.
  98
  99     :param http.client.HTTPResponse response:
 100         Response to check if the originating request
 101         used 'HEAD' as a method.
 102     """
 103     # FIXME: Can we do this somehow without accessing private httplib _method?
 104     method = response._method
 105     if isinstance(method, int):  # Platform-specific: Appengine
 106         return method == 3
 107     return method.upper() == "HEAD"