webob.response 源代码

import re
import struct
import zlib
from base64 import b64encode
from datetime import datetime, timedelta
from hashlib import md5

from webob.byterange import ContentRange
from webob.cachecontrol import CacheControl, serialize_cache_control
from webob.compat import (
    PY2,
    bytes_,
    native_,
    string_types,
    text_type,
    url_quote,
    urlparse,
)
from webob.cookies import Cookie, make_cookie
from webob.datetime_utils import (
    parse_date_delta,
    serialize_date_delta,
    timedelta_to_seconds,
)
from webob.descriptors import (
    CHARSET_RE,
    SCHEME_RE,
    converter,
    date_header,
    header_getter,
    list_header,
    parse_auth,
    parse_content_range,
    parse_etag_response,
    parse_int,
    parse_int_safe,
    serialize_auth,
    serialize_content_range,
    serialize_etag_response,
    serialize_int,
)
from webob.headers import ResponseHeaders
from webob.request import BaseRequest
from webob.util import status_generic_reasons, status_reasons, warn_deprecation

try:
    import simplejson as json
except ImportError:
    import json

__all__ = ['Response']

_PARAM_RE = re.compile(r'([a-z0-9]+)=(?:"([^"]*)"|([a-z0-9_.-]*))', re.I)
_OK_PARAM_RE = re.compile(r'^[a-z0-9_.-]+$', re.I)

_gzip_header = b'\x1f\x8b\x08\x00\x00\x00\x00\x00\x02\xff'

_marker = object()

class Response(object):
    """
    Represents a WSGI response.

    If no arguments are passed, creates a :class:`~Response` that uses a
    variety of defaults. The defaults may be changed by sub-classing the
    :class:`~Response`. See the :ref:`sub-classing notes
    <response_subclassing_notes>`.

    :cvar ~Response.body: If ``body`` is a ``text_type``, then it will be
        encoded using either ``charset`` when provided or ``default_encoding``
        when ``charset`` is not provided if the ``content_type`` allows for a
        ``charset``. This argument is mutually  exclusive with ``app_iter``.

    :vartype ~Response.body: bytes or text_type

    :cvar ~Response.status: Either an :class:`int` or a string that is
        an integer followed by the status text. If it is an integer, it will be
        converted to a proper status that also includes the status text.  Any
        existing status text will be kept. Non-standard values are allowed.

    :vartype ~Response.status: int or str

    :cvar ~Response.headerlist: A list of HTTP headers for the response.

    :vartype ~Response.headerlist: list

    :cvar ~Response.app_iter: An iterator that is used as the body of the
        response. Should conform to the WSGI requirements and should provide
        bytes. This argument is mutually exclusive with ``body``.

    :vartype ~Response.app_iter: iterable

    :cvar ~Response.content_type: Sets the ``Content-Type`` header. If no
        ``content_type`` is provided, and there is no ``headerlist``, the
        ``default_content_type`` will be automatically set. If ``headerlist``
        is provided then this value is ignored.

    :vartype ~Response.content_type: str or None

    :cvar conditional_response: Used to change the behavior of the
        :class:`~Response` to check the original request for conditional
        response headers. See :meth:`~Response.conditional_response_app` for
        more information.

    :vartype conditional_response: bool

    :cvar ~Response.charset: Adds a ``charset`` ``Content-Type`` parameter. If
        no ``charset`` is provided and the ``Content-Type`` is text, then the
        ``default_charset`` will automatically be added.  Currently the only
        ``Content-Type``'s that allow for a ``charset`` are defined to be
        ``text/*``, ``application/xml``, and ``*/*+xml``. Any other
        ``Content-Type``'s will not have a ``charset`` added. If a
        ``headerlist`` is provided this value is ignored.

    :vartype ~Response.charset: str or None

    All other response attributes may be set on the response by providing them
    as keyword arguments. A :exc:`TypeError` will be raised for any unexpected
    keywords.

    .. _response_subclassing_notes:

    **Sub-classing notes:**

    * The ``default_content_type`` is used as the default for the
      ``Content-Type`` header that is returned on the response. It is
      ``text/html``.

    * The ``default_charset`` is used as the default character set to return on
      the ``Content-Type`` header, if the ``Content-Type`` allows for a
      ``charset`` parameter. Currently the only ``Content-Type``'s that allow
      for a ``charset`` are defined to be: ``text/*``, ``application/xml``, and
      ``*/*+xml``. Any other ``Content-Type``'s will not have a ``charset``
      added.

    * The ``unicode_errors`` is set to ``strict``, and access on a
      :attr:`~Response.text` will raise an error if it fails to decode the
      :attr:`~Response.body`.

    * ``default_conditional_response`` is set to ``False``. This flag may be
      set to ``True`` so that all ``Response`` objects will attempt to check
      the original request for conditional response headers. See
      :meth:`~Response.conditional_response_app` for more information.

    * ``default_body_encoding`` is set to 'UTF-8' by default. It exists to
      allow users to get/set the ``Response`` object using ``.text``, even if
      no ``charset`` has been set for the ``Content-Type``.
    """

    default_content_type = 'text/html'
    default_charset = 'UTF-8'
    unicode_errors = 'strict'
    default_conditional_response = False
    default_body_encoding = 'UTF-8'

    # These two are only around so that when people pass them into the
    # constructor they correctly get saved and set, however they are not used
    # by any part of the Response. See commit
    # 627593bbcd4ab52adc7ee569001cdda91c670d5d for rationale.
    request = None
    environ = None

    #
    # __init__, from_file, copy
    #

    def __init__(self, body=None, status=None, headerlist=None, app_iter=None,
                 content_type=None, conditional_response=None, charset=_marker,
                 **kw):
        # Do some sanity checking, and turn json_body into an actual body
        if app_iter is None and body is None and ('json_body' in kw or 'json' in kw):
            if 'json_body' in kw:
                json_body = kw.pop('json_body')
            else:
                json_body = kw.pop('json')
            body = json.dumps(json_body, separators=(',', ':')).encode('UTF-8')

            if content_type is None:
                content_type = 'application/json'

        if app_iter is None:
            if body is None:
                body = b''
        elif body is not None:
            raise TypeError(
                "You may only give one of the body and app_iter arguments")

        # Set up Response.status
        if status is None:
            self._status = '200 OK'
        else:
            self.status = status

        # Initialize headers
        self._headers = None
        if headerlist is None:
            self._headerlist = []
        else:
            self._headerlist = headerlist

        # Set the encoding for the Response to charset, so if a charset is
        # passed but the Content-Type does not allow for a charset, we can
        # still encode text_type body's.
        # r = Response(
        #   content_type='application/foo',
        #   charset='UTF-8',
        #   body=u'somebody')
        # Should work without issues, and the header will be correctly set to
        # Content-Type: application/foo with no charset on it.

        encoding = None
        if charset is not _marker:
            encoding = charset

        # Does the status code have a body or not?
        code_has_body = (
            self._status[0] != '1' and
            self._status[:3] not in ('204', '205', '304')
        )

        # We only set the content_type to the one passed to the constructor or
        # the default content type if there is none that exists AND there was
        # no headerlist passed. If a headerlist was provided then most likely
        # the ommission of the Content-Type is on purpose and we shouldn't try
        # to be smart about it.
        #
        # Also allow creation of a empty Response with just the status set to a
        # Response with empty body, such as Response(status='204 No Content')
        # without the default content_type being set (since empty bodies have
        # no Content-Type)
        #
        # Check if content_type is set because default_content_type could be
        # None, in which case there is no content_type, and thus we don't need
        # to anything

        content_type = content_type or self.default_content_type

        if headerlist is None and code_has_body and content_type:
            # Set up the charset, if the content_type doesn't already have one

            has_charset = 'charset=' in content_type

            # If the Content-Type already has a charset, we don't set the user
            # provided charset on the Content-Type, so we shouldn't use it as
            # the encoding for text_type based body's.
            if has_charset:
                encoding = None

            # Do not use the default_charset for the encoding because we
            # want things like
            # Response(content_type='image/jpeg',body=u'foo') to raise when
            # trying to encode the body.

            new_charset = encoding

            if (
                not has_charset and
                charset is _marker and
                self.default_charset
            ):
                new_charset = self.default_charset

            # Optimize for the default_content_type as shipped by
            # WebOb, becuase we know that 'text/html' has a charset,
            # otherwise add a charset if the content_type has a charset.
            #
            # Even if the user supplied charset explicitly, we do not add
            # it to the Content-Type unless it has has a charset, instead
            # the user supplied charset is solely used for encoding the
            # body if it is a text_type

            if (
                new_charset and
                (
                    content_type == 'text/html' or
                    _content_type_has_charset(content_type)
                )
            ):
                content_type += '; charset=' + new_charset

            self._headerlist.append(('Content-Type', content_type))

        # Set up conditional response
        if conditional_response is None:
            self.conditional_response = self.default_conditional_response
        else:
            self.conditional_response = bool(conditional_response)

        # Set up app_iter if the HTTP Status code has a body
        if app_iter is None and code_has_body:
            if isinstance(body, text_type):
                # Fall back to trying self.charset if encoding is not set. In
                # most cases encoding will be set to the default value.
                encoding = encoding or self.charset
                if encoding is None:
                    raise TypeError(
                        "You cannot set the body to a text value without a "
                        "charset")
                body = body.encode(encoding)
            app_iter = [body]

            if headerlist is not None:
                self._headerlist[:] = [
                    (k, v)
                    for (k, v)
                    in self._headerlist
                    if k.lower() != 'content-length'
                ]
            self._headerlist.append(('Content-Length', str(len(body))))
        elif app_iter is None and not code_has_body:
            app_iter = [b'']

        self._app_iter = app_iter

        # Loop through all the remaining keyword arguments
        for name, value in kw.items():
            if not hasattr(self.__class__, name):
                # Not a basic attribute
                raise TypeError(
                    "Unexpected keyword: %s=%r" % (name, value))
            setattr(self, name, value)

[文档] @classmethod def from_file(cls, fp): """Reads a response from a file-like object (it must implement ``.read(size)`` and ``.readline()``). It will read up to the end of the response, not the end of the file. This reads the response as represented by ``str(resp)``; it may not read every valid HTTP response properly. Responses must have a ``Content-Length``.""" headerlist = [] status = fp.readline().strip() is_text = isinstance(status, text_type) if is_text: _colon = ':' _http = 'HTTP/' else: _colon = b':' _http = b'HTTP/' if status.startswith(_http): (http_ver, status_num, status_text) = status.split(None, 2) status = '%s %s' % (native_(status_num), native_(status_text)) while 1: line = fp.readline().strip() if not line: # end of headers break try: header_name, value = line.split(_colon, 1) except ValueError: raise ValueError('Bad header line: %r' % line) value = value.strip() headerlist.append(( native_(header_name, 'latin-1'), native_(value, 'latin-1') )) r = cls( status=status, headerlist=headerlist, app_iter=(), ) body = fp.read(r.content_length or 0) if is_text: r.text = body else: r.body = body return r
[文档] def copy(self): """Makes a copy of the response.""" # we need to do this for app_iter to be reusable app_iter = list(self._app_iter) iter_close(self._app_iter) # and this to make sure app_iter instances are different self._app_iter = list(app_iter) return self.__class__( status=self._status, headerlist=self._headerlist[:], app_iter=app_iter, conditional_response=self.conditional_response)
# # __repr__, __str__ # def __repr__(self): return '<%s at 0x%x %s>' % (self.__class__.__name__, abs(id(self)), self.status) def __str__(self, skip_body=False): parts = [self.status] if not skip_body: # Force enumeration of the body (to set content-length) self.body parts += map('%s: %s'.__mod__, self.headerlist) if not skip_body and self.body: parts += ['', self.body if PY2 else self.text] return '\r\n'.join(parts) # # status, status_code/status_int # def _status__get(self): """ The status string. """ return self._status def _status__set(self, value): try: code = int(value) except (ValueError, TypeError): pass else: self.status_code = code return if not PY2: if isinstance(value, bytes): value = value.decode('ascii') elif isinstance(value, text_type): value = value.encode('ascii') if not isinstance(value, str): raise TypeError( "You must set status to a string or integer (not %s)" % type(value)) # Attempt to get the status code itself, if this fails we should fail try: # We don't need this value anywhere, we just want to validate it's # an integer. So we are using the side-effect of int() raises a # ValueError as a test int(value.split()[0]) except ValueError: raise ValueError('Invalid status code, integer required.') self._status = value status = property(_status__get, _status__set, doc=_status__get.__doc__) def _status_code__get(self): """ The status as an integer. """ return int(self._status.split()[0]) def _status_code__set(self, code): try: self._status = '%d %s' % (code, status_reasons[code]) except KeyError: self._status = '%d %s' % (code, status_generic_reasons[code // 100]) status_code = status_int = property(_status_code__get, _status_code__set, doc=_status_code__get.__doc__) # # headerslist, headers # def _headerlist__get(self): """ The list of response headers. """ return self._headerlist def _headerlist__set(self, value): self._headers = None if not isinstance(value, list): if hasattr(value, 'items'): value = value.items() value = list(value) self._headerlist = value def _headerlist__del(self): self.headerlist = [] headerlist = property(_headerlist__get, _headerlist__set, _headerlist__del, doc=_headerlist__get.__doc__) def _headers__get(self): """ The headers in a dictionary-like object. """ if self._headers is None: self._headers = ResponseHeaders.view_list(self._headerlist) return self._headers def _headers__set(self, value): if hasattr(value, 'items'): value = value.items() self.headerlist = value self._headers = None headers = property(_headers__get, _headers__set, doc=_headers__get.__doc__) # # body # def _body__get(self): """ The body of the response, as a :class:`bytes`. This will read in the entire app_iter if necessary. """ app_iter = self._app_iter # try: # if len(app_iter) == 1: # return app_iter[0] # except: # pass if isinstance(app_iter, list) and len(app_iter) == 1: return app_iter[0] if app_iter is None: raise AttributeError("No body has been set") try: body = b''.join(app_iter) finally: iter_close(app_iter) if isinstance(body, text_type): raise _error_unicode_in_app_iter(app_iter, body) self._app_iter = [body] if len(body) == 0: # if body-length is zero, we assume it's a HEAD response and # leave content_length alone pass elif self.content_length is None: self.content_length = len(body) elif self.content_length != len(body): raise AssertionError( "Content-Length is different from actual app_iter length " "(%r!=%r)" % (self.content_length, len(body)) ) return body def _body__set(self, value=b''): if not isinstance(value, bytes): if isinstance(value, text_type): msg = ("You cannot set Response.body to a text object " "(use Response.text)") else: msg = ("You can only set the body to a binary type (not %s)" % type(value)) raise TypeError(msg) if self._app_iter is not None: self.content_md5 = None self._app_iter = [value] self.content_length = len(value) # def _body__del(self): # self.body = '' # #self.content_length = None body = property(_body__get, _body__set, _body__set) def _json_body__get(self): """ Set/get the body of the response as JSON. .. note:: This will automatically :meth:`~bytes.decode` the :attr:`~Response.body` as ``UTF-8`` on get, and :meth:`~str.encode` the :meth:`json.dumps` as ``UTF-8`` before assigning to :attr:`~Response.body`. """ # Note: UTF-8 is a content-type specific default for JSON return json.loads(self.body.decode('UTF-8')) def _json_body__set(self, value): self.body = json.dumps(value, separators=(',', ':')).encode('UTF-8') def _json_body__del(self): del self.body json = json_body = property(_json_body__get, _json_body__set, _json_body__del) def _has_body__get(self): """ Determine if the the response has a :attr:`~Response.body`. In contrast to simply accessing :attr:`~Response.body`, this method will **not** read the underlying :attr:`~Response.app_iter`. """ app_iter = self._app_iter if isinstance(app_iter, list) and len(app_iter) == 1: if app_iter[0] != b'': return True else: return False if app_iter is None: # pragma: no cover return False return True has_body = property(_has_body__get) # # text, unicode_body, ubody # def _text__get(self): """ Get/set the text value of the body using the ``charset`` of the ``Content-Type`` or the ``default_body_encoding``. """ if not self.charset and not self.default_body_encoding: raise AttributeError( "You cannot access Response.text unless charset or default_body_encoding" " is set" ) decoding = self.charset or self.default_body_encoding body = self.body return body.decode(decoding, self.unicode_errors) def _text__set(self, value): if not self.charset and not self.default_body_encoding: raise AttributeError( "You cannot access Response.text unless charset or default_body_encoding" " is set" ) if not isinstance(value, text_type): raise TypeError( "You can only set Response.text to a unicode string " "(not %s)" % type(value)) encoding = self.charset or self.default_body_encoding self.body = value.encode(encoding) def _text__del(self): del self.body text = property(_text__get, _text__set, _text__del, doc=_text__get.__doc__) unicode_body = ubody = property(_text__get, _text__set, _text__del, "Deprecated alias for .text") # # body_file, write(text) # def _body_file__get(self): """ A file-like object that can be used to write to the body. If you passed in a list ``app_iter``, that ``app_iter`` will be modified by writes. """ return ResponseBodyFile(self) def _body_file__set(self, file): self.app_iter = iter_file(file) def _body_file__del(self): del self.body body_file = property(_body_file__get, _body_file__set, _body_file__del, doc=_body_file__get.__doc__) def write(self, text): if not isinstance(text, bytes): if not isinstance(text, text_type): msg = "You can only write str to a Response.body_file, not %s" raise TypeError(msg % type(text)) if not self.charset: msg = ("You can only write text to Response if charset has " "been set") raise TypeError(msg) text = text.encode(self.charset) app_iter = self._app_iter if not isinstance(app_iter, list): try: new_app_iter = self._app_iter = list(app_iter) finally: iter_close(app_iter) app_iter = new_app_iter self.content_length = sum(len(chunk) for chunk in app_iter) app_iter.append(text) if self.content_length is not None: self.content_length += len(text) # # app_iter # def _app_iter__get(self): """ Returns the ``app_iter`` of the response. If ``body`` was set, this will create an ``app_iter`` from that ``body`` (a single-item list). """ return self._app_iter def _app_iter__set(self, value): if self._app_iter is not None: # Undo the automatically-set content-length self.content_length = None self._app_iter = value def _app_iter__del(self): self._app_iter = [] self.content_length = None app_iter = property(_app_iter__get, _app_iter__set, _app_iter__del, doc=_app_iter__get.__doc__) # # headers attrs # allow = list_header('Allow', '14.7') # TODO: (maybe) support response.vary += 'something' # TODO: same thing for all listy headers vary = list_header('Vary', '14.44') content_length = converter( header_getter('Content-Length', '14.17'), parse_int, serialize_int, 'int') content_encoding = header_getter('Content-Encoding', '14.11') content_language = list_header('Content-Language', '14.12') content_location = header_getter('Content-Location', '14.14') content_md5 = header_getter('Content-MD5', '14.14') content_disposition = header_getter('Content-Disposition', '19.5.1') accept_ranges = header_getter('Accept-Ranges', '14.5') content_range = converter( header_getter('Content-Range', '14.16'), parse_content_range, serialize_content_range, 'ContentRange object') date = date_header('Date', '14.18') expires = date_header('Expires', '14.21') last_modified = date_header('Last-Modified', '14.29') _etag_raw = header_getter('ETag', '14.19') etag = converter( _etag_raw, parse_etag_response, serialize_etag_response, 'Entity tag' ) @property def etag_strong(self): return parse_etag_response(self._etag_raw, strong=True) location = header_getter('Location', '14.30') pragma = header_getter('Pragma', '14.32') age = converter( header_getter('Age', '14.6'), parse_int_safe, serialize_int, 'int') retry_after = converter( header_getter('Retry-After', '14.37'), parse_date_delta, serialize_date_delta, 'HTTP date or delta seconds') server = header_getter('Server', '14.38') # TODO: the standard allows this to be a list of challenges www_authenticate = converter( header_getter('WWW-Authenticate', '14.47'), parse_auth, serialize_auth, ) # # charset # def _charset__get(self): """ Get/set the ``charset`` specified in ``Content-Type``. There is no checking to validate that a ``content_type`` actually allows for a ``charset`` parameter. """ header = self.headers.get('Content-Type') if not header: return None match = CHARSET_RE.search(header) if match: return match.group(1) return None def _charset__set(self, charset): if charset is None: self._charset__del() return header = self.headers.get('Content-Type', None) if header is None: raise AttributeError("You cannot set the charset when no " "content-type is defined") match = CHARSET_RE.search(header) if match: header = header[:match.start()] + header[match.end():] header += '; charset=%s' % charset self.headers['Content-Type'] = header def _charset__del(self): header = self.headers.pop('Content-Type', None) if header is None: # Don't need to remove anything return match = CHARSET_RE.search(header) if match: header = header[:match.start()] + header[match.end():] self.headers['Content-Type'] = header charset = property(_charset__get, _charset__set, _charset__del, doc=_charset__get.__doc__) # # content_type # def _content_type__get(self): """ Get/set the ``Content-Type`` header. If no ``Content-Type`` header is set, this will return ``None``. .. versionchanged:: 1.7 Setting a new ``Content-Type`` will remove all ``Content-Type`` parameters and reset the ``charset`` to the default if the ``Content-Type`` is ``text/*`` or XML (``application/xml`` or ``*/*+xml``). To preserve all ``Content-Type`` parameters, you may use the following code: .. code-block:: python resp = Response() params = resp.content_type_params resp.content_type = 'application/something' resp.content_type_params = params """ header = self.headers.get('Content-Type') if not header: return None return header.split(';', 1)[0] def _content_type__set(self, value): if not value: self._content_type__del() return else: if PY2 and isinstance(value, text_type): value = value.encode("latin-1") if not isinstance(value, string_types): raise TypeError("content_type requires value to be of string_types") content_type = value # Set up the charset if the content-type doesn't have one has_charset = 'charset=' in content_type new_charset = None if ( not has_charset and self.default_charset ): new_charset = self.default_charset # Optimize for the default_content_type as shipped by # WebOb, becuase we know that 'text/html' has a charset, # otherwise add a charset if the content_type has a charset. # # We add the default charset if the content-type is "texty". if ( new_charset and ( content_type == 'text/html' or _content_type_has_charset(content_type) ) ): content_type += '; charset=' + new_charset self.headers['Content-Type'] = content_type def _content_type__del(self): self.headers.pop('Content-Type', None) content_type = property(_content_type__get, _content_type__set, _content_type__del, doc=_content_type__get.__doc__) # # content_type_params # def _content_type_params__get(self): """ A dictionary of all the parameters in the content type. (This is not a view, set to change, modifications of the dict will not be applied otherwise.) """ params = self.headers.get('Content-Type', '') if ';' not in params: return {} params = params.split(';', 1)[1] result = {} for match in _PARAM_RE.finditer(params): result[match.group(1)] = match.group(2) or match.group(3) or '' return result def _content_type_params__set(self, value_dict): if not value_dict: self._content_type_params__del() return params = [] for k, v in sorted(value_dict.items()): if not _OK_PARAM_RE.search(v): v = '"%s"' % v.replace('"', '\\"') params.append('; %s=%s' % (k, v)) ct = self.headers.pop('Content-Type', '').split(';', 1)[0] ct += ''.join(params) self.headers['Content-Type'] = ct def _content_type_params__del(self): self.headers['Content-Type'] = self.headers.get( 'Content-Type', '').split(';', 1)[0] content_type_params = property( _content_type_params__get, _content_type_params__set, _content_type_params__del, _content_type_params__get.__doc__ ) # # set_cookie, unset_cookie, delete_cookie, merge_cookies #
[文档] def merge_cookies(self, resp): """Merge the cookies that were set on this response with the given ``resp`` object (which can be any WSGI application). If the ``resp`` is a :class:`webob.Response` object, then the other object will be modified in-place. """ if not self.headers.get('Set-Cookie'): return resp if isinstance(resp, Response): for header in self.headers.getall('Set-Cookie'): resp.headers.add('Set-Cookie', header) return resp else: c_headers = [h for h in self.headerlist if h[0].lower() == 'set-cookie'] def repl_app(environ, start_response): def repl_start_response(status, headers, exc_info=None): return start_response(status, headers + c_headers, exc_info=exc_info) return resp(environ, repl_start_response) return repl_app
# # cache_control # _cache_control_obj = None def _cache_control__get(self): """ Get/set/modify the Cache-Control header (`HTTP spec section 14.9 <http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9>`_). """ value = self.headers.get('cache-control', '') if self._cache_control_obj is None: self._cache_control_obj = CacheControl.parse( value, updates_to=self._update_cache_control, type='response') self._cache_control_obj.header_value = value if self._cache_control_obj.header_value != value: new_obj = CacheControl.parse(value, type='response') self._cache_control_obj.properties.clear() self._cache_control_obj.properties.update(new_obj.properties) self._cache_control_obj.header_value = value return self._cache_control_obj def _cache_control__set(self, value): # This actually becomes a copy if not value: value = "" if isinstance(value, dict): value = CacheControl(value, 'response') if isinstance(value, text_type): value = str(value) if isinstance(value, str): if self._cache_control_obj is None: self.headers['Cache-Control'] = value return value = CacheControl.parse(value, 'response') cache = self.cache_control cache.properties.clear() cache.properties.update(value.properties) def _cache_control__del(self): self.cache_control = {} def _update_cache_control(self, prop_dict): value = serialize_cache_control(prop_dict) if not value: if 'Cache-Control' in self.headers: del self.headers['Cache-Control'] else: self.headers['Cache-Control'] = value cache_control = property( _cache_control__get, _cache_control__set, _cache_control__del, doc=_cache_control__get.__doc__) # # cache_expires # def _cache_expires(self, seconds=0, **kw): """ Set expiration on this request. This sets the response to expire in the given seconds, and any other attributes are used for ``cache_control`` (e.g., ``private=True``). """ if seconds is True: seconds = 0 elif isinstance(seconds, timedelta): seconds = timedelta_to_seconds(seconds) cache_control = self.cache_control if seconds is None: pass elif not seconds: # To really expire something, you have to force a # bunch of these cache control attributes, and IE may # not pay attention to those still so we also set # Expires. cache_control.no_store = True cache_control.no_cache = True cache_control.must_revalidate = True cache_control.max_age = 0 cache_control.post_check = 0 cache_control.pre_check = 0 self.expires = datetime.utcnow() if 'last-modified' not in self.headers: self.last_modified = datetime.utcnow() self.pragma = 'no-cache' else: cache_control.properties.clear() cache_control.max_age = seconds self.expires = datetime.utcnow() + timedelta(seconds=seconds) self.pragma = None for name, value in kw.items(): setattr(cache_control, name, value) cache_expires = property(lambda self: self._cache_expires, _cache_expires) # # encode_content, decode_content, md5_etag #
[文档] def encode_content(self, encoding='gzip', lazy=False): """ Encode the content with the given encoding (only ``gzip`` and ``identity`` are supported). """ assert encoding in ('identity', 'gzip'), \ "Unknown encoding: %r" % encoding if encoding == 'identity': self.decode_content() return if self.content_encoding == 'gzip': return if lazy: self.app_iter = gzip_app_iter(self._app_iter) self.content_length = None else: self.app_iter = list(gzip_app_iter(self._app_iter)) self.content_length = sum(map(len, self._app_iter)) self.content_encoding = 'gzip'
def decode_content(self): content_encoding = self.content_encoding or 'identity' if content_encoding == 'identity': return if content_encoding not in ('gzip', 'deflate'): raise ValueError( "I don't know how to decode the content %s" % content_encoding) if content_encoding == 'gzip': from gzip import GzipFile from io import BytesIO gzip_f = GzipFile(filename='', mode='r', fileobj=BytesIO(self.body)) self.body = gzip_f.read() self.content_encoding = None gzip_f.close() else: # Weird feature: http://bugs.python.org/issue5784 self.body = zlib.decompress(self.body, -15) self.content_encoding = None
[文档] def md5_etag(self, body=None, set_content_md5=False): """ Generate an etag for the response object using an MD5 hash of the body (the ``body`` parameter, or ``self.body`` if not given). Sets ``self.etag``. If ``set_content_md5`` is ``True``, sets ``self.content_md5`` as well. """ if body is None: body = self.body md5_digest = md5(body).digest() md5_digest = b64encode(md5_digest) md5_digest = md5_digest.replace(b'\n', b'') md5_digest = native_(md5_digest) self.etag = md5_digest.strip('=') if set_content_md5: self.content_md5 = md5_digest
@staticmethod def _make_location_absolute(environ, value): if SCHEME_RE.search(value): return value new_location = urlparse.urljoin(_request_uri(environ), value) return new_location def _abs_headerlist(self, environ): # Build the headerlist, if we have a Location header, make it absolute return [ (k, v) if k.lower() != 'location' else (k, self._make_location_absolute(environ, v)) for (k, v) in self._headerlist ] # # __call__, conditional_response_app # def __call__(self, environ, start_response): """ WSGI application interface """ if self.conditional_response: return self.conditional_response_app(environ, start_response) headerlist = self._abs_headerlist(environ) start_response(self.status, headerlist) if environ['REQUEST_METHOD'] == 'HEAD': # Special case here... return EmptyResponse(self._app_iter) return self._app_iter _safe_methods = ('GET', 'HEAD')
[文档] def conditional_response_app(self, environ, start_response): """ Like the normal ``__call__`` interface, but checks conditional headers: * ``If-Modified-Since`` (``304 Not Modified``; only on ``GET``, ``HEAD``) * ``If-None-Match`` (``304 Not Modified``; only on ``GET``, ``HEAD``) * ``Range`` (``406 Partial Content``; only on ``GET``, ``HEAD``) """ req = BaseRequest(environ) headerlist = self._abs_headerlist(environ) method = environ.get('REQUEST_METHOD', 'GET') if method in self._safe_methods: status304 = False if req.if_none_match and self.etag: status304 = self.etag in req.if_none_match elif req.if_modified_since and self.last_modified: status304 = self.last_modified <= req.if_modified_since if status304: start_response('304 Not Modified', filter_headers(headerlist)) return EmptyResponse(self._app_iter) if ( req.range and self in req.if_range and self.content_range is None and method in ('HEAD', 'GET') and self.status_code == 200 and self.content_length is not None ): content_range = req.range.content_range(self.content_length) if content_range is None: iter_close(self._app_iter) body = bytes_("Requested range not satisfiable: %s" % req.range) headerlist = [ ('Content-Length', str(len(body))), ('Content-Range', str(ContentRange(None, None, self.content_length))), ('Content-Type', 'text/plain'), ] + filter_headers(headerlist) start_response('416 Requested Range Not Satisfiable', headerlist) if method == 'HEAD': return () return [body] else: app_iter = self.app_iter_range(content_range.start, content_range.stop) if app_iter is not None: # the following should be guaranteed by # Range.range_for_length(length) assert content_range.start is not None headerlist = [ ('Content-Length', str(content_range.stop - content_range.start)), ('Content-Range', str(content_range)), ] + filter_headers(headerlist, ('content-length',)) start_response('206 Partial Content', headerlist) if method == 'HEAD': return EmptyResponse(app_iter) return app_iter start_response(self.status, headerlist) if method == 'HEAD': return EmptyResponse(self._app_iter) return self._app_iter
[文档] def app_iter_range(self, start, stop): """ Return a new ``app_iter`` built from the response ``app_iter``, that serves up only the given ``start:stop`` range. """ app_iter = self._app_iter if hasattr(app_iter, 'app_iter_range'): return app_iter.app_iter_range(start, stop) return AppIterRange(app_iter, start, stop)
def filter_headers(hlist, remove_headers=('content-length', 'content-type')): return [h for h in hlist if (h[0].lower() not in remove_headers)] def iter_file(file, block_size=1 << 18): # 256Kb while True: data = file.read(block_size) if not data: break yield data class ResponseBodyFile(object): mode = 'wb' closed = False def __init__(self, response): """ Represents a :class:`~Response` as a file like object. """ self.response = response self.write = response.write def __repr__(self): return '<body_file for %r>' % self.response encoding = property( lambda self: self.response.charset, doc="The encoding of the file (inherited from response.charset)" ) def writelines(self, seq): """ Write a sequence of lines to the response. """ for item in seq: self.write(item) def close(self): raise NotImplementedError("Response bodies cannot be closed") def flush(self): pass def tell(self): """ Provide the current location where we are going to start writing. """ if not self.response.has_body: return 0 return sum([len(chunk) for chunk in self.response.app_iter]) class AppIterRange(object): """ Wraps an ``app_iter``, returning just a range of bytes. """ def __init__(self, app_iter, start, stop): assert start >= 0, "Bad start: %r" % start assert stop is None or (stop >= 0 and stop >= start), ( "Bad stop: %r" % stop) self.app_iter = iter(app_iter) self._pos = 0 # position in app_iter self.start = start self.stop = stop def __iter__(self): return self def _skip_start(self): start, stop = self.start, self.stop for chunk in self.app_iter: self._pos += len(chunk) if self._pos < start: continue elif self._pos == start: return b'' else: chunk = chunk[start - self._pos:] if stop is not None and self._pos > stop: chunk = chunk[:stop - self._pos] assert len(chunk) == stop - start return chunk else: raise StopIteration() def next(self): if self._pos < self.start: # need to skip some leading bytes return self._skip_start() stop = self.stop if stop is not None and self._pos >= stop: raise StopIteration chunk = next(self.app_iter) self._pos += len(chunk) if stop is None or self._pos <= stop: return chunk else: return chunk[:stop - self._pos] __next__ = next # py3 def close(self): iter_close(self.app_iter) class EmptyResponse(object): """ An empty WSGI response. An iterator that immediately stops. Optionally provides a close method to close an underlying ``app_iter`` it replaces. """ def __init__(self, app_iter=None): if app_iter is not None and hasattr(app_iter, 'close'): self.close = app_iter.close def __iter__(self): return self def __len__(self): return 0 def next(self): raise StopIteration() __next__ = next # py3 def _is_xml(content_type): return ( content_type.startswith('application/xml') or ( content_type.startswith('application/') and content_type.endswith('+xml') ) or ( content_type.startswith('image/') and content_type.endswith('+xml') ) ) def _content_type_has_charset(content_type): return ( content_type.startswith('text/') or _is_xml(content_type) ) def _request_uri(environ): """Like ``wsgiref.url.request_uri``, except eliminates ``:80`` ports. Returns the full request URI.""" url = environ['wsgi.url_scheme'] + '://' if environ.get('HTTP_HOST'): url += environ['HTTP_HOST'] else: url += environ['SERVER_NAME'] + ':' + environ['SERVER_PORT'] if url.endswith(':80') and environ['wsgi.url_scheme'] == 'http': url = url[:-3] elif url.endswith(':443') and environ['wsgi.url_scheme'] == 'https': url = url[:-4] if PY2: script_name = environ.get('SCRIPT_NAME', '/') path_info = environ.get('PATH_INFO', '') else: script_name = bytes_(environ.get('SCRIPT_NAME', '/'), 'latin-1') path_info = bytes_(environ.get('PATH_INFO', ''), 'latin-1') url += url_quote(script_name) qpath_info = url_quote(path_info) if 'SCRIPT_NAME' not in environ: url += qpath_info[1:] else: url += qpath_info return url def iter_close(iter): if hasattr(iter, 'close'): iter.close() def gzip_app_iter(app_iter): size = 0 crc = zlib.crc32(b"") & 0xffffffff compress = zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS, zlib.DEF_MEM_LEVEL, 0) yield _gzip_header for item in app_iter: size += len(item) crc = zlib.crc32(item, crc) & 0xffffffff # The compress function may return zero length bytes if the input is # small enough; it buffers the input for the next iteration or for a # flush. result = compress.compress(item) if result: yield result # Similarly, flush may also not yield a value. result = compress.flush() if result: yield result yield struct.pack("<2L", crc, size & 0xffffffff) def _error_unicode_in_app_iter(app_iter, body): app_iter_repr = repr(app_iter) if len(app_iter_repr) > 50: app_iter_repr = ( app_iter_repr[:30] + '...' + app_iter_repr[-10:]) raise TypeError( 'An item of the app_iter (%s) was text, causing a ' 'text body: %r' % (app_iter_repr, body))