bdceedf303
The socket._fileobject and io.BufferedReader are sometimes used to implement wsgi.input. However, app developers are often burned by the fact that the read() method for these objects block indefinitely if either no size is passed, or a size greater than the request's content length is passed to the method. This patch makes Falcon detect when the above native stream types are used by a WSGI server, and wraps them with a simple Body object that provides more forgiving read, readline, and readlines methods than what is otherwise provided. The end result is that app developers are shielded from this silly inconsistency between WSGI servers. Fixes issue #147
699 lines
24 KiB
Python
699 lines
24 KiB
Python
"""Defines the Request class.
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Copyright 2013 by Rackspace Hosting, Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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"""
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from datetime import datetime
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try:
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# NOTE(kgrifs): In Python 2.6 and 2.7, socket._fileobject is a
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# standard way of exposing a socket as a file-like object, and
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# is used by wsgiref for wsgi.input.
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import socket
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NativeStream = socket._fileobject
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except AttributeError: # pragma nocover
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# NOTE(kgriffs): In Python 3.3, wsgiref implements wsgi.input
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# using _io.BufferedReader which is an alias of io.BufferedReader
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import io
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NativeStream = io.BufferedReader
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import mimeparse
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import six
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from falcon.exceptions import HTTPBadRequest
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from falcon import util
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from falcon import request_helpers as helpers
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DEFAULT_ERROR_LOG_FORMAT = (u'{0:%Y-%m-%d %H:%M:%S} [FALCON] [ERROR]'
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u' {1} {2}{3} => ')
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TRUE_STRINGS = ('true', 'True', 'yes')
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FALSE_STRINGS = ('false', 'False', 'no')
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class InvalidHeaderValueError(HTTPBadRequest):
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def __init__(self, msg, href=None, href_text=None):
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super(InvalidHeaderValueError, self).__init__(
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'Invalid header value', msg, href=href, href_text=None)
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class InvalidParamValueError(HTTPBadRequest):
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def __init__(self, msg, href=None, href_text=None):
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super(InvalidParamValueError, self).__init__(
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'Invalid query parameter', msg, href=href, href_text=None)
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class Request(object):
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"""Represents a client's HTTP request
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Attributes:
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method: HTTP method requested (e.g., GET, POST, etc.)
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path: Path portion of the request URL (not including query string).
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query_string: Query string portion of the request URL, without
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the preceding '?' character.
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stream: Stream-like object for reading the body of the request, if any.
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"""
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__slots__ = (
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'env',
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'_headers',
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'method',
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'_params',
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'path',
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'query_string',
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'stream',
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'_wsgierrors'
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)
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def __init__(self, env):
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"""Initialize attributes based on a WSGI environment dict
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Note: Request is not meant to be instantiated directory by responders.
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Args:
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env: A WSGI environment dict passed in from the server. See also
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the PEP-3333 spec.
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"""
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self.env = env
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self._wsgierrors = env['wsgi.errors']
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self.stream = env['wsgi.input']
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self.method = env['REQUEST_METHOD']
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# Normalize path
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path = env['PATH_INFO']
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if path:
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if len(path) != 1 and path.endswith('/'):
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self.path = path[:-1]
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else:
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self.path = path
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else:
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self.path = '/'
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# QUERY_STRING isn't required to be in env, so let's check
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# PERF: if...in is faster than using env.get(...)
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if 'QUERY_STRING' in env:
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self.query_string = env['QUERY_STRING']
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else:
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self.query_string = ''
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# PERF: Don't parse it if we don't have to!
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if self.query_string:
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self._params = helpers.parse_query_string(self.query_string)
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else:
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self._params = {}
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self._headers = helpers.parse_headers(env)
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# NOTE(kgriffs): Wrap wsgi.input if needed to make read() more robust,
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# normalizing semantics between, e.g., gunicorn and wsgiref.
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if isinstance(self.stream, NativeStream): # pragma: nocover
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# NOTE(kgriffs): coverage can't detect that this *is* actually
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# covered since the test that does so uses multiprocessing.
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self.stream = helpers.Body(self.stream, self.content_length)
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# TODO(kgriffs): Use the nocover pragma only for the six.PY3 if..else
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def log_error(self, message): # pragma: no cover
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"""Log an error to wsgi.error
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Prepends timestamp and request info to message, and writes the
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result out to the WSGI server's error stream (wsgi.error).
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Args:
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message: A string describing the problem. If a byte-string it is
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simply written out as-is. Unicode strings will be converted
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to UTF-8.
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"""
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if self.query_string:
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query_string_formatted = '?' + self.query_string
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else:
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query_string_formatted = ''
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log_line = (
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DEFAULT_ERROR_LOG_FORMAT.
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format(datetime.now(), self.method, self.path,
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query_string_formatted)
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)
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if six.PY3:
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self._wsgierrors.write(log_line + message + '\n')
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else:
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if isinstance(message, unicode):
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message = message.encode('utf-8')
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self._wsgierrors.write(log_line.encode('utf-8'))
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self._wsgierrors.write(message + '\n')
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@property
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def client_accepts_json(self):
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"""Return True if the Accept header indicates JSON support."""
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return self.client_accepts('application/json')
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@property
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def client_accepts_xml(self):
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"""Return True if the Accept header indicates XML support."""
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return self.client_accepts('application/xml')
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def client_accepts(self, media_type):
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"""Returns the client's preferred media type.
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Args:
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media_type: Media type to check
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Returns:
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True IFF the client has indicated in the Accept header that
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they accept at least one of the specified media types.
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"""
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accept = self.accept
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# PERF(kgriffs): Usually the following will be true, so
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# try it first.
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if (accept == media_type) or (accept == '*/*'):
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return True
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# Fall back to full-blown parsing
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try:
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return mimeparse.quality(media_type, accept) != 0.0
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except ValueError:
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return False
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def client_prefers(self, media_types):
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"""Returns the client's preferred media type given several choices.
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Args:
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media_types: One or more media types from which to choose the
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client's preferred type. This value MUST be an iterable
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collection of strings.
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Returns:
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The client's preferred media type, based on the Accept header,
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or None if the client does not accept any of the specified
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types.
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"""
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try:
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# NOTE(kgriffs): best_match will return '' if no match is found
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preferred_type = mimeparse.best_match(media_types, self.accept)
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except ValueError:
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# Value for the accept header was not formatted correctly
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preferred_type = ''
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return (preferred_type if preferred_type else None)
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@property
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def accept(self):
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"""Value of the Accept header, or */* if not found per RFC."""
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accept = self._get_header_by_wsgi_name('ACCEPT')
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# NOTE(kgriffs): Per RFC, missing accept header is
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# equivalent to '*/*'
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return '*/*' if accept is None else accept
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@property
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def app(self):
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"""Name of the WSGI app (if using WSGI's notion of virtual hosting)."""
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return self.env['SCRIPT_NAME']
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@property
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def auth(self):
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"""Value of the Authorization header, or None if not found."""
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return self._get_header_by_wsgi_name('AUTHORIZATION')
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@property
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def content_length(self):
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"""Value of the Content-Length header
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Returns:
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Value converted to an int, or None if missing.
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Raises:
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HTTPBadRequest: The header had a value, but it wasn't
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formatted correctly or was a negative number.
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"""
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value = self._get_header_by_wsgi_name('CONTENT_LENGTH')
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if value:
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try:
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value_as_int = int(value)
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except ValueError:
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msg = ('The value of the content-length header must be '
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'a number.')
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raise InvalidHeaderValueError(msg)
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if value_as_int < 0:
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msg = ('The value of the content-length header must be '
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'a positive number.')
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raise InvalidHeaderValueError(msg)
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else:
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return value_as_int
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# implicit return None
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@property
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def content_type(self):
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"""Value of the Content-Type header, or None if not found."""
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return self._get_header_by_wsgi_name('CONTENT_TYPE')
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@property
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def date(self):
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"""Value of the Date header, converted to a datetime instance.
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Returns:
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An instance of datetime.datetime representing the value of
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the Date header, or None if the Date header is not present
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in the request.
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Raises:
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HTTPBadRequest: The date value could not be parsed, likely
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because it does not confrom to RFC 1123.
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"""
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http_date = self._get_header_by_wsgi_name('DATE')
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try:
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return util.http_date_to_dt(http_date)
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except ValueError:
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msg = ('The value of the Date header could not be parsed. It '
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'must be formatted according to RFC 1123.')
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raise InvalidHeaderValueError(msg)
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@property
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def expect(self):
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"""Value of the Expect header, or None if missing."""
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return self._get_header_by_wsgi_name('EXPECT')
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@property
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def if_match(self):
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"""Value of the If-Match header, or None if missing."""
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return self._get_header_by_wsgi_name('IF_MATCH')
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@property
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def if_none_match(self):
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"""Value of the If-None-Match header, or None if missing."""
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return self._get_header_by_wsgi_name('IF_NONE_MATCH')
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@property
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def if_modified_since(self):
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"""Value of the If-Modified-Since header, or None if missing."""
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return self._get_header_by_wsgi_name('IF_MODIFIED_SINCE')
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@property
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def if_unmodified_since(self):
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"""Value of the If-Unmodified-Since header, or None if missing."""
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return self._get_header_by_wsgi_name('IF_UNMODIFIED_SINCE')
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@property
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def if_range(self):
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"""Value of the If-Range header, or None if missing."""
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return self._get_header_by_wsgi_name('IF_RANGE')
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@property
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def protocol(self):
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"""Will be either 'http' or 'https'."""
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return self.env['wsgi.url_scheme']
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@property
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def range(self):
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"""A 2-member tuple representing the value of the Range header.
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The two members correspond to first and last byte positions of the
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requested resource, inclusive. Negative indices indicate offset
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from the end of the resource, where -1 is the last byte, -2 is the
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second-to-last byte, and so forth.
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Only continous ranges are supported (e.g., "bytes=0-0,-1" would
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result in an HTTPBadRequest exception.)
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Returns:
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Parse range value, or None if the header is not present.
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Raises:
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HTTPBadRequest: The header had a value, but it wasn't
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formatted correctly.
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"""
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value = self._get_header_by_wsgi_name('RANGE')
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if value:
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if ',' in value:
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raise InvalidHeaderValueError('Only continuous byte ranges '
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'are supported.')
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try:
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first, last = value.split('-')
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if first:
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return (int(first), int(last or -1))
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elif last:
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return (-int(last), -1)
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else:
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raise InvalidHeaderValueError(
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'Range value is missing offsets')
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except ValueError:
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href = 'http://goo.gl/zZ6Ey'
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href_text = 'HTTP/1.1 Range Requests'
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raise InvalidHeaderValueError('Range string must be formatted '
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'according to RFC 2616.',
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href=href,
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href_text=href_text)
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# implicit return None
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@property
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def uri(self):
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"""The fully-qualified URI for the request."""
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# PERF: For small numbers of items, '+' is faster than ''.join(...)
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value = (self.protocol + '://' +
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self.get_header('host') +
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self.app +
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self.path)
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if self.query_string:
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value = value + '?' + self.query_string
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return value
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url = uri
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"""Alias for uri"""
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@property
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def relative_uri(self):
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"""The path + query string portion of the full URI."""
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if self.query_string:
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return self.app + self.path + '?' + self.query_string
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return self.app + self.path
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@property
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def user_agent(self):
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"""Value of the User-Agent string, or None if missing."""
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return self._get_header_by_wsgi_name('USER_AGENT')
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@property
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def headers(self):
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"""Get HTTP headers
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Build a temporary dictionary of dash-separated HTTP headers,
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which can be used as a whole, like, to perform an HTTP request.
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If you want to lookup a header, please use `get_header` instead.
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Returns:
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A dictionary of HTTP headers.
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"""
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return dict((k.lower().replace('_', '-'), v)
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for k, v in self._headers.items())
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def get_header(self, name, required=False):
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"""Return a header value as a string
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Args:
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name: Header name, case-insensitive (e.g., 'Content-Type')
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required: Set to True to raise HttpBadRequest instead
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of returning gracefully when the header is not found
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(default False)
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Returns:
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The value of the specified header if it exists, or None if the
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header is not found and is not required.
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Raises:
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HTTPBadRequest: The header was not found in the request, but
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it was required.
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"""
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# Use try..except to optimize for the header existing in most cases
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try:
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# Don't take the time to cache beforehand, using HTTP naming.
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# This will be faster, assuming that most headers are looked
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# up only once, and not all headers will be requested.
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return self._headers[name.upper().replace('-', '_')]
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except KeyError:
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if not required:
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return None
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description = 'The "' + name + '" header is required.'
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raise HTTPBadRequest('Missing header', description)
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def get_param(self, name, required=False, store=None):
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"""Return the value of a query string parameter as a string
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Args:
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name: Parameter name, case-sensitive (e.g., 'sort')
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required: Set to True to raise HTTPBadRequest instead of returning
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gracefully when the parameter is not found (default False)
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store: A dict-like object in which to place the value of the
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param, but only if the param is found.
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Returns:
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The value of the param as a string, or None if param is not found
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and is not required.
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Raises:
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HTTPBadRequest: The param was not found in the request, but was
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required.
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"""
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# PERF: Use if..in since it is a good all-around performer; we don't
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# know how likely params are to be specified by clients.
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if name in self._params:
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if store is not None:
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store[name] = self._params[name]
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return self._params[name]
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if not required:
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return None
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description = 'The "' + name + '" query parameter is required.'
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raise HTTPBadRequest('Missing query parameter', description)
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def get_param_as_int(self, name,
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required=False, min=None, max=None, store=None):
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"""Return the value of a query string parameter as an int
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Args:
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name: Parameter name, case-sensitive (e.g., 'limit')
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required: Set to True to raise HTTPBadRequest instead of returning
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gracefully when the parameter is not found or is not an
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integer (default False)
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min: Set to the minimum value allowed for this param. If the param
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is found and it is less than min, an HTTPError is raised.
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max: Set to the maximum value allowed for this param. If the param
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is found and its value is greater than max, an HTTPError is
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raised.
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store: A dict-like object in which to place the value of the
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param, but only if the param is found (default None)
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Returns:
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The value of the param if it is found and can be converted to an
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integer. If the param is not found, returns None, unless required
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is True.
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Raises
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HTTPBadRequest: The param was not found in the request, even though
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it was required to be there. Also raised if the param's value
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falls outside the given interval, i.e., the value must be in
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the interval: min <= value <= max to avoid triggering an error.
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"""
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# PERF: Use if..in since it is a good all-around performer; we don't
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# know how likely params are to be specified by clients.
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if name in self._params:
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val = self._params[name]
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try:
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val = int(val)
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except ValueError:
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description = ('The value of the "' + name + '" query '
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'parameter must be an integer.')
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raise InvalidParamValueError(description)
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if min is not None and val < min:
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description = ('The value of the "' + name + '" query '
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'parameter must be at least %d') % min
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raise InvalidHeaderValueError(description)
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if max is not None and max < val:
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description = ('The value of the "' + name + '" query '
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'parameter may not exceed %d') % max
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raise InvalidHeaderValueError(description)
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if store is not None:
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store[name] = val
|
|
|
|
return val
|
|
|
|
if not required:
|
|
return None
|
|
|
|
description = 'The "' + name + '" query parameter is required.'
|
|
raise HTTPBadRequest('Missing query parameter', description)
|
|
|
|
def get_param_as_bool(self, name, required=False, store=None):
|
|
"""Return the value of a query string parameter as a boolean
|
|
|
|
The following bool-ish strings are supported:
|
|
|
|
True: ('true', 'True', 'yes')
|
|
False: ('false', 'False', 'no')
|
|
|
|
Args:
|
|
name: Parameter name, case-sensitive (e.g., 'limit')
|
|
required: Set to True to raise HTTPBadRequest instead of returning
|
|
gracefully when the parameter is not found or is not a
|
|
recognized bool-ish string (default False).
|
|
store: A dict-like object in which to place the value of the
|
|
param, but only if the param is found (default None)
|
|
|
|
Returns:
|
|
The value of the param if it is found and can be converted to a
|
|
boolean. If the param is not found,
|
|
returns None unless required is True
|
|
|
|
Raises
|
|
HTTPBadRequest: The param was not found in the request, even though
|
|
it was required to be there.
|
|
|
|
"""
|
|
|
|
# PERF: Use if..in since it is a good all-around performer; we don't
|
|
# know how likely params are to be specified by clients.
|
|
if name in self._params:
|
|
val = self._params[name]
|
|
if val in TRUE_STRINGS:
|
|
val = True
|
|
elif val in FALSE_STRINGS:
|
|
val = False
|
|
else:
|
|
description = ('The value of the "' + name + '" query '
|
|
'parameter must be "true" or "false".')
|
|
raise InvalidParamValueError(description)
|
|
|
|
if store is not None:
|
|
store[name] = val
|
|
|
|
return val
|
|
|
|
if not required:
|
|
return None
|
|
|
|
description = 'The "' + name + '" query parameter is required.'
|
|
raise HTTPBadRequest('Missing query parameter', description)
|
|
|
|
def get_param_as_list(self, name,
|
|
transform=None, required=False, store=None):
|
|
"""Return the value of a query string parameter as a list
|
|
|
|
Note that list items must be comma-separated.
|
|
|
|
Args:
|
|
name: Parameter name, case-sensitive (e.g., 'limit')
|
|
transform: An optional transform function that takes as input
|
|
each element in the list as a string and outputs a transformed
|
|
element for inclusion in the list that will be returned. For
|
|
example, passing the int function will transform list items
|
|
into numbers.
|
|
required: Set to True to raise HTTPBadRequest instead of returning
|
|
gracefully when the parameter is not found or is not an
|
|
integer (default False)
|
|
store: A dict-like object in which to place the value of the
|
|
param, but only if the param is found (default None)
|
|
|
|
Returns:
|
|
The value of the param if it is found. Otherwise, returns None
|
|
unless required is True. for partial lists, None will be returned
|
|
as a placeholder. For example:
|
|
|
|
things=1,,3
|
|
|
|
would be returned as:
|
|
|
|
['1', None, '3']
|
|
|
|
while this:
|
|
|
|
things=,,,
|
|
|
|
would just be retured as:
|
|
|
|
[None, None, None, None]
|
|
|
|
Raises
|
|
HTTPBadRequest: The param was not found in the request, but was
|
|
required.
|
|
"""
|
|
|
|
# PERF: Use if..in since it is a good all-around performer; we don't
|
|
# know how likely params are to be specified by clients.
|
|
if name in self._params:
|
|
items = self._params[name].split(',')
|
|
|
|
# PERF(kgriffs): Use if-else rather than a DRY approach
|
|
# that sets transform to a passthrough function; avoids
|
|
# function calling overhead.
|
|
if transform is None:
|
|
items = [i if i != '' else None
|
|
for i in items]
|
|
else:
|
|
try:
|
|
items = [transform(i) if i != '' else None
|
|
for i in items]
|
|
except ValueError:
|
|
desc = ('The value of the "' + name + '" query parameter '
|
|
'is not formatted correctly.')
|
|
raise InvalidParamValueError(desc)
|
|
|
|
if store is not None:
|
|
store[name] = items
|
|
|
|
return items
|
|
|
|
if not required:
|
|
return None
|
|
|
|
raise HTTPBadRequest('Missing query parameter',
|
|
'The "' + name + '" query parameter is required.')
|
|
|
|
# -------------------------------------------------------------------------
|
|
# Helpers
|
|
# -------------------------------------------------------------------------
|
|
|
|
def _get_header_by_wsgi_name(self, name):
|
|
"""Looks up a header, assuming name is already UPPERCASE_UNDERSCORE
|
|
|
|
Args:
|
|
name: Name of the header, already uppercased, and underscored
|
|
|
|
Returns:
|
|
Value of the specified header, or None if the header was not
|
|
found. Also returns None if the value of the header was blank.
|
|
|
|
"""
|
|
try:
|
|
return self._headers[name] or None
|
|
except KeyError:
|
|
return None
|