Fixed #24935 -- Refactored common conditional GET handling.

This commit is contained in:
Denis Cornehl 2015-06-05 14:26:48 +01:00 committed by Tim Graham
parent 1f7b25c1a7
commit 7a40fef17a
4 changed files with 130 additions and 109 deletions

View File

@ -1,4 +1,3 @@
import hashlib
import logging
import re
@ -7,6 +6,7 @@ from django.conf import settings
from django.core import urlresolvers
from django.core.exceptions import PermissionDenied
from django.core.mail import mail_managers
from django.utils.cache import get_conditional_response, set_response_etag
from django.utils.encoding import force_text
logger = logging.getLogger('django.request')
@ -113,20 +113,15 @@ class CommonMiddleware(object):
return self.response_redirect_class(self.get_full_path_with_slash(request))
if settings.USE_ETAGS:
if not response.has_header('ETag'):
set_response_etag(response)
if response.has_header('ETag'):
etag = response['ETag']
elif response.streaming:
etag = None
else:
etag = '"%s"' % hashlib.md5(response.content).hexdigest()
if etag is not None:
if (200 <= response.status_code < 300
and request.META.get('HTTP_IF_NONE_MATCH') == etag):
cookies = response.cookies
response = http.HttpResponseNotModified()
response.cookies = cookies
else:
response['ETag'] = etag
return get_conditional_response(
request,
etag=response['ETag'],
response=response,
)
return response

View File

@ -1,3 +1,4 @@
from django.utils.cache import get_conditional_response
from django.utils.http import http_date, parse_http_date_safe
@ -14,28 +15,17 @@ class ConditionalGetMiddleware(object):
if not response.streaming and not response.has_header('Content-Length'):
response['Content-Length'] = str(len(response.content))
# If-None-Match must be ignored if original result would be anything
# other than a 2XX or 304 status. 304 status would result in no change.
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
if 200 <= response.status_code < 300 and response.has_header('ETag'):
if_none_match = request.META.get('HTTP_IF_NONE_MATCH')
if if_none_match == response['ETag']:
# Setting the status is enough here. The response handling path
# automatically removes content for this status code (in
# http.conditional_content_removal()).
response.status_code = 304
etag = response.get('ETag')
last_modified = response.get('Last-Modified')
if last_modified:
last_modified = parse_http_date_safe(last_modified)
# If-Modified-Since must be ignored if the original result was not a 200.
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.25
if response.status_code == 200 and response.has_header('Last-Modified'):
if_modified_since = request.META.get('HTTP_IF_MODIFIED_SINCE')
if if_modified_since is not None:
if_modified_since = parse_http_date_safe(if_modified_since)
if if_modified_since is not None:
last_modified = parse_http_date_safe(response['Last-Modified'])
if last_modified is not None and last_modified <= if_modified_since:
# Setting the status code is enough here (same reasons as
# above).
response.status_code = 304
if etag or last_modified:
return get_conditional_response(
request,
etag=etag,
last_modified=last_modified,
response=response,
)
return response

View File

@ -19,18 +19,24 @@ An example: i18n middleware would need to distinguish caches by the
from __future__ import unicode_literals
import hashlib
import logging
import re
import time
from django.conf import settings
from django.core.cache import caches
from django.http import HttpResponse, HttpResponseNotModified
from django.utils.encoding import force_bytes, force_text, iri_to_uri
from django.utils.http import http_date
from django.utils.http import (
http_date, parse_etags, parse_http_date_safe, quote_etag,
)
from django.utils.timezone import get_current_timezone_name
from django.utils.translation import get_language
cc_delim_re = re.compile(r'\s*,\s*')
logger = logging.getLogger('django.request')
def patch_cache_control(response, **kwargs):
"""
@ -97,9 +103,99 @@ def get_max_age(response):
pass
def _set_response_etag(response):
def set_response_etag(response):
if not response.streaming:
response['ETag'] = '"%s"' % hashlib.md5(response.content).hexdigest()
response['ETag'] = quote_etag(hashlib.md5(response.content).hexdigest())
return response
def _precondition_failed(request):
logger.warning('Precondition Failed: %s', request.path,
extra={
'status_code': 412,
'request': request,
},
)
return HttpResponse(status=412)
def _not_modified(request, response=None):
if response:
# We need to keep the cookies, see ticket #4994.
cookies = response.cookies
response = HttpResponseNotModified()
response.cookies = cookies
return response
else:
return HttpResponseNotModified()
def get_conditional_response(request, etag=None, last_modified=None, response=None):
# Get HTTP request headers
if_modified_since = request.META.get('HTTP_IF_MODIFIED_SINCE')
if if_modified_since:
if_modified_since = parse_http_date_safe(if_modified_since)
if_unmodified_since = request.META.get('HTTP_IF_UNMODIFIED_SINCE')
if if_unmodified_since:
if_unmodified_since = parse_http_date_safe(if_unmodified_since)
if_none_match = request.META.get('HTTP_IF_NONE_MATCH')
if_match = request.META.get('HTTP_IF_MATCH')
etags = []
if if_none_match or if_match:
# There can be more than one ETag in the request, so we
# consider the list of values.
try:
etags = parse_etags(if_none_match or if_match)
except ValueError:
# In case of an invalid ETag, ignore all ETag headers.
# Apparently Opera sends invalidly quoted headers at times
# (we should be returning a 400 response, but that's a
# little extreme) -- this is bug #10681.
if_none_match = None
if_match = None
# If-None-Match must be ignored if original result would be anything
# other than a 2XX or 304 status. 304 status would result in no change.
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.26
if response and not (200 <= response.status_code < 300):
if_none_match = None
if_match = None
# If-Modified-Since must be ignored if the original result was not a 200.
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.25
if response and response.status_code != 200:
if_modified_since = None
if_unmodified_since = None
if not ((if_match and if_modified_since) or
(if_none_match and if_unmodified_since) or
(if_modified_since and if_unmodified_since) or
(if_match and if_none_match)):
# We only get here if no undefined combinations of headers are
# specified.
if ((if_none_match and (etag in etags or
'*' in etags and etag)) and
(not if_modified_since or
(last_modified and if_modified_since and
last_modified <= if_modified_since))):
if request.method in ('GET', 'HEAD'):
return _not_modified(request, response)
else:
return _precondition_failed(request)
elif (if_match and ((not etag and '*' in etags) or
(etag and etag not in etags) or
(last_modified and if_unmodified_since and
last_modified > if_unmodified_since))):
return _precondition_failed(request)
elif (not if_none_match and request.method in ('GET', 'HEAD') and
last_modified and if_modified_since and
last_modified <= if_modified_since):
return _not_modified(request, response)
elif (not if_match and
last_modified and if_unmodified_since and
last_modified > if_unmodified_since):
return _precondition_failed(request)
return response
@ -119,9 +215,9 @@ def patch_response_headers(response, cache_timeout=None):
cache_timeout = 0 # Can't have max-age negative
if settings.USE_ETAGS and not response.has_header('ETag'):
if hasattr(response, 'render') and callable(response.render):
response.add_post_render_callback(_set_response_etag)
response.add_post_render_callback(set_response_etag)
else:
response = _set_response_etag(response)
response = set_response_etag(response)
if not response.has_header('Last-Modified'):
response['Last-Modified'] = http_date()
if not response.has_header('Expires'):

View File

@ -6,14 +6,11 @@ import logging
from calendar import timegm
from functools import wraps
from django.http import (
HttpResponse, HttpResponseNotAllowed, HttpResponseNotModified,
)
from django.http import HttpResponseNotAllowed
from django.middleware.http import ConditionalGetMiddleware
from django.utils.cache import get_conditional_response
from django.utils.decorators import available_attrs, decorator_from_middleware
from django.utils.http import (
http_date, parse_etags, parse_http_date_safe, quote_etag,
)
from django.utils.http import http_date, quote_etag
conditional_page = decorator_from_middleware(ConditionalGetMiddleware)
@ -56,16 +53,6 @@ require_safe = require_http_methods(["GET", "HEAD"])
require_safe.__doc__ = "Decorator to require that a view only accepts safe methods: GET and HEAD."
def _precondition_failed(request):
logger.warning('Precondition Failed: %s', request.path,
extra={
'status_code': 412,
'request': request
},
)
return HttpResponse(status=412)
def condition(etag_func=None, last_modified_func=None):
"""
Decorator to support conditional retrieval (or change) for a view
@ -91,29 +78,6 @@ def condition(etag_func=None, last_modified_func=None):
def decorator(func):
@wraps(func, assigned=available_attrs(func))
def inner(request, *args, **kwargs):
# Get HTTP request headers
if_modified_since = request.META.get("HTTP_IF_MODIFIED_SINCE")
if if_modified_since:
if_modified_since = parse_http_date_safe(if_modified_since)
if_unmodified_since = request.META.get("HTTP_IF_UNMODIFIED_SINCE")
if if_unmodified_since:
if_unmodified_since = parse_http_date_safe(if_unmodified_since)
if_none_match = request.META.get("HTTP_IF_NONE_MATCH")
if_match = request.META.get("HTTP_IF_MATCH")
etags = []
if if_none_match or if_match:
# There can be more than one ETag in the request, so we
# consider the list of values.
try:
etags = parse_etags(if_none_match or if_match)
except ValueError:
# In case of invalid etag ignore all ETag headers.
# Apparently Opera sends invalidly quoted headers at times
# (we should be returning a 400 response, but that's a
# little extreme) -- this is Django bug #10681.
if_none_match = None
if_match = None
# Compute values (if any) for the requested resource.
def get_last_modified():
if last_modified_func:
@ -124,35 +88,11 @@ def condition(etag_func=None, last_modified_func=None):
res_etag = etag_func(request, *args, **kwargs) if etag_func else None
res_last_modified = get_last_modified()
response = None
if not ((if_match and if_modified_since) or
(if_none_match and if_unmodified_since) or
(if_modified_since and if_unmodified_since) or
(if_match and if_none_match)):
# We only get here if no undefined combinations of headers are
# specified.
if ((if_none_match and (res_etag in etags or
"*" in etags and res_etag)) and
(not if_modified_since or
(res_last_modified and if_modified_since and
res_last_modified <= if_modified_since))):
if request.method in ("GET", "HEAD"):
response = HttpResponseNotModified()
else:
response = _precondition_failed(request)
elif (if_match and ((not res_etag and "*" in etags) or
(res_etag and res_etag not in etags) or
(res_last_modified and if_unmodified_since and
res_last_modified > if_unmodified_since))):
response = _precondition_failed(request)
elif (not if_none_match and request.method in ("GET", "HEAD") and
res_last_modified and if_modified_since and
res_last_modified <= if_modified_since):
response = HttpResponseNotModified()
elif (not if_match and
res_last_modified and if_unmodified_since and
res_last_modified > if_unmodified_since):
response = _precondition_failed(request)
response = get_conditional_response(
request,
etag=res_etag,
last_modified=res_last_modified,
)
if response is None:
response = func(request, *args, **kwargs)