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Fix attempting two pagecache reads in one request

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`c` gets clobbered when transitioning between controllers, so anything
that needs to survive that must be in `request.environ` instead.
This commit is contained in:
Jordan Milne
2014-12-01 17:48:27 -04:00
parent c79a3bde17
commit ab6058e2a1
2 changed files with 23 additions and 14 deletions
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30
r2/r2/controllers/reddit_base.py
View File

@@ -1103,6 +1103,12 @@ class MinimalController(BaseController):
hooks.get_hook("reddit.request.minimal_begin").call()
def can_use_pagecache(self):
# Don't allow using pagecache if redirecting from an endpoint
# that disallowed it (for ex. redirecting from one that caches loggedin
# responses to one that doesn't)
if not request.environ.get("CAN_USE_PAGECACHE", True):
return False
handler = self._get_action_handler()
policy = getattr(handler, "pagecache_policy",
PAGECACHE_POLICY.LOGGEDOUT_ONLY)
@@ -1115,12 +1121,20 @@ class MinimalController(BaseController):
return False
def try_pagecache(self):
c.can_use_pagecache = self.can_use_pagecache()
can_use_pagecache = self.can_use_pagecache()
request.environ["CAN_USE_PAGECACHE"] = can_use_pagecache
if request.method.upper() == 'GET' and c.can_use_pagecache:
c.request_key = self.request_key()
# This guards against checking the pagecache twice and possibly
# modifying the request key when being redirected from one endpoint
# to the other in-request (i.e. when redirected to the error document)
if request.environ.get("TRIED_PAGECACHE", False):
return
request.environ["TRIED_PAGECACHE"] = True
if request.method.upper() == 'GET' and can_use_pagecache:
request.environ["REQUEST_KEY"] = self.request_key()
try:
r = g.pagecache.get(c.request_key)
r = g.pagecache.get(request.environ["REQUEST_KEY"])
except MemcachedError as e:
g.log.warning("pagecache error: %s", e)
return
@@ -1178,15 +1192,15 @@ class MinimalController(BaseController):
# such as If-Modified-Since headers for 304s or requesting IP for 429s.
if (g.page_cache_time
and request.method.upper() == 'GET'
and c.can_use_pagecache
and c.request_key
and request.environ.get("CAN_USE_PAGECACHE", False)
and request.environ.get("REQUEST_KEY", None)
and not c.used_cache
and not would_poison
and response.status_int not in (304, 429)
and not response.status.startswith("5")
and not c.is_exception_response):
try:
g.pagecache.set(c.request_key,
g.pagecache.set(request.environ["REQUEST_KEY"],
(response._current_obj(), c.cookies),
g.page_cache_time)
except MemcachedError as e:
@@ -1198,7 +1212,7 @@ class MinimalController(BaseController):
pragmas = [p.strip() for p in
request.headers.get("Pragma", "").split(",")]
if g.debug or "x-reddit-pagecache" in pragmas:
if c.can_use_pagecache:
if request.environ.get("CAN_USE_PAGECACHE", False):
pagecache_state = "hit" if c.used_cache else "miss"
else:
pagecache_state = "disallowed"

7
r2/r2/lib/base.py
View File

@@ -70,12 +70,7 @@ class BaseController(WSGIController):
def __before__(self):
self.pre()
# This guards against checking the pagecache twice and possibly
# modifying the request key when being redirected from one endpoint
# to the other in-request (i.e. when redirected to the error document)
if not c.tried_pagecache:
c.tried_pagecache = True
self.try_pagecache()
self.try_pagecache()
def __after__(self):
self.post()