From 78250ca9b638bf71be579dfc5fc40b9a2d96f711 Mon Sep 17 00:00:00 2001
From: Helmut Grohne <helmut@subdivi.de>
Date: Thu, 15 Mar 2012 15:13:28 +0100
Subject: middlewares: support multiple start_response calls
Previously middlewares mostly gave up and acted as pass through when a
second start_response call occurred. Now they try to handle this
situation.
---
wsgitools/middlewares.py | 62 ++++++++++++++++++++++++++----------------------
1 file changed, 34 insertions(+), 28 deletions(-)
(limited to 'wsgitools')
diff --git a/wsgitools/middlewares.py b/wsgitools/middlewares.py
index fa2de2e..9792089 100644
--- a/wsgitools/middlewares.py
+++ b/wsgitools/middlewares.py
@@ -143,45 +143,49 @@ class ContentLengthMiddleware:
"""wsgi interface"""
assert isinstance(environ, dict)
todo = []
+ gotdata = False
def modified_start_response(status, headers, exc_info=None):
+ try:
+ if gotdata:
+ assert exc_info is not None
+ raise exc_info[0], exc_info[1], exc_info[2]
+ finally:
+ exc_info = None
assert isinstance(status, str)
assert isinstance(headers, list)
- if (exc_info is not None or
- [v for h, v in headers if h.lower() == "content-length"]):
- todo[:] = (None,)
- return start_response(status, headers, exc_info)
- else:
- todo[:] = ((status, headers),)
- def raise_not_imp(*args):
- raise NotImplementedError
- return raise_not_imp
+ todo[:] = ((status, headers),)
+ def raise_not_imp(*args):
+ raise NotImplementedError
+ return raise_not_imp
ret = self.app(environ, modified_start_response)
assert hasattr(ret, "__iter__")
- if todo and todo[0] is None: # nothing to do
- #print "content-length: nothing"
- return ret
-
if isinstance(ret, list):
- #print "content-length: simple"
+ gotdata = True
+ assert bool(todo)
status, headers = todo[0]
- length = sum(map(len, ret))
- headers.append(("Content-length", str(length)))
+ if not [k for k, _ in headers if k.lower() == "content-length"]:
+ length = sum(map(len, ret))
+ headers.append(("Content-Length", str(length)))
start_response(status, headers)
return ret
ret = iter(ret)
+ first = ""
stopped = False
- data = CloseableList(getattr(ret, "close", None))
- length = 0
- try:
- data.append(next(ret)) # fills todo
- length += len(data[-1])
- except StopIteration:
- stopped = True
-
+ while not (first or stopped):
+ try:
+ first = next(ret)
+ except StopIteration:
+ stopped = True
+ gotdata = True
+ assert bool(todo)
status, headers = todo[0]
+ data = CloseableList(getattr(ret, "close", None))
+ if first:
+ data.append(first)
+ length = len(first)
while (not stopped) and length < self.maxstore:
try:
@@ -191,12 +195,10 @@ class ContentLengthMiddleware:
stopped = True
if stopped:
- #print "content-length: gathered"
headers.append(("Content-length", str(length)))
start_response(status, headers)
return data
- #print "content-length: passthrough"
start_response(status, headers)
return CloseableIterator(getattr(ret, "close", None), data, ret)
@@ -276,10 +278,14 @@ class CachingMiddleware:
del self.cache[path]
cache_object = [now, "", [], []]
def modified_start_respesponse(status, headers, exc_info=None):
+ try:
+ if cache_object[3]:
+ assert exc_info is not None
+ raise exc_info[0], exc_info[1], exc_info[2]
+ finally:
+ exc_info = None
assert isinstance(status, str)
assert isinstance(headers, list)
- if exc_info is not None:
- return self.app(status, headers, exc_info)
cache_object[1] = status
cache_object[2] = headers
write = start_response(status, list(headers))
--
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