你可以用多种方式来实现，这里有几个例子。一个是使用基于WebOb的WSGI中间件（在安装Pyramid时自动安装），另一个是使用Pyramid的event mechanism。
"""
restricting execution based on request body size
"""
from pyramid.config import Configurator
from pyramid.view import view_config
from pyramid.events import NewRequest, subscriber
from webob import Response, Request
from webob.exc import HTTPBadRequest
import unittest
def restrict_body_middleware(app, max_size=0):
"""
this is straight wsgi middleware and in this case only depends on
webob. this can be used with any wsgi compliant web
framework(which is pretty much all of them)
"""
def m(environ, start_response):
r = Request(environ)
if r.content_length <= max_size:
return r.get_response(app)(environ, start_response)
else:
err_body = """
request content_length(%s) exceeds
the configured maximum content_length allowed(%s)
""" % (r.content_length, max_size)
res = HTTPBadRequest(err_body)
return res(environ, start_response)
return m
def new_request_restrict(event):
"""
pyramid event handler called whenever there is a new request
recieved
http://docs.pylonsproject.org/projects/pyramid/en/1.2-branch/narr/events.html
"""
request = event.request
if request.content_length >= 0:
raise HTTPBadRequest("too big")
@view_config()
def index(request):
return Response("HI THERE")
def make_application():
"""
make appplication with one view
"""
config = Configurator()
config.scan()
return config.make_wsgi_app()
def make_application_with_event():
"""
make application with one view and one event subsriber subscribed
to NewRequest
"""
config = Configurator()
config.add_subscriber(new_request_restrict, NewRequest)
return config.make_wsgi_app()
def make_application_with_middleware():
"""
make application with one view wrapped in wsgi middleware
"""
return restrict_body_middleware(make_application())
class TestWSGIApplication(unittest.TestCase):
def testNoRestriction(self):
app = make_application()
request = Request.blank("/", body="i am a request with a body")
self.assert_(request.content_length > 0, "content_length should be > 0")
response = request.get_response(app)
self.assert_(response.status_int == 200, "expected status code 200 got %s" % response.status_int)
def testRestrictedByMiddleware(self):
app = make_application_with_middleware()
request = Request.blank("/", body="i am a request with a body")
self.assert_(request.content_length > 0, "content_length should be > 0")
response = request.get_response(app)
self.assert_(response.status_int == 400, "expected status code 400 got %s" % response.status_int)
def testRestrictedByEvent(self):
app = make_application_with_event()
request = Request.blank("/", body="i am a request with a body")
self.assert_(request.content_length > 0, "content_length should be > 0")
response = request.get_response(app)
self.assert_(response.status_int == 400, "expected status code 400 got %s" % response.status_int)
if __name__ == "__main__":
unittest.main()