class CacheControlAdapter(HTTPAdapter):
invalidating_methods = set(['PUT', 'DELETE'])
def __init__(self, cache=None, *args, **kw):
super(CacheControlAdapter, self).__init__(*args, **kw)
self.cache = cache or DictCache()
self.controller = CacheController(self.cache)
def send(self, request, **kw):
"""Send a request. Use the request information to see if it
exists in the cache.
"""
if request.method == 'GET':
cached_response = self.controller.cached_request(
request.url, request.headers
)
if cached_response:
return cached_response
# check for etags and add headers if appropriate
headers = self.controller.add_headers(request.url)
request.headers.update(headers)
resp = super(CacheControlAdapter, self).send(request, **kw)
return resp
def build_response(self, request, response):
resp = super(CacheControlAdapter, self).build_response(
request, response
)
# See if we should invalidate the cache.
if request.method in self.invalidating_methods and resp.ok:
cache_url = self.controller.cache_url(request.url)
self.cache.delete(cache_url)
# Try to store the response if it is a GET
elif request.method == 'GET':
if response.status == 304:
resp = self.controller.get_cached_response(request)
else:
self.controller.cache_response(request, resp)
print self.controller.cache.data
# Give the request a from_cache attr to let people use it
# rather than testing for hasattr.
if not hasattr(resp, 'from_cache'):
resp.from_cache = False
return resp
