You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
133 lines
4.7 KiB
133 lines
4.7 KiB
import types
|
|
import functools
|
|
import zlib
|
|
|
|
from requests.adapters import HTTPAdapter
|
|
|
|
from .controller import CacheController
|
|
from .cache import DictCache
|
|
from .filewrapper import CallbackFileWrapper
|
|
|
|
|
|
class CacheControlAdapter(HTTPAdapter):
|
|
invalidating_methods = {"PUT", "DELETE"}
|
|
|
|
def __init__(
|
|
self,
|
|
cache=None,
|
|
cache_etags=True,
|
|
controller_class=None,
|
|
serializer=None,
|
|
heuristic=None,
|
|
cacheable_methods=None,
|
|
*args,
|
|
**kw
|
|
):
|
|
super(CacheControlAdapter, self).__init__(*args, **kw)
|
|
self.cache = cache or DictCache()
|
|
self.heuristic = heuristic
|
|
self.cacheable_methods = cacheable_methods or ("GET",)
|
|
|
|
controller_factory = controller_class or CacheController
|
|
self.controller = controller_factory(
|
|
self.cache, cache_etags=cache_etags, serializer=serializer
|
|
)
|
|
|
|
def send(self, request, cacheable_methods=None, **kw):
|
|
"""
|
|
Send a request. Use the request information to see if it
|
|
exists in the cache and cache the response if we need to and can.
|
|
"""
|
|
cacheable = cacheable_methods or self.cacheable_methods
|
|
if request.method in cacheable:
|
|
try:
|
|
cached_response = self.controller.cached_request(request)
|
|
except zlib.error:
|
|
cached_response = None
|
|
if cached_response:
|
|
return self.build_response(request, cached_response, from_cache=True)
|
|
|
|
# check for etags and add headers if appropriate
|
|
request.headers.update(self.controller.conditional_headers(request))
|
|
|
|
resp = super(CacheControlAdapter, self).send(request, **kw)
|
|
|
|
return resp
|
|
|
|
def build_response(
|
|
self, request, response, from_cache=False, cacheable_methods=None
|
|
):
|
|
"""
|
|
Build a response by making a request or using the cache.
|
|
|
|
This will end up calling send and returning a potentially
|
|
cached response
|
|
"""
|
|
cacheable = cacheable_methods or self.cacheable_methods
|
|
if not from_cache and request.method in cacheable:
|
|
# Check for any heuristics that might update headers
|
|
# before trying to cache.
|
|
if self.heuristic:
|
|
response = self.heuristic.apply(response)
|
|
|
|
# apply any expiration heuristics
|
|
if response.status == 304:
|
|
# We must have sent an ETag request. This could mean
|
|
# that we've been expired already or that we simply
|
|
# have an etag. In either case, we want to try and
|
|
# update the cache if that is the case.
|
|
cached_response = self.controller.update_cached_response(
|
|
request, response
|
|
)
|
|
|
|
if cached_response is not response:
|
|
from_cache = True
|
|
|
|
# We are done with the server response, read a
|
|
# possible response body (compliant servers will
|
|
# not return one, but we cannot be 100% sure) and
|
|
# release the connection back to the pool.
|
|
response.read(decode_content=False)
|
|
response.release_conn()
|
|
|
|
response = cached_response
|
|
|
|
# We always cache the 301 responses
|
|
elif response.status == 301:
|
|
self.controller.cache_response(request, response)
|
|
else:
|
|
# Wrap the response file with a wrapper that will cache the
|
|
# response when the stream has been consumed.
|
|
response._fp = CallbackFileWrapper(
|
|
response._fp,
|
|
functools.partial(
|
|
self.controller.cache_response, request, response
|
|
),
|
|
)
|
|
if response.chunked:
|
|
super_update_chunk_length = response._update_chunk_length
|
|
|
|
def _update_chunk_length(self):
|
|
super_update_chunk_length()
|
|
if self.chunk_left == 0:
|
|
self._fp._close()
|
|
|
|
response._update_chunk_length = types.MethodType(
|
|
_update_chunk_length, 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)
|
|
|
|
# Give the request a from_cache attr to let people use it
|
|
resp.from_cache = from_cache
|
|
|
|
return resp
|
|
|
|
def close(self):
|
|
self.cache.close()
|
|
super(CacheControlAdapter, self).close()
|