Add python venv
This commit is contained in:
Isaac Shoebottom
@ -0,0 +1,11 @@
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"""CacheControl import Interface.
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Make it easy to import from cachecontrol without long namespaces.
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"""
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__author__ = "Eric Larson"
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__email__ = "eric@ionrock.org"
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__version__ = "0.12.6"
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from .wrapper import CacheControl
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from .adapter import CacheControlAdapter
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from .controller import CacheController
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@ -0,0 +1,57 @@
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import logging
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from pip._vendor import requests
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from pip._vendor.cachecontrol.adapter import CacheControlAdapter
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from pip._vendor.cachecontrol.cache import DictCache
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from pip._vendor.cachecontrol.controller import logger
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from argparse import ArgumentParser
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def setup_logging():
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logger.setLevel(logging.DEBUG)
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handler = logging.StreamHandler()
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logger.addHandler(handler)
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def get_session():
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adapter = CacheControlAdapter(
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DictCache(), cache_etags=True, serializer=None, heuristic=None
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)
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sess = requests.Session()
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sess.mount("http://", adapter)
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sess.mount("https://", adapter)
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sess.cache_controller = adapter.controller
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return sess
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def get_args():
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parser = ArgumentParser()
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parser.add_argument("url", help="The URL to try and cache")
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return parser.parse_args()
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def main(args=None):
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args = get_args()
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sess = get_session()
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# Make a request to get a response
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resp = sess.get(args.url)
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# Turn on logging
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setup_logging()
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# try setting the cache
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sess.cache_controller.cache_response(resp.request, resp.raw)
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# Now try to get it
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if sess.cache_controller.cached_request(resp.request):
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print("Cached!")
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else:
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print("Not cached :(")
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if __name__ == "__main__":
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main()
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@ -0,0 +1,133 @@
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import types
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import functools
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import zlib
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from pip._vendor.requests.adapters import HTTPAdapter
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from .controller import CacheController
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from .cache import DictCache
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from .filewrapper import CallbackFileWrapper
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class CacheControlAdapter(HTTPAdapter):
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invalidating_methods = {"PUT", "DELETE"}
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def __init__(
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self,
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cache=None,
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cache_etags=True,
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controller_class=None,
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serializer=None,
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heuristic=None,
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cacheable_methods=None,
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*args,
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**kw
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):
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super(CacheControlAdapter, self).__init__(*args, **kw)
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self.cache = DictCache() if cache is None else cache
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self.heuristic = heuristic
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self.cacheable_methods = cacheable_methods or ("GET",)
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controller_factory = controller_class or CacheController
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self.controller = controller_factory(
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self.cache, cache_etags=cache_etags, serializer=serializer
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)
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def send(self, request, cacheable_methods=None, **kw):
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"""
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Send a request. Use the request information to see if it
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exists in the cache and cache the response if we need to and can.
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"""
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cacheable = cacheable_methods or self.cacheable_methods
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if request.method in cacheable:
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try:
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cached_response = self.controller.cached_request(request)
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except zlib.error:
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cached_response = None
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if cached_response:
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return self.build_response(request, cached_response, from_cache=True)
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# check for etags and add headers if appropriate
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request.headers.update(self.controller.conditional_headers(request))
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resp = super(CacheControlAdapter, self).send(request, **kw)
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return resp
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def build_response(
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self, request, response, from_cache=False, cacheable_methods=None
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):
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"""
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Build a response by making a request or using the cache.
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This will end up calling send and returning a potentially
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cached response
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"""
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cacheable = cacheable_methods or self.cacheable_methods
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if not from_cache and request.method in cacheable:
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# Check for any heuristics that might update headers
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# before trying to cache.
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if self.heuristic:
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response = self.heuristic.apply(response)
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# apply any expiration heuristics
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if response.status == 304:
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# We must have sent an ETag request. This could mean
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# that we've been expired already or that we simply
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# have an etag. In either case, we want to try and
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# update the cache if that is the case.
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cached_response = self.controller.update_cached_response(
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request, response
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)
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if cached_response is not response:
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from_cache = True
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# We are done with the server response, read a
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# possible response body (compliant servers will
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# not return one, but we cannot be 100% sure) and
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# release the connection back to the pool.
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response.read(decode_content=False)
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response.release_conn()
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response = cached_response
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# We always cache the 301 responses
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elif response.status == 301:
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self.controller.cache_response(request, response)
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else:
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# Wrap the response file with a wrapper that will cache the
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# response when the stream has been consumed.
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response._fp = CallbackFileWrapper(
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response._fp,
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functools.partial(
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self.controller.cache_response, request, response
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),
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)
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if response.chunked:
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super_update_chunk_length = response._update_chunk_length
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def _update_chunk_length(self):
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super_update_chunk_length()
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if self.chunk_left == 0:
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self._fp._close()
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response._update_chunk_length = types.MethodType(
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_update_chunk_length, response
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)
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resp = super(CacheControlAdapter, self).build_response(request, response)
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# See if we should invalidate the cache.
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if request.method in self.invalidating_methods and resp.ok:
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cache_url = self.controller.cache_url(request.url)
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self.cache.delete(cache_url)
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# Give the request a from_cache attr to let people use it
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resp.from_cache = from_cache
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return resp
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def close(self):
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self.cache.close()
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super(CacheControlAdapter, self).close()
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@ -0,0 +1,39 @@
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"""
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The cache object API for implementing caches. The default is a thread
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safe in-memory dictionary.
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"""
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from threading import Lock
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class BaseCache(object):
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def get(self, key):
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raise NotImplementedError()
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def set(self, key, value):
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raise NotImplementedError()
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def delete(self, key):
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raise NotImplementedError()
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def close(self):
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pass
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class DictCache(BaseCache):
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def __init__(self, init_dict=None):
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self.lock = Lock()
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self.data = init_dict or {}
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def get(self, key):
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return self.data.get(key, None)
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def set(self, key, value):
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with self.lock:
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self.data.update({key: value})
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def delete(self, key):
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with self.lock:
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if key in self.data:
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self.data.pop(key)
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@ -0,0 +1,2 @@
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from .file_cache import FileCache # noqa
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from .redis_cache import RedisCache # noqa
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@ -0,0 +1,146 @@
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import hashlib
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import os
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from textwrap import dedent
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from ..cache import BaseCache
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from ..controller import CacheController
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try:
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FileNotFoundError
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except NameError:
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# py2.X
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FileNotFoundError = (IOError, OSError)
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def _secure_open_write(filename, fmode):
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# We only want to write to this file, so open it in write only mode
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flags = os.O_WRONLY
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# os.O_CREAT | os.O_EXCL will fail if the file already exists, so we only
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# will open *new* files.
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# We specify this because we want to ensure that the mode we pass is the
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# mode of the file.
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flags |= os.O_CREAT | os.O_EXCL
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# Do not follow symlinks to prevent someone from making a symlink that
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# we follow and insecurely open a cache file.
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if hasattr(os, "O_NOFOLLOW"):
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flags |= os.O_NOFOLLOW
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# On Windows we'll mark this file as binary
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if hasattr(os, "O_BINARY"):
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flags |= os.O_BINARY
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# Before we open our file, we want to delete any existing file that is
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# there
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try:
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os.remove(filename)
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except (IOError, OSError):
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# The file must not exist already, so we can just skip ahead to opening
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pass
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# Open our file, the use of os.O_CREAT | os.O_EXCL will ensure that if a
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# race condition happens between the os.remove and this line, that an
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# error will be raised. Because we utilize a lockfile this should only
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# happen if someone is attempting to attack us.
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fd = os.open(filename, flags, fmode)
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try:
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return os.fdopen(fd, "wb")
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except:
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# An error occurred wrapping our FD in a file object
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os.close(fd)
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raise
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class FileCache(BaseCache):
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def __init__(
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self,
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directory,
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forever=False,
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filemode=0o0600,
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dirmode=0o0700,
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use_dir_lock=None,
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lock_class=None,
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):
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if use_dir_lock is not None and lock_class is not None:
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raise ValueError("Cannot use use_dir_lock and lock_class together")
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try:
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from lockfile import LockFile
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from lockfile.mkdirlockfile import MkdirLockFile
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except ImportError:
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notice = dedent(
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"""
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NOTE: In order to use the FileCache you must have
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lockfile installed. You can install it via pip:
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pip install lockfile
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"""
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)
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raise ImportError(notice)
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else:
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if use_dir_lock:
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lock_class = MkdirLockFile
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elif lock_class is None:
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lock_class = LockFile
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self.directory = directory
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self.forever = forever
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self.filemode = filemode
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self.dirmode = dirmode
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self.lock_class = lock_class
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@staticmethod
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def encode(x):
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return hashlib.sha224(x.encode()).hexdigest()
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def _fn(self, name):
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# NOTE: This method should not change as some may depend on it.
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# See: https://github.com/ionrock/cachecontrol/issues/63
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hashed = self.encode(name)
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parts = list(hashed[:5]) + [hashed]
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return os.path.join(self.directory, *parts)
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def get(self, key):
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name = self._fn(key)
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try:
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with open(name, "rb") as fh:
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return fh.read()
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except FileNotFoundError:
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return None
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def set(self, key, value):
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name = self._fn(key)
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# Make sure the directory exists
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try:
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os.makedirs(os.path.dirname(name), self.dirmode)
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except (IOError, OSError):
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pass
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with self.lock_class(name) as lock:
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# Write our actual file
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with _secure_open_write(lock.path, self.filemode) as fh:
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fh.write(value)
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def delete(self, key):
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name = self._fn(key)
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if not self.forever:
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try:
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os.remove(name)
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except FileNotFoundError:
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pass
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def url_to_file_path(url, filecache):
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"""Return the file cache path based on the URL.
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This does not ensure the file exists!
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"""
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key = CacheController.cache_url(url)
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return filecache._fn(key)
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@ -0,0 +1,33 @@
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from __future__ import division
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from datetime import datetime
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from pip._vendor.cachecontrol.cache import BaseCache
|
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|
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class RedisCache(BaseCache):
|
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def __init__(self, conn):
|
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self.conn = conn
|
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|
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def get(self, key):
|
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return self.conn.get(key)
|
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def set(self, key, value, expires=None):
|
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if not expires:
|
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self.conn.set(key, value)
|
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else:
|
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expires = expires - datetime.utcnow()
|
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self.conn.setex(key, int(expires.total_seconds()), value)
|
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|
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def delete(self, key):
|
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self.conn.delete(key)
|
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|
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def clear(self):
|
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"""Helper for clearing all the keys in a database. Use with
|
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caution!"""
|
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for key in self.conn.keys():
|
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self.conn.delete(key)
|
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|
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def close(self):
|
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"""Redis uses connection pooling, no need to close the connection."""
|
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pass
|
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@ -0,0 +1,29 @@
|
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try:
|
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from urllib.parse import urljoin
|
||||
except ImportError:
|
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from urlparse import urljoin
|
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|
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|
||||
try:
|
||||
import cPickle as pickle
|
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except ImportError:
|
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import pickle
|
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|
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|
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# Handle the case where the requests module has been patched to not have
|
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# urllib3 bundled as part of its source.
|
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try:
|
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from pip._vendor.requests.packages.urllib3.response import HTTPResponse
|
||||
except ImportError:
|
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from pip._vendor.urllib3.response import HTTPResponse
|
||||
|
||||
try:
|
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from pip._vendor.requests.packages.urllib3.util import is_fp_closed
|
||||
except ImportError:
|
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from pip._vendor.urllib3.util import is_fp_closed
|
||||
|
||||
# Replicate some six behaviour
|
||||
try:
|
||||
text_type = unicode
|
||||
except NameError:
|
||||
text_type = str
|
||||
@ -0,0 +1,376 @@
|
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"""
|
||||
The httplib2 algorithms ported for use with requests.
|
||||
"""
|
||||
import logging
|
||||
import re
|
||||
import calendar
|
||||
import time
|
||||
from email.utils import parsedate_tz
|
||||
|
||||
from pip._vendor.requests.structures import CaseInsensitiveDict
|
||||
|
||||
from .cache import DictCache
|
||||
from .serialize import Serializer
|
||||
|
||||
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
URI = re.compile(r"^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?")
|
||||
|
||||
|
||||
def parse_uri(uri):
|
||||
"""Parses a URI using the regex given in Appendix B of RFC 3986.
|
||||
|
||||
(scheme, authority, path, query, fragment) = parse_uri(uri)
|
||||
"""
|
||||
groups = URI.match(uri).groups()
|
||||
return (groups[1], groups[3], groups[4], groups[6], groups[8])
|
||||
|
||||
|
||||
class CacheController(object):
|
||||
"""An interface to see if request should cached or not.
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self, cache=None, cache_etags=True, serializer=None, status_codes=None
|
||||
):
|
||||
self.cache = DictCache() if cache is None else cache
|
||||
self.cache_etags = cache_etags
|
||||
self.serializer = serializer or Serializer()
|
||||
self.cacheable_status_codes = status_codes or (200, 203, 300, 301)
|
||||
|
||||
@classmethod
|
||||
def _urlnorm(cls, uri):
|
||||
"""Normalize the URL to create a safe key for the cache"""
|
||||
(scheme, authority, path, query, fragment) = parse_uri(uri)
|
||||
if not scheme or not authority:
|
||||
raise Exception("Only absolute URIs are allowed. uri = %s" % uri)
|
||||
|
||||
scheme = scheme.lower()
|
||||
authority = authority.lower()
|
||||
|
||||
if not path:
|
||||
path = "/"
|
||||
|
||||
# Could do syntax based normalization of the URI before
|
||||
# computing the digest. See Section 6.2.2 of Std 66.
|
||||
request_uri = query and "?".join([path, query]) or path
|
||||
defrag_uri = scheme + "://" + authority + request_uri
|
||||
|
||||
return defrag_uri
|
||||
|
||||
@classmethod
|
||||
def cache_url(cls, uri):
|
||||
return cls._urlnorm(uri)
|
||||
|
||||
def parse_cache_control(self, headers):
|
||||
known_directives = {
|
||||
# https://tools.ietf.org/html/rfc7234#section-5.2
|
||||
"max-age": (int, True),
|
||||
"max-stale": (int, False),
|
||||
"min-fresh": (int, True),
|
||||
"no-cache": (None, False),
|
||||
"no-store": (None, False),
|
||||
"no-transform": (None, False),
|
||||
"only-if-cached": (None, False),
|
||||
"must-revalidate": (None, False),
|
||||
"public": (None, False),
|
||||
"private": (None, False),
|
||||
"proxy-revalidate": (None, False),
|
||||
"s-maxage": (int, True),
|
||||
}
|
||||
|
||||
cc_headers = headers.get("cache-control", headers.get("Cache-Control", ""))
|
||||
|
||||
retval = {}
|
||||
|
||||
for cc_directive in cc_headers.split(","):
|
||||
if not cc_directive.strip():
|
||||
continue
|
||||
|
||||
parts = cc_directive.split("=", 1)
|
||||
directive = parts[0].strip()
|
||||
|
||||
try:
|
||||
typ, required = known_directives[directive]
|
||||
except KeyError:
|
||||
logger.debug("Ignoring unknown cache-control directive: %s", directive)
|
||||
continue
|
||||
|
||||
if not typ or not required:
|
||||
retval[directive] = None
|
||||
if typ:
|
||||
try:
|
||||
retval[directive] = typ(parts[1].strip())
|
||||
except IndexError:
|
||||
if required:
|
||||
logger.debug(
|
||||
"Missing value for cache-control " "directive: %s",
|
||||
directive,
|
||||
)
|
||||
except ValueError:
|
||||
logger.debug(
|
||||
"Invalid value for cache-control directive " "%s, must be %s",
|
||||
directive,
|
||||
typ.__name__,
|
||||
)
|
||||
|
||||
return retval
|
||||
|
||||
def cached_request(self, request):
|
||||
"""
|
||||
Return a cached response if it exists in the cache, otherwise
|
||||
return False.
|
||||
"""
|
||||
cache_url = self.cache_url(request.url)
|
||||
logger.debug('Looking up "%s" in the cache', cache_url)
|
||||
cc = self.parse_cache_control(request.headers)
|
||||
|
||||
# Bail out if the request insists on fresh data
|
||||
if "no-cache" in cc:
|
||||
logger.debug('Request header has "no-cache", cache bypassed')
|
||||
return False
|
||||
|
||||
if "max-age" in cc and cc["max-age"] == 0:
|
||||
logger.debug('Request header has "max_age" as 0, cache bypassed')
|
||||
return False
|
||||
|
||||
# Request allows serving from the cache, let's see if we find something
|
||||
cache_data = self.cache.get(cache_url)
|
||||
if cache_data is None:
|
||||
logger.debug("No cache entry available")
|
||||
return False
|
||||
|
||||
# Check whether it can be deserialized
|
||||
resp = self.serializer.loads(request, cache_data)
|
||||
if not resp:
|
||||
logger.warning("Cache entry deserialization failed, entry ignored")
|
||||
return False
|
||||
|
||||
# If we have a cached 301, return it immediately. We don't
|
||||
# need to test our response for other headers b/c it is
|
||||
# intrinsically "cacheable" as it is Permanent.
|
||||
# See:
|
||||
# https://tools.ietf.org/html/rfc7231#section-6.4.2
|
||||
#
|
||||
# Client can try to refresh the value by repeating the request
|
||||
# with cache busting headers as usual (ie no-cache).
|
||||
if resp.status == 301:
|
||||
msg = (
|
||||
'Returning cached "301 Moved Permanently" response '
|
||||
"(ignoring date and etag information)"
|
||||
)
|
||||
logger.debug(msg)
|
||||
return resp
|
||||
|
||||
headers = CaseInsensitiveDict(resp.headers)
|
||||
if not headers or "date" not in headers:
|
||||
if "etag" not in headers:
|
||||
# Without date or etag, the cached response can never be used
|
||||
# and should be deleted.
|
||||
logger.debug("Purging cached response: no date or etag")
|
||||
self.cache.delete(cache_url)
|
||||
logger.debug("Ignoring cached response: no date")
|
||||
return False
|
||||
|
||||
now = time.time()
|
||||
date = calendar.timegm(parsedate_tz(headers["date"]))
|
||||
current_age = max(0, now - date)
|
||||
logger.debug("Current age based on date: %i", current_age)
|
||||
|
||||
# TODO: There is an assumption that the result will be a
|
||||
# urllib3 response object. This may not be best since we
|
||||
# could probably avoid instantiating or constructing the
|
||||
# response until we know we need it.
|
||||
resp_cc = self.parse_cache_control(headers)
|
||||
|
||||
# determine freshness
|
||||
freshness_lifetime = 0
|
||||
|
||||
# Check the max-age pragma in the cache control header
|
||||
if "max-age" in resp_cc:
|
||||
freshness_lifetime = resp_cc["max-age"]
|
||||
logger.debug("Freshness lifetime from max-age: %i", freshness_lifetime)
|
||||
|
||||
# If there isn't a max-age, check for an expires header
|
||||
elif "expires" in headers:
|
||||
expires = parsedate_tz(headers["expires"])
|
||||
if expires is not None:
|
||||
expire_time = calendar.timegm(expires) - date
|
||||
freshness_lifetime = max(0, expire_time)
|
||||
logger.debug("Freshness lifetime from expires: %i", freshness_lifetime)
|
||||
|
||||
# Determine if we are setting freshness limit in the
|
||||
# request. Note, this overrides what was in the response.
|
||||
if "max-age" in cc:
|
||||
freshness_lifetime = cc["max-age"]
|
||||
logger.debug(
|
||||
"Freshness lifetime from request max-age: %i", freshness_lifetime
|
||||
)
|
||||
|
||||
if "min-fresh" in cc:
|
||||
min_fresh = cc["min-fresh"]
|
||||
# adjust our current age by our min fresh
|
||||
current_age += min_fresh
|
||||
logger.debug("Adjusted current age from min-fresh: %i", current_age)
|
||||
|
||||
# Return entry if it is fresh enough
|
||||
if freshness_lifetime > current_age:
|
||||
logger.debug('The response is "fresh", returning cached response')
|
||||
logger.debug("%i > %i", freshness_lifetime, current_age)
|
||||
return resp
|
||||
|
||||
# we're not fresh. If we don't have an Etag, clear it out
|
||||
if "etag" not in headers:
|
||||
logger.debug('The cached response is "stale" with no etag, purging')
|
||||
self.cache.delete(cache_url)
|
||||
|
||||
# return the original handler
|
||||
return False
|
||||
|
||||
def conditional_headers(self, request):
|
||||
cache_url = self.cache_url(request.url)
|
||||
resp = self.serializer.loads(request, self.cache.get(cache_url))
|
||||
new_headers = {}
|
||||
|
||||
if resp:
|
||||
headers = CaseInsensitiveDict(resp.headers)
|
||||
|
||||
if "etag" in headers:
|
||||
new_headers["If-None-Match"] = headers["ETag"]
|
||||
|
||||
if "last-modified" in headers:
|
||||
new_headers["If-Modified-Since"] = headers["Last-Modified"]
|
||||
|
||||
return new_headers
|
||||
|
||||
def cache_response(self, request, response, body=None, status_codes=None):
|
||||
"""
|
||||
Algorithm for caching requests.
|
||||
|
||||
This assumes a requests Response object.
|
||||
"""
|
||||
# From httplib2: Don't cache 206's since we aren't going to
|
||||
# handle byte range requests
|
||||
cacheable_status_codes = status_codes or self.cacheable_status_codes
|
||||
if response.status not in cacheable_status_codes:
|
||||
logger.debug(
|
||||
"Status code %s not in %s", response.status, cacheable_status_codes
|
||||
)
|
||||
return
|
||||
|
||||
response_headers = CaseInsensitiveDict(response.headers)
|
||||
|
||||
# If we've been given a body, our response has a Content-Length, that
|
||||
# Content-Length is valid then we can check to see if the body we've
|
||||
# been given matches the expected size, and if it doesn't we'll just
|
||||
# skip trying to cache it.
|
||||
if (
|
||||
body is not None
|
||||
and "content-length" in response_headers
|
||||
and response_headers["content-length"].isdigit()
|
||||
and int(response_headers["content-length"]) != len(body)
|
||||
):
|
||||
return
|
||||
|
||||
cc_req = self.parse_cache_control(request.headers)
|
||||
cc = self.parse_cache_control(response_headers)
|
||||
|
||||
cache_url = self.cache_url(request.url)
|
||||
logger.debug('Updating cache with response from "%s"', cache_url)
|
||||
|
||||
# Delete it from the cache if we happen to have it stored there
|
||||
no_store = False
|
||||
if "no-store" in cc:
|
||||
no_store = True
|
||||
logger.debug('Response header has "no-store"')
|
||||
if "no-store" in cc_req:
|
||||
no_store = True
|
||||
logger.debug('Request header has "no-store"')
|
||||
if no_store and self.cache.get(cache_url):
|
||||
logger.debug('Purging existing cache entry to honor "no-store"')
|
||||
self.cache.delete(cache_url)
|
||||
if no_store:
|
||||
return
|
||||
|
||||
# https://tools.ietf.org/html/rfc7234#section-4.1:
|
||||
# A Vary header field-value of "*" always fails to match.
|
||||
# Storing such a response leads to a deserialization warning
|
||||
# during cache lookup and is not allowed to ever be served,
|
||||
# so storing it can be avoided.
|
||||
if "*" in response_headers.get("vary", ""):
|
||||
logger.debug('Response header has "Vary: *"')
|
||||
return
|
||||
|
||||
# If we've been given an etag, then keep the response
|
||||
if self.cache_etags and "etag" in response_headers:
|
||||
logger.debug("Caching due to etag")
|
||||
self.cache.set(
|
||||
cache_url, self.serializer.dumps(request, response, body=body)
|
||||
)
|
||||
|
||||
# Add to the cache any 301s. We do this before looking that
|
||||
# the Date headers.
|
||||
elif response.status == 301:
|
||||
logger.debug("Caching permanant redirect")
|
||||
self.cache.set(cache_url, self.serializer.dumps(request, response))
|
||||
|
||||
# Add to the cache if the response headers demand it. If there
|
||||
# is no date header then we can't do anything about expiring
|
||||
# the cache.
|
||||
elif "date" in response_headers:
|
||||
# cache when there is a max-age > 0
|
||||
if "max-age" in cc and cc["max-age"] > 0:
|
||||
logger.debug("Caching b/c date exists and max-age > 0")
|
||||
self.cache.set(
|
||||
cache_url, self.serializer.dumps(request, response, body=body)
|
||||
)
|
||||
|
||||
# If the request can expire, it means we should cache it
|
||||
# in the meantime.
|
||||
elif "expires" in response_headers:
|
||||
if response_headers["expires"]:
|
||||
logger.debug("Caching b/c of expires header")
|
||||
self.cache.set(
|
||||
cache_url, self.serializer.dumps(request, response, body=body)
|
||||
)
|
||||
|
||||
def update_cached_response(self, request, response):
|
||||
"""On a 304 we will get a new set of headers that we want to
|
||||
update our cached value with, assuming we have one.
|
||||
|
||||
This should only ever be called when we've sent an ETag and
|
||||
gotten a 304 as the response.
|
||||
"""
|
||||
cache_url = self.cache_url(request.url)
|
||||
|
||||
cached_response = self.serializer.loads(request, self.cache.get(cache_url))
|
||||
|
||||
if not cached_response:
|
||||
# we didn't have a cached response
|
||||
return response
|
||||
|
||||
# Lets update our headers with the headers from the new request:
|
||||
# http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-26#section-4.1
|
||||
#
|
||||
# The server isn't supposed to send headers that would make
|
||||
# the cached body invalid. But... just in case, we'll be sure
|
||||
# to strip out ones we know that might be problmatic due to
|
||||
# typical assumptions.
|
||||
excluded_headers = ["content-length"]
|
||||
|
||||
cached_response.headers.update(
|
||||
dict(
|
||||
(k, v)
|
||||
for k, v in response.headers.items()
|
||||
if k.lower() not in excluded_headers
|
||||
)
|
||||
)
|
||||
|
||||
# we want a 200 b/c we have content via the cache
|
||||
cached_response.status = 200
|
||||
|
||||
# update our cache
|
||||
self.cache.set(cache_url, self.serializer.dumps(request, cached_response))
|
||||
|
||||
return cached_response
|
||||
@ -0,0 +1,80 @@
|
||||
from io import BytesIO
|
||||
|
||||
|
||||
class CallbackFileWrapper(object):
|
||||
"""
|
||||
Small wrapper around a fp object which will tee everything read into a
|
||||
buffer, and when that file is closed it will execute a callback with the
|
||||
contents of that buffer.
|
||||
|
||||
All attributes are proxied to the underlying file object.
|
||||
|
||||
This class uses members with a double underscore (__) leading prefix so as
|
||||
not to accidentally shadow an attribute.
|
||||
"""
|
||||
|
||||
def __init__(self, fp, callback):
|
||||
self.__buf = BytesIO()
|
||||
self.__fp = fp
|
||||
self.__callback = callback
|
||||
|
||||
def __getattr__(self, name):
|
||||
# The vaguaries of garbage collection means that self.__fp is
|
||||
# not always set. By using __getattribute__ and the private
|
||||
# name[0] allows looking up the attribute value and raising an
|
||||
# AttributeError when it doesn't exist. This stop thigns from
|
||||
# infinitely recursing calls to getattr in the case where
|
||||
# self.__fp hasn't been set.
|
||||
#
|
||||
# [0] https://docs.python.org/2/reference/expressions.html#atom-identifiers
|
||||
fp = self.__getattribute__("_CallbackFileWrapper__fp")
|
||||
return getattr(fp, name)
|
||||
|
||||
def __is_fp_closed(self):
|
||||
try:
|
||||
return self.__fp.fp is None
|
||||
|
||||
except AttributeError:
|
||||
pass
|
||||
|
||||
try:
|
||||
return self.__fp.closed
|
||||
|
||||
except AttributeError:
|
||||
pass
|
||||
|
||||
# We just don't cache it then.
|
||||
# TODO: Add some logging here...
|
||||
return False
|
||||
|
||||
def _close(self):
|
||||
if self.__callback:
|
||||
self.__callback(self.__buf.getvalue())
|
||||
|
||||
# We assign this to None here, because otherwise we can get into
|
||||
# really tricky problems where the CPython interpreter dead locks
|
||||
# because the callback is holding a reference to something which
|
||||
# has a __del__ method. Setting this to None breaks the cycle
|
||||
# and allows the garbage collector to do it's thing normally.
|
||||
self.__callback = None
|
||||
|
||||
def read(self, amt=None):
|
||||
data = self.__fp.read(amt)
|
||||
self.__buf.write(data)
|
||||
if self.__is_fp_closed():
|
||||
self._close()
|
||||
|
||||
return data
|
||||
|
||||
def _safe_read(self, amt):
|
||||
data = self.__fp._safe_read(amt)
|
||||
if amt == 2 and data == b"\r\n":
|
||||
# urllib executes this read to toss the CRLF at the end
|
||||
# of the chunk.
|
||||
return data
|
||||
|
||||
self.__buf.write(data)
|
||||
if self.__is_fp_closed():
|
||||
self._close()
|
||||
|
||||
return data
|
||||
@ -0,0 +1,135 @@
|
||||
import calendar
|
||||
import time
|
||||
|
||||
from email.utils import formatdate, parsedate, parsedate_tz
|
||||
|
||||
from datetime import datetime, timedelta
|
||||
|
||||
TIME_FMT = "%a, %d %b %Y %H:%M:%S GMT"
|
||||
|
||||
|
||||
def expire_after(delta, date=None):
|
||||
date = date or datetime.utcnow()
|
||||
return date + delta
|
||||
|
||||
|
||||
def datetime_to_header(dt):
|
||||
return formatdate(calendar.timegm(dt.timetuple()))
|
||||
|
||||
|
||||
class BaseHeuristic(object):
|
||||
|
||||
def warning(self, response):
|
||||
"""
|
||||
Return a valid 1xx warning header value describing the cache
|
||||
adjustments.
|
||||
|
||||
The response is provided too allow warnings like 113
|
||||
http://tools.ietf.org/html/rfc7234#section-5.5.4 where we need
|
||||
to explicitly say response is over 24 hours old.
|
||||
"""
|
||||
return '110 - "Response is Stale"'
|
||||
|
||||
def update_headers(self, response):
|
||||
"""Update the response headers with any new headers.
|
||||
|
||||
NOTE: This SHOULD always include some Warning header to
|
||||
signify that the response was cached by the client, not
|
||||
by way of the provided headers.
|
||||
"""
|
||||
return {}
|
||||
|
||||
def apply(self, response):
|
||||
updated_headers = self.update_headers(response)
|
||||
|
||||
if updated_headers:
|
||||
response.headers.update(updated_headers)
|
||||
warning_header_value = self.warning(response)
|
||||
if warning_header_value is not None:
|
||||
response.headers.update({"Warning": warning_header_value})
|
||||
|
||||
return response
|
||||
|
||||
|
||||
class OneDayCache(BaseHeuristic):
|
||||
"""
|
||||
Cache the response by providing an expires 1 day in the
|
||||
future.
|
||||
"""
|
||||
|
||||
def update_headers(self, response):
|
||||
headers = {}
|
||||
|
||||
if "expires" not in response.headers:
|
||||
date = parsedate(response.headers["date"])
|
||||
expires = expire_after(timedelta(days=1), date=datetime(*date[:6]))
|
||||
headers["expires"] = datetime_to_header(expires)
|
||||
headers["cache-control"] = "public"
|
||||
return headers
|
||||
|
||||
|
||||
class ExpiresAfter(BaseHeuristic):
|
||||
"""
|
||||
Cache **all** requests for a defined time period.
|
||||
"""
|
||||
|
||||
def __init__(self, **kw):
|
||||
self.delta = timedelta(**kw)
|
||||
|
||||
def update_headers(self, response):
|
||||
expires = expire_after(self.delta)
|
||||
return {"expires": datetime_to_header(expires), "cache-control": "public"}
|
||||
|
||||
def warning(self, response):
|
||||
tmpl = "110 - Automatically cached for %s. Response might be stale"
|
||||
return tmpl % self.delta
|
||||
|
||||
|
||||
class LastModified(BaseHeuristic):
|
||||
"""
|
||||
If there is no Expires header already, fall back on Last-Modified
|
||||
using the heuristic from
|
||||
http://tools.ietf.org/html/rfc7234#section-4.2.2
|
||||
to calculate a reasonable value.
|
||||
|
||||
Firefox also does something like this per
|
||||
https://developer.mozilla.org/en-US/docs/Web/HTTP/Caching_FAQ
|
||||
http://lxr.mozilla.org/mozilla-release/source/netwerk/protocol/http/nsHttpResponseHead.cpp#397
|
||||
Unlike mozilla we limit this to 24-hr.
|
||||
"""
|
||||
cacheable_by_default_statuses = {
|
||||
200, 203, 204, 206, 300, 301, 404, 405, 410, 414, 501
|
||||
}
|
||||
|
||||
def update_headers(self, resp):
|
||||
headers = resp.headers
|
||||
|
||||
if "expires" in headers:
|
||||
return {}
|
||||
|
||||
if "cache-control" in headers and headers["cache-control"] != "public":
|
||||
return {}
|
||||
|
||||
if resp.status not in self.cacheable_by_default_statuses:
|
||||
return {}
|
||||
|
||||
if "date" not in headers or "last-modified" not in headers:
|
||||
return {}
|
||||
|
||||
date = calendar.timegm(parsedate_tz(headers["date"]))
|
||||
last_modified = parsedate(headers["last-modified"])
|
||||
if date is None or last_modified is None:
|
||||
return {}
|
||||
|
||||
now = time.time()
|
||||
current_age = max(0, now - date)
|
||||
delta = date - calendar.timegm(last_modified)
|
||||
freshness_lifetime = max(0, min(delta / 10, 24 * 3600))
|
||||
if freshness_lifetime <= current_age:
|
||||
return {}
|
||||
|
||||
expires = date + freshness_lifetime
|
||||
return {"expires": time.strftime(TIME_FMT, time.gmtime(expires))}
|
||||
|
||||
def warning(self, resp):
|
||||
return None
|
||||
@ -0,0 +1,188 @@
|
||||
import base64
|
||||
import io
|
||||
import json
|
||||
import zlib
|
||||
|
||||
from pip._vendor import msgpack
|
||||
from pip._vendor.requests.structures import CaseInsensitiveDict
|
||||
|
||||
from .compat import HTTPResponse, pickle, text_type
|
||||
|
||||
|
||||
def _b64_decode_bytes(b):
|
||||
return base64.b64decode(b.encode("ascii"))
|
||||
|
||||
|
||||
def _b64_decode_str(s):
|
||||
return _b64_decode_bytes(s).decode("utf8")
|
||||
|
||||
|
||||
class Serializer(object):
|
||||
|
||||
def dumps(self, request, response, body=None):
|
||||
response_headers = CaseInsensitiveDict(response.headers)
|
||||
|
||||
if body is None:
|
||||
body = response.read(decode_content=False)
|
||||
|
||||
# NOTE: 99% sure this is dead code. I'm only leaving it
|
||||
# here b/c I don't have a test yet to prove
|
||||
# it. Basically, before using
|
||||
# `cachecontrol.filewrapper.CallbackFileWrapper`,
|
||||
# this made an effort to reset the file handle. The
|
||||
# `CallbackFileWrapper` short circuits this code by
|
||||
# setting the body as the content is consumed, the
|
||||
# result being a `body` argument is *always* passed
|
||||
# into cache_response, and in turn,
|
||||
# `Serializer.dump`.
|
||||
response._fp = io.BytesIO(body)
|
||||
|
||||
# NOTE: This is all a bit weird, but it's really important that on
|
||||
# Python 2.x these objects are unicode and not str, even when
|
||||
# they contain only ascii. The problem here is that msgpack
|
||||
# understands the difference between unicode and bytes and we
|
||||
# have it set to differentiate between them, however Python 2
|
||||
# doesn't know the difference. Forcing these to unicode will be
|
||||
# enough to have msgpack know the difference.
|
||||
data = {
|
||||
u"response": {
|
||||
u"body": body,
|
||||
u"headers": dict(
|
||||
(text_type(k), text_type(v)) for k, v in response.headers.items()
|
||||
),
|
||||
u"status": response.status,
|
||||
u"version": response.version,
|
||||
u"reason": text_type(response.reason),
|
||||
u"strict": response.strict,
|
||||
u"decode_content": response.decode_content,
|
||||
}
|
||||
}
|
||||
|
||||
# Construct our vary headers
|
||||
data[u"vary"] = {}
|
||||
if u"vary" in response_headers:
|
||||
varied_headers = response_headers[u"vary"].split(",")
|
||||
for header in varied_headers:
|
||||
header = text_type(header).strip()
|
||||
header_value = request.headers.get(header, None)
|
||||
if header_value is not None:
|
||||
header_value = text_type(header_value)
|
||||
data[u"vary"][header] = header_value
|
||||
|
||||
return b",".join([b"cc=4", msgpack.dumps(data, use_bin_type=True)])
|
||||
|
||||
def loads(self, request, data):
|
||||
# Short circuit if we've been given an empty set of data
|
||||
if not data:
|
||||
return
|
||||
|
||||
# Determine what version of the serializer the data was serialized
|
||||
# with
|
||||
try:
|
||||
ver, data = data.split(b",", 1)
|
||||
except ValueError:
|
||||
ver = b"cc=0"
|
||||
|
||||
# Make sure that our "ver" is actually a version and isn't a false
|
||||
# positive from a , being in the data stream.
|
||||
if ver[:3] != b"cc=":
|
||||
data = ver + data
|
||||
ver = b"cc=0"
|
||||
|
||||
# Get the version number out of the cc=N
|
||||
ver = ver.split(b"=", 1)[-1].decode("ascii")
|
||||
|
||||
# Dispatch to the actual load method for the given version
|
||||
try:
|
||||
return getattr(self, "_loads_v{}".format(ver))(request, data)
|
||||
|
||||
except AttributeError:
|
||||
# This is a version we don't have a loads function for, so we'll
|
||||
# just treat it as a miss and return None
|
||||
return
|
||||
|
||||
def prepare_response(self, request, cached):
|
||||
"""Verify our vary headers match and construct a real urllib3
|
||||
HTTPResponse object.
|
||||
"""
|
||||
# Special case the '*' Vary value as it means we cannot actually
|
||||
# determine if the cached response is suitable for this request.
|
||||
# This case is also handled in the controller code when creating
|
||||
# a cache entry, but is left here for backwards compatibility.
|
||||
if "*" in cached.get("vary", {}):
|
||||
return
|
||||
|
||||
# Ensure that the Vary headers for the cached response match our
|
||||
# request
|
||||
for header, value in cached.get("vary", {}).items():
|
||||
if request.headers.get(header, None) != value:
|
||||
return
|
||||
|
||||
body_raw = cached["response"].pop("body")
|
||||
|
||||
headers = CaseInsensitiveDict(data=cached["response"]["headers"])
|
||||
if headers.get("transfer-encoding", "") == "chunked":
|
||||
headers.pop("transfer-encoding")
|
||||
|
||||
cached["response"]["headers"] = headers
|
||||
|
||||
try:
|
||||
body = io.BytesIO(body_raw)
|
||||
except TypeError:
|
||||
# This can happen if cachecontrol serialized to v1 format (pickle)
|
||||
# using Python 2. A Python 2 str(byte string) will be unpickled as
|
||||
# a Python 3 str (unicode string), which will cause the above to
|
||||
# fail with:
|
||||
#
|
||||
# TypeError: 'str' does not support the buffer interface
|
||||
body = io.BytesIO(body_raw.encode("utf8"))
|
||||
|
||||
return HTTPResponse(body=body, preload_content=False, **cached["response"])
|
||||
|
||||
def _loads_v0(self, request, data):
|
||||
# The original legacy cache data. This doesn't contain enough
|
||||
# information to construct everything we need, so we'll treat this as
|
||||
# a miss.
|
||||
return
|
||||
|
||||
def _loads_v1(self, request, data):
|
||||
try:
|
||||
cached = pickle.loads(data)
|
||||
except ValueError:
|
||||
return
|
||||
|
||||
return self.prepare_response(request, cached)
|
||||
|
||||
def _loads_v2(self, request, data):
|
||||
try:
|
||||
cached = json.loads(zlib.decompress(data).decode("utf8"))
|
||||
except (ValueError, zlib.error):
|
||||
return
|
||||
|
||||
# We need to decode the items that we've base64 encoded
|
||||
cached["response"]["body"] = _b64_decode_bytes(cached["response"]["body"])
|
||||
cached["response"]["headers"] = dict(
|
||||
(_b64_decode_str(k), _b64_decode_str(v))
|
||||
for k, v in cached["response"]["headers"].items()
|
||||
)
|
||||
cached["response"]["reason"] = _b64_decode_str(cached["response"]["reason"])
|
||||
cached["vary"] = dict(
|
||||
(_b64_decode_str(k), _b64_decode_str(v) if v is not None else v)
|
||||
for k, v in cached["vary"].items()
|
||||
)
|
||||
|
||||
return self.prepare_response(request, cached)
|
||||
|
||||
def _loads_v3(self, request, data):
|
||||
# Due to Python 2 encoding issues, it's impossible to know for sure
|
||||
# exactly how to load v3 entries, thus we'll treat these as a miss so
|
||||
# that they get rewritten out as v4 entries.
|
||||
return
|
||||
|
||||
def _loads_v4(self, request, data):
|
||||
try:
|
||||
cached = msgpack.loads(data, raw=False)
|
||||
except ValueError:
|
||||
return
|
||||
|
||||
return self.prepare_response(request, cached)
|
||||
@ -0,0 +1,29 @@
|
||||
from .adapter import CacheControlAdapter
|
||||
from .cache import DictCache
|
||||
|
||||
|
||||
def CacheControl(
|
||||
sess,
|
||||
cache=None,
|
||||
cache_etags=True,
|
||||
serializer=None,
|
||||
heuristic=None,
|
||||
controller_class=None,
|
||||
adapter_class=None,
|
||||
cacheable_methods=None,
|
||||
):
|
||||
|
||||
cache = DictCache() if cache is None else cache
|
||||
adapter_class = adapter_class or CacheControlAdapter
|
||||
adapter = adapter_class(
|
||||
cache,
|
||||
cache_etags=cache_etags,
|
||||
serializer=serializer,
|
||||
heuristic=heuristic,
|
||||
controller_class=controller_class,
|
||||
cacheable_methods=cacheable_methods,
|
||||
)
|
||||
sess.mount("http://", adapter)
|
||||
sess.mount("https://", adapter)
|
||||
|
||||
return sess
|
||||
Reference in New Issue
Block a user