Include HTTP 308 as a permanent redirect.

The new status code was introduced with RFC 7538 in April 2015.

This makes it so that "308 Permanent Redirect" status codes are treated the
same as "301 Moved Permanently" statuses.

Author: Flameeyes

cachecontrol/controller.py

@@ -17,6 +17,8 @@
 
 URI = re.compile(r"^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?")
 
+PERMANENT_REDIRECT_STATUSES = (301, 308)
+
 
 def parse_uri(uri):
     """Parses a URI using the regex given in Appendix B of RFC 3986.
@@ -37,7 +39,7 @@ def __init__(
         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)
+        self.cacheable_status_codes = status_codes or (200, 203, 300, 301, 308)
 
     @classmethod
     def _urlnorm(cls, uri):
@@ -147,17 +149,18 @@ def cached_request(self, request):
             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
+        # If we have a cached permanent redirect, 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:
+        if int(resp.status) in PERMANENT_REDIRECT_STATUSES:
             msg = (
-                'Returning cached "301 Moved Permanently" response '
+                'Returning cached permanent redirect response '
                 "(ignoring date and etag information)"
             )
             logger.debug(msg)
@@ -309,9 +312,9 @@ def cache_response(self, request, response, body=None, status_codes=None):
                 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:
+        # Add to the cache any permanent redirects. We do this before looking
+        # that the Date headers.
+        elif int(response.status) in PERMANENT_REDIRECT_STATUSES:
             logger.debug("Caching permanent redirect")
             self.cache.set(cache_url, self.serializer.dumps(request, response))
 

tests/test_cache_control.py

@@ -152,7 +152,7 @@ def req(self, headers):
         return self.c.cached_request(mock_request)
 
     def test_cache_request_no_headers(self):
-        cached_resp = Mock(headers={"ETag": "jfd9094r808", "Content-Length": 100})
+        cached_resp = Mock(headers={"ETag": "jfd9094r808", "Content-Length": 100}, status=200)
         self.c.cache = DictCache({self.url: cached_resp})
         resp = self.req({})
         assert not resp
@@ -179,7 +179,7 @@ def test_cache_request_not_in_cache(self):
 
     def test_cache_request_fresh_max_age(self):
         now = time.strftime(TIME_FMT, time.gmtime())
-        resp = Mock(headers={"cache-control": "max-age=3600", "date": now})
+        resp = Mock(headers={"cache-control": "max-age=3600", "date": now}, status=200)
 
         cache = DictCache({self.url: resp})
         self.c.cache = cache
@@ -189,7 +189,7 @@ def test_cache_request_fresh_max_age(self):
     def test_cache_request_unfresh_max_age(self):
         earlier = time.time() - 3700  # epoch - 1h01m40s
         now = time.strftime(TIME_FMT, time.gmtime(earlier))
-        resp = Mock(headers={"cache-control": "max-age=3600", "date": now})
+        resp = Mock(headers={"cache-control": "max-age=3600", "date": now}, status=200)
         self.c.cache = DictCache({self.url: resp})
         r = self.req({})
         assert not r
@@ -198,7 +198,7 @@ def test_cache_request_fresh_expires(self):
         later = time.time() + 86400  # GMT + 1 day
         expires = time.strftime(TIME_FMT, time.gmtime(later))
         now = time.strftime(TIME_FMT, time.gmtime())
-        resp = Mock(headers={"expires": expires, "date": now})
+        resp = Mock(headers={"expires": expires, "date": now}, status=200)
         cache = DictCache({self.url: resp})
         self.c.cache = cache
         r = self.req({})
@@ -208,7 +208,7 @@ def test_cache_request_unfresh_expires(self):
         sooner = time.time() - 86400  # GMT - 1 day
         expires = time.strftime(TIME_FMT, time.gmtime(sooner))
         now = time.strftime(TIME_FMT, time.gmtime())
-        resp = Mock(headers={"expires": expires, "date": now})
+        resp = Mock(headers={"expires": expires, "date": now}, status=200)
         cache = DictCache({self.url: resp})
         self.c.cache = cache
         r = self.req({})
@@ -217,7 +217,7 @@ def test_cache_request_unfresh_expires(self):
     def test_cached_request_with_bad_max_age_headers_not_returned(self):
         now = time.strftime(TIME_FMT, time.gmtime())
         # Not a valid header; this would be from a misconfigured server
-        resp = Mock(headers={"cache-control": "max-age=xxx", "date": now})
+        resp = Mock(headers={"cache-control": "max-age=xxx", "date": now}, status=200)
 
         self.c.cache = DictCache({self.url: resp})