Class CacheController

cachecontrol/controller.py:50–511

An interface to see if request should cached or not.

class CacheController:
    """An interface to see if request should cached or not."""

    def __init__(
        self,
        cache: BaseCache | None = None,
        cache_etags: bool = True,
        serializer: Serializer | None = None,
        status_codes: Collection[int] | None = 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, 308)

    @classmethod
    def _urlnorm(cls, uri: str) -> str:
        """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: str) -> str:
        return cls._urlnorm(uri)

    def parse_cache_control(self, headers: Mapping[str, str]) -> dict[str, int | None]:
        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", ""))