diff options
Diffstat (limited to 'venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_vendor/cachecontrol/heuristics.py')
-rw-r--r-- | venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_vendor/cachecontrol/heuristics.py | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_vendor/cachecontrol/heuristics.py b/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_vendor/cachecontrol/heuristics.py deleted file mode 100644 index 6c0e979..0000000 --- a/venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_vendor/cachecontrol/heuristics.py +++ /dev/null @@ -1,135 +0,0 @@ -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 |