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-rw-r--r--venv/Lib/site-packages/pip-19.0.3-py3.7.egg/pip/_vendor/cachecontrol/heuristics.py135
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