3 ÝPf-ã@sŽddlZddlZddlmZmZmZddlmZmZdZddd„Z dd„Z Gd d „d e ƒZ Gd d „d e ƒZ Gd d„de ƒZGdd„de ƒZdS)éN)Ú formatdateÚ parsedateÚ parsedate_tz)ÚdatetimeÚ timedeltaz%a, %d %b %Y %H:%M:%S GMTcCs|p tjƒ}||S)N)rÚnow)ÚdeltaÚdate©r ú /usr/lib/python3.6/heuristics.pyÚ expire_after s r cCsttj|jƒƒƒS)N)rÚcalendarÚtimegmZ timetuple)Zdtr r r Údatetime_to_headersrc@s$eZdZdd„Zdd„Zdd„ZdS)Ú BaseHeuristiccCsdS)a! Return a valid 1xx warning header value describing the cache adjustments. The response is provided too allow warnings like 113 http://tools.ietf.org/html/rfc7234#section-5.5.4 where we need to explicitly say response is over 24 hours old. z110 - "Response is Stale"r )ÚselfÚresponser r r Úwarnings zBaseHeuristic.warningcCsiS)zïUpdate the response headers with any new headers. NOTE: This SHOULD always include some Warning header to signify that the response was cached by the client, not by way of the provided headers. r )rrr r r Úupdate_headers!szBaseHeuristic.update_headerscCs@|j|ƒ}|r<|jj|ƒ|j|ƒ}|dk r<|jjd|iƒ|S)NÚWarning)rÚheadersÚupdater)rrZupdated_headersZwarning_header_valuer r r Úapply*s   zBaseHeuristic.applyN)Ú__name__Ú __module__Ú __qualname__rrrr r r r rs  rc@seZdZdZdd„ZdS)Ú OneDayCachezM Cache the response by providing an expires 1 day in the future. cCsRi}d|jkrNt|jdƒ}ttddt|dd…Žd}t|ƒ|d<d|d<|S) NÚexpiresr é)Zdaysé)r Úpublicz cache-control)rrr rrr)rrrr rr r r r;s   zOneDayCache.update_headersN)rrrÚ__doc__rr r r r r6src@s(eZdZdZdd„Zdd„Zdd„ZdS) Ú ExpiresAfterz; Cache **all** requests for a defined time period. cKstf|Ž|_dS)N)rr)rÚkwr r r Ú__init__LszExpiresAfter.__init__cCst|jƒ}t|ƒddœS)Nr )rz cache-control)r rr)rrrr r r rOs zExpiresAfter.update_headerscCsd}||jS)Nz:110 - Automatically cached for %s. Response might be stale)r)rrZtmplr r r rVszExpiresAfter.warningN)rrrr!r$rrr r r r r"Gsr"c @s>eZdZdZedddddddd d d d g ƒZd d„Zdd„ZdS)Ú LastModifiedaÁ 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. éÈéËéÌéÎi,i-i”i•išižiõc Csâ|j}d|kriSd|kr*|ddkr*iS|j|jkr:iSd|ksJd|krNiStjt|dƒƒ}t|dƒ}|dks||dkr€iStjƒ}td||ƒ}|tj|ƒ}tdt |dd ƒƒ}||krÄiS||} dtj t tj | ƒƒiS) Nrz cache-controlr r z last-modifiedré éii€Q) rZstatusÚcacheable_by_default_statusesr rrrÚtimeÚmaxÚminZstrftimeÚTIME_FMTZgmtime) rÚresprr Z last_modifiedrZ current_agerZfreshness_lifetimerr r r rks*  zLastModified.update_headerscCsdS)Nr )rr1r r r r‰szLastModified.warningN)rrrr!Úsetr,rrr r r r r%[s  r%)N)r r-Z email.utilsrrrrrr0r rÚobjectrrr"r%r r r r Ús "