î ªÍX•:ã@sÝdZddlmZddlZddlZddlZddlZddlmZddl m Z ddl m Z m Z ddlmZmZmZddlmZmZmZmZdd lmZdd lmZejd ƒZejd ƒZd d„Zdd„Z dd„Z!dd„Z"ddd„Z#ddddd„Z$ddd„Z%dd„Z&dd„Z'dd „Z(d!d"„Z)d#d$„Z*d%d&„Z+dd'dd(d)„Z,dddd*d+„Z-d,d-„Z.dS).aß This module contains helper functions for controlling caching. It does so by managing the "Vary" header of responses. It includes functions to patch the header of response objects directly and decorators that change functions to do that header-patching themselves. For information on the Vary header, see: https://tools.ietf.org/html/rfc7231#section-7.1.4 Essentially, the "Vary" HTTP header defines which headers a cache should take into account when building its cache key. Requests with the same path but different header content for headers named in "Vary" need to get different cache keys to prevent delivery of wrong content. An example: i18n middleware would need to distinguish caches by the "Accept-language" header. é)Úunicode_literalsN)Úsettings)Úcaches)Ú HttpResponseÚHttpResponseNotModified)Ú force_bytesÚ force_textÚ iri_to_uri)Ú http_dateÚ parse_etagsÚparse_http_date_safeÚ quote_etag)Úget_current_timezone_name)Ú get_languagez\s*,\s*zdjango.requestc sKdd„‰dd„‰|jdƒr\tj|dƒ}t‡fdd†|Dƒƒ}ni}d|kržd |kržtt|dƒ|d ƒ|d .dictitemcSs2|ddkr|dSd|d|dfSdS)NrTrz%s=%sr)rrrrÚ dictvalue<sz&patch_cache_control..dictvaluez Cache-Controlc3s|]}ˆ|ƒVqdS)Nr)Ú.0Úel)rrrú Dsz&patch_cache_control..zmax-ageÚmax_ageZprivateZpublicÚ_ú-z, c3s|]}ˆ|ƒVqdS)Nr)rr)rrrrVsN) ÚgetÚ cc_delim_rerÚdictÚminÚintÚitemsÚreplaceÚjoin)ÚresponseÚkwargsÚccÚkÚvr)rrrÚpatch_cache_control)s  "$  (r.c Csy|jdƒsdStdd„tj|dƒDƒƒ}d|kruyt|dƒSWquttfk rqYquXndS)zŒ Returns the max-age from the response Cache-Control header as an integer (or ``None`` if it wasn't found or wasn't an integer. z Cache-ControlNcss|]}t|ƒVqdS)N)Ú _to_tuple)rrrrrraszget_max_age..zmax-age)Ú has_headerr#r"rr%Ú ValueErrorÚ TypeError)r)r+rrrÚ get_max_ageZs& r3cCs2|js.ttj|jƒjƒƒ|d.cs(g|]}|jƒˆkr|‘qSr)r)rZ newheader)Úexisting_headersrrú ùs z&patch_vary_headers..z, N)r0r"rÚsetr()r)Ú newheadersÚ vary_headersZadditional_headersr)rXrÚpatch_vary_headersês r]cCsO|jdƒsdStj|dƒ}tdd„|Dƒƒ}|jƒ|kS)zS Checks to see if the response has a given header name in its Vary header. rVFcss|]}|jƒVqdS)N)r)rrWrrrrsz"has_vary_header..)r0r"rrZr)r)Z header_queryr\rXrrrÚhas_vary_headerþs r^cCs†tjstjr2|dt|dtƒƒ7}ntjr‚ttƒddƒ}|d|jddƒj dƒj ddƒ7}n|S)zDIf necessary, adds the current locale or time zone to the cache key.z.%sZ LANGUAGE_CODEÚerrorsÚignoreÚasciiú r) rÚUSE_I18NÚUSE_L10NÚgetattrrZUSE_TZrrÚencodeÚdecoder')r<Ú cache_keyZtz_namerrrÚ_i18n_cache_key_suffix s   2ric Cs¡tjƒ}xB|D]:}|jj|ƒ}|dk r|jt|ƒƒqqWtjtt|jƒƒƒƒ}d|||jƒ|jƒf}t ||ƒS)z>Returns a cache key from the headers given in the header list.Nz-views.decorators.cache.cache_page.%s.%s.%s.%s) r5r6rJr!Úupdaterr Úbuild_absolute_urir8ri) r<rKÚ headerlistÚ key_prefixÚctxrWÚvalueÚurlrhrrrÚ_generate_cache_keys   !rqcCsDtjtt|jƒƒƒƒ}d||jƒf}t||ƒS)z)Returns a cache key for the header cache.z)views.decorators.cache.cache_header.%s.%s)r5r6rr rkr8ri)rmr<rprhrrrÚ_generate_cache_header_key's!rrrFcCsy|dkrtj}nt||ƒ}|dkrCttj}n|j|ƒ}|dk rqt||||ƒSdSdS)af Returns a cache key based on the request URL and query. It can be used in the request phase because it pulls the list of headers to take into account from the global URL registry and uses those to build a cache key to check against. If there is no headerlist stored, the page needs to be rebuilt, so this function returns None. N)rÚCACHE_MIDDLEWARE_KEY_PREFIXrrrÚCACHE_MIDDLEWARE_ALIASr!rq)r<rmrKÚcacherhrlrrrÚ get_cache_key/s    rvc CsA|dkrtj}n|dkr0tj}nt||ƒ}|dkr[ttj}n|jdƒrtjpytj}g}x\t j |dƒD]G}|j ƒj ddƒ}|dkrÌ|rÌq–n|j d|ƒq–W|jƒ|j|||ƒt||j||ƒS|j|g|ƒt||jg|ƒSdS)a´ Learns what headers to take into account for some request URL from the response object. It stores those headers in a global URL registry so that later access to that URL will know what headers to take into account without building the response object itself. The headers are named in the Vary header of the response, but we want to prevent response generation. The list of headers to use for cache key generation is stored in the same cache as the pages themselves. If the cache ages some data out of the cache, this just means that we have to build the response once to get at the Vary header and so at the list of headers to use for the cache key. NrVr rZACCEPT_LANGUAGEZHTTP_)rrsrNrrrrtr0rcrdr"rÚupperr'ÚappendÚsortrZrqrK) r<r)rRrmrurhZis_accept_language_redundantrlrWrrrÚlearn_cache_keyEs(      rzcCsP|jddƒ}t|ƒdkr<|djƒ|dfS|djƒdfS)NrrérT)rrr)rrrrrr/osr/)/Ú__doc__Ú __future__rr5ÚloggingÚrerQZ django.confrZdjango.core.cacherZ django.httprrZdjango.utils.encodingrrr Zdjango.utils.httpr r r r Zdjango.utils.timezonerZdjango.utils.translationrÚcompiler"Ú getLoggerr>r.r3r9rArCrLrSrUr]r^rirqrrrvrzr/rrrrÚs<    " 1    C    *