3 v^)@s~dZddlmZddlmZmZddlmZmZm Z m Z m Z ddl m Z Gddde ZGdd d e ZGd d d eeZd S) a Cache middleware. If enabled, each Django-powered page will be cached based on URL. The canonical way to enable cache middleware is to set ``UpdateCacheMiddleware`` as your first piece of middleware, and ``FetchFromCacheMiddleware`` as the last:: MIDDLEWARE = [ 'django.middleware.cache.UpdateCacheMiddleware', ... 'django.middleware.cache.FetchFromCacheMiddleware' ] This is counter-intuitive, but correct: ``UpdateCacheMiddleware`` needs to run last during the response phase, which processes middleware bottom-up; ``FetchFromCacheMiddleware`` needs to run last during the request phase, which processes middleware top-down. The single-class ``CacheMiddleware`` can be used for some simple sites. However, if any other piece of middleware needs to affect the cache key, you'll need to use the two-part ``UpdateCacheMiddleware`` and ``FetchFromCacheMiddleware``. This'll most often happen when you're using Django's ``LocaleMiddleware``. More details about how the caching works: * Only GET or HEAD-requests with status code 200 are cached. * The number of seconds each page is stored for is set by the "max-age" section of the response's "Cache-Control" header, falling back to the CACHE_MIDDLEWARE_SECONDS setting if the section was not found. * This middleware expects that a HEAD request is answered with the same response headers exactly like the corresponding GET request. * When a hit occurs, a shallow copy of the original response object is returned from process_request. * Pages will be cached based on the contents of the request headers listed in the response's "Vary" header. * This middleware also sets ETag, Last-Modified, Expires and Cache-Control headers on the response object. )settings)DEFAULT_CACHE_ALIAScaches) get_cache_key get_max_agehas_vary_headerlearn_cache_keypatch_response_headers)MiddlewareMixinc@s*eZdZdZd ddZddZddZdS) UpdateCacheMiddlewarea6 Response-phase cache middleware that updates the cache if the response is cacheable. Must be used as part of the two-part update/fetch cache middleware. UpdateCacheMiddleware must be the first piece of middleware in MIDDLEWARE so that it'll get called last during the response phase. NcCs.tj|_tj|_tj|_t|j|_||_ dS)N) rCACHE_MIDDLEWARE_SECONDS cache_timeoutCACHE_MIDDLEWARE_KEY_PREFIX key_prefixCACHE_MIDDLEWARE_ALIAS cache_aliasrcache get_response)selfrr;/usr/lib/python3.6/site-packages/django/middleware/cache.py__init__@s  zUpdateCacheMiddleware.__init__cCst|do|jS)N_cache_update_cache)hasattrr)rrequestresponserrr_should_update_cacheGsz*UpdateCacheMiddleware._should_update_cachecsj||s|S|js |jd kr$|S|j r@|jr@t|dr@|Sd|jdfkrT|St|dkrljn dkrx|St |r|jdkrt ||j j dt |d rt|jr|jfd d nj j||S) zSet the cache, if needed.0Cookieprivatez Cache-ControlNr)rrendercsjj|S)N)rset)r) cache_keyrtimeoutrrjsz8UpdateCacheMiddleware.process_response..)rr)r streaming status_codeCOOKIEScookiesrgetrr r rrrrcallabler!add_post_render_callbackr")rrrr)r$rr%rprocess_responseJs*  z&UpdateCacheMiddleware.process_response)N)__name__ __module__ __qualname____doc__rrr.rrrrr 7s r c@s"eZdZdZdddZddZdS)FetchFromCacheMiddlewarea! Request-phase cache middleware that fetches a page from the cache. Must be used as part of the two-part update/fetch cache middleware. FetchFromCacheMiddleware must be the last piece of middleware in MIDDLEWARE so that it'll get called last during the request phase. NcCs&tj|_tj|_t|j|_||_dS)N)rrrrrrrr)rrrrrrys z!FetchFromCacheMiddleware.__init__cCs|jdkrd|_dSt||jd|jd}|dkr:d|_dS|jj|}|dkrx|jdkrxt||jd|jd}|jj|}|dkrd|_dSd|_|S)zn Check whether the page is already cached and return the cached version if available. GETHEADFN)rT)r4r5)methodrrrrr+)rrr$rrrrprocess_requests    z(FetchFromCacheMiddleware.process_request)N)r/r0r1r2rr7rrrrr3qs r3c@seZdZdZdddZdS)CacheMiddlewarez Cache middleware that provides basic behavior for many simple sites. Also used as the hook point for the cache decorator, which is generated using the decorator-from-middleware utility. NcKs||_y|d}|dkrd}Wntk r8tj}YnX||_y|d}|dkrVt}Wntk rrtj}YnX||_|dkrtj}||_ t |j|_ dS)Nrr) rKeyErrorrrrrrrr r rr)rrr kwargsrrrrrrs&  zCacheMiddleware.__init__)NN)r/r0r1r2rrrrrr8sr8N)r2 django.confrdjango.core.cacherrdjango.utils.cacherrrrr django.utils.deprecationr r r3r8rrrr,s  :+