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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.

é    )Úsettings)ÚDEFAULT_CACHE_ALIASÚcaches)Úget_cache_keyÚget_max_ageÚhas_vary_headerÚlearn_cache_keyÚpatch_response_headers)ÚMiddlewareMixinc                   @   s*   e Zd ZdZd	dd„Zdd„ Zdd„ ZdS )
Ú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.
    Nc                 C   s.   t j| _t j| _t j| _t| j | _|| _	d S ©N)
r   ÚCACHE_MIDDLEWARE_SECONDSÚcache_timeoutÚCACHE_MIDDLEWARE_KEY_PREFIXÚ
key_prefixÚCACHE_MIDDLEWARE_ALIASÚcache_aliasr   ÚcacheÚget_response©Úselfr   © r   úT/var/www/html/myproject/venv/lib/python3.10/site-packages/django/middleware/cache.pyÚ__init__@   s
   
zUpdateCacheMiddleware.__init__c                 C   s   t |dƒo|jS )NÚ_cache_update_cache)Úhasattrr   ©r   ÚrequestÚresponser   r   r   Ú_should_update_cacheG   s   z*UpdateCacheMiddleware._should_update_cachec                    sæ   ˆ  ||¡s|S |js|jdvr|S |js|jrt|dƒr|S d| dd¡v r)|S t|ƒ‰ˆdu r5ˆj‰nˆdkr;|S t	|ˆƒ ˆrq|jdkrqt
||ˆˆjˆjd	�‰ t|d
ƒrit|jƒri| ‡ ‡‡fdd„¡ |S ˆj ˆ |ˆ¡ |S )zSet the cache, if needed.)éÈ   i0  ÚCookieÚprivatezCache-Controlr   Nr   r    ©r   Úrenderc                    s   ˆj  ˆ | ˆ¡S r   )r   Úset)Úr©Ú	cache_keyr   Útimeoutr   r   Ú<lambda>j   s    z8UpdateCacheMiddleware.process_response.<locals>.<lambda>)r   Ú	streamingÚstatus_codeÚCOOKIESÚcookiesr   Úgetr   r   r	   r   r   r   r   Úcallabler$   Úadd_post_render_callbackr%   r   r   r'   r   Úprocess_responseJ   s.   
ÿÿz&UpdateCacheMiddleware.process_responser   )Ú__name__Ú
__module__Ú__qualname__Ú__doc__r   r   r2   r   r   r   r   r   7   s
    
r   c                   @   s"   e Zd ZdZddd„Zdd„ ZdS )Ú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.
    Nc                 C   s&   t j| _t j| _t| j | _|| _d S r   )r   r   r   r   r   r   r   r   r   r   r   r   r   y   s   
z!FetchFromCacheMiddleware.__init__c                 C   s”   |j dvr
d|_dS t|| jd| jd�}|du rd|_dS | j |¡}|du r<|j dkr<t|| jd| jd�}| j |¡}|du rEd|_dS d|_|S )zn
        Check whether the page is already cached and return the cached
        version if available.
        )ÚGETÚHEADFNr8   r#   Tr9   )Úmethodr   r   r   r   r/   )r   r   r(   r   r   r   r   Úprocess_request   s    
z(FetchFromCacheMiddleware.process_requestr   )r3   r4   r5   r6   r   r;   r   r   r   r   r7   q   s    
r7   c                   @   s   e Zd ZdZddd„ZdS )ÚCacheMiddlewarezÌ
    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.
    Nc                 K   sš   || _ z|d }|d u rd}W n ty   tj}Y nw || _z|d }|d u r*t}W n ty7   tj}Y nw || _|d u rBtj}|| _	t
| j | _d S )Nr   Ú r   )r   ÚKeyErrorr   r   r   r   r   r   r   r   r   r   )r   r   r   Úkwargsr   r   r   r   r   r   £   s.   €
ÿ€
ÿzCacheMiddleware.__init__)NN)r3   r4   r5   r6   r   r   r   r   r   r<   œ   s    r<   N)r6   Údjango.confr   Údjango.core.cacher   r   Údjango.utils.cacher   r   r   r   r	   Údjango.utils.deprecationr
   r   r7   r<   r   r   r   r   Ú<module>   s    -:+