Network.Wai.Middleware.Cache.Redis

Redis backend for Network.Wai.Middleware.Cache.

This backend uses Database.Redis.Pile for low-lewel operations.

 cache
     (redisBackend 
         -- use defaults, DB 0 and "myprefix" 
         R.defaultConnectInfo 0 "myprefix"
         (const Nothing)    -- no expiration
         (const ["mytag"])  -- simply one tag "mytag"
         (rawPathInfo)      -- URL path as key 
         lookupETag         -- And find "If-None-Match"
     ) app -- our app

Cache backend

redisBackend

Arguments

:: ConnectInfo

Redis connection info.

-> Integer

Redis DB.

-> ByteString

Cache prefix for key and tags. See Database.Redis.Pile for details.

-> (Request -> Maybe Integer)

TTL extraction. Use Nothing for no expiration.

-> (Request -> [ByteString])

Tags extraction. See Database.Redis.Pile for details.

-> (Request -> ByteString)

Key extraction.

-> (Request -> Maybe ByteString)

ETag value extraction. To extract If-None-Match header use lookupETag. Use (const Nothing) for block 304-responses.

-> CacheBackend

Redis backend for Network.Wai.Middleware.Cache.

Except caching, this backend always adds ETag to Response headers with hexed SHA1 as value.

This backend can't cache files. Use routing or catch CacheBackendError

Helpers

lookupETag :: Request -> Maybe ByteString

Helper for extract If-None-Match header from Request.