Network.Wai.Middleware.Cache

Transparent front cache middleware for Wai.

Instead caching internal data, this middleware caches entire responses. Of course, this creates additional costs. However, the simplification of the internal structure and concentration of caching in the immediate vicinity of the request is more than redeem them.

 cache (debugBackend True)
       ourFrivolousApplication

Backend

type CacheBackend

Arguments

 = Application

Application

-> Request

Request

-> ResourceT IO (Maybe Response)

Abstract cache backend. Result may be Nothing you need to respond wirh status 304 - Not Modified.

data CacheBackendError

Cache backend can throw errors. For handle this, use, for example, Network.Wai.Middleware.Catch.

Constructors

CacheBackendError ByteString

Instances

Eq CacheBackendError

Show CacheBackendError

Typeable CacheBackendError

Exception CacheBackendError

Middleware

cache

Arguments

:: CacheBackend

Cache backend.

-> Middleware

Cache middleware. Use it with conjuction with CacheBackend.

 -- Simplest backend. Suggests @304 - Not Modified@ with site root.
 rootBackend app req = do 
     case rawPathInfo req of
         "/" -> return Nothing
         _ -> do
             res <- app req 
             return $ Just res