Control.Concurrent.Cache

Documentation

data CachedData a

fetch :: CachedData a -> IO a

Fetch data from a cache

fetchCached :: CachedData a -> IO (Maybe a)

Only fetch data if it has been cached.

createReadOnceCache

Arguments

:: IO a

Fetcher, the function that returns the data which should be cached.

-> IO (CachedData a)

Create a cache which will execute an (IO ()) function on demand a maximum of 1 times.

createTimedCache

Arguments

:: Int

Timeout in microseconds before the cache is erased, 0 to disable emptying of the cache

-> Bool

resetTimerOnRead, if true the timeout will be reset every time the cache is read, otherwise it will only be reset when the cached value is set.

-> IO a

Fetcher, the function that returns the data which should be cached. If Timeout is not set to zero, this function must be allowed to be called more than once.

-> IO (CachedData a)

Create a cache with a timeout from an (IO ()) function.