Safe Haskell	None
Language	Haskell2010

System.Cache.Internal.Interface

Description

Internal interface for the Cache handle. In general you are not interested in this module and should use public API from the System.Cache instead, unless:

you need to implement your own handle,
you need to use internal functions like remove,
you need to provide your own getClockTime implementation

Synopsis

data Handle a b = Handle {
- requestOrInternal :: Seconds -> a -> (a -> IO b) -> IO b
- remove :: a -> IO ()
- getClockTime :: IO Seconds
}
data Config = Config {
- configLongestAge :: Seconds
- configClock :: Clock
}

Documentation

data Handle a b Source #

The public interface for the cache values storage.

A storage is expected to provide the following properties:

If the function return succesfully then the result should be cached for a time period, All later calls should return the cached value.
In case of the concurrent actions an implementation should be the best effort to avoid reduntant calls

Constructors

Handle
Fields requestOrInternal :: Seconds -> a -> (a -> IO b) -> IO b runs an action `f` that takes a parameter `a` and stores successful result for time no longer than `s`. remove :: a -> IO () removes the result cached for input `a`. getClockTime :: IO Seconds finds current time.

data Config Source #

Configuration for Cache

See System.Cache.Internal.Interface for all details on the fields.

Constructors

Config
Fields configLongestAge :: Seconds The time that the value can be kept in cache. configClock :: Clock Type of the clock that is used by cache, by changing this parameter you can optimize your usage for the different use cases, see System.Clock.Seconds documentation for explanation of the choises.