Data.Disk.Swapper.Cache

Here is provided a Cache type class designed to generalize notion of cache currently used in Swapper.

Documentation

class Cache a v | a -> v where

First parameter of this class is actual cache type, the second is type of cached values. The cache should just hold an reference to those values that are meant to be kept in memory.

Methods

addValue :: a -> v -> IO (IO ())

This function is called when new value is about to be added to the structure using the cache. It returns another IO action used for "refreshing"; i.e. which should be called whenever associated value is accessed, so the cache can adapt.

Instances

Cache (NullCache a) a

Cache (ClockCache a) a

Cache (SomeCache v) v

addValueRef :: Cache a v => IORef a -> v -> IO (IO ())

Version of addValue, which works with a cache in IORef.

data SomeCache v

Constructors

forall c . Cache c v => SomeCache !c

Instances

Cache (SomeCache v) v

data ClockCache a

Provides standard clock cache with second chance mechanism.

Constructors

ClockCache

Fields

ccSize :: Int

ccData :: MVar [(IORef a, IORef Bool)]

Instances

Typeable1 ClockCache

Cache (ClockCache a) a

mkClockCache :: Int -> IO (ClockCache a)

data NullCache a

NullCache does not cache any values

Constructors

NullCache

Instances

Cache (NullCache a) a

nullCache :: SomeCache a