This module contains a mutable wrapping of an LRU in the IO monad, providing atomic access in a concurrent environment. All calls preserve the same semantics as those in Data.Cache.LRU, but perform updates in place.
This module contains the internal implementation details. It's
possible to put an AtomicLRU
into a bad state with this module.
It is highly recommended that the external interface,
Data.Cache.LRU.IO, be used instead.
- newtype AtomicLRU key val = C (MVar (LRU key val))
- newAtomicLRU :: Ord key => Maybe Int -> IO (AtomicLRU key val)
- fromList :: Ord key => Maybe Int -> [(key, val)] -> IO (AtomicLRU key val)
- toList :: Ord key => AtomicLRU key val -> IO [(key, val)]
- maxSize :: AtomicLRU key val -> IO (Maybe Int)
- insert :: Ord key => key -> val -> AtomicLRU key val -> IO ()
- lookup :: Ord key => key -> AtomicLRU key val -> IO (Maybe val)
- delete :: Ord key => key -> AtomicLRU key val -> IO (Maybe val)
- pop :: Ord key => AtomicLRU key val -> IO (Maybe (key, val))
- size :: AtomicLRU key val -> IO Int
- modifyMVar_' :: MVar a -> (a -> IO a) -> IO ()
- modifyMVar' :: MVar a -> (a -> IO (a, b)) -> IO b
Documentation
Make a new AtomicLRU that will not grow beyond the optional maximum size, if specified.
Build a new LRU from the optional maximum size and list of
contents. See fromList
for the semantics.
toList :: Ord key => AtomicLRU key val -> IO [(key, val)]Source
Retrieve a list view of an AtomicLRU. See toList
for the
semantics.
insert :: Ord key => key -> val -> AtomicLRU key val -> IO ()Source
Insert a key/value pair into an AtomicLRU. See insert
for
the semantics.
lookup :: Ord key => key -> AtomicLRU key val -> IO (Maybe val)Source
Look up a key in an AtomicLRU. See lookup
for the
semantics.
delete :: Ord key => key -> AtomicLRU key val -> IO (Maybe val)Source
Remove an item from an AtomicLRU. Returns the value for the removed key, if it was present
pop :: Ord key => AtomicLRU key val -> IO (Maybe (key, val))Source
Remove the least-recently accessed item from an AtomicLRU. Returns the (key, val) pair removed, if one was present.
size :: AtomicLRU key val -> IO IntSource
Returns the number of elements the AtomicLRU currently contains.
modifyMVar_' :: MVar a -> (a -> IO a) -> IO ()Source
A version of modifyMVar_
that forces the result of the
function application to WHNF.
modifyMVar' :: MVar a -> (a -> IO (a, b)) -> IO bSource
A version of modifyMVar
that forces the result of the
function application to WHNF.