| Safe Haskell | Safe |
|---|---|
| Language | Haskell98 |
Data.Cache.LRU.IO
Description
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. All functions use a single atomic update of the backing structure.
The interface this module provides is opaque. If further control is desired, the Data.Cache.LRU.IO.Internal module can be used in combination with Data.Cache.LRU.Internal.
(This implementation uses an MVar for coarse locking. It's unclear if anything else would give better performance, given that many calls alter the head of the access list.)
- data AtomicLRU key val
- newAtomicLRU :: Ord key => Maybe Integer -> IO (AtomicLRU key val)
- fromList :: Ord key => Maybe Integer -> [(key, val)] -> IO (AtomicLRU key val)
- toList :: Ord key => AtomicLRU key val -> IO [(key, val)]
- maxSize :: AtomicLRU key val -> IO (Maybe Integer)
- 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
- modifyAtomicLRU :: (LRU key val -> LRU key val) -> AtomicLRU key val -> IO ()
- modifyAtomicLRU' :: (LRU key val -> IO (LRU key val)) -> AtomicLRU key val -> IO ()
Documentation
Make a new AtomicLRU that will not grow beyond the optional maximum size, if specified.
Arguments
| :: Ord key | |
| => Maybe Integer | the optional maximum size |
| -> [(key, val)] | |
| -> IO (AtomicLRU key val) |
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 Int Source
Returns the number of elements the AtomicLRU currently contains.