Simpoole

Documentation

data Pool m a

Pool of resources

mapPool :: (forall x. m x -> n x) -> Pool m a -> Pool n a

Lift a natural transformation m ~> n to Pool m ~> Pool n.

newUnlimitedPool

Arguments

:: (MonadConc m, MonadIO m)

=> m a

Resource creation

-> (a -> m ())

Resource destruction

-> NominalDiffTime

Maximum idle time (+-1s) after which a resource is destroyed

-> m (Pool m a)

Create a new pool that has no limit on how many resources it may create and hold.

newPool

Arguments

:: (MonadConc m, MonadIO m, MonadFail m)

=> m a

Resource creation

-> (a -> m ())

Resource destruction

-> Int

Maximum number of resources to exist at the same time

-> NominalDiffTime

Maximum idle time (+-1s) after which a resource is destroyed

-> m (Pool m a)

Similar to newUnlimitedPool but allows you to limit the number of resources that will exist at the same time. When all resources are currently in use, further resource acquisition will block until one is no longer in use.

withResource :: MonadMask m => Pool m a -> (a -> m r) -> m r

Use a resource from the pool.

poolMetrics :: Pool m a -> m (Metrics Natural)

Fetch pool metrics.

data Metrics a

Pool metrics

Constructors

Metrics

Fields

• metrics_createdResources :: a

  Total number of resources created

• metrics_destroyedResources :: a

  Total number of resources destroyed

• metrics_maxLiveResources :: a

  Maximum number of resources that were alive simultaneously

Instances

Functor Metrics

Defined in Simpoole

Methods

fmap :: (a -> b) -> Metrics a -> Metrics b

(<$) :: a -> Metrics b -> Metrics a

Foldable Metrics

Defined in Simpoole

Methods

fold :: Monoid m => Metrics m -> m

foldMap :: Monoid m => (a -> m) -> Metrics a -> m

foldMap' :: Monoid m => (a -> m) -> Metrics a -> m

foldr :: (a -> b -> b) -> b -> Metrics a -> b

foldr' :: (a -> b -> b) -> b -> Metrics a -> b

foldl :: (b -> a -> b) -> b -> Metrics a -> b

foldl' :: (b -> a -> b) -> b -> Metrics a -> b

foldr1 :: (a -> a -> a) -> Metrics a -> a

foldl1 :: (a -> a -> a) -> Metrics a -> a

toList :: Metrics a -> [a]

null :: Metrics a -> Bool

length :: Metrics a -> Int

elem :: Eq a => a -> Metrics a -> Bool

maximum :: Ord a => Metrics a -> a

minimum :: Ord a => Metrics a -> a

sum :: Num a => Metrics a -> a

product :: Num a => Metrics a -> a

Traversable Metrics

Defined in Simpoole

Methods

traverse :: Applicative f => (a -> f b) -> Metrics a -> f (Metrics b)

sequenceA :: Applicative f => Metrics (f a) -> f (Metrics a)

mapM :: Monad m => (a -> m b) -> Metrics a -> m (Metrics b)

sequence :: Monad m => Metrics (m a) -> m (Metrics a)

Show a => Show (Metrics a)

Defined in Simpoole

Methods

showsPrec :: Int -> Metrics a -> ShowS

show :: Metrics a -> String

showList :: [Metrics a] -> ShowS