connection-pool-0.2: Connection pool built on top of resource-pool and streaming-commons.

Copyright(c) 2014-2015, Peter Trško
Stabilityunstable (internal module)
PortabilityCPP, DeriveDataTypeable, DeriveGeneric, FlexibleInstances, MultiParamTypeClasses, NoImplicitPrelude, PolyKinds, StandaloneDeriving, TypeFamilies
Safe HaskellNone



Module defines type family of connection pools that is later specialised using type tags (phantom types) to specialize implementation of underlying ConnectionPool for various protocols.

Internal packages are here to provide access to internal definitions for library writers, but they should not be used in application code.

Preferably use qualified import, e.g.:

import qualified Data.ConnectionPool.Internal.TCP as Internal

Module introduced in version 0.2.



data family ConnectionPool :: k -> * Source

Family of connection pools parametrised by transport protocol.

Definition changed version 0.2 to be kind polymorphic (only on GHC >= 7.10) and became part of stable API by being moved in to Data.ConnectionPool.Family module.


HasConnectionPool HandlerParams Socket () (ConnectionPool * UnixClient) Source

Since version 0.2.

HasConnectionPool HandlerParams Socket SockAddr (ConnectionPool * TcpClient) Source

Since version 0.2.

Show (ConnectionPool * TcpClient) 
Show (ConnectionPool * UnixClient) 
Generic (ConnectionPool * TcpClient) 
Generic (ConnectionPool * UnixClient) 
data ConnectionPool * TcpClient = TcpConnectionPool (ConnectionPool HandlerParams Socket SockAddr) Source

Connection pool for TCP clients.

Definition changed in version 0.1.3 and 0.2. Instances for Generic and Show introduced in version 0.2.

data ConnectionPool * UnixClient = UnixConnectionPool (ConnectionPool HandlerParams Socket ()) Source

Connection pool for UNIX Socket clients.

Definition changed in version 0.1.3 and 0.2. Instances for Generic and Show introduced in version 0.2.

type Rep (ConnectionPool * TcpClient) 
type Rep (ConnectionPool * UnixClient) 

data TcpClient Source

Type tag used to specialize connection pool for TCP clients.

Instance for Generic introduced in version 0.2.

createTcpClientPool :: ResourcePoolParams -> ClientSettings -> IO (ConnectionPool TcpClient) Source

Create connection pool for TCP clients.

withTcpClientConnection :: (MonadBaseControl io m, io ~ IO) => ConnectionPool TcpClient -> (AppData -> m r) -> m r Source

Temporarily take a TCP connection from a pool, run client with it, and return it to the pool afterwards. For details how connections are allocated see withResource.

tryWithTcpClientConnection :: (MonadBaseControl io m, io ~ IO) => ConnectionPool TcpClient -> (AppData -> m r) -> m (Maybe r) Source

Similar to withConnection, but only performs action if a TCP connection could be taken from the pool without blocking. Otherwise, tryWithResource returns immediately with Nothing (ie. the action function is not called). Conversely, if a connection can be acquired from the pool without blocking, the action is performed and it's result is returned, wrapped in a Just.

Since version 0.2.

destroyAllTcpClientConnections :: ConnectionPool TcpClient -> IO () Source

Destroy all TCP connections that might be still open in a connection pool. This is useful when one needs to release all resources at once and not to wait for idle timeout to be reached.

For more details see destroyAllResources.

Since version