add simple client pool

periodic-client/periodic-client.cabal

@@ -16,6 +16,7 @@ cabal-version:       >=1.10
 library
   hs-source-dirs:      src
   exposed-modules:     Periodic.Client
+                     , Periodic.ClientPool
                      , Periodic.Job
                      , Periodic.Worker
 
@@ -29,6 +30,8 @@ library
                      , transformers
                      , lifted-base
                      , lifted-async
+
+                     , resource-pool
   default-language:    Haskell2010
 
 executable periodic

periodic-client/src/Periodic/Client.hs

@@ -47,7 +47,7 @@ import           Periodic.Utils               (getEpochTime)
 import           Periodic.Monad
 import           System.Timeout.Lifted        (timeout)
 
-type ClientT m     = PeriodicT m ()
+type ClientT m = PeriodicT m ()
 
 data ClientEnv m = ClientEnv
   { periodicEnv      :: Env m ()

periodic-client/src/Periodic/ClientPool.hs

@@ -0,0 +1,23 @@
+module Periodic.ClientPool
+  (
+    module Periodic.Client
+  , ClientEnv
+  , runClientT
+  , open
+  ) where
+
+import           Data.Pool          (Pool, createPool, withResource)
+import           Periodic.Client    hiding (ClientEnv, close, open, runClientT)
+import qualified Periodic.Client    as Client (ClientEnv, close, open,
+                                               runClientT)
+import           Periodic.Transport (Transport)
+
+type ClientEnv = Pool (Client.ClientEnv IO)
+
+runClientT :: ClientEnv -> ClientT IO a -> IO a
+runClientT pool m = withResource pool $ flip Client.runClientT m
+
+open
+  :: (Transport -> IO Transport) -> String -> Int -> IO ClientEnv
+open f h =
+  createPool (Client.open f h) (`Client.runClientT` Client.close) 1 5000