io-throttle (empty) → 0.1.0

raw patch · 5 files changed

+110/−0 lines, 5 filesdep +SafeSemaphoredep +basedep +io-throttlesetup-changed

Dependencies added: SafeSemaphore, base, io-throttle, threads

Files

• LICENSE +20/−0
• Setup.hs +2/−0
• io-throttle.cabal +38/−0
• src/Control/Concurrent/Throttle.hs +33/−0
• test/Main.hs +17/−0

@@ -0,0 +1,20 @@+Copyright (c) 2014 Rodrigo Setti++Permission is hereby granted, free of charge, to any person obtaining+a copy of this software and associated documentation files (the+"Software"), to deal in the Software without restriction, including+without limitation the rights to use, copy, modify, merge, publish,+distribute, sublicense, and/or sell copies of the Software, and to+permit persons to whom the Software is furnished to do so, subject to+the following conditions:++The above copyright notice and this permission notice shall be included+in all copies or substantial portions of the Software.++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

@@ -0,0 +1,38 @@+name          : io-throttle+version       : 0.1.0+synopsis      : Limit number of IO actions started per second+homepage      : http://github.com/rodrigosetti/io-throttle+license       : MIT+license-file  : LICENSE+copyright     : (c) 2014, Rodrigo Setti+author        : Rodrigo Setti+maintainer    : rodrigosetti@gmail.com+category      : Concurrency+build-type    : Simple+cabal-version : >=1.10+description   :+     Limit the number of tasks started per second. The throttle function will+     run all actions concurrently but only starting a certain number per+     second. It will wait for all tasks and return the results in a list.++source-repository head+  type     : git+  location : git@github.com:rodrigosetti/io-throttle.git++library+  exposed-modules  : Control.Concurrent.Throttle+  build-depends    : base          == 4.*+                   , threads       == 0.5.*+                   , SafeSemaphore == 0.10.*+  hs-source-dirs   : src+  default-language : Haskell2010+  ghc-options      : -Wall++test-suite test-io-threads+    default-language : Haskell2010+    hs-source-dirs   : test+    main-is          : Main.hs+    type             : exitcode-stdio-1.0+    build-depends    : base       == 4.*+                     , io-throttle+

@@ -0,0 +1,33 @@+{-|+Module      : Control.Concurrent.Throttle+Description : Limit the number of IO actions per second+Copyright   : (c) 2014, Rodrigo Setti+License     : MIT+Maintainer  : rodrigosetti@gmail.com+Stability   : experimental+Portability : POSIX+-}+module Control.Concurrent.Throttle (throttle) where++import           Control.Concurrent+import           Control.Concurrent.MSemN+import qualified Control.Concurrent.Thread as Thread+import           Control.Exception+import           Control.Monad++-- | Limit the number of @tasks@ started per second. @throttle@ will run all+--   actions concurrently but only starting a certain number per second. It+--   will wait for all tasks and return the results in a list.+throttle :: Int     -- ^ number of tasks per second (TPS)+         -> [IO a]  -- ^ the tasks to run concurrently but limited by TPS+         -> IO [a]  -- ^ the tasks results+throttle tps tasks =+    do sem   <- new tps+       let runTask task    = liftM snd $ wait sem 1 >> Thread.forkIO task+           timeResetWorker = forever $ threadDelay 1000000 >> signalF sem (\i -> (tps-i, ()))+           runAllTasks     = mapM runTask tasks+       mapM Thread.result =<< sequence =<< bracket (forkIO timeResetWorker)+                                                   killThread+                                                   (const runAllTasks)++

@@ -0,0 +1,17 @@+module Main where++import Control.Concurrent+import Control.Concurrent.Throttle+import Control.Monad++main :: IO ()+main = do res <- throttle 5 tasks+          putStrLn "-------------"+          forM_ res print+  where+    tasks = map performTask ([1..100] :: [Int])+    performTask i = do putStrLn $ "task start " ++ show i+                       threadDelay $ i * 10000+                       putStrLn $ "task done " ++ show i+                       return i+