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authorPavan Rikhi <pavan.rikhi@gmail.com>2018-03-17 22:48:24 -0400
committerjao <jao@gnu.org>2018-11-21 21:41:35 +0000
commit4d1402a1a7d87767267d48a77998e4fb13395b31 (patch)
tree17fd6160dc1fa9c8a0676a94bcf8d19b551c655c /src/Xmobar/Plugins/BufferedPipeReader.hs
parent9e2a5c7daddf683d4be7c318aefed3da3ea7a89a (diff)
downloadxmobar-4d1402a1a7d87767267d48a77998e4fb13395b31.tar.gz
xmobar-4d1402a1a7d87767267d48a77998e4fb13395b31.tar.bz2
Split Modules into Library & Executable Structure
Move the Main module to a new `app` directory. All other modules have been nested under the `Xmobar` name. Lots of module headers & imports were updated.
Diffstat (limited to 'src/Xmobar/Plugins/BufferedPipeReader.hs')
-rw-r--r--src/Xmobar/Plugins/BufferedPipeReader.hs87
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diff --git a/src/Xmobar/Plugins/BufferedPipeReader.hs b/src/Xmobar/Plugins/BufferedPipeReader.hs
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+-----------------------------------------------------------------------------
+-- |
+-- Module : Plugins.BufferedPipeReader
+-- Copyright : (c) Jochen Keil
+-- License : BSD-style (see LICENSE)
+--
+-- Maintainer : Jochen Keil <jochen dot keil at gmail dot com>
+-- Stability : unstable
+-- Portability : unportable
+--
+-- A plugin for reading (temporarily) from named pipes with reset
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.Plugins.BufferedPipeReader where
+
+import Control.Monad(forM_, when, void)
+import Control.Concurrent
+import Control.Concurrent.STM
+import System.IO
+import System.IO.Unsafe(unsafePerformIO)
+
+import Xmobar.Environment
+import Xmobar.Plugins
+import Xmobar.Signal
+
+data BufferedPipeReader = BufferedPipeReader String [(Int, Bool, String)]
+ deriving (Read, Show)
+
+{-# NOINLINE signal #-}
+signal :: MVar SignalType
+signal = unsafePerformIO newEmptyMVar
+
+instance Exec BufferedPipeReader where
+ alias ( BufferedPipeReader a _ ) = a
+
+ trigger br@( BufferedPipeReader _ _ ) sh =
+ takeMVar signal >>= sh . Just >> trigger br sh
+
+ start ( BufferedPipeReader _ ps ) cb = do
+
+ (chan, str, rst) <- initV
+ forM_ ps $ \p -> forkIO $ reader p chan
+ writer chan str rst
+
+ where
+ initV :: IO ( TChan (Int, Bool, String), TVar (Maybe String), TVar Bool )
+ initV = atomically $ do
+ tc <- newTChan
+ ts <- newTVar Nothing
+ tb <- newTVar False
+ return (tc, ts, tb)
+
+ reader :: (Int, Bool, FilePath) -> TChan (Int, Bool, String) -> IO ()
+ reader p@(to, tg, fp) tc = do
+ fp' <- expandEnv fp
+ openFile fp' ReadWriteMode >>= hGetLineSafe >>= \dt ->
+ atomically $ writeTChan tc (to, tg, dt)
+ reader p tc
+
+ writer :: TChan (Int, Bool, String)
+ -> TVar (Maybe String) -> TVar Bool -> IO ()
+ writer tc ts otb = do
+ (to, tg, dt, ntb) <- update
+ cb dt
+ when tg $ putMVar signal $ Reveal 0
+ when (to /= 0) $ sfork $ reset to tg ts ntb
+ writer tc ts ntb
+
+ where
+ sfork :: IO () -> IO ()
+ sfork f = void (forkIO f)
+
+ update :: IO (Int, Bool, String, TVar Bool)
+ update = atomically $ do
+ (to, tg, dt) <- readTChan tc
+ when (to == 0) $ writeTVar ts $ Just dt
+ writeTVar otb False
+ tb <- newTVar True
+ return (to, tg, dt, tb)
+
+ reset :: Int -> Bool -> TVar (Maybe String) -> TVar Bool -> IO ()
+ reset to tg ts tb = do
+ threadDelay ( to * 100 * 1000 )
+ readTVarIO tb >>= \b -> when b $ do
+ when tg $ putMVar signal $ Hide 0
+ readTVarIO ts >>= maybe (return ()) cb