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{-# LANGUAGE RecordWildCards #-}
import Foreign.C.Types (CFloat(..))
import qualified Sound.JACK as Jack
import qualified Sound.JACK.Audio as Audio
import Options.Applicative
import Data.Maybe
import System.Directory
import System.FilePath
import System.Posix.Files
import System.Posix.IO
import System.Environment
import System.Process
import Control.Concurrent
import Control.Concurrent.MVar
import Control.Concurrent.Chan
import qualified Control.Monad.Trans.Class as Trans
import qualified Control.Monad.Exception.Synchronous as Sync
import Control.Exception
import System.IO.Error
import System.IO
import System.INotify
import Data.Char
import Data.Function
import Control.Monad
import Data.CaseInsensitive ( CI )
import qualified Data.CaseInsensitive as CI
data Options = Options
{ input :: String
, output :: String
, client :: String
, run :: Maybe String
, levelFiles :: [FilePath]
}
data Level = Lin Float | DB Float
instance Show Level where
show (Lin x) = show x
show (DB x) = (show x') ++ "dB"
where
x' = 20 * (logBase 10 x)
instance Read Level where
readsPrec i = map toL . readsPrec i
where
toL :: (Float, String) -> (Level, String)
toL (f, str)
| ((==) `on` CI.mk) prec unit = (DB $ 10 ** (0.05 * f), rest)
| otherwise = (Lin f, str)
where
prec = take lU str
rest = drop lU str
unit = "dB"
lU = length unit
optionParser :: Parser Options
optionParser = Options <$>
(fromMaybe "in" <$> optional (strOption ( long "input"
<> metavar "STRING"
)
)
)
<*> (fromMaybe "out" <$> optional (strOption ( long "output"
<> metavar "STRING"
)
)
)
<*> strOption ( long "client"
<> metavar "STRING"
)
<*> optional ( strOption ( long "run"
<> metavar "FILE"
)
)
<*> some (strArgument ( metavar "FILE..."
<> help "Files that contain levels to assume and synchronize"
)
)
initialLevel :: Level
initialLevel = Lin 0
watchedAttrs :: [EventVariety]
watchedAttrs = [ Modify
, Move
, MoveIn
, MoveOut
, MoveSelf
, Create
, Delete
, DeleteSelf
]
main :: IO ()
main = execParser opts >>= trivmix
where
opts = info (helper <*> optionParser)
( fullDesc
<> progDesc "Setup a JACK mixing input/output pair controlled by fifos in a state directory"
<> header "Trivmix - A trivial mixer"
)
trivmix :: Options -> IO ()
trivmix Options{..} = do
level <- newMVar initialLevel
let withFiles = foldl (.) id $ map (\f -> onStateFile f (show initialLevel ++ "\n")) levelFiles
withFiles $ withINotify $ \inotify -> do
handleFiles inotify level levelFiles
Jack.handleExceptions $
Jack.withClientDefault client $ \client' ->
Jack.withPort client' input $ \input' ->
Jack.withPort client' output $ \output' -> do
Trans.lift $ do
case run of
Nothing -> return ()
Just run' -> do
(_, _, _, ph) <- createProcess $ (proc run' [client ++ ":" ++ input, client ++ ":" ++ output]) { delegate_ctlc = True }
return ()
Audio.withProcessMono client' input' (mix level) output' $
Jack.withActivation client' $ Trans.lift Jack.waitForBreak
mix :: MVar Level -> CFloat -> IO CFloat
mix level input = do
level' <- readMVar level
return $ (CFloat $ toFloat level') * input
where
toFloat (Lin x) = x
toFloat (DB x) = x
handleFiles :: INotify -> MVar Level -> [FilePath] -> IO ()
handleFiles inotify level files = do
initLevel <- readMVar level
levelChanges <- (newChan :: IO (Chan Level))
let
handleFile file = do
levelChanges' <- dupChan levelChanges
forkIO $ forever $ do -- Broadcast level changes and update all files
readChan levelChanges' >>= writeLevel file
addWatch inotify watchedAttrs file (const $ readLevel levelChanges level file)
mapM handleFile files
forkIO $ forever $ do
readChan levelChanges >>= swapMVar level
return ()
return ()
onStateFile :: FilePath -> String -> IO a -> IO a
onStateFile file initial action = do
let directory = takeDirectory file
dirExists <- doesDirectoryExist directory
exists <- doesFileExist file
let acquireFile = case exists of
True -> return ()
False -> do
hPutStrLn stderr $ "Creating ‘" ++ file ++ "’ (file)"
createFile file fileMode >>= closeFd >> writeFile file initial
fileMode = foldl unionFileModes nullFileMode [ ownerReadMode
, ownerWriteMode
, groupReadMode
, groupWriteMode
]
releaseFile = case exists of
True -> return ()
False -> do
hPutStrLn stderr $ "Removing ‘" ++ file ++ "’ (file)"
removeFile file
acquireDir = case dirExists of
True -> return ()
False -> do
hPutStrLn stderr $ "Creating ‘" ++ directory ++ "’ (dir"
createDirectoryIfMissing True directory
releaseDir = case dirExists of
True -> return ()
False -> do
hPutStrLn stderr $ "Removing ‘" ++ directory ++ "’ (dir)"
removeDirectory directory
acquire = acquireDir >> acquireFile
release = releaseFile >> releaseDir
bracket_ acquire release action
readLevel :: Chan Level -> MVar Level -> FilePath -> IO ()
readLevel levelChan current file = catch action handler
where
action = do
level <- readFile file >>= readIO . stripSpace
oldLevel <- readMVar current
when (oldLevel /= level) $ do
writeChan levelChan level
hPutStrLn stderr $ "Detected new level: " ++ (show level)
handler e = if isUserError e
then do
hPutStrLn stderr $ "Could not parse new level from ‘" ++ file ++ "’ - overwriting."
readMVar current >>= writeLevel file
else throw e
stripSpace = reverse . stripSpace' . reverse . stripSpace'
stripSpace' [] = []
stripSpace' l@(x:xs) = if isSpace x
then stripSpace' xs
else l
writeLevel :: FilePath -> Level -> IO ()
writeLevel file level = do
hPutStrLn stderr $ "Writing out level ‘" ++ (show level) ++ "’ to ‘" ++ file ++ "’"
writeFile file (show level ++ "\n")
|
