{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TupleSections #-}
module Stack.FileWatch
( fileWatch
, fileWatchPoll
) where
import Control.Concurrent.STM (check)
import Stack.Prelude
import qualified Data.Map.Strict as Map
import qualified Data.Set as Set
import GHC.IO.Exception
import Path
import System.FSNotify
import System.IO (hPutStrLn, getLine)
fileWatch :: Handle
-> ((Set (Path Abs File) -> IO ()) -> IO ())
-> IO ()
fileWatch = fileWatchConf defaultConfig
fileWatchPoll :: Handle
-> ((Set (Path Abs File) -> IO ()) -> IO ())
-> IO ()
fileWatchPoll = fileWatchConf $ defaultConfig { confUsePolling = True }
fileWatchConf :: WatchConfig
-> Handle
-> ((Set (Path Abs File) -> IO ()) -> IO ())
-> IO ()
fileWatchConf cfg out inner = withManagerConf cfg $ \manager -> do
let putLn = hPutStrLn out
outputIsTerminal <- hIsTerminalDeviceOrMinTTY out
let withColor color str = putLn $ do
if outputIsTerminal
then concat [color, str, reset]
else str
allFiles <- newTVarIO Set.empty
dirtyVar <- newTVarIO True
watchVar <- newTVarIO Map.empty
let onChange event = atomically $ do
files <- readTVar allFiles
when (eventPath event `Set.member` files) (writeTVar dirtyVar True)
setWatched :: Set (Path Abs File) -> IO ()
setWatched files = do
atomically $ writeTVar allFiles $ Set.map toFilePath files
watch0 <- readTVarIO watchVar
let actions = Map.mergeWithKey
keepListening
stopListening
startListening
watch0
newDirs
watch1 <- forM (Map.toList actions) $ \(k, mmv) -> do
mv <- mmv
return $
case mv of
Nothing -> Map.empty
Just v -> Map.singleton k v
atomically $ writeTVar watchVar $ Map.unions watch1
where
newDirs = Map.fromList $ map (, ())
$ Set.toList
$ Set.map parent files
keepListening _dir listen () = Just $ return $ Just listen
stopListening = Map.map $ \f -> do
() <- f `catch` \ioe ->
case ioe_type ioe of
InvalidArgument -> return ()
_ -> throwIO ioe
return Nothing
startListening = Map.mapWithKey $ \dir () -> do
let dir' = fromString $ toFilePath dir
listen <- watchDir manager dir' (const True) onChange
return $ Just listen
let watchInput = do
line <- getLine
unless (line == "quit") $ do
case line of
"help" -> do
putLn ""
putLn "help: display this help"
putLn "quit: exit"
putLn "build: force a rebuild"
putLn "watched: display watched files"
"build" -> atomically $ writeTVar dirtyVar True
"watched" -> do
watch <- readTVarIO allFiles
mapM_ putLn (Set.toList watch)
"" -> atomically $ writeTVar dirtyVar True
_ -> putLn $ concat
[ "Unknown command: "
, show line
, ". Try 'help'"
]
watchInput
race_ watchInput $ forever $ do
atomically $ do
dirty <- readTVar dirtyVar
check dirty
eres <- tryAny $ inner setWatched
atomically $ writeTVar dirtyVar False
case eres of
Left e -> do
let color = case fromException e of
Just ExitSuccess -> green
_ -> red
withColor color $ show e
_ -> withColor green "Success! Waiting for next file change."
putLn "Type help for available commands. Press enter to force a rebuild."
green, red, reset :: String
green = "\ESC[32m"
red = "\ESC[31m"
reset = "\ESC[0m"