{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TypeSynonymInstances #-}
{-# LANGUAGE FlexibleInstances #-}
module System.FSNotify.Polling (
createPollManager
, PollManager(..)
, FileListener(..)
) where
import Control.Concurrent
import Control.Exception.Safe
import Control.Monad (forM_)
import Data.Map (Map)
import qualified Data.Map as Map
import Data.Maybe
import Data.Time.Clock (UTCTime)
import Data.Time.Clock.POSIX
import Prelude hiding (FilePath)
import System.Directory (doesDirectoryExist)
import System.FSNotify.Listener
import System.FSNotify.Path (findFilesAndDirs, canonicalizeDirPath)
import System.FSNotify.Types
import System.FilePath
import System.PosixCompat.Files
import System.PosixCompat.Types
data EventType = AddedEvent
| ModifiedEvent
| RemovedEvent
newtype WatchKey = WatchKey ThreadId deriving (WatchKey -> WatchKey -> Bool
(WatchKey -> WatchKey -> Bool)
-> (WatchKey -> WatchKey -> Bool) -> Eq WatchKey
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
$c== :: WatchKey -> WatchKey -> Bool
== :: WatchKey -> WatchKey -> Bool
$c/= :: WatchKey -> WatchKey -> Bool
/= :: WatchKey -> WatchKey -> Bool
Eq, Eq WatchKey
Eq WatchKey =>
(WatchKey -> WatchKey -> Ordering)
-> (WatchKey -> WatchKey -> Bool)
-> (WatchKey -> WatchKey -> Bool)
-> (WatchKey -> WatchKey -> Bool)
-> (WatchKey -> WatchKey -> Bool)
-> (WatchKey -> WatchKey -> WatchKey)
-> (WatchKey -> WatchKey -> WatchKey)
-> Ord WatchKey
WatchKey -> WatchKey -> Bool
WatchKey -> WatchKey -> Ordering
WatchKey -> WatchKey -> WatchKey
forall a.
Eq a =>
(a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
$ccompare :: WatchKey -> WatchKey -> Ordering
compare :: WatchKey -> WatchKey -> Ordering
$c< :: WatchKey -> WatchKey -> Bool
< :: WatchKey -> WatchKey -> Bool
$c<= :: WatchKey -> WatchKey -> Bool
<= :: WatchKey -> WatchKey -> Bool
$c> :: WatchKey -> WatchKey -> Bool
> :: WatchKey -> WatchKey -> Bool
$c>= :: WatchKey -> WatchKey -> Bool
>= :: WatchKey -> WatchKey -> Bool
$cmax :: WatchKey -> WatchKey -> WatchKey
max :: WatchKey -> WatchKey -> WatchKey
$cmin :: WatchKey -> WatchKey -> WatchKey
min :: WatchKey -> WatchKey -> WatchKey
Ord)
data WatchData = WatchData FilePath EventCallback
type WatchMap = Map WatchKey WatchData
data PollManager = PollManager {
PollManager -> MVar WatchMap
pollManagerWatchMap :: MVar WatchMap
, PollManager -> Int
pollManagerInterval :: Int
}
generateEvent :: UTCTime -> EventIsDirectory -> EventType -> FilePath -> Maybe Event
generateEvent :: UTCTime -> EventIsDirectory -> EventType -> FilePath -> Maybe Event
generateEvent UTCTime
timestamp EventIsDirectory
isDir EventType
AddedEvent FilePath
filePath = Event -> Maybe Event
forall a. a -> Maybe a
Just (FilePath -> UTCTime -> EventIsDirectory -> Event
Added FilePath
filePath UTCTime
timestamp EventIsDirectory
isDir)
generateEvent UTCTime
timestamp EventIsDirectory
isDir EventType
ModifiedEvent FilePath
filePath = Event -> Maybe Event
forall a. a -> Maybe a
Just (FilePath -> UTCTime -> EventIsDirectory -> Event
Modified FilePath
filePath UTCTime
timestamp EventIsDirectory
isDir)
generateEvent UTCTime
timestamp EventIsDirectory
isDir EventType
RemovedEvent FilePath
filePath = Event -> Maybe Event
forall a. a -> Maybe a
Just (FilePath -> UTCTime -> EventIsDirectory -> Event
Removed FilePath
filePath UTCTime
timestamp EventIsDirectory
isDir)
generateEvents :: UTCTime -> EventType -> [(FilePath, EventIsDirectory)] -> [Event]
generateEvents :: UTCTime -> EventType -> [(FilePath, EventIsDirectory)] -> [Event]
generateEvents UTCTime
timestamp EventType
eventType = ((FilePath, EventIsDirectory) -> Maybe Event)
-> [(FilePath, EventIsDirectory)] -> [Event]
forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe (\(FilePath
path, EventIsDirectory
isDir) -> UTCTime -> EventIsDirectory -> EventType -> FilePath -> Maybe Event
generateEvent UTCTime
timestamp EventIsDirectory
isDir EventType
eventType FilePath
path)
handleEvent :: EventCallback -> ActionPredicate -> Event -> IO ()
handleEvent :: EventCallback -> ActionPredicate -> EventCallback
handleEvent EventCallback
_ ActionPredicate
_ (Modified FilePath
_ UTCTime
_ EventIsDirectory
IsDirectory) = () -> IO ()
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
handleEvent EventCallback
callback ActionPredicate
actPred Event
event
| ActionPredicate
actPred Event
event = EventCallback
callback Event
event
| Bool
otherwise = () -> IO ()
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
pathModMap :: Bool -> FilePath -> IO (Map FilePath (UTCTime, EventIsDirectory))
pathModMap :: Bool -> FilePath -> IO (Map FilePath (UTCTime, EventIsDirectory))
pathModMap Bool
recursive FilePath
path = Bool -> FilePath -> IO [FilePath]
findFilesAndDirs Bool
recursive FilePath
path IO [FilePath]
-> ([FilePath] -> IO (Map FilePath (UTCTime, EventIsDirectory)))
-> IO (Map FilePath (UTCTime, EventIsDirectory))
forall a b. IO a -> (a -> IO b) -> IO b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= [FilePath] -> IO (Map FilePath (UTCTime, EventIsDirectory))
pathModMap'
where
pathModMap' :: [FilePath] -> IO (Map FilePath (UTCTime, EventIsDirectory))
pathModMap' :: [FilePath] -> IO (Map FilePath (UTCTime, EventIsDirectory))
pathModMap' [FilePath]
files = ([(FilePath, (UTCTime, EventIsDirectory))]
-> Map FilePath (UTCTime, EventIsDirectory)
forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList ([(FilePath, (UTCTime, EventIsDirectory))]
-> Map FilePath (UTCTime, EventIsDirectory))
-> ([Maybe (FilePath, (UTCTime, EventIsDirectory))]
-> [(FilePath, (UTCTime, EventIsDirectory))])
-> [Maybe (FilePath, (UTCTime, EventIsDirectory))]
-> Map FilePath (UTCTime, EventIsDirectory)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [Maybe (FilePath, (UTCTime, EventIsDirectory))]
-> [(FilePath, (UTCTime, EventIsDirectory))]
forall a. [Maybe a] -> [a]
catMaybes) ([Maybe (FilePath, (UTCTime, EventIsDirectory))]
-> Map FilePath (UTCTime, EventIsDirectory))
-> IO [Maybe (FilePath, (UTCTime, EventIsDirectory))]
-> IO (Map FilePath (UTCTime, EventIsDirectory))
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (FilePath -> IO (Maybe (FilePath, (UTCTime, EventIsDirectory))))
-> [FilePath] -> IO [Maybe (FilePath, (UTCTime, EventIsDirectory))]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM FilePath -> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
pathAndInfo [FilePath]
files
pathAndInfo :: FilePath -> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
pathAndInfo :: FilePath -> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
pathAndInfo FilePath
p = (IOException -> IO (Maybe (FilePath, (UTCTime, EventIsDirectory))))
-> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
-> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
forall (m :: * -> *) e a.
(HasCallStack, MonadCatch m, Exception e) =>
(e -> m a) -> m a -> m a
handle (\(IOException
_ :: IOException) -> Maybe (FilePath, (UTCTime, EventIsDirectory))
-> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe (FilePath, (UTCTime, EventIsDirectory))
forall a. Maybe a
Nothing) (IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
-> IO (Maybe (FilePath, (UTCTime, EventIsDirectory))))
-> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
-> IO (Maybe (FilePath, (UTCTime, EventIsDirectory)))
forall a b. (a -> b) -> a -> b
$ do
modTime <- FilePath -> IO UTCTime
getModificationTime FilePath
p
isDir <- doesDirectoryExist p
return $ Just (p, (modTime, if isDir then IsDirectory else IsFile))
pollPath :: Int -> Bool -> EventCallback -> FilePath -> ActionPredicate -> Map FilePath (UTCTime, EventIsDirectory) -> IO ()
pollPath :: Int
-> Bool
-> EventCallback
-> FilePath
-> ActionPredicate
-> Map FilePath (UTCTime, EventIsDirectory)
-> IO ()
pollPath Int
interval Bool
recursive EventCallback
callback FilePath
filePath ActionPredicate
actPred Map FilePath (UTCTime, EventIsDirectory)
oldPathMap = do
Int -> IO ()
threadDelay Int
interval
maybeNewPathMap <- (IOException
-> IO (Maybe (Map FilePath (UTCTime, EventIsDirectory))))
-> IO (Maybe (Map FilePath (UTCTime, EventIsDirectory)))
-> IO (Maybe (Map FilePath (UTCTime, EventIsDirectory)))
forall (m :: * -> *) e a.
(HasCallStack, MonadCatch m, Exception e) =>
(e -> m a) -> m a -> m a
handle (\(IOException
_ :: IOException) -> Maybe (Map FilePath (UTCTime, EventIsDirectory))
-> IO (Maybe (Map FilePath (UTCTime, EventIsDirectory)))
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe (Map FilePath (UTCTime, EventIsDirectory))
forall a. Maybe a
Nothing) (Map FilePath (UTCTime, EventIsDirectory)
-> Maybe (Map FilePath (UTCTime, EventIsDirectory))
forall a. a -> Maybe a
Just (Map FilePath (UTCTime, EventIsDirectory)
-> Maybe (Map FilePath (UTCTime, EventIsDirectory)))
-> IO (Map FilePath (UTCTime, EventIsDirectory))
-> IO (Maybe (Map FilePath (UTCTime, EventIsDirectory)))
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Bool -> FilePath -> IO (Map FilePath (UTCTime, EventIsDirectory))
pathModMap Bool
recursive FilePath
filePath)
case maybeNewPathMap of
Maybe (Map FilePath (UTCTime, EventIsDirectory))
Nothing -> Int
-> Bool
-> EventCallback
-> FilePath
-> ActionPredicate
-> Map FilePath (UTCTime, EventIsDirectory)
-> IO ()
pollPath Int
interval Bool
recursive EventCallback
callback FilePath
filePath ActionPredicate
actPred Map FilePath (UTCTime, EventIsDirectory)
oldPathMap
Just Map FilePath (UTCTime, EventIsDirectory)
newPathMap -> do
currentTime <- IO UTCTime
getCurrentTime
let deletedMap = Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
forall k a b. Ord k => Map k a -> Map k b -> Map k a
Map.difference Map FilePath (UTCTime, EventIsDirectory)
oldPathMap Map FilePath (UTCTime, EventIsDirectory)
newPathMap
createdMap = Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
forall k a b. Ord k => Map k a -> Map k b -> Map k a
Map.difference Map FilePath (UTCTime, EventIsDirectory)
newPathMap Map FilePath (UTCTime, EventIsDirectory)
oldPathMap
modifiedAndCreatedMap = ((UTCTime, EventIsDirectory)
-> (UTCTime, EventIsDirectory)
-> Maybe (UTCTime, EventIsDirectory))
-> Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
forall k a b.
Ord k =>
(a -> b -> Maybe a) -> Map k a -> Map k b -> Map k a
Map.differenceWith (UTCTime, EventIsDirectory)
-> (UTCTime, EventIsDirectory) -> Maybe (UTCTime, EventIsDirectory)
modifiedDifference Map FilePath (UTCTime, EventIsDirectory)
newPathMap Map FilePath (UTCTime, EventIsDirectory)
oldPathMap
modifiedMap = Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
-> Map FilePath (UTCTime, EventIsDirectory)
forall k a b. Ord k => Map k a -> Map k b -> Map k a
Map.difference Map FilePath (UTCTime, EventIsDirectory)
modifiedAndCreatedMap Map FilePath (UTCTime, EventIsDirectory)
createdMap
generateEvents' = UTCTime -> EventType -> [(FilePath, EventIsDirectory)] -> [Event]
generateEvents UTCTime
currentTime
handleEvents $ generateEvents' AddedEvent [(path, isDir) | (path, (_, isDir)) <- Map.toList createdMap]
handleEvents $ generateEvents' ModifiedEvent [(path, isDir) | (path, (_, isDir)) <- Map.toList modifiedMap]
handleEvents $ generateEvents' RemovedEvent [(path, isDir) | (path, (_, isDir)) <- Map.toList deletedMap]
pollPath interval recursive callback filePath actPred newPathMap
where
modifiedDifference :: (UTCTime, EventIsDirectory) -> (UTCTime, EventIsDirectory) -> Maybe (UTCTime, EventIsDirectory)
modifiedDifference :: (UTCTime, EventIsDirectory)
-> (UTCTime, EventIsDirectory) -> Maybe (UTCTime, EventIsDirectory)
modifiedDifference (UTCTime
newTime, EventIsDirectory
isDir1) (UTCTime
oldTime, EventIsDirectory
isDir2)
| UTCTime
oldTime UTCTime -> UTCTime -> Bool
forall a. Eq a => a -> a -> Bool
/= UTCTime
newTime Bool -> Bool -> Bool
|| EventIsDirectory
isDir1 EventIsDirectory -> EventIsDirectory -> Bool
forall a. Eq a => a -> a -> Bool
/= EventIsDirectory
isDir2 = (UTCTime, EventIsDirectory) -> Maybe (UTCTime, EventIsDirectory)
forall a. a -> Maybe a
Just (UTCTime
newTime, EventIsDirectory
isDir1)
| Bool
otherwise = Maybe (UTCTime, EventIsDirectory)
forall a. Maybe a
Nothing
handleEvents :: [Event] -> IO ()
handleEvents :: [Event] -> IO ()
handleEvents = EventCallback -> [Event] -> IO ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ (EventCallback -> ActionPredicate -> EventCallback
handleEvent EventCallback
callback ActionPredicate
actPred)
createPollManager :: Int -> IO PollManager
createPollManager :: Int -> IO PollManager
createPollManager Int
interval = MVar WatchMap -> Int -> PollManager
PollManager (MVar WatchMap -> Int -> PollManager)
-> IO (MVar WatchMap) -> IO (Int -> PollManager)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> WatchMap -> IO (MVar WatchMap)
forall a. a -> IO (MVar a)
newMVar WatchMap
forall k a. Map k a
Map.empty IO (Int -> PollManager) -> IO Int -> IO PollManager
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> Int -> IO Int
forall a. a -> IO a
forall (f :: * -> *) a. Applicative f => a -> f a
pure Int
interval
killWatchingThread :: WatchKey -> IO ()
killWatchingThread :: WatchKey -> IO ()
killWatchingThread (WatchKey ThreadId
threadId) = ThreadId -> IO ()
killThread ThreadId
threadId
killAndUnregister :: MVar WatchMap -> WatchKey -> IO ()
killAndUnregister :: MVar WatchMap -> WatchKey -> IO ()
killAndUnregister MVar WatchMap
mvarMap WatchKey
wk = do
_ <- MVar WatchMap -> (WatchMap -> IO WatchMap) -> IO WatchMap
forall a b. MVar a -> (a -> IO b) -> IO b
withMVar MVar WatchMap
mvarMap ((WatchMap -> IO WatchMap) -> IO WatchMap)
-> (WatchMap -> IO WatchMap) -> IO WatchMap
forall a b. (a -> b) -> a -> b
$ \WatchMap
m -> do
WatchKey -> IO ()
killWatchingThread WatchKey
wk
WatchMap -> IO WatchMap
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (WatchMap -> IO WatchMap) -> WatchMap -> IO WatchMap
forall a b. (a -> b) -> a -> b
$ WatchKey -> WatchMap -> WatchMap
forall k a. Ord k => k -> Map k a -> Map k a
Map.delete WatchKey
wk WatchMap
m
return ()
listen' :: Bool -> WatchConfig -> PollManager -> FilePath -> ActionPredicate -> EventCallback -> IO (IO ())
listen' :: Bool
-> WatchConfig
-> PollManager
-> FilePath
-> ActionPredicate
-> EventCallback
-> IO (IO ())
listen' Bool
isRecursive WatchConfig
_conf (PollManager MVar WatchMap
mvarMap Int
interval) FilePath
path ActionPredicate
actPred EventCallback
callback = do
path' <- FilePath -> IO FilePath
canonicalizeDirPath FilePath
path
pmMap <- pathModMap isRecursive path'
threadId <- forkIO $ pollPath interval isRecursive callback path' actPred pmMap
let wk = ThreadId -> WatchKey
WatchKey ThreadId
threadId
modifyMVar_ mvarMap $ return . Map.insert wk (WatchData path' callback)
return $ killAndUnregister mvarMap wk
instance FileListener PollManager Int where
initSession :: Int -> IO (Either Text PollManager)
initSession Int
interval = PollManager -> Either Text PollManager
forall a b. b -> Either a b
Right (PollManager -> Either Text PollManager)
-> IO PollManager -> IO (Either Text PollManager)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Int -> IO PollManager
createPollManager Int
interval
killSession :: PollManager -> IO ()
killSession (PollManager MVar WatchMap
mvarMap Int
_) = do
watchMap <- MVar WatchMap -> IO WatchMap
forall a. MVar a -> IO a
readMVar MVar WatchMap
mvarMap
forM_ (Map.keys watchMap) killWatchingThread
listen :: ListenFn PollManager Int
listen = Bool
-> WatchConfig
-> PollManager
-> FilePath
-> ActionPredicate
-> EventCallback
-> IO (IO ())
listen' Bool
False
listenRecursive :: ListenFn PollManager Int
listenRecursive = Bool
-> WatchConfig
-> PollManager
-> FilePath
-> ActionPredicate
-> EventCallback
-> IO (IO ())
listen' Bool
True
getModificationTime :: FilePath -> IO UTCTime
getModificationTime :: FilePath -> IO UTCTime
getModificationTime FilePath
p = EpochTime -> UTCTime
fromEpoch (EpochTime -> UTCTime)
-> (FileStatus -> EpochTime) -> FileStatus -> UTCTime
forall b c a. (b -> c) -> (a -> b) -> a -> c
. FileStatus -> EpochTime
modificationTime (FileStatus -> UTCTime) -> IO FileStatus -> IO UTCTime
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> FilePath -> IO FileStatus
getFileStatus FilePath
p
fromEpoch :: EpochTime -> UTCTime
fromEpoch :: EpochTime -> UTCTime
fromEpoch = POSIXTime -> UTCTime
posixSecondsToUTCTime (POSIXTime -> UTCTime)
-> (EpochTime -> POSIXTime) -> EpochTime -> UTCTime
forall b c a. (b -> c) -> (a -> b) -> a -> c
. EpochTime -> POSIXTime
forall a b. (Real a, Fractional b) => a -> b
realToFrac