diff options
Diffstat (limited to 'Utility/Inotify.hs')
| -rw-r--r-- | Utility/Inotify.hs | 32 |
1 files changed, 19 insertions, 13 deletions
diff --git a/Utility/Inotify.hs b/Utility/Inotify.hs index 7329b5122..ad0c21b22 100644 --- a/Utility/Inotify.hs +++ b/Utility/Inotify.hs @@ -15,7 +15,11 @@ import qualified System.Posix.Files as Files import System.IO.Error import Control.Exception (throw) -type Hook a = Maybe (a -> IO ()) +{- A hook is passed some value to act on. + - + - The Bool is False when we're in the intial scan of a directory tree, + - rather than having received a genuine inotify event. -} +type Hook a = Maybe (a -> Bool -> IO ()) data WatchHooks = WatchHooks { addHook :: Hook FilePath @@ -31,7 +35,7 @@ data WatchHooks = WatchHooks - made for different events. - - Inotify is weak at recursive directory watching; the whole directory - - tree must be walked and watches set explicitly for each subdirectory. + - tree must be scanned and watches set explicitly for each subdirectory. - - To notice newly created subdirectories, inotify is used, and - watches are registered for those directories. There is a race there; @@ -65,14 +69,14 @@ watchDir i dir ignored hooks void (addWatch i watchevents dir handler) `catchIO` failedaddwatch withLock lock $ - mapM_ walk =<< filter (not . dirCruft) <$> + mapM_ scan =<< filter (not . dirCruft) <$> getDirectoryContents dir where recurse d = watchDir i d ignored hooks -- Select only inotify events required by the enabled -- hooks, but always include Create so new directories can - -- be walked. + -- be scanned. watchevents = Create : addevents ++ delevents addevents | hashook addHook || hashook addSymlinkHook = [MoveIn, CloseWrite] @@ -81,15 +85,15 @@ watchDir i dir ignored hooks | hashook delHook || hashook delDirHook = [MoveOut, Delete] | otherwise = [] - walk f = unless (ignored f) $ do + scan f = unless (ignored f) $ do let fullf = indir f r <- catchMaybeIO $ getSymbolicLinkStatus fullf case r of Nothing -> return () Just s | Files.isDirectory s -> recurse fullf - | Files.isSymbolicLink s -> addSymlinkHook <@> f - | Files.isRegularFile s -> addHook <@> f + | Files.isSymbolicLink s -> addSymlinkHook <@?> f + | Files.isRegularFile s -> addHook <@?> f | otherwise -> return () -- Ignore creation events for regular files, which won't be @@ -105,9 +109,9 @@ watchDir i dir ignored hooks go (Closed { isDirectory = False, maybeFilePath = Just f }) = whenM (filetype Files.isRegularFile f) $ addHook <@> f - -- When a file or directory is moved in, walk it to add new + -- When a file or directory is moved in, scan it to add new -- stuff. - go (MovedIn { filePath = f }) = walk f + go (MovedIn { filePath = f }) = scan f go (MovedOut { isDirectory = isd, filePath = f }) | isd = delDirHook <@> f | otherwise = delHook <@> f @@ -124,9 +128,11 @@ watchDir i dir ignored hooks hashook h = isJust $ h hooks - h <@> f + runhook h f inscan | ignored f = noop - | otherwise = maybe noop (\a -> a $ indir f) (h hooks) + | otherwise = maybe noop (\a -> a (indir f) inscan) (h hooks) + h <@> f = runhook h f False + h <@?> f = runhook h f True indir f = dir </> f @@ -141,10 +147,10 @@ watchDir i dir ignored hooks Just hook -> tooManyWatches hook dir | otherwise = throw e -tooManyWatches :: (String -> IO ()) -> FilePath -> IO () +tooManyWatches :: (String -> Bool -> IO ()) -> FilePath -> IO () tooManyWatches hook dir = do sysctlval <- querySysctl [Param maxwatches] :: IO (Maybe Integer) - hook $ unlines $ basewarning : maybe withoutsysctl withsysctl sysctlval + hook (unlines $ basewarning : maybe withoutsysctl withsysctl sysctlval) False where maxwatches = "fs.inotify.max_user_watches" basewarning = "Too many directories to watch! (Not watching " ++ dir ++")" |