OSX FSEvents support

Needs work to deal with directory renames better; otherwise seems to
basically work.
This commit is contained in:
Joey Hess 2012-12-27 14:19:12 -05:00 committed by Joey Hess
parent 44665452a8
commit 7af958d92c
5 changed files with 120 additions and 18 deletions

View file

@ -1,7 +1,8 @@
{- generic directory watching interface
-
- Uses either inotify or kqueue to watch a directory (and subdirectories)
- for changes, and runs hooks for different sorts of events as they occur.
- Uses inotify, or kqueue, or fsevents to watch a directory
- (and subdirectories) for changes, and runs hooks for different
- sorts of events as they occur.
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
@ -22,11 +23,15 @@ import qualified System.INotify as INotify
import qualified Utility.Kqueue as Kqueue
import Control.Concurrent
#endif
#if WITH_FSEVENTS
import qualified Utility.FSEvents as FSEvents
import qualified System.OSX.FSEvents as FSEvents
#endif
type Pruner = FilePath -> Bool
canWatch :: Bool
#if (WITH_INOTIFY || WITH_KQUEUE)
#if (WITH_INOTIFY || WITH_KQUEUE || WITH_FSEVENTS)
canWatch = True
#else
#if defined linux_HOST_OS
@ -42,7 +47,7 @@ canWatch = False
- OTOH, with kqueue, often only one event is received, indicating the most
- recent state of the file. -}
eventsCoalesce :: Bool
#if WITH_INOTIFY
#if (WITH_INOTIFY || WITH_FSEVENTS)
eventsCoalesce = False
#else
#if WITH_KQUEUE
@ -55,12 +60,15 @@ eventsCoalesce = undefined
{- With inotify, file closing is tracked to some extent, so an add event
- will always be received for a file once its writer closes it, and
- (typically) not before. This may mean multiple add events for the same file.
-
- fsevents behaves similarly, although different event types are used for
- creating and modification of the file.
-
- OTOH, with kqueue, add events will often be received while a file is
- still being written to, and then no add event will be received once the
- writer closes it. -}
closingTracked :: Bool
#if WITH_INOTIFY
#if (WITH_INOTIFY || WITH_FSEVENTS)
closingTracked = True
#else
#if WITH_KQUEUE
@ -71,9 +79,11 @@ closingTracked = undefined
#endif
{- With inotify, modifications to existing files can be tracked.
- Kqueue does not support this. -}
- Kqueue does not support this.
- Fsevents generates events when an existing file is reopened and rewritten,
- but not necessarily when it's opened once and modified repeatedly. -}
modifyTracked :: Bool
#if WITH_INOTIFY
#if (WITH_INOTIFY || WITH_FSEVENTS)
modifyTracked = True
#else
#if WITH_KQUEUE
@ -83,9 +93,9 @@ modifyTracked = undefined
#endif
#endif
{- Starts a watcher thread. The runStartup action is passed a scanner action
{- Starts a watcher thread. The runstartup action is passed a scanner action
- to run, that will return once the initial directory scan is complete.
- Once runStartup returns, the watcher thread continues running,
- Once runstartup returns, the watcher thread continues running,
- and processing events. Returns a DirWatcherHandle that can be used
- to shutdown later. -}
#if WITH_INOTIFY
@ -103,11 +113,18 @@ watchDir dir prune hooks runstartup = do
kq <- runstartup $ Kqueue.initKqueue dir prune
forkIO $ Kqueue.runHooks kq hooks
#else
#if WITH_FSEVENTS
type DirWatcherHandle = FSEvents.EventStream
watchDir :: FilePath -> Pruner -> WatchHooks -> (IO FSEvents.EventStream -> IO FSEvents.EventStream) -> IO DirWatcherHandle
watchDir dir prune hooks runstartup =
runstartup $ FSEvents.watchDir dir prune hooks
#else
type DirWatcherHandle = ()
watchDir :: FilePath -> Pruner -> WatchHooks -> (IO () -> IO ()) -> IO DirWatcherHandle
watchDir = undefined
#endif
#endif
#endif
#if WITH_INOTIFY
stopWatchDir :: DirWatcherHandle -> IO ()
@ -117,7 +134,12 @@ stopWatchDir = INotify.killINotify
stopWatchDir :: DirWatcherHandle -> IO ()
stopWatchDir = killThread
#else
#if WITH_FSEVENTS
stopWatchDir :: DirWatcherHandle -> IO ()
stopWatchDir = FSEvents.eventStreamDestroy
#else
stopWatchDir :: DirWatcherHandle -> IO ()
stopWatchDir = undefined
#endif
#endif
#endif

65
Utility/FSEvents.hs Normal file
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@ -0,0 +1,65 @@
{- FSEvents interface
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.FSEvents where
import Common hiding (isDirectory)
import Utility.Types.DirWatcher
import System.OSX.FSEvents
import qualified System.Posix.Files as Files
import Data.Bits ((.&.))
watchDir :: FilePath -> (FilePath -> Bool) -> WatchHooks -> IO EventStream
watchDir dir ignored hooks = do
unlessM fileLevelEventsSupported $
error "Need at least OSX 10.7.0 for file-level FSEvents"
eventStreamCreate [dir] 1.0 True False True handle
where
handle evt
| not (hasflag eventFlagItemIsFile) = noop
| ignoredPath ignored (eventPath evt) = noop
| otherwise = do
{- More than one flag may be set, if events occurred
- close together.
-
- Order is important..
- If a file is added and then deleted, we'll see it's
- not present, and addHook won't run.
- OTOH, if a file is deleted and then re-added,
- the delHook will run first, followed by the addHook.
-}
{- Deletion events are received for both directories
- and files, with no way to differentiate between
- them. Deleting a directory always first yields
- events deleting its contents though, so we
- just always call delHook, and never delDirHook. -}
when (hasflag eventFlagItemRemoved) $
runhook delHook Nothing
{- TODO deal with moving whole directories -}
when (hasflag eventFlagItemCreated || hasflag eventFlagItemRenamed) $ do
ms <- getstatus $ eventPath evt
case ms of
Nothing -> noop
Just s
| Files.isSymbolicLink s ->
runhook addSymlinkHook ms
| Files.isRegularFile s ->
runhook addHook ms
| otherwise -> noop
when (hasflag eventFlagItemModified) $ do
ms <- getstatus $ eventPath evt
runhook modifyHook ms
where
getstatus = catchMaybeIO . getSymbolicLinkStatus
hasflag f = eventFlags evt .&. f /= 0
runhook h s = maybe noop (\a -> a (eventPath evt) s) (h hooks)
{- Check each component of the path to see if it's ignored. -}
ignoredPath :: (FilePath -> Bool) -> FilePath -> Bool
ignoredPath ignored = any ignored . map dropTrailingPathSeparator . splitPath