1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
{- 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.
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Utility.DirWatcher where
import Utility.Types.DirWatcher
#if WITH_INOTIFY
import qualified Utility.INotify as INotify
import qualified System.INotify as INotify
import Utility.ThreadScheduler
#endif
#if WITH_KQUEUE
import qualified Utility.Kqueue as Kqueue
#endif
type Pruner = FilePath -> Bool
canWatch :: Bool
#if (WITH_INOTIFY || WITH_KQUEUE)
canWatch = True
#else
#if defined linux_HOST_OS
#warning "Building without inotify support"
#endif
canWatch = False
#endif
/* With inotify, discrete events will be received when making multiple changes
* to the same filename. For example, adding it, deleting it, and adding it
* again will be three events.
*
* OTOH, with kqueue, often only one event is received, indicating the most
* recent state of the file.
*/
eventsCoalesce :: Bool
#if WITH_INOTIFY
eventsCoalesce = False
#else
#if WITH_KQUEUE
eventsCoalesce = True
#else
eventsCoalesce = undefined
#endif
#endif
/* 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.
*
* 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
closingTracked = True
#else
#if WITH_KQUEUE
closingTracked = False
#else
closingTracked = undefined
#endif
#endif
#if WITH_INOTIFY
watchDir :: FilePath -> Pruner -> WatchHooks -> (IO () -> IO ()) -> IO ()
watchDir dir prune hooks runstartup = INotify.withINotify $ \i -> do
runstartup $ INotify.watchDir i dir prune hooks
waitForTermination -- Let the inotify thread run.
#else
#if WITH_KQUEUE
watchDir :: FilePath -> Pruner -> WatchHooks -> (IO Kqueue.Kqueue -> IO Kqueue.Kqueue) -> IO ()
watchDir dir ignored hooks runstartup = do
kq <- runstartup $ Kqueue.initKqueue dir ignored
Kqueue.runHooks kq hooks
#else
watchDir :: FilePath -> Pruner -> WatchHooks -> (IO () -> IO ()) -> IO ()
watchDir = undefined
#endif
#endif
|
