287 lines
8.4 KiB
Haskell
287 lines
8.4 KiB
Haskell
{- git-annex assistant tree watcher
|
|
-
|
|
- Copyright 2012 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
{-# LANGUAGE DeriveDataTypeable, CPP #-}
|
|
|
|
module Assistant.Threads.Watcher (
|
|
watchThread,
|
|
WatcherException(..),
|
|
checkCanWatch,
|
|
needLsof,
|
|
onAddSymlink,
|
|
runHandler,
|
|
) where
|
|
|
|
import Assistant.Common
|
|
import Assistant.DaemonStatus
|
|
import Assistant.Changes
|
|
import Assistant.Types.Changes
|
|
import Assistant.TransferQueue
|
|
import Assistant.Alert
|
|
import Assistant.Drop
|
|
import Logs.Transfer
|
|
import Utility.DirWatcher
|
|
import Utility.Types.DirWatcher
|
|
import Utility.Lsof
|
|
import qualified Annex
|
|
import qualified Annex.Queue
|
|
import qualified Git
|
|
import qualified Git.UpdateIndex
|
|
import qualified Git.LsFiles as LsFiles
|
|
import qualified Backend
|
|
import Annex.Content
|
|
import Annex.Direct
|
|
import Annex.Content.Direct
|
|
import Annex.CatFile
|
|
import Annex.Link
|
|
import Git.Types
|
|
import Config
|
|
import Utility.ThreadScheduler
|
|
|
|
import Data.Bits.Utils
|
|
import Data.Typeable
|
|
import qualified Data.ByteString.Lazy as L
|
|
import qualified Control.Exception as E
|
|
|
|
checkCanWatch :: Annex ()
|
|
checkCanWatch
|
|
| canWatch = do
|
|
liftIO setupLsof
|
|
unlessM (liftIO (inPath "lsof") <||> Annex.getState Annex.force)
|
|
needLsof
|
|
| otherwise = error "watch mode is not available on this system"
|
|
|
|
needLsof :: Annex ()
|
|
needLsof = error $ unlines
|
|
[ "The lsof command is needed for watch mode to be safe, and is not in PATH."
|
|
, "To override lsof checks to ensure that files are not open for writing"
|
|
, "when added to the annex, you can use --force"
|
|
, "Be warned: This can corrupt data in the annex, and make fsck complain."
|
|
]
|
|
|
|
{- A special exception that can be thrown to pause or resume the watcher. -}
|
|
data WatcherException = PauseWatcher | ResumeWatcher
|
|
deriving (Show, Eq, Typeable)
|
|
|
|
instance E.Exception WatcherException
|
|
|
|
watchThread :: NamedThread
|
|
watchThread = namedThread "Watcher" $
|
|
ifM (liftAnnex $ annexAutoCommit <$> Annex.getGitConfig)
|
|
( runWatcher
|
|
, waitFor ResumeWatcher runWatcher
|
|
)
|
|
|
|
runWatcher :: Assistant ()
|
|
runWatcher = do
|
|
startup <- asIO1 startupScan
|
|
direct <- liftAnnex isDirect
|
|
addhook <- hook $ if direct then onAddDirect else onAdd
|
|
delhook <- hook onDel
|
|
addsymlinkhook <- hook onAddSymlink
|
|
deldirhook <- hook onDelDir
|
|
errhook <- hook onErr
|
|
let hooks = mkWatchHooks
|
|
{ addHook = addhook
|
|
, delHook = delhook
|
|
, addSymlinkHook = addsymlinkhook
|
|
, delDirHook = deldirhook
|
|
, errHook = errhook
|
|
}
|
|
handle <- liftIO $ watchDir "." ignored hooks startup
|
|
debug [ "watching", "."]
|
|
|
|
{- Let the DirWatcher thread run until signalled to pause it,
|
|
- then wait for a resume signal, and restart. -}
|
|
waitFor PauseWatcher $ do
|
|
liftIO $ stopWatchDir handle
|
|
waitFor ResumeWatcher runWatcher
|
|
where
|
|
hook a = Just <$> asIO2 (runHandler a)
|
|
|
|
waitFor :: WatcherException -> Assistant () -> Assistant ()
|
|
waitFor sig next = do
|
|
r <- liftIO $ (E.try pause :: IO (Either E.SomeException ()))
|
|
case r of
|
|
Left e -> case E.fromException e of
|
|
Just s
|
|
| s == sig -> next
|
|
_ -> noop
|
|
_ -> noop
|
|
where
|
|
pause = runEvery (Seconds 86400) noop
|
|
|
|
{- Initial scartup scan. The action should return once the scan is complete. -}
|
|
startupScan :: IO a -> Assistant a
|
|
startupScan scanner = do
|
|
liftAnnex $ showAction "scanning"
|
|
alertWhile' startupScanAlert $ do
|
|
r <- liftIO $ scanner
|
|
|
|
-- Notice any files that were deleted before
|
|
-- watching was started.
|
|
top <- liftAnnex $ fromRepo Git.repoPath
|
|
(fs, cleanup) <- liftAnnex $ inRepo $ LsFiles.deleted [top]
|
|
forM_ fs $ \f -> do
|
|
liftAnnex $ Annex.Queue.addUpdateIndex =<<
|
|
inRepo (Git.UpdateIndex.unstageFile f)
|
|
maybe noop recordChange =<< madeChange f RmChange
|
|
void $ liftIO $ cleanup
|
|
|
|
liftAnnex $ showAction "started"
|
|
liftIO $ putStrLn ""
|
|
|
|
modifyDaemonStatus_ $ \s -> s { scanComplete = True }
|
|
|
|
return (True, r)
|
|
|
|
ignored :: FilePath -> Bool
|
|
ignored = ig . takeFileName
|
|
where
|
|
ig ".git" = True
|
|
ig ".gitignore" = True
|
|
ig ".gitattributes" = True
|
|
#ifdef darwin_HOST_OS
|
|
ig ".DS_Store" = True
|
|
#endif
|
|
ig _ = False
|
|
|
|
type Handler = FilePath -> Maybe FileStatus -> Assistant (Maybe Change)
|
|
|
|
{- Runs an action handler, and if there was a change, adds it to the ChangeChan.
|
|
-
|
|
- Exceptions are ignored, otherwise a whole watcher thread could be crashed.
|
|
-}
|
|
runHandler :: Handler -> FilePath -> Maybe FileStatus -> Assistant ()
|
|
runHandler handler file filestatus = void $ do
|
|
r <- tryIO <~> handler file filestatus
|
|
case r of
|
|
Left e -> liftIO $ print e
|
|
Right Nothing -> noop
|
|
Right (Just change) -> do
|
|
-- Just in case the commit thread is not
|
|
-- flushing the queue fast enough.
|
|
liftAnnex $ Annex.Queue.flushWhenFull
|
|
recordChange change
|
|
|
|
onAdd :: Handler
|
|
onAdd file filestatus
|
|
| maybe False isRegularFile filestatus = pendingAddChange file
|
|
| otherwise = noChange
|
|
|
|
{- In direct mode, add events are received for both new files, and
|
|
- modified existing files. Or, in some cases, existing files that have not
|
|
- really been modified. -}
|
|
onAddDirect :: Handler
|
|
onAddDirect file fs = do
|
|
v <- liftAnnex $ catKeyFile file
|
|
case (v, fs) of
|
|
(Just key, Just filestatus) ->
|
|
ifM (liftAnnex $ sameFileStatus key filestatus)
|
|
( noChange
|
|
, do
|
|
liftAnnex $ changedDirect key file
|
|
pendingAddChange file
|
|
)
|
|
_ -> pendingAddChange file
|
|
|
|
{- A symlink might be an arbitrary symlink, which is just added.
|
|
- Or, if it is a git-annex symlink, ensure it points to the content
|
|
- before adding it.
|
|
-}
|
|
onAddSymlink :: Handler
|
|
onAddSymlink file filestatus = go =<< liftAnnex (Backend.lookupFile file)
|
|
where
|
|
go (Just (key, _)) = do
|
|
link <- liftAnnex $ calcGitLink file key
|
|
ifM ((==) (Just link) <$> liftIO (catchMaybeIO $ readSymbolicLink file))
|
|
( do
|
|
s <- getDaemonStatus
|
|
checkcontent key s
|
|
ensurestaged (Just link) s
|
|
, do
|
|
liftIO $ removeFile file
|
|
liftAnnex $ Backend.makeAnnexLink link file
|
|
checkcontent key =<< getDaemonStatus
|
|
addlink link
|
|
)
|
|
go Nothing = do -- other symlink
|
|
mlink <- liftIO (catchMaybeIO $ readSymbolicLink file)
|
|
ensurestaged mlink =<< getDaemonStatus
|
|
|
|
{- This is often called on symlinks that are already
|
|
- staged correctly. A symlink may have been deleted
|
|
- and being re-added, or added when the watcher was
|
|
- not running. So they're normally restaged to make sure.
|
|
-
|
|
- As an optimisation, during the startup scan, avoid
|
|
- restaging everything. Only links that were created since
|
|
- the last time the daemon was running are staged.
|
|
- (If the daemon has never ran before, avoid staging
|
|
- links too.)
|
|
-}
|
|
ensurestaged (Just link) daemonstatus
|
|
| scanComplete daemonstatus = addlink link
|
|
| otherwise = case filestatus of
|
|
Just s
|
|
| not (afterLastDaemonRun (statusChangeTime s) daemonstatus) -> noChange
|
|
_ -> addlink link
|
|
ensurestaged Nothing _ = noChange
|
|
|
|
{- For speed, tries to reuse the existing blob for symlink target. -}
|
|
addlink link = do
|
|
debug ["add symlink", file]
|
|
liftAnnex $ do
|
|
v <- catObjectDetails $ Ref $ ':':file
|
|
case v of
|
|
Just (currlink, sha)
|
|
| s2w8 link == L.unpack currlink ->
|
|
stageSymlink file sha
|
|
_ -> stageSymlink file =<< hashSymlink link
|
|
madeChange file LinkChange
|
|
|
|
{- When a new link appears, or a link is changed, after the startup
|
|
- scan, handle getting or dropping the key's content.
|
|
- Also, moving or copying a link may caused it be be transferred
|
|
- elsewhere, so check that too. -}
|
|
checkcontent key daemonstatus
|
|
| scanComplete daemonstatus = do
|
|
present <- liftAnnex $ inAnnex key
|
|
if present
|
|
then queueTransfers Next key (Just file) Upload
|
|
else queueTransfers Next key (Just file) Download
|
|
handleDrops present key (Just file) Nothing
|
|
| otherwise = noop
|
|
|
|
onDel :: Handler
|
|
onDel file _ = do
|
|
debug ["file deleted", file]
|
|
liftAnnex $
|
|
Annex.Queue.addUpdateIndex =<<
|
|
inRepo (Git.UpdateIndex.unstageFile file)
|
|
madeChange file RmChange
|
|
|
|
{- A directory has been deleted, or moved, so tell git to remove anything
|
|
- that was inside it from its cache. Since it could reappear at any time,
|
|
- use --cached to only delete it from the index.
|
|
-
|
|
- Note: This could use unstageFile, but would need to run another git
|
|
- command to get the recursive list of files in the directory, so rm is
|
|
- just as good. -}
|
|
onDelDir :: Handler
|
|
onDelDir dir _ = do
|
|
debug ["directory deleted", dir]
|
|
liftAnnex $ Annex.Queue.addCommand "rm"
|
|
[Params "--quiet -r --cached --ignore-unmatch --"] [dir]
|
|
madeChange dir RmDirChange
|
|
|
|
{- Called when there's an error with inotify or kqueue. -}
|
|
onErr :: Handler
|
|
onErr msg _ = do
|
|
liftAnnex $ warning msg
|
|
void $ addAlert $ warningAlert "watcher" msg
|
|
noChange
|