2066e90421
Note that I still need to think this through and make sure handling of open files is safe. This is just for testing purposes.
359 lines
11 KiB
Haskell
359 lines
11 KiB
Haskell
{- git-annex assistant tree watcher
|
|
-
|
|
- Copyright 2012-2013 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
{-# LANGUAGE DeriveDataTypeable, CPP #-}
|
|
|
|
module Assistant.Threads.Watcher (
|
|
watchThread,
|
|
WatcherControl(..),
|
|
checkCanWatch,
|
|
needLsof,
|
|
onAddSymlink,
|
|
runHandler,
|
|
) where
|
|
|
|
import Assistant.Common
|
|
import Assistant.DaemonStatus
|
|
import Assistant.Changes
|
|
import Assistant.Types.Changes
|
|
import Assistant.Alert
|
|
import Utility.DirWatcher
|
|
import Utility.DirWatcher.Types
|
|
import qualified Utility.Lsof as 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.Direct
|
|
import Annex.Content.Direct
|
|
import Annex.CatFile
|
|
import Annex.CheckIgnore
|
|
import Annex.Link
|
|
import Annex.FileMatcher
|
|
import Annex.ReplaceFile
|
|
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
|
|
import Data.Time.Clock
|
|
|
|
checkCanWatch :: Annex ()
|
|
checkCanWatch
|
|
| canWatch = do
|
|
#ifndef mingw32_HOST_OS
|
|
liftIO Lsof.setup
|
|
unlessM (liftIO (inPath "lsof") <||> Annex.getState Annex.force)
|
|
needLsof
|
|
#else
|
|
noop
|
|
#endif
|
|
| 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 WatcherControl = PauseWatcher | ResumeWatcher
|
|
deriving (Show, Eq, Typeable)
|
|
|
|
instance E.Exception WatcherControl
|
|
|
|
watchThread :: NamedThread
|
|
watchThread = namedThread "Watcher" $
|
|
ifM (liftAnnex $ annexAutoCommit <$> Annex.getGitConfig)
|
|
( runWatcher
|
|
, waitFor ResumeWatcher runWatcher
|
|
)
|
|
|
|
runWatcher :: Assistant ()
|
|
runWatcher = do
|
|
startup <- asIO1 startupScan
|
|
matcher <- liftAnnex largeFilesMatcher
|
|
direct <- liftAnnex isDirect
|
|
symlinkssupported <- liftAnnex $ coreSymlinks <$> Annex.getGitConfig
|
|
addhook <- hook $ if direct
|
|
then onAddDirect symlinkssupported matcher
|
|
else onAdd matcher
|
|
delhook <- hook onDel
|
|
addsymlinkhook <- hook $ onAddSymlink direct
|
|
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 :: WatcherControl -> 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 $ onDel' f
|
|
maybe noop recordChange =<< madeChange f RmChange
|
|
void $ liftIO cleanup
|
|
|
|
liftAnnex $ showAction "started"
|
|
liftIO $ putStrLn ""
|
|
|
|
modifyDaemonStatus_ $ \s -> s { scanComplete = True }
|
|
|
|
return (True, r)
|
|
|
|
{- Hardcoded ignores, passed to the DirWatcher so it can avoid looking
|
|
- at the entire .git directory. Does not include .gitignores. -}
|
|
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
|
|
|
|
unlessIgnored :: FilePath -> Assistant (Maybe Change) -> Assistant (Maybe Change)
|
|
unlessIgnored file a = ifM (liftAnnex $ checkIgnored file)
|
|
( noChange
|
|
, a
|
|
)
|
|
|
|
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 (normalize 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
|
|
where
|
|
normalize f
|
|
| "./" `isPrefixOf` file = drop 2 f
|
|
| otherwise = f
|
|
|
|
{- Small files are added to git as-is, while large ones go into the annex. -}
|
|
add :: FileMatcher -> FilePath -> Assistant (Maybe Change)
|
|
add bigfilematcher file = ifM (liftAnnex $ checkFileMatcher bigfilematcher file)
|
|
( pendingAddChange file
|
|
, do
|
|
liftAnnex $ Annex.Queue.addCommand "add"
|
|
[Params "--force --"] [file]
|
|
madeChange file AddFileChange
|
|
)
|
|
|
|
onAdd :: FileMatcher -> Handler
|
|
onAdd matcher file filestatus
|
|
| maybe False isRegularFile filestatus =
|
|
unlessIgnored file $
|
|
add matcher file
|
|
| otherwise = noChange
|
|
|
|
shouldRestage :: DaemonStatus -> Bool
|
|
shouldRestage ds = scanComplete ds || forceRestage ds
|
|
|
|
{- In direct mode, add events are received for both new files, and
|
|
- modified existing files.
|
|
-}
|
|
onAddDirect :: Bool -> FileMatcher -> Handler
|
|
onAddDirect symlinkssupported matcher file fs = do
|
|
v <- liftAnnex $ catKeyFile file
|
|
case (v, fs) of
|
|
(Just key, Just filestatus) ->
|
|
ifM (liftAnnex $ sameFileStatus key filestatus)
|
|
{- It's possible to get an add event for
|
|
- an existing file that is not
|
|
- really modified, but it might have
|
|
- just been deleted and been put back,
|
|
- so it symlink is restaged to make sure. -}
|
|
( ifM (shouldRestage <$> getDaemonStatus)
|
|
( do
|
|
link <- liftAnnex $ inRepo $ gitAnnexLink file key
|
|
addLink file link (Just key)
|
|
, noChange
|
|
)
|
|
, guardSymlinkStandin (Just key) $ do
|
|
debug ["changed direct", file]
|
|
liftAnnex $ changedDirect key file
|
|
add matcher file
|
|
)
|
|
_ -> unlessIgnored file $
|
|
guardSymlinkStandin Nothing $ do
|
|
debug ["add direct", file]
|
|
add matcher file
|
|
where
|
|
{- On a filesystem without symlinks, we'll get changes for regular
|
|
- files that git uses to stand-in for symlinks. Detect when
|
|
- this happens, and stage the symlink, rather than annexing the
|
|
- file. -}
|
|
guardSymlinkStandin mk a
|
|
| symlinkssupported = a
|
|
| otherwise = do
|
|
linktarget <- liftAnnex $ getAnnexLinkTarget file
|
|
case linktarget of
|
|
Nothing -> a
|
|
Just lt -> do
|
|
case fileKey $ takeFileName lt of
|
|
Nothing -> noop
|
|
Just key -> void $ liftAnnex $
|
|
addAssociatedFile key file
|
|
onAddSymlink' linktarget mk True file fs
|
|
|
|
{- 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 :: Bool -> Handler
|
|
onAddSymlink isdirect file filestatus = unlessIgnored file $ do
|
|
linktarget <- liftIO (catchMaybeIO $ readSymbolicLink file)
|
|
kv <- liftAnnex (Backend.lookupFile file)
|
|
onAddSymlink' linktarget (fmap fst kv) isdirect file filestatus
|
|
|
|
onAddSymlink' :: Maybe String -> Maybe Key -> Bool -> Handler
|
|
onAddSymlink' linktarget mk isdirect file filestatus = go mk
|
|
where
|
|
go (Just key) = do
|
|
when isdirect $
|
|
liftAnnex $ void $ addAssociatedFile key file
|
|
link <- liftAnnex $ inRepo $ gitAnnexLink file key
|
|
if linktarget == Just link
|
|
then ensurestaged (Just link) =<< getDaemonStatus
|
|
else do
|
|
unless isdirect $
|
|
liftAnnex $ replaceFile file $
|
|
makeAnnexLink link
|
|
addLink file link (Just key)
|
|
-- other symlink, not git-annex
|
|
go Nothing = ensurestaged linktarget =<< 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
|
|
| shouldRestage daemonstatus = addLink file link mk
|
|
| otherwise = case filestatus of
|
|
Just s
|
|
| not (afterLastDaemonRun (statusChangeTime s) daemonstatus) -> noChange
|
|
_ -> addLink file link mk
|
|
ensurestaged Nothing _ = noChange
|
|
|
|
{- For speed, tries to reuse the existing blob for symlink target. -}
|
|
addLink :: FilePath -> FilePath -> Maybe Key -> Assistant (Maybe Change)
|
|
addLink file link mk = do
|
|
debug ["add symlink", file]
|
|
liftAnnex $ do
|
|
v <- catObjectDetails $ Ref $ ':':file
|
|
case v of
|
|
Just (currlink, sha, _type)
|
|
| s2w8 link == L.unpack currlink ->
|
|
stageSymlink file sha
|
|
_ -> stageSymlink file =<< hashSymlink link
|
|
madeChange file $ LinkChange mk
|
|
|
|
onDel :: Handler
|
|
onDel file _ = do
|
|
debug ["file deleted", file]
|
|
liftAnnex $ onDel' file
|
|
madeChange file RmChange
|
|
|
|
onDel' :: FilePath -> Annex ()
|
|
onDel' file = do
|
|
whenM isDirect $ do
|
|
mkey <- catKeyFile file
|
|
case mkey of
|
|
Nothing -> noop
|
|
Just key -> void $ removeAssociatedFile key file
|
|
Annex.Queue.addUpdateIndex =<<
|
|
inRepo (Git.UpdateIndex.unstageFile file)
|
|
|
|
{- 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.
|
|
-
|
|
- This queues up a lot of RmChanges, which assists the Committer in
|
|
- pairing up renamed files when the directory was renamed. -}
|
|
onDelDir :: Handler
|
|
onDelDir dir _ = do
|
|
debug ["directory deleted", dir]
|
|
(fs, clean) <- liftAnnex $ inRepo $ LsFiles.deleted [dir]
|
|
|
|
liftAnnex $ mapM_ onDel' fs
|
|
|
|
-- Get the events queued up as fast as possible, so the
|
|
-- committer sees them all in one block.
|
|
now <- liftIO getCurrentTime
|
|
recordChanges $ map (\f -> Change now f RmChange) fs
|
|
|
|
void $ liftIO clean
|
|
liftAnnex Annex.Queue.flushWhenFull
|
|
noChange
|
|
|
|
{- Called when there's an error with inotify or kqueue. -}
|
|
onErr :: Handler
|
|
onErr msg _ = do
|
|
liftAnnex $ warning msg
|
|
void $ addAlert $ warningAlert "watcher" msg
|
|
noChange
|