93f2371e09
The latter is harder for me to remember, but avoids build failures in code used by the configure program.
507 lines
16 KiB
Haskell
507 lines
16 KiB
Haskell
{- git-annex file content managing
|
||
-
|
||
- Copyright 2010-2013 Joey Hess <joey@kitenet.net>
|
||
-
|
||
- Licensed under the GNU GPL version 3 or higher.
|
||
-}
|
||
|
||
{-# LANGUAGE CPP #-}
|
||
|
||
module Annex.Content (
|
||
inAnnex,
|
||
inAnnexSafe,
|
||
inAnnexCheck,
|
||
lockContent,
|
||
getViaTmp,
|
||
getViaTmpChecked,
|
||
getViaTmpUnchecked,
|
||
withTmp,
|
||
checkDiskSpace,
|
||
moveAnnex,
|
||
sendAnnex,
|
||
prepSendAnnex,
|
||
removeAnnex,
|
||
fromAnnex,
|
||
moveBad,
|
||
getKeysPresent,
|
||
saveState,
|
||
downloadUrl,
|
||
preseedTmp,
|
||
freezeContent,
|
||
thawContent,
|
||
cleanObjectLoc,
|
||
) where
|
||
|
||
import System.IO.Unsafe (unsafeInterleaveIO)
|
||
import System.PosixCompat.Files
|
||
|
||
import Common.Annex
|
||
import Logs.Location
|
||
import qualified Git
|
||
import qualified Annex
|
||
import qualified Annex.Queue
|
||
import qualified Annex.Branch
|
||
import Utility.DiskFree
|
||
import Utility.FileMode
|
||
import qualified Utility.Url as Url
|
||
import Types.Key
|
||
import Utility.DataUnits
|
||
import Utility.CopyFile
|
||
import Config
|
||
import Annex.Exception
|
||
import Git.SharedRepository
|
||
import Annex.Perms
|
||
import Annex.Link
|
||
import Annex.Content.Direct
|
||
import Annex.ReplaceFile
|
||
|
||
{- Checks if a given key's content is currently present. -}
|
||
inAnnex :: Key -> Annex Bool
|
||
inAnnex key = inAnnexCheck key $ liftIO . doesFileExist
|
||
|
||
{- Runs an arbitrary check on a key's content. -}
|
||
inAnnexCheck :: Key -> (FilePath -> Annex Bool) -> Annex Bool
|
||
inAnnexCheck key check = inAnnex' id False check key
|
||
|
||
{- Generic inAnnex, handling both indirect and direct mode.
|
||
-
|
||
- In direct mode, at least one of the associated files must pass the
|
||
- check. Additionally, the file must be unmodified.
|
||
-}
|
||
inAnnex' :: (a -> Bool) -> a -> (FilePath -> Annex a) -> Key -> Annex a
|
||
inAnnex' isgood bad check key = withObjectLoc key checkindirect checkdirect
|
||
where
|
||
checkindirect loc = do
|
||
whenM (fromRepo Git.repoIsUrl) $
|
||
error "inAnnex cannot check remote repo"
|
||
check loc
|
||
checkdirect [] = return bad
|
||
checkdirect (loc:locs) = do
|
||
r <- check loc
|
||
if isgood r
|
||
then ifM (goodContent key loc)
|
||
( return r
|
||
, checkdirect locs
|
||
)
|
||
else checkdirect locs
|
||
|
||
{- A safer check; the key's content must not only be present, but
|
||
- is not in the process of being removed. -}
|
||
inAnnexSafe :: Key -> Annex (Maybe Bool)
|
||
inAnnexSafe = inAnnex' (fromMaybe False) (Just False) go
|
||
where
|
||
go f = liftIO $ openforlock f >>= check
|
||
openforlock f = catchMaybeIO $
|
||
#ifndef mingw32_HOST_OS
|
||
openFd f ReadOnly Nothing defaultFileFlags
|
||
#else
|
||
return ()
|
||
#endif
|
||
check Nothing = return is_missing
|
||
check (Just h) = do
|
||
#ifndef mingw32_HOST_OS
|
||
v <- getLock h (ReadLock, AbsoluteSeek, 0, 0)
|
||
closeFd h
|
||
return $ case v of
|
||
Just _ -> is_locked
|
||
Nothing -> is_unlocked
|
||
#else
|
||
return is_unlocked
|
||
#endif
|
||
is_locked = Nothing
|
||
is_unlocked = Just True
|
||
is_missing = Just False
|
||
|
||
{- Content is exclusively locked while running an action that might remove
|
||
- it. (If the content is not present, no locking is done.) -}
|
||
lockContent :: Key -> Annex a -> Annex a
|
||
lockContent key a = do
|
||
#ifdef mingw32_HOST_OS
|
||
a
|
||
#else
|
||
file <- calcRepo $ gitAnnexLocation key
|
||
bracketIO (openforlock file >>= lock) unlock (const a)
|
||
where
|
||
{- Since files are stored with the write bit disabled, have
|
||
- to fiddle with permissions to open for an exclusive lock. -}
|
||
openforlock f = catchMaybeIO $ ifM (doesFileExist f)
|
||
( withModifiedFileMode f
|
||
(`unionFileModes` ownerWriteMode)
|
||
open
|
||
, open
|
||
)
|
||
where
|
||
open = openFd f ReadWrite Nothing defaultFileFlags
|
||
lock Nothing = return Nothing
|
||
lock (Just fd) = do
|
||
v <- tryIO $ setLock fd (WriteLock, AbsoluteSeek, 0, 0)
|
||
case v of
|
||
Left _ -> error "content is locked"
|
||
Right _ -> return $ Just fd
|
||
unlock Nothing = noop
|
||
unlock (Just l) = closeFd l
|
||
#endif
|
||
|
||
{- Runs an action, passing it a temporary filename to get,
|
||
- and if the action succeeds, moves the temp file into
|
||
- the annex as a key's content. -}
|
||
getViaTmp :: Key -> (FilePath -> Annex Bool) -> Annex Bool
|
||
getViaTmp = getViaTmpChecked (return True)
|
||
|
||
{- Like getViaTmp, but does not check that there is enough disk space
|
||
- for the incoming key. For use when the key content is already on disk
|
||
- and not being copied into place. -}
|
||
getViaTmpUnchecked :: Key -> (FilePath -> Annex Bool) -> Annex Bool
|
||
getViaTmpUnchecked = finishGetViaTmp (return True)
|
||
|
||
getViaTmpChecked :: Annex Bool -> Key -> (FilePath -> Annex Bool) -> Annex Bool
|
||
getViaTmpChecked check key action = do
|
||
tmp <- fromRepo $ gitAnnexTmpLocation key
|
||
|
||
-- Check that there is enough free disk space.
|
||
-- When the temp file already exists, count the space
|
||
-- it is using as free.
|
||
e <- liftIO $ doesFileExist tmp
|
||
alreadythere <- if e
|
||
then fromIntegral . fileSize <$> liftIO (getFileStatus tmp)
|
||
else return 0
|
||
ifM (checkDiskSpace Nothing key alreadythere)
|
||
( do
|
||
when e $ thawContent tmp
|
||
finishGetViaTmp check key action
|
||
, return False
|
||
)
|
||
|
||
finishGetViaTmp :: Annex Bool -> Key -> (FilePath -> Annex Bool) -> Annex Bool
|
||
finishGetViaTmp check key action = do
|
||
tmpfile <- prepTmp key
|
||
ifM (action tmpfile <&&> check)
|
||
( do
|
||
moveAnnex key tmpfile
|
||
logStatus key InfoPresent
|
||
return True
|
||
, do
|
||
-- the tmp file is left behind, in case caller wants
|
||
-- to resume its transfer
|
||
return False
|
||
)
|
||
|
||
prepTmp :: Key -> Annex FilePath
|
||
prepTmp key = do
|
||
tmp <- fromRepo $ gitAnnexTmpLocation key
|
||
createAnnexDirectory (parentDir tmp)
|
||
return tmp
|
||
|
||
{- Creates a temp file, runs an action on it, and cleans up the temp file. -}
|
||
withTmp :: Key -> (FilePath -> Annex a) -> Annex a
|
||
withTmp key action = do
|
||
tmp <- prepTmp key
|
||
res <- action tmp
|
||
liftIO $ nukeFile tmp
|
||
return res
|
||
|
||
{- Checks that there is disk space available to store a given key,
|
||
- in a destination (or the annex) printing a warning if not. -}
|
||
checkDiskSpace :: Maybe FilePath -> Key -> Integer -> Annex Bool
|
||
checkDiskSpace destination key alreadythere = do
|
||
reserve <- annexDiskReserve <$> Annex.getGitConfig
|
||
free <- liftIO . getDiskFree =<< dir
|
||
force <- Annex.getState Annex.force
|
||
case (free, keySize key) of
|
||
(Just have, Just need) -> do
|
||
let ok = (need + reserve <= have + alreadythere) || force
|
||
unless ok $
|
||
needmorespace (need + reserve - have - alreadythere)
|
||
return ok
|
||
_ -> return True
|
||
where
|
||
dir = maybe (fromRepo gitAnnexDir) return destination
|
||
needmorespace n =
|
||
warning $ "not enough free space, need " ++
|
||
roughSize storageUnits True n ++
|
||
" more" ++ forcemsg
|
||
forcemsg = " (use --force to override this check or adjust annex.diskreserve)"
|
||
|
||
{- Moves a key's content into .git/annex/objects/
|
||
-
|
||
- In direct mode, moves it to the associated file, or files.
|
||
-
|
||
- What if the key there already has content? This could happen for
|
||
- various reasons; perhaps the same content is being annexed again.
|
||
- Perhaps there has been a hash collision generating the keys.
|
||
-
|
||
- The current strategy is to assume that in this case it's safe to delete
|
||
- one of the two copies of the content; and the one already in the annex
|
||
- is left there, assuming it's the original, canonical copy.
|
||
-
|
||
- I considered being more paranoid, and checking that both files had
|
||
- the same content. Decided against it because A) users explicitly choose
|
||
- a backend based on its hashing properties and so if they're dealing
|
||
- with colliding files it's their own fault and B) adding such a check
|
||
- would not catch all cases of colliding keys. For example, perhaps
|
||
- a remote has a key; if it's then added again with different content then
|
||
- the overall system now has two different peices of content for that
|
||
- key, and one of them will probably get deleted later. So, adding the
|
||
- check here would only raise expectations that git-annex cannot truely
|
||
- meet.
|
||
-}
|
||
moveAnnex :: Key -> FilePath -> Annex ()
|
||
moveAnnex key src = withObjectLoc key storeobject storedirect
|
||
where
|
||
storeobject dest = ifM (liftIO $ doesFileExist dest)
|
||
( alreadyhave
|
||
, do
|
||
createContentDir dest
|
||
liftIO $ moveFile src dest
|
||
freezeContent dest
|
||
freezeContentDir dest
|
||
)
|
||
storeindirect = storeobject =<< calcRepo (gitAnnexLocation key)
|
||
|
||
{- In direct mode, the associated file's content may be locally
|
||
- modified. In that case, it's preserved. However, the content
|
||
- we're moving into the annex may be the only extant copy, so
|
||
- it's important we not lose it. So, when the key's content
|
||
- cannot be moved to any associated file, it's stored in indirect
|
||
- mode.
|
||
-}
|
||
storedirect = storedirect' storeindirect
|
||
storedirect' fallback [] = fallback
|
||
storedirect' fallback (f:fs) = do
|
||
thawContentDir =<< calcRepo (gitAnnexLocation key)
|
||
thawContent src
|
||
v <- isAnnexLink f
|
||
if (Just key == v)
|
||
then do
|
||
updateInodeCache key src
|
||
replaceFile f $ liftIO . moveFile src
|
||
forM_ fs $
|
||
addContentWhenNotPresent key f
|
||
else ifM (goodContent key f)
|
||
( storedirect' alreadyhave fs
|
||
, storedirect' fallback fs
|
||
)
|
||
|
||
alreadyhave = liftIO $ removeFile src
|
||
|
||
{- Runs an action to transfer an object's content.
|
||
-
|
||
- In direct mode, it's possible for the file to change as it's being sent.
|
||
- If this happens, runs the rollback action and returns False. The
|
||
- rollback action should remove the data that was transferred.
|
||
-}
|
||
sendAnnex :: Key -> Annex () -> (FilePath -> Annex Bool) -> Annex Bool
|
||
sendAnnex key rollback sendobject = go =<< prepSendAnnex key
|
||
where
|
||
go Nothing = return False
|
||
go (Just (f, checksuccess)) = do
|
||
r <- sendobject f
|
||
ifM checksuccess
|
||
( return r
|
||
, do
|
||
rollback
|
||
return False
|
||
)
|
||
|
||
{- Returns a file that contains an object's content,
|
||
- and an check to run after the transfer is complete.
|
||
-
|
||
- In direct mode, it's possible for the file to change as it's being sent,
|
||
- and the check detects this case and returns False.
|
||
-
|
||
- Note that the returned check action is, in some cases, run in the
|
||
- Annex monad of the remote that is receiving the object, rather than
|
||
- the sender. So it cannot rely on Annex state.
|
||
-}
|
||
prepSendAnnex :: Key -> Annex (Maybe (FilePath, Annex Bool))
|
||
prepSendAnnex key = withObjectLoc key indirect direct
|
||
where
|
||
indirect f = return $ Just (f, return True)
|
||
direct [] = return Nothing
|
||
direct (f:fs) = do
|
||
cache <- recordedInodeCache key
|
||
-- check that we have a good file
|
||
ifM (sameInodeCache f cache)
|
||
( return $ Just (f, sameInodeCache f cache)
|
||
, direct fs
|
||
)
|
||
|
||
{- Performs an action, passing it the location to use for a key's content.
|
||
-
|
||
- In direct mode, the associated files will be passed. But, if there are
|
||
- no associated files for a key, the indirect mode action will be
|
||
- performed instead. -}
|
||
withObjectLoc :: Key -> (FilePath -> Annex a) -> ([FilePath] -> Annex a) -> Annex a
|
||
withObjectLoc key indirect direct = ifM isDirect
|
||
( do
|
||
fs <- associatedFiles key
|
||
if null fs
|
||
then goindirect
|
||
else direct fs
|
||
, goindirect
|
||
)
|
||
where
|
||
goindirect = indirect =<< calcRepo (gitAnnexLocation key)
|
||
|
||
cleanObjectLoc :: Key -> Annex ()
|
||
cleanObjectLoc key = do
|
||
file <- calcRepo $ gitAnnexLocation key
|
||
unlessM crippledFileSystem $
|
||
void $ liftIO $ catchMaybeIO $ allowWrite $ parentDir file
|
||
liftIO $ removeparents file (3 :: Int)
|
||
where
|
||
removeparents _ 0 = noop
|
||
removeparents file n = do
|
||
let dir = parentDir file
|
||
maybe noop (const $ removeparents dir (n-1))
|
||
<=< catchMaybeIO $ removeDirectory dir
|
||
|
||
{- Removes a key's file from .git/annex/objects/
|
||
-
|
||
- In direct mode, deletes the associated files or files, and replaces
|
||
- them with symlinks. -}
|
||
removeAnnex :: Key -> Annex ()
|
||
removeAnnex key = withObjectLoc key remove removedirect
|
||
where
|
||
remove file = do
|
||
thawContentDir file
|
||
liftIO $ nukeFile file
|
||
removeInodeCache key
|
||
cleanObjectLoc key
|
||
removedirect fs = do
|
||
thawContentDir =<< calcRepo (gitAnnexLocation key)
|
||
cache <- recordedInodeCache key
|
||
removeInodeCache key
|
||
mapM_ (resetfile cache) fs
|
||
resetfile cache f = whenM (sameInodeCache f cache) $ do
|
||
l <- inRepo $ gitAnnexLink f key
|
||
top <- fromRepo Git.repoPath
|
||
cwd <- liftIO getCurrentDirectory
|
||
let top' = fromMaybe top $ absNormPath cwd top
|
||
let l' = relPathDirToFile top' (fromMaybe l $ absNormPath top' l)
|
||
replaceFile f $ makeAnnexLink l'
|
||
|
||
{- Moves a key's file out of .git/annex/objects/ -}
|
||
fromAnnex :: Key -> FilePath -> Annex ()
|
||
fromAnnex key dest = do
|
||
file <- calcRepo $ gitAnnexLocation key
|
||
thawContentDir file
|
||
thawContent file
|
||
liftIO $ moveFile file dest
|
||
cleanObjectLoc key
|
||
|
||
{- Moves a key out of .git/annex/objects/ into .git/annex/bad, and
|
||
- returns the file it was moved to. -}
|
||
moveBad :: Key -> Annex FilePath
|
||
moveBad key = do
|
||
src <- calcRepo $ gitAnnexLocation key
|
||
bad <- fromRepo gitAnnexBadDir
|
||
let dest = bad </> takeFileName src
|
||
createAnnexDirectory (parentDir dest)
|
||
thawContentDir src
|
||
liftIO $ moveFile src dest
|
||
cleanObjectLoc key
|
||
logStatus key InfoMissing
|
||
return dest
|
||
|
||
{- List of keys whose content exists in the annex. -}
|
||
getKeysPresent :: Annex [Key]
|
||
getKeysPresent = do
|
||
direct <- isDirect
|
||
dir <- fromRepo gitAnnexObjectDir
|
||
liftIO $ traverse direct (2 :: Int) dir
|
||
where
|
||
traverse direct depth dir = do
|
||
contents <- catchDefaultIO [] (dirContents dir)
|
||
if depth == 0
|
||
then do
|
||
contents' <- filterM (present direct) contents
|
||
let keys = mapMaybe (fileKey . takeFileName) contents'
|
||
continue keys []
|
||
else do
|
||
let deeper = traverse direct (depth - 1)
|
||
continue [] (map deeper contents)
|
||
continue keys [] = return keys
|
||
continue keys (a:as) = do
|
||
{- Force lazy traversal with unsafeInterleaveIO. -}
|
||
morekeys <- unsafeInterleaveIO a
|
||
continue (morekeys++keys) as
|
||
|
||
{- In indirect mode, look for the key. In direct mode,
|
||
- the inode cache file is only present when a key's content
|
||
- is present. -}
|
||
present False d = doesFileExist $ contentfile d
|
||
present True d = doesFileExist $ contentfile d ++ ".cache"
|
||
contentfile d = d </> takeFileName d
|
||
|
||
{- Things to do to record changes to content when shutting down.
|
||
-
|
||
- It's acceptable to avoid committing changes to the branch,
|
||
- especially if performing a short-lived action.
|
||
-}
|
||
saveState :: Bool -> Annex ()
|
||
saveState nocommit = doSideAction $ do
|
||
Annex.Queue.flush
|
||
unless nocommit $
|
||
whenM (annexAlwaysCommit <$> Annex.getGitConfig) $
|
||
Annex.Branch.commit "update"
|
||
|
||
{- Downloads content from any of a list of urls. -}
|
||
downloadUrl :: [Url.URLString] -> FilePath -> Annex Bool
|
||
downloadUrl urls file = go =<< annexWebDownloadCommand <$> Annex.getGitConfig
|
||
where
|
||
go Nothing = do
|
||
opts <- map Param . annexWebOptions <$> Annex.getGitConfig
|
||
headers <- getHttpHeaders
|
||
liftIO $ anyM (\u -> Url.download u headers opts file) urls
|
||
go (Just basecmd) = liftIO $ anyM (downloadcmd basecmd) urls
|
||
downloadcmd basecmd url =
|
||
boolSystem "sh" [Param "-c", Param $ gencmd url basecmd]
|
||
<&&> doesFileExist file
|
||
gencmd url = massReplace
|
||
[ ("%file", shellEscape file)
|
||
, ("%url", shellEscape url)
|
||
]
|
||
|
||
{- Copies a key's content, when present, to a temp file.
|
||
- This is used to speed up some rsyncs. -}
|
||
preseedTmp :: Key -> FilePath -> Annex Bool
|
||
preseedTmp key file = go =<< inAnnex key
|
||
where
|
||
go False = return False
|
||
go True = do
|
||
ok <- copy
|
||
when ok $ thawContent file
|
||
return ok
|
||
copy = ifM (liftIO $ doesFileExist file)
|
||
( return True
|
||
, do
|
||
s <- calcRepo $ gitAnnexLocation key
|
||
liftIO $ copyFileExternal s file
|
||
)
|
||
|
||
{- Blocks writing to an annexed file, and modifies file permissions to
|
||
- allow reading it, per core.sharedRepository setting. -}
|
||
freezeContent :: FilePath -> Annex ()
|
||
freezeContent file = unlessM crippledFileSystem $
|
||
liftIO . go =<< fromRepo getSharedRepository
|
||
where
|
||
go GroupShared = modifyFileMode file $
|
||
removeModes writeModes .
|
||
addModes [ownerReadMode, groupReadMode]
|
||
go AllShared = modifyFileMode file $
|
||
removeModes writeModes .
|
||
addModes readModes
|
||
go _ = modifyFileMode file $
|
||
removeModes writeModes .
|
||
addModes [ownerReadMode]
|
||
|
||
{- Allows writing to an annexed file that freezeContent was called on
|
||
- before. -}
|
||
thawContent :: FilePath -> Annex ()
|
||
thawContent file = unlessM crippledFileSystem $
|
||
liftIO . go =<< fromRepo getSharedRepository
|
||
where
|
||
go GroupShared = groupWriteRead file
|
||
go AllShared = groupWriteRead file
|
||
go _ = allowWrite file
|