git-annex/Annex/Content/Direct.hs
2014-02-03 10:08:28 -04:00

254 lines
8.4 KiB
Haskell

{- git-annex file content managing for direct mode
-
- Copyright 2012-2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Content.Direct (
associatedFiles,
associatedFilesRelative,
removeAssociatedFile,
removeAssociatedFileUnchecked,
removeAssociatedFiles,
addAssociatedFile,
goodContent,
recordedInodeCache,
updateInodeCache,
addInodeCache,
writeInodeCache,
compareInodeCaches,
compareInodeCachesWith,
sameInodeCache,
elemInodeCaches,
sameFileStatus,
removeInodeCache,
toInodeCache,
inodesChanged,
createInodeSentinalFile,
addContentWhenNotPresent,
) where
import Common.Annex
import qualified Annex
import Annex.Perms
import qualified Git
import Utility.Tmp
import Logs.Location
import Utility.InodeCache
import Utility.CopyFile
import Annex.ReplaceFile
import Annex.Link
{- Absolute FilePaths of Files in the tree that are associated with a key. -}
associatedFiles :: Key -> Annex [FilePath]
associatedFiles key = do
files <- associatedFilesRelative key
top <- fromRepo Git.repoPath
return $ map (top </>) files
{- List of files in the tree that are associated with a key, relative to
- the top of the repo. -}
associatedFilesRelative :: Key -> Annex [FilePath]
associatedFilesRelative key = do
mapping <- calcRepo $ gitAnnexMapping key
liftIO $ catchDefaultIO [] $ do
h <- openFile mapping ReadMode
fileEncoding h
lines <$> hGetContents h
{- Changes the associated files information for a key, applying a
- transformation to the list. Returns new associatedFiles value. -}
changeAssociatedFiles :: Key -> ([FilePath] -> [FilePath]) -> Annex [FilePath]
changeAssociatedFiles key transform = do
mapping <- calcRepo $ gitAnnexMapping key
files <- associatedFilesRelative key
let files' = transform files
when (files /= files') $ do
modifyContent mapping $
liftIO $ viaTmp writeFileAnyEncoding mapping $
unlines files'
top <- fromRepo Git.repoPath
return $ map (top </>) files'
{- Removes the list of associated files. -}
removeAssociatedFiles :: Key -> Annex ()
removeAssociatedFiles key = do
mapping <- calcRepo $ gitAnnexMapping key
modifyContent mapping $
liftIO $ nukeFile mapping
{- Removes an associated file. Returns new associatedFiles value.
- Checks if this was the last copy of the object, and updates location
- log. -}
removeAssociatedFile :: Key -> FilePath -> Annex [FilePath]
removeAssociatedFile key file = do
fs <- removeAssociatedFileUnchecked key file
when (null fs) $
logStatus key InfoMissing
return fs
{- Removes an associated file. Returns new associatedFiles value. -}
removeAssociatedFileUnchecked :: Key -> FilePath -> Annex [FilePath]
removeAssociatedFileUnchecked key file = do
file' <- normaliseAssociatedFile file
changeAssociatedFiles key $ filter (/= file')
{- Adds an associated file. Returns new associatedFiles value. -}
addAssociatedFile :: Key -> FilePath -> Annex [FilePath]
addAssociatedFile key file = do
file' <- normaliseAssociatedFile file
changeAssociatedFiles key $ \files ->
if file' `elem` files
then files
else file':files
{- Associated files are always stored relative to the top of the repository.
- The input FilePath is relative to the CWD, or is absolute. -}
normaliseAssociatedFile :: FilePath -> Annex FilePath
normaliseAssociatedFile file = do
top <- fromRepo Git.repoPath
liftIO $ relPathDirToFile top <$> absPath file
{- Checks if a file in the tree, associated with a key, has not been modified.
-
- To avoid needing to fsck the file's content, which can involve an
- expensive checksum, this relies on a cache that contains the file's
- expected mtime and inode.
-}
goodContent :: Key -> FilePath -> Annex Bool
goodContent key file = sameInodeCache file =<< recordedInodeCache key
{- Gets the recorded inode cache for a key.
-
- A key can be associated with multiple files, so may return more than
- one. -}
recordedInodeCache :: Key -> Annex [InodeCache]
recordedInodeCache key = withInodeCacheFile key $ \f ->
liftIO $ catchDefaultIO [] $
mapMaybe readInodeCache . lines <$> readFileStrict f
{- Caches an inode for a file.
-
- Anything else already cached is preserved.
-}
updateInodeCache :: Key -> FilePath -> Annex ()
updateInodeCache key file = maybe noop (addInodeCache key)
=<< liftIO (genInodeCache file)
{- Adds another inode to the cache for a key. -}
addInodeCache :: Key -> InodeCache -> Annex ()
addInodeCache key cache = do
oldcaches <- recordedInodeCache key
unlessM (elemInodeCaches cache oldcaches) $
writeInodeCache key (cache:oldcaches)
{- Writes inode cache for a key. -}
writeInodeCache :: Key -> [InodeCache] -> Annex ()
writeInodeCache key caches = withInodeCacheFile key $ \f ->
modifyContent f $
liftIO $ writeFile f $
unlines $ map showInodeCache caches
{- Removes an inode cache. -}
removeInodeCache :: Key -> Annex ()
removeInodeCache key = withInodeCacheFile key $ \f ->
modifyContent f $
liftIO $ nukeFile f
withInodeCacheFile :: Key -> (FilePath -> Annex a) -> Annex a
withInodeCacheFile key a = a =<< calcRepo (gitAnnexInodeCache key)
{- Checks if a InodeCache matches the current version of a file. -}
sameInodeCache :: FilePath -> [InodeCache] -> Annex Bool
sameInodeCache _ [] = return False
sameInodeCache file old = go =<< liftIO (genInodeCache file)
where
go Nothing = return False
go (Just curr) = elemInodeCaches curr old
{- Checks if a FileStatus matches the recorded InodeCache of a file. -}
sameFileStatus :: Key -> FileStatus -> Annex Bool
sameFileStatus key status = do
old <- recordedInodeCache key
let curr = toInodeCache status
case (old, curr) of
(_, Just c) -> elemInodeCaches c old
([], Nothing) -> return True
_ -> return False
{- If the inodes have changed, only the size and mtime are compared. -}
compareInodeCaches :: InodeCache -> InodeCache -> Annex Bool
compareInodeCaches x y
| compareStrong x y = return True
| otherwise = ifM inodesChanged
( return $ compareWeak x y
, return False
)
elemInodeCaches :: InodeCache -> [InodeCache] -> Annex Bool
elemInodeCaches _ [] = return False
elemInodeCaches c (l:ls) = ifM (compareInodeCaches c l)
( return True
, elemInodeCaches c ls
)
compareInodeCachesWith :: Annex InodeComparisonType
compareInodeCachesWith = ifM inodesChanged ( return Weakly, return Strongly )
{- Copies the contentfile to the associated file, if the associated
- file has no content. If the associated file does have content,
- even if the content differs, it's left unchanged. -}
addContentWhenNotPresent :: Key -> FilePath -> FilePath -> Annex ()
addContentWhenNotPresent key contentfile associatedfile = do
v <- isAnnexLink associatedfile
when (Just key == v) $
replaceFile associatedfile $
liftIO . void . copyFileExternal contentfile
updateInodeCache key associatedfile
{- Some filesystems get new inodes each time they are mounted.
- In order to work on such a filesystem, a sentinal file is used to detect
- when the inodes have changed.
-
- If the sentinal file does not exist, we have to assume that the
- inodes have changed.
-}
inodesChanged :: Annex Bool
inodesChanged = maybe calc return =<< Annex.getState Annex.inodeschanged
where
calc = do
scache <- liftIO . genInodeCache
=<< fromRepo gitAnnexInodeSentinal
scached <- readInodeSentinalFile
let changed = case (scache, scached) of
(Just c1, Just c2) -> not $ compareStrong c1 c2
_ -> True
Annex.changeState $ \s -> s { Annex.inodeschanged = Just changed }
return changed
readInodeSentinalFile :: Annex (Maybe InodeCache)
readInodeSentinalFile = do
sentinalcachefile <- fromRepo gitAnnexInodeSentinalCache
liftIO $ catchDefaultIO Nothing $
readInodeCache <$> readFile sentinalcachefile
writeInodeSentinalFile :: Annex ()
writeInodeSentinalFile = do
sentinalfile <- fromRepo gitAnnexInodeSentinal
createAnnexDirectory (parentDir sentinalfile)
sentinalcachefile <- fromRepo gitAnnexInodeSentinalCache
liftIO $ writeFile sentinalfile ""
liftIO $ maybe noop (writeFile sentinalcachefile . showInodeCache)
=<< genInodeCache sentinalfile
{- The sentinal file is only created when first initializing a repository.
- If there are any annexed objects in the repository already, creating
- the file would invalidate their inode caches. -}
createInodeSentinalFile :: Annex ()
createInodeSentinalFile =
unlessM (alreadyexists <||> hasobjects)
writeInodeSentinalFile
where
alreadyexists = isJust <$> readInodeSentinalFile
hasobjects = liftIO . doesDirectoryExist =<< fromRepo gitAnnexObjectDir