diff options
Diffstat (limited to 'Locations.hs')
| -rw-r--r-- | Locations.hs | 52 |
1 files changed, 32 insertions, 20 deletions
diff --git a/Locations.hs b/Locations.hs index 53a80043a..1b5f8108d 100644 --- a/Locations.hs +++ b/Locations.hs @@ -1,6 +1,6 @@ {- git-annex file locations - - - Copyright 2010 Joey Hess <joey@kitenet.net> + - Copyright 2010-2011 Joey Hess <joey@kitenet.net> - - Licensed under the GNU GPL version 3 or higher. -} @@ -8,6 +8,7 @@ module Locations ( keyFile, fileKey, + keyPaths, gitAnnexLocation, annexLocations, gitAnnexDir, @@ -59,22 +60,12 @@ annexDir = addTrailingPathSeparator "annex" objectDir :: FilePath objectDir = addTrailingPathSeparator $ annexDir </> "objects" -{- Two different directory hashes may be used. The mixed case hash - - came first, and is fine, except for the problem of case-strict - - filesystems such as Linux VFAT (mounted with shortname=mixed), - - which do not allow using a directory "XX" when "xx" already exists. - - To support that, some repositories will use a lower case hash. -} -annexHashes :: [Key -> FilePath] -annexHashes = [hashDirMixed, hashDirLower] - {- Annexed file's possible locations relative to the .git directory. - There are two different possibilities, using different hashes. -} annexLocations :: Key -> [FilePath] annexLocations key = map (annexLocation key) annexHashes -annexLocation :: Key -> (Key -> FilePath) -> FilePath -annexLocation key hasher = objectDir </> hasher key </> f </> f - where - f = keyFile key +annexLocation :: Key -> Hasher -> FilePath +annexLocation key hasher = objectDir </> keyPath key hasher {- Annexed file's absolute location in a repository. - @@ -150,7 +141,7 @@ gitAnnexJournalLock r = gitAnnexDir r </> "journal.lck" isLinkToAnnex :: FilePath -> Bool isLinkToAnnex s = ("/.git/" ++ objectDir) `isInfixOf` s -{- Converts a key into a filename fragment. +{- Converts a key into a filename fragment without any directory. - - Escape "/" in the key name, to keep a flat tree of files and avoid - issues with keys containing "/../" or ending with "/" etc. @@ -166,6 +157,22 @@ keyFile :: Key -> FilePath keyFile key = replace "/" "%" $ replace ":" "&c" $ replace "%" "&s" $ replace "&" "&a" $ show key +{- A location to store a key on the filesystem. A directory hash is used, + - to protect against filesystems that dislike having many items in a + - single directory. + - + - The file is put in a directory with the same name, this allows + - write-protecting the directory to avoid accidental deletion of the file. + -} +keyPath :: Key -> Hasher -> FilePath +keyPath key hasher = hasher key </> f </> f + where + f = keyFile key + +{- All possibile locations to store a key using different directory hashes. -} +keyPaths :: Key -> [FilePath] +keyPaths key = map (keyPath key) annexHashes + {- Reverses keyFile, converting a filename fragment (ie, the basename of - the symlink target) into a key. -} fileKey :: FilePath -> Maybe Key @@ -178,17 +185,22 @@ prop_idempotent_fileKey :: String -> Bool prop_idempotent_fileKey s = Just k == fileKey (keyFile k) where k = stubKey { keyName = s, keyBackendName = "test" } -{- Given a key, generates a short directory name to put it in, - - to do hashing to protect against filesystems that dislike having - - many items in a single directory. -} -hashDirMixed :: Key -> FilePath +{- Two different directory hashes may be used. The mixed case hash + - came first, and is fine, except for the problem of case-strict + - filesystems such as Linux VFAT (mounted with shortname=mixed), + - which do not allow using a directory "XX" when "xx" already exists. + - To support that, some repositories will use a lower case hash. -} +type Hasher = Key -> FilePath +annexHashes :: [Hasher] +annexHashes = [hashDirMixed, hashDirLower] + +hashDirMixed :: Hasher hashDirMixed k = addTrailingPathSeparator $ take 2 dir </> drop 2 dir where dir = take 4 $ display_32bits_as_dir =<< [a,b,c,d] ABCD (a,b,c,d) = md5 $ Str $ show k -{- Generates a hash directory that is all lower case. -} -hashDirLower :: Key -> FilePath +hashDirLower :: Hasher hashDirLower k = addTrailingPathSeparator $ take 3 dir </> drop 3 dir where dir = take 6 $ md5s $ Str $ show k |