191 lines
6.2 KiB
Haskell
191 lines
6.2 KiB
Haskell
{- git-annex file locations
|
|
-
|
|
- Copyright 2010 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Locations (
|
|
gitStateDir,
|
|
stateDir,
|
|
keyFile,
|
|
fileKey,
|
|
gitAnnexLocation,
|
|
annexLocation,
|
|
gitAnnexDir,
|
|
gitAnnexObjectDir,
|
|
gitAnnexTmpDir,
|
|
gitAnnexTmpLocation,
|
|
gitAnnexBadDir,
|
|
gitAnnexBadLocation,
|
|
gitAnnexUnusedLog,
|
|
isLinkToAnnex,
|
|
logFile,
|
|
logFileKey,
|
|
hashDirMixed,
|
|
hashDirLower,
|
|
|
|
prop_idempotent_fileKey
|
|
) where
|
|
|
|
import System.FilePath
|
|
import Data.String.Utils
|
|
import Data.List
|
|
import Bits
|
|
import Word
|
|
import Data.Hash.MD5
|
|
|
|
import Types
|
|
import Types.Key
|
|
import qualified GitRepo as Git
|
|
|
|
{- Conventions:
|
|
-
|
|
- Functions ending in "Dir" should always return values ending with a
|
|
- trailing path separator. Most code does not rely on that, but a few
|
|
- things do.
|
|
-
|
|
- Everything else should not end in a trailing path sepatator.
|
|
-
|
|
- Only functions (with names starting with "git") that build a path
|
|
- based on a git repository should return an absolute path.
|
|
- Everything else should use relative paths.
|
|
-}
|
|
|
|
{- Long-term, cross-repo state is stored in files inside the .git-annex
|
|
- directory, in the git repository's working tree. -}
|
|
stateDir :: FilePath
|
|
stateDir = addTrailingPathSeparator $ ".git-annex"
|
|
gitStateDir :: Git.Repo -> FilePath
|
|
gitStateDir repo = addTrailingPathSeparator $ Git.workTree repo </> stateDir
|
|
|
|
{- The directory git annex uses for local state, relative to the .git
|
|
- directory -}
|
|
annexDir :: FilePath
|
|
annexDir = addTrailingPathSeparator $ "annex"
|
|
|
|
{- The directory git annex uses for locally available object content,
|
|
- relative to the .git directory -}
|
|
objectDir :: FilePath
|
|
objectDir = addTrailingPathSeparator $ annexDir </> "objects"
|
|
|
|
{- Annexed file's location relative to the .git directory. -}
|
|
annexLocation :: Key -> FilePath
|
|
annexLocation key = objectDir </> hashDirMixed key </> f </> f
|
|
where
|
|
f = keyFile key
|
|
|
|
{- Annexed file's absolute location in a repository. -}
|
|
gitAnnexLocation :: Git.Repo -> Key -> FilePath
|
|
gitAnnexLocation r key
|
|
| Git.repoIsLocalBare r = Git.workTree r </> annexLocation key
|
|
| otherwise = Git.workTree r </> ".git" </> annexLocation key
|
|
|
|
{- The annex directory of a repository. -}
|
|
gitAnnexDir :: Git.Repo -> FilePath
|
|
gitAnnexDir r
|
|
| Git.repoIsLocalBare r = addTrailingPathSeparator $ Git.workTree r </> annexDir
|
|
| otherwise = addTrailingPathSeparator $ Git.workTree r </> ".git" </> annexDir
|
|
|
|
{- The part of the annex directory where file contents are stored.
|
|
-}
|
|
gitAnnexObjectDir :: Git.Repo -> FilePath
|
|
gitAnnexObjectDir r
|
|
| Git.repoIsLocalBare r = addTrailingPathSeparator $ Git.workTree r </> objectDir
|
|
| otherwise = addTrailingPathSeparator $ Git.workTree r </> ".git" </> objectDir
|
|
|
|
{- .git/annex/tmp/ is used for temp files -}
|
|
gitAnnexTmpDir :: Git.Repo -> FilePath
|
|
gitAnnexTmpDir r = addTrailingPathSeparator $ gitAnnexDir r </> "tmp"
|
|
|
|
{- The temp file to use for a given key. -}
|
|
gitAnnexTmpLocation :: Git.Repo -> Key -> FilePath
|
|
gitAnnexTmpLocation r key = gitAnnexTmpDir r </> keyFile key
|
|
|
|
{- .git/annex/bad/ is used for bad files found during fsck -}
|
|
gitAnnexBadDir :: Git.Repo -> FilePath
|
|
gitAnnexBadDir r = addTrailingPathSeparator $ gitAnnexDir r </> "bad"
|
|
|
|
{- The bad file to use for a given key. -}
|
|
gitAnnexBadLocation :: Git.Repo -> Key -> FilePath
|
|
gitAnnexBadLocation r key = gitAnnexBadDir r </> keyFile key
|
|
|
|
{- .git/annex/*unused is used to number possibly unused keys -}
|
|
gitAnnexUnusedLog :: FilePath -> Git.Repo -> FilePath
|
|
gitAnnexUnusedLog prefix r = gitAnnexDir r </> (prefix ++ "unused")
|
|
|
|
{- Checks a symlink target to see if it appears to point to annexed content. -}
|
|
isLinkToAnnex :: FilePath -> Bool
|
|
isLinkToAnnex s = ("/.git/" ++ objectDir) `isInfixOf` s
|
|
|
|
{- The filename of the log file for a given key. -}
|
|
logFile :: Key -> String
|
|
logFile key = hashDirLower key ++ keyFile key ++ ".log"
|
|
|
|
{- Converts a log filename into a key. -}
|
|
logFileKey :: FilePath -> Maybe Key
|
|
logFileKey file
|
|
| end == ".log" = readKey beginning
|
|
| otherwise = Nothing
|
|
where
|
|
(beginning, end) = splitAt (length file - 4) file
|
|
|
|
{- Converts a key into a filename fragment.
|
|
-
|
|
- Escape "/" in the key name, to keep a flat tree of files and avoid
|
|
- issues with keys containing "/../" or ending with "/" etc.
|
|
-
|
|
- "/" is escaped to "%" because it's short and rarely used, and resembles
|
|
- a slash
|
|
- "%" is escaped to "&s", and "&" to "&a"; this ensures that the mapping
|
|
- is one to one.
|
|
- ":" is escaped to "&c", because despite it being 2011, people still care
|
|
- about FAT.
|
|
- -}
|
|
keyFile :: Key -> FilePath
|
|
keyFile key = replace "/" "%" $ replace ":" "&c" $
|
|
replace "%" "&s" $ replace "&" "&a" $ show key
|
|
|
|
{- Reverses keyFile, converting a filename fragment (ie, the basename of
|
|
- the symlink target) into a key. -}
|
|
fileKey :: FilePath -> Maybe Key
|
|
fileKey file = readKey $
|
|
replace "&a" "&" $ replace "&s" "%" $
|
|
replace "&c" ":" $ replace "%" "/" file
|
|
|
|
{- for quickcheck -}
|
|
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
|
|
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 k = addTrailingPathSeparator $ take 3 dir </> drop 3 dir
|
|
where
|
|
dir = take 6 $ md5s $ Str $ show k
|
|
|
|
{- modified version of display_32bits_as_hex from Data.Hash.MD5
|
|
- Copyright (C) 2001 Ian Lynagh
|
|
- License: Either BSD or GPL
|
|
-}
|
|
display_32bits_as_dir :: Word32 -> String
|
|
display_32bits_as_dir w = trim $ swap_pairs cs
|
|
where
|
|
-- Need 32 characters to use. To avoid inaverdently making
|
|
-- a real word, use letters that appear less frequently.
|
|
chars = ['0'..'9'] ++ "zqjxkmvwgpfZQJXKMVWGPF"
|
|
cs = map (\x -> getc $ (shiftR w (6*x)) .&. 31) [0..7]
|
|
getc n = chars !! (fromIntegral n)
|
|
swap_pairs (x1:x2:xs) = x2:x1:swap_pairs xs
|
|
swap_pairs _ = []
|
|
-- Last 2 will always be 00, so omit.
|
|
trim s = take 6 s
|