git-annex/Command/Unused.hs
2011-01-31 23:27:53 -04:00

129 lines
3.8 KiB
Haskell

{- git-annex command
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Unused where
import Control.Monad (filterM, unless, forM_)
import Control.Monad.State (liftIO)
import qualified Data.Set as S
import Data.Maybe
import System.FilePath
import System.Directory
import Command
import Types
import Content
import Messages
import Locations
import Utility
import qualified Annex
import qualified GitRepo as Git
import qualified Backend
command :: [Command]
command = [Command "unused" paramNothing seek "look for unused file content"]
seek :: [CommandSeek]
seek = [withNothing start]
{- Finds unused content in the annex. -}
start :: CommandStartNothing
start = do
showStart "unused" ""
return $ Just perform
perform :: CommandPerform
perform = do
_ <- checkUnused
return $ Just $ return True
checkUnused :: Annex Bool
checkUnused = do
showNote "checking for unused data..."
(unused, staletmp) <- unusedKeys
let unusedlist = number 0 unused
let staletmplist = number (length unused) staletmp
let list = unusedlist ++ staletmplist
g <- Annex.gitRepo
liftIO $ safeWriteFile (gitAnnexUnusedLog g) $ unlines $
map (\(n, k) -> show n ++ " " ++ show k) list
unless (null unused) $ showLongNote $ unusedmsg unusedlist
unless (null staletmp) $ showLongNote $ staletmpmsg staletmplist
unless (null list) $ showLongNote $ "\n"
return $ null list
where
unusedmsg u = unlines $
["Some annexed data is no longer pointed to by any files in the repository:"]
++ table u ++
["(To see where data was previously used, try: git log --stat -S'KEY')"] ++
dropmsg
staletmpmsg t = unlines $
["Some partially transferred data exists in temporary files:"]
++ table t ++ dropmsg
dropmsg = ["(To remove unwanted data: git-annex dropunused NUMBER)"]
table l = [" NUMBER KEY"] ++ map cols l
cols (n,k) = " " ++ pad 6 (show n) ++ " " ++ show k
pad n s = s ++ replicate (n - length s) ' '
number :: Int -> [a] -> [(Int, a)]
number _ [] = []
number n (x:xs) = (n+1, x):(number (n+1) xs)
{- Finds keys whose content is present, but that do not seem to be used
- by any files in the git repo, or that are only present as tmp files. -}
unusedKeys :: Annex ([Key], [Key])
unusedKeys = do
g <- Annex.gitRepo
present <- getKeysPresent
referenced <- getKeysReferenced
tmps <- tmpKeys
let (unused, staletmp, duptmp) = calcUnusedKeys present referenced tmps
-- Tmp files that are dups of content already present can simply
-- be removed.
liftIO $ forM_ duptmp $ \t -> removeFile $ gitAnnexTmpLocation g t
return (unused, staletmp)
calcUnusedKeys :: [Key] -> [Key] -> [Key] -> ([Key], [Key], [Key])
calcUnusedKeys present referenced tmps = (unused, staletmp, duptmp)
where
unused = present `exclude` referenced
staletmp = tmps `exclude` present
duptmp = tmps `exclude` staletmp
-- Constructing a single set, of the list that tends to be
-- smaller, appears more efficient in both memory and CPU
-- than constructing and taking the S.difference of two sets.
exclude [] _ = [] -- optimisation
exclude smaller larger = S.toList $ remove larger $ S.fromList smaller
remove a b = foldl (flip S.delete) b a
{- List of keys referenced by symlinks in the git repo. -}
getKeysReferenced :: Annex [Key]
getKeysReferenced = do
g <- Annex.gitRepo
files <- liftIO $ Git.inRepo g [Git.workTree g]
keypairs <- mapM Backend.lookupFile files
return $ map fst $ catMaybes keypairs
{- List of keys that have temp files in the git repo. -}
tmpKeys :: Annex [Key]
tmpKeys = do
g <- Annex.gitRepo
let tmp = gitAnnexTmpDir g
exists <- liftIO $ doesDirectoryExist tmp
if (not exists)
then return []
else do
contents <- liftIO $ getDirectoryContents tmp
files <- liftIO $ filterM doesFileExist $
map (tmp </>) contents
return $ map (fileKey . takeFileName) files