git-annex/Command/Unused.hs

211 lines
6.2 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_, when)
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 LocationLog
import qualified Annex
import qualified GitRepo as Git
import qualified Backend
import qualified Remote
command :: [Command]
command = [repoCommand "unused" paramNothing seek
"look for unused file content"]
seek :: [CommandSeek]
seek = [withNothing start]
{- Finds unused content in the annex. -}
start :: CommandStartNothing
start = notBareRepo $ do
from <- Annex.getState Annex.fromremote
let (name, action) = case from of
Nothing -> (".", checkUnused)
Just "." -> (".", checkUnused)
Just n -> (n, checkRemoteUnused n)
showStart "unused" name
next action
checkUnused :: CommandPerform
checkUnused = do
(unused, stalebad, staletmp) <- unusedKeys
_ <- list "" unusedMsg unused 0 >>=
list "bad" staleBadMsg stalebad >>=
list "tmp" staleTmpMsg staletmp
next $ return True
where
list file msg l c = do
let unusedlist = number c l
when (not $ null l) $ showLongNote $ msg unusedlist
writeUnusedFile file unusedlist
return $ c + length l
checkRemoteUnused :: String -> CommandPerform
checkRemoteUnused name = do
checkRemoteUnused' =<< Remote.byName name
next $ return True
checkRemoteUnused' :: Remote.Remote Annex -> Annex ()
checkRemoteUnused' r = do
showNote $ "checking for unused data..."
g <- Annex.gitRepo
referenced <- getKeysReferenced
logged <- liftIO $ loggedKeys g
remotehas <- filterM isthere logged
let remoteunused = remotehas `exclude` referenced
let list = number 0 remoteunused
writeUnusedFile "" list
unless (null remoteunused) $ do
showLongNote $ remoteUnusedMsg r list
showLongNote $ "\n"
where
isthere k = do
g <- Annex.gitRepo
us <- liftIO $ keyLocations g k
return $ uuid `elem` us
uuid = Remote.uuid r
writeUnusedFile :: FilePath -> [(Int, Key)] -> Annex ()
writeUnusedFile prefix l = do
g <- Annex.gitRepo
liftIO $ safeWriteFile (gitAnnexUnusedLog prefix g) $
unlines $ map (\(n, k) -> show n ++ " " ++ show k) l
table :: [(Int, Key)] -> [String]
table l = [" NUMBER KEY"] ++ map cols l
where
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)
staleTmpMsg :: [(Int, Key)] -> String
staleTmpMsg t = unlines $
["Some partially transferred data exists in temporary files:"]
++ table t ++ [dropMsg Nothing]
staleBadMsg :: [(Int, Key)] -> String
staleBadMsg t = unlines $
["Some corrupted files have been preserved by fsck, just in case:"]
++ table t ++ [dropMsg Nothing]
unusedMsg :: [(Int, Key)] -> String
unusedMsg u = unusedMsg' u
["Some annexed data is no longer used by any files in the repository:"]
[dropMsg Nothing]
remoteUnusedMsg :: Remote.Remote Annex -> [(Int, Key)] -> String
remoteUnusedMsg r u = unusedMsg' u
["Some annexed data on " ++ name ++
" is not used by any files in this repository."]
[dropMsg $ Just r,
"Please be cautious -- are you sure that the remote repository",
"does not use this data?"]
where
name = Remote.name r
unusedMsg' :: [(Int, Key)] -> [String] -> [String] -> String
unusedMsg' u header trailer = unlines $
header ++
table u ++
["(To see where data was previously used, try: git log --stat -S'KEY')"] ++
trailer
dropMsg :: Maybe (Remote.Remote Annex) -> String
dropMsg Nothing = dropMsg' ""
dropMsg (Just r) = dropMsg' $ " --from " ++ Remote.name r
dropMsg' :: String -> String
dropMsg' s = "(To remove unwanted data: git-annex dropunused" ++ s ++ " NUMBER)\n"
{- 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 bad or tmp
- files. -}
unusedKeys :: Annex ([Key], [Key], [Key])
unusedKeys = do
fast <- Annex.getState Annex.fast
if fast
then do
showNote "fast mode enabled; only finding stale files"
tmp <- staleKeys gitAnnexTmpDir
bad <- staleKeys gitAnnexBadDir
return ([], bad, tmp)
else do
showNote "checking for unused data..."
present <- getKeysPresent
referenced <- getKeysReferenced
let unused = present `exclude` referenced
staletmp <- staleKeysPrune gitAnnexTmpDir present
stalebad <- staleKeysPrune gitAnnexBadDir present
return (unused, stalebad, staletmp)
{- Finds items in the first, smaller list, that are not
- present in the second, larger list.
-
- 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 :: Ord a => [a] -> [a] -> [a]
exclude [] _ = [] -- optimisation
exclude smaller larger = S.toList $ remove larger $ S.fromList smaller
where
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
{- Looks in the specified directory for bad/tmp keys, and returns a list
- of those that might still have value, or might be stale and removable.
-
- When a list of presently available keys is provided, stale keys
- that no longer have value are deleted.
-}
staleKeysPrune :: (Git.Repo -> FilePath) -> [Key] -> Annex [Key]
staleKeysPrune dirspec present = do
contents <- staleKeys dirspec
let stale = contents `exclude` present
let dup = contents `exclude` stale
g <- Annex.gitRepo
let dir = dirspec g
liftIO $ forM_ dup $ \t -> removeFile $ dir </> keyFile t
return stale
staleKeys :: (Git.Repo -> FilePath) -> Annex [Key]
staleKeys dirspec = do
g <- Annex.gitRepo
let dir = dirspec g
exists <- liftIO $ doesDirectoryExist dir
if not exists
then return []
else do
contents <- liftIO $ getDirectoryContents dir
files <- liftIO $ filterM doesFileExist $
map (dir </>) contents
return $ catMaybes $ map (fileKey . takeFileName) files