git-annex/Command/Drop.hs
2011-12-31 04:11:58 -04:00

132 lines
4.4 KiB
Haskell

{- git-annex command
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Drop where
import Common.Annex
import Command
import qualified Remote
import qualified Annex
import Annex.UUID
import Logs.Location
import Logs.Trust
import Annex.Content
import Config
def :: [Command]
def = [dontCheck fromOpt $ command "drop" paramPaths seek
"indicate content of files not currently wanted"]
seek :: [CommandSeek]
seek = [withNumCopies $ \n -> whenAnnexed $ start n]
start :: Maybe Int -> FilePath -> (Key, Backend) -> CommandStart
start numcopies file (key, _) = autoCopies key (>) numcopies $ do
from <- Annex.getState Annex.fromremote
case from of
Nothing -> startLocal file numcopies key
Just name -> do
remote <- Remote.byName name
u <- getUUID
if Remote.uuid remote == u
then startLocal file numcopies key
else startRemote file numcopies key remote
startLocal :: FilePath -> Maybe Int -> Key -> CommandStart
startLocal file numcopies key = stopUnless (inAnnex key) $ do
showStart "drop" file
next $ performLocal key numcopies
startRemote :: FilePath -> Maybe Int -> Key -> Remote -> CommandStart
startRemote file numcopies key remote = do
showStart "drop" file
next $ performRemote key numcopies remote
performLocal :: Key -> Maybe Int -> CommandPerform
performLocal key numcopies = lockContent key $ do
(remotes, trusteduuids) <- Remote.keyPossibilitiesTrusted key
untrusteduuids <- trustGet UnTrusted
let tocheck = Remote.remotesWithoutUUID remotes (trusteduuids++untrusteduuids)
stopUnless (canDropKey key numcopies trusteduuids tocheck []) $ do
whenM (inAnnex key) $ removeAnnex key
next $ cleanupLocal key
performRemote :: Key -> Maybe Int -> Remote -> CommandPerform
performRemote key numcopies remote = lockContent key $ do
-- Filter the remote it's being dropped from out of the lists of
-- places assumed to have the key, and places to check.
-- When the local repo has the key, that's one additional copy.
(remotes, trusteduuids) <- Remote.keyPossibilitiesTrusted key
present <- inAnnex key
u <- getUUID
let have = filter (/= uuid) $
if present then u:trusteduuids else trusteduuids
untrusteduuids <- trustGet UnTrusted
let tocheck = filter (/= remote) $
Remote.remotesWithoutUUID remotes (have++untrusteduuids)
stopUnless (canDropKey key numcopies have tocheck [uuid]) $ do
ok <- Remote.removeKey remote key
next $ cleanupRemote key remote ok
where
uuid = Remote.uuid remote
cleanupLocal :: Key -> CommandCleanup
cleanupLocal key = do
logStatus key InfoMissing
return True
cleanupRemote :: Key -> Remote -> Bool -> CommandCleanup
cleanupRemote key remote ok = do
-- better safe than sorry: assume the remote dropped the key
-- even if it seemed to fail; the failure could have occurred
-- after it really dropped it
Remote.logStatus remote key False
return ok
{- Checks specified remotes to verify that enough copies of a key exist to
- allow it to be safely removed (with no data loss). Can be provided with
- some locations where the key is known/assumed to be present. -}
canDropKey :: Key -> Maybe Int -> [UUID] -> [Remote] -> [UUID] -> Annex Bool
canDropKey key numcopiesM have check skip = do
force <- Annex.getState Annex.force
if force || numcopiesM == Just 0
then return True
else do
need <- getNumCopies numcopiesM
findCopies key need skip have check
findCopies :: Key -> Int -> [UUID] -> [UUID] -> [Remote] -> Annex Bool
findCopies key need skip = helper []
where
helper bad have []
| length have >= need = return True
| otherwise = notEnoughCopies key need have skip bad
helper bad have (r:rs)
| length have >= need = return True
| otherwise = do
let u = Remote.uuid r
let duplicate = u `elem` have
haskey <- Remote.hasKey r key
case (duplicate, haskey) of
(False, Right True) -> helper bad (u:have) rs
(False, Left _) -> helper (r:bad) have rs
_ -> helper bad have rs
notEnoughCopies :: Key -> Int -> [UUID] -> [UUID] -> [Remote] -> Annex Bool
notEnoughCopies key need have skip bad = do
unsafe
showLongNote $
"Could only verify the existence of " ++
show (length have) ++ " out of " ++ show need ++
" necessary copies"
Remote.showTriedRemotes bad
Remote.showLocations key (have++skip)
hint
return False
where
unsafe = showNote "unsafe"
hint = showLongNote "(Use --force to override this check, or adjust annex.numcopies.)"