git-annex/Assistant/Drop.hs
Joey Hess cc5db38a1e typo
2013-03-01 16:58:19 -04:00

87 lines
2.6 KiB
Haskell

{- git-annex assistant dropping of unwanted content
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Drop where
import Assistant.Common
import Assistant.DaemonStatus
import Logs.Location
import Logs.Trust
import Types.Remote (AssociatedFile, uuid)
import qualified Remote
import qualified Command.Drop
import Command
import Annex.Wanted
import Annex.Exception
import Config
import qualified Data.Set as S
type Reason = String
{- Drop from local and/or remote when allowed by the preferred content and
- numcopies settings. -}
handleDrops :: Reason -> Bool -> Key -> AssociatedFile -> Maybe Remote -> Assistant ()
handleDrops _ _ _ Nothing _ = noop
handleDrops reason fromhere key f knownpresentremote = do
syncrs <- syncDataRemotes <$> getDaemonStatus
locs <- liftAnnex $ loggedLocations key
handleDropsFrom locs syncrs reason fromhere key f knownpresentremote
{- The UUIDs are ones where the content is believed to be present.
- The Remote list can include other remotes that do not have the content;
- only ones that match the UUIDs will be dropped from.
- If allows to drop fromhere, that drop will be tried first. -}
handleDropsFrom :: [UUID] -> [Remote] -> Reason -> Bool -> Key -> AssociatedFile -> Maybe Remote -> Assistant ()
handleDropsFrom _ _ _ _ _ Nothing _ = noop
handleDropsFrom locs rs reason fromhere key (Just f) knownpresentremote
| fromhere = do
n <- getcopies
if checkcopies n
then go rs =<< dropl n
else go rs n
| otherwise = go rs =<< getcopies
where
getcopies = liftAnnex $ do
have <- length <$> trustExclude UnTrusted locs
numcopies <- getNumCopies =<< numCopies f
return (have, numcopies)
checkcopies (have, numcopies) = have > numcopies
decrcopies (have, numcopies) = (have - 1, numcopies)
go [] _ = noop
go (r:rest) n
| uuid r `S.notMember` slocs = go rest n
| checkcopies n = dropr r n >>= go rest
| otherwise = noop
checkdrop n@(have, numcopies) u a =
ifM (liftAnnex $ wantDrop True u (Just f))
( ifM (liftAnnex $ safely $ doCommand $ a (Just numcopies))
( do
debug
[ "dropped"
, f
, "(from " ++ maybe "here" show u ++ ")"
, "(copies now " ++ show (have - 1) ++ ")"
, ": " ++ reason
]
return $ decrcopies n
, return n
)
, return n
)
dropl n = checkdrop n Nothing $ \numcopies ->
Command.Drop.startLocal f numcopies key knownpresentremote
dropr r n = checkdrop n (Just $ Remote.uuid r) $ \numcopies ->
Command.Drop.startRemote f numcopies key r
safely a = either (const False) id <$> tryAnnex a
slocs = S.fromList locs