git-annex/Annex/Drop.hs
Joey Hess 6d381df0e6
sync --content: Fix dropping unwanted content from the local repository
This fixes a bug with the numcopies counting when using sync --content.
It did not always pass the local repo uuid to handleDropsFrom, and so the
numcopies counting was off by one, and unwanted local content would only be
dropped when there were numcopies+1 remote copies.

Also, support dropping local content that has reached an
exporttree remote that is not untrusted (currently only S3 remotes
with versioning).
2018-12-18 13:58:12 -04:00

137 lines
4.4 KiB
Haskell

{- dropping of unwanted content
-
- Copyright 2012-2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Drop where
import Annex.Common
import qualified Annex
import Logs.Trust
import Annex.NumCopies
import Types.Remote (uuid, appendonly, config)
import qualified Remote
import qualified Command.Drop
import Command
import Annex.Wanted
import Annex.Export
import Config
import Annex.Content.Direct
import qualified Database.Keys
import Git.FilePath
import qualified Data.Set as S
import System.Log.Logger (debugM)
type Reason = String
{- Drop a key from local and/or remote when allowed by the preferred content
- and numcopies settings.
-
- Skips trying to drop from remotes that are appendonly, since those drops
- would presumably fail. Also skips dropping from exporttree remotes,
- which don't allow dropping individual keys.
-
- 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 allowed to drop fromhere, that drop will be done last. This is done
- because local drops do not need any LockedCopy evidence, and so dropping
- from local last allows the content to be removed from more remotes.
-
- A VerifiedCopy can be provided as an optimisation when eg, a key
- has just been uploaded to a remote.
-
- In direct mode, all associated files are checked, and only if all
- of them are unwanted are they dropped.
-
- The runner is used to run commands, and so can be either callCommand
- or commandAction.
-}
handleDropsFrom :: [UUID] -> [Remote] -> Reason -> Bool -> Key -> AssociatedFile -> [VerifiedCopy] -> (CommandStart -> CommandCleanup) -> Annex ()
handleDropsFrom locs rs reason fromhere key afile preverified runner = do
l <- ifM isDirect
( associatedFilesRelative key
, do
g <- Annex.gitRepo
map (`fromTopFilePath` g) <$> Database.Keys.getAssociatedFiles key
)
let fs = case afile of
AssociatedFile (Just f) -> nub (f : l)
AssociatedFile Nothing -> l
n <- getcopies fs
void $ if fromhere && checkcopies n Nothing
then go fs rs n >>= dropl fs
else go fs rs n
where
getcopies fs = do
(untrusted, have) <- trustPartition UnTrusted locs
numcopies <- if null fs
then getNumCopies
else maximum <$> mapM getFileNumCopies fs
return (NumCopies (length have), numcopies, S.fromList untrusted)
{- Check that we have enough copies still to drop the content.
- When the remote being dropped from is untrusted, it was not
- counted as a copy, so having only numcopies suffices. Otherwise,
- we need more than numcopies to safely drop. -}
checkcopies (have, numcopies, _untrusted) Nothing = have > numcopies
checkcopies (have, numcopies, untrusted) (Just u)
| S.member u untrusted = have >= numcopies
| otherwise = have > numcopies
decrcopies (have, numcopies, untrusted) Nothing =
(NumCopies (fromNumCopies have - 1), numcopies, untrusted)
decrcopies v@(_have, _numcopies, untrusted) (Just u)
| S.member u untrusted = v
| otherwise = decrcopies v Nothing
go _ [] n = pure n
go fs (r:rest) n
| uuid r `S.notMember` slocs = go fs rest n
| appendonly r = go fs rest n
| exportTree (config r) = go fs rest n
| checkcopies n (Just $ Remote.uuid r) =
dropr fs r n >>= go fs rest
| otherwise = pure n
checkdrop fs n u a
| null fs = check $ -- no associated files; unused content
wantDrop True u (Just key) (AssociatedFile Nothing)
| otherwise = check $
allM (wantDrop True u (Just key) . AssociatedFile . Just) fs
where
check c = ifM c
( dodrop n u a
, return n
)
dodrop n@(have, numcopies, _untrusted) u a =
ifM (safely $ runner $ a numcopies)
( do
liftIO $ debugM "drop" $ unwords
[ "dropped"
, case afile of
AssociatedFile Nothing -> key2file key
AssociatedFile (Just af) -> af
, "(from " ++ maybe "here" show u ++ ")"
, "(copies now " ++ show (fromNumCopies have - 1) ++ ")"
, ": " ++ reason
]
return $ decrcopies n u
, return n
)
dropl fs n = checkdrop fs n Nothing $ \numcopies ->
Command.Drop.startLocal afile (mkActionItem afile) numcopies key preverified
dropr fs r n = checkdrop fs n (Just $ Remote.uuid r) $ \numcopies ->
Command.Drop.startRemote afile (mkActionItem afile) numcopies key r
slocs = S.fromList locs
safely a = either (const False) id <$> tryNonAsync a