git-annex/Annex/Drop.hs
Joey Hess 3a05d53761
add SeekInput (not yet used)
No behavior changes (hopefully), just adding SeekInput and plumbing it
through to the JSON display code for later use.

Over the course of 2 grueling days.

withFilesNotInGit reimplemented in terms of seekHelper
should be the only possible behavior change. It seems to test as
behaving the same.

Note that seekHelper dummies up the SeekInput in the case where
segmentPaths' gives up on sorting the expanded paths because there are
too many input paths. When SeekInput later gets exposed as a json field,
that will result in it being a little bit wrong in the case where
100 or more paths are passed to a git-annex command. I think this is a
subtle enough problem to not matter. If it does turn out to be a
problem, fixing it would require splitting up the input
parameters into groups of < 100, which would make git ls-files run
perhaps more than is necessary. May want to revisit this, because that
fix seems fairly low-impact.
2020-09-15 15:41:13 -04:00

133 lines
4.3 KiB
Haskell

{- dropping of unwanted content
-
- Copyright 2012-2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL 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.Content
import Annex.SpecialRemote.Config
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.
-
- The runner is used to run CommandStart sequentially, it's typically
- callCommandAction.
-}
handleDropsFrom :: [UUID] -> [Remote] -> Reason -> Bool -> Key -> AssociatedFile -> SeekInput -> [VerifiedCopy] -> (CommandStart -> CommandCleanup) -> Annex ()
handleDropsFrom locs rs reason fromhere key afile si preverified runner = do
g <- Annex.gitRepo
l <- 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 . fromRawFilePath) 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 -> serializeKey key
AssociatedFile (Just af) -> fromRawFilePath 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 ->
stopUnless (inAnnex key) $
Command.Drop.startLocal afile ai si numcopies key preverified
dropr fs r n = checkdrop fs n (Just $ Remote.uuid r) $ \numcopies ->
Command.Drop.startRemote afile ai si numcopies key r
ai = mkActionItem (key, afile)
slocs = S.fromList locs
safely a = either (const False) id <$> tryNonAsync a