git-annex/Command/Undo.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

76 lines
2.2 KiB
Haskell

{- git-annex command
-
- Copyright 2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Command.Undo where
import Command
import Git.DiffTree
import Git.FilePath
import Git.UpdateIndex
import Git.Sha
import qualified Git.LsFiles as LsFiles
import qualified Git.Command as Git
import qualified Git.Branch
import qualified Command.Sync
cmd :: Command
cmd = notBareRepo $
command "undo" SectionCommon
"undo last change to a file or directory"
paramPaths (withParams seek)
seek :: CmdParams -> CommandSeek
seek ps = do
-- Safety first; avoid any undo that would touch files that are not
-- in the index.
(fs, cleanup) <- inRepo $ LsFiles.notInRepo [] False (map toRawFilePath ps)
unless (null fs) $
giveup $ "Cannot undo changes to files that are not checked into git: " ++ unwords (map fromRawFilePath fs)
void $ liftIO $ cleanup
-- Committing staged changes before undo allows later
-- undoing the undo. It would be nicer to only commit staged
-- changes to the specified files, rather than all staged changes.
void $ Command.Sync.commitStaged Git.Branch.ManualCommit
"commit before undo"
withStrings (commandAction . start) ps
start :: FilePath -> CommandStart
start p = starting "undo" ai si $
perform p
where
ai = ActionItemOther (Just p)
si = SeekInput [p]
perform :: FilePath -> CommandPerform
perform p = do
g <- gitRepo
-- Get the reversed diff that needs to be applied to undo.
(diff, cleanup) <- inRepo $
diffLog [Param "-R", Param "--", Param p]
top <- inRepo $ toTopFilePath $ toRawFilePath p
let diff' = filter (`isDiffOf` top) diff
liftIO $ streamUpdateIndex g (map stageDiffTreeItem diff')
-- Take two passes through the diff, first doing any removals,
-- and then any adds. This order is necessary to handle eg, removing
-- a directory and replacing it with a file.
let (removals, adds) = partition (\di -> dstsha di `elem` nullShas) diff'
let mkrel di = liftIO $ relPathCwdToFile $ fromRawFilePath $
fromTopFilePath (file di) g
forM_ removals $ \di -> do
f <- mkrel di
liftIO $ nukeFile f
forM_ adds $ \di -> do
f <- mkrel di
inRepo $ Git.run [Param "checkout", Param "--", File f]
next $ liftIO cleanup