git-annex/Command/DropKey.hs
Joey Hess 436f107715
make CommandStart return a StartMessage
The goal is to be able to run CommandStart in the main thread when -J is
used, rather than unncessarily passing it off to a worker thread, which
incurs overhead that is signficant when the CommandStart is going to
quickly decide to stop.

To do that, the message it displays needs to be displayed in the worker
thread, after the CommandStart has run.

Also, the change will mean that CommandStart will no longer necessarily
run with the same Annex state as CommandPerform. While its docs already
said it should avoid modifying Annex state, I audited all the
CommandStart code as part of the conversion. (Note that CommandSeek
already sometimes runs with a different Annex state, and that has not been
a source of any problems, so I am not too worried that this change will
lead to breakage going forward.)

The only modification of Annex state I found was it calling
allowMessages in some Commands that default to noMessages. Dealt with
that by adding a startCustomOutput and a startingUsualMessages.
This lets a command start with noMessages and then select the output it
wants for each CommandStart.

One bit of breakage: onlyActionOn has been removed from commands that used it.
The plan is that, since a StartMessage contains an ActionItem,
when a Key can be extracted from that, the parallel job runner can
run onlyActionOn' automatically. Then commands won't need to worry about
this detail. Future work.

Otherwise, this was a fairly straightforward process of making each
CommandStart compile again. Hopefully other behavior changes were mostly
avoided.

In a few cases, a command had a CommandStart that called a CommandPerform
that then called showStart multiple times. I have collapsed those
down to a single start action. The main command to perhaps suffer from it
is Command.Direct, which used to show a start for each file, and no
longer does.

Another minor behavior change is that some commands used showStart
before, but had an associated file and a Key available, so were changed
to ShowStart with an ActionItemAssociatedFile. That will not change the
normal output or behavior, but --json output will now include the key.
This should not break it for anyone using a real json parser.
2019-06-06 17:13:54 -04:00

58 lines
1.4 KiB
Haskell

{- git-annex command
-
- Copyright 2010,2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Command.DropKey where
import Command
import qualified Annex
import Logs.Location
import Annex.Content
cmd :: Command
cmd = noCommit $ withGlobalOptions [jsonOptions] $
command "dropkey" SectionPlumbing
"drops annexed content for specified keys"
(paramRepeating paramKey)
(seek <$$> optParser)
data DropKeyOptions = DropKeyOptions
{ toDrop :: [String]
, batchOption :: BatchMode
}
optParser :: CmdParamsDesc -> Parser DropKeyOptions
optParser desc = DropKeyOptions
<$> cmdParams desc
<*> parseBatchOption
seek :: DropKeyOptions -> CommandSeek
seek o = do
unlessM (Annex.getState Annex.force) $
giveup "dropkey can cause data loss; use --force if you're sure you want to do this"
withKeys (commandAction . start) (toDrop o)
case batchOption o of
Batch fmt -> batchInput fmt parsekey $ batchCommandAction . start
NoBatch -> noop
where
parsekey = maybe (Left "bad key") Right . deserializeKey
start :: Key -> CommandStart
start key = starting "dropkey" (mkActionItem key) $
perform key
perform :: Key -> CommandPerform
perform key = ifM (inAnnex key)
( lockContentForRemoval key $ \contentlock -> do
removeAnnex contentlock
next $ cleanup key
, next $ return True
)
cleanup :: Key -> CommandCleanup
cleanup key = do
logStatus key InfoMissing
return True