git-annex/CmdLine/Batch.hs
Joey Hess 12460fcea6
make --batch honor matching options
When --batch is used with matching options like --in, --metadata, etc, only
operate on the provided files when they match those options. Otherwise, a
blank line is output in the batch protocol.

Affected commands: find, add, whereis, drop, copy, move, get

In the case of find, the documentation for --batch already said it honored
the matching options. The docs for the rest didn't, but it makes sense to
have them honor them. While this is a behavior change, why specify the
matching options with --batch if you didn't want them to apply?

Note that the batch output for all of the affected commands could
already output a blank line in other cases, so batch users should
already be prepared to deal with it.

git-annex metadata didn't seem worth making support the matching options,
since all it does is output metadata or set metadata, the use cases for
using it in combination with the martching options seem small. Made it
refuse to run when they're combined, leaving open the possibility for later
support if a use case develops.

This commit was sponsored by Brett Eisenberg on Patreon.
2018-08-08 12:07:06 -04:00

91 lines
2.8 KiB
Haskell

{- git-annex batch commands
-
- Copyright 2015 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module CmdLine.Batch where
import Annex.Common
import Types.Command
import CmdLine.Action
import CmdLine.GitAnnex.Options
import Options.Applicative
import Limit
import Types.FileMatcher
data BatchMode = Batch | NoBatch
parseBatchOption :: Parser BatchMode
parseBatchOption = flag NoBatch Batch
( long "batch"
<> help "enable batch mode"
)
-- A batchable command can run in batch mode, or not.
-- In batch mode, one line at a time is read, parsed, and a reply output to
-- stdout. In non batch mode, the command's parameters are parsed and
-- a reply output for each.
batchable :: (opts -> String -> Annex Bool) -> Parser opts -> CmdParamsDesc -> CommandParser
batchable handler parser paramdesc = batchseeker <$> batchparser
where
batchparser = (,,)
<$> parser
<*> parseBatchOption
<*> cmdParams paramdesc
batchseeker (opts, NoBatch, params) = mapM_ (go NoBatch opts) params
batchseeker (opts, Batch, _) = batchInput Right (go Batch opts)
go batchmode opts p =
unlessM (handler opts p) $
batchBadInput batchmode
-- bad input is indicated by an empty line in batch mode. In non batch
-- mode, exit on bad input.
batchBadInput :: BatchMode -> Annex ()
batchBadInput NoBatch = liftIO exitFailure
batchBadInput Batch = liftIO $ putStrLn ""
-- Reads lines of batch mode input and passes to the action to handle.
batchInput :: (String -> Either String a) -> (a -> Annex ()) -> Annex ()
batchInput parser a = go =<< batchLines
where
go [] = return ()
go (l:rest) = do
either parseerr a (parser l)
go rest
parseerr s = giveup $ "Batch input parse failure: " ++ s
batchLines :: Annex [String]
batchLines = liftIO $ lines <$> getContents
-- Runs a CommandStart in batch mode.
--
-- The batch mode user expects to read a line of output, and it's up to the
-- CommandStart to generate that output as it succeeds or fails to do its
-- job. However, if it stops without doing anything, it won't generate
-- any output, so in that case, batchBadInput is used to provide the caller
-- with an empty line.
batchCommandAction :: CommandStart -> Annex ()
batchCommandAction a = maybe (batchBadInput Batch) (const noop)
=<< callCommandAction' a
-- Reads lines of batch input and passes the filepaths to a CommandStart
-- to handle them.
--
-- File matching options are not checked.
allBatchFiles :: (FilePath -> CommandStart) -> Annex ()
allBatchFiles a = batchInput Right $ batchCommandAction . a
-- Like allBatchFiles, but checks the file matching options
-- and skips non-matching files.
batchFilesMatching :: (FilePath -> CommandStart) -> Annex ()
batchFilesMatching a = do
matcher <- getMatcher
allBatchFiles $ \f ->
ifM (matcher $ MatchingFile $ FileInfo f f)
( a f
, return Nothing
)