git-annex/Command/Find.hs
Joey Hess 34c8af74ba fix inversion of control in CommandSeek (no behavior changes)
I've been disliking how the command seek actions were written for some
time, with their inversion of control and ugly workarounds.

The last straw to fix it was sync --content, which didn't fit the
Annex [CommandStart] interface well at all. I have not yet made it take
advantage of the changed interface though.

The crucial change, and probably why I didn't do it this way from the
beginning, is to make each CommandStart action be run with exceptions
caught, and if it fails, increment a failure counter in annex state.
So I finally remove the very first code I wrote for git-annex, which
was before I had exception handling in the Annex monad, and so ran outside
that monad, passing state explicitly as it ran each CommandStart action.

This was a real slog from 1 to 5 am.

Test suite passes.

Memory usage is lower than before, sometimes by a couple of megabytes, and
remains constant, even when running in a large repo, and even when
repeatedly failing and incrementing the error counter. So no accidental
laziness space leaks.

Wall clock speed is identical, even in large repos.

This commit was sponsored by an anonymous bitcoiner.
2014-01-20 04:57:36 -04:00

74 lines
2.1 KiB
Haskell

{- git-annex command
-
- Copyright 2010-2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Find where
import qualified Data.Map as M
import Common.Annex
import Command
import Annex.Content
import Limit
import qualified Annex
import qualified Utility.Format
import Utility.DataUnits
import Types.Key
import qualified Option
import GitAnnex.Options
def :: [Command]
def = [noCommit $ noMessages $ withOptions [formatOption, print0Option, jsonOption] $
command "find" paramPaths seek SectionQuery "lists available files"]
formatOption :: Option
formatOption = Option.field [] "format" paramFormat "control format of output"
getFormat :: Annex (Maybe Utility.Format.Format)
getFormat = getOptionField formatOption $ return . fmap Utility.Format.gen
print0Option :: Option
print0Option = Option.Option [] ["print0"] (Option.NoArg set)
"terminate output with null"
where
set = Annex.setField (Option.name formatOption) "${file}\0"
seek :: CommandSeek
seek ps = do
format <- getFormat
withFilesInGit (whenAnnexed $ start format) ps
start :: Maybe Utility.Format.Format -> FilePath -> (Key, Backend) -> CommandStart
start format file (key, _) = do
-- only files inAnnex are shown, unless the user has requested
-- others via a limit
whenM (limited <||> inAnnex key) $
showFormatted format file $ ("file", file) : keyVars key
stop
showFormatted :: Maybe Utility.Format.Format -> String -> [(String, String)] -> Annex ()
showFormatted format unformatted vars =
unlessM (showFullJSON vars) $
case format of
Nothing -> liftIO $ putStrLn unformatted
Just formatter -> liftIO $ putStr $
Utility.Format.format formatter $
M.fromList vars
keyVars :: Key -> [(String, String)]
keyVars key =
[ ("key", key2file key)
, ("backend", keyBackendName key)
, ("bytesize", size show)
, ("humansize", size $ roughSize storageUnits True)
, ("keyname", keyName key)
, ("hashdirlower", hashDirLower key)
, ("hashdirmixed", hashDirMixed key)
, ("mtime", whenavail show $ keyMtime key)
]
where
size c = whenavail c $ keySize key
whenavail = maybe "unknown"