git-annex/Limit.hs
Joey Hess ba6088b249 rename readMaybe to readish
a stricter (but also partial) readMaybe is getting added to base
2012-01-23 17:00:10 -04:00

102 lines
3.1 KiB
Haskell

{- user-specified limits on files to act on
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Limit where
import Text.Regex.PCRE.Light.Char8
import System.Path.WildMatch
import Common.Annex
import qualified Annex
import qualified Utility.Matcher
import qualified Remote
import qualified Backend
import Annex.Content
type Limit = Utility.Matcher.Token (FilePath -> Annex Bool)
{- Checks if there are user-specified limits. -}
limited :: Annex Bool
limited = (not . Utility.Matcher.matchesAny) <$> getMatcher'
{- Gets a matcher for the user-specified limits. The matcher is cached for
- speed; once it's obtained the user-specified limits can't change. -}
getMatcher :: Annex (FilePath -> Annex Bool)
getMatcher = Utility.Matcher.matchM <$> getMatcher'
getMatcher' :: Annex (Utility.Matcher.Matcher (FilePath -> Annex Bool))
getMatcher' = do
m <- Annex.getState Annex.limit
case m of
Right r -> return r
Left l -> do
let matcher = Utility.Matcher.generate (reverse l)
Annex.changeState $ \s -> s { Annex.limit = Right matcher }
return matcher
{- Adds something to the limit list, which is built up reversed. -}
add :: Limit -> Annex ()
add l = Annex.changeState $ \s -> s { Annex.limit = prepend $ Annex.limit s }
where
prepend (Left ls) = Left $ l:ls
prepend _ = error "internal"
{- Adds a new token. -}
addToken :: String -> Annex ()
addToken = add . Utility.Matcher.token
{- Adds a new limit. -}
addLimit :: (FilePath -> Annex Bool) -> Annex ()
addLimit = add . Utility.Matcher.Operation
{- Add a limit to skip files that do not match the glob. -}
addInclude :: String -> Annex ()
addInclude glob = addLimit $ return . matchglob glob
{- Add a limit to skip files that match the glob. -}
addExclude :: String -> Annex ()
addExclude glob = addLimit $ return . not . matchglob glob
matchglob :: String -> FilePath -> Bool
matchglob glob f = isJust $ match cregex f []
where
cregex = compile regex []
regex = '^':wildToRegex glob
{- Adds a limit to skip files not believed to be present
- in a specfied repository. -}
addIn :: String -> Annex ()
addIn name = addLimit $ check $ if name == "." then inAnnex else inremote
where
check a = Backend.lookupFile >=> handle a
handle _ Nothing = return False
handle a (Just (key, _)) = a key
inremote key = do
u <- Remote.nameToUUID name
us <- Remote.keyLocations key
return $ u `elem` us
{- Adds a limit to skip files not believed to have the specified number
- of copies. -}
addCopies :: String -> Annex ()
addCopies num =
case readish num :: Maybe Int of
Nothing -> error "bad number for --copies"
Just n -> addLimit $ check n
where
check n = Backend.lookupFile >=> handle n
handle _ Nothing = return False
handle n (Just (key, _)) = do
us <- Remote.keyLocations key
return $ length us >= n
{- Adds a limit to skip files not using a specified key-value backend. -}
addInBackend :: String -> Annex ()
addInBackend name = addLimit $ Backend.lookupFile >=> check
where
wanted = Backend.lookupBackendName name
check = return . maybe False ((==) wanted . snd)