git-annex/Annex.hs
Joey Hess 30f1aeb13c golf
2011-11-12 14:24:07 -04:00

129 lines
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{- git-annex monad
-
- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
module Annex (
Annex,
AnnexState(..),
OutputType(..),
new,
newState,
run,
eval,
getState,
changeState,
gitRepo,
inRepo,
fromRepo,
) where
import Control.Monad.IO.Control
import Control.Monad.State
import Common
import qualified Git
import Git.CatFile
import Git.Queue
import Types.Backend
import qualified Types.Remote
import Types.Crypto
import Types.BranchState
import Types.TrustLevel
import Types.UUID
import qualified Utility.Matcher
-- git-annex's monad
newtype Annex a = Annex { runAnnex :: StateT AnnexState IO a }
deriving (
Monad,
MonadIO,
MonadControlIO,
MonadState AnnexState,
Functor,
Applicative
)
data OutputType = NormalOutput | QuietOutput | JSONOutput
-- internal state storage
data AnnexState = AnnexState
{ repo :: Git.Repo
, backends :: [Backend Annex]
, remotes :: [Types.Remote.Remote Annex]
, repoqueue :: Queue
, output :: OutputType
, force :: Bool
, fast :: Bool
, auto :: Bool
, branchstate :: BranchState
, catfilehandle :: Maybe CatFileHandle
, forcebackend :: Maybe String
, forcenumcopies :: Maybe Int
, toremote :: Maybe String
, fromremote :: Maybe String
, limit :: Either [Utility.Matcher.Token (FilePath -> Annex Bool)] (Utility.Matcher.Matcher (FilePath -> Annex Bool))
, forcetrust :: [(UUID, TrustLevel)]
, trustmap :: Maybe TrustMap
, cipher :: Maybe Cipher
}
newState :: Git.Repo -> AnnexState
newState gitrepo = AnnexState
{ repo = gitrepo
, backends = []
, remotes = []
, repoqueue = Git.Queue.empty
, output = NormalOutput
, force = False
, fast = False
, auto = False
, branchstate = startBranchState
, catfilehandle = Nothing
, forcebackend = Nothing
, forcenumcopies = Nothing
, toremote = Nothing
, fromremote = Nothing
, limit = Left []
, forcetrust = []
, trustmap = Nothing
, cipher = Nothing
}
{- Create and returns an Annex state object for the specified git repo. -}
new :: Git.Repo -> IO AnnexState
new gitrepo = newState <$> Git.configRead gitrepo
{- performs an action in the Annex monad -}
run :: AnnexState -> Annex a -> IO (a, AnnexState)
run s a = runStateT (runAnnex a) s
eval :: AnnexState -> Annex a -> IO a
eval s a = evalStateT (runAnnex a) s
{- Gets a value from the internal state, selected by the passed value
- constructor. -}
getState :: (AnnexState -> a) -> Annex a
getState = gets
{- Applies a state mutation function to change the internal state.
-
- Example: changeState $ \s -> s { quiet = True }
-}
changeState :: (AnnexState -> AnnexState) -> Annex ()
changeState = modify
{- Returns the annex's git repository. -}
gitRepo :: Annex Git.Repo
gitRepo = getState repo
{- Runs an IO action in the annex's git repository. -}
inRepo :: (Git.Repo -> IO a) -> Annex a
inRepo a = liftIO . a =<< gitRepo
{- Extracts a value from the annex's git repisitory. -}
fromRepo :: (Git.Repo -> a) -> Annex a
fromRepo a = a <$> gitRepo