4b55afe9e9
With a really nice optimisation that keeps it from having any overhead in normal operation! This commit was sponsored by Ulises Vitulli.
260 lines
6.8 KiB
Haskell
260 lines
6.8 KiB
Haskell
{- git-annex monad
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-
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- Copyright 2010-2013 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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{-# LANGUAGE GeneralizedNewtypeDeriving, PackageImports #-}
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module Annex (
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Annex,
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AnnexState(..),
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PreferredContentMap,
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new,
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run,
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eval,
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getState,
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changeState,
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setFlag,
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setField,
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setOutput,
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getFlag,
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getField,
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addCleanup,
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gitRepo,
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inRepo,
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fromRepo,
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calcRepo,
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getGitConfig,
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changeGitConfig,
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changeGitRepo,
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withCurrentState,
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) where
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import "mtl" Control.Monad.Reader
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import "MonadCatchIO-transformers" Control.Monad.CatchIO
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import System.Posix.Types (Fd)
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import Control.Concurrent
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import Common
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import qualified Git
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import qualified Git.Config
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import Annex.Direct.Fixup
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import Git.CatFile
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import Git.CheckAttr
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import Git.CheckIgnore
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import Git.SharedRepository
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import qualified Git.Queue
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import Types.Key
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import Types.Backend
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import Types.GitConfig
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import qualified Types.Remote
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import Types.Crypto
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import Types.BranchState
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import Types.TrustLevel
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import Types.Group
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import Types.Messages
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import Types.UUID
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import Types.FileMatcher
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import Types.NumCopies
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import qualified Utility.Matcher
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import qualified Data.Map as M
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import qualified Data.Set as S
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{- git-annex's monad is a ReaderT around an AnnexState stored in a MVar.
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- This allows modifying the state in an exception-safe fashion.
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- The MVar is not exposed outside this module.
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-}
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newtype Annex a = Annex { runAnnex :: ReaderT (MVar AnnexState) IO a }
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deriving (
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Monad,
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MonadIO,
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MonadReader (MVar AnnexState),
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MonadCatchIO,
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Functor,
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Applicative
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)
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type Matcher a = Either [Utility.Matcher.Token a] (Utility.Matcher.Matcher a)
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type PreferredContentMap = M.Map UUID (Utility.Matcher.Matcher (S.Set UUID -> MatchInfo -> Annex Bool))
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-- internal state storage
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data AnnexState = AnnexState
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{ repo :: Git.Repo
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, gitconfig :: GitConfig
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, backends :: [BackendA Annex]
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, remotes :: [Types.Remote.RemoteA Annex]
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, output :: MessageState
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, force :: Bool
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, fast :: Bool
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, auto :: Bool
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, daemon :: Bool
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, branchstate :: BranchState
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, repoqueue :: Maybe Git.Queue.Queue
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, catfilehandles :: M.Map FilePath CatFileHandle
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, checkattrhandle :: Maybe CheckAttrHandle
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, checkignorehandle :: Maybe (Maybe CheckIgnoreHandle)
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, forcebackend :: Maybe String
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, globalnumcopies :: Maybe NumCopies
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, forcenumcopies :: Maybe NumCopies
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, limit :: Matcher (MatchInfo -> Annex Bool)
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, uuidmap :: Maybe UUIDMap
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, preferredcontentmap :: Maybe PreferredContentMap
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, shared :: Maybe SharedRepository
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, forcetrust :: TrustMap
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, trustmap :: Maybe TrustMap
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, groupmap :: Maybe GroupMap
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, ciphers :: M.Map StorableCipher Cipher
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, lockpool :: M.Map FilePath Fd
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, flags :: M.Map String Bool
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, fields :: M.Map String String
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, cleanup :: M.Map String (Annex ())
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, inodeschanged :: Maybe Bool
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, useragent :: Maybe String
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, errcounter :: Integer
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, unusedkeys :: Maybe (S.Set Key)
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}
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newState :: GitConfig -> Git.Repo -> AnnexState
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newState c r = AnnexState
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{ repo = r
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, gitconfig = c
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, backends = []
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, remotes = []
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, output = defaultMessageState
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, force = False
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, fast = False
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, auto = False
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, daemon = False
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, branchstate = startBranchState
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, repoqueue = Nothing
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, catfilehandles = M.empty
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, checkattrhandle = Nothing
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, checkignorehandle = Nothing
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, forcebackend = Nothing
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, globalnumcopies = Nothing
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, forcenumcopies = Nothing
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, limit = Left []
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, uuidmap = Nothing
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, preferredcontentmap = Nothing
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, shared = Nothing
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, forcetrust = M.empty
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, trustmap = Nothing
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, groupmap = Nothing
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, ciphers = M.empty
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, lockpool = M.empty
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, flags = M.empty
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, fields = M.empty
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, cleanup = M.empty
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, inodeschanged = Nothing
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, useragent = Nothing
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, errcounter = 0
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, unusedkeys = Nothing
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}
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{- Makes an Annex state object for the specified git repo.
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- Ensures the config is read, if it was not already. -}
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new :: Git.Repo -> IO AnnexState
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new r = do
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r' <- Git.Config.read r
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let c = extractGitConfig r'
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newState c <$> if annexDirect c then fixupDirect r' else return r'
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{- Performs an action in the Annex monad from a starting state,
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- returning a new state. -}
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run :: AnnexState -> Annex a -> IO (a, AnnexState)
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run s a = do
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mvar <- newMVar s
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r <- runReaderT (runAnnex a) mvar
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s' <- takeMVar mvar
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return (r, s')
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{- Performs an action in the Annex monad from a starting state,
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- and throws away the new state. -}
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eval :: AnnexState -> Annex a -> IO a
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eval s a = do
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mvar <- newMVar s
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runReaderT (runAnnex a) mvar
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getState :: (AnnexState -> v) -> Annex v
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getState selector = do
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mvar <- ask
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s <- liftIO $ readMVar mvar
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return $ selector s
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changeState :: (AnnexState -> AnnexState) -> Annex ()
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changeState modifier = do
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mvar <- ask
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liftIO $ modifyMVar_ mvar $ return . modifier
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{- Sets a flag to True -}
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setFlag :: String -> Annex ()
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setFlag flag = changeState $ \s ->
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s { flags = M.insertWith' const flag True $ flags s }
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{- Sets a field to a value -}
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setField :: String -> String -> Annex ()
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setField field value = changeState $ \s ->
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s { fields = M.insertWith' const field value $ fields s }
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{- Adds a cleanup action to perform. -}
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addCleanup :: String -> Annex () -> Annex ()
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addCleanup uid a = changeState $ \s ->
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s { cleanup = M.insertWith' const uid a $ cleanup s }
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{- Sets the type of output to emit. -}
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setOutput :: OutputType -> Annex ()
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setOutput o = changeState $ \s ->
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s { output = (output s) { outputType = o } }
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{- Checks if a flag was set. -}
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getFlag :: String -> Annex Bool
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getFlag flag = fromMaybe False . M.lookup flag <$> getState flags
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{- Gets the value of a field. -}
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getField :: String -> Annex (Maybe String)
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getField field = M.lookup field <$> getState fields
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{- Returns the annex's git repository. -}
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gitRepo :: Annex Git.Repo
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gitRepo = getState repo
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{- Runs an IO action in the annex's git repository. -}
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inRepo :: (Git.Repo -> IO a) -> Annex a
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inRepo a = liftIO . a =<< gitRepo
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{- Extracts a value from the annex's git repisitory. -}
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fromRepo :: (Git.Repo -> a) -> Annex a
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fromRepo a = a <$> gitRepo
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{- Calculates a value from an annex's git repository and its GitConfig. -}
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calcRepo :: (Git.Repo -> GitConfig -> IO a) -> Annex a
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calcRepo a = do
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s <- getState id
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liftIO $ a (repo s) (gitconfig s)
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{- Gets the GitConfig settings. -}
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getGitConfig :: Annex GitConfig
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getGitConfig = getState gitconfig
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{- Modifies a GitConfig setting. -}
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changeGitConfig :: (GitConfig -> GitConfig) -> Annex ()
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changeGitConfig a = changeState $ \s -> s { gitconfig = a (gitconfig s) }
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{- Changing the git Repo data also involves re-extracting its GitConfig. -}
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changeGitRepo :: Git.Repo -> Annex ()
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changeGitRepo r = changeState $ \s -> s
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{ repo = r
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, gitconfig = extractGitConfig r
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}
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{- Converts an Annex action into an IO action, that runs with a copy
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- of the current Annex state.
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-
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- Use with caution; the action should not rely on changing the
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- state, as it will be thrown away. -}
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withCurrentState :: Annex a -> Annex (IO a)
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withCurrentState a = do
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s <- getState id
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return $ eval s a
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