git-annex/Annex.hs
Joey Hess cd865c3b8f Switch to using relative paths to the git repository.
This allows the git repository to be moved while git-annex is running in
it, with fewer problems.

On Windows, this avoids some of the problems with the absurdly small
MAX_PATH of 260 bytes. In particular, git-annex repositories should
work in deeper/longer directory structures than before. See
http://git-annex.branchable.com/bugs/__34__git-annex:_direct:_1_failed__34___on_Windows/

There are several possible ways this change could break git-annex:

1. If it changes its working directory while it's running, that would
   be Bad News. Good news everyone! git-annex never does so. It would also
   break thread safety, so all such things were stomped out long ago.

2. parentDir "." -> "" which is not a valid path. I had to fix one
   instace of this, and I should probably wipe all calls to parentDir out
   of the git-annex code base; it was never a good idea.

3. Things like relPathDirToFile require absolute input paths,
   and code assumes that the git repo path is absolute and passes it to it
   as-is. In the case of relPathDirToFile, I converted it to not make
   this assumption.

Currently, the test suite has 16 failures.
2015-01-06 16:19:41 -04:00

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{- git-annex monad
-
- Copyright 2010-2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP, GeneralizedNewtypeDeriving, PackageImports #-}
module Annex (
Annex,
AnnexState(..),
new,
run,
eval,
getState,
changeState,
withState,
setFlag,
setField,
setOutput,
getFlag,
getField,
addCleanup,
gitRepo,
inRepo,
fromRepo,
calcRepo,
getGitConfig,
changeGitConfig,
changeGitRepo,
getRemoteGitConfig,
withCurrentState,
) where
import Common
import qualified Git
import qualified Git.Config
import Annex.Direct.Fixup
import Git.CatFile
import Git.CheckAttr
import Git.CheckIgnore
import Git.SharedRepository
import qualified Git.Hook
import qualified Git.Queue
import Types.Key
import Types.Backend
import Types.GitConfig
import qualified Types.Remote
import Types.Crypto
import Types.BranchState
import Types.TrustLevel
import Types.Group
import Types.Messages
import Types.UUID
import Types.FileMatcher
import Types.NumCopies
import Types.LockPool
import Types.MetaData
import Types.DesktopNotify
import Types.CleanupActions
#ifdef WITH_QUVI
import Utility.Quvi (QuviVersion)
#endif
import Utility.InodeCache
import Utility.Url
import "mtl" Control.Monad.Reader
import Control.Concurrent
import qualified Data.Map as M
import qualified Data.Set as S
{- git-annex's monad is a ReaderT around an AnnexState stored in a MVar.
- The MVar is not exposed outside this module.
-
- Note that when an Annex action fails and the exception is caught,
- ny changes the action has made to the AnnexState are retained,
- due to the use of the MVar to store the state.
-}
newtype Annex a = Annex { runAnnex :: ReaderT (MVar AnnexState) IO a }
deriving (
Monad,
MonadIO,
MonadReader (MVar AnnexState),
MonadCatch,
MonadThrow,
#if MIN_VERSION_exceptions(0,6,0)
MonadMask,
#endif
Functor,
Applicative
)
-- internal state storage
data AnnexState = AnnexState
{ repo :: Git.Repo
, gitconfig :: GitConfig
, backends :: [BackendA Annex]
, remotes :: [Types.Remote.RemoteA Annex]
, remoteannexstate :: M.Map UUID AnnexState
, output :: MessageState
, force :: Bool
, fast :: Bool
, auto :: Bool
, daemon :: Bool
, branchstate :: BranchState
, repoqueue :: Maybe Git.Queue.Queue
, catfilehandles :: M.Map FilePath CatFileHandle
, checkattrhandle :: Maybe CheckAttrHandle
, checkignorehandle :: Maybe (Maybe CheckIgnoreHandle)
, forcebackend :: Maybe String
, globalnumcopies :: Maybe NumCopies
, forcenumcopies :: Maybe NumCopies
, limit :: ExpandableMatcher Annex
, uuidmap :: Maybe UUIDMap
, preferredcontentmap :: Maybe (FileMatcherMap Annex)
, requiredcontentmap :: Maybe (FileMatcherMap Annex)
, shared :: Maybe SharedRepository
, forcetrust :: TrustMap
, trustmap :: Maybe TrustMap
, groupmap :: Maybe GroupMap
, ciphers :: M.Map StorableCipher Cipher
, lockpool :: LockPool
, flags :: M.Map String Bool
, fields :: M.Map String String
, modmeta :: [ModMeta]
, cleanup :: M.Map CleanupAction (Annex ())
, sentinalstatus :: Maybe SentinalStatus
, useragent :: Maybe String
, errcounter :: Integer
, unusedkeys :: Maybe (S.Set Key)
, tempurls :: M.Map Key URLString
#ifdef WITH_QUVI
, quviversion :: Maybe QuviVersion
#endif
, existinghooks :: M.Map Git.Hook.Hook Bool
, desktopnotify :: DesktopNotify
}
newState :: GitConfig -> Git.Repo -> AnnexState
newState c r = AnnexState
{ repo = r
, gitconfig = c
, backends = []
, remotes = []
, remoteannexstate = M.empty
, output = defaultMessageState
, force = False
, fast = False
, auto = False
, daemon = False
, branchstate = startBranchState
, repoqueue = Nothing
, catfilehandles = M.empty
, checkattrhandle = Nothing
, checkignorehandle = Nothing
, forcebackend = Nothing
, globalnumcopies = Nothing
, forcenumcopies = Nothing
, limit = BuildingMatcher []
, uuidmap = Nothing
, preferredcontentmap = Nothing
, requiredcontentmap = Nothing
, shared = Nothing
, forcetrust = M.empty
, trustmap = Nothing
, groupmap = Nothing
, ciphers = M.empty
, lockpool = M.empty
, flags = M.empty
, fields = M.empty
, modmeta = []
, cleanup = M.empty
, sentinalstatus = Nothing
, useragent = Nothing
, errcounter = 0
, unusedkeys = Nothing
, tempurls = M.empty
#ifdef WITH_QUVI
, quviversion = Nothing
#endif
, existinghooks = M.empty
, desktopnotify = mempty
}
{- Makes an Annex state object for the specified git repo.
- Ensures the config is read, if it was not already. -}
new :: Git.Repo -> IO AnnexState
new r = do
r' <- Git.Config.read =<< Git.relPath r
let c = extractGitConfig r'
newState c <$> if annexDirect c then fixupDirect r' else return r'
{- Performs an action in the Annex monad from a starting state,
- returning a new state. -}
run :: AnnexState -> Annex a -> IO (a, AnnexState)
run s a = do
mvar <- newMVar s
r <- runReaderT (runAnnex a) mvar
s' <- takeMVar mvar
return (r, s')
{- Performs an action in the Annex monad from a starting state,
- and throws away the new state. -}
eval :: AnnexState -> Annex a -> IO a
eval s a = do
mvar <- newMVar s
runReaderT (runAnnex a) mvar
getState :: (AnnexState -> v) -> Annex v
getState selector = do
mvar <- ask
s <- liftIO $ readMVar mvar
return $ selector s
changeState :: (AnnexState -> AnnexState) -> Annex ()
changeState modifier = do
mvar <- ask
liftIO $ modifyMVar_ mvar $ return . modifier
withState :: (AnnexState -> (AnnexState, b)) -> Annex b
withState modifier = do
mvar <- ask
liftIO $ modifyMVar mvar $ return . modifier
{- Sets a flag to True -}
setFlag :: String -> Annex ()
setFlag flag = changeState $ \s ->
s { flags = M.insertWith' const flag True $ flags s }
{- Sets a field to a value -}
setField :: String -> String -> Annex ()
setField field value = changeState $ \s ->
s { fields = M.insertWith' const field value $ fields s }
{- Adds a cleanup action to perform. -}
addCleanup :: CleanupAction -> Annex () -> Annex ()
addCleanup k a = changeState $ \s ->
s { cleanup = M.insertWith' const k a $ cleanup s }
{- Sets the type of output to emit. -}
setOutput :: OutputType -> Annex ()
setOutput o = changeState $ \s ->
s { output = (output s) { outputType = o } }
{- Checks if a flag was set. -}
getFlag :: String -> Annex Bool
getFlag flag = fromMaybe False . M.lookup flag <$> getState flags
{- Gets the value of a field. -}
getField :: String -> Annex (Maybe String)
getField field = M.lookup field <$> getState fields
{- 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
{- Calculates a value from an annex's git repository and its GitConfig. -}
calcRepo :: (Git.Repo -> GitConfig -> IO a) -> Annex a
calcRepo a = do
s <- getState id
liftIO $ a (repo s) (gitconfig s)
{- Gets the GitConfig settings. -}
getGitConfig :: Annex GitConfig
getGitConfig = getState gitconfig
{- Modifies a GitConfig setting. -}
changeGitConfig :: (GitConfig -> GitConfig) -> Annex ()
changeGitConfig a = changeState $ \s -> s { gitconfig = a (gitconfig s) }
{- Changing the git Repo data also involves re-extracting its GitConfig. -}
changeGitRepo :: Git.Repo -> Annex ()
changeGitRepo r = changeState $ \s -> s
{ repo = r
, gitconfig = extractGitConfig r
}
{- Gets the RemoteGitConfig from a remote, given the Git.Repo for that
- remote. -}
getRemoteGitConfig :: Git.Repo -> Annex RemoteGitConfig
getRemoteGitConfig r = do
g <- gitRepo
return $ extractRemoteGitConfig g (Git.repoDescribe r)
{- Converts an Annex action into an IO action, that runs with a copy
- of the current Annex state.
-
- Use with caution; the action should not rely on changing the
- state, as it will be thrown away. -}
withCurrentState :: Annex a -> Annex (IO a)
withCurrentState a = do
s <- getState id
return $ eval s a