git-annex/Annex.hs
Joey Hess f25eeedeac
initial implementation of --explain
Currently it only displays explanations of options like --in and --copies.

In the future, it should explain preferred content expression evaluation
and other decisions.

The explanations of a few things could be better. In particular,
"standard" will just appear as-is (or as "!standard" if it doesn't
match), rather than explaining why the standard preferred content expression
for the group matches or not.

Currently as implemented, it goes to stdout, and so commands like
git-annex find that have custom output will not display --explain
information. Perhaps that should change, dunno.

Sponsored-by: Dartmouth College's DANDI project
2023-07-25 16:52:57 -04:00

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{- git-annex monad
-
- Copyright 2010-2021 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE GeneralizedNewtypeDeriving, BangPatterns, PackageImports #-}
module Annex (
Annex,
AnnexState(..),
AnnexRead(..),
new,
run,
eval,
makeRunner,
getRead,
getState,
changeState,
withState,
setField,
setOutput,
getField,
addCleanupAction,
gitRepo,
inRepo,
fromRepo,
calcRepo,
calcRepo',
getGitConfig,
overrideGitConfig,
changeGitRepo,
adjustGitRepo,
addGitConfigOverride,
getGitConfigOverrides,
getRemoteGitConfig,
withCurrentState,
changeDirectory,
getGitRemotes,
incError,
) where
import Common
import qualified Git
import qualified Git.Config
import qualified Git.Construct
import Annex.Fixup
import Git.HashObject
import Git.CheckAttr
import Git.CheckIgnore
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.Concurrency
import Types.UUID
import Types.FileMatcher
import Types.NumCopies
import Types.LockCache
import Types.DesktopNotify
import Types.CleanupActions
import Types.AdjustedBranch
import Types.WorkerPool
import Types.IndexFiles
import Types.CatFileHandles
import Types.RemoteConfig
import Types.TransferrerPool
import Types.VectorClock
import Annex.VectorClock.Utility
import Annex.Debug.Utility
import qualified Database.Keys.Handle as Keys
import Utility.InodeCache
import Utility.Url
import Utility.ResourcePool
import Utility.HumanTime
import Git.Credential (CredentialCache(..))
import "mtl" Control.Monad.Reader
import Control.Concurrent
import Control.Concurrent.STM
import qualified Control.Monad.Fail as Fail
import qualified Data.Map.Strict as M
import qualified Data.Set as S
import Data.Time.Clock.POSIX
{- git-annex's monad is a ReaderT around an AnnexState stored in a MVar,
- and an AnnexRead. The MVar is not exposed outside this module.
-
- Note that when an Annex action fails and the exception is caught,
- any 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, AnnexRead) IO a }
deriving (
Monad,
MonadIO,
MonadReader (MVar AnnexState, AnnexRead),
MonadCatch,
MonadThrow,
MonadMask,
Fail.MonadFail,
Functor,
Applicative,
Alternative
)
-- Values that can be read, but not modified by an Annex action.
data AnnexRead = AnnexRead
{ activekeys :: TVar (M.Map Key ThreadId)
, activeremotes :: MVar (M.Map (Types.Remote.RemoteA Annex) Integer)
, keysdbhandle :: Keys.DbHandle
, sshstalecleaned :: TMVar Bool
, signalactions :: TVar (M.Map SignalAction (Int -> IO ()))
, transferrerpool :: TransferrerPool
, debugenabled :: Bool
, debugselector :: DebugSelector
, explainenabled :: Bool
, ciphers :: TMVar (M.Map StorableCipher Cipher)
, fast :: Bool
, force :: Bool
, forcenumcopies :: Maybe NumCopies
, forcemincopies :: Maybe MinCopies
, forcebackend :: Maybe String
, useragent :: Maybe String
, desktopnotify :: DesktopNotify
, gitcredentialcache :: TMVar CredentialCache
}
newAnnexRead :: GitConfig -> IO AnnexRead
newAnnexRead c = do
emptyactivekeys <- newTVarIO M.empty
emptyactiveremotes <- newMVar M.empty
kh <- Keys.newDbHandle
sc <- newTMVarIO False
si <- newTVarIO M.empty
tp <- newTransferrerPool
cm <- newTMVarIO M.empty
cc <- newTMVarIO (CredentialCache M.empty)
return $ AnnexRead
{ activekeys = emptyactivekeys
, activeremotes = emptyactiveremotes
, keysdbhandle = kh
, sshstalecleaned = sc
, signalactions = si
, transferrerpool = tp
, debugenabled = annexDebug c
, debugselector = debugSelectorFromGitConfig c
, explainenabled = False
, ciphers = cm
, fast = False
, force = False
, forcebackend = Nothing
, forcenumcopies = Nothing
, forcemincopies = Nothing
, useragent = Nothing
, desktopnotify = mempty
, gitcredentialcache = cc
}
-- Values that can change while running an Annex action.
data AnnexState = AnnexState
{ repo :: Git.Repo
, repoadjustment :: (Git.Repo -> IO Git.Repo)
, gitconfig :: GitConfig
, gitconfigadjustment :: (GitConfig -> GitConfig)
, gitconfigoverride :: [String]
, gitremotes :: Maybe [Git.Repo]
, gitconfiginodecache :: Maybe InodeCache
, backend :: Maybe (BackendA Annex)
, remotes :: [Types.Remote.RemoteA Annex]
, output :: MessageState
, concurrency :: ConcurrencySetting
, daemon :: Bool
, branchstate :: BranchState
, repoqueue :: Maybe (Git.Queue.Queue Annex)
, catfilehandles :: CatFileHandles
, hashobjecthandle :: Maybe (ResourcePool HashObjectHandle)
, checkattrhandle :: Maybe (ResourcePool CheckAttrHandle)
, checkignorehandle :: Maybe (ResourcePool CheckIgnoreHandle)
, globalnumcopies :: Maybe (Maybe NumCopies)
, globalmincopies :: Maybe (Maybe MinCopies)
, limit :: ExpandableMatcher Annex
, timelimit :: Maybe (Duration, POSIXTime)
, sizelimit :: Maybe (TVar Integer)
, uuiddescmap :: Maybe UUIDDescMap
, preferredcontentmap :: Maybe (FileMatcherMap Annex)
, requiredcontentmap :: Maybe (FileMatcherMap Annex)
, remoteconfigmap :: Maybe (M.Map UUID RemoteConfig)
, forcetrust :: TrustMap
, trustmap :: Maybe TrustMap
, groupmap :: Maybe GroupMap
, lockcache :: LockCache
, fields :: M.Map String String
, cleanupactions :: M.Map CleanupAction (Annex ())
, sentinalstatus :: Maybe SentinalStatus
, errcounter :: Integer
, reachedlimit :: Bool
, adjustedbranchrefreshcounter :: Integer
, unusedkeys :: Maybe (S.Set Key)
, tempurls :: M.Map Key URLString
, existinghooks :: M.Map Git.Hook.Hook Bool
, workers :: Maybe (TMVar (WorkerPool (AnnexState, AnnexRead)))
, cachedcurrentbranch :: (Maybe (Maybe Git.Branch, Maybe Adjustment))
, cachedgitenv :: Maybe (AltIndexFile, FilePath, [(String, String)])
, urloptions :: Maybe UrlOptions
, insmudgecleanfilter :: Bool
, getvectorclock :: IO CandidateVectorClock
}
newAnnexState :: GitConfig -> Git.Repo -> IO AnnexState
newAnnexState c r = do
o <- newMessageState
vc <- startVectorClock
return $ AnnexState
{ repo = r
, repoadjustment = return
, gitconfig = c
, gitconfigadjustment = id
, gitconfigoverride = []
, gitremotes = Nothing
, gitconfiginodecache = Nothing
, backend = Nothing
, remotes = []
, output = o
, concurrency = ConcurrencyCmdLine NonConcurrent
, daemon = False
, branchstate = startBranchState
, repoqueue = Nothing
, catfilehandles = catFileHandlesNonConcurrent
, hashobjecthandle = Nothing
, checkattrhandle = Nothing
, checkignorehandle = Nothing
, globalnumcopies = Nothing
, globalmincopies = Nothing
, limit = BuildingMatcher []
, timelimit = Nothing
, sizelimit = Nothing
, uuiddescmap = Nothing
, preferredcontentmap = Nothing
, requiredcontentmap = Nothing
, remoteconfigmap = Nothing
, forcetrust = M.empty
, trustmap = Nothing
, groupmap = Nothing
, lockcache = M.empty
, fields = M.empty
, cleanupactions = M.empty
, sentinalstatus = Nothing
, errcounter = 0
, reachedlimit = False
, adjustedbranchrefreshcounter = 0
, unusedkeys = Nothing
, tempurls = M.empty
, existinghooks = M.empty
, workers = Nothing
, cachedcurrentbranch = Nothing
, cachedgitenv = Nothing
, urloptions = Nothing
, insmudgecleanfilter = False
, getvectorclock = vc
}
{- Makes an Annex state object for the specified git repo.
- Ensures the config is read, if it was not already, and performs
- any necessary git repo fixups. -}
new :: Git.Repo -> IO (AnnexState, AnnexRead)
new r = do
r' <- Git.Config.read r
let c = extractGitConfig FromGitConfig r'
st <- newAnnexState c =<< fixupRepo r' c
rd <- newAnnexRead c
return (st, rd)
{- Performs an action in the Annex monad from a starting state,
- returning a new state. -}
run :: (AnnexState, AnnexRead) -> Annex a -> IO (a, (AnnexState, AnnexRead))
run (st, rd) a = do
mv <- newMVar st
run' mv rd a
run' :: MVar AnnexState -> AnnexRead -> Annex a -> IO (a, (AnnexState, AnnexRead))
run' mvar rd a = do
r <- runReaderT (runAnnex a) (mvar, rd)
st <- takeMVar mvar
return (r, (st, rd))
{- Performs an action in the Annex monad from a starting state,
- and throws away the changed state. -}
eval :: (AnnexState, AnnexRead) -> Annex a -> IO a
eval v a = fst <$> run v a
{- Makes a runner action, that allows diving into IO and from inside
- the IO action, running an Annex action. -}
makeRunner :: Annex (Annex a -> IO a)
makeRunner = do
(mvar, rd) <- ask
return $ \a -> do
(r, (s, _rd)) <- run' mvar rd a
putMVar mvar s
return r
getRead :: (AnnexRead -> v) -> Annex v
getRead selector = selector . snd <$> ask
getState :: (AnnexState -> v) -> Annex v
getState selector = do
mvar <- fst <$> ask
st <- liftIO $ readMVar mvar
return $ selector st
changeState :: (AnnexState -> AnnexState) -> Annex ()
changeState modifier = do
mvar <- fst <$> ask
liftIO $ modifyMVar_ mvar $ return . modifier
withState :: (AnnexState -> IO (AnnexState, b)) -> Annex b
withState modifier = do
mvar <- fst <$> ask
liftIO $ modifyMVar mvar modifier
{- Sets a field to a value -}
setField :: String -> String -> Annex ()
setField field value = changeState $ \st ->
st { fields = M.insert field value $ fields st }
{- Adds a cleanup action to perform. -}
addCleanupAction :: CleanupAction -> Annex () -> Annex ()
addCleanupAction k a = changeState $ \st ->
st { cleanupactions = M.insert k a $ cleanupactions st }
{- Sets the type of output to emit. -}
setOutput :: OutputType -> Annex ()
setOutput o = changeState $ \st ->
let m = output st
in st { output = m { outputType = adjustOutputType (outputType m) o } }
{- 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)
calcRepo' :: (Git.Repo -> GitConfig -> a) -> Annex a
calcRepo' f = do
s <- getState id
pure $ f (repo s) (gitconfig s)
{- Gets the GitConfig settings. -}
getGitConfig :: Annex GitConfig
getGitConfig = getState gitconfig
{- Overrides a GitConfig setting. The modification persists across
- reloads of the repo's config. -}
overrideGitConfig :: (GitConfig -> GitConfig) -> Annex ()
overrideGitConfig f = changeState $ \st -> st
{ gitconfigadjustment = gitconfigadjustment st . f
, gitconfig = f (gitconfig st)
}
{- Adds an adjustment to the Repo data. Adjustments persist across reloads
- of the repo's config.
-
- Note that the action may run more than once, and should avoid eg,
- appending the same value to a repo's config when run repeatedly.
-}
adjustGitRepo :: (Git.Repo -> IO Git.Repo) -> Annex ()
adjustGitRepo a = do
changeState $ \st -> st { repoadjustment = \r -> repoadjustment st r >>= a }
changeGitRepo =<< gitRepo
{- Adds git config setting, like "foo=bar". It will be passed with -c
- to git processes. The config setting is also recorded in the Repo,
- and the GitConfig is updated. -}
addGitConfigOverride :: String -> Annex ()
addGitConfigOverride v = do
adjustGitRepo $ \r ->
Git.Config.store (encodeBS v) Git.Config.ConfigList $
r { Git.gitGlobalOpts = go (Git.gitGlobalOpts r) }
changeState $ \st -> st { gitconfigoverride = v : gitconfigoverride st }
where
-- Remove any prior occurrence of the setting to avoid
-- building up many of them when the adjustment is run repeatedly,
-- and add the setting to the end.
go [] = [Param "-c", Param v]
go (Param "-c": Param v':rest) | v' == v = go rest
go (c:rest) = c : go rest
{- Values that were passed to addGitConfigOverride. -}
getGitConfigOverrides :: Annex [String]
getGitConfigOverrides = reverse <$> getState gitconfigoverride
{- Changing the git Repo data also involves re-extracting its GitConfig. -}
changeGitRepo :: Git.Repo -> Annex ()
changeGitRepo r = do
repoadjuster <- getState repoadjustment
gitconfigadjuster <- getState gitconfigadjustment
r' <- liftIO $ repoadjuster r
changeState $ \st -> st
{ repo = r'
, gitconfig = gitconfigadjuster $
extractGitConfig FromGitConfig r'
}
{- Gets the RemoteGitConfig from a remote, given the Git.Repo for that
- remote. -}
getRemoteGitConfig :: Git.Repo -> Annex RemoteGitConfig
getRemoteGitConfig r = do
g <- gitRepo
liftIO $ atomically $ 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
(mvar, rd) <- ask
st <- liftIO $ readMVar mvar
return $ eval (st, rd) a
{- It's not safe to use setCurrentDirectory in the Annex monad,
- because the git repo paths are stored relative.
- Instead, use this.
-}
changeDirectory :: FilePath -> Annex ()
changeDirectory d = do
r <- liftIO . Git.adjustPath absPath =<< gitRepo
liftIO $ setCurrentDirectory d
r' <- liftIO $ Git.relPath r
changeState $ \st -> st { repo = r' }
incError :: Annex ()
incError = changeState $ \st ->
let !c = errcounter st + 1
!st' = st { errcounter = c }
in st'
getGitRemotes :: Annex [Git.Repo]
getGitRemotes = do
st <- getState id
case gitremotes st of
Just rs -> return rs
Nothing -> do
rs <- liftIO $ Git.Construct.fromRemotes (repo st)
changeState $ \st' -> st' { gitremotes = Just rs }
return rs