git-annex/Logs/Group.hs
Joey Hess 6280af2901
generate more compact git-annex branch for imports
Especially from borg, where the content identifier logs
all end up being the same identical file!

But also, for other imports, the location tracking logs can,
in some cases, be identical files.

Bonus optimisation: Avoid looking up (and parsing when set)
GIT_ANNEX_VECTOR_CLOCK env var every time a log is written to.
Although the lookup does happen at startup even when no
log will be written now.
2020-12-23 15:25:16 -04:00

99 lines
2.9 KiB
Haskell

{- git-annex group log
-
- Copyright 2012, 2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Logs.Group (
groupLog,
groupChange,
groupSet,
lookupGroups,
groupMap,
groupMapLoad,
getStandardGroup,
inUnwantedGroup
) where
import qualified Data.Map as M
import qualified Data.Set as S
import qualified Data.Attoparsec.ByteString as A
import qualified Data.Attoparsec.ByteString.Char8 as A8
import Data.ByteString.Builder
import Annex.Common
import Logs
import qualified Annex.Branch
import qualified Annex
import Logs.UUIDBased
import Types.Group
import Types.StandardGroups
{- Returns the groups of a given repo UUID. -}
lookupGroups :: UUID -> Annex (S.Set Group)
lookupGroups u = (fromMaybe S.empty . M.lookup u) . groupsByUUID <$> groupMap
{- Applies a set modifier to change the groups for a uuid in the groupLog. -}
groupChange :: UUID -> (S.Set Group -> S.Set Group) -> Annex ()
groupChange uuid@(UUID _) modifier = do
curr <- lookupGroups uuid
c <- currentVectorClock
Annex.Branch.change groupLog $
buildLogOld buildGroup . changeLog c uuid (modifier curr) . parseLogOld parseGroup
-- The changed group invalidates the preferred content cache.
Annex.changeState $ \s -> s
{ Annex.groupmap = Nothing
, Annex.preferredcontentmap = Nothing
}
groupChange NoUUID _ = error "unknown UUID; cannot modify"
buildGroup :: S.Set Group -> Builder
buildGroup = go . S.toList
where
go [] = mempty
go (g:gs) = bld g <> mconcat [ charUtf8 ' ' <> bld g' | g' <- gs ]
bld (Group g) = byteString g
parseGroup :: A.Parser (S.Set Group)
parseGroup = S.fromList <$> go []
where
go l = (A.endOfInput *> pure l)
<|> ((getgroup <* A8.char ' ') >>= go . (:l))
<|> ((:l) <$> getgroup)
-- allow extra writespace before or after a group name
<|> (A8.char ' ' >>= const (go l))
getgroup = Group <$> A8.takeWhile1 (/= ' ')
groupSet :: UUID -> S.Set Group -> Annex ()
groupSet u g = groupChange u (const g)
{- The map is cached for speed. -}
groupMap :: Annex GroupMap
groupMap = maybe groupMapLoad return =<< Annex.getState Annex.groupmap
{- Loads the map, updating the cache. -}
groupMapLoad :: Annex GroupMap
groupMapLoad = do
m <- makeGroupMap . simpleMap . parseLogOld parseGroup
<$> Annex.Branch.get groupLog
Annex.changeState $ \s -> s { Annex.groupmap = Just m }
return m
makeGroupMap :: M.Map UUID (S.Set Group) -> GroupMap
makeGroupMap byuuid = GroupMap byuuid bygroup
where
bygroup = M.fromListWith S.union $
concatMap explode $ M.toList byuuid
explode (u, s) = map (\g -> (g, S.singleton u)) (S.toList s)
{- If a repository is in exactly one standard group, returns it. -}
getStandardGroup :: S.Set Group -> Maybe StandardGroup
getStandardGroup s = case mapMaybe toStandardGroup $ S.toList s of
[g] -> Just g
_ -> Nothing
inUnwantedGroup :: UUID -> Annex Bool
inUnwantedGroup u = elem UnwantedGroup
. mapMaybe toStandardGroup . S.toList <$> lookupGroups u