git-annex/Logs/PreferredContent/Raw.hs
Joey Hess 05989556a2
start implementing hidden git-annex repositories
This adds a separate journal, which does not currently get committed to
an index, but is planned to be committed to .git/annex/index-private.

Changes that are regarding a UUID that is private will get written to
this journal, and so will not be published into the git-annex branch.

All log writing should have been made to indicate the UUID it's
regarding, though I've not verified this yet.

Currently, no UUIDs are treated as private yet, a way to configure that
is needed.

The implementation is careful to not add any additional IO work when
privateUUIDsKnown is False. It will skip looking at the private journal
at all. So this should be free, or nearly so, unless the feature is
used. When it is used, all branch reads will be about twice as expensive.

It is very lucky -- or very prudent design -- that Annex.Branch.change
and maybeChange are the only ways to change a file on the branch,
and Annex.Branch.set is only internal use. That let Annex.Branch.get
always yield any private information that has been recorded, without
the risk that Annex.Branch.set might be called, with a non-private UUID,
and end up leaking the private information into the git-annex branch.

And, this relies on the way git-annex union merges the git-annex branch.
When reading a file, there can be a public and a private version, and
they are just concacenated together. That will be handled the same as if
there were two diverged git-annex branches that got union merged.
2021-04-20 15:04:53 -04:00

84 lines
3 KiB
Haskell

{- unparsed preferred content expressions
-
- Copyright 2012-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Logs.PreferredContent.Raw where
import Annex.Common
import qualified Annex.Branch
import qualified Annex
import Logs
import Logs.UUIDBased
import Logs.MapLog
import Types.StandardGroups
import Types.Group
import qualified Data.Map as M
import qualified Data.ByteString.Lazy as L
import qualified Data.Attoparsec.ByteString.Lazy as A
import Data.ByteString.Builder
{- Changes the preferred content configuration of a remote. -}
preferredContentSet :: UUID -> PreferredContentExpression -> Annex ()
preferredContentSet = setLog preferredContentLog
requiredContentSet :: UUID -> PreferredContentExpression -> Annex ()
requiredContentSet = setLog requiredContentLog
setLog :: RawFilePath -> UUID -> PreferredContentExpression -> Annex ()
setLog logfile uuid@(UUID _) val = do
c <- currentVectorClock
Annex.Branch.change (Annex.Branch.RegardingUUID [uuid]) logfile $
buildLogOld buildPreferredContentExpression
. changeLog c uuid val
. parseLogOld parsePreferredContentExpression
Annex.changeState $ \s -> s
{ Annex.preferredcontentmap = Nothing
, Annex.requiredcontentmap = Nothing
}
setLog _ NoUUID _ = error "unknown UUID; cannot modify"
{- Changes the preferred content configuration of a group. -}
groupPreferredContentSet :: Group -> PreferredContentExpression -> Annex ()
groupPreferredContentSet g val = do
c <- currentVectorClock
Annex.Branch.change
(Annex.Branch.RegardingUUID [])
groupPreferredContentLog $
buildGroupPreferredContent
. changeMapLog c g val
. parseGroupPreferredContent
Annex.changeState $ \s -> s { Annex.preferredcontentmap = Nothing }
parseGroupPreferredContent :: L.ByteString -> MapLog Group String
parseGroupPreferredContent = parseMapLog parsegroup parsestring
where
parsegroup = Group <$> A.takeByteString
parsestring = decodeBS <$> A.takeByteString
buildGroupPreferredContent :: MapLog Group PreferredContentExpression -> Builder
buildGroupPreferredContent = buildMapLog buildgroup buildexpr
where
buildgroup (Group g) = byteString g
buildexpr = byteString . encodeBS
parsePreferredContentExpression :: A.Parser PreferredContentExpression
parsePreferredContentExpression = decodeBS <$> A.takeByteString
buildPreferredContentExpression :: PreferredContentExpression -> Builder
buildPreferredContentExpression = byteString . encodeBS
preferredContentMapRaw :: Annex (M.Map UUID PreferredContentExpression)
preferredContentMapRaw = simpleMap . parseLogOld parsePreferredContentExpression
<$> Annex.Branch.get preferredContentLog
requiredContentMapRaw :: Annex (M.Map UUID PreferredContentExpression)
requiredContentMapRaw = simpleMap . parseLogOld parsePreferredContentExpression
<$> Annex.Branch.get requiredContentLog
groupPreferredContentMapRaw :: Annex (M.Map Group PreferredContentExpression)
groupPreferredContentMapRaw = simpleMap . parseGroupPreferredContent
<$> Annex.Branch.get groupPreferredContentLog