git-annex/Logs/UUIDBased.hs
Joey Hess 4631d1ab56
Fix build with attoparsec-0.14
It changed parseOnly in the ByteString.Lazy module to take a lazy, not
strict ByteString. In all these cases though, we actually had a strict
ByteString, so the most efficient fix, which also happens to avoid needing
ifdefs, is to use the non-lazy module instead.

This commit was sponsored by Denis Dzyubenko on Patreon.
2021-03-24 12:11:50 -04:00

96 lines
2.7 KiB
Haskell

{- git-annex uuid-based logs
-
- This is used to store information about UUIDs in a way that can
- be union merged.
-
- The old format looks like: "UUID[ INFO[ timestamp=foo]]"
- The timestamp is last for backwards compatability reasons,
- and may not be present on very old log lines.
-
- New uuid based logs instead use the form: "timestamp UUID INFO"
-
- Copyright 2011-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings, TupleSections #-}
module Logs.UUIDBased (
Log,
LogEntry(..),
VectorClock,
currentVectorClock,
parseLogOld,
parseLogNew,
parseLogOldWithUUID,
buildLogOld,
buildLogNew,
changeLog,
addLog,
simpleMap,
) where
import qualified Data.Map as M
import Common
import Types.UUID
import Annex.VectorClock
import Logs.MapLog
import Logs.Line
import qualified Data.ByteString as S
import qualified Data.ByteString.Lazy as L
import qualified Data.Attoparsec.ByteString as A
import qualified Data.Attoparsec.ByteString.Lazy as AL
import qualified Data.Attoparsec.ByteString.Char8 as A8
import Data.ByteString.Builder
import qualified Data.DList as D
type Log v = MapLog UUID v
buildLogOld :: (v -> Builder) -> Log v -> Builder
buildLogOld builder = mconcat . map genline . M.toList
where
genline (u, LogEntry c@(VectorClock {}) v) =
buildUUID u <> sp <> builder v <> sp <>
byteString "timestamp=" <> buildVectorClock c <> nl
genline (u, LogEntry Unknown v) =
buildUUID u <> sp <> builder v <> nl
sp = charUtf8 ' '
nl = charUtf8 '\n'
parseLogOld :: A.Parser a -> L.ByteString -> Log a
parseLogOld = parseLogOldWithUUID . const
parseLogOldWithUUID :: (UUID -> A.Parser a) -> L.ByteString -> Log a
parseLogOldWithUUID parser = fromMaybe M.empty . AL.maybeResult
. AL.parse (logParserOld parser)
logParserOld :: (UUID -> A.Parser a) -> A.Parser (Log a)
logParserOld parser = M.fromListWith best <$> parseLogLines go
where
go = do
u <- toUUID <$> A8.takeWhile1 (/= ' ')
(dl, ts) <- accumval D.empty
v <- either fail return $ A.parseOnly (parser u <* A.endOfInput)
(S.intercalate " " $ D.toList dl)
return (u, LogEntry ts v)
accumval dl =
((dl,) <$> parsetimestamp)
<|> (A8.char ' ' *> (A8.takeWhile (/= ' ')) >>= accumval . D.snoc dl)
parsetimestamp =
(A8.string " timestamp=" *> vectorClockParser <* A.endOfInput)
<|> (const Unknown <$> A.endOfInput)
buildLogNew :: (v -> Builder) -> Log v -> Builder
buildLogNew = buildMapLog buildUUID
parseLogNew :: A.Parser v -> L.ByteString -> Log v
parseLogNew = parseMapLog (toUUID <$> A.takeByteString)
changeLog :: VectorClock -> UUID -> v -> Log v -> Log v
changeLog = changeMapLog
addLog :: UUID -> LogEntry v -> Log v -> Log v
addLog = addMapLog