convert transitions.log to attoparsec and bytestring-builder

Not likely to be any speed gain here, but this completes porting every
log file over.

And, it let me get rid of code copied from ghc and modified, so
simplifying the licensing.

2 files changed, 46 insertions, 77 deletions

diff --git a/Logs/Line.hs b/Logs/Line.hs
index 716ee8be87..3bacc29027 100644
--- a/Logs/Line.hs
+++ b/Logs/Line.hs
@@ -1,38 +1,9 @@
-{- 
-
-The Glasgow Haskell Compiler License
-
-Copyright 2001, The University Court of the University of Glasgow.
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-- Redistributions of source code must retain the above copyright notice,
-this list of conditions and the following disclaimer.
-
-- Redistributions in binary form must reproduce the above copyright notice,
-this list of conditions and the following disclaimer in the documentation
-and/or other materials provided with the distribution.
-
-- Neither name of the University nor the names of its contributors may be
-used to endorse or promote products derived from this software without
-specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY COURT OF THE UNIVERSITY OF
-GLASGOW AND THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
-INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
-FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
-UNIVERSITY COURT OF THE UNIVERSITY OF GLASGOW OR THE CONTRIBUTORS BE LIABLE
-FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
-DAMAGE.
-
--}
+{- line based log files
+ -
+ - Copyright 2019 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL version 3 or higher.
+ -}
 
 module Logs.Line where
 
@@ -42,20 +13,6 @@ import qualified Data.Attoparsec.ByteString.Lazy as A
 import Data.Attoparsec.ByteString.Char8 (isEndOfLine)
 import qualified Data.DList as D
 
--- This is the same as Data.List.lines, with \r added.
--- This works around some versions of git-annex which wrote \r
--- into git-annex branch files on Windows. Those \r's sometimes
--- accumulated over time, so a single line could end with multiple \r's
--- before the \n.
-splitLines :: String -> [String]
-splitLines "" =  []
-splitLines s =  cons (case break (\c -> c == '\n' || c == '\r') s of
-	(l, s') -> (l, case s' of
-		[]      -> []
-		_:s''   -> splitLines s''))
-  where
-	cons ~(h, t) = h : t
-
 {- Applies a parser to each line of a log file.
  -
  - If the parser fails to parse a line, that line is skipped, instead of
diff --git a/Logs/Transitions.hs b/Logs/Transitions.hs
index d44bfd75b6..550727451d 100644
--- a/Logs/Transitions.hs
+++ b/Logs/Transitions.hs
@@ -7,7 +7,7 @@
  - done that is listed in the remote branch by checking that the local
  - branch contains the same transition, with the same or newer start time.
  -
- - Copyright 2013 Joey Hess <id@joeyh.name>
+ - Copyright 2013-2019 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -19,7 +19,12 @@ import Annex.VectorClock
 import Logs.Line
 
 import qualified Data.Set as S
+import Data.Either
+import Data.ByteString (ByteString)
+import Data.ByteString.Builder
 import qualified Data.ByteString.Lazy as L
+import qualified Data.Attoparsec.ByteString.Lazy as A
+import qualified Data.Attoparsec.ByteString.Char8 as A8
 
 transitionsLog :: FilePath
 transitionsLog = "transitions.log"
@@ -31,7 +36,8 @@ data Transition
 
 data TransitionLine = TransitionLine
 	{ transitionStarted :: VectorClock
-	, transition :: Transition
+	-- New transitions that we don't know about yet are preserved.
+	, transition :: Either ByteString Transition
 	} deriving (Ord, Eq)
 
 type Transitions = S.Set TransitionLine
@@ -44,44 +50,50 @@ noTransitions :: Transitions
 noTransitions = S.empty
 
 addTransition :: VectorClock -> Transition -> Transitions -> Transitions
-addTransition c t = S.insert $ TransitionLine c t
+addTransition c t = S.insert $ TransitionLine c (Right t)
 
-showTransitions :: Transitions -> String
-showTransitions = unlines . map showTransitionLine . S.elems
-
-{- If the log contains new transitions we don't support, returns Nothing. -}
-parseTransitions :: String -> Maybe Transitions
-parseTransitions = check . map parseTransitionLine . splitLines
-  where
-	check l
-		| all isJust l = Just $ S.fromList $ catMaybes l
-		| otherwise = Nothing
-
-parseTransitionsStrictly :: String -> String -> Transitions
-parseTransitionsStrictly source = fromMaybe badsource . parseTransitions
+buildTransitions :: Transitions -> Builder
+buildTransitions = mconcat . map genline . S.elems
   where
-	badsource = giveup $ "unknown transitions listed in " ++ source ++ "; upgrade git-annex!"
+	genline tl = buildt (transition tl) <> charUtf8 ' '
+		<> buildVectorClock (transitionStarted tl) <> charUtf8 '\n'
+	buildt (Left b) = byteString b
+	buildt (Right t) = byteString (encodeBS (show t))
+
+parseTransitions :: L.ByteString -> Transitions
+parseTransitions = fromMaybe S.empty . A.maybeResult . A.parse
+	(S.fromList <$> parseLogLines transitionLineParser)
+
+parseTransitionsStrictly :: String -> L.ByteString -> Transitions
+parseTransitionsStrictly source b =
+	let ts = parseTransitions b
+	in if S.null $ S.filter (isLeft . transition) ts
+		then ts
+		else giveup $ "unknown transitions listed in " ++ source ++ "; upgrade git-annex!"
 
 showTransitionLine :: TransitionLine -> String
 showTransitionLine (TransitionLine c t) = unwords [show t, formatVectorClock c]
 
-parseTransitionLine :: String -> Maybe TransitionLine
-parseTransitionLine s = TransitionLine
-	<$> parseVectorClock cs
-	<*> readish ts
+transitionLineParser :: A.Parser TransitionLine
+transitionLineParser = do
+	t <- (parsetransition <$> A.takeByteString)
+	_ <- A8.char ' '
+	c <- vectorClockParser
+	return $ TransitionLine c t
   where
-	ws = words s
-	ts = Prelude.head ws
-	cs = unwords $ Prelude.tail ws
+	parsetransition b = case readish (decodeBS b) of
+		Just t -> Right t
+		Nothing -> Left b
 
 combineTransitions :: [Transitions] -> Transitions
 combineTransitions = S.unions
 
-transitionList :: Transitions -> [Transition]
-transitionList = nub . map transition . S.elems
+{- Unknown types of transitions are omitted. -}
+knownTransitionList :: Transitions -> [Transition]
+knownTransitionList = nub . rights . map transition . S.elems
 
 {- Typically ran with Annex.Branch.change, but we can't import Annex.Branch
  - here since it depends on this module. -}
-recordTransitions :: (FilePath -> (L.ByteString -> L.ByteString) -> Annex ()) -> Transitions -> Annex ()
+recordTransitions :: (FilePath -> (L.ByteString -> Builder) -> Annex ()) -> Transitions -> Annex ()
 recordTransitions changer t = changer transitionsLog $
-	encodeBL . showTransitions . S.union t . parseTransitionsStrictly "local" . decodeBL
+	buildTransitions . S.union t . parseTransitionsStrictly "local"