git-annex/Logs/Line.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

38 lines
1.2 KiB
Haskell

{- line based log files
-
- Copyright 2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Logs.Line where
import Common
import qualified Data.Attoparsec.ByteString as A
import Data.Attoparsec.ByteString.Char8 (isEndOfLine)
import qualified Data.DList as D
{- Applies a parser to each line of a log file.
-
- If the parser fails to parse a line, that line is skipped, instead of
- the overall parse failing. This is generally a good idea in case a newer
- version of git-annex somehow changed the format of the log file.
-
- Any combination of \r and \n are taken to be the end of the line.
- (Some versions of git-annex on Windows wrote \r into git-annex branch
- files, and multiple \r's sometimes accumulated.)
-
- The parser does not itself need to avoid parsing beyond the end of line;
- this is implemented only pass the content of a line to the parser.
-}
parseLogLines :: A.Parser a -> A.Parser [a]
parseLogLines parser = go D.empty
where
go dl = do
line <- A.takeTill isEndOfLine
A.skipWhile isEndOfLine
let dl' = case A.parseOnly parser line of
Left _ -> dl
Right v -> D.snoc dl v
(A.endOfInput *> return (D.toList dl')) <|> go dl'