git-annex/Messages/Internal.hs
Joey Hess a108235565
better locking for json with -J
Avoid threads emitting json at the same time and scrambling, which was
still possible even with the buffering, just less likely.

Converted json IO actions to JSONChunk data too.
2016-09-09 15:51:34 -04:00

70 lines
1.9 KiB
Haskell

{- git-annex output messages, including concurrent output to display regions
-
- Copyright 2010-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Messages.Internal where
import Common
import Annex
import Types.Messages
import Messages.Concurrent
import Messages.JSON
import qualified Data.ByteString.Lazy as B
withMessageState :: (MessageState -> Annex a) -> Annex a
withMessageState a = Annex.getState Annex.output >>= a
outputMessage :: JSONChunk -> String -> Annex ()
outputMessage = outputMessage' False
outputMessageFinal :: JSONChunk -> String -> Annex ()
outputMessageFinal = outputMessage' True
outputMessage' :: Bool -> JSONChunk -> String -> Annex ()
outputMessage' endmessage json msg = withMessageState $ \s -> case outputType s of
NormalOutput
| concurrentOutputEnabled s -> concurrentMessage s False msg q
| otherwise -> liftIO $ flushed $ putStr msg
JSONOutput _ -> void $ outputJSON json endmessage s
QuietOutput -> q
outputJSON :: JSONChunk -> Bool -> MessageState -> Annex Bool
outputJSON json endmessage s = case outputType s of
JSONOutput withprogress
| withprogress || concurrentOutputEnabled s -> do
-- Buffer json fragments until end is reached.
if endmessage
then do
Annex.changeState $ \st ->
st { Annex.output = s { jsonBuffer = none } }
liftIO $ flushed $ emit b
else Annex.changeState $ \st ->
st { Annex.output = s { jsonBuffer = b } }
return True
| otherwise -> do
liftIO $ flushed $ emit json
return True
_ -> return False
where
b = jsonBuffer s `B.append` json
outputError :: String -> Annex ()
outputError msg = withMessageState $ \s ->
if concurrentOutputEnabled s
then concurrentMessage s True msg go
else go
where
go = liftIO $ do
hFlush stdout
hPutStr stderr msg
hFlush stderr
q :: Monad m => m ()
q = noop
flushed :: IO () -> IO ()
flushed a = a >> hFlush stdout