-- | This module handles all display of output to the console when -- propellor is ensuring Properties. -- -- When two threads both try to display a message concurrently, -- the messages will be displayed sequentially. module Propellor.Message ( Trace(..), parseTrace, getMessageHandle, isConsole, forceConsole, actionMessage, actionMessageOn, warningMessage, infoMessage, errorMessage, stopPropellorMessage, messagesDone, createProcessConcurrent, withConcurrentOutput, ) where import System.Console.ANSI import System.IO import Control.Monad.IfElse import Control.Monad.IO.Class (liftIO, MonadIO) import System.IO.Unsafe (unsafePerformIO) import Control.Concurrent import System.Console.Concurrent import Control.Applicative import Prelude import Propellor.Types import Propellor.Types.Exception import Utility.Monad import Utility.Env import Utility.Exception import Utility.PartialPrelude -- | Serializable tracing. Export `PROPELLOR_TRACE=1` in the environment to -- make propellor emit these to stdout, in addition to its other output. data Trace = ActionStart (Maybe HostName) Desc | ActionEnd (Maybe HostName) Desc Result deriving (Read, Show) -- | Given a line read from propellor, if it's a serialized Trace, -- parses it. parseTrace :: String -> Maybe Trace parseTrace = readish data MessageHandle = MessageHandle { isConsole :: Bool , traceEnabled :: Bool } -- | A shared global variable for the MessageHandle. {-# NOINLINE globalMessageHandle #-} globalMessageHandle :: MVar MessageHandle globalMessageHandle = unsafePerformIO $ newMVar =<< MessageHandle <$> catchDefaultIO False (hIsTerminalDevice stdout) <*> ((== Just "1") <$> getEnv "PROPELLOR_TRACE") -- | Gets the global MessageHandle. getMessageHandle :: IO MessageHandle getMessageHandle = readMVar globalMessageHandle trace :: Trace -> IO () trace t = whenM (traceEnabled <$> getMessageHandle) $ putStrLn $ show t -- | Force console output. This can be used when stdout is not directly -- connected to a console, but is eventually going to be displayed at a -- console. forceConsole :: IO () forceConsole = modifyMVar_ globalMessageHandle $ \mh -> pure (mh { isConsole = True }) whenConsole :: String -> IO String whenConsole s = ifM (isConsole <$> getMessageHandle) ( pure s , pure "" ) -- | Shows a message while performing an action, with a colored status -- display. actionMessage :: (MonadIO m, MonadMask m, ActionResult r, ToResult r) => Desc -> m r -> m r actionMessage = actionMessage' Nothing -- | Shows a message while performing an action on a specified host, -- with a colored status display. actionMessageOn :: (MonadIO m, MonadMask m, ActionResult r, ToResult r) => HostName -> Desc -> m r -> m r actionMessageOn = actionMessage' . Just actionMessage' :: (MonadIO m, ActionResult r, ToResult r) => Maybe HostName -> Desc -> m r -> m r actionMessage' mhn desc a = do liftIO $ trace $ ActionStart mhn desc liftIO $ outputConcurrent =<< whenConsole (setTitleCode $ "propellor: " ++ desc) r <- a liftIO $ outputConcurrent . concat =<< sequence [ whenConsole $ setTitleCode "propellor: running" , showhn mhn , pure $ desc ++ " ... " , let (msg, intensity, color) = getActionResult r in colorLine intensity color msg ] liftIO $ trace $ ActionEnd mhn desc (toResult r) return r where showhn Nothing = return "" showhn (Just hn) = concat <$> sequence [ whenConsole $ setSGRCode [SetColor Foreground Dull Cyan] , pure (hn ++ " ") , whenConsole $ setSGRCode [] ] warningMessage :: MonadIO m => String -> m () warningMessage s = liftIO $ errorConcurrent =<< colorLine Vivid Magenta ("** warning: " ++ s) infoMessage :: MonadIO m => [String] -> m () infoMessage ls = liftIO $ outputConcurrent $ concatMap (++ "\n") ls -- | Displays the error message in red, and throws an exception. -- -- When used inside a property, the exception will make the current -- property fail. Propellor will continue to the next property. errorMessage :: MonadIO m => String -> m a errorMessage s = liftIO $ do errorConcurrent =<< colorLine Vivid Red ("** error: " ++ s) -- Normally this exception gets caught and is not displayed, -- and propellor continues. So it's only displayed if not -- caught, and so we say, cannot continue. error "Cannot continue!" -- | Like `errorMessage`, but throws a `StopPropellorException`, -- preventing propellor from continuing to the next property. -- -- Think twice before using this. Is the problem so bad that propellor -- cannot try to ensure other properties? If not, use `errorMessage` -- instead. stopPropellorMessage :: MonadIO m => String -> m a stopPropellorMessage s = liftIO $ do outputConcurrent =<< colorLine Vivid Red ("** fatal error: " ++ s) throwM $ StopPropellorException "Cannot continue!" colorLine :: ColorIntensity -> Color -> String -> IO String colorLine intensity color msg = concat <$> sequence [ whenConsole $ setSGRCode [SetColor Foreground intensity color] , pure msg , whenConsole $ setSGRCode [] -- Note this comes after the color is reset, so that -- the color set and reset happen in the same line. , pure "\n" ] -- | Called when all messages about properties have been printed. messagesDone :: IO () messagesDone = outputConcurrent =<< whenConsole (setTitleCode "propellor: done")