-- | This helps to setup logging to a /file/.
module Control.Eff.LogWriter.File
( withFileLogging
, withFileLogWriter
)
where
import Control.Eff as Eff
import Control.Eff.Log
import Control.Eff.LogWriter.IO
import GHC.Stack
import Data.Text as T
import qualified System.IO as IO
import System.Directory ( canonicalizePath
, createDirectoryIfMissing
)
import System.FilePath ( takeDirectory )
import qualified Control.Exception.Safe as Safe
import qualified Control.Monad.Catch as Catch
import Control.Monad.Trans.Control ( MonadBaseControl
, liftBaseOp
)
-- | Enable logging to a file, with some 'LogMessage' fields preset
-- as described in 'withIoLogging'.
--
-- If the file or its directory does not exist, it will be created.
--
-- Example:
--
-- > exampleWithFileLogging :: IO ()
-- > exampleWithFileLogging =
-- > runLift
-- > $ withFileLogging "/var/log/my-app.log" "my-app" local7 allLogMessages
-- > $ logInfo "Oh, hi there"
--
-- To vary the 'LogWriter' use 'withIoLogging'.
withFileLogging
:: (Lifted IO e, MonadBaseControl IO (Eff e))
=> FilePath -- ^ Path to the log-file.
-> Text -- ^ The default application name to put into the 'lmAppName' field.
-> Facility -- ^ The default RFC-5424 facility to put into the 'lmFacility' field.
-> LogPredicate -- ^ The inital predicate for log messages, there are some pre-defined in "Control.Eff.Log.Message#PredefinedPredicates"
-> Eff (Logs : LogWriterReader (Lift IO) : e) a
-> Eff e a
withFileLogging fnIn a f p e =
liftBaseOp (withOpenedLogFile fnIn) (\lw -> withIoLogging lw a f p e)
-- | Enable logging to a file.
--
-- If the file or its directory does not exist, it will be created.
-- Example:
--
-- > exampleWithFileLogWriter :: IO ()
-- > exampleWithFileLogWriter =
-- > runLift
-- > $ withSomeLogging @IO
-- > $ withFileLogWriter "test.log"
-- > $ logInfo "Oh, hi there"
withFileLogWriter
:: (LogIo e, MonadBaseControl IO (Eff e))
=> FilePath -- ^ Path to the log-file.
-> Eff e b
-> Eff e b
withFileLogWriter fnIn e =
liftBaseOp (withOpenedLogFile fnIn) (`addLogWriter` e)
withOpenedLogFile :: HasCallStack => FilePath -> (LogWriter (Lift IO) -> IO a) -> IO a
withOpenedLogFile fnIn ioE = Safe.bracket
(do
fnCanon <- canonicalizePath fnIn
createDirectoryIfMissing True (takeDirectory fnCanon)
h <- IO.openFile fnCanon IO.AppendMode
IO.hSetBuffering h (IO.BlockBuffering (Just 1024))
return h
)
(\h -> Safe.try @IO @Catch.SomeException (IO.hFlush h) >> IO.hClose h)
(\h -> ioE (ioHandleLogWriter h))