@@ -7,7 +7,6 @@
77{-# LANGUAGE FlexibleInstances #-}
88{-# LANGUAGE GADTs #-}
99{-# LANGUAGE GeneralizedNewtypeDeriving #-}
10−{-# LANGUAGE ImplicitParams #-}
1110{-# LANGUAGE MultiParamTypeClasses #-}
1211{-# LANGUAGE OverloadedStrings #-}
1312{-# LANGUAGE RankNTypes #-}
@@ -23,44 +22,53 @@
2322module Katip.Core where
2423
2524-------------------------------------------------------------------------------
26−import Control.Applicative as A
25+import Control.Applicative as A
2726import Control.AutoUpdate
2827import Control.Concurrent
29−import qualified Control.Concurrent.Async as Async
28+import qualified Control.Concurrent.Async as Async
3029import Control.Concurrent.STM
31−import qualified Control.Concurrent.STM.TBQueue as BQ
30+import qualified Control.Concurrent.STM.TBQueue as BQ
3231import Control.Exception.Safe
33−import Control.Monad (unless, void)
32+import Control.Monad (unless, void, when)
3433import Control.Monad.Base
34+#if MIN_VERSION_base(4, 9, 0)
35+import qualified Control.Monad.Fail as MF
36+#endif
3537import Control.Monad.IO.Class
38+import Control.Monad.IO.Unlift
3639import Control.Monad.Trans.Class
3740import Control.Monad.Trans.Control
41+#if !MIN_VERSION_either(4, 5, 0)
3842import Control.Monad.Trans.Either
43+#endif
3944import Control.Monad.Trans.Except
4045import Control.Monad.Trans.Maybe
4146import Control.Monad.Trans.Reader
42−import Control.Monad.Trans.Resource (ResourceT, transResourceT)
43−import Control.Monad.Trans.State.Lazy (StateT, mapStateT)
44−import qualified Control.Monad.Trans.State.Strict as Strict (StateT, mapStateT)
45−import Control.Monad.Trans.Writer.Lazy (WriterT, mapWriterT)
46−import qualified Control.Monad.Trans.Writer.Strict as Strict (WriterT, mapWriterT)
47−import Control.Monad.Trans.RWS.Lazy (RWST, mapRWST)
48−import qualified Control.Monad.Trans.RWS.Strict as Strict (RWST, mapRWST)
49−import Data.Aeson (FromJSON (..), ToJSON (..),
50− object)
51−import qualified Data.Aeson as A
52−import Data.Foldable as FT
53−import qualified Data.HashMap.Strict as HM
47+import Control.Monad.Trans.Resource (MonadResource, ResourceT,
48+ transResourceT)
49+import Control.Monad.Trans.RWS.Lazy (RWST, mapRWST)
50+import qualified Control.Monad.Trans.RWS.Strict as Strict (RWST, mapRWST)
51+import Control.Monad.Trans.State.Lazy (StateT, mapStateT)
52+import qualified Control.Monad.Trans.State.Strict as Strict (StateT, mapStateT)
53+import Control.Monad.Trans.Writer.Lazy (WriterT, mapWriterT)
54+import qualified Control.Monad.Trans.Writer.Strict as Strict (WriterT,
55+ mapWriterT)
56+import Data.Aeson (FromJSON (..), ToJSON (..),
57+ object)
58+import qualified Data.Aeson as A
59+import Data.Foldable as FT
60+import qualified Data.HashMap.Strict as HM
5461import Data.List
55−import qualified Data.Map.Strict as M
56−import Data.Semigroup
62+import qualified Data.Map.Strict as M
63+import Data.Maybe (fromMaybe)
64+import Data.Semigroup as SG
5765import Data.String
5866import Data.String.Conv
59−import Data.Text (Text)
60−import qualified Data.Text as T
61−import qualified Data.Text.Lazy.Builder as B
67+import Data.Text (Text)
68+import qualified Data.Text as T
69+import qualified Data.Text.Lazy.Builder as B
6270import Data.Time
63−import GHC.Generics hiding (to)
71+import GHC.Generics hiding (to)
6472#if MIN_VERSION_base(4, 8, 0)
6573#if !MIN_VERSION_base(4, 9, 0)
6674import GHC.SrcLoc
@@ -68,7 +76,7 @@ import GHC.SrcLoc
6876import GHC.Stack
6977#endif
7078import Language.Haskell.TH
71−import qualified Language.Haskell.TH.Syntax as TH
79+import qualified Language.Haskell.TH.Syntax as TH
7280import Lens.Micro
7381import Lens.Micro.TH
7482import Network.HostName
@@ -95,7 +103,7 @@ readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
95103-- IsString/OverloadedStrings, so "foo" will result in Namespace
96104-- ["foo"].
97105newtype Namespace = Namespace { unNamespace :: [Text] }
98− deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,Semigroup,Monoid)
106+ deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,SG.Semigroup,Monoid)
99107
100108instance IsString Namespace where
101109 fromString s = Namespace [fromString s]
@@ -135,7 +143,7 @@ data Severity
135143-- - 'V3' implies the maximum amount of payload information.
136144-- - Anything in between is left to the discretion of the developer.
137145data Verbosity = V0 | V1 | V2 | V3
138− deriving (Eq, Ord, Show, Read, Generic, Enum)
146+ deriving (Eq, Ord, Show, Read, Generic, Enum, Bounded)
139147
140148
141149-------------------------------------------------------------------------------
@@ -176,11 +184,26 @@ instance FromJSON Severity where
176184 Just x -> return x
177185 Nothing -> fail $ "Invalid Severity " ++ toS t
178186
187+instance ToJSON Verbosity where
188+ toJSON s = A.String $ case s of
189+ V0 -> "V0"
190+ V1 -> "V1"
191+ V2 -> "V2"
192+ V3 -> "V3"
193+
194+instance FromJSON Verbosity where
195+ parseJSON = A.withText "Verbosity" $ \s -> case s of
196+ "V0" -> return V0
197+ "V1" -> return V1
198+ "V2" -> return V2
199+ "V3" -> return V3
200+ _ -> fail $ "Invalid Verbosity " ++ toS s
201+
179202
180203-------------------------------------------------------------------------------
181204-- | Log message with Builder underneath; use '<>' to concat in O(1).
182205newtype LogStr = LogStr { unLogStr :: B.Builder }
183− deriving (Generic, Show)
206+ deriving (Generic, Show, Eq)
184207
185208instance IsString LogStr where
186209 fromString = LogStr . B.fromString
@@ -227,7 +250,9 @@ newtype ThreadIdText = ThreadIdText {
227250
228251
229252mkThreadIdText :: ThreadId -> ThreadIdText
230−mkThreadIdText = ThreadIdText . T.pack . show
253+mkThreadIdText = ThreadIdText . stripPrefix' "ThreadId " . T.pack . show
254+ where
255+ stripPrefix' pfx t = fromMaybe t (T.stripPrefix pfx t)
231256
232257
233258-------------------------------------------------------------------------------
@@ -247,31 +272,62 @@ data Item a = Item {
247272 } deriving (Generic, Functor)
248273makeLenses ''Item
249274
275+-- Manual instance because 'Loc' has no 'Eq' and 'Show' instances in old
276+-- versions of template-haskell (< 2.10)
277+instance Eq a => Eq (Item a) where
278+ a == b = FT.and [ _itemApp a == _itemApp b
279+ , _itemEnv a == _itemEnv b
280+ , _itemSeverity a == _itemSeverity b
281+ , _itemThread a == _itemThread b
282+ , _itemHost a == _itemHost b
283+ , _itemProcess a == _itemProcess b
284+ , _itemPayload a == _itemPayload b
285+ , _itemMessage a == _itemMessage b
286+ , _itemTime a == _itemTime b
287+ , _itemNamespace a == _itemNamespace b
288+ , case (_itemLoc a, _itemLoc b) of
289+ (Nothing, Nothing) -> True
290+ (Just l1, Just l2) -> FT.and [ loc_filename l1 == loc_filename l2
291+ , loc_package l1 == loc_package l2
292+ , loc_module l1 == loc_module l2
293+ , loc_start l1 == loc_start l2
294+ , loc_end l1 == loc_end l2
295+ ]
296+ _ -> False
297+ ]
250298
251299instance Show a => Show (Item a) where
252− show Item{..} = "Item {_itemApp = " ++ show _itemApp ++ ", " ++
253− "_itemEnv = " ++ show _itemEnv ++ ", " ++
254− "_itemSeverity = " ++ show _itemSeverity ++ ", " ++
255− "_itemThread = " ++ show _itemThread ++ ", " ++
256− "_itemHost = " ++ show _itemHost ++ ", " ++
257− "_itemProcess = " ++ show _itemProcess ++ ", " ++
258− "_itemPayload = " ++ show _itemPayload ++ ", " ++
259− "_itemMessage = " ++ show _itemMessage ++ ", " ++
260− "_itemTime = " ++ show _itemTime ++ ", " ++
261− "_itemNamespace = " ++ show _itemNamespace ++ ", " ++
262− "_itemLoc = " ++ show (LocShow <$> _itemLoc) ++ "}"
263−
300+ showsPrec d Item{..} = showParen (d >= 11) ( showString "Item {"
301+ . field "_itemApp" _itemApp
302+ . field "_itemEnv" _itemEnv
303+ . field "_itemSeverity" _itemSeverity
304+ . field "_itemThread" _itemThread
305+ . field "_itemHost" _itemHost
306+ . field "_itemProcess" _itemProcess
307+ . field "_itemPayload" _itemPayload
308+ . field "_itemMessage" _itemMessage
309+ . field "_itemTime" _itemTime
310+ . field "_itemNamespace" _itemNamespace
311+ . showString "_itemLoc = " . shows (LocShow <$> _itemLoc)
312+ . showChar '}'
313+ )
314+ where
315+ field n v = showString n . showString " = " . shows v . showString ", "
264316
265317newtype LocShow = LocShow Loc
266318
267319
268320instance Show LocShow where
269− show (LocShow Loc{..}) =
270− "Loc {loc_filename = " ++ show loc_filename ++ ", " ++
271− "loc_package = " ++ show loc_package ++ ", " ++
272− "loc_module = " ++ show loc_module ++ ", " ++
273− "loc_start = " ++ show loc_start ++ ", " ++
274− "loc_end = " ++ show loc_end ++ "}"
321+ showsPrec d (LocShow Loc{..}) = showParen (d >= 11) ( showString "Loc {"
322+ . field "loc_filename" loc_filename
323+ . field "loc_package" loc_package
324+ . field "loc_module" loc_module
325+ . field "loc_start" loc_start
326+ . showString "loc_end = " . shows loc_end
327+ . showChar '}'
328+ )
329+ where
330+ field n v = showString n . showString " = " . shows v . showString ", "
275331
276332
277333instance ToJSON a => ToJSON (Item a) where
@@ -484,52 +540,93 @@ itemJson verb a = toJSON $ a & itemPayload %~ payloadObject verb
484540--
485541-- Scribes should always take a 'Severity' and 'Verbosity'.
486542--
487−-- Severity is used to *exclude log messages* that are < the provided
488−-- Severity. For instance, if the user passes InfoS, DebugS items
489−-- should be ignored. Katip provides the 'permitItem' utility for this.
543+-- Severity is used to __exclude log messages__ that are lower than
544+-- the provided Severity. For instance, if the user passes InfoS,
545+-- DebugS items should be ignored. Katip provides the 'permitItem'
546+-- utility for this. The user or the scribe may use 'permitAND' and
547+-- 'permitOR' to further customize this filtering, even dynamically if
548+-- they wish to.
490549--
491550-- Verbosity is used to select keys from the log item's payload. Each
492551-- 'LogItem' instance describes what keys should be retained for each
493552-- Verbosity level. Use the 'payloadObject' utility for extracting the keys
494−-- that should be permitted.
553+-- that should be written.
495554--
496−-- There is no built-in mechanism in katip for telling a scribe that
497−-- its time to shut down. 'unregisterScribe' merely drops it from the
498−-- 'LogEnv'. This means there are 2 ways to handle resources as a scribe:
555+-- Scribes provide a finalizer IO action ('scribeFinalizer') that is
556+-- meant to synchronously flush any remaining writes and clean up any
557+-- resources acquired when the scribe was created. Internally, katip
558+-- keeps a buffer for each scribe's writes. When 'closeScribe' or
559+-- 'closeScribes' is called, that buffer stops accepting new log
560+-- messages and after the last item in its buffer is sent to 'liPush',
561+-- calls the finalizer. Thus, when the finalizer returns, katip can
562+-- assume that all resources are cleaned up and all log messages are
563+-- durably written.
499564--
500−-- 1. Pass in the resource when the scribe is created. Handle
501−-- allocation and release of the resource elsewhere. This is what the
502−-- Handle scribe does.
503−--
504−-- 2. Return a finalizing function that tells the scribe to shut
505−-- down. @katip-elasticsearch@'s @mkEsScribe@ returns an @IO (Scribe,
506−-- IO ())@. The finalizer will flush any queued log messages and shut
507−-- down gracefully before returning. This can be hooked into your
508−-- application's shutdown routine to ensure you never miss any log
509−-- messages on shutdown.
565+-- While katip internally buffers messages per 'ScribeSettings', it
566+-- sends them one at a time to the scribe. Depending on the scribe
567+-- itself, it may make sense for that scribe to keep its own internal
568+-- buffer to batch-send logs if writing items one at a time is not
569+-- efficient. The scribe implementer must be sure that on
570+-- finalization, all writes are committed synchronously.
571+
572+-- | Signature of a function passed to `Scribe` constructor and
573+-- mkScribe* functions that decides which messages to be
574+-- logged. Typically filters based on 'Severity', but can be
575+-- combined with other, custom logic with 'permitAND' and 'permitOR'
576+type PermitFunc = forall a. Item a -> IO Bool
577+
578+
579+-- | AND together 2 permit functions
580+permitAND :: PermitFunc -> PermitFunc -> PermitFunc
581+permitAND f1 f2 = \a -> liftA2 (&&) (f1 a) (f2 a)
582+
583+-- | OR together 2 permit functions
584+permitOR :: PermitFunc -> PermitFunc -> PermitFunc
585+permitOR f1 f2 = \a -> liftA2 (||) (f1 a) (f2 a)
586+
587+
510588data Scribe = Scribe {
511− liPush :: forall a. LogItem a => Item a -> IO ()
512− , scribeFinalizer :: IO ()
513− -- ^ Provide a *blocking* finalizer to call when your scribe is
514− -- removed. If this is not relevant to your scribe, return () is
515− -- fine.
589+ liPush :: forall a. LogItem a => Item a -> IO ()
590+ -- ^ How do we write an item to the scribe's output?
591+ , scribeFinalizer :: IO ()
592+ -- ^ Provide a __blocking__ finalizer to call when your scribe is
593+ -- removed. All pending writes should be flushed synchronously. If
594+ -- this is not relevant to your scribe, return () is fine.
595+ , scribePermitItem :: PermitFunc
596+ -- ^ Provide a filtering function to allow the item to be logged,
597+ -- or not. It can check Severity or some string in item's
598+ -- body. The initial value of this is usually created from
599+ -- 'permitItem'. Scribes and users can customize this by ANDing
600+ -- or ORing onto the default with 'permitAND' or 'permitOR'
516601 }
517602
518603
604+whenM :: Monad m => m Bool -> m () -> m ()
605+whenM mbool = (>>=) mbool . flip when
606+
607+
608+-- | Combine two scribes. Publishes to the left scribe if the left
609+-- would permit the item and to the right scribe if the right would
610+-- permit the item. Finalizers are called in sequence from left to
611+-- right.
519612instance Semigroup Scribe where
520− (Scribe pushA finA) <> (Scribe pushB finB) =
521− Scribe (\item -> pushA item >> pushB item) (finA `finally` finB)
613+ (Scribe pushA finA permitA) <> (Scribe pushB finB permitB) =
614+ Scribe (\item -> whenM (permitA item) (pushA item)
615+ >> whenM (permitB item) (pushB item)
616+ )
617+ (finA `finally` finB)
618+ (permitOR permitA permitB)
522619
523620
524621instance Monoid Scribe where
525− mempty = Scribe (const (return ())) (return ())
622+ mempty = Scribe (const (return ())) (return ()) (permitItem DebugS)
526623 mappend = (<>)
527624
528625
529626-------------------------------------------------------------------------------
530627data ScribeHandle = ScribeHandle {
531628 shScribe :: Scribe
532− , shChan :: BQ.TBQueue WorkerMessage
629+ , shChan :: BQ.TBQueue WorkerMessage
533630 }
534631
535632
@@ -541,8 +638,9 @@ data WorkerMessage where
541638
542639-------------------------------------------------------------------------------
543640-- | Should this item be logged given the user's maximum severity?
544−permitItem :: Severity -> Item a -> Bool
545−permitItem sev i = _itemSeverity i >= sev
641+-- Most new scribes will use this as a base for their 'PermitFunc'
642+permitItem :: Monad m => Severity -> Item a -> m Bool
643+permitItem sev item = return (_itemSeverity item >= sev)
546644
547645
548646-------------------------------------------------------------------------------
@@ -567,10 +665,10 @@ makeLenses ''LogEnv
567665
568666
569667-------------------------------------------------------------------------------
570−-- | Create a reasonable default InitLogEnv. Uses an 'AutoUdate' with
571−-- the default settings as the timer. If you are concerned about
572−-- timestamp precision or event ordering in log outputs like
573−-- ElasticSearch, you should replace the timer with 'getCurrentTime'
668+-- | Create a reasonable default InitLogEnv. Uses an 'AutoUpdate' which
669+-- updates the timer every 1ms. If you need even more timestamp
670+-- precision at the cost of performance, consider setting
671+-- '_logEnvTimer' with 'getCurrentTime'.
574672initLogEnv
575673 :: Namespace
576674 -- ^ A base namespace for this application
@@ -582,13 +680,15 @@ initLogEnv an env = LogEnv
582680 <*> getProcessID
583681 <*> pure an
584682 <*> pure env
585− <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
683+ <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime, updateFreq = 1000 }
586684 <*> pure mempty
587685
588686
589687-------------------------------------------------------------------------------
590688-- | Add a scribe to the list. All future log calls will go to this
591−-- scribe in addition to the others.
689+-- scribe in addition to the others. Writes will be buffered per the
690+-- ScribeSettings to prevent slow scribes from slowing down
691+-- logging. Writes will be dropped if the buffer fills.
592692registerScribe
593693 :: Text
594694 -- ^ Name the scribe
@@ -597,7 +697,7 @@ registerScribe
597697 -> LogEnv
598698 -> IO LogEnv
599699registerScribe nm scribe ScribeSettings {..} le = do
600− queue <- atomically (BQ.newTBQueue _scribeBufferSize)
700+ queue <- atomically (BQ.newTBQueue (fromIntegral _scribeBufferSize))
601701 worker <- spawnScribeWorker scribe queue
602702 let fin = do
603703 atomically (BQ.writeTBQueue queue PoisonPill)
@@ -612,7 +712,7 @@ registerScribe nm scribe ScribeSettings {..} le = do
612712
613713-------------------------------------------------------------------------------
614714spawnScribeWorker :: Scribe -> BQ.TBQueue WorkerMessage -> IO (Async.Async ())
615−spawnScribeWorker (Scribe write _) queue = Async.async go
715+spawnScribeWorker (Scribe write _ _) queue = Async.async go
616716 where
617717 go = do
618718 newCmd <- atomically (BQ.readTBQueue queue)
@@ -629,6 +729,7 @@ spawnScribeWorker (Scribe write _) queue = Async.async go
629729data ScribeSettings = ScribeSettings {
630730 _scribeBufferSize :: Int
631731 }
732+ deriving (Show, Eq)
632733
633734makeLenses ''ScribeSettings
634735
@@ -640,7 +741,7 @@ defaultScribeSettings = ScribeSettings 4096
640741
641742
642743-------------------------------------------------------------------------------
643−-- | Remove a scribe from the environment. This does *not* finalize
744+-- | Remove a scribe from the environment. This does __not__ finalize
644745-- the scribe. This mainly only makes sense to use with something like
645746-- MonadReader's @local@ function to temporarily disavow a single
646747-- logger for a block of code.
@@ -653,7 +754,7 @@ unregisterScribe nm = logEnvScribes %~ M.delete nm
653754
654755
655756-------------------------------------------------------------------------------
656−-- | Unregister *all* scribes. Note that this is *not* for closing or
757+-- | Unregister __all__ scribes. Note that this is __not__ for closing or
657758-- finalizing scribes, use 'closeScribes' for that. This mainly only
658759-- makes sense to use with something like MonadReader's @local@
659760-- function to temporarily disavow any loggers for a block of code.
@@ -665,9 +766,10 @@ clearScribes = logEnvScribes .~ mempty
665766
666767-------------------------------------------------------------------------------
667768-- | Finalize a scribe. The scribe is removed from the environment,
668−-- its finalizer is called and it can never be written to again. Note
669−-- that this will throw any exceptions yoru finalizer will throw, and
670−-- that LogEnv is immutable, so it will not be removed in that case.
769+-- its finalizer is called so that it can never be written to again
770+-- and all pending writes are flushed. Note that this will throw any
771+-- exceptions yoru finalizer will throw, and that LogEnv is immutable,
772+-- so it will not be removed in that case.
671773closeScribe
672774 :: Text
673775 -- ^ Name of the scribe
@@ -720,9 +822,11 @@ instance Katip m => Katip (ReaderT s m) where
720822 localLogEnv = mapReaderT . localLogEnv
721823
722824
825+#if !MIN_VERSION_either(4, 5, 0)
723826instance Katip m => Katip (EitherT s m) where
724827 getLogEnv = lift getLogEnv
725828 localLogEnv = mapEitherT . localLogEnv
829+#endif
726830
727831
728832instance Katip m => Katip (ExceptT s m) where
@@ -771,10 +875,13 @@ instance (Katip m) => Katip (ResourceT m) where
771875
772876
773877-------------------------------------------------------------------------------
774−-- | A concrete monad you can use to run logging actions.
878+-- | A concrete monad you can use to run logging actions. Use this if
879+-- you prefer an explicit monad transformer stack and adding layers as
880+-- opposed to implementing 'Katip' for your monad.
775881newtype KatipT m a = KatipT { unKatipT :: ReaderT LogEnv m a }
776882 deriving ( Functor, Applicative, Monad, MonadIO
777− , MonadMask, MonadCatch, MonadThrow, MonadTrans, MonadBase b)
883+ , MonadMask, MonadCatch, MonadThrow, MonadResource, MonadTrans
884+ , MonadBase b)
778885
779886
780887instance MonadIO m => Katip (KatipT m) where
@@ -795,6 +902,21 @@ instance (MonadBaseControl b m) => MonadBaseControl b (KatipT m) where
795902 liftBaseWith = defaultLiftBaseWith
796903 restoreM = defaultRestoreM
797904
905+instance MonadUnliftIO m => MonadUnliftIO (KatipT m) where
906+#if MIN_VERSION_unliftio_core(0, 2, 0)
907+ withRunInIO inner = KatipT $ ReaderT $ \le -> withRunInIO $ \run ->
908+ inner (run . runKatipT le)
909+#else
910+ askUnliftIO = KatipT $
911+ withUnliftIO $ \u ->
912+ pure (UnliftIO (unliftIO u . unKatipT))
913+#endif
914+
915+#if MIN_VERSION_base(4, 9, 0)
916+instance MF.MonadFail m => MF.MonadFail (KatipT m) where
917+ fail msg = lift (MF.fail msg)
918+ {-# INLINE fail #-}
919+#endif
798920
799921-------------------------------------------------------------------------------
800922-- | Execute 'KatipT' on a log env.
@@ -826,21 +948,32 @@ logItem
826948 -> m ()
827949logItem a ns loc sev msg = do
828950 LogEnv{..} <- getLogEnv
829− liftIO $ do
830− item <- Item
831− <$> pure _logEnvApp
832− <*> pure _logEnvEnv
833− <*> pure sev
834− <*> (mkThreadIdText <$> myThreadId)
835− <*> pure _logEnvHost
836− <*> pure _logEnvPid
837− <*> pure a
838− <*> pure msg
839− <*> _logEnvTimer
840− <*> pure (_logEnvApp <> ns)
841− <*> pure loc
842− FT.forM_ (M.elems _logEnvScribes) $ \ ScribeHandle {..} -> atomically (tryWriteTBQueue shChan (NewItem item))
843−
951+ logKatipItem =<< liftIO
952+ (Item <$> pure _logEnvApp
953+ <*> pure _logEnvEnv
954+ <*> pure sev
955+ <*> (mkThreadIdText <$> myThreadId)
956+ <*> pure _logEnvHost
957+ <*> pure _logEnvPid
958+ <*> pure a
959+ <*> pure msg
960+ <*> _logEnvTimer
961+ <*> pure (_logEnvApp <> ns)
962+ <*> pure loc)
963+
964+-- | Log already constructed 'Item'. This is the lowest level function that other log*
965+-- functions use.
966+-- It can be useful when implementing centralised logging services.
967+logKatipItem
968+ :: (A.Applicative m, LogItem a, Katip m)
969+ => Item a
970+ -> m ()
971+logKatipItem item = do
972+ LogEnv{..} <- getLogEnv
973+ liftIO $
974+ FT.forM_ (M.elems _logEnvScribes) $ \ ScribeHandle {..} -> do
975+ whenM (scribePermitItem shScribe item) $
976+ void $ atomically (tryWriteTBQueue shChan (NewItem item))
844977
845978-------------------------------------------------------------------------------
846979tryWriteTBQueue
@@ -853,6 +986,7 @@ tryWriteTBQueue q a = do
853986 unless full (writeTBQueue q a)
854987 return (not full)
855988
989+
856990-------------------------------------------------------------------------------
857991-- | Log with full context, but without any code location.
858992logF
@@ -885,7 +1019,7 @@ logException
8851019logException a ns sev action = action `catchAny` \e -> f e >> throwM e
8861020 where
8871021 f e = logF a ns sev (msg e)
888− msg e = ls (T.pack "An exception has occured: ") <> showLS e
1022+ msg e = ls (T.pack "An exception has occurred: ") <> showLS e
8891023
8901024
8911025-------------------------------------------------------------------------------
@@ -939,11 +1073,15 @@ liftLoc (Loc a b c (d1, d2) (e1, e2)) = [|Loc
9391073-- fill the 'Maybe Loc' gap in 'logF' of this module, and relies on implicit
9401074-- callstacks when available (GHC > 7.8).
9411075#if MIN_VERSION_base(4, 8, 0)
942−getLoc :: (?loc :: CallStack) => Maybe Loc
943−getLoc = case getCallStack ?loc of
1076+getLoc :: HasCallStack => Maybe Loc
1077+getLoc = case getCallStack callStack of
9441078 [] -> Nothing
945− xs -> Just . toLoc . last $ xs
1079+ xs -> Just . toLoc . head $ filter filterKatip xs
9461080 where
1081+ filterKatip :: (String, SrcLoc) -> Bool
1082+ filterKatip (_, srcloc) = not $
1083+ "katip-" `isPrefixOf` srcLocPackage srcloc
1084+
9471085 toLoc :: (String, SrcLoc) -> Loc
9481086 toLoc (_, l) = Loc {
9491087 loc_filename = srcLocFile l
@@ -974,7 +1112,7 @@ logT = [| \ a ns sev msg -> logItem a ns (Just $(getLocTH)) sev msg |]
9741112
9751113
9761114-------------------------------------------------------------------------------
977−-- | 'Loc'-tagged logging using implicit-callstacks when available.
1115+-- | 'Loc'-tagged logging using 'GHC.Stack' when available.
9781116--
9791117-- This function does not require template-haskell as it
9801118-- automatically uses <https://hackage.haskell.org/package/base-4.8.2.0/docs/GHC-Stack.html#v:getCallStack implicit-callstacks>
@@ -985,7 +1123,7 @@ logT = [| \ a ns sev msg -> logItem a ns (Just $(getLocTH)) sev msg |]
9851123--
9861124-- @logLoc obj mempty InfoS "Hello world"@
9871125#if MIN_VERSION_base(4, 8, 0)
988−logLoc :: (Applicative m, LogItem a, Katip m, ?loc :: CallStack)
1126+logLoc :: (Applicative m, LogItem a, Katip m, HasCallStack)
9891127#else
9901128logLoc :: (Applicative m, LogItem a, Katip m)
9911129#endif