@@ -7,6 +7,7 @@
77{-# LANGUAGE FlexibleInstances #-}
88{-# LANGUAGE GADTs #-}
99{-# LANGUAGE GeneralizedNewtypeDeriving #-}
10+{-# LANGUAGE ImplicitParams #-}
1011{-# LANGUAGE MultiParamTypeClasses #-}
1112{-# LANGUAGE OverloadedStrings #-}
1213{-# LANGUAGE RankNTypes #-}
@@ -22,53 +23,39 @@
2223module Katip.Core where
2324
2425-------------------------------------------------------------------------------
25−import Control.Applicative as A
26+import Control.Applicative as A
2627import Control.AutoUpdate
2728import Control.Concurrent
28−import qualified Control.Concurrent.Async as Async
29−import Control.Concurrent.STM
30−import qualified Control.Concurrent.STM.TBQueue as BQ
31−import Control.Exception.Safe
32−import Control.Monad (unless, void, when)
29+import qualified Control.Concurrent.Async as Async
30+import qualified Control.Concurrent.Chan.Unagi.Bounded as UB
31+import Control.Monad (void)
3332import Control.Monad.Base
34−#if MIN_VERSION_base(4, 9, 0)
35−import qualified Control.Monad.Fail as MF
36−#endif
33+import Control.Monad.Catch
3734import Control.Monad.IO.Class
38−import Control.Monad.IO.Unlift
3935import Control.Monad.Trans.Class
4036import Control.Monad.Trans.Control
41−#if !MIN_VERSION_either(4, 5, 0)
4237import Control.Monad.Trans.Either
43−#endif
4438import Control.Monad.Trans.Except
4539import Control.Monad.Trans.Maybe
4640import Control.Monad.Trans.Reader
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
41+import Control.Monad.Trans.Resource
42+import Control.Monad.Trans.State
43+import Control.Monad.Trans.Writer
44+import Data.Aeson (FromJSON (..),
45+ ToJSON (..), object)
46+import qualified Data.Aeson as A
47+import Data.Foldable as FT
48+import qualified Data.HashMap.Strict as HM
6149import Data.List
62−import qualified Data.Map.Strict as M
63−import Data.Maybe (fromMaybe)
64−import Data.Semigroup as SG
50+import qualified Data.Map.Strict as M
51+import Data.Semigroup
6552import Data.String
6653import Data.String.Conv
67−import Data.Text (Text)
68−import qualified Data.Text as T
69−import qualified Data.Text.Lazy.Builder as B
54+import Data.Text (Text)
55+import qualified Data.Text as T
56+import qualified Data.Text.Lazy.Builder as B
7057import Data.Time
71−import GHC.Generics hiding (to)
58+import GHC.Generics hiding (to)
7259#if MIN_VERSION_base(4, 8, 0)
7360#if !MIN_VERSION_base(4, 9, 0)
7461import GHC.SrcLoc
@@ -76,7 +63,7 @@ import GHC.SrcLoc
7663import GHC.Stack
7764#endif
7865import Language.Haskell.TH
79−import qualified Language.Haskell.TH.Syntax as TH
66+import qualified Language.Haskell.TH.Syntax as TH
8067import Lens.Micro
8168import Lens.Micro.TH
8269import Network.HostName
@@ -103,7 +90,7 @@ readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
10390-- IsString/OverloadedStrings, so "foo" will result in Namespace
10491-- ["foo"].
10592newtype Namespace = Namespace { unNamespace :: [Text] }
106− deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,SG.Semigroup,Monoid)
93+ deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,Semigroup,Monoid)
10794
10895instance IsString Namespace where
10996 fromString s = Namespace [fromString s]
@@ -143,7 +130,7 @@ data Severity
143130-- - 'V3' implies the maximum amount of payload information.
144131-- - Anything in between is left to the discretion of the developer.
145132data Verbosity = V0 | V1 | V2 | V3
146− deriving (Eq, Ord, Show, Read, Generic, Enum, Bounded)
133+ deriving (Eq, Ord, Show, Read, Generic, Enum)
147134
148135
149136-------------------------------------------------------------------------------
@@ -184,26 +171,11 @@ instance FromJSON Severity where
184171 Just x -> return x
185172 Nothing -> fail $ "Invalid Severity " ++ toS t
186173
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−
202174
203175-------------------------------------------------------------------------------
204−-- | Log message with Builder underneath; use '<>' to concat in O(1).
176+-- | Log message with Builder unerneath; use '<>' to concat in O(1).
205177newtype LogStr = LogStr { unLogStr :: B.Builder }
206− deriving (Generic, Show, Eq)
178+ deriving (Generic, Show)
207179
208180instance IsString LogStr where
209181 fromString = LogStr . B.fromString
@@ -225,7 +197,7 @@ instance FromJSON LogStr where
225197
226198-------------------------------------------------------------------------------
227199-- | Pack any string-like thing into a 'LogStr'. This will
228−-- automatically work on 'String', 'ByteString', 'Text' and any of the
200+-- automatically work on 'String', 'ByteString, 'Text' and any of the
229201-- lazy variants.
230202logStr :: StringConv a Text => a -> LogStr
231203logStr t = LogStr (B.fromText $ toS t)
@@ -250,9 +222,7 @@ newtype ThreadIdText = ThreadIdText {
250222
251223
252224mkThreadIdText :: ThreadId -> ThreadIdText
253−mkThreadIdText = ThreadIdText . stripPrefix' "ThreadId " . T.pack . show
254− where
255− stripPrefix' pfx t = fromMaybe t (T.stripPrefix pfx t)
225+mkThreadIdText = ThreadIdText . T.pack . show
256226
257227
258228-------------------------------------------------------------------------------
@@ -272,62 +242,31 @@ data Item a = Item {
272242 } deriving (Generic, Functor)
273243makeLenses ''Item
274244
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− ]
298245
299246instance Show a => Show (Item a) where
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 <$> _itemLoc)
312− . showChar '}'
313− )
314− where
315− field n v = showString n . showString " = " . shows v . showString ", "
247+ show Item{..} = "Item {_itemApp = " ++ show _itemApp ++ ", " ++
248+ "_itemEnv = " ++ show _itemEnv ++ ", " ++
249+ "_itemSeverity = " ++ show _itemSeverity ++ ", " ++
250+ "_itemThread = " ++ show _itemThread ++ ", " ++
251+ "_itemHost = " ++ show _itemHost ++ ", " ++
252+ "_itemProcess = " ++ show _itemProcess ++ ", " ++
253+ "_itemPayload = " ++ show _itemPayload ++ ", " ++
254+ "_itemMessage = " ++ show _itemMessage ++ ", " ++
255+ "_itemTime = " ++ show _itemTime ++ ", " ++
256+ "_itemNamespace = " ++ show _itemNamespace ++ ", " ++
257+ "_itemLoc = " ++ show (LocShow <$> _itemLoc) ++ "}"
258+
316259
317260newtype LocShow = LocShow Loc
318261
319262
320263instance Show LocShow where
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 ", "
264+ show (LocShow Loc{..}) =
265+ "Loc {loc_filename = " ++ show loc_filename ++ ", " ++
266+ "loc_package = " ++ show loc_package ++ ", " ++
267+ "loc_module = " ++ show loc_module ++ ", " ++
268+ "loc_start = " ++ show loc_start ++ ", " ++
269+ "loc_end = " ++ show loc_end ++ "}"
331270
332271
333272instance ToJSON a => ToJSON (Item a) where
@@ -540,93 +479,49 @@ itemJson verb a = toJSON $ a & itemPayload %~ payloadObject verb
540479--
541480-- Scribes should always take a 'Severity' and 'Verbosity'.
542481--
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.
482+-- Severity is used to *exclude log messages* that are < the provided
483+-- Severity. For instance, if the user passes InfoS, DebugS items
484+-- should be ignored. Katip provides the 'permitItem' utility for this.
549485--
550486-- Verbosity is used to select keys from the log item's payload. Each
551487-- 'LogItem' instance describes what keys should be retained for each
552488-- Verbosity level. Use the 'payloadObject' utility for extracting the keys
553−-- that should be written.
489+-- that should be permitted.
554490--
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.
491+-- There is no built-in mechanism in katip for telling a scribe that
492+-- its time to shut down. 'unregisterScribe' merely drops it from the
493+-- 'LogEnv'. This means there are 2 ways to handle resources as a scribe:
564494--
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−
588−data Scribe = Scribe {
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'
495+-- 1. Pass in the resource when the scribe is created. Handle
496+-- allocation and release of the resource elsewhere. This is what the
497+-- Handle scribe does.
498+--
499+-- 2. Return a finalizing function that tells the scribe to shut
500+-- down. @katip-elasticsearch@'s @mkEsScribe@ returns a @IO (Scribe,
501+-- IO ())@. The finalizer will flush any queued log messages and shut
502+-- down gracefully before returning. This can be hooked into your
503+-- application's shutdown routine to ensure you never miss any log
504+-- messages on shutdown.
505+newtype Scribe = Scribe {
506+ liPush :: forall a. LogItem a => Item a -> IO ()
601507 }
602508
603509
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.
612510instance Semigroup Scribe where
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)
511+ (Scribe a) <> (Scribe b) = Scribe $ \ item -> do
512+ a item
513+ b item
619514
620515
621516instance Monoid Scribe where
622− mempty = Scribe (const (return ())) (return ()) (permitItem DebugS)
517+ mempty = Scribe $ const $ return ()
623518 mappend = (<>)
624519
625520
626521-------------------------------------------------------------------------------
627522data ScribeHandle = ScribeHandle {
628− shScribe :: Scribe
629− , shChan :: BQ.TBQueue WorkerMessage
523+ shFinalizer :: IO ()
524+ , shChan :: UB.InChan WorkerMessage
630525 }
631526
632527
@@ -638,9 +533,8 @@ data WorkerMessage where
638533
639534-------------------------------------------------------------------------------
640535-- | Should this item be logged given the user's maximum severity?
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)
536+permitItem :: Severity -> Item a -> Bool
537+permitItem sev i = _itemSeverity i >= sev
644538
645539
646540-------------------------------------------------------------------------------
@@ -665,10 +559,10 @@ makeLenses ''LogEnv
665559
666560
667561-------------------------------------------------------------------------------
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'.
562+-- | Create a reasonable default InitLogEnv. Uses an 'AutoUdate' with
563+-- the default settings as the timer. If you are concerned about
564+-- timestamp precision or event ordering in log outputs like
565+-- ElasticSearch, you should replace the timer with 'getCurrentTime'
672566initLogEnv
673567 :: Namespace
674568 -- ^ A base namespace for this application
@@ -680,15 +574,13 @@ initLogEnv an env = LogEnv
680574 <*> getProcessID
681575 <*> pure an
682576 <*> pure env
683− <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime, updateFreq = 1000 }
577+ <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
684578 <*> pure mempty
685579
686580
687581-------------------------------------------------------------------------------
688582-- | Add a scribe to the list. All future log calls will go to this
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.
583+-- scribe in addition to the others.
692584registerScribe
693585 :: Text
694586 -- ^ Name the scribe
@@ -697,104 +589,79 @@ registerScribe
697589 -> LogEnv
698590 -> IO LogEnv
699591registerScribe nm scribe ScribeSettings {..} le = do
700− queue <- atomically (BQ.newTBQueue (fromIntegral _scribeBufferSize))
701− worker <- spawnScribeWorker scribe queue
592+ (inChan, outChan) <- UB.newChan scribeBufferSize
593+ worker <- spawnScribeWorker scribe outChan
702594 let fin = do
703− atomically (BQ.writeTBQueue queue PoisonPill)
595+ UB.writeChan inChan PoisonPill
704596 -- wait for our worker to finish final write
705597 void (Async.waitCatch worker)
598+ --TODO: safe exceptions
706599 -- wait for scribe to finish final write
707− void (scribeFinalizer scribe)
600+ scribeFinalizer
708601
709− let sh = ScribeHandle (scribe { scribeFinalizer = fin }) queue
602+ let sh = ScribeHandle fin inChan
710603 return (le & logEnvScribes %~ M.insert nm sh)
711604
712605
713606-------------------------------------------------------------------------------
714−spawnScribeWorker :: Scribe -> BQ.TBQueue WorkerMessage -> IO (Async.Async ())
715−spawnScribeWorker (Scribe write _ _) queue = Async.async go
607+--TODO: should do some reasonable exception handling in the scribe, don't want to crash the loop
608+spawnScribeWorker :: Scribe -> UB.OutChan WorkerMessage -> IO (Async.Async ())
609+spawnScribeWorker (Scribe write) outChan = Async.async go
716610 where
717611 go = do
718− newCmd <- atomically (BQ.readTBQueue queue)
612+ newCmd <- UB.readChan outChan
719613 case newCmd of
720614 NewItem a -> do
721− -- Swallow any direct exceptions from the
722− -- scribe. safe-exceptions won't catch async exceptions.
723− void (tryAny (write a))
615+ write a
724616 go
725617 PoisonPill -> return ()
726618
727619
728620-------------------------------------------------------------------------------
729621data ScribeSettings = ScribeSettings {
730− _scribeBufferSize :: Int
622+ scribeFinalizer :: IO ()
623+ -- ^ Provide a *blocking* finalizer to call when your scribe is
624+ -- removed. If this is not relevant to your scribe, return () is
625+ -- fine.
626+ , scribeBufferSize :: Int
731627 }
732− deriving (Show, Eq)
733−
734−makeLenses ''ScribeSettings
735628
736629
737−-- | Reasonable defaults for a scribe. Buffer
630+--TODO: standardize on american or british spelling of finali{z,s}er
631+-- | Reasonable defaults for a scribe. No-op finalizer and a buffer
738632-- size of 4096.
739−defaultScribeSettings :: ScribeSettings
740−defaultScribeSettings = ScribeSettings 4096
633+defaultScribeSettings
634+ :: IO ()
635+ -- ^ Finalizer
636+ -> ScribeSettings
637+defaultScribeSettings fin = ScribeSettings fin 4096
741638
742639
743640-------------------------------------------------------------------------------
744−-- | Remove a scribe from the environment. This does __not__ finalize
745−-- the scribe. This mainly only makes sense to use with something like
746−-- MonadReader's @local@ function to temporarily disavow a single
747−-- logger for a block of code.
641+-- | Remove a scribe from the list. All future log calls will no
642+-- longer use this scribe. If there is a finalizer, it will be called
643+-- in a blocking manner.
748644unregisterScribe
749− :: Text
750− -- ^ Name of the scribe
751− -> LogEnv
752− -> LogEnv
753−unregisterScribe nm = logEnvScribes %~ M.delete nm
754−
755−
756−-------------------------------------------------------------------------------
757−-- | Unregister __all__ scribes. Note that this is __not__ for closing or
758−-- finalizing scribes, use 'closeScribes' for that. This mainly only
759−-- makes sense to use with something like MonadReader's @local@
760−-- function to temporarily disavow any loggers for a block of code.
761−clearScribes
762− :: LogEnv
763− -> LogEnv
764−clearScribes = logEnvScribes .~ mempty
765−
766−
767−-------------------------------------------------------------------------------
768−-- | Finalize a scribe. The scribe is removed from the environment,
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.
773−closeScribe
774645 :: Text
775646 -- ^ Name of the scribe
776647 -> LogEnv
777648 -> IO LogEnv
778−closeScribe nm le = do
779− maybe (return ()) (scribeFinalizer . shScribe) (M.lookup nm (_logEnvScribes le))
649+unregisterScribe nm le = do
650+ maybe (return ()) shFinalizer (M.lookup nm (_logEnvScribes le))
780651 return (le & logEnvScribes %~ M.delete nm)
781652
782653
783654-------------------------------------------------------------------------------
784−-- | Call this at the end of your program. This is a blocking call
785−-- that stop writing to a scribe's queue, waits for the queue to
786−-- empty, finalizes each scribe in the log environment and then
787−-- removes it. Finalizers are all run even if one of them throws, but
788−-- the exception will be re-thrown at the end.
789−closeScribes
655+-- | Unregister *all* scribes. Logs will go off into space from this
656+-- point onward until new scribes are added. Note that you could use
657+-- this with `local` if you're using a Reader based stack to
658+-- temporarily disable log output. See `katipNoLogging` for an
659+-- example.
660+clearScribes
790661 :: LogEnv
791662 -> IO LogEnv
792−closeScribes le = do
793− -- We want to run every finalizer here so we'll not save
794− -- intermediate logenvs and just clear scribes at the end.
795− let actions = [void (closeScribe k le) | k <- M.keys (_logEnvScribes le)]
796− FT.foldr finally (return ()) actions
797− return (le & logEnvScribes .~ mempty)
663+clearScribes le =
664+ foldrM unregisterScribe le (M.keys (_logEnvScribes le))
798665
799666
800667-------------------------------------------------------------------------------
@@ -807,86 +674,44 @@ closeScribes le = do
807674-- which keeps a namespace and merged context. You can write simple
808675-- functions that add additional namespacing and merges additional
809676-- context on the fly.
810−--
811−-- 'localLogEnv' was added to allow for lexically-scoped modifications
812−-- of the log env that are reverted when the supplied monad
813−-- completes. 'katipNoLogging', for example, uses this to temporarily
814−-- pause log outputs.
815677class MonadIO m => Katip m where
816678 getLogEnv :: m LogEnv
817− localLogEnv :: (LogEnv -> LogEnv) -> m a -> m a
818679
819680
820681instance Katip m => Katip (ReaderT s m) where
821682 getLogEnv = lift getLogEnv
822− localLogEnv = mapReaderT . localLogEnv
823683
824684
825−#if !MIN_VERSION_either(4, 5, 0)
826685instance Katip m => Katip (EitherT s m) where
827686 getLogEnv = lift getLogEnv
828− localLogEnv = mapEitherT . localLogEnv
829−#endif
830−
831687
832688instance Katip m => Katip (ExceptT s m) where
833689 getLogEnv = lift getLogEnv
834− localLogEnv = mapExceptT . localLogEnv
835−
836690
837691instance Katip m => Katip (MaybeT m) where
838692 getLogEnv = lift getLogEnv
839− localLogEnv = mapMaybeT . localLogEnv
840693
841694
842695instance Katip m => Katip (StateT s m) where
843696 getLogEnv = lift getLogEnv
844− localLogEnv = mapStateT . localLogEnv
845−
846−
847−instance (Katip m, Monoid w) => Katip (RWST r w s m) where
848− getLogEnv = lift getLogEnv
849− localLogEnv = mapRWST . localLogEnv
850−
851−
852−instance (Katip m, Monoid w) => Katip (Strict.RWST r w s m) where
853− getLogEnv = lift getLogEnv
854− localLogEnv = Strict.mapRWST . localLogEnv
855−
856−
857−instance Katip m => Katip (Strict.StateT s m) where
858− getLogEnv = lift getLogEnv
859− localLogEnv = Strict.mapStateT . localLogEnv
860697
861698
862699instance (Katip m, Monoid s) => Katip (WriterT s m) where
863700 getLogEnv = lift getLogEnv
864− localLogEnv = mapWriterT . localLogEnv
865−
866−
867−instance (Katip m, Monoid s) => Katip (Strict.WriterT s m) where
868− getLogEnv = lift getLogEnv
869− localLogEnv = Strict.mapWriterT . localLogEnv
870−
871701
872702instance (Katip m) => Katip (ResourceT m) where
873703 getLogEnv = lift getLogEnv
874− localLogEnv = transResourceT . localLogEnv
875704
876705
877706-------------------------------------------------------------------------------
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.
707+-- | A concrete monad you can use to run logging actions.
881708newtype KatipT m a = KatipT { unKatipT :: ReaderT LogEnv m a }
882709 deriving ( Functor, Applicative, Monad, MonadIO
883− , MonadMask, MonadCatch, MonadThrow, MonadResource, MonadTrans
884− , MonadBase b)
710+ , MonadMask, MonadCatch, MonadThrow, MonadTrans, MonadBase b)
885711
886712
887713instance MonadIO m => Katip (KatipT m) where
888714 getLogEnv = KatipT ask
889− localLogEnv f (KatipT m) = KatipT $ local f m
890715
891716
892717instance MonadTransControl KatipT where
@@ -902,21 +727,6 @@ instance (MonadBaseControl b m) => MonadBaseControl b (KatipT m) where
902727 liftBaseWith = defaultLiftBaseWith
903728 restoreM = defaultRestoreM
904729
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
920730
921731-------------------------------------------------------------------------------
922732-- | Execute 'KatipT' on a log env.
@@ -924,17 +734,6 @@ runKatipT :: LogEnv -> KatipT m a -> m a
924734runKatipT le (KatipT f) = runReaderT f le
925735
926736
927−-------------------------------------------------------------------------------
928−-- | Disable all scribes for the given monadic action, then restore
929−-- them afterwards. Works in any Katip monad.
930−katipNoLogging
931− :: ( Katip m
932− )
933− => m a
934− -> m a
935−katipNoLogging = localLogEnv (\le -> set logEnvScribes mempty le)
936−
937−
938737-------------------------------------------------------------------------------
939738-- | Log with everything, including a source code location. This is
940739-- very low level and you typically can use 'logT' in its place.
@@ -948,43 +747,20 @@ logItem
948747 -> m ()
949748logItem a ns loc sev msg = do
950749 LogEnv{..} <- getLogEnv
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))
977−
978−-------------------------------------------------------------------------------
979−tryWriteTBQueue
980− :: TBQueue a
981− -> a
982− -> STM Bool
983− -- ^ Did we write?
984−tryWriteTBQueue q a = do
985− full <- isFullTBQueue q
986− unless full (writeTBQueue q a)
987− return (not full)
750+ liftIO $ do
751+ item <- Item
752+ <$> pure _logEnvApp
753+ <*> pure _logEnvEnv
754+ <*> pure sev
755+ <*> (mkThreadIdText <$> myThreadId)
756+ <*> pure _logEnvHost
757+ <*> pure _logEnvPid
758+ <*> pure a
759+ <*> pure msg
760+ <*> _logEnvTimer
761+ <*> pure (_logEnvApp <> ns)
762+ <*> pure loc
763+ FT.forM_ (M.elems _logEnvScribes) $ \ ScribeHandle {..} -> UB.tryWriteChan shChan (NewItem item)
988764
989765
990766-------------------------------------------------------------------------------
@@ -1016,10 +792,10 @@ logException
1016792 -> Severity -- ^ Severity
1017793 -> m b -- ^ Main action being run
1018794 -> m b
1019−logException a ns sev action = action `catchAny` \e -> f e >> throwM e
795+logException a ns sev action = action `catchAll` \e -> f e >> throwM e
1020796 where
1021797 f e = logF a ns sev (msg e)
1022− msg e = ls (T.pack "An exception has occurred: ") <> showLS e
798+ msg e = ls (T.pack "An exception has occured: ") <> showLS e
1023799
1024800
1025801-------------------------------------------------------------------------------
@@ -1073,15 +849,11 @@ liftLoc (Loc a b c (d1, d2) (e1, e2)) = [|Loc
1073849-- fill the 'Maybe Loc' gap in 'logF' of this module, and relies on implicit
1074850-- callstacks when available (GHC > 7.8).
1075851#if MIN_VERSION_base(4, 8, 0)
1076−getLoc :: HasCallStack => Maybe Loc
1077−getLoc = case getCallStack callStack of
852+getLoc :: (?loc :: CallStack) => Maybe Loc
853+getLoc = case getCallStack ?loc of
1078854 [] -> Nothing
1079− xs -> Just . toLoc . head $ filter filterKatip xs
855+ xs -> Just . toLoc . last $ xs
1080856 where
1081− filterKatip :: (String, SrcLoc) -> Bool
1082− filterKatip (_, srcloc) = not $
1083− "katip-" `isPrefixOf` srcLocPackage srcloc
1084−
1085857 toLoc :: (String, SrcLoc) -> Loc
1086858 toLoc (_, l) = Loc {
1087859 loc_filename = srcLocFile l
@@ -1112,7 +884,7 @@ logT = [| \ a ns sev msg -> logItem a ns (Just $(getLocTH)) sev msg |]
1112884
1113885
1114886-------------------------------------------------------------------------------
1115−-- | 'Loc'-tagged logging using 'GHC.Stack' when available.
887+-- | 'Loc'-tagged logging using implicit-callstacks when available.
1116888--
1117889-- This function does not require template-haskell as it
1118890-- automatically uses <https://hackage.haskell.org/package/base-4.8.2.0/docs/GHC-Stack.html#v:getCallStack implicit-callstacks>
@@ -1123,7 +895,7 @@ logT = [| \ a ns sev msg -> logItem a ns (Just $(getLocTH)) sev msg |]
1123895--
1124896-- @logLoc obj mempty InfoS "Hello world"@
1125897#if MIN_VERSION_base(4, 8, 0)
1126−logLoc :: (Applicative m, LogItem a, Katip m, HasCallStack)
898+logLoc :: (Applicative m, LogItem a, Katip m, ?loc :: CallStack)
1127899#else
1128900logLoc :: (Applicative m, LogItem a, Katip m)
1129901#endif