@@ -1,11 +1,8 @@
1−{-# LANGUAGE CPP #-}
2−{-# LANGUAGE DefaultSignatures #-}
31{-# LANGUAGE DeriveFunctor #-}
42{-# LANGUAGE DeriveGeneric #-}
53{-# LANGUAGE ExistentialQuantification #-}
64{-# LANGUAGE FlexibleContexts #-}
75{-# LANGUAGE FlexibleInstances #-}
8−{-# LANGUAGE GADTs #-}
96{-# LANGUAGE GeneralizedNewtypeDeriving #-}
107{-# LANGUAGE MultiParamTypeClasses #-}
118{-# LANGUAGE OverloadedStrings #-}
@@ -14,86 +11,55 @@
1411{-# LANGUAGE TemplateHaskell #-}
1512{-# LANGUAGE TypeFamilies #-}
1613{-# LANGUAGE UndecidableInstances #-}
17−#if MIN_VERSION_base(4, 9, 0)
18−{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
19−#endif
2014-- | This module is not meant to be imported directly and may contain
2115-- internal mechanisms that will change without notice.
2216module Katip.Core where
2317
2418-------------------------------------------------------------------------------
25−import Control.Applicative as A
19+import Control.Applicative as A
2620import Control.AutoUpdate
2721import 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)
3322import Control.Monad.Base
34−#if MIN_VERSION_base(4, 9, 0)
35−import qualified Control.Monad.Fail as MF
36−#endif
23+import Control.Monad.Catch
3724import Control.Monad.IO.Class
38−import Control.Monad.IO.Unlift
3925import Control.Monad.Trans.Class
4026import Control.Monad.Trans.Control
41−#if !MIN_VERSION_either(4, 5, 0)
4227import Control.Monad.Trans.Either
43−#endif
4428import Control.Monad.Trans.Except
4529import Control.Monad.Trans.Maybe
4630import 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
31+import Control.Monad.Trans.Resource
32+import Control.Monad.Trans.State
33+import Control.Monad.Trans.Writer
34+import Data.Aeson (FromJSON (..), ToJSON (..),
35+ object)
36+import qualified Data.Aeson as A
37+import Data.Foldable as FT
38+import qualified Data.HashMap.Strict as HM
6139import Data.List
62−import qualified Data.Map.Strict as M
63−import Data.Maybe (fromMaybe)
64−import Data.Semigroup as SG
40+import qualified Data.Map.Strict as M
41+import Data.Monoid
6542import Data.String
6643import Data.String.Conv
67−import Data.Text (Text)
68−import qualified Data.Text as T
69−import qualified Data.Text.Lazy.Builder as B
44+import Data.Text (Text)
45+import qualified Data.Text as T
46+import qualified Data.Text.Lazy.Builder as B
7047import Data.Time
71−import GHC.Generics hiding (to)
72−#if MIN_VERSION_base(4, 8, 0)
73−#if !MIN_VERSION_base(4, 9, 0)
74−import GHC.SrcLoc
75−#endif
76−import GHC.Stack
77−#endif
48+import GHC.Generics hiding (to)
7849import Language.Haskell.TH
79−import qualified Language.Haskell.TH.Syntax as TH
50+import qualified Language.Haskell.TH.Syntax as TH
8051import Lens.Micro
8152import Lens.Micro.TH
8253import Network.HostName
83−#if mingw32_HOST_OS
84−import Katip.Compat
85−#else
8654import System.Posix
87−#endif
88−
8955-------------------------------------------------------------------------------
9056
9157
9258readMay :: Read a => String -> Maybe a
9359readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
9460 [x] -> Just x
95− [] -> Nothing -- no parse
96− _ -> Nothing -- Ambiguous parse
61+ [] -> Nothing -- no parse
62+ _ -> Nothing -- Ambiguous parse
9763
9864
9965-------------------------------------------------------------------------------
@@ -103,7 +69,7 @@ readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
10369-- IsString/OverloadedStrings, so "foo" will result in Namespace
10470-- ["foo"].
10571newtype Namespace = Namespace { unNamespace :: [Text] }
106− deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,SG.Semigroup,Monoid)
72+ deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,Monoid)
10773
10874instance IsString Namespace where
10975 fromString s = Namespace [fromString s]
@@ -143,35 +109,33 @@ data Severity
143109-- - 'V3' implies the maximum amount of payload information.
144110-- - Anything in between is left to the discretion of the developer.
145111data Verbosity = V0 | V1 | V2 | V3
146− deriving (Eq, Ord, Show, Read, Generic, Enum, Bounded)
112+ deriving (Eq, Ord, Show, Read, Generic, Enum)
147113
148114
149115-------------------------------------------------------------------------------
150116renderSeverity :: Severity -> Text
151117renderSeverity s = case s of
152− DebugS -> "Debug"
153− InfoS -> "Info"
154− NoticeS -> "Notice"
155− WarningS -> "Warning"
156− ErrorS -> "Error"
157− CriticalS -> "Critical"
158− AlertS -> "Alert"
118+ DebugS -> "Debug"
119+ InfoS -> "Info"
120+ NoticeS -> "Notice"
121+ WarningS -> "Warning"
122+ ErrorS -> "Error"
123+ CriticalS -> "Critical"
124+ AlertS -> "Alert"
159125 EmergencyS -> "Emergency"
160126
161127
162128-------------------------------------------------------------------------------
163129textToSeverity :: Text -> Maybe Severity
164−textToSeverity = go . T.toLower
165− where
166− go "debug" = Just DebugS
167− go "info" = Just InfoS
168− go "notice" = Just NoticeS
169− go "warning" = Just WarningS
170− go "error" = Just ErrorS
171− go "critical" = Just CriticalS
172− go "alert" = Just AlertS
173− go "emergency" = Just EmergencyS
174− go _ = Nothing
130+textToSeverity "Debug" = Just DebugS
131+textToSeverity "Info" = Just InfoS
132+textToSeverity "Notice" = Just NoticeS
133+textToSeverity "Warning" = Just WarningS
134+textToSeverity "Error" = Just ErrorS
135+textToSeverity "Critical" = Just CriticalS
136+textToSeverity "Alert" = Just AlertS
137+textToSeverity "Emergency" = Just EmergencyS
138+textToSeverity _ = Nothing
175139
176140
177141instance ToJSON Severity where
@@ -181,43 +145,22 @@ instance FromJSON Severity where
181145 parseJSON = A.withText "Severity" parseSeverity
182146 where
183147 parseSeverity t = case textToSeverity t of
184− Just x -> return x
148+ Just x -> return x
185149 Nothing -> fail $ "Invalid Severity " ++ toS t
186150
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−
202151
203152-------------------------------------------------------------------------------
204−-- | Log message with Builder underneath; use '<>' to concat in O(1).
153+-- | Log message with Builder unerneath; use '<>' to concat in O(1).
205154newtype LogStr = LogStr { unLogStr :: B.Builder }
206− deriving (Generic, Show, Eq)
155+ deriving (Generic, Show)
207156
208157instance IsString LogStr where
209158 fromString = LogStr . B.fromString
210159
211−
212−instance Semigroup LogStr where
213− (LogStr a) <> (LogStr b) = LogStr (a <> b)
214−
215−
216160instance Monoid LogStr where
217− mappend = (<>)
161+ mappend (LogStr a) (LogStr b) = LogStr (a `mappend` b)
218162 mempty = LogStr mempty
219163
220−
221164instance FromJSON LogStr where
222165 parseJSON = A.withText "LogStr" parseLogStr
223166 where
@@ -225,20 +168,20 @@ instance FromJSON LogStr where
225168
226169-------------------------------------------------------------------------------
227170-- | Pack any string-like thing into a 'LogStr'. This will
228−-- automatically work on 'String', 'ByteString', 'Text' and any of the
171+-- automatically work on 'String', 'ByteString, 'Text' and any of the
229172-- lazy variants.
230173logStr :: StringConv a Text => a -> LogStr
231174logStr t = LogStr (B.fromText $ toS t)
232175
233176
234177-------------------------------------------------------------------------------
235−-- | Shorthand for 'logStr'
178+-- | Shorthand for 'logMsg'
236179ls :: StringConv a Text => a -> LogStr
237180ls = logStr
238181
239182
240183-------------------------------------------------------------------------------
241−-- | Convert any showable type into a 'LogStr'.
184+-- | Convert any showable type into a LogStr.
242185showLS :: Show a => a -> LogStr
243186showLS = ls . show
244187
@@ -250,9 +193,7 @@ newtype ThreadIdText = ThreadIdText {
250193
251194
252195mkThreadIdText :: ThreadId -> ThreadIdText
253−mkThreadIdText = ThreadIdText . stripPrefix' "ThreadId " . T.pack . show
254− where
255− stripPrefix' pfx t = fromMaybe t (T.stripPrefix pfx t)
196+mkThreadIdText = ThreadIdText . T.pack . show
256197
257198
258199-------------------------------------------------------------------------------
@@ -272,62 +213,31 @@ data Item a = Item {
272213 } deriving (Generic, Functor)
273214makeLenses ''Item
274215
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− ]
298216
299217instance 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 <$> _itemLoc)
312− . showChar '}'
313− )
314− where
315− field n v = showString n . showString " = " . shows v . showString ", "
218+ show Item{..} = "Item {_itemApp = " ++ show _itemApp ++ ", " ++
219+ "_itemEnv = " ++ show _itemEnv ++ ", " ++
220+ "_itemSeverity = " ++ show _itemSeverity ++ ", " ++
221+ "_itemThread = " ++ show _itemThread ++ ", " ++
222+ "_itemHost = " ++ show _itemHost ++ ", " ++
223+ "_itemProcess = " ++ show _itemProcess ++ ", " ++
224+ "_itemPayload = " ++ show _itemPayload ++ ", " ++
225+ "_itemMessage = " ++ show _itemMessage ++ ", " ++
226+ "_itemTime = " ++ show _itemTime ++ ", " ++
227+ "_itemNamespace = " ++ show _itemNamespace ++ ", " ++
228+ "_itemLoc = " ++ show (LocShow <$> _itemLoc) ++ "}"
229+
316230
317231newtype LocShow = LocShow Loc
318232
319233
320234instance 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 ", "
235+ show (LocShow Loc{..}) =
236+ "Loc {loc_filename = " ++ show loc_filename ++ ", " ++
237+ "loc_package = " ++ show loc_package ++ ", " ++
238+ "loc_module = " ++ show loc_module ++ ", " ++
239+ "loc_start = " ++ show loc_start ++ ", " ++
240+ "loc_end = " ++ show loc_end ++ "}"
331241
332242
333243instance ToJSON a => ToJSON (Item a) where
@@ -408,7 +318,7 @@ instance FromJSON ProcessIDJs where
408318 parseJSON = A.withText "ProcessID" parseProcessID
409319 where
410320 parseProcessID t = case textToProcessID t of
411− Just p -> return $ ProcessIDJs p
321+ Just p -> return $ ProcessIDJs p
412322 Nothing -> fail $ "Invalid ProcessIDJs " ++ toS t
413323
414324
@@ -419,15 +329,11 @@ data PayloadSelection
419329 | SomeKeys [Text]
420330 deriving (Show, Eq)
421331
422−instance Semigroup PayloadSelection where
423− AllKeys <> _ = AllKeys
424− _ <> AllKeys = AllKeys
425− SomeKeys as <> SomeKeys bs = SomeKeys (as <> bs)
426−
427−
428332instance Monoid PayloadSelection where
429333 mempty = SomeKeys []
430− mappend = (<>)
334+ mappend AllKeys _ = AllKeys
335+ mappend _ AllKeys = AllKeys
336+ mappend (SomeKeys as) (SomeKeys bs) = SomeKeys (as++bs)
431337
432338
433339-------------------------------------------------------------------------------
@@ -440,12 +346,11 @@ instance Monoid PayloadSelection where
440346-- a ToJSON instance like:
441347--
442348-- > instance ToObject Foo
443−class ToObject a where
349+class ToJSON a => ToObject a where
444350 toObject :: a -> A.Object
445− default toObject :: ToJSON a => a -> A.Object
446351 toObject v = case toJSON v of
447352 A.Object o -> o
448− _ -> mempty
353+ _ -> mempty
449354
450355instance ToObject ()
451356instance ToObject A.Object
@@ -491,22 +396,15 @@ instance ToJSON SimpleLogPayload where
491396 toJSON (SimpleLogPayload as) = object $ map go as
492397 where go (k, AnyLogPayload v) = k A..= v
493398
494−
495399instance ToObject SimpleLogPayload
496400
497−
498401instance LogItem SimpleLogPayload where
499402 payloadKeys V0 _ = SomeKeys []
500− payloadKeys _ _ = AllKeys
501−
502−
503−instance Semigroup SimpleLogPayload where
504− SimpleLogPayload a <> SimpleLogPayload b = SimpleLogPayload (a <> b)
505−
403+ payloadKeys _ _ = AllKeys
506404
507405instance Monoid SimpleLogPayload where
508406 mempty = SimpleLogPayload []
509− mappend = (<>)
407+ SimpleLogPayload a `mappend` SimpleLogPayload b = SimpleLogPayload (a `mappend` b)
510408
511409
512410-------------------------------------------------------------------------------
@@ -520,7 +418,7 @@ sl a b = SimpleLogPayload [(a, AnyLogPayload b)]
520418-- automatically bubble higher verbosity levels to lower ones.
521419payloadObject :: LogItem a => Verbosity -> a -> A.Object
522420payloadObject verb a = case FT.foldMap (flip payloadKeys a) [(V0)..verb] of
523− AllKeys -> toObject a
421+ AllKeys -> toObject a
524422 SomeKeys ks -> HM.filterWithKey (\ k _ -> k `FT.elem` ks) $ toObject a
525423
526424
@@ -540,135 +438,67 @@ itemJson verb a = toJSON $ a & itemPayload %~ payloadObject verb
540438--
541439-- Scribes should always take a 'Severity' and 'Verbosity'.
542440--
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.
441+-- Severity is used to *exclude log messages* that are < the provided
442+-- Severity. For instance, if the user passes InfoS, DebugS items
443+-- should be ignored. Katip provides the 'permitItem' utility for this.
549444--
550445-- Verbosity is used to select keys from the log item's payload. Each
551446-- 'LogItem' instance describes what keys should be retained for each
552447-- Verbosity level. Use the 'payloadObject' utility for extracting the keys
553−-- that should be written.
448+-- that should be permitted.
554449--
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.
450+-- There is no built-in mechanism in katip for telling a scribe that
451+-- its time to shut down. 'unregisterScribe' merely drops it from the
452+-- 'LogEnv'. This means there are 2 ways to handle resources as a scribe:
564453--
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−
454+-- 1. Pass in the resource when the scribe is created. Handle
455+-- allocation and release of the resource elsewhere. This is what the
456+-- Handle scribe does.
457+--
458+-- 2. Return a finalizing function that tells the scribe to shut
459+-- down. @katip-elasticsearch@'s @mkEsScribe@ returns a @IO (Scribe,
460+-- IO ())@. The finalizer will flush any queued log messages and shut
461+-- down gracefully before returning. This can be hooked into your
462+-- application's shutdown routine to ensure you never miss any log
463+-- messages on shutdown.
588464data 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'
601− }
602−
603−
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.
612−instance 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)
619−
620−
621−instance Monoid Scribe where
622− mempty = Scribe (const (return ())) (return ()) (permitItem DebugS)
623− mappend = (<>)
624−
625−
626−-------------------------------------------------------------------------------
627−data ScribeHandle = ScribeHandle {
628− shScribe :: Scribe
629− , shChan :: BQ.TBQueue WorkerMessage
465+ liPush :: forall a. LogItem a => Item a -> IO ()
630466 }
631467
632468
633−-------------------------------------------------------------------------------
634−data WorkerMessage where
635− NewItem :: LogItem a => Item a -> WorkerMessage
636− PoisonPill :: WorkerMessage
469+instance Monoid Scribe where
470+ mempty = Scribe $ const $ return ()
471+ mappend (Scribe a) (Scribe b) = Scribe $ \ item -> do
472+ a item
473+ b item
637474
638475
639476-------------------------------------------------------------------------------
640477-- | 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)
478+permitItem :: Severity -> Item a -> Bool
479+permitItem sev i = _itemSeverity i >= sev
644480
645481
646482-------------------------------------------------------------------------------
647483data LogEnv = LogEnv {
648484 _logEnvHost :: HostName
649485 , _logEnvPid :: ProcessID
650− , _logEnvApp :: Namespace
651− -- ^ Name of application. This will typically never change. This
652− -- field gets prepended to the namespace of your individual log
653− -- messages. For example, if your app is MyApp and you write a log
654− -- using "logItem" and the namespace "WebServer", the final
655− -- namespace will be "MyApp.WebServer"
486+ , _logEnvNs :: Namespace
656487 , _logEnvEnv :: Environment
657488 , _logEnvTimer :: IO UTCTime
658489 -- ^ Action to fetch the timestamp. You can use something like
659490 -- 'AutoUpdate' for high volume logs but note that this may cause
660− -- some output forms to display logs out of order. Alternatively,
661− -- you could just use 'getCurrentTime'.
662− , _logEnvScribes :: M.Map Text ScribeHandle
491+ -- some output forms to display logs out of order.
492+ , _logEnvScribes :: M.Map Text Scribe
663493 }
664494makeLenses ''LogEnv
665495
666496
667497-------------------------------------------------------------------------------
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'.
498+-- | Create a reasonable default InitLogEnv. Uses an 'AutoUdate' with
499+-- the default settings as the timer. If you are concerned about
500+-- timestamp precision or event ordering in log outputs like
501+-- ElasticSearch, you should replace the timer with 'getCurrentTime'
672502initLogEnv
673503 :: Namespace
674504 -- ^ A base namespace for this application
@@ -680,84 +510,36 @@ initLogEnv an env = LogEnv
680510 <*> getProcessID
681511 <*> pure an
682512 <*> pure env
683− <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime, updateFreq = 1000 }
513+ <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
684514 <*> pure mempty
685515
686516
687517-------------------------------------------------------------------------------
688518-- | 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.
519+-- scribe in addition to the others.
692520registerScribe
693521 :: Text
694522 -- ^ Name the scribe
695523 -> Scribe
696− -> ScribeSettings
697524 -> LogEnv
698− -> IO LogEnv
699−registerScribe nm scribe ScribeSettings {..} le = do
700− queue <- atomically (BQ.newTBQueue (fromIntegral _scribeBufferSize))
701− worker <- spawnScribeWorker scribe queue
702− let fin = do
703− atomically (BQ.writeTBQueue queue PoisonPill)
704− -- wait for our worker to finish final write
705− void (Async.waitCatch worker)
706− -- wait for scribe to finish final write
707− void (scribeFinalizer scribe)
708−
709− let sh = ScribeHandle (scribe { scribeFinalizer = fin }) queue
710− return (le & logEnvScribes %~ M.insert nm sh)
711−
712−
713−-------------------------------------------------------------------------------
714−spawnScribeWorker :: Scribe -> BQ.TBQueue WorkerMessage -> IO (Async.Async ())
715−spawnScribeWorker (Scribe write _ _) queue = Async.async go
716− where
717− go = do
718− newCmd <- atomically (BQ.readTBQueue queue)
719− case newCmd of
720− NewItem a -> do
721− -- Swallow any direct exceptions from the
722− -- scribe. safe-exceptions won't catch async exceptions.
723− void (tryAny (write a))
724− go
725− PoisonPill -> return ()
726−
727−
728−-------------------------------------------------------------------------------
729−data ScribeSettings = ScribeSettings {
730− _scribeBufferSize :: Int
731− }
732− deriving (Show, Eq)
733−
734−makeLenses ''ScribeSettings
735−
736−
737−-- | Reasonable defaults for a scribe. Buffer
738−-- size of 4096.
739−defaultScribeSettings :: ScribeSettings
740−defaultScribeSettings = ScribeSettings 4096
525+ -> LogEnv
526+registerScribe nm h = logEnvScribes %~ M.insert nm h
741527
742528
743529-------------------------------------------------------------------------------
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.
530+-- | Remove a scribe from the list. All future log calls will no
531+-- longer use this scribe. If the given scribe doesn't exist, its a no-op.
748532unregisterScribe
749533 :: Text
750534 -- ^ Name of the scribe
751535 -> LogEnv
752536 -> LogEnv
753−unregisterScribe nm = logEnvScribes %~ M.delete nm
537+unregisterScribe nm = logEnvScribes %~ M.delete nm
754538
755539
756540-------------------------------------------------------------------------------
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.
541+-- | Unregister *all* scribes. Logs will go off into space from this
542+-- point onward until new scribes are added.
761543clearScribes
762544 :: LogEnv
763545 -> LogEnv
@@ -765,128 +547,45 @@ clearScribes = logEnvScribes .~ mempty
765547
766548
767549-------------------------------------------------------------------------------
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
774− :: Text
775− -- ^ Name of the scribe
776− -> LogEnv
777− -> IO LogEnv
778−closeScribe nm le = do
779− maybe (return ()) (scribeFinalizer . shScribe) (M.lookup nm (_logEnvScribes le))
780− return (le & logEnvScribes %~ M.delete nm)
781−
782−
783−-------------------------------------------------------------------------------
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
790− :: LogEnv
791− -> 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)
798−
799−
800−-------------------------------------------------------------------------------
801−-- | Monads where katip logging actions can be performed. Katip is the
802−-- most basic logging monad. You will typically use this directly if
803−-- you either don't want to use namespaces/contexts heavily or if you
804−-- want to pass in specific contexts and/or namespaces at each log site.
805−--
806−-- For something more powerful, look at the docs for 'KatipContext',
807−-- which keeps a namespace and merged context. You can write simple
808−-- functions that add additional namespacing and merges additional
809−-- 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.
815−class MonadIO m => Katip m where
550+-- | Monads where katip logging actions can be performed
551+class MonadIO m => Katip m where
816552 getLogEnv :: m LogEnv
817− localLogEnv :: (LogEnv -> LogEnv) -> m a -> m a
818553
819554
820555instance Katip m => Katip (ReaderT s m) where
821556 getLogEnv = lift getLogEnv
822− localLogEnv = mapReaderT . localLogEnv
823557
824558
825−#if !MIN_VERSION_either(4, 5, 0)
826559instance Katip m => Katip (EitherT s m) where
827560 getLogEnv = lift getLogEnv
828− localLogEnv = mapEitherT . localLogEnv
829−#endif
830−
831561
832562instance Katip m => Katip (ExceptT s m) where
833563 getLogEnv = lift getLogEnv
834− localLogEnv = mapExceptT . localLogEnv
835−
836564
837565instance Katip m => Katip (MaybeT m) where
838566 getLogEnv = lift getLogEnv
839− localLogEnv = mapMaybeT . localLogEnv
840567
841568
842569instance Katip m => Katip (StateT s m) where
843570 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
860571
861572
862573instance (Katip m, Monoid s) => Katip (WriterT s m) where
863574 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−
871575
872576instance (Katip m) => Katip (ResourceT m) where
873577 getLogEnv = lift getLogEnv
874− localLogEnv = transResourceT . localLogEnv
875578
876579
877580-------------------------------------------------------------------------------
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.
581+-- | A concrete monad you can use to run logging actions.
881582newtype KatipT m a = KatipT { unKatipT :: ReaderT LogEnv m a }
882583 deriving ( Functor, Applicative, Monad, MonadIO
883− , MonadMask, MonadCatch, MonadThrow, MonadResource, MonadTrans
884− , MonadBase b)
584+ , MonadMask, MonadCatch, MonadThrow, MonadTrans, MonadBase b)
885585
886586
887587instance MonadIO m => Katip (KatipT m) where
888588 getLogEnv = KatipT ask
889− localLogEnv f (KatipT m) = KatipT $ local f m
890589
891590
892591instance MonadTransControl KatipT where
@@ -902,21 +601,6 @@ instance (MonadBaseControl b m) => MonadBaseControl b (KatipT m) where
902601 liftBaseWith = defaultLiftBaseWith
903602 restoreM = defaultRestoreM
904603
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
920604
921605-------------------------------------------------------------------------------
922606-- | Execute 'KatipT' on a log env.
@@ -924,17 +608,6 @@ runKatipT :: LogEnv -> KatipT m a -> m a
924608runKatipT le (KatipT f) = runReaderT f le
925609
926610
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−
938611-------------------------------------------------------------------------------
939612-- | Log with everything, including a source code location. This is
940613-- very low level and you typically can use 'logT' in its place.
@@ -948,43 +621,20 @@ logItem
948621 -> m ()
949622logItem a ns loc sev msg = do
950623 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)
624+ liftIO $ do
625+ item <- Item
626+ <$> pure _logEnvNs
627+ <*> pure _logEnvEnv
628+ <*> pure sev
629+ <*> (mkThreadIdText <$> myThreadId)
630+ <*> pure _logEnvHost
631+ <*> pure _logEnvPid
632+ <*> pure a
633+ <*> pure msg
634+ <*> _logEnvTimer
635+ <*> pure (_logEnvNs <> ns)
636+ <*> pure loc
637+ FT.forM_ (M.elems _logEnvScribes) $ \ (Scribe h) -> h item
988638
989639
990640-------------------------------------------------------------------------------
@@ -1016,10 +666,10 @@ logException
1016666 -> Severity -- ^ Severity
1017667 -> m b -- ^ Main action being run
1018668 -> m b
1019−logException a ns sev action = action `catchAny` \e -> f e >> throwM e
669+logException a ns sev action = action `catchAll` \e -> f e >> throwM e
1020670 where
1021671 f e = logF a ns sev (msg e)
1022− msg e = ls (T.pack "An exception has occurred: ") <> showLS e
672+ msg e = ls (T.pack "An exception has occured: ") <> showLS e
1023673
1024674
1025675-------------------------------------------------------------------------------
@@ -1047,14 +697,14 @@ instance TH.Lift Verbosity where
1047697
1048698
1049699instance TH.Lift Severity where
1050− lift DebugS = [| DebugS |]
1051− lift InfoS = [| InfoS |]
1052− lift NoticeS = [| NoticeS |]
1053− lift WarningS = [| WarningS |]
1054− lift ErrorS = [| ErrorS |]
700+ lift DebugS = [| DebugS |]
701+ lift InfoS = [| InfoS |]
702+ lift NoticeS = [| NoticeS |]
703+ lift WarningS = [| WarningS |]
704+ lift ErrorS = [| ErrorS |]
1055705 lift CriticalS = [| CriticalS |]
1056− lift AlertS = [| AlertS |]
1057− lift EmergencyS = [| EmergencyS |]
706+ lift AlertS = [| AlertS |]
707+ lift EmergencyS = [| EmergencyS |]
1058708
1059709
1060710-- | Lift a location into an Exp.
@@ -1070,37 +720,9 @@ liftLoc (Loc a b c (d1, d2) (e1, e2)) = [|Loc
1070720
1071721-------------------------------------------------------------------------------
1072722-- | For use when you want to include location in your logs. This will
1073−-- fill the 'Maybe Loc' gap in 'logF' of this module, and relies on implicit
1074−-- callstacks when available (GHC > 7.8).
1075−#if MIN_VERSION_base(4, 8, 0)
1076−getLoc :: HasCallStack => Maybe Loc
1077−getLoc = case getCallStack callStack of
1078− [] -> Nothing
1079− xs -> Just . toLoc . head $ filter filterKatip xs
1080− where
1081− filterKatip :: (String, SrcLoc) -> Bool
1082− filterKatip (_, srcloc) = not $
1083− "katip-" `isPrefixOf` srcLocPackage srcloc
1084−
1085− toLoc :: (String, SrcLoc) -> Loc
1086− toLoc (_, l) = Loc {
1087− loc_filename = srcLocFile l
1088− , loc_package = srcLocPackage l
1089− , loc_module = srcLocModule l
1090− , loc_start = (srcLocStartLine l, srcLocStartCol l)
1091− , loc_end = (srcLocEndLine l, srcLocEndCol l)
1092− }
1093−#else
1094−getLoc :: Maybe Loc
1095−getLoc = Nothing
1096−#endif
1097−
1098−
1099−-------------------------------------------------------------------------------
1100−-- Like `getLoc`, but uses template-haskell and works with older versions of
1101−-- the compiler (GHC 7.8 or older).
1102−getLocTH :: ExpQ
1103−getLocTH = [| $(location >>= liftLoc) |]
723+-- fill the 'Maybe Loc' gap in 'logF' of this module.
724+getLoc :: Q Exp
725+getLoc = [| $(location >>= liftLoc) |]
1104726
1105727
1106728-------------------------------------------------------------------------------
@@ -1108,31 +730,7 @@ getLocTH = [| $(location >>= liftLoc) |]
1108730--
1109731-- @$(logT) obj mempty InfoS "Hello world"@
1110732logT :: ExpQ
1111−logT = [| \ a ns sev msg -> logItem a ns (Just $(getLocTH)) sev msg |]
1112−
1113−
1114−-------------------------------------------------------------------------------
1115−-- | 'Loc'-tagged logging using 'GHC.Stack' when available.
1116−--
1117−-- This function does not require template-haskell as it
1118−-- automatically uses <https://hackage.haskell.org/package/base-4.8.2.0/docs/GHC-Stack.html#v:getCallStack implicit-callstacks>
1119−-- when the code is compiled using GHC > 7.8. Using an older version of the
1120−-- compiler will result in the emission of a log line without any location information,
1121−-- so be aware of it. Users using GHC <= 7.8 may want to use the template-haskell function
1122−-- `logT` for maximum compatibility.
1123−--
1124−-- @logLoc obj mempty InfoS "Hello world"@
1125−#if MIN_VERSION_base(4, 8, 0)
1126−logLoc :: (Applicative m, LogItem a, Katip m, HasCallStack)
1127−#else
1128−logLoc :: (Applicative m, LogItem a, Katip m)
1129−#endif
1130− => a
1131− -> Namespace
1132− -> Severity
1133− -> LogStr
1134− -> m ()
1135−logLoc a ns = logItem a ns getLoc
733+logT = [| \ a ns sev msg -> logItem a ns (Just $(getLoc)) sev msg |]
1136734
1137735
1138736-- taken from the file-location package