@@ -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 #-}
@@ -14,88 +11,47 @@
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
20−-- | This module is not meant to be imported directly and may contain
21−-- internal mechanisms that will change without notice.
2214module Katip.Core where
2315
2416-------------------------------------------------------------------------------
25−import Control.Applicative as A
17+import Control.Applicative as A
2618import Control.AutoUpdate
2719import 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)
20+import Control.Lens
3321import Control.Monad.Base
34−#if MIN_VERSION_base(4, 9, 0)
35−import qualified Control.Monad.Fail as MF
36−#endif
22+import Control.Monad.Catch
3723import Control.Monad.IO.Class
38−import Control.Monad.IO.Unlift
3924import Control.Monad.Trans.Class
4025import Control.Monad.Trans.Control
41−#if !MIN_VERSION_either(4, 5, 0)
4226import Control.Monad.Trans.Either
43−#endif
4427import Control.Monad.Trans.Except
4528import Control.Monad.Trans.Maybe
4629import 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
30+import Control.Monad.Trans.Resource
31+import Control.Monad.Trans.State
32+import Control.Monad.Trans.Writer
33+import Data.Aeson (FromJSON (..), ToJSON (..),
34+ object)
35+import qualified Data.Aeson as A
36+import Data.Foldable as FT
37+import qualified Data.HashMap.Strict as HM
6138import Data.List
62−import qualified Data.Map.Strict as M
63−import Data.Maybe (fromMaybe)
64−import Data.Semigroup as SG
39+import qualified Data.Map.Strict as M
40+import Data.Monoid
6541import Data.String
6642import Data.String.Conv
67−import Data.Text (Text)
68−import qualified Data.Text as T
69−import qualified Data.Text.Lazy.Builder as B
43+import Data.Text (Text)
44+import qualified Data.Text as T
45+import qualified Data.Text.Lazy.Builder as B
7046import 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
47+import GHC.Generics hiding (to)
7848import Language.Haskell.TH
79−import qualified Language.Haskell.TH.Syntax as TH
80−import Lens.Micro
81−import Lens.Micro.TH
49+import qualified Language.Haskell.TH.Syntax as TH
8250import Network.HostName
83−#if mingw32_HOST_OS
84−import Katip.Compat
85−#else
8651import System.Posix
87−#endif
88−
8952-------------------------------------------------------------------------------
9053
9154
92−readMay :: Read a => String -> Maybe a
93−readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
94− [x] -> Just x
95− [] -> Nothing -- no parse
96− _ -> Nothing -- Ambiguous parse
97−
98−
9955-------------------------------------------------------------------------------
10056-- | Represents a heirarchy of namespaces going from general to
10157-- specific. For instance: ["processname", "subsystem"]. Note that
@@ -103,7 +59,7 @@ readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
10359-- IsString/OverloadedStrings, so "foo" will result in Namespace
10460-- ["foo"].
10561newtype Namespace = Namespace { unNamespace :: [Text] }
106− deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,SG.Semigroup,Monoid)
62+ deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,Monoid)
10763
10864instance IsString Namespace where
10965 fromString s = Namespace [fromString s]
@@ -143,81 +99,60 @@ data Severity
14399-- - 'V3' implies the maximum amount of payload information.
144100-- - Anything in between is left to the discretion of the developer.
145101data Verbosity = V0 | V1 | V2 | V3
146− deriving (Eq, Ord, Show, Read, Generic, Enum, Bounded)
102+ deriving (Eq, Ord, Show, Read, Generic, Enum)
147103
148104
149105-------------------------------------------------------------------------------
150106renderSeverity :: Severity -> Text
151107renderSeverity 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"
108+ DebugS -> "Debug"
109+ InfoS -> "Info"
110+ NoticeS -> "Notice"
111+ WarningS -> "Warning"
112+ ErrorS -> "Error"
113+ CriticalS -> "Critical"
114+ AlertS -> "Alert"
159115 EmergencyS -> "Emergency"
160116
161117
162118-------------------------------------------------------------------------------
163−textToSeverity :: Text -> Maybe Severity
164−textToSeverity = go . T.toLower
119+severityText :: Prism' Text Severity
120+severityText = prism renderSeverity toSev
165121 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
175−
122+ toSev "Debug" = Right DebugS
123+ toSev "Info" = Right InfoS
124+ toSev "Notice" = Right NoticeS
125+ toSev "Warning" = Right WarningS
126+ toSev "Error" = Right ErrorS
127+ toSev "Critical" = Right CriticalS
128+ toSev "Alert" = Right AlertS
129+ toSev "Emergency" = Right EmergencyS
130+ toSev x = Left x
176131
177132instance ToJSON Severity where
178− toJSON s = A.String (renderSeverity s)
133+ toJSON s = A.String (s ^. re severityText)
134+
179135
180136instance FromJSON Severity where
181137 parseJSON = A.withText "Severity" parseSeverity
182138 where
183− parseSeverity t = case textToSeverity t of
184− Just x -> return x
139+ parseSeverity t = case t ^? severityText of
140+ Just x -> return x
185141 Nothing -> fail $ "Invalid Severity " ++ toS t
186142
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−
202143
203144-------------------------------------------------------------------------------
204−-- | Log message with Builder underneath; use '<>' to concat in O(1).
145+-- | Log message with Builder unerneath; use '<>' to concat in O(1).
205146newtype LogStr = LogStr { unLogStr :: B.Builder }
206− deriving (Generic, Show, Eq)
147+ deriving (Generic, Show)
207148
208149instance IsString LogStr where
209150 fromString = LogStr . B.fromString
210151
211−
212−instance Semigroup LogStr where
213− (LogStr a) <> (LogStr b) = LogStr (a <> b)
214−
215−
216152instance Monoid LogStr where
217− mappend = (<>)
153+ mappend (LogStr a) (LogStr b) = LogStr (a `mappend` b)
218154 mempty = LogStr mempty
219155
220−
221156instance FromJSON LogStr where
222157 parseJSON = A.withText "LogStr" parseLogStr
223158 where
@@ -225,20 +160,20 @@ instance FromJSON LogStr where
225160
226161-------------------------------------------------------------------------------
227162-- | Pack any string-like thing into a 'LogStr'. This will
228−-- automatically work on 'String', 'ByteString', 'Text' and any of the
163+-- automatically work on 'String', 'ByteString, 'Text' and any of the
229164-- lazy variants.
230165logStr :: StringConv a Text => a -> LogStr
231166logStr t = LogStr (B.fromText $ toS t)
232167
233168
234169-------------------------------------------------------------------------------
235−-- | Shorthand for 'logStr'
170+-- | Shorthand for 'logMsg'
236171ls :: StringConv a Text => a -> LogStr
237172ls = logStr
238173
239174
240175-------------------------------------------------------------------------------
241−-- | Convert any showable type into a 'LogStr'.
176+-- | Convert any showable type into a LogStr.
242177showLS :: Show a => a -> LogStr
243178showLS = ls . show
244179
@@ -250,9 +185,7 @@ newtype ThreadIdText = ThreadIdText {
250185
251186
252187mkThreadIdText :: ThreadId -> ThreadIdText
253−mkThreadIdText = ThreadIdText . stripPrefix' "ThreadId " . T.pack . show
254− where
255− stripPrefix' pfx t = fromMaybe t (T.stripPrefix pfx t)
188+mkThreadIdText = ThreadIdText . T.pack . show
256189
257190
258191-------------------------------------------------------------------------------
@@ -272,62 +205,31 @@ data Item a = Item {
272205 } deriving (Generic, Functor)
273206makeLenses ''Item
274207
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− ]
298208
299209instance 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 <$> _itemLoc)
312− . showChar '}'
313− )
314− where
315− field n v = showString n . showString " = " . shows v . showString ", "
210+ show Item{..} = "Item {_itemApp = " ++ show _itemApp ++ ", " ++
211+ "_itemEnv = " ++ show _itemEnv ++ ", " ++
212+ "_itemSeverity = " ++ show _itemSeverity ++ ", " ++
213+ "_itemThread = " ++ show _itemThread ++ ", " ++
214+ "_itemHost = " ++ show _itemHost ++ ", " ++
215+ "_itemProcess = " ++ show _itemProcess ++ ", " ++
216+ "_itemPayload = " ++ show _itemPayload ++ ", " ++
217+ "_itemMessage = " ++ show _itemMessage ++ ", " ++
218+ "_itemTime = " ++ show _itemTime ++ ", " ++
219+ "_itemNamespace = " ++ show _itemNamespace ++ ", " ++
220+ "_itemLoc = " ++ show (LocShow <$> _itemLoc) ++ "}"
221+
316222
317223newtype LocShow = LocShow Loc
318224
319225
320226instance 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 ", "
227+ show (LocShow Loc{..}) =
228+ "Loc {loc_filename = " ++ show loc_filename ++ ", " ++
229+ "loc_package = " ++ show loc_package ++ ", " ++
230+ "loc_module = " ++ show loc_module ++ ", " ++
231+ "loc_start = " ++ show loc_start ++ ", " ++
232+ "loc_end = " ++ show loc_end ++ "}"
331233
332234
333235instance ToJSON a => ToJSON (Item a) where
@@ -387,12 +289,13 @@ instance FromJSON a => FromJSON (Item a) where
387289 <*> (fmap getLocJs <$> o A..: "loc")
388290
389291
390−processIDToText :: ProcessID -> Text
391−processIDToText = toS . show
392−
393−
394−textToProcessID :: Text -> Maybe ProcessID
395−textToProcessID = readMay . toS
292+processIDText :: Prism' Text ProcessID
293+processIDText = prism fromProcessID toProcessID
294+ where
295+ fromProcessID = toS . show
296+ toProcessID t = case toS t ^? _Show of
297+ Just i -> Right i
298+ Nothing -> Left t
396299
397300
398301newtype ProcessIDJs = ProcessIDJs {
@@ -401,14 +304,14 @@ newtype ProcessIDJs = ProcessIDJs {
401304
402305
403306instance ToJSON ProcessIDJs where
404− toJSON (ProcessIDJs p) = A.String (processIDToText p)
307+ toJSON (ProcessIDJs p) = A.String (p ^. re processIDText)
405308
406309
407310instance FromJSON ProcessIDJs where
408311 parseJSON = A.withText "ProcessID" parseProcessID
409312 where
410− parseProcessID t = case textToProcessID t of
411− Just p -> return $ ProcessIDJs p
313+ parseProcessID t = case t ^? processIDText of
314+ Just p -> return $ ProcessIDJs p
412315 Nothing -> fail $ "Invalid ProcessIDJs " ++ toS t
413316
414317
@@ -417,17 +320,12 @@ instance FromJSON ProcessIDJs where
417320data PayloadSelection
418321 = AllKeys
419322 | SomeKeys [Text]
420− deriving (Show, Eq)
421−
422−instance Semigroup PayloadSelection where
423− AllKeys <> _ = AllKeys
424− _ <> AllKeys = AllKeys
425− SomeKeys as <> SomeKeys bs = SomeKeys (as <> bs)
426−
427323
428324instance Monoid PayloadSelection where
429325 mempty = SomeKeys []
430− mappend = (<>)
326+ mappend AllKeys _ = AllKeys
327+ mappend _ AllKeys = AllKeys
328+ mappend (SomeKeys as) (SomeKeys bs) = SomeKeys (as++bs)
431329
432330
433331-------------------------------------------------------------------------------
@@ -440,12 +338,11 @@ instance Monoid PayloadSelection where
440338-- a ToJSON instance like:
441339--
442340-- > instance ToObject Foo
443−class ToObject a where
341+class ToJSON a => ToObject a where
444342 toObject :: a -> A.Object
445− default toObject :: ToJSON a => a -> A.Object
446343 toObject v = case toJSON v of
447344 A.Object o -> o
448− _ -> mempty
345+ _ -> mempty
449346
450347instance ToObject ()
451348instance ToObject A.Object
@@ -491,22 +388,15 @@ instance ToJSON SimpleLogPayload where
491388 toJSON (SimpleLogPayload as) = object $ map go as
492389 where go (k, AnyLogPayload v) = k A..= v
493390
494−
495391instance ToObject SimpleLogPayload
496392
497−
498393instance LogItem SimpleLogPayload where
499394 payloadKeys V0 _ = SomeKeys []
500− payloadKeys _ _ = AllKeys
501−
502−
503−instance Semigroup SimpleLogPayload where
504− SimpleLogPayload a <> SimpleLogPayload b = SimpleLogPayload (a <> b)
505−
395+ payloadKeys _ _ = AllKeys
506396
507397instance Monoid SimpleLogPayload where
508398 mempty = SimpleLogPayload []
509− mappend = (<>)
399+ SimpleLogPayload a `mappend` SimpleLogPayload b = SimpleLogPayload (a `mappend` b)
510400
511401
512402-------------------------------------------------------------------------------
@@ -520,7 +410,7 @@ sl a b = SimpleLogPayload [(a, AnyLogPayload b)]
520410-- automatically bubble higher verbosity levels to lower ones.
521411payloadObject :: LogItem a => Verbosity -> a -> A.Object
522412payloadObject verb a = case FT.foldMap (flip payloadKeys a) [(V0)..verb] of
523− AllKeys -> toObject a
413+ AllKeys -> toObject a
524414 SomeKeys ks -> HM.filterWithKey (\ k _ -> k `FT.elem` ks) $ toObject a
525415
526416
@@ -540,135 +430,67 @@ itemJson verb a = toJSON $ a & itemPayload %~ payloadObject verb
540430--
541431-- Scribes should always take a 'Severity' and 'Verbosity'.
542432--
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.
433+-- Severity is used to *exclude log messages* that are < the provided
434+-- Severity. For instance, if the user passes InfoS, DebugS items
435+-- should be ignored. Katip provides the 'permitItem' utility for this.
549436--
550437-- Verbosity is used to select keys from the log item's payload. Each
551438-- 'LogItem' instance describes what keys should be retained for each
552439-- Verbosity level. Use the 'payloadObject' utility for extracting the keys
553−-- that should be written.
440+-- that should be permitted.
554441--
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.
442+-- There is no built-in mechanism in katip for telling a scribe that
443+-- its time to shut down. 'unregisterScribe' merely drops it from the
444+-- 'LogEnv'. This means there are 2 ways to handle resources as a scribe:
564445--
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−
446+-- 1. Pass in the resource when the scribe is created. Handle
447+-- allocation and release of the resource elsewhere. This is what the
448+-- Handle scribe does.
449+--
450+-- 2. Return a finalizing function that tells the scribe to shut
451+-- down. @katip-elasticsearch@'s @mkEsScribe@ returns a @IO (Scribe,
452+-- IO ())@. The finalizer will flush any queued log messages and shut
453+-- down gracefully before returning. This can be hooked into your
454+-- application's shutdown routine to ensure you never miss any log
455+-- messages on shutdown.
588456data 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
457+ liPush :: forall a. LogItem a => Item a -> IO ()
630458 }
631459
632460
633−-------------------------------------------------------------------------------
634−data WorkerMessage where
635− NewItem :: LogItem a => Item a -> WorkerMessage
636− PoisonPill :: WorkerMessage
461+instance Monoid Scribe where
462+ mempty = Scribe $ const $ return ()
463+ mappend (Scribe a) (Scribe b) = Scribe $ \ item -> do
464+ a item
465+ b item
637466
638467
639468-------------------------------------------------------------------------------
640469-- | 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)
470+permitItem :: Severity -> Item a -> Bool
471+permitItem sev i = _itemSeverity i >= sev
644472
645473
646474-------------------------------------------------------------------------------
647475data LogEnv = LogEnv {
648476 _logEnvHost :: HostName
649477 , _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"
478+ , _logEnvNs :: Namespace
656479 , _logEnvEnv :: Environment
657480 , _logEnvTimer :: IO UTCTime
658481 -- ^ Action to fetch the timestamp. You can use something like
659482 -- '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
483+ -- some output forms to display logs out of order.
484+ , _logEnvScribes :: M.Map Text Scribe
663485 }
664486makeLenses ''LogEnv
665487
666488
667489-------------------------------------------------------------------------------
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'.
490+-- | Create a reasonable default InitLogEnv. Uses an 'AutoUdate' with
491+-- the default settings as the timer. If you are concerned about
492+-- timestamp precision or event ordering in log outputs like
493+-- ElasticSearch, you should replace the timer with 'getCurrentTime'
672494initLogEnv
673495 :: Namespace
674496 -- ^ A base namespace for this application
@@ -680,84 +502,36 @@ initLogEnv an env = LogEnv
680502 <*> getProcessID
681503 <*> pure an
682504 <*> pure env
683− <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime, updateFreq = 1000 }
505+ <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
684506 <*> pure mempty
685507
686508
687509-------------------------------------------------------------------------------
688510-- | 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.
511+-- scribe in addition to the others.
692512registerScribe
693513 :: Text
694514 -- ^ Name the scribe
695515 -> Scribe
696− -> ScribeSettings
697516 -> 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
517+ -> LogEnv
518+registerScribe nm h = logEnvScribes . at nm .~ Just h
741519
742520
743521-------------------------------------------------------------------------------
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.
522+-- | Remove a scribe from the list. All future log calls will no
523+-- longer use this scribe. If the given scribe doesn't exist, its a no-op.
748524unregisterScribe
749525 :: Text
750526 -- ^ Name of the scribe
751527 -> LogEnv
752528 -> LogEnv
753−unregisterScribe nm = logEnvScribes %~ M.delete nm
529+unregisterScribe nm = logEnvScribes . at nm .~ Nothing
754530
755531
756532-------------------------------------------------------------------------------
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.
533+-- | Unregister *all* scribes. Logs will go off into space from this
534+-- point onward until new scribes are added.
761535clearScribes
762536 :: LogEnv
763537 -> LogEnv
@@ -765,128 +539,45 @@ clearScribes = logEnvScribes .~ mempty
765539
766540
767541-------------------------------------------------------------------------------
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
542+-- | Monads where katip logging actions can be performed
543+class MonadIO m => Katip m where
816544 getLogEnv :: m LogEnv
817− localLogEnv :: (LogEnv -> LogEnv) -> m a -> m a
818545
819546
820547instance Katip m => Katip (ReaderT s m) where
821548 getLogEnv = lift getLogEnv
822− localLogEnv = mapReaderT . localLogEnv
823549
824550
825−#if !MIN_VERSION_either(4, 5, 0)
826551instance Katip m => Katip (EitherT s m) where
827552 getLogEnv = lift getLogEnv
828− localLogEnv = mapEitherT . localLogEnv
829−#endif
830−
831553
832554instance Katip m => Katip (ExceptT s m) where
833555 getLogEnv = lift getLogEnv
834− localLogEnv = mapExceptT . localLogEnv
835−
836556
837557instance Katip m => Katip (MaybeT m) where
838558 getLogEnv = lift getLogEnv
839− localLogEnv = mapMaybeT . localLogEnv
840559
841560
842561instance Katip m => Katip (StateT s m) where
843562 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
860563
861564
862565instance (Katip m, Monoid s) => Katip (WriterT s m) where
863566 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−
871567
872568instance (Katip m) => Katip (ResourceT m) where
873569 getLogEnv = lift getLogEnv
874− localLogEnv = transResourceT . localLogEnv
875570
876571
877572-------------------------------------------------------------------------------
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.
573+-- | A concrete monad you can use to run logging actions.
881574newtype KatipT m a = KatipT { unKatipT :: ReaderT LogEnv m a }
882575 deriving ( Functor, Applicative, Monad, MonadIO
883− , MonadMask, MonadCatch, MonadThrow, MonadResource, MonadTrans
884− , MonadBase b)
576+ , MonadMask, MonadCatch, MonadThrow, MonadTrans, MonadBase b)
885577
886578
887579instance MonadIO m => Katip (KatipT m) where
888580 getLogEnv = KatipT ask
889− localLogEnv f (KatipT m) = KatipT $ local f m
890581
891582
892583instance MonadTransControl KatipT where
@@ -902,21 +593,6 @@ instance (MonadBaseControl b m) => MonadBaseControl b (KatipT m) where
902593 liftBaseWith = defaultLiftBaseWith
903594 restoreM = defaultRestoreM
904595
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
920596
921597-------------------------------------------------------------------------------
922598-- | Execute 'KatipT' on a log env.
@@ -924,17 +600,6 @@ runKatipT :: LogEnv -> KatipT m a -> m a
924600runKatipT le (KatipT f) = runReaderT f le
925601
926602
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−
938603-------------------------------------------------------------------------------
939604-- | Log with everything, including a source code location. This is
940605-- very low level and you typically can use 'logT' in its place.
@@ -948,43 +613,20 @@ logItem
948613 -> m ()
949614logItem a ns loc sev msg = do
950615 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)
616+ liftIO $ do
617+ item <- Item
618+ <$> pure _logEnvNs
619+ <*> pure _logEnvEnv
620+ <*> pure sev
621+ <*> (mkThreadIdText <$> myThreadId)
622+ <*> pure _logEnvHost
623+ <*> pure _logEnvPid
624+ <*> pure a
625+ <*> pure msg
626+ <*> _logEnvTimer
627+ <*> pure (_logEnvNs <> ns)
628+ <*> pure loc
629+ FT.forM_ (M.elems _logEnvScribes) $ \ (Scribe h) -> h item
988630
989631
990632-------------------------------------------------------------------------------
@@ -1016,10 +658,10 @@ logException
1016658 -> Severity -- ^ Severity
1017659 -> m b -- ^ Main action being run
1018660 -> m b
1019−logException a ns sev action = action `catchAny` \e -> f e >> throwM e
661+logException a ns sev action = action `catchAll` \e -> f e >> throwM e
1020662 where
1021663 f e = logF a ns sev (msg e)
1022− msg e = ls (T.pack "An exception has occurred: ") <> showLS e
664+ msg e = ls (T.pack "An exception has occured: ") <> showLS e
1023665
1024666
1025667-------------------------------------------------------------------------------
@@ -1047,14 +689,14 @@ instance TH.Lift Verbosity where
1047689
1048690
1049691instance TH.Lift Severity where
1050− lift DebugS = [| DebugS |]
1051− lift InfoS = [| InfoS |]
1052− lift NoticeS = [| NoticeS |]
1053− lift WarningS = [| WarningS |]
1054− lift ErrorS = [| ErrorS |]
692+ lift DebugS = [| DebugS |]
693+ lift InfoS = [| InfoS |]
694+ lift NoticeS = [| NoticeS |]
695+ lift WarningS = [| WarningS |]
696+ lift ErrorS = [| ErrorS |]
1055697 lift CriticalS = [| CriticalS |]
1056− lift AlertS = [| AlertS |]
1057− lift EmergencyS = [| EmergencyS |]
698+ lift AlertS = [| AlertS |]
699+ lift EmergencyS = [| EmergencyS |]
1058700
1059701
1060702-- | Lift a location into an Exp.
@@ -1070,37 +712,9 @@ liftLoc (Loc a b c (d1, d2) (e1, e2)) = [|Loc
1070712
1071713-------------------------------------------------------------------------------
1072714-- | 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) |]
715+-- fill the 'Maybe Loc' gap in 'logF' of this module.
716+getLoc :: Q Exp
717+getLoc = [| $(location >>= liftLoc) |]
1104718
1105719
1106720-------------------------------------------------------------------------------
@@ -1108,31 +722,7 @@ getLocTH = [| $(location >>= liftLoc) |]
1108722--
1109723-- @$(logT) obj mempty InfoS "Hello world"@
1110724logT :: 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
725+logT = [| \ a ns sev msg -> logItem a ns (Just $(getLoc)) sev msg |]
1136726
1137727
1138728-- taken from the file-location package