@@ -1,8 +1,11 @@
2+{-# LANGUAGE DefaultSignatures #-}
1{-# LANGUAGE DeriveFunctor #-}
3{-# LANGUAGE DeriveFunctor #-}
2{-# LANGUAGE DeriveGeneric #-}
4{-# LANGUAGE DeriveGeneric #-}
3{-# LANGUAGE ExistentialQuantification #-}
5{-# LANGUAGE ExistentialQuantification #-}
4{-# LANGUAGE FlexibleContexts #-}
6{-# LANGUAGE FlexibleContexts #-}
5{-# LANGUAGE FlexibleInstances #-}
7{-# LANGUAGE FlexibleInstances #-}
6{-# LANGUAGE GeneralizedNewtypeDeriving #-}
9{-# LANGUAGE GeneralizedNewtypeDeriving #-}
7{-# LANGUAGE MultiParamTypeClasses #-}
10{-# LANGUAGE MultiParamTypeClasses #-}
8{-# LANGUAGE OverloadedStrings #-}
11{-# LANGUAGE OverloadedStrings #-}
@@ -11,55 +14,86 @@
11{-# LANGUAGE TemplateHaskell #-}
14{-# LANGUAGE TemplateHaskell #-}
12{-# LANGUAGE TypeFamilies #-}
15{-# LANGUAGE TypeFamilies #-}
13{-# LANGUAGE UndecidableInstances #-}
16{-# LANGUAGE UndecidableInstances #-}
17+#if MIN_VERSION_base(4, 9, 0)
18+{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
14-- | This module is not meant to be imported directly and may contain
20-- | This module is not meant to be imported directly and may contain
15-- internal mechanisms that will change without notice.
21-- internal mechanisms that will change without notice.
16module Katip.Core where
22module Katip.Core where
18-------------------------------------------------------------------------------
24-------------------------------------------------------------------------------
19−import Control.Applicative as A
25+import Control.Applicative as A
20import Control.AutoUpdate
26import Control.AutoUpdate
21import Control.Concurrent
27import 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)
22import Control.Monad.Base
33import Control.Monad.Base
34+#if MIN_VERSION_base(4, 9, 0)
23−import Control.Monad.Catch
35+import qualified Control.Monad.Fail as MF
24import Control.Monad.IO.Class
37import Control.Monad.IO.Class
38+import Control.Monad.IO.Unlift
25import Control.Monad.Trans.Class
39import Control.Monad.Trans.Class
26import Control.Monad.Trans.Control
40import Control.Monad.Trans.Control
41+#if !MIN_VERSION_either(4, 5, 0)
27import Control.Monad.Trans.Either
42import Control.Monad.Trans.Either
28import Control.Monad.Trans.Except
44import Control.Monad.Trans.Except
29import Control.Monad.Trans.Maybe
45import Control.Monad.Trans.Maybe
30import Control.Monad.Trans.Reader
46import Control.Monad.Trans.Reader
31−import Control.Monad.Trans.Resource
47+import Control.Monad.Trans.Resource (MonadResource, ResourceT,
32−import Control.Monad.Trans.State
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)
33−import Control.Monad.Trans.Writer
53+import Control.Monad.Trans.Writer.Lazy (WriterT, mapWriterT)
54+import qualified Control.Monad.Trans.Writer.Strict as Strict (WriterT,
34−import Data.Aeson (FromJSON (..), ToJSON (..),
56+import Data.Aeson (FromJSON (..), ToJSON (..),
36−import qualified Data.Aeson as A
58+import qualified Data.Aeson as A
37−import Data.Foldable as FT
59+import Data.Foldable as FT
38−import qualified Data.HashMap.Strict as HM
60+import qualified Data.HashMap.Strict as HM
39import Data.List
61import Data.List
40−import qualified Data.Map.Strict as M
62+import qualified Data.Map.Strict as M
41−import Data.Monoid
63+import Data.Maybe (fromMaybe)
64+import Data.Semigroup as SG
42import Data.String
65import Data.String
43import Data.String.Conv
66import Data.String.Conv
44−import Data.Text (Text)
67+import Data.Text (Text)
45−import qualified Data.Text as T
68+import qualified Data.Text as T
46−import qualified Data.Text.Lazy.Builder as B
69+import qualified Data.Text.Lazy.Builder as B
47import Data.Time
70import Data.Time
48−import GHC.Generics hiding (to)
71+import GHC.Generics hiding (to)
72+#if MIN_VERSION_base(4, 8, 0)
73+#if !MIN_VERSION_base(4, 9, 0)
49import Language.Haskell.TH
78import Language.Haskell.TH
50−import qualified Language.Haskell.TH.Syntax as TH
79+import qualified Language.Haskell.TH.Syntax as TH
51import Lens.Micro
80import Lens.Micro
52import Lens.Micro.TH
81import Lens.Micro.TH
53import Network.HostName
82import Network.HostName
54import System.Posix
86import System.Posix
55-------------------------------------------------------------------------------
89-------------------------------------------------------------------------------
58readMay :: Read a => String -> Maybe a
92readMay :: Read a => String -> Maybe a
59readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
93readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
60 [x] -> Just x
94 [x] -> Just x
61− [] -> Nothing -- no parse
95+ [] -> Nothing -- no parse
62− _ -> Nothing -- Ambiguous parse
96+ _ -> Nothing -- Ambiguous parse
65-------------------------------------------------------------------------------
99-------------------------------------------------------------------------------
@@ -69,7 +103,7 @@ readMay s = case [x | (x,t) <- reads s, ("","") <- lex t] of
69-- IsString/OverloadedStrings, so "foo" will result in Namespace
103-- IsString/OverloadedStrings, so "foo" will result in Namespace
70-- ["foo"].
104-- ["foo"].
71newtype Namespace = Namespace { unNamespace :: [Text] }
105newtype Namespace = Namespace { unNamespace :: [Text] }
72− deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,Monoid)
106+ deriving (Eq,Show,Read,Ord,Generic,ToJSON,FromJSON,SG.Semigroup,Monoid)
74instance IsString Namespace where
108instance IsString Namespace where
75 fromString s = Namespace [fromString s]
109 fromString s = Namespace [fromString s]
@@ -109,33 +143,35 @@ data Severity
109-- - 'V3' implies the maximum amount of payload information.
143-- - 'V3' implies the maximum amount of payload information.
110-- - Anything in between is left to the discretion of the developer.
144-- - Anything in between is left to the discretion of the developer.
111data Verbosity = V0 | V1 | V2 | V3
145data Verbosity = V0 | V1 | V2 | V3
112− deriving (Eq, Ord, Show, Read, Generic, Enum)
146+ deriving (Eq, Ord, Show, Read, Generic, Enum, Bounded)
115-------------------------------------------------------------------------------
149-------------------------------------------------------------------------------
116renderSeverity :: Severity -> Text
150renderSeverity :: Severity -> Text
117renderSeverity s = case s of
151renderSeverity s = case s of
118− DebugS -> "Debug"
152+ DebugS -> "Debug"
119− InfoS -> "Info"
153+ InfoS -> "Info"
120− NoticeS -> "Notice"
154+ NoticeS -> "Notice"
121− WarningS -> "Warning"
155+ WarningS -> "Warning"
122− ErrorS -> "Error"
156+ ErrorS -> "Error"
123− CriticalS -> "Critical"
157+ CriticalS -> "Critical"
124− AlertS -> "Alert"
158+ AlertS -> "Alert"
125 EmergencyS -> "Emergency"
159 EmergencyS -> "Emergency"
128-------------------------------------------------------------------------------
162-------------------------------------------------------------------------------
129textToSeverity :: Text -> Maybe Severity
163textToSeverity :: Text -> Maybe Severity
130−textToSeverity "Debug" = Just DebugS
164+textToSeverity = go . T.toLower
166+ go "debug" = Just DebugS
131−textToSeverity "Info" = Just InfoS
167+ go "info" = Just InfoS
132−textToSeverity "Notice" = Just NoticeS
168+ go "notice" = Just NoticeS
133−textToSeverity "Warning" = Just WarningS
169+ go "warning" = Just WarningS
134−textToSeverity "Error" = Just ErrorS
170+ go "error" = Just ErrorS
135−textToSeverity "Critical" = Just CriticalS
171+ go "critical" = Just CriticalS
136−textToSeverity "Alert" = Just AlertS
172+ go "alert" = Just AlertS
137−textToSeverity "Emergency" = Just EmergencyS
173+ go "emergency" = Just EmergencyS
138−textToSeverity _ = Nothing
174+ go _ = Nothing
141instance ToJSON Severity where
177instance ToJSON Severity where
@@ -145,22 +181,43 @@ instance FromJSON Severity where
145 parseJSON = A.withText "Severity" parseSeverity
181 parseJSON = A.withText "Severity" parseSeverity
147 parseSeverity t = case textToSeverity t of
183 parseSeverity t = case textToSeverity t of
148− Just x -> return x
184+ Just x -> return x
149 Nothing -> fail $ "Invalid Severity " ++ toS t
185 Nothing -> fail $ "Invalid Severity " ++ toS t
187+instance ToJSON Verbosity where
188+ toJSON s = A.String $ case s of
194+instance FromJSON Verbosity where
195+ parseJSON = A.withText "Verbosity" $ \s -> case s of
200+ _ -> fail $ "Invalid Verbosity " ++ toS s
152-------------------------------------------------------------------------------
203-------------------------------------------------------------------------------
153−-- | Log message with Builder unerneath; use '<>' to concat in O(1).
204+-- | Log message with Builder underneath; use '<>' to concat in O(1).
154newtype LogStr = LogStr { unLogStr :: B.Builder }
205newtype LogStr = LogStr { unLogStr :: B.Builder }
155− deriving (Generic, Show)
206+ deriving (Generic, Show, Eq)
157instance IsString LogStr where
208instance IsString LogStr where
158 fromString = LogStr . B.fromString
209 fromString = LogStr . B.fromString
212+instance Semigroup LogStr where
213+ (LogStr a) <> (LogStr b) = LogStr (a <> b)
160instance Monoid LogStr where
216instance Monoid LogStr where
161− mappend (LogStr a) (LogStr b) = LogStr (a `mappend` b)
217+ mappend = (<>)
162 mempty = LogStr mempty
218 mempty = LogStr mempty
164instance FromJSON LogStr where
221instance FromJSON LogStr where
165 parseJSON = A.withText "LogStr" parseLogStr
222 parseJSON = A.withText "LogStr" parseLogStr
@@ -168,20 +225,20 @@ instance FromJSON LogStr where
169-------------------------------------------------------------------------------
226-------------------------------------------------------------------------------
170-- | Pack any string-like thing into a 'LogStr'. This will
227-- | Pack any string-like thing into a 'LogStr'. This will
171−-- automatically work on 'String', 'ByteString, 'Text' and any of the
228+-- automatically work on 'String', 'ByteString', 'Text' and any of the
172-- lazy variants.
229-- lazy variants.
173logStr :: StringConv a Text => a -> LogStr
230logStr :: StringConv a Text => a -> LogStr
174logStr t = LogStr (B.fromText $ toS t)
231logStr t = LogStr (B.fromText $ toS t)
177-------------------------------------------------------------------------------
234-------------------------------------------------------------------------------
178−-- | Shorthand for 'logMsg'
235+-- | Shorthand for 'logStr'
179ls :: StringConv a Text => a -> LogStr
236ls :: StringConv a Text => a -> LogStr
180ls = logStr
237ls = logStr
183-------------------------------------------------------------------------------
240-------------------------------------------------------------------------------
184−-- | Convert any showable type into a LogStr.
241+-- | Convert any showable type into a 'LogStr'.
185showLS :: Show a => a -> LogStr
242showLS :: Show a => a -> LogStr
186showLS = ls . show
243showLS = ls . show
@@ -193,7 +250,9 @@ newtype ThreadIdText = ThreadIdText {
195mkThreadIdText :: ThreadId -> ThreadIdText
252mkThreadIdText :: ThreadId -> ThreadIdText
196−mkThreadIdText = ThreadIdText . T.pack . show
253+mkThreadIdText = ThreadIdText . stripPrefix' "ThreadId " . T.pack . show
255+ stripPrefix' pfx t = fromMaybe t (T.stripPrefix pfx t)
199-------------------------------------------------------------------------------
258-------------------------------------------------------------------------------
@@ -213,31 +272,62 @@ data Item a = Item {
213 } deriving (Generic, Functor)
272 } deriving (Generic, Functor)
214makeLenses ''Item
273makeLenses ''Item
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
217instance Show a => Show (Item a) where
299instance Show a => Show (Item a) where
218− show Item{..} = "Item {_itemApp = " ++ show _itemApp ++ ", " ++
300+ showsPrec d Item{..} = showParen (d >= 11) ( showString "Item {"
219− "_itemEnv = " ++ show _itemEnv ++ ", " ++
301+ . field "_itemApp" _itemApp
302+ . field "_itemEnv" _itemEnv
220− "_itemSeverity = " ++ show _itemSeverity ++ ", " ++
303+ . field "_itemSeverity" _itemSeverity
221− "_itemThread = " ++ show _itemThread ++ ", " ++
304+ . field "_itemThread" _itemThread
222− "_itemHost = " ++ show _itemHost ++ ", " ++
305+ . field "_itemHost" _itemHost
223− "_itemProcess = " ++ show _itemProcess ++ ", " ++
306+ . field "_itemProcess" _itemProcess
224− "_itemPayload = " ++ show _itemPayload ++ ", " ++
307+ . field "_itemPayload" _itemPayload
225− "_itemMessage = " ++ show _itemMessage ++ ", " ++
308+ . field "_itemMessage" _itemMessage
226− "_itemTime = " ++ show _itemTime ++ ", " ++
309+ . field "_itemTime" _itemTime
227− "_itemNamespace = " ++ show _itemNamespace ++ ", " ++
310+ . field "_itemNamespace" _itemNamespace
228− "_itemLoc = " ++ show (LocShow <$> _itemLoc) ++ "}"
311+ . showString "_itemLoc = " . shows (LocShow <$> _itemLoc)
315+ field n v = showString n . showString " = " . shows v . showString ", "
231newtype LocShow = LocShow Loc
317newtype LocShow = LocShow Loc
234instance Show LocShow where
320instance Show LocShow where
235− show (LocShow Loc{..}) =
321+ showsPrec d (LocShow Loc{..}) = showParen (d >= 11) ( showString "Loc {"
236− "Loc {loc_filename = " ++ show loc_filename ++ ", " ++
322+ . field "loc_filename" loc_filename
237− "loc_package = " ++ show loc_package ++ ", " ++
323+ . field "loc_package" loc_package
238− "loc_module = " ++ show loc_module ++ ", " ++
324+ . field "loc_module" loc_module
239− "loc_start = " ++ show loc_start ++ ", " ++
325+ . field "loc_start" loc_start
240− "loc_end = " ++ show loc_end ++ "}"
326+ . showString "loc_end = " . shows loc_end
330+ field n v = showString n . showString " = " . shows v . showString ", "
243instance ToJSON a => ToJSON (Item a) where
333instance ToJSON a => ToJSON (Item a) where
@@ -318,7 +408,7 @@ instance FromJSON ProcessIDJs where
318 parseJSON = A.withText "ProcessID" parseProcessID
408 parseJSON = A.withText "ProcessID" parseProcessID
320 parseProcessID t = case textToProcessID t of
410 parseProcessID t = case textToProcessID t of
321− Just p -> return $ ProcessIDJs p
411+ Just p -> return $ ProcessIDJs p
322 Nothing -> fail $ "Invalid ProcessIDJs " ++ toS t
412 Nothing -> fail $ "Invalid ProcessIDJs " ++ toS t
@@ -327,12 +417,17 @@ instance FromJSON ProcessIDJs where
327data PayloadSelection
417data PayloadSelection
328 = AllKeys
418 = AllKeys
329 | SomeKeys [Text]
419 | SomeKeys [Text]
422+instance Semigroup PayloadSelection where
423+ AllKeys <> _ = AllKeys
424+ _ <> AllKeys = AllKeys
425+ SomeKeys as <> SomeKeys bs = SomeKeys (as <> bs)
331instance Monoid PayloadSelection where
428instance Monoid PayloadSelection where
332 mempty = SomeKeys []
429 mempty = SomeKeys []
333− mappend AllKeys _ = AllKeys
430+ mappend = (<>)
334− mappend _ AllKeys = AllKeys
335− mappend (SomeKeys as) (SomeKeys bs) = SomeKeys (as++bs)
338-------------------------------------------------------------------------------
433-------------------------------------------------------------------------------
@@ -345,11 +440,12 @@ instance Monoid PayloadSelection where
345-- a ToJSON instance like:
440-- a ToJSON instance like:
347-- > instance ToObject Foo
442-- > instance ToObject Foo
348−class ToJSON a => ToObject a where
443+class ToObject a where
349 toObject :: a -> A.Object
444 toObject :: a -> A.Object
445+ default toObject :: ToJSON a => a -> A.Object
350 toObject v = case toJSON v of
446 toObject v = case toJSON v of
351 A.Object o -> o
447 A.Object o -> o
352− _ -> mempty
448+ _ -> mempty
354instance ToObject ()
450instance ToObject ()
355instance ToObject A.Object
451instance ToObject A.Object
@@ -395,15 +491,22 @@ instance ToJSON SimpleLogPayload where
395 toJSON (SimpleLogPayload as) = object $ map go as
491 toJSON (SimpleLogPayload as) = object $ map go as
396 where go (k, AnyLogPayload v) = k A..= v
492 where go (k, AnyLogPayload v) = k A..= v
398instance ToObject SimpleLogPayload
495instance ToObject SimpleLogPayload
400instance LogItem SimpleLogPayload where
498instance LogItem SimpleLogPayload where
401 payloadKeys V0 _ = SomeKeys []
499 payloadKeys V0 _ = SomeKeys []
402− payloadKeys _ _ = AllKeys
500+ payloadKeys _ _ = AllKeys
503+instance Semigroup SimpleLogPayload where
504+ SimpleLogPayload a <> SimpleLogPayload b = SimpleLogPayload (a <> b)
404instance Monoid SimpleLogPayload where
507instance Monoid SimpleLogPayload where
405 mempty = SimpleLogPayload []
508 mempty = SimpleLogPayload []
406− SimpleLogPayload a `mappend` SimpleLogPayload b = SimpleLogPayload (a `mappend` b)
509+ mappend = (<>)
409-------------------------------------------------------------------------------
512-------------------------------------------------------------------------------
@@ -417,7 +520,7 @@ sl a b = SimpleLogPayload [(a, AnyLogPayload b)]
417-- automatically bubble higher verbosity levels to lower ones.
520-- automatically bubble higher verbosity levels to lower ones.
418payloadObject :: LogItem a => Verbosity -> a -> A.Object
521payloadObject :: LogItem a => Verbosity -> a -> A.Object
419payloadObject verb a = case FT.foldMap (flip payloadKeys a) [(V0)..verb] of
522payloadObject verb a = case FT.foldMap (flip payloadKeys a) [(V0)..verb] of
420− AllKeys -> toObject a
523+ AllKeys -> toObject a
421 SomeKeys ks -> HM.filterWithKey (\ k _ -> k `FT.elem` ks) $ toObject a
524 SomeKeys ks -> HM.filterWithKey (\ k _ -> k `FT.elem` ks) $ toObject a
@@ -437,67 +540,135 @@ itemJson verb a = toJSON $ a & itemPayload %~ payloadObject verb
438-- Scribes should always take a 'Severity' and 'Verbosity'.
541-- Scribes should always take a 'Severity' and 'Verbosity'.
440−-- Severity is used to *exclude log messages* that are < the provided
543+-- Severity is used to __exclude log messages__ that are lower than
441−-- Severity. For instance, if the user passes InfoS, DebugS items
544+-- the provided Severity. For instance, if the user passes InfoS,
442−-- should be ignored. Katip provides the 'permitItem' utility for this.
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
444-- Verbosity is used to select keys from the log item's payload. Each
550-- Verbosity is used to select keys from the log item's payload. Each
445-- 'LogItem' instance describes what keys should be retained for each
551-- 'LogItem' instance describes what keys should be retained for each
446-- Verbosity level. Use the 'payloadObject' utility for extracting the keys
552-- Verbosity level. Use the 'payloadObject' utility for extracting the keys
447−-- that should be permitted.
553+-- that should be written.
449−-- There is no built-in mechanism in katip for telling a scribe that
450−-- its time to shut down. 'unregisterScribe' merely drops it from the
451−-- 'LogEnv'. This means there are 2 ways to handle resources as a scribe:
453−-- 1. Pass in the resource when the scribe is created. Handle
555+-- Scribes provide a finalizer IO action ('scribeFinalizer') that is
454−-- allocation and release of the resource elsewhere. This is what the
556+-- meant to synchronously flush any remaining writes and clean up any
455−-- Handle scribe does.
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
457−-- 2. Return a finalizing function that tells the scribe to shut
565+-- While katip internally buffers messages per 'ScribeSettings', it
458−-- down. @katip-elasticsearch@'s @mkEsScribe@ returns a @IO (Scribe,
566+-- sends them one at a time to the scribe. Depending on the scribe
459−-- IO ())@. The finalizer will flush any queued log messages and shut
567+-- itself, it may make sense for that scribe to keep its own internal
460−-- down gracefully before returning. This can be hooked into your
568+-- buffer to batch-send logs if writing items one at a time is not
461−-- application's shutdown routine to ensure you never miss any log
569+-- efficient. The scribe implementer must be sure that on
462−-- messages on shutdown.
570+-- finalization, all writes are committed synchronously.
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
579+-- | AND together 2 permit functions
580+permitAND :: PermitFunc -> PermitFunc -> PermitFunc
581+permitAND f1 f2 = \a -> liftA2 (&&) (f1 a) (f2 a)
583+-- | OR together 2 permit functions
584+permitOR :: PermitFunc -> PermitFunc -> PermitFunc
585+permitOR f1 f2 = \a -> liftA2 (||) (f1 a) (f2 a)
463data Scribe = Scribe {
588data Scribe = Scribe {
464− liPush :: forall a. LogItem a => Item a -> IO ()
589+ liPush :: forall a. LogItem a => Item a -> IO ()
465− }
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'
604+whenM :: Monad m => m Bool -> m () -> m ()
605+whenM mbool = (>>=) mbool . flip when
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
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)
617+ (finA `finally` finB)
618+ (permitOR permitA permitB)
468instance Monoid Scribe where
621instance Monoid Scribe where
469− mempty = Scribe $ const $ return ()
622+ mempty = Scribe (const (return ())) (return ()) (permitItem DebugS)
470− mappend (Scribe a) (Scribe b) = Scribe $ \ item -> do
623+ mappend = (<>)
626+-------------------------------------------------------------------------------
627+data ScribeHandle = ScribeHandle {
629+ , shChan :: BQ.TBQueue WorkerMessage
633+-------------------------------------------------------------------------------
634+data WorkerMessage where
635+ NewItem :: LogItem a => Item a -> WorkerMessage
636+ PoisonPill :: WorkerMessage
475-------------------------------------------------------------------------------
639-------------------------------------------------------------------------------
476-- | Should this item be logged given the user's maximum severity?
640-- | Should this item be logged given the user's maximum severity?
641+-- Most new scribes will use this as a base for their 'PermitFunc'
477−permitItem :: Severity -> Item a -> Bool
642+permitItem :: Monad m => Severity -> Item a -> m Bool
478−permitItem sev i = _itemSeverity i >= sev
643+permitItem sev item = return (_itemSeverity item >= sev)
481-------------------------------------------------------------------------------
646-------------------------------------------------------------------------------
482data LogEnv = LogEnv {
647data LogEnv = LogEnv {
483 _logEnvHost :: HostName
648 _logEnvHost :: HostName
484 , _logEnvPid :: ProcessID
649 , _logEnvPid :: ProcessID
485− , _logEnvNs :: Namespace
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 , _logEnvEnv :: Environment
656 , _logEnvEnv :: Environment
487 , _logEnvTimer :: IO UTCTime
657 , _logEnvTimer :: IO UTCTime
488 -- ^ Action to fetch the timestamp. You can use something like
658 -- ^ Action to fetch the timestamp. You can use something like
489 -- 'AutoUpdate' for high volume logs but note that this may cause
659 -- 'AutoUpdate' for high volume logs but note that this may cause
490− -- some output forms to display logs out of order.
660+ -- some output forms to display logs out of order. Alternatively,
661+ -- you could just use 'getCurrentTime'.
491− , _logEnvScribes :: M.Map Text Scribe
662+ , _logEnvScribes :: M.Map Text ScribeHandle
493makeLenses ''LogEnv
664makeLenses ''LogEnv
496-------------------------------------------------------------------------------
667-------------------------------------------------------------------------------
497−-- | Create a reasonable default InitLogEnv. Uses an 'AutoUdate' with
668+-- | Create a reasonable default InitLogEnv. Uses an 'AutoUpdate' which
498−-- the default settings as the timer. If you are concerned about
669+-- updates the timer every 1ms. If you need even more timestamp
499−-- timestamp precision or event ordering in log outputs like
670+-- precision at the cost of performance, consider setting
500−-- ElasticSearch, you should replace the timer with 'getCurrentTime'
671+-- '_logEnvTimer' with 'getCurrentTime'.
501initLogEnv
672initLogEnv
502 :: Namespace
673 :: Namespace
503 -- ^ A base namespace for this application
674 -- ^ A base namespace for this application
@@ -509,36 +680,84 @@ initLogEnv an env = LogEnv
509 <*> getProcessID
680 <*> getProcessID
510 <*> pure an
681 <*> pure an
511 <*> pure env
682 <*> pure env
512− <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
683+ <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime, updateFreq = 1000 }
513 <*> pure mempty
684 <*> pure mempty
516-------------------------------------------------------------------------------
687-------------------------------------------------------------------------------
517-- | Add a scribe to the list. All future log calls will go to this
688-- | Add a scribe to the list. All future log calls will go to this
518−-- scribe in addition to the others.
689+-- scribe in addition to the others. Writes will be buffered per the
690+-- ScribeSettings to prevent slow scribes from slowing down
691+-- logging. Writes will be dropped if the buffer fills.
519registerScribe
692registerScribe
521 -- ^ Name the scribe
694 -- ^ Name the scribe
522 -> Scribe
695 -> Scribe
523 -> LogEnv
697 -> LogEnv
524− -> LogEnv
698+ -> IO LogEnv
699+registerScribe nm scribe ScribeSettings {..} le = do
700+ queue <- atomically (BQ.newTBQueue (fromIntegral _scribeBufferSize))
701+ worker <- spawnScribeWorker scribe queue
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)
709+ let sh = ScribeHandle (scribe { scribeFinalizer = fin }) queue
525−registerScribe nm h = logEnvScribes %~ M.insert nm h
710+ return (le & logEnvScribes %~ M.insert nm sh)
713+-------------------------------------------------------------------------------
714+spawnScribeWorker :: Scribe -> BQ.TBQueue WorkerMessage -> IO (Async.Async ())
715+spawnScribeWorker (Scribe write _ _) queue = Async.async go
718+ newCmd <- atomically (BQ.readTBQueue queue)
721+ -- Swallow any direct exceptions from the
722+ -- scribe. safe-exceptions won't catch async exceptions.
723+ void (tryAny (write a))
725+ PoisonPill -> return ()
528-------------------------------------------------------------------------------
728-------------------------------------------------------------------------------
529−-- | Remove a scribe from the list. All future log calls will no
729+data ScribeSettings = ScribeSettings {
530−-- longer use this scribe. If the given scribe doesn't exist, its a no-op.
730+ _scribeBufferSize :: Int
734+makeLenses ''ScribeSettings
737+-- | Reasonable defaults for a scribe. Buffer
739+defaultScribeSettings :: ScribeSettings
740+defaultScribeSettings = ScribeSettings 4096
743+-------------------------------------------------------------------------------
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.
531unregisterScribe
748unregisterScribe
533 -- ^ Name of the scribe
750 -- ^ Name of the scribe
534 -> LogEnv
751 -> LogEnv
535 -> LogEnv
752 -> LogEnv
536−unregisterScribe nm = logEnvScribes %~ M.delete nm
753+unregisterScribe nm = logEnvScribes %~ M.delete nm
539-------------------------------------------------------------------------------
756-------------------------------------------------------------------------------
540−-- | Unregister *all* scribes. Logs will go off into space from this
757+-- | Unregister __all__ scribes. Note that this is __not__ for closing or
541−-- point onward until new scribes are added.
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.
542clearScribes
761clearScribes
543 :: LogEnv
762 :: LogEnv
544 -> LogEnv
763 -> LogEnv
@@ -546,45 +765,128 @@ clearScribes = logEnvScribes .~ mempty
548-------------------------------------------------------------------------------
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.
775+ -- ^ Name of the scribe
778+closeScribe nm le = do
779+ maybe (return ()) (scribeFinalizer . shScribe) (M.lookup nm (_logEnvScribes le))
780+ return (le & logEnvScribes %~ M.delete nm)
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.
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)
800+-------------------------------------------------------------------------------
549−-- | Monads where katip logging actions can be performed
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.
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.
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.
550−class MonadIO m => Katip m where
815+class MonadIO m => Katip m where
551 getLogEnv :: m LogEnv
816 getLogEnv :: m LogEnv
817+ localLogEnv :: (LogEnv -> LogEnv) -> m a -> m a
554instance Katip m => Katip (ReaderT s m) where
820instance Katip m => Katip (ReaderT s m) where
555 getLogEnv = lift getLogEnv
821 getLogEnv = lift getLogEnv
822+ localLogEnv = mapReaderT . localLogEnv
825+#if !MIN_VERSION_either(4, 5, 0)
558instance Katip m => Katip (EitherT s m) where
826instance Katip m => Katip (EitherT s m) where
559 getLogEnv = lift getLogEnv
827 getLogEnv = lift getLogEnv
828+ localLogEnv = mapEitherT . localLogEnv
561instance Katip m => Katip (ExceptT s m) where
832instance Katip m => Katip (ExceptT s m) where
562 getLogEnv = lift getLogEnv
833 getLogEnv = lift getLogEnv
834+ localLogEnv = mapExceptT . localLogEnv
564instance Katip m => Katip (MaybeT m) where
837instance Katip m => Katip (MaybeT m) where
565 getLogEnv = lift getLogEnv
838 getLogEnv = lift getLogEnv
839+ localLogEnv = mapMaybeT . localLogEnv
568instance Katip m => Katip (StateT s m) where
842instance Katip m => Katip (StateT s m) where
569 getLogEnv = lift getLogEnv
843 getLogEnv = lift getLogEnv
844+ localLogEnv = mapStateT . localLogEnv
847+instance (Katip m, Monoid w) => Katip (RWST r w s m) where
848+ getLogEnv = lift getLogEnv
849+ localLogEnv = mapRWST . localLogEnv
852+instance (Katip m, Monoid w) => Katip (Strict.RWST r w s m) where
853+ getLogEnv = lift getLogEnv
854+ localLogEnv = Strict.mapRWST . localLogEnv
857+instance Katip m => Katip (Strict.StateT s m) where
858+ getLogEnv = lift getLogEnv
859+ localLogEnv = Strict.mapStateT . localLogEnv
572instance (Katip m, Monoid s) => Katip (WriterT s m) where
862instance (Katip m, Monoid s) => Katip (WriterT s m) where
573 getLogEnv = lift getLogEnv
863 getLogEnv = lift getLogEnv
864+ localLogEnv = mapWriterT . localLogEnv
867+instance (Katip m, Monoid s) => Katip (Strict.WriterT s m) where
868+ getLogEnv = lift getLogEnv
869+ localLogEnv = Strict.mapWriterT . localLogEnv
575instance (Katip m) => Katip (ResourceT m) where
872instance (Katip m) => Katip (ResourceT m) where
576 getLogEnv = lift getLogEnv
873 getLogEnv = lift getLogEnv
874+ localLogEnv = transResourceT . localLogEnv
579-------------------------------------------------------------------------------
877-------------------------------------------------------------------------------
580−-- | A concrete monad you can use to run logging actions.
878+-- | A concrete monad you can use to run logging actions. Use this if
879+-- you prefer an explicit monad transformer stack and adding layers as
880+-- opposed to implementing 'Katip' for your monad.
581newtype KatipT m a = KatipT { unKatipT :: ReaderT LogEnv m a }
881newtype KatipT m a = KatipT { unKatipT :: ReaderT LogEnv m a }
582 deriving ( Functor, Applicative, Monad, MonadIO
882 deriving ( Functor, Applicative, Monad, MonadIO
583− , MonadMask, MonadCatch, MonadThrow, MonadTrans, MonadBase b)
883+ , MonadMask, MonadCatch, MonadThrow, MonadResource, MonadTrans
586instance MonadIO m => Katip (KatipT m) where
887instance MonadIO m => Katip (KatipT m) where
587 getLogEnv = KatipT ask
888 getLogEnv = KatipT ask
889+ localLogEnv f (KatipT m) = KatipT $ local f m
590instance MonadTransControl KatipT where
892instance MonadTransControl KatipT where
@@ -600,6 +902,21 @@ instance (MonadBaseControl b m) => MonadBaseControl b (KatipT m) where
600 liftBaseWith = defaultLiftBaseWith
902 liftBaseWith = defaultLiftBaseWith
601 restoreM = defaultRestoreM
903 restoreM = defaultRestoreM
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)
910+ askUnliftIO = KatipT $
911+ withUnliftIO $ \u ->
912+ pure (UnliftIO (unliftIO u . unKatipT))
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)
604-------------------------------------------------------------------------------
921-------------------------------------------------------------------------------
605-- | Execute 'KatipT' on a log env.
922-- | Execute 'KatipT' on a log env.
@@ -607,6 +924,17 @@ runKatipT :: LogEnv -> KatipT m a -> m a
607runKatipT le (KatipT f) = runReaderT f le
924runKatipT le (KatipT f) = runReaderT f le
927+-------------------------------------------------------------------------------
928+-- | Disable all scribes for the given monadic action, then restore
929+-- them afterwards. Works in any Katip monad.
935+katipNoLogging = localLogEnv (\le -> set logEnvScribes mempty le)
610-------------------------------------------------------------------------------
938-------------------------------------------------------------------------------
611-- | Log with everything, including a source code location. This is
939-- | Log with everything, including a source code location. This is
612-- very low level and you typically can use 'logT' in its place.
940-- very low level and you typically can use 'logT' in its place.
@@ -620,20 +948,43 @@ logItem
621logItem a ns loc sev msg = do
949logItem a ns loc sev msg = do
622 LogEnv{..} <- getLogEnv
950 LogEnv{..} <- getLogEnv
623− liftIO $ do
951+ logKatipItem =<< liftIO
624− item <- Item
952+ (Item <$> pure _logEnvApp
626− <*> pure _logEnvEnv
953+ <*> pure _logEnvEnv
627− <*> pure sev
954+ <*> pure sev
628− <*> (mkThreadIdText <$> myThreadId)
955+ <*> (mkThreadIdText <$> myThreadId)
629− <*> pure _logEnvHost
956+ <*> pure _logEnvHost
630− <*> pure _logEnvPid
957+ <*> pure _logEnvPid
631− <*> pure a
958+ <*> pure a
632− <*> pure msg
959+ <*> pure msg
633− <*> _logEnvTimer
960+ <*> _logEnvTimer
634− <*> pure (_logEnvNs <> ns)
961+ <*> pure (_logEnvApp <> ns)
635− <*> pure loc
962+ <*> pure loc)
964+-- | Log already constructed 'Item'. This is the lowest level function that other log*
966+-- It can be useful when implementing centralised logging services.
968+ :: (A.Applicative m, LogItem a, Katip m)
971+logKatipItem item = do
972+ LogEnv{..} <- getLogEnv
636− FT.forM_ (M.elems _logEnvScribes) $ \ (Scribe h) -> h item
974+ FT.forM_ (M.elems _logEnvScribes) $ \ ScribeHandle {..} -> do
975+ whenM (scribePermitItem shScribe item) $
976+ void $ atomically (tryWriteTBQueue shChan (NewItem item))
978+-------------------------------------------------------------------------------
984+tryWriteTBQueue q a = do
985+ full <- isFullTBQueue q
986+ unless full (writeTBQueue q a)
639-------------------------------------------------------------------------------
990-------------------------------------------------------------------------------
@@ -665,10 +1016,10 @@ logException
665 -> Severity -- ^ Severity
1016 -> Severity -- ^ Severity
666 -> m b -- ^ Main action being run
1017 -> m b -- ^ Main action being run
668−logException a ns sev action = action `catchAll` \e -> f e >> throwM e
1019+logException a ns sev action = action `catchAny` \e -> f e >> throwM e
670 f e = logF a ns sev (msg e)
1021 f e = logF a ns sev (msg e)
671− msg e = ls (T.pack "An exception has occured: ") <> showLS e
1022+ msg e = ls (T.pack "An exception has occurred: ") <> showLS e
674-------------------------------------------------------------------------------
1025-------------------------------------------------------------------------------
@@ -696,14 +1047,14 @@ instance TH.Lift Verbosity where
698instance TH.Lift Severity where
1049instance TH.Lift Severity where
699− lift DebugS = [| DebugS |]
1050+ lift DebugS = [| DebugS |]
700− lift InfoS = [| InfoS |]
1051+ lift InfoS = [| InfoS |]
701− lift NoticeS = [| NoticeS |]
1052+ lift NoticeS = [| NoticeS |]
702− lift WarningS = [| WarningS |]
1053+ lift WarningS = [| WarningS |]
703− lift ErrorS = [| ErrorS |]
1054+ lift ErrorS = [| ErrorS |]
704 lift CriticalS = [| CriticalS |]
1055 lift CriticalS = [| CriticalS |]
705− lift AlertS = [| AlertS |]
1056+ lift AlertS = [| AlertS |]
706− lift EmergencyS = [| EmergencyS |]
1057+ lift EmergencyS = [| EmergencyS |]
709-- | Lift a location into an Exp.
1060-- | Lift a location into an Exp.
@@ -719,9 +1070,37 @@ liftLoc (Loc a b c (d1, d2) (e1, e2)) = [|Loc
720-------------------------------------------------------------------------------
1071-------------------------------------------------------------------------------
721-- | For use when you want to include location in your logs. This will
1072-- | For use when you want to include location in your logs. This will
722−-- fill the 'Maybe Loc' gap in 'logF' of this module.
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
1079+ xs -> Just . toLoc . head $ filter filterKatip xs
1081+ filterKatip :: (String, SrcLoc) -> Bool
1082+ filterKatip (_, srcloc) = not $
1083+ "katip-" `isPrefixOf` srcLocPackage srcloc
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)
723−getLoc :: Q Exp
1094+getLoc :: Maybe Loc
1099+-------------------------------------------------------------------------------
1100+-- Like `getLoc`, but uses template-haskell and works with older versions of
1101+-- the compiler (GHC 7.8 or older).
724−getLoc = [| $(location >>= liftLoc) |]
1103+getLocTH = [| $(location >>= liftLoc) |]
727-------------------------------------------------------------------------------
1106-------------------------------------------------------------------------------
@@ -729,7 +1108,31 @@ getLoc = [| $(location >>= liftLoc) |]
730-- @$(logT) obj mempty InfoS "Hello world"@
1109-- @$(logT) obj mempty InfoS "Hello world"@
731logT :: ExpQ
1110logT :: ExpQ
732−logT = [| \ a ns sev msg -> logItem a ns (Just $(getLoc)) sev msg |]
1111+logT = [| \ a ns sev msg -> logItem a ns (Just $(getLocTH)) sev msg |]
1114+-------------------------------------------------------------------------------
1115+-- | 'Loc'-tagged logging using 'GHC.Stack' when available.
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.
1124+-- @logLoc obj mempty InfoS "Hello world"@
1125+#if MIN_VERSION_base(4, 8, 0)
1126+logLoc :: (Applicative m, LogItem a, Katip m, HasCallStack)
1128+logLoc :: (Applicative m, LogItem a, Katip m)
1135+logLoc a ns = logItem a ns getLoc
735-- taken from the file-location package
1138-- taken from the file-location package