Safe Haskell	None
Language	Haskell2010

Control.Monad.Trace

Description

This module is useful for tracing backend implementors. If you are only interested in adding tracing to an application, start at Monitor.Tracing.

Synopsis

data TraceT m a
runTraceT :: TraceT m a -> Tracer -> m a
data Tracer = Tracer {
- tracerChannel :: TChan (Span, Tags, Logs, Interval)
- tracerPendingCount :: TVar Int
}
type Tags = Map Key Value
type Logs = [(POSIXTime, Key, Value)]
data Interval = Interval {
- intervalStart :: !POSIXTime
- intervalDuration :: !NominalDiffTime
}
newTracer :: MonadIO m => m Tracer

Documentation

data TraceT m a Source #

Asynchronous trace collection monad.

Instances

MonadTrans TraceT Source #
Instance details Defined in Control.Monad.Trace Methods lift :: Monad m => m a -> TraceT m a #
MonadReader r m => MonadReader r (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods ask :: TraceT m r # local :: (r -> r) -> TraceT m a -> TraceT m a # reader :: (r -> a) -> TraceT m a #
Monad m => Monad (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods (>>=) :: TraceT m a -> (a -> TraceT m b) -> TraceT m b # (>>) :: TraceT m a -> TraceT m b -> TraceT m b # return :: a -> TraceT m a # fail :: String -> TraceT m a #
Functor m => Functor (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods fmap :: (a -> b) -> TraceT m a -> TraceT m b # (<$) :: a -> TraceT m b -> TraceT m a #
Applicative m => Applicative (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods pure :: a -> TraceT m a # (<>) :: TraceT m (a -> b) -> TraceT m a -> TraceT m b # liftA2 :: (a -> b -> c) -> TraceT m a -> TraceT m b -> TraceT m c # (>) :: TraceT m a -> TraceT m b -> TraceT m b # (<*) :: TraceT m a -> TraceT m b -> TraceT m a #
MonadIO m => MonadIO (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods liftIO :: IO a -> TraceT m a #
MonadUnliftIO m => MonadUnliftIO (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods askUnliftIO :: TraceT m (UnliftIO (TraceT m)) # withRunInIO :: ((forall a. TraceT m a -> IO a) -> IO b) -> TraceT m b #
MonadUnliftIO m => MonadTrace (TraceT m) Source #
Instance details Defined in Control.Monad.Trace Methods trace :: Builder -> TraceT m a -> TraceT m a Source # activeSpan :: TraceT m (Maybe Span) Source # addSpanEntry :: Key -> Value -> TraceT m () Source #

runTraceT :: TraceT m a -> Tracer -> m a Source #

Trace an action.

data Tracer Source #

A tracer collects spans emitted inside TraceT.

Constructors

Tracer
Fields tracerChannel :: TChan (Span, Tags, Logs, Interval) Channel spans get written to when they complete. tracerPendingCount :: TVar Int The number of spans currently in flight (started but not yet completed).

type Tags = Map Key Value Source #

A collection of span tags.

type Logs = [(POSIXTime, Key, Value)] Source #

A collection of span logs, sorted in chronological order.

data Interval Source #

Timing information about a span.

Constructors

Interval
Fields intervalStart :: !POSIXTime intervalDuration :: !NominalDiffTime

newTracer :: MonadIO m => m Tracer Source #

Creates a new Tracer.