{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeOperators #-}

-- |
-- Module      : Instrument.Measurement
-- Copyright   : (c) 2009, 2010 Bryan O'Sullivan
--               (c) 2012, Ozgun Ataman
--
-- License     : BSD-style
module Instrument.Measurement
  ( getTime,
    time,
    time_,
    timeEx,
  )
where

-------------------------------------------------------------------------------

import Control.Exception (SomeException)
import Control.Exception.Safe (MonadCatch, tryAny)
import Control.Monad.IO.Class
import Data.Time.Clock.POSIX (getPOSIXTime)

-------------------------------------------------------------------------------

-- | Measure how long action took, in seconds along with its result
time :: MonadIO m => m a -> m (Double, a)
time :: forall (m :: * -> *) a. MonadIO m => m a -> m (Double, a)
time m a
act = do
  Double
start <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO IO Double
getTime
  !a
result <- m a
act
  Double
end <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO IO Double
getTime
  let !delta :: Double
delta = Double
end forall a. Num a => a -> a -> a
- Double
start
  forall (m :: * -> *) a. Monad m => a -> m a
return (Double
delta, a
result)

-- | Measure how long action took, even if they fail
timeEx :: (MonadCatch m, MonadIO m) => m a -> m (Double, Either SomeException a)
timeEx :: forall (m :: * -> *) a.
(MonadCatch m, MonadIO m) =>
m a -> m (Double, Either SomeException a)
timeEx = forall (m :: * -> *) a. MonadIO m => m a -> m (Double, a)
time forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a.
MonadCatch m =>
m a -> m (Either SomeException a)
tryAny

-- | Just measure how long action takes, discard its result
time_ :: MonadIO m => m a -> m Double
time_ :: forall (m :: * -> *) a. MonadIO m => m a -> m Double
time_ = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (a, b) -> a
fst forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. MonadIO m => m a -> m (Double, a)
time

-------------------------------------------------------------------------------
getTime :: IO Double
getTime :: IO Double
getTime = forall a b. (Real a, Fractional b) => a -> b
realToFrac forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` IO POSIXTime
getPOSIXTime