debug-time (empty) → 0.1.0.0

raw patch · 5 files changed

+134/−0 lines, 5 filesdep +basedep +clockdep +containerssetup-changed

Dependencies added: base, clock, containers, debug-time

Files

• LICENSE +30/−0
• Setup.hs +2/−0
• debug-time.cabal +31/−0
• src/Debug/Time.hs +47/−0
• test/Test.hs +24/−0

@@ -0,0 +1,30 @@+Copyright Luka Horvat (c) 2015++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.++    * Redistributions in binary form must reproduce the above+      copyright notice, this list of conditions and the following+      disclaimer in the documentation and/or other materials provided+      with the distribution.++    * Neither the name of Luka Horvat nor the names of other+      contributors may be used to endorse or promote products derived+      from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

@@ -0,0 +1,31 @@+name:                debug-time+version:             0.1.0.0+synopsis:            Debug.Trace equivalent for timing computations+description:         Please see README.md+homepage:            http://github.com/LukaHorvat/debug-time#readme+license:             MIT+license-file:        LICENSE+author:              Luka Horvat+maintainer:          example@example.com+copyright:           2015 Luka Horvat+category:            Debug+build-type:          Simple+cabal-version:       >=1.10++library+  hs-source-dirs:      src+  default-language:    Haskell2010+  exposed-modules:     Debug.Time+  build-depends:       base >= 4.7 && < 5+                     , containers+                     , clock+  ghc-options:         -Wall++test-suite test+  type:                exitcode-stdio-1.0+  hs-source-dirs:      test+  main-is:             Test.hs+  default-language:    Haskell2010+  build-depends:       base >= 4.7 && < 5+                     , debug-time+  ghc-options:         -Wall

@@ -0,0 +1,47 @@+{-# OPTIONS_GHC -fno-cse -fno-full-laziness #-}
+module Debug.Time (startTimer, traceTimer, restartTimer, initializeTimers) where
+
+import Data.Map (Map)
+import qualified Data.Map as Map
+import System.Clock (TimeSpec, timeSpecAsNanoSecs, getTime, diffTimeSpec, Clock(Monotonic))
+import System.IO.Unsafe (unsafePerformIO)
+import Data.IORef (IORef)
+import qualified Data.IORef as Ref
+import Debug.Trace (trace)
+import Control.Monad (void)
+import Numeric
+
+{-# NOINLINE timers #-}
+timers :: IORef (Map String TimeSpec)
+timers = unsafePerformIO $! Ref.newIORef Map.empty
+
+{-# NOINLINE readTimer #-}
+readTimer :: String -> Integer
+readTimer name = unsafePerformIO $ do
+    now  <- getTime Monotonic
+    time <- Map.lookup name <$> Ref.readIORef timers
+    case time of
+        Nothing -> error $ "Attempting to read the timer '" ++ name ++ "' that has not been started"
+        Just t  -> return $! timeSpecAsNanoSecs (diffTimeSpec now t)
+
+-- | Initializes the timer store. This makes the first measurement more reliable."
+initializeTimers :: IO ()
+initializeTimers = void $! Ref.readIORef timers
+
+-- | Ties the evaluation of the value with the start of a timer with the given name.
+startTimer :: String -> a -> a
+startTimer name x = start `seq` x where
+    start = unsafePerformIO $ do
+        time <- getTime Monotonic
+        Ref.modifyIORef' timers (Map.insert name time)
+
+-- | Ties the evaluation of the value with an action tracing the elapsed time
+--   since the start of the timer.
+traceTimer :: String -> a -> a
+traceTimer name = trace (format (readTimer name))
+    where format time = "Timer " ++ name ++ ": " ++ asSeconds time ++ " seconds."
+          asSeconds time = showFFloat Nothing (fromIntegral time / 1000000000 :: Double) ""
+
+-- | Synonym for startTimer.
+restartTimer :: String -> a -> a
+restartTimer = startTimer

@@ -0,0 +1,24 @@+module Main where
+
+import Debug.Time
+
+-- | Naive implementation
+fibs :: [Int]
+fibs = map (fibAt . maybeTimer) [1..]
+    where maybeTimer 10 = startTimer "10-30" 10
+          maybeTimer 30 = traceTimer "10-30" 30
+          maybeTimer 20 = startTimer "20-40" 20
+          maybeTimer 40 = traceTimer "20-40" 40
+          maybeTimer n  = n
+
+fibAt :: Int -> Int
+fibAt 1 = 1
+fibAt 2 = 1
+fibAt n = fibAt (n - 1) + fibAt (n - 2)
+
+main :: IO ()
+main = do
+    initializeTimers
+    putStrLn "Calculating the first 40 fibonacci numbers while tracing the time elapsed between"
+    putStrLn "the computations 10-30 and 20-40"
+    mapM_ print (take 40 fibs)