diff --git a/Math/Statistics.hs b/Math/Statistics.hs --- a/Math/Statistics.hs +++ b/Math/Statistics.hs @@ -4,7 +4,7 @@ -- Copyright : (c) Johan Tibell 2008 -- License : BSD3-style (see LICENSE) -- --- Maintainer : johan.tibell@gmail.com +-- Maintainer : me@willsewell.com -- Stability : experimental -- Portability : portable -- @@ -27,7 +27,7 @@ where go :: Floating a => a -> Int -> [a] -> a go m _ [] = m - go m n (x:xs) = go (m + (x - m) / (fromIntegral $ n + 1)) (n + 1) xs + go m n (x:xs) = go (m + (x - m) / fromIntegral (n + 1)) (n + 1) xs -- | Median. median :: (Floating a, Ord a) => [a] -> a @@ -45,11 +45,11 @@ -- | Numerically stable sample variance. variance :: Floating a => [a] -> a -variance xs = (go 0 0 0 xs) / (fromIntegral $ length xs - 1) +variance xs = go 0 0 0 xs / fromIntegral (length xs - 1) where go :: Floating a => a -> Int -> a -> [a] -> a go _ _ s [] = s go m n s (x:xs') = go nm (n + 1) (s + delta * (x - nm)) xs' where delta = x - m - nm = m + delta / (fromIntegral $ n + 1) + nm = m + delta / fromIntegral (n + 1) diff --git a/Test/BenchPress.hs b/Test/BenchPress.hs --- a/Test/BenchPress.hs +++ b/Test/BenchPress.hs @@ -4,7 +4,7 @@ -- Copyright : (c) Johan Tibell 2008 -- License : BSD3-style (see LICENSE) -- --- Maintainer : johan.tibell@gmail.com +-- Maintainer : me@willsewell.com -- Stability : experimental -- Portability : portable -- @@ -15,6 +15,7 @@ -- -- Here's an example showing a benchmark of copying a file: -- +-- > import Control.Monad (when) -- > import qualified Data.ByteString as B -- > import System.IO -- > import Test.BenchPress @@ -32,9 +33,8 @@ -- > go = do -- > bs <- B.hGet inf blockSize -- > let numRead = B.length bs --- > if numRead > 0 --- > then B.hPut outf bs >> go --- > else return () +-- > when (numRead > 0) $ +-- > B.hPut outf bs >> go -- > -- > main :: IO () -- > main = bench 100 $ do @@ -73,8 +73,6 @@ -- --------------------------------------------------------------------- -- Running a benchmark --- TODO: Make sure that iters is > 0. - -- | @benchmark iters setup teardown action@ runs @action@ @iters@ -- times measuring the execution time of each run. @setup@ and -- @teardown@ are run before and after each run respectively. @@ -82,27 +80,30 @@ -- statistics for both the measured CPU times and wall clock times, in -- that order. benchmark :: Int -> IO a -> (a -> IO b) -> (a -> IO c) -> IO (Stats, Stats) -benchmark iters setup teardown action = do - (cpuTimes, wallTimes) <- unzip `fmap` go iters - let xs = sort cpuTimes - cpuStats = Stats - { min = head xs - , mean = Math.mean xs - , stddev = Math.stddev xs - , median = Math.median xs - , max = last xs - , percentiles = percentiles' xs - } - ys = sort wallTimes - wallStats = Stats - { min = head ys - , mean = Math.mean ys - , stddev = Math.stddev ys - , median = Math.median ys - , max = last ys - , percentiles = percentiles' ys - } - return (cpuStats, wallStats) +benchmark iters setup teardown action = + if iters < 1 + then error "benchmark: iters must be greater than 0" + else do + (cpuTimes, wallTimes) <- unzip `fmap` go iters + let xs = sort cpuTimes + cpuStats = Stats + { min = head xs + , mean = Math.mean xs + , stddev = Math.stddev xs + , median = Math.median xs + , max = last xs + , percentiles = percentiles' xs + } + ys = sort wallTimes + wallStats = Stats + { min = head ys + , mean = Math.mean ys + , stddev = Math.stddev ys + , median = Math.median ys + , max = last ys + , percentiles = percentiles' ys + } + return (cpuStats, wallStats) where go 0 = return [] go n = do @@ -176,7 +177,7 @@ putStrLn "Percentiles (ms)" putStr psTbl where - columns = map $ \(p, value) -> printf " %3d%% %5.3f" p value + columns = map (uncurry $ printf " %3d%% %5.3f") colWidth = columnWidth [stats] psTbl = unlines $ columns (percentiles stats) @@ -222,7 +223,7 @@ printSummaryHeader :: Int -> Int -> IO () printSummaryHeader lblLen colWidth = do putStrLn "Times (ms)" - putStr $ (replicate lblLen ' ') ++ " " + putStr $ replicate lblLen ' ' ++ " " putStrLn $ intercalate " " $ map (padHeader colWidth) headers -- | Print a row showing a summary of the given stats. @@ -237,7 +238,7 @@ -- | Compute percentiles given a list of execution times in ascending -- order. percentiles' :: [Double] -> [(Int, Double)] -percentiles' xs = zipWith (\p ys -> (p, ys !! (rank p))) ps (repeat xs) +percentiles' xs = map (\p -> (p, xs !! rank p)) ps where n = length xs rank p = ceiling ((fromIntegral n / 100) * fromIntegral p :: Double) - 1 diff --git a/benchpress.cabal b/benchpress.cabal --- a/benchpress.cabal +++ b/benchpress.cabal @@ -1,5 +1,5 @@ name: benchpress -version: 0.2.2.7 +version: 0.2.2.8 synopsis: Micro-benchmarking with detailed statistics. Description: Benchmarks actions and produces statistics such as min, mean, median, standard deviation, @@ -20,8 +20,21 @@ other-modules: Math.Statistics - build-depends: base >= 2.0 && < 4.9, + build-depends: base >= 2.0 && < 4.10, mtl >= 1 && < 2.3, - time >= 1 && < 1.6 + time >= 1 && < 1.7 + + ghc-options: -funbox-strict-fields -Wall + +executable example + main-is: Main.hs + + -- This is not in build-depends for cabal 1.2 compatibility (requires 1.8) + other-modules: Test.BenchPress + + hs-source-dirs: example, . + + build-depends: base, + bytestring ghc-options: -funbox-strict-fields -Wall diff --git a/example/Main.hs b/example/Main.hs new file mode 100644 --- /dev/null +++ b/example/Main.hs @@ -0,0 +1,28 @@ +import Control.Monad (when) +import qualified Data.ByteString as B +import System.IO +import Test.BenchPress + +inpath, outpath :: String +inpath = "/tmp/infile" +outpath = "/tmp/outfile" + +blockSize :: Int +blockSize = 4 * 1024 + +copyUsingByteString :: Handle -> Handle -> IO () +copyUsingByteString inf outf = go + where + go = do + bs <- B.hGet inf blockSize + let numRead = B.length bs + when (numRead > 0) $ + B.hPut outf bs >> go + +main :: IO () +main = bench 100 $ do + inf <- openBinaryFile inpath ReadMode + outf <- openBinaryFile outpath WriteMode + copyUsingByteString inf outf + hClose outf + hClose inf