UUoCのベンチマークです。 https://ja.stackoverflow.com/questions/34214

0-UUoC-Benchmark.md

実験環境

• Intel Core i7-7500U CPU @ 2.70 GHz クアッドコア
• メモリ 16GB
• Ubuntu 16.10 yakkety (x86_64, 4.8.0-46-generic)
• GNU bash 4.3.46(1)-release (x86_64-pc-linux-gnu)
• grep (GNU grep) 2.25
• cat (GNU coreutils) 8.25
• go version go1.8 linux/amd64

log

# 改行があるテキストファイルの場合のログ
Size	grep a FILE	cat FILE | grep a
1	1628986.050000	2277017.950000
5	1371493.850000	1866161.350000
10	1330203.100000	1663005.050000
50	1336509.300000	1693194.800000
100	1371718.000000	1811099.450000
500	1456991.150000	1917038.800000
1024	1543473.000000	2094624.000000
5120	2423058.550000	3364557.450000
10240	3218446.000000	4969714.750000
51200	11629891.200000	18146762.950000
102400	22254559.750000	34036223.300000
512000	100217975.550000	160507865.500000
1048576	180088340.850000	320137904.100000
5242880	857794564.150000	1545226725.900000
10485760	2886427989.250000	3202013808.850000

log-binary

# バイナリファイルの場合のログ
Size	grep a FILE	cat FILE | grep a
1	1581347.050000	1775962.650000
5	1318343.850000	1761388.000000
10	1200220.150000	1554791.000000
50	1245887.950000	1578335.350000
100	1287939.950000	1702699.150000
500	1524866.950000	1842490.650000
1024	1859444.100000	2228896.900000
5120	3996075.150000	4256021.300000
10240	6442738.800000	6835296.600000
51200	25735508.400000	27734911.800000
102400	50883223.100000	52917631.950000
512000	246976414.400000	265936897.700000
1048576	504907376.700000	565962037.050000
5242880	2521654671.250000	2848791126.000000
10485760	5250627603.900000	5524435772.300000

log-redirection

# 改行があるテキストファイルについて、<FILENAME grep a についても同様にベンチマークをとってみたログ
Size	<FILENAME grep a
1	2125799.150000
5	1830172.500000
10	1370422.950000
50	1421713.500000
100	1487108.450000
500	1606865.500000
1024	1631634.950000
5120	2442890.650000
10240	3453758.200000
51200	12332587.350000
102400	20900270.400000
512000	90421090.200000
1048576	194268279.050000
5242880	884363476.950000
10485760	3099899414.700000

log-without-newline

# 改行が無いテキストファイルの場合のログ
Size	grep a FILE	cat FILE | grep a
1	1562107.050000	1911358.450000
5	1435588.650000	2015130.550000
10	1283699.150000	1560620.800000
50	1287053.950000	1629947.300000
100	1330382.350000	1635569.650000
500	1880728.450000	2145010.250000
1024	2600131.250000	3162551.900000
5120	7538146.500000	11759352.200000
10240	12450896.600000	31949892.750000
51200	46581310.000000	506808350.150000
102400	89835399.050000	1984445186.600000
512000	489720105.050000	46670393357.750000
1048576	1133701684.900000	195539025232.200012

main.go

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"syscall"
	"time"
)

const KB int64 = 1
const MB int64 = 1024
const GB int64 = 1024 * 1024

func main() {
	fmt.Printf("Size\tgrep a FILE\tcat FILE | grep a\n")

	sizes := []int64{1 * KB, 5 * KB, 10 * KB, 50 * KB, 100 * KB, 500 * KB,
		1 * MB, 5 * MB, 10 * MB, 50 * MB, 100 * MB, 500 * MB,
		1 * GB, 5 * GB, 10 * GB}
	n := 10
	for _, size := range sizes {
		benchmark(size, n)
	}
}

func benchmark(size int64, n int) {
	// 指定サイズのファイルを作る
	bigFile, err := ioutil.TempFile("", "")
	if err != nil {
		log.Fatal(err)
	}
	bigFileName := bigFile.Name()
	defer func() {
		err := os.Remove(bigFileName)
		if err != nil {
			log.Fatal(err)
		}
	}()
	/*
		if err := bigFile.Truncate(size * 1024); err != nil {
			log.Fatal(err)
		}
	*/
	// ここでベンチマークの種類を変えます
	fillZero(bigFile, size)

	// 2*n 回時間計測して平均をとる
	var timeSum1 time.Duration = 0
	var timeSum2 time.Duration = 0
	timeSum1 += execLoop(n, grep1, bigFileName)
	timeSum2 += execLoop(n, grep2, bigFileName)
	timeSum2 += execLoop(n, grep2, bigFileName)
	timeSum1 += execLoop(n, grep1, bigFileName)

	// 出力
	fmt.Printf("%d\t%f\t%f\n", size,
		float64(timeSum1)*0.5/float64(n),
		float64(timeSum2)*0.5/float64(n))
}

func fillZero(file *os.File, size int64) {
	b := make([]byte, 1024)
	for i, _ := range b {
		b[i] = '0'
	}
	for i := int64(0); i < size; i++ {
		_, err := file.Write(b)
		if err != nil {
			// TODO
			log.Fatal(err)
		}
	}
}

func fillZeroWithNewline(file *os.File, size int64) {
	b := make([]byte, 1024)
	for i := 0; i < 1023; i++ {
		b[i] = '0'
	}
	b[1023] = '\n'
	for i := int64(0); i < size; i++ {
		_, err := file.Write(b)
		if err != nil {
			// TODO
			log.Fatal(err)
		}
	}
}

func fillNull(file *os.File, size int64) {
	b := make([]byte, 1024)
	for i, _ := range b {
		b[i] = 0x0
	}
	for i := int64(0); i < size; i++ {
		_, err := file.Write(b)
		if err != nil {
			// TODO
			log.Fatal(err)
		}
	}
}

// grep を n 回ループする時間を測る
func execLoop(n int, grep func(string) string, bigFileName string) time.Duration {
	var timeSum time.Duration = 0
	for i := 0; i < n; i++ {
		command := exec.Command("bash", "-c", grep(bigFileName))
		start := time.Now()
		err := command.Run()
		timeSum += time.Since(start)
		if err != nil {
			if exitErr, ok := err.(*exec.ExitError); ok {
				if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
					if status.ExitStatus() != 1 {
						log.Fatal(err)
					}
				} else {
					log.Fatalf("exitErr.Sys().(syscall.WaitStatus) failed")
				}
			} else {
				log.Fatal(err)
			}
		}
	}
	return timeSum
}

// grep a FILENAME
func grep1(fileName string) string {
	return "grep a \"" + fileName + "\""
}

// cat FILENAME | grep a
func grep2(fileName string) string {
	return "cat \"" + fileName + "\" | grep a"
}

plot.plt

set terminal png font "MigMix 2M,14"
set title "Useless Use of Catによる実行速度変化 (改行あり)"
set xlabel "テキストファイルのサイズ [KB]"
set ylabel "時間 [秒]"
set key left top
set output "UUoC.png"
set logscale x 10
set logscale y 10
set format x "%.0t{/Symbol \264}10^{%T}"
set format y "%.0t{/Symbol \264}10^{%T}"
set xtics rotate by -70
plot "log" using 1:($2 / 1000000000) title "grep a FILENAME", \
     "log" using 1:($3 / 1000000000) title "cat FILENAME | grep a"