c && c++ && go && luajit性能对比

总结：

• luajit性能略逊于go性能
• c/c++ 性能是go的3~4倍

一、字符串查找性能比较

luajit

begin = os.clock();
str = "Hello! My name is Jack. What is your name?"
i = 0
while i <= 500000000 do
    string.find(str,"Jack")
    i=i+1;
end
print('The program use ', os.clock()-begin, 's');

结果

root@fanpf-VirtualBox:/usr/local/openresty/luajit/bin# ./luajit pfm.lua
The program use 	0.544375	s

耗时：0.544375

C && CPP

#include <string>
#include <chrono>
#include <iostream>

#include <string.h>
#include <time.h>
#include <stdio.h>
#include <unistd.h>

using namespace std;

void test_c(size_t count)
{
	char str1[] = "Hello! My name is Jack. What is your name?";
	char str2[] = "Jack";
	time_t begin, over;
	char *pos;

	size_t i = 0;
	time(&begin);
	while (i <= count) {
		pos = strstr(str1,str2);
		i++;
	}
	time(&over);
	printf("%s:The program use %lu s \n", __func__,  over - begin);
}

void test_cpp_strfind(size_t count)
{
	string str1 = "Hello! My name is Jack. What is your name?";
	string str2 = "Jack";
	time_t end, start = chrono::system_clock::to_time_t(chrono::system_clock::now());
	size_t i = 0;
	while (i <= count) {
		str1.find(str2);
		i++;
	}
	end = chrono::system_clock::to_time_t(chrono::system_clock::now());
	printf("%s: The program use %d s \n", __func__, static_cast<int>(end - start));
}

void test_cpp_strview_find(size_t count)
{
	string_view str1 = "Hello! My name is Jack. What is your name?";
	string_view str2 = "Jack";
	time_t end, start = chrono::system_clock::to_time_t(chrono::system_clock::now());
	size_t i = 0;
	while (i <= count) {
		str1.find(str2);
		i++;
	}
	end = chrono::system_clock::to_time_t(chrono::system_clock::now());
	printf("%s: The program use %d s \n", __func__, static_cast<int>(end - start));
}

void test_cpp_strstr(size_t count)
{
	string str1 = "Hello! My name is Jack. What is your name?";
	string str2 = "Jack";
	time_t start = chrono::system_clock::to_time_t(chrono::system_clock::now());
	size_t i = 0;
	while (i <= count) {
		strstr(str1.c_str(),str2.c_str());
		i++;
	}
	time_t end = chrono::system_clock::to_time_t(chrono::system_clock::now());
	printf("%s The program use %d s \n", __func__, static_cast<int>(end - start));
}


int main()
{
	size_t count = 500000000;

	test_c(count);
	test_cpp_strstr(count);
	test_cpp_strfind(count);
	test_cpp_strview_find(count);

	return 0;
}
	int i = 0;
	time(&begin);
	while (i <= count) {
		strstr(str1,str2);
		i++;
	}
	time(&over);
	printf("%s:The program use %d s \n", __func__,  (int)(over - begin));
}

void test_cpp_strfind(int count)
{
	string str1 = "Hello! My name is Jack. What is your name?";
	string str2 = "Jack";
	time_t end, start = chrono::system_clock::to_time_t(chrono::system_clock::now());
	int i = 0;
	while (i <= count) {
		str1.find(str2);
		i++;
	}
	end = chrono::system_clock::to_time_t(chrono::system_clock::now());
	printf("%s: The program use %d s \n", __func__, static_cast<int>(end - start));
}

void test_cpp_strstr(int count)
{
	string str1 = "Hello! My name is Jack. What is your name?";
	string str2 = "Jack";
	time_t start = chrono::system_clock::to_time_t(chrono::system_clock::now());
	int i = 0;
	while (i <= count) {
		strstr(str1.c_str(),str2.c_str());
		i++;
	}
	time_t end = chrono::system_clock::to_time_t(chrono::system_clock::now());
	printf("%s The program use %d s \n", __func__, static_cast<int>(end - start));
}


int main()
{
	int count = 500000000;
	test_c(count);
	test_cpp_strstr(count);
	test_cpp_strfind(count);
/*
test_c:The program use 1 s
test_cpp_strstr The program use 8 s
test_cpp_strfind: The program use 10 s
*/
	return 0;
}

不使用-O2 结果

使用-O2后的执行结果：

test_c:The program use 0 s
test_cpp_strstr The program use 0 s
test_cpp_strfind: The program use 9 s
test_cpp_strview_find: The program use 0 s

stringview效率比string高很多，-O2选项提高运行效率

golang

package main

import (
	"fmt"
	"strings"
	"time"
)

func main() {
	count := 500000000
	str1 := "Hello! My name is Jack. What is your name?"
	str2 := "Jack"
	start := time.Now().UnixNano()

	for i := 0; i <= count; i++ {
		strings.Contains(str1, str2)
	}

	end := time.Now().UnixNano()
	fmt.Println("use:\n", (end-start)/1000)
}

结果： 用时4s

字符串测试总结：

• c耗时：0秒
• cpp + strstr耗时： 0秒
• cpp + stringview: 0秒
• luajit耗时：0.544375秒
• go耗时：4秒
• cpp string耗时：9秒

Fibonacci测试

lua

--递归
local function Fibonacci_1(n)
	if n == 1 or n == 2 then
		return 1
	else
		return Fibonacci_1(n - 1) + Fibonacci_1(n - 2)
	end
end

Fibonacci_1(45)

root@fanpf-VirtualBox:/usr/local/openresty/luajit/bin/fib# time ../luajit fib.lua

real 0m7,219s

user 0m7,231s

sys 0m0,000s

c

#include <stdio.h>

int fibonacci(int i){
	if(i<2) return i;
	return fibonacci(i-2) + fibonacci(i-1);
}
int main(){
	printf("%d",fibonacci(45));
}

real	0m1,823s

cpp

#include <iostream>

constexpr int fibonacci(const int i){
	if(i<2) return i;
	return fibonacci(i-2) + fibonacci(i-1);
}

int main() {
	fibonacci(45);
	return 0;
}

real 0m1,536s

go

package main
import "fmt"
func main(){
	fmt.Println(fibonacci(45))
}
func fibonacci(i int) int{
	if(i<2){
		return i;
	}
	return fibonacci(i-2) + fibonacci(i-1);
}

real 0m6,517s

fib计算总结：cpp最快， lua最慢

• cpp：0m1,536s
• C: 0m1,823s
• go：0m6,517s
• luajit：0m7,219s