相同逻辑的php与golang代码效率对比，最好语言落谁家…

100人浏览 2024-09-04 09:02:53

业务逻辑：

逐行读取一个3.6MB的文件，

把每行的字符串切割成数组，

计算二维数组中的经纬度值与目标地点的经纬度的距离，

符合限定距离范围的结果存入map中，

将结果覆盖写入一个新的文件，

计算程序执行的时间。

php版：

<?php
$stime=microtime(true);

const BJ_LAT = 39.9041999;
const BJ_LNG = 116.4073963;
const DISTANCE = 100;

$handle = fopen('air_route_data.txt','rb+');
$result = [];
while(!feof($handle)){
    $lines = fgets($handle);
    $airRoute = explode(' ',$lines);
    $lat = (float)$airRoute[3];
    $lng = (float)str_replace(array("\r\n", "\r", "\n"), "", $airRoute[4]);
    $distance = getDistance($lat,$lng);
    if ($distance <= DISTANCE){
        $result[$airRoute[2]] = ['lat'=>$lat,'lng'=>$lng ];
    }
}
fclose($handle);

$jsonString = json_encode($result,JSON_UNESCAPED_UNICODE);

file_put_contents('bjs_route_data.txt',$jsonString);
//$handle2 = fopen('bjs_route_data.txt',"w+");
//fwrite($handle2,$jsonString);
//fclose($handle2);

$etime=microtime(true);
$total=$etime-$stime;   //计算差值
//echo "当前页面执行时间为：{$total} 秒";
$ms = $total*1000;
echo "当前页面执行时间为：{$ms} 毫秒";

function getDistance($lat1, $lng1, $lat2=39.9041999, $lng2=116.4073963)
{
    $EARTH_RADIUS = 6378.137;

    $radLat1 = rad($lat1);
    $radLat2 = rad($lat2);
    $a = $radLat1 - $radLat2;
    $b = rad($lng1) - rad($lng2);
    $s = 2 * asin(sqrt(pow(sin($a / 2), 2) + cos($radLat1) * cos($radLat2) * pow(sin($b / 2), 2)));
    $s = $s * $EARTH_RADIUS;
    $s = round($s * 100) / 100;

    return $s;
}

function rad($d)
{
    return $d * M_PI / 180.0;
}

没有启动nginx，走php-fpm，直接从命令行执行的。

php执行时间：

测试N次，大约在116ms左右

go版：

package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
	"strings"
	"time"
)

//北京经纬度
const BJ_LAT = 39.9041999
const BJ_LNG = 116.4073963
const DISTANCE = 100

type Location struct {
	Lat float64 `json:"lat"`
	Lng float64 `json:"lng"`
}
func main() {
	t := time.Now()

	fi, err := os.Open("air_route_data.txt")
	if err != nil {
		fmt.Printf("Error: %s\n", err)
		return
	}
	defer fi.Close()

	result := make(map[string]*Location)
	//result := make(map[string]Location)

	br := bufio.NewReader(fi)
	for {
		data, _, c := br.ReadLine()
		if c == io.EOF {
			break
		} 
		airRoute := strings.Fields(string(data))
		lat,_ := strconv.ParseFloat(airRoute[3],64)
		lng , _ := strconv.ParseFloat(airRoute[4],64) 
		if lng < 0 || lat < 0 {
			continue
		}

		distance := GetDistance(lat,lng , BJ_LAT,BJ_LNG)
		if distance <= DISTANCE {
			//写数据
			temp := new(Location)
			temp.Lat = lat
			temp.Lng = lng
			result[airRoute[2]] = temp
			//result[airRoute[2]] = Location{lat,lng}
		}
	}
	//写文件
	jsonString, _ := json.Marshal(result)

	f, _ := os.OpenFile("bjs_route_data.txt", os.O_TRUNC | os.O_WRONLY , 0666) //打开文件

	io.WriteString(f,string(jsonString))
	defer f.Close() 

	elapsed := time.Since(t)
	fmt.Println("当前页面执行时间为:", elapsed)

}

// 返回单位，千米
func GetDistance(lon1, lat1, lon2, lat2 float64) (distance float64) {
	//赤道半径(单位m)
	const EARTH_RADIUS = 6378.137
	rad_lat1 := rad(lat1)
	rad_lon1 := rad(lon1)
	rad_lat2 := rad(lat2)
	rad_lon2 := rad(lon2)
	if rad_lat1 < 0 {
		rad_lat1 = math.Pi/2 + math.Abs(rad_lat1)
	}
	if rad_lat1 > 0 {
		rad_lat1 = math.Pi/2 - math.Abs(rad_lat1)
	}
	if rad_lon1 < 0 {
		rad_lon1 = math.Pi*2 - math.Abs(rad_lon1)
	}
	if rad_lat2 < 0 {
		rad_lat2 = math.Pi/2 + math.Abs(rad_lat2)
	}
	if rad_lat2 > 0 {
		rad_lat2 = math.Pi/2 - math.Abs(rad_lat2)
	}
	if rad_lon2 < 0 {
		rad_lon2 = math.Pi*2 - math.Abs(rad_lon2)
	}
	x1 := EARTH_RADIUS * math.Cos(rad_lon1) * math.Sin(rad_lat1)
	y1 := EARTH_RADIUS * math.Sin(rad_lon1) * math.Sin(rad_lat1)
	z1 := EARTH_RADIUS * math.Cos(rad_lat1)

	x2 := EARTH_RADIUS * math.Cos(rad_lon2) * math.Sin(rad_lat2)
	y2 := EARTH_RADIUS * math.Sin(rad_lon2) * math.Sin(rad_lat2)
	z2 := EARTH_RADIUS * math.Cos(rad_lat2)
	d := math.Sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2) + (z1-z2)*(z1-z2))
	theta := math.Acos((EARTH_RADIUS*EARTH_RADIUS + EARTH_RADIUS*EARTH_RADIUS - d*d) / (2 * EARTH_RADIUS * EARTH_RADIUS))
	distance = theta * EARTH_RADIUS
	return
}

//转化为弧度(rad)
func rad(d float64) (r float64) {
	r = d * math.Pi / 180.0
	return
}