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("", "", ""), "", $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。
go版:
package mainimport ("bufio""encoding/json""fmt""io""math""os""strconv""strings""time")//北京经纬度const BJ_LAT = 39.9041999const BJ_LNG = 116.4073963const DISTANCE = 100type 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", 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 = lattemp.Lng = lngresult[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 = 6378.137rad_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_RADIUSreturn}//转化为弧度(rad)func rad(d float64) (r float64) {r = d * math.Pi / 180.0return}
没有go build或者go install, 直接使用go run执行。
结论:
试验过程中,尽量严谨。去除了nginx,两者没有借助web服务器启动,都是直接执行。
结果是相同的for循环10w+以上的代码逻辑,go的执行效率要比php快一倍以上。
php的一个数组解决一切数据格式问题,变量使用无需定义,数据类型和格式无需严谨,随用随定义等等特点,再加上php的web生态,已有的轮子特别多,这些决定了php做网站开发的速度是非常快的。
缺点是历史上的php4、php5遗留下的不严谨,很多开源代码框架cms有漏洞、效率、可维护等的问题。这些问题在未来的8,应该能更好的解决或者弥补。
但是,php语言本身的定位决定了执行速度的瓶颈。毕竟执行效率比go要慢。