speed test for github.com/nfnt/resize.

resize.go

package main

import (
	"github.com/nfnt/resize"
	"os"
	"path/filepath"
	"image"
	"image/jpeg"
	"log"
	"errors"
	"flag"
	"time"
)


func main() {
	flag.Parse()
	file := flag.Arg(0)

	tpath := []string{"1.jpg", "2.jpg"}
	size := []image.Point{{100,0}, {600,0}}

	start := time.Now()
	ResizeImg(file, tpath, size)
	end := time.Now()
	println("time consumed: ", end.Sub(start))
}


func ResizeImg(spath string, tpath []string, size []image.Point) (int, error) {

	if len(tpath) != len(size) {
		log.Println("GetImgThumb: ", tpath, size)
		return 0, errors.New("GetImgThumb length unsafe")
	}

	file, err := os.Open(spath)
	if err != nil {
		return 0, err
	}
	img, err := jpeg.Decode(file)
	if err != nil {
		log.Println(err)
		return 0, err
	}
	file.Close()
	
	cnt := 0
	for i, tgt := range tpath {
		_, err := os.Stat(tgt)
		if err != nil {
			if !os.IsNotExist(err) {
				log.Println(err)
				continue
			}
			// 创建文件夹
			os.MkdirAll(filepath.Dir(tgt), 0755)

			m1 := time.Now()
			m := resize.Resize(uint(size[i].X), uint(size[i].Y), img, resize.NearestNeighbor)
			m2 := time.Now()
			println("time consumed sub: ", i,  m2.Sub(m1))
			
			out, err := os.Create(tgt)
			if err != nil {
				log.Println(err)
				continue
			}

			// write new image to file
			jpeg.Encode(out, m, nil)
			out.Close()
			cnt++
		}
	}
	return cnt, nil
}