下载带进度条

library/http/http_client.go

 package http
 
 import (
+	"fmt"
 	"io"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/gogf/gf/frame/g"
@@ -21,8 +23,47 @@ func handle(response *ghttp.ClientResponse, err error) ([]byte, error) {
 	return response.ReadAll(), nil
 }
 
+type WriteCounter struct {
+	Total uint64
+}
+
+func (wc *WriteCounter) Write(p []byte) (int, error) {
+	n := len(p)
+	wc.Total += uint64(n)
+	wc.PrintProgress()
+	return n, nil
+}
+
+func (wc WriteCounter) PrintProgress() {
+	// Clear the line by using a character return to go back to the start and remove
+	// the remaining characters by filling it with spaces
+	fmt.Printf("\r%s", strings.Repeat(" ", 35))
+
+	// Return again and print current status of download
+	// We use the humanize package to print the bytes in a meaningful way (e.g. 10 MB)
+	fmt.Printf("\rDownloading... %s  complete", wc.formatFileSize(wc.Total))
+}
+
+func (wc WriteCounter) formatFileSize(fileSize uint64)  string {
+	if fileSize < 1024 {
+		//return strconv.FormatInt(fileSize, 10) + "B"
+		return fmt.Sprintf("%.2fB", float64(fileSize)/float64(1))
+	} else if fileSize < (1024 * 1024) {
+		return fmt.Sprintf("%.2fKB", float64(fileSize)/float64(1024))
+	} else if fileSize < (1024 * 1024 * 1024) {
+		return fmt.Sprintf("%.2fMB", float64(fileSize)/float64(1024*1024))
+	} else if fileSize < (1024 * 1024 * 1024 * 1024) {
+		return fmt.Sprintf("%.2fGB", float64(fileSize)/float64(1024*1024*1024))
+	} else if fileSize < (1024 * 1024 * 1024 * 1024 * 1024) {
+		return fmt.Sprintf("%.2fTB", float64(fileSize)/float64(1024*1024*1024*1024))
+	} else { //if fileSize < (1024 * 1024 * 1024 * 1024 * 1024 * 1024)
+		return fmt.Sprintf("%.2fEB", float64(fileSize)/float64(1024*1024*1024*1024*1024))
+	}
+}
+
 // 下载文件
 func Download(file string, path string) error {
+	g.Log().Async().Infof("Download File: %s", path)
 	resp, err := g.Client().Get(file)
 
 	if err != nil {
@@ -35,10 +76,13 @@ func Download(file string, path string) error {
 	if err != nil {
 		return err
 	}
+
+
 	defer out.Close()
 
 	// 然后将响应流和文件流对接起来
-	_, err = io.Copy(out, resp.Body)
+	counter := &WriteCounter{}
+	_, err = io.Copy(out, io.TeeReader(resp.Body, counter))
 
 	if err != nil && err == io.EOF {
 		return nil
@@ -46,5 +90,6 @@ func Download(file string, path string) error {
 	if err != nil {
 		return err
 	}
+	fmt.Print("\n")
 	return nil
 }