Go 设计模式“金旋风”——代理模式

package main
import "fmt"
type Movie struct {  name   string  cached bool}
type BilibiliDownloaderAPI interface {  DownloadMovie(m *Movie)}
type BilibiliDownloader struct {  BilibiliDownloaderAPI}
func (b *BilibiliDownloader) DownloadMovie(m *Movie) {  fmt.Println("下载视频中" + m.name + "...")}
type Proxy struct {  downloaderAPI BilibiliDownloaderAPI}
func CreateProxy(downloaderAPI BilibiliDownloaderAPI) BilibiliDownloaderAPI {  return &Proxy{downloaderAPI}}
func (p *Proxy) DownloadMovie(m *Movie) {  if m.cached == false {    p.downloaderAPI.DownloadMovie(m)    m.cached = true  } else {    p.LoadingCache(m)  }}
func (p *Proxy) LoadingCache(m *Movie) {  fmt.Println("加载" + m.name + "缓存...")}
func main() {  movie := Movie{name: "一只小仓鼠的故事", cached: false}  proxy := CreateProxy(new(BilibiliDownloader))  proxy.DownloadMovie(&movie)  proxy.DownloadMovie(&movie)}