我有这段代码,但我不喜欢那种不提 golint
的感觉,不喜欢 error should be the last type when return multiple items (golint)
。解释这段代码:
- 我想让用户决定他们是否关心返回的任何错误
- 特别是在这段代码中,有时不需要或不需要音频文件,可以忽略它
- 无论用户在做什么,都可能总是需要视频和输出文件
我愿意以任何方式重构它(将其分解、移动等)Go 中是否有更惯用的方式来完成这样的事情?
// Download will download the audio and video files to a particular path
func (r *RedditVideo) Download() (outputVideoFileName string, outputAudioFileName string, errVideo error, errAudio error) {
outputVideoFile, errVideo := downloadTemporaryFile(
r.VideoURL,
TemporaryVideoFilePrefix,
)
if errVideo == nil {
outputVideoFileName = outputVideoFile.Name()
}
outputAudioFile, errAudio := downloadTemporaryFile(
r.AudioURL,
TemporaryAudioFilePrefix,
)
if errAudio == nil {
outputAudioFileName = outputAudioFile.Name()
}
return outputVideoFileName, outputAudioFileName, errVideo, errAudio
}
类似地,我发现自己稍后在代码中再次使用了相同的模式:
// SetFiles sets up all of the input files and the output file
func (l *localVideo) SetFiles(inputVideoFilePath string, inputAudioFilePath string, outputVideoFilePath string) (errVideo error, errAudio error, errOutputVideo error) {
// Set input video file
l.inputVideoFile, errVideo = os.Open(inputVideoFilePath)
if errVideo != nil {
return
}
if errVideo = l.inputVideoFile.Close(); errVideo != nil {
return
}
// Set output video file
l.outputVideoFile, errOutputVideo = os.Create(outputVideoFilePath)
if errOutputVideo != nil {
return
}
if errOutputVideo = l.outputVideoFile.Close(); errOutputVideo != nil {
return
}
// IMPORTANT! Set input audio file LAST incase it is nil
l.inputAudioFile, errAudio = os.Open(inputAudioFilePath)
if errAudio != nil {
return
}
if errAudio = l.inputAudioFile.Close(); errVideo != nil {
return
}
return
}
这次在这段代码中,部分内容与上面相同:
- 我们关心视频和输出的设置,可能关心也可能不关心音频
- 有多个错误需要由用户处理
最佳答案
您在标准库中可以看到很多特定函数,它们包装了更通用的非导出函数。请参阅下面的注释代码。
// download is a rather generic function
// and probably you can refactor downloadTemporaryFile
// so that even this function is not needed any more.
func (r *RedditVideo) download(prefix, url string) (filename string, error error) {
outputFile, err := downloadTemporaryFile(
r.VideoURL,
prefix,
)
if err == nil {
return "", fmt.Errorf("Error while download: %s", err)
}
return outputFile.Name(), nil
}
// DownloadVideo wraps download, handing over the values specific
// to the video download
func (r *RedditVideo) DownloadVideo() (filename string, averror error) {
return r.download(TemporaryVideoFilePrefix, r.VideoURL)
}
// DownloadAudio wraps download, handing over the values specific
// to the audio download
func (r *RedditVideo) DownloadAudio() (filename string, averror error) {
return r.download(TemporaryAudioFilePrefix, r.AudioURL)
}
func main() {
r := RedditVideo{
VideoURL: os.Args[1],
AudioURL: os.Args[2],
}
var videoerror, audioerror error
var videofileName, audiofileName string
if videofileName, videoerror = r.DownloadVideo(); videoerror != nil {
fmt.Println("Got an error downloading the video")
}
if audiofileName, audioerror = r.DownloadAudio(); audioerror != nil {
fmt.Println("Got an error downloading the audio")
}
fmt.Printf("Video:\t%s\nAudio:\t%s", videofileName, audiofileName)
}
这样一来,返回的错误来自于哪个下载就一目了然了。
关于go - 返回多个错误或相应地处理它们的惯用方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53858609/