func()

in oss/lib/cp.go [2490:2551]
51 lines of code
12 McCabe index (conditional complexity)

func (cc *CopyCommand) downloadSingleFile(bucket *oss.Bucket, objectInfo objectInfoType, filePath string) (bool, error, int64, string) {
	//get object size and last modify time
	object := objectInfo.prefix + objectInfo.relativeKey
	size := objectInfo.size
	srct := objectInfo.lastModified
	//make file name
	fileName := cc.makeFileName(objectInfo.relativeKey, filePath)
	msg := fmt.Sprintf("%s %s to %s", opDownload, CloudURLToString(bucket.BucketName, object), fileName)

	if size < 0 {
		statOptions := cc.cpOption.payerOptions
		if cc.cpOption.versionId != "" {
			statOptions = append(statOptions, oss.VersionId(cc.cpOption.versionId))
		}
		props, err := cc.command.ossGetObjectStatRetry(bucket, object, statOptions...)
		if err != nil {
			return false, err, size, msg
		}
		size, err = strconv.ParseInt(props.Get(oss.HTTPHeaderContentLength), 10, 64)
		if err != nil {
			return false, err, size, msg
		}
		if srct, err = time.Parse(http.TimeFormat, props.Get(oss.HTTPHeaderLastModified)); err != nil {
			return false, err, size, msg
		}
	}

	rsize := cc.getRangeSize(size)
	if cc.skipDownload(fileName, srct, CloudURLToString(bucket.BucketName, object)) {
		return true, nil, rsize, msg
	}

	if size == 0 && strings.HasSuffix(object, "/") {
		return false, os.MkdirAll(fileName, 0755), rsize, msg
	}

	//create parent directory
	if err := cc.createParentDirectory(fileName); err != nil {
		return false, err, rsize, msg
	}

	downloadOptions := cc.cpOption.options
	if cc.cpOption.vrange != "" {
		downloadOptions = append(downloadOptions, oss.NormalizedRange(cc.cpOption.vrange))
	}

	if rsize < cc.cpOption.threshold {
		var listener *OssProgressListener = &OssProgressListener{&cc.monitor, 0, 0, false}
		downloadOptions = append(downloadOptions, oss.Progress(listener))
		return false, cc.ossDownloadFileRetry(bucket, object, fileName, downloadOptions...), 0, msg
	}

	var listener *OssResumeProgressListener = &OssResumeProgressListener{&cc.monitor, 0, 0, false, false}
	downloadOptions = append(downloadOptions, oss.Progress(listener))

	partSize, rt := cc.preparePartOption(size)
	cp := oss.CheckpointDir(true, cc.cpOption.cpDir)
	LogInfo("multipart download,object %s,file size:%d,partSize %d,routin count:%d,checkpoint dir:%s\n",
		object, size, partSize, rt, cc.cpOption.cpDir)
	downloadOptions = append(downloadOptions, oss.Routines(rt), cp)
	return false, cc.ossResumeDownloadRetry(bucket, object, fileName, size, partSize, downloadOptions...), 0, msg
}