fix: http download size exceeds file size (#959)

pkg/download/downloader.go

@@ -208,7 +208,7 @@ func (d *Downloader) Setup() error {
 						if task.Status == base.DownloadStatusRunning {
 							downloadDataChanged = current != task.Progress.Downloaded
 							task.Progress.Used = task.timer.Used()
-							task.Progress.Speed = task.calcSpeed(task.speedArr, current-task.Progress.Downloaded, tick)
+							task.Progress.Speed = task.updateSpeed(current-task.Progress.Downloaded, tick)
 							task.Progress.Downloaded = current
 						}
 
@@ -217,7 +217,7 @@ func (d *Downloader) Setup() error {
 							uploader := task.fetcher.(fetcher.Uploader)
 							currentUploaded := uploader.UploadedBytes()
 							uploadDataChanged = currentUploaded != task.Progress.Uploaded
-							task.Progress.UploadSpeed = task.calcSpeed(task.uploadSpeedArr, currentUploaded-task.Progress.Uploaded, tick)
+							task.Progress.UploadSpeed = task.updateUploadSpeed(currentUploaded-task.Progress.Uploaded, tick)
 							task.Progress.Uploaded = currentUploaded
 						}
 						d.emit(EventKeyProgress, task)

pkg/download/model.go

@@ -100,16 +100,27 @@ func (t *Task) clone() *Task {
 	return util.DeepClone(t)
 }
 
-func (t *Task) calcSpeed(speedArr []int64, downloaded int64, usedTime float64) int64 {
-	speedArr = append(speedArr, downloaded)
-	if len(speedArr) > 6 {
-		speedArr = speedArr[1:]
+func (t *Task) updateSpeed(downloaded int64, usedTime float64) int64 {
+	return calcSpeed(&t.speedArr, downloaded, usedTime)
+}
+
+func (t *Task) updateUploadSpeed(downloaded int64, usedTime float64) int64 {
+	return calcSpeed(&t.uploadSpeedArr, downloaded, usedTime)
+}
+
+func calcSpeed(speedArr *[]int64, downloaded int64, usedTime float64) int64 {
+	*speedArr = append(*speedArr, downloaded)
+	// Record last 5 seconds of download speed to calculate the average speed
+	if len(*speedArr) > int(5.0/usedTime) {
+		*speedArr = (*speedArr)[1:]
 	}
+
 	var total int64
-	for _, v := range speedArr {
+	for _, v := range *speedArr {
 		total += v
 	}
-	return int64(float64(total) / float64(len(speedArr)) / usedTime)
+
+	return int64(float64(total) / float64(len(*speedArr)) / usedTime)
 }
 
 type TaskFilter struct {