mirror of
https://gitee.com/XM-GO/PandaX.git
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133 lines
2.4 KiB
Go
133 lines
2.4 KiB
Go
package utilFile
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import (
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"io"
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"mime/multipart"
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"net/http"
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"os"
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"pandax/kit/biz"
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"strconv"
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"sync"
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)
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const (
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MaxConcurrency = 16 // 最大并发数
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)
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type DownloadTask struct {
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URL string
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FilePath string
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}
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func DownloadFileWithConcurrency(url, filepath string) error {
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resp, err := http.Head(url)
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if err != nil {
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return err
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}
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defer resp.Body.Close()
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fileSize, err := strconv.Atoi(resp.Header.Get("Content-Length"))
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if err != nil {
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return err
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}
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file, err := os.OpenFile(filepath, os.O_RDWR|os.O_CREATE, 0666)
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if err != nil {
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return err
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}
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defer file.Close()
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// 检查本地文件大小
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localFileSize, err := file.Seek(0, io.SeekEnd)
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if err != nil {
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return err
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}
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// 计算剩余未下载的文件大小
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remainingSize := fileSize - int(localFileSize)
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// 计算每个片段的大小
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chunkSize := remainingSize / MaxConcurrency
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// 创建等待组，用于等待所有goroutine完成
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var wg sync.WaitGroup
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wg.Add(MaxConcurrency)
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// 创建并发下载任务
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for i := 0; i < MaxConcurrency; i++ {
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start := localFileSize + int64(i*chunkSize)
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end := start + int64(chunkSize) - 1
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// 最后一个片段的结束位置可能超过文件大小，需要修正
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if i == MaxConcurrency-1 {
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end = int64(fileSize) - 1
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}
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go func(index int, start, end int64) {
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defer wg.Done()
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err := downloadChunk(url, filepath, start, end)
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if err != nil {
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biz.NewBizErr("文件下载失败")
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// 处理下载错误
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}
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}(i, start, end)
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}
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// 等待所有goroutine完成
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wg.Wait()
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return nil
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}
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func downloadChunk(url, filepath string, start, end int64) error {
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req, err := http.NewRequest("GET", url, nil)
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if err != nil {
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return err
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}
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// 设置Range头部
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req.Header.Set("Range", "bytes="+strconv.FormatInt(start, 10)+"-"+strconv.FormatInt(end, 10))
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resp, err := http.DefaultClient.Do(req)
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if err != nil {
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return err
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}
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defer resp.Body.Close()
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file, err := os.OpenFile(filepath, os.O_RDWR, 0666)
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if err != nil {
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return err
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}
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defer file.Close()
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_, err = file.Seek(start, io.SeekStart)
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if err != nil {
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return err
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}
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_, err = io.CopyN(file, resp.Body, end-start+1)
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if err != nil {
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return err
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}
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return nil
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}
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func SaveUploadedFile(file *multipart.FileHeader, dst string) error {
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src, err := file.Open()
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if err != nil {
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return err
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}
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defer src.Close()
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out, err := os.Create(dst)
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if err != nil {
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return err
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}
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defer out.Close()
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_, err = io.Copy(out, src)
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return err
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}
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