97 lines
1.9 KiB
Go
97 lines
1.9 KiB
Go
package downloader
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import (
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"errors"
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"fmt"
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"io"
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"net/http"
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"os"
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"path"
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"strings"
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)
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type Downloader interface {
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Download(url string, filename string, pathname string) error
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GetRatio() float64
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}
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type DownloadTask struct {
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Filename string
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Path string
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Url string
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}
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func NewDownloadTask(filename string, path string, url string) *DownloadTask {
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return &DownloadTask{
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Filename: filename,
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Path: path,
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Url: url,
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}
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}
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func (t *DownloadTask) Valid() error {
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if t.Filename == "" {
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return errors.New("filename is empty")
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}
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if t.Url == "" {
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return errors.New("url is empty")
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}
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if t.Path == "" {
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return errors.New("path is empty")
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}
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if strings.Contains(t.Path, ",,") {
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return errors.New("path is invalid")
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}
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return nil
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}
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func isExists(pathname string) bool {
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_, err := os.Stat(pathname)
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return err == nil || !os.IsNotExist(err)
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}
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func isDir(pathname string) bool {
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info, err := os.Stat(pathname)
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if err != nil {
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return false
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}
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return info.IsDir()
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}
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func (t *DownloadTask) Download() error {
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if err := t.Valid(); err != nil {
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return err
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}
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if isExists(t.Path) {
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if !isDir(t.Path) {
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return errors.New("path is not a directory")
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}
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if isExists(path.Join(t.Path, t.Filename)) {
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return errors.New("file already exists")
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}
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} else {
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if err := os.Mkdir(t.Path, 0755); err != nil {
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return err
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}
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}
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resp, err := http.Get(t.Url)
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if err != nil {
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return fmt.Errorf("failed to download %s: %w", t.Url, err)
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}
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defer resp.Body.Close()
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contentLength := resp.ContentLength
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if contentLength < 0 {
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return errors.New("failed to get content length")
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}
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file, err := os.Create(path.Join(t.Path, t.Filename))
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if err != nil {
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return fmt.Errorf("failed to create file %s: %w", t.Filename, err)
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}
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defer file.Close()
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_, err = io.Copy(file, resp.Body)
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if err != nil {
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return fmt.Errorf("failed to write file %s: %w", t.Filename, err)
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}
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return nil
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}
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