package webseed import ( "fmt" "net/http" "net/url" "path" "strings" "github.com/anacrolix/torrent/metainfo" ) func trailingPath(infoName string, pathComps []string) string { return path.Join( func() (ret []string) { for _, comp := range append([]string{infoName}, pathComps...) { ret = append(ret, url.QueryEscape(comp)) } return }()..., ) } // Creates a request per BEP 19. func NewRequest(url_ string, fileIndex int, info *metainfo.Info, offset, length int64) (*http.Request, error) { fileInfo := info.UpvertedFiles()[fileIndex] if strings.HasSuffix(url_, "/") { // BEP specifies that we append the file path. We need to escape each component of the path // for things like spaces and '#'. url_ += trailingPath(info.Name, fileInfo.Path) } req, err := http.NewRequest(http.MethodGet, url_, nil) if err != nil { return nil, err } if offset != 0 || length != fileInfo.Length { req.Header.Set("Range", fmt.Sprintf("bytes=%d-%d", offset, offset+length-1)) } return req, nil }