Function readUnpackInfo

types.go:391–484

nolint:cyclop,funlen,gocognit

(r util.Reader)

//nolint:cyclop,funlen,gocognit
func readUnpackInfo(r util.Reader) (*unpackInfo, error) {
	u := new(unpackInfo)

	if id, err := r.ReadByte(); err != nil || id != idFolder {
		if err != nil {
			return nil, fmt.Errorf("readUnpackInfo: ReadByte error: %w", err)
		}

		return nil, errUnexpectedID
	}

	folders, err := readUint64Bounded(r, true)
	if err != nil {
		return nil, err
	}

	external, err := r.ReadByte()
	if err != nil {
		return nil, fmt.Errorf("readUnpackInfo: ReadByte error: %w", err)
	}

	if external > 0 {
		/*
			_, err := readUint64(r)
			if err != nil {
				return nil, err
			}
		*/
		// TODO Apparently we seek to this read offset and read the
		// folder information from there. Not clear if the offset is
		// absolute for the whole file, or relative to some known
		// position in the file. Cowardly waiting for an example
		return nil, errors.New("sevenzip: TODO readUnpackInfo external") //nolint:err113
	}

	u.folder = make([]*folder, 0, min(folders, 1024))

	for range folders {
		folder, err := readFolder(r)
		if err != nil {
			return nil, err
		}

		u.folder = append(u.folder, folder)
	}

	if id, err := r.ReadByte(); err != nil || id != idCodersUnpackSize {
		if err != nil {
			return nil, fmt.Errorf("readUnpackInfo: ReadByte error: %w", err)
		}

		return nil, errUnexpectedID
	}

	for _, f := range u.folder {
		total := uint64(0)
		for _, c := range f.coder {
			total += c.out