func()

in wim/wim.go [780:844]
55 lines of code
11 McCabe index (conditional complexity)

func (img *Image) readNextStream(r io.Reader) (*Stream, int64, error) {
	var length int64
	err := binary.Read(r, binary.LittleEndian, &length)
	if err != nil {
		if err == io.EOF {
			err = io.ErrUnexpectedEOF
		}
		return nil, 0, &ParseError{Oper: "stream length check", Err: err}
	}

	left := length
	if left < streamentrySize {
		return nil, 0, &ParseError{Oper: "stream entry", Err: errors.New("size too short")}
	}

	var sentry streamentry
	err = binary.Read(r, binary.LittleEndian, &sentry)
	if err != nil {
		return nil, 0, &ParseError{Oper: "stream entry", Err: err}
	}

	left -= streamentrySize

	if left < int64(sentry.NameLength) {
		return nil, 0, &ParseError{Oper: "stream entry", Err: errors.New("size too short for name")}
	}

	names := make([]uint16, sentry.NameLength/2)
	err = binary.Read(r, binary.LittleEndian, names)
	if err != nil {
		return nil, 0, &ParseError{Oper: "file name", Err: err}
	}

	left -= int64(sentry.NameLength)
	name := string(utf16.Decode(names))

	var offset resourceDescriptor
	if sentry.Hash != (SHA1Hash{}) {
		var ok bool
		offset, ok = img.wim.fileData[sentry.Hash]
		if !ok {
			return nil, 0, &ParseError{Oper: "stream entry", Path: name, Err: fmt.Errorf("could not find file data matching hash %v", sentry.Hash)}
		}
	}

	s := &Stream{
		StreamHeader: StreamHeader{
			Hash: sentry.Hash,
			Size: offset.OriginalSize,
			Name: name,
		},
		wim:    img.wim,
		offset: offset,
	}

	_, err = io.CopyN(ioutil.Discard, r, left)
	if err != nil {
		if err == io.EOF {
			err = io.ErrUnexpectedEOF
		}
		return nil, 0, err
	}

	return s, length, nil
}