func()

in lambda/internal/tarfile/reader.go [113:144]

• 26 lines of code
• 8 McCabe index (conditional complexity)

func (r *S3FileReader) openTarComponent(componentPath string) (io.ReadCloser, error) {
	// We must clone at here because we need to make sure each tar reader must read from the beginning.
	// And the internal rcache should be shared.
	f := r.s3file.Clone()
	tarReader, header, err := findTarComponent(f, componentPath)
	if err != nil {
		return nil, err
	}
	if header == nil {
		return nil, os.ErrNotExist
	}
	if header.FileInfo().Mode()&os.ModeType == os.ModeSymlink { // FIXME: untested
		// We follow only one symlink; so no loops are possible.
		if _, err := f.Seek(0, io.SeekStart); err != nil {
			return nil, err
		}
		// The new path could easily point "outside" the archive, but we only compare it to existing tar headers without extracting the archive,
		// so we don't care.
		tarReader, header, err = findTarComponent(f, path.Join(path.Dir(componentPath), header.Linkname))
		if err != nil {
			return nil, err
		}
		if header == nil {
			return nil, os.ErrNotExist
		}
	}

	if !header.FileInfo().Mode().IsRegular() {
		return nil, errors.Errorf("Error reading tar archive component %s: not a regular file", header.Name)
	}
	return &tarReadCloser{Reader: tarReader}, nil
}