log.Fatalf("writing %s%s: %v", name, extra, err)
		}
	}()

	zw := zip.NewWriter(out)
	zw.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) {
		return flate.NewWriter(out, flate.BestCompression)
	})
	for _, f = range a.Files {
		h := check(zip.FileInfoHeader(f.Info()))
		h.Name = f.Name
		h.Method = zip.Deflate
		w := check(zw.CreateHeader(h))
		r := check(os.Open(f.Src))
		check(io.Copy(w, r))

	b := marshal(p)
	p.encodeMu.Unlock()
	return b
}

// Write writes the profile as a gzip-compressed marshaled protobuf.
func (p *Profile) Write(w io.Writer) error {
	zw := gzip.NewWriter(w)
	defer zw.Close()
	_, err := zw.Write(serialize(p))
	return err
}

// WriteUncompressed writes the profile as a marshaled protobuf.
func (p *Profile) WriteUncompressed(w io.Writer) error {