Function loadResponse

go/bundle/decoder.go:570–627

https://wicg.github.io/webpackage/draft-yasskin-dispatch-bundled-exchanges.html#load-response

(req requestEntryWithOffset, bs []byte)

// https://wicg.github.io/webpackage/draft-yasskin-dispatch-bundled-exchanges.html#load-response
func loadResponse(req requestEntryWithOffset, bs []byte) (Response, error) {
	r := bytes.NewBuffer(bs[req.Offset : req.Offset+req.Length])

	b, err := r.ReadByte()
	if err != nil {
		return Response{}, fmt.Errorf("bundle: Failed to read first byte of the encoded response: %v", err)
	}
	if b != 0x82 {
		return Response{}, fmt.Errorf("bundle: The first byte of the encoded response is %x, expected 0x82", b)
	}

	dec := cbor.NewDecoder(r)
	headerCborBytes, err := dec.DecodeByteString()
	if err != nil {
		return Response{}, fmt.Errorf("bundle: Failed to decode response header cbor bytestring: %v", err)
	}

	rhdr := bytes.NewBuffer(headerCborBytes)
	dechdr := cbor.NewDecoder(rhdr)
	headers, pseudos, err := decodeCborHeaders(dechdr)
	if err != nil {
		return Response{}, fmt.Errorf("bundle.response headerCbor: %v", err)
	}

	status, exists := pseudos[":status"]
	if !exists {
		return Response{}, fmt.Errorf("bundle.response headerCbor: pseudos don't have a key named \":status\"")
	}
	if len(pseudos) != 1 {
		return Response{}, fmt.Errorf("bundle.response headerCbor: len(pseudos) is %d, expected to be 1", len(pseudos))
	}

	if !reStatus.MatchString(status) {
		return Response{}, fmt.Errorf("bundle.response headerCbor: pseudos['status'] %q invalid", status)
	}

	body, err := dec.DecodeByteString()
	if err != nil {
		return Response{}, fmt.Errorf("bundle.response.body: %v", err)
	}

	if r.Len() != 0 {
		return Response{}, fmt.Errorf("bundle.response: invalid request stream end")
	}

	nstatus, err := strconv.Atoi(status)
	if err != nil {
		panic(err)
	}

	res := Response{
		Status: nstatus,
		Header: headers,
		Body:   body,
	}

	return res, nil
}