Method toFastJSON

query/outputnode.go:1180–1225

(ctx context.Context, l *Latency, field gqlSchema.Field)

}

func (sg *SubGraph) toFastJSON(ctx context.Context, l *Latency, field gqlSchema.Field) ([]byte,
	error) {
	encodingStart := time.Now()
	defer func() {
		l.Json = time.Since(encodingStart)
	}()

	enc := newEncoder()
	defer func() {
		// Put encoder's arena back to arena pool.
		arenaPool.Put(enc.arena)
		enc.alloc.Release()
	}()

	var err error
	n := enc.newNode(enc.idForAttr("_root_"))
	for _, sg := range sg.Children {
		err = processNodeUids(n, enc, sg)
		if err != nil {
			return nil, err
		}
	}
	enc.fixOrder(n)

	// According to GraphQL spec response should only contain data, errors and extensions as top
	// level keys. Hence we send server_latency under extensions key.
	// https://facebook.github.io/graphql/#sec-Response-Format

	// if there is a GraphQL field that means we need to encode the response in GraphQL form,
	// otherwise encode it in DQL form.
	if field != nil {
		// if there were any GraphQL errors, we need to propagate them back to GraphQL layer along
		// with the data. So, don't return here if we get an error.
		err = sg.toGraphqlJSON(newGraphQLEncoder(ctx, enc), n, field)
	} else if err = sg.toDqlJSON(enc, n); err != nil {
		return nil, err
	}

	// Return error if encoded buffer size exceeds than a threshold size.
	if uint64(enc.buf.Len()) > maxEncodedSize {
		return nil, fmt.Errorf("while writing to buffer. Encoded response size: %d"+
			" is bigger than threshold: %d", enc.buf.Len(), maxEncodedSize)
	}

	return enc.buf.Bytes(), err
}

func (sg *SubGraph) toDqlJSON(enc *encoder, n fastJsonNode) error {
	if enc.children(n) == nil {