Function parseRewriteTemplateStruct

proto/rewrite.go:393–459

(t Type, f FieldNumber, j json.RawMessage, rules ...RewriterRules)

}

func parseRewriteTemplateStruct(t Type, f FieldNumber, j json.RawMessage, rules ...RewriterRules) (Rewriter, error) {
	template := map[string]json.RawMessage{}

	if err := json.Unmarshal(j, &template); err != nil {
		return nil, err
	}

	fieldsByName := map[string]Field{}

	for i := range t.NumField() {
		f := t.Field(i)
		fieldsByName[f.Name] = f
	}

	message := MessageRewriter{}
	rewriters := []Rewriter{}

	for k, v := range template {
		f, ok := fieldsByName[k]
		if !ok {
			return nil, fmt.Errorf("rewrite template contained an invalid field named %q", k)
		}

		var fields []json.RawMessage
		if f.Repeated {
			if err := json.Unmarshal(v, &fields); err != nil {
				return nil, err
			}
		} else {
			fields = []json.RawMessage{v}
		}

		var rule any
		for i := range rules {
			if r, ok := rules[i][f.Name]; ok {
				rule = r
				break
			}
		}

		rewriters = rewriters[:0]

		for _, v := range fields {
			rw, err := parseRewriteTemplate(f.Type, f.Number, v, rule)
			if err != nil {
				return nil, fmt.Errorf("%s: %w", k, err)
			}
			if rw != nil {
				rewriters = append(rewriters, rw)
			}
		}

		if cap(message) <= int(f.Number) {
			m := make(MessageRewriter, f.Number+1)
			copy(m, message)
			message = m
		}