Files
lingniu-vehicle-ingest/go/vehicle-gateway/internal/eventbus/nats_sink.go
2026-07-02 15:07:44 +08:00

118 lines
2.9 KiB
Go

package eventbus
import (
"context"
"errors"
"fmt"
"time"
"github.com/nats-io/nats.go"
"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
)
type NATSConfig struct {
URL string
Name string
RawSubjects map[envelope.Protocol]string
UnifiedSubject string
}
type NATSSink struct {
conn *nats.Conn
publisher natsPublisher
rawSubjects map[envelope.Protocol]string
unifiedSubject string
}
type NATSPublishOption = nats.PubOpt
type natsPublisher interface {
Publish(context.Context, string, []byte, ...NATSPublishOption) error
}
func NewNATSSink(cfg NATSConfig) (*NATSSink, error) {
if cfg.URL == "" {
return nil, errors.New("nats url is required")
}
name := cfg.Name
if name == "" {
name = "lingniu-vehicle-gateway"
}
conn, err := nats.Connect(cfg.URL, nats.Name(name), nats.Timeout(5*time.Second))
if err != nil {
return nil, err
}
js, err := conn.JetStream()
if err != nil {
conn.Close()
return nil, err
}
sink := newNATSSinkWithPublisher(natsJetStreamPublisher{js: js}, cfg)
sink.conn = conn
return sink, nil
}
func newNATSSinkWithPublisher(publisher natsPublisher, cfg NATSConfig) *NATSSink {
rawSubjects := map[envelope.Protocol]string{
envelope.ProtocolGB32960: "vehicle.raw.gb32960.v1",
envelope.ProtocolJT808: "vehicle.raw.jt808.v1",
envelope.ProtocolYutongMQTT: "vehicle.raw.yutong-mqtt.v1",
}
for protocol, subject := range cfg.RawSubjects {
if subject != "" {
rawSubjects[protocol] = subject
}
}
unifiedSubject := cfg.UnifiedSubject
if unifiedSubject == "" {
unifiedSubject = "vehicle.event.unified.v1"
}
return &NATSSink{
publisher: publisher,
rawSubjects: rawSubjects,
unifiedSubject: unifiedSubject,
}
}
func (s *NATSSink) PublishRaw(ctx context.Context, env envelope.FrameEnvelope) error {
subject, ok := s.rawSubjects[env.Protocol]
if !ok || subject == "" {
return fmt.Errorf("raw subject not configured for protocol %s", env.Protocol)
}
return s.publish(ctx, subject, env)
}
func (s *NATSSink) PublishUnified(ctx context.Context, env envelope.FrameEnvelope) error {
if s.unifiedSubject == "" {
return errors.New("unified subject is empty")
}
return s.publish(ctx, s.unifiedSubject, env)
}
func (s *NATSSink) Close() error {
if s == nil || s.conn == nil {
return nil
}
_ = s.conn.Drain()
s.conn.Close()
return nil
}
func (s *NATSSink) publish(ctx context.Context, subject string, env envelope.FrameEnvelope) error {
payload, err := env.MarshalJSONBytes()
if err != nil {
return err
}
return s.publisher.Publish(ctx, subject, payload, nats.MsgId(env.StableEventID()))
}
type natsJetStreamPublisher struct {
js nats.JetStreamContext
}
func (p natsJetStreamPublisher) Publish(ctx context.Context, subject string, data []byte, opts ...NATSPublishOption) error {
_, err := p.js.Publish(subject, data, append(opts, nats.Context(ctx))...)
return err
}