package types import ( "context" "fmt" tmpubsub "github.com/tendermint/tendermint/libs/pubsub" cmn "github.com/tendermint/tmlibs/common" "github.com/tendermint/tmlibs/log" ) const defaultCapacity = 0 type EventBusSubscriber interface { Subscribe(ctx context.Context, subscriber string, query tmpubsub.Query, out chan<- interface{}) error Unsubscribe(ctx context.Context, subscriber string, query tmpubsub.Query) error UnsubscribeAll(ctx context.Context, subscriber string) error } // EventBus is a common bus for all events going through the system. All calls // are proxied to underlying pubsub server. All events must be published using // EventBus to ensure correct data types. type EventBus struct { cmn.BaseService pubsub *tmpubsub.Server } // NewEventBus returns a new event bus. func NewEventBus() *EventBus { return NewEventBusWithBufferCapacity(defaultCapacity) } // NewEventBusWithBufferCapacity returns a new event bus with the given buffer capacity. func NewEventBusWithBufferCapacity(cap int) *EventBus { // capacity could be exposed later if needed pubsub := tmpubsub.NewServer(tmpubsub.BufferCapacity(cap)) b := &EventBus{pubsub: pubsub} b.BaseService = *cmn.NewBaseService(nil, "EventBus", b) return b } func (b *EventBus) SetLogger(l log.Logger) { b.BaseService.SetLogger(l) b.pubsub.SetLogger(l.With("module", "pubsub")) } func (b *EventBus) OnStart() error { return b.pubsub.OnStart() } func (b *EventBus) OnStop() { b.pubsub.OnStop() } func (b *EventBus) Subscribe(ctx context.Context, subscriber string, query tmpubsub.Query, out chan<- interface{}) error { return b.pubsub.Subscribe(ctx, subscriber, query, out) } func (b *EventBus) Unsubscribe(ctx context.Context, subscriber string, query tmpubsub.Query) error { return b.pubsub.Unsubscribe(ctx, subscriber, query) } func (b *EventBus) UnsubscribeAll(ctx context.Context, subscriber string) error { return b.pubsub.UnsubscribeAll(ctx, subscriber) } func (b *EventBus) Publish(eventType string, eventData TMEventData) error { // no explicit deadline for publishing events ctx := context.Background() b.pubsub.PublishWithTags(ctx, eventData, tmpubsub.NewTagMap(map[string]string{EventTypeKey: eventType})) return nil } //--- block, tx, and vote events func (b *EventBus) PublishEventNewBlock(event EventDataNewBlock) error { return b.Publish(EventNewBlock, event) } func (b *EventBus) PublishEventNewBlockHeader(event EventDataNewBlockHeader) error { return b.Publish(EventNewBlockHeader, event) } func (b *EventBus) PublishEventVote(event EventDataVote) error { return b.Publish(EventVote, event) } // PublishEventTx publishes tx event with tags from Result. Note it will add // predefined tags (EventTypeKey, TxHashKey). Existing tags with the same names // will be overwritten. func (b *EventBus) PublishEventTx(event EventDataTx) error { // no explicit deadline for publishing events ctx := context.Background() tags := make(map[string]string) // validate and fill tags from tx result for _, tag := range event.Result.Tags { // basic validation if len(tag.Key) == 0 { b.Logger.Info("Got tag with an empty key (skipping)", "tag", tag, "tx", event.Tx) continue } tags[string(tag.Key)] = string(tag.Value) } // add predefined tags logIfTagExists(EventTypeKey, tags, b.Logger) tags[EventTypeKey] = EventTx logIfTagExists(TxHashKey, tags, b.Logger) tags[TxHashKey] = fmt.Sprintf("%X", event.Tx.Hash()) logIfTagExists(TxHeightKey, tags, b.Logger) tags[TxHeightKey] = fmt.Sprintf("%d", event.Height) b.pubsub.PublishWithTags(ctx, event, tmpubsub.NewTagMap(tags)) return nil } func (b *EventBus) PublishEventProposalHeartbeat(event EventDataProposalHeartbeat) error { return b.Publish(EventProposalHeartbeat, event) } //--- EventDataRoundState events func (b *EventBus) PublishEventNewRoundStep(event EventDataRoundState) error { return b.Publish(EventNewRoundStep, event) } func (b *EventBus) PublishEventTimeoutPropose(event EventDataRoundState) error { return b.Publish(EventTimeoutPropose, event) } func (b *EventBus) PublishEventTimeoutWait(event EventDataRoundState) error { return b.Publish(EventTimeoutWait, event) } func (b *EventBus) PublishEventNewRound(event EventDataRoundState) error { return b.Publish(EventNewRound, event) } func (b *EventBus) PublishEventCompleteProposal(event EventDataRoundState) error { return b.Publish(EventCompleteProposal, event) } func (b *EventBus) PublishEventPolka(event EventDataRoundState) error { return b.Publish(EventPolka, event) } func (b *EventBus) PublishEventUnlock(event EventDataRoundState) error { return b.Publish(EventUnlock, event) } func (b *EventBus) PublishEventRelock(event EventDataRoundState) error { return b.Publish(EventRelock, event) } func (b *EventBus) PublishEventLock(event EventDataRoundState) error { return b.Publish(EventLock, event) } func logIfTagExists(tag string, tags map[string]string, logger log.Logger) { if value, ok := tags[tag]; ok { logger.Error("Found predefined tag (value will be overwritten)", "tag", tag, "value", value) } }