rpc: add subscription id to events (#6386)

Addresses  #3931

rpc/client/http/ws.go

@@ -52,7 +52,13 @@ type wsEvents struct {
 	ws *jsonrpcclient.WSClient
 
 	mtx           tmsync.RWMutex
-	subscriptions map[string]chan ctypes.ResultEvent // query -> chan
+	subscriptions map[string]*wsSubscription
+}
+
+type wsSubscription struct {
+	res   chan ctypes.ResultEvent
+	id    string
+	query string
 }
 
 var _ rpcclient.EventsClient = (*wsEvents)(nil)
@@ -70,7 +76,7 @@ func newWsEvents(remote string, wso WSOptions) (*wsEvents, error) {
 	}
 
 	w := &wsEvents{
-		subscriptions: make(map[string]chan ctypes.ResultEvent),
+		subscriptions: make(map[string]*wsSubscription),
 	}
 	w.BaseService = *service.NewBaseService(nil, "wsEvents", w)
 
@@ -136,10 +142,10 @@ func (w *wsEvents) Subscribe(ctx context.Context, subscriber, query string,
 
 	outc := make(chan ctypes.ResultEvent, outCap)
 	w.mtx.Lock()
+	defer w.mtx.Unlock()
 	// subscriber param is ignored because Tendermint will override it with
 	// remote IP anyway.
-	w.subscriptions[query] = outc
-	w.mtx.Unlock()
+	w.subscriptions[query] = &wsSubscription{res: outc, query: query}
 
 	return outc, nil
 }
@@ -158,9 +164,12 @@ func (w *wsEvents) Unsubscribe(ctx context.Context, subscriber, query string) er
 	}
 
 	w.mtx.Lock()
-	_, ok := w.subscriptions[query]
+	info, ok := w.subscriptions[query]
 	if ok {
-		delete(w.subscriptions, query)
+		if info.id != "" {
+			delete(w.subscriptions, info.id)
+		}
+		delete(w.subscriptions, info.query)
 	}
 	w.mtx.Unlock()
 
@@ -181,7 +190,7 @@ func (w *wsEvents) UnsubscribeAll(ctx context.Context, subscriber string) error
 	}
 
 	w.mtx.Lock()
-	w.subscriptions = make(map[string]chan ctypes.ResultEvent)
+	w.subscriptions = make(map[string]*wsSubscription)
 	w.mtx.Unlock()
 
 	return nil
@@ -196,7 +205,11 @@ func (w *wsEvents) redoSubscriptionsAfter(d time.Duration) {
 
 	w.mtx.Lock()
 	defer w.mtx.Unlock()
-	for q := range w.subscriptions {
+
+	for q, info := range w.subscriptions {
+		if q != "" && q == info.id {
+			continue
+		}
 		err := w.ws.Subscribe(ctx, q)
 		if err != nil {
 			w.Logger.Error("failed to resubscribe", "query", q, "err", err)
@@ -240,10 +253,17 @@ func (w *wsEvents) eventListener() {
 
 			w.mtx.RLock()
 			out, ok := w.subscriptions[result.Query]
+			if ok {
+				if _, idOk := w.subscriptions[result.SubscriptionID]; !idOk {
+					out.id = result.SubscriptionID
+					w.subscriptions[result.SubscriptionID] = out
+				}
+			}
+
 			w.mtx.RUnlock()
 			if ok {
 				select {
-				case out <- *result:
+				case out.res <- *result:
 				case <-w.Quit():
 					return
 				}

rpc/client/local/local.go

@@ -248,7 +248,13 @@ func (c *Local) eventsRoutine(
 	for {
 		select {
 		case msg := <-sub.Out():
-			result := ctypes.ResultEvent{Query: q.String(), Data: msg.Data(), Events: msg.Events()}
+			result := ctypes.ResultEvent{
+				SubscriptionID: msg.SubscriptionID(),
+				Query:          q.String(),
+				Data:           msg.Data(),
+				Events:         msg.Events(),
+			}
+
 			if cap(outc) == 0 {
 				outc <- result
 			} else {
@@ -293,11 +299,18 @@ func (c *Local) resubscribe(subscriber string, q tmpubsub.Query) types.Subscript
 }
 
 func (c *Local) Unsubscribe(ctx context.Context, subscriber, query string) error {
-	q, err := tmquery.New(query)
+	args := tmpubsub.UnsubscribeArgs{Subscriber: subscriber}
+	var err error
+	args.Query, err = tmquery.New(query)
 	if err != nil {
-		return fmt.Errorf("failed to parse query: %w", err)
+		// if this isn't a valid query it might be an ID, so
+		// we'll try that. It'll turn into an error when we
+		// try to unsubscribe. Eventually, perhaps, we'll want
+		// to change the interface to only allow
+		// unsubscription by ID, but that's a larger change.
+		args.ID = query
 	}
-	return c.EventBus.Unsubscribe(ctx, subscriber, q)
+	return c.EventBus.Unsubscribe(ctx, args)
 }
 
 func (c *Local) UnsubscribeAll(ctx context.Context, subscriber string) error {