feat: add getActiveSubscriptions method (#1249)

Author: weboko

packages/core/src/lib/relay/index.ts

@@ -6,17 +6,17 @@ import {
 } from "@chainsafe/libp2p-gossipsub";
 import type { PeerIdStr, TopicStr } from "@chainsafe/libp2p-gossipsub/types";
 import { SignaturePolicy } from "@chainsafe/libp2p-gossipsub/types";
-import { CustomEvent } from "@libp2p/interfaces/events";
 import type {
+  ActiveSubscriptions,
   Callback,
+  IDecodedMessage,
   IDecoder,
   IEncoder,
   IMessage,
   IRelay,
   ProtocolCreateOptions,
   SendResult,
 } from "@waku/interfaces";
-import { IDecodedMessage } from "@waku/interfaces";
 import debug from "debug";
 
 import { DefaultPubSubTopic } from "../constants.js";
@@ -36,10 +36,6 @@ export type Observer<T extends IDecodedMessage> = {
 export type RelayCreateOptions = ProtocolCreateOptions & GossipsubOpts;
 export type ContentTopic = string;
 
-type BasicEventPayload = {
-  contentTopic: string;
-};
-
 /**
  * Implements the [Waku v2 Relay protocol](https://rfc.vac.dev/spec/11/).
  * Must be passed as a `pubsub` module to a `Libp2p` instance.
@@ -120,30 +116,20 @@ class Relay extends GossipSub implements IRelay {
 
     pushOrInitMapSet(this.observers, contentTopic, observer);
 
-    this.dispatchEvent(
-      new CustomEvent<BasicEventPayload>("observer:added", {
-        detail: {
-          contentTopic,
-        },
-      })
-    );
-
     return () => {
       const observers = this.observers.get(contentTopic);
       if (observers) {
         observers.delete(observer);
-
-        this.dispatchEvent(
-          new CustomEvent<BasicEventPayload>("observer:removed", {
-            detail: {
-              contentTopic,
-            },
-          })
-        );
       }
     };
   }
 
+  public getActiveSubscriptions(): ActiveSubscriptions {
+    const map = new Map();
+    map.set(this.pubSubTopic, this.observers.keys());
+    return map;
+  }
+
   private async processIncomingMessage<T extends IDecodedMessage>(
     pubSubTopic: string,
     bytes: Uint8Array

packages/interfaces/src/relay.ts

@@ -1,23 +1,21 @@
-import type { GossipSub, GossipsubEvents } from "@chainsafe/libp2p-gossipsub";
-import type { EventEmitter } from "@libp2p/interfaces/events";
+import type { GossipSub } from "@chainsafe/libp2p-gossipsub";
 
 import type { IDecodedMessage, IDecoder } from "./message.js";
 import type { Callback } from "./protocols.js";
 import type { ISender } from "./sender.js";
 
-export interface RelayEvents {
-  "observer:added": CustomEvent;
-  "observer:removed": CustomEvent;
-}
+type PubSubTopic = string;
+type ContentTopic = string;
 
-type IRelayEmitter = EventEmitter<RelayEvents & GossipsubEvents>;
+export type ActiveSubscriptions = Map<PubSubTopic, ContentTopic[]>;
 
 interface IRelayAPI {
   addObserver: <T extends IDecodedMessage>(
     decoder: IDecoder<T>,
     callback: Callback<T>
   ) => () => void;
   getMeshPeers: () => string[];
+  getActiveSubscriptions: () => ActiveSubscriptions | undefined;
 }
 
-export type IRelay = ISender & GossipSub & IRelayAPI & IRelayEmitter;
+export type IRelay = IRelayAPI & GossipSub & ISender;