feat!: add and implement IReceiver

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

@@ -2,6 +2,7 @@ import type { Libp2p } from "@libp2p/interface-libp2p";
 import type { Peer } from "@libp2p/interface-peer-store";
 import type { IncomingStreamData } from "@libp2p/interface-registrar";
 import type {
+  ActiveSubscriptions,
   Callback,
   IDecodedMessage,
   IDecoder,
@@ -58,19 +59,20 @@ class Filter extends BaseProtocol implements IFilter {
   }
 
   /**
-   * @param decoders Array of Decoders to use to decode messages, it also specifies the content topics.
+   * @param decoders Decoder or array of Decoders to use to decode messages, it also specifies the content topics.
    * @param callback A function that will be called on each message returned by the filter.
    * @param opts The FilterSubscriptionOpts used to narrow which messages are returned, and which peer to connect to.
    * @returns Unsubscribe function that can be used to end the subscription.
    */
   async subscribe<T extends IDecodedMessage>(
-    decoders: IDecoder<T>[],
+    decoders: IDecoder<T> | IDecoder<T>[],
     callback: Callback<T>,
     opts?: ProtocolOptions
   ): Promise<UnsubscribeFunction> {
+    const decodersArray = Array.isArray(decoders) ? decoders : [decoders];
     const { pubSubTopic = DefaultPubSubTopic } = this.options;
 
-    const contentTopics = Array.from(groupByContentTopic(decoders).keys());
+    const contentTopics = Array.from(groupByContentTopic(decodersArray).keys());
 
     const contentFilters = contentTopics.map((contentTopic) => ({
       contentTopic,
@@ -109,7 +111,11 @@ class Filter extends BaseProtocol implements IFilter {
       throw e;
     }
 
-    const subscription: Subscription<T> = { callback, decoders, pubSubTopic };
+    const subscription: Subscription<T> = {
+      callback,
+      decoders: decodersArray,
+      pubSubTopic,
+    };
     this.subscriptions.set(requestId, subscription);
 
     return async () => {
@@ -118,6 +124,22 @@ class Filter extends BaseProtocol implements IFilter {
     };
   }
 
+  public getActiveSubscriptions(): ActiveSubscriptions {
+    const map: ActiveSubscriptions = new Map();
+    const subscriptions = this.subscriptions as Map<
+      RequestID,
+      Subscription<IDecodedMessage>
+    >;
+
+    for (const item of subscriptions.values()) {
+      const values = map.get(item.pubSubTopic) || [];
+      const nextValues = item.decoders.map((decoder) => decoder.contentTopic);
+      map.set(item.pubSubTopic, [...values, ...nextValues]);
+    }
+
+    return map;
+  }
+
   private onRequest(streamData: IncomingStreamData): void {
     log("Receiving message push");
     try {

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

@@ -20,8 +20,8 @@ import type {
 import debug from "debug";
 
 import { DefaultPubSubTopic } from "../constants.js";
+import { groupByContentTopic } from "../group_by.js";
 import { TopicOnlyDecoder } from "../message/topic_only_message.js";
-import { pushOrInitMapSet } from "../push_or_init_map.js";
 
 import * as constants from "./constants.js";
 import { messageValidator } from "./message_validator.js";
@@ -42,10 +42,12 @@ export type ContentTopic = string;
  *
  * @implements {require('libp2p-interfaces/src/pubsub')}
  */
-class Relay extends GossipSub implements IRelay {
+class Relay implements IRelay {
   private readonly pubSubTopic: string;
-  defaultDecoder: IDecoder<IDecodedMessage>;
+  private defaultDecoder: IDecoder<IDecodedMessage>;
+
   public static multicodec: string = constants.RelayCodecs[0];
+  public readonly gossipSub: GossipSub;
 
   /**
    * observers called when receiving new message.
@@ -63,8 +65,8 @@ class Relay extends GossipSub implements IRelay {
       fallbackToFloodsub: false,
     });
 
-    super(components, options);
-    this.multicodecs = constants.RelayCodecs;
+    this.gossipSub = new GossipSub(components, options);
+    this.gossipSub.multicodecs = constants.RelayCodecs;
 
     this.pubSubTopic = options?.pubSubTopic ?? DefaultPubSubTopic;
 
@@ -82,8 +84,8 @@ class Relay extends GossipSub implements IRelay {
    * @returns {void}
    */
   public async start(): Promise<void> {
-    await super.start();
-    this.subscribe(this.pubSubTopic);
+    await this.gossipSub.start();
+    this.gossipSubSubscribe(this.pubSubTopic);
   }
 
   /**
@@ -96,30 +98,46 @@ class Relay extends GossipSub implements IRelay {
       return { recipients: [] };
     }
 
-    return this.publish(this.pubSubTopic, msg);
+    return this.gossipSub.publish(this.pubSubTopic, msg);
   }
 
   /**
    * Add an observer and associated Decoder to process incoming messages on a given content topic.
    *
    * @returns Function to delete the observer
    */
-  addObserver<T extends IDecodedMessage>(
-    decoder: IDecoder<T>,
+  public subscribe<T extends IDecodedMessage>(
+    decoders: IDecoder<T> | IDecoder<T>[],
     callback: Callback<T>
   ): () => void {
-    const observer = {
-      decoder,
-      callback,
-    };
-    const contentTopic = decoder.contentTopic;
+    const contentTopicToObservers = Array.isArray(decoders)
+      ? toObservers(decoders, callback)
+      : toObservers([decoders], callback);
 
-    pushOrInitMapSet(this.observers, contentTopic, observer);
+    for (const contentTopic of contentTopicToObservers.keys()) {
+      const currObservers = this.observers.get(contentTopic) || new Set();
+      const newObservers =
+        contentTopicToObservers.get(contentTopic) || new Set();
+
+      this.observers.set(contentTopic, union(currObservers, newObservers));
+    }
 
     return () => {
-      const observers = this.observers.get(contentTopic);
-      if (observers) {
-        observers.delete(observer);
+      for (const contentTopic of contentTopicToObservers.keys()) {
+        const currentObservers = this.observers.get(contentTopic) || new Set();
+        const observersToRemove =
+          contentTopicToObservers.get(contentTopic) || new Set();
+
+        const nextObservers = leftMinusJoin(
+          currentObservers,
+          observersToRemove
+        );
+
+        if (nextObservers.size) {
+          this.observers.set(contentTopic, nextObservers);
+        } else {
+          this.observers.delete(contentTopic);
+        }
       }
     };
   }
@@ -130,6 +148,10 @@ class Relay extends GossipSub implements IRelay {
     return map;
   }
 
+  public getMeshPeers(topic?: TopicStr): PeerIdStr[] {
+    return this.gossipSub.getMeshPeers(topic ?? this.pubSubTopic);
+  }
+
   private async processIncomingMessage<T extends IDecodedMessage>(
     pubSubTopic: string,
     bytes: Uint8Array
@@ -168,8 +190,8 @@ class Relay extends GossipSub implements IRelay {
    *
    * @override
    */
-  subscribe(pubSubTopic: string): void {
-    this.addEventListener(
+  private gossipSubSubscribe(pubSubTopic: string): void {
+    this.gossipSub.addEventListener(
       "gossipsub:message",
       async (event: CustomEvent<GossipsubMessage>) => {
         if (event.detail.msg.topic !== pubSubTopic) return;
@@ -182,17 +204,8 @@ class Relay extends GossipSub implements IRelay {
       }
     );
 
-    this.topicValidators.set(pubSubTopic, messageValidator);
-    super.subscribe(pubSubTopic);
-  }
-
-  unsubscribe(pubSubTopic: TopicStr): void {
-    super.unsubscribe(pubSubTopic);
-    this.topicValidators.delete(pubSubTopic);
-  }
-
-  getMeshPeers(topic?: TopicStr): PeerIdStr[] {
-    return super.getMeshPeers(topic ?? this.pubSubTopic);
+    this.gossipSub.topicValidators.set(pubSubTopic, messageValidator);
+    this.gossipSub.subscribe(pubSubTopic);
   }
 }
 
@@ -203,3 +216,46 @@ export function wakuRelay(
 ): (components: GossipSubComponents) => IRelay {
   return (components: GossipSubComponents) => new Relay(components, init);
 }
+
+function toObservers<T extends IDecodedMessage>(
+  decoders: IDecoder<T>[],
+  callback: Callback<T>
+): Map<ContentTopic, Set<Observer<T>>> {
+  const contentTopicToDecoders = Array.from(
+    groupByContentTopic(decoders).entries()
+  );
+
+  const contentTopicToObserversEntries = contentTopicToDecoders.map(
+    ([contentTopic, decoders]) =>
+      [
+        contentTopic,
+        new Set(
+          decoders.map(
+            (decoder) =>
+              ({
+                decoder,
+                callback,
+              } as Observer<T>)
+          )
+        ),
+      ] as [ContentTopic, Set<Observer<T>>]
+  );
+
+  return new Map(contentTopicToObserversEntries);
+}
+
+function union(left: Set<unknown>, right: Set<unknown>): Set<unknown> {
+  for (const val of right.values()) {
+    left.add(val);
+  }
+  return left;
+}
+
+function leftMinusJoin(left: Set<unknown>, right: Set<unknown>): Set<unknown> {
+  for (const val of right.values()) {
+    if (left.has(val)) {
+      left.delete(val);
+    }
+  }
+  return left;
+}

packages/core/src/lib/wait_for_remote_peer.ts

@@ -105,7 +105,7 @@ async function waitForGossipSubPeerInMesh(waku: IRelay): Promise<void> {
   let peers = waku.getMeshPeers();
 
   while (peers.length == 0) {
-    await pEvent(waku, "gossipsub:heartbeat");
+    await pEvent(waku.gossipSub, "gossipsub:heartbeat");
     peers = waku.getMeshPeers();
   }
 }

packages/core/src/lib/waku.ts

@@ -1,7 +1,6 @@
 import type { Stream } from "@libp2p/interface-connection";
 import type { Libp2p } from "@libp2p/interface-libp2p";
 import type { PeerId } from "@libp2p/interface-peer-id";
-import type { PubSub } from "@libp2p/interface-pubsub";
 import type { Multiaddr } from "@multiformats/multiaddr";
 import type {
   IFilter,
@@ -71,8 +70,10 @@ export class WakuNode implements Waku {
       this.lightPush = lightPush(libp2p);
     }
 
-    if (isRelay(libp2p.pubsub)) {
-      this.relay = libp2p.pubsub;
+    // since wakuRelay function will make it IRelay and not PubSub
+    const maybeRelay = libp2p.pubsub as unknown as IRelay;
+    if (isRelay(maybeRelay)) {
+      this.relay = maybeRelay;
     }
 
     const pingKeepAlive =
@@ -120,7 +121,9 @@ export class WakuNode implements Waku {
     const codecs: string[] = [];
     if (_protocols.includes(Protocols.Relay)) {
       if (this.relay) {
-        this.relay.multicodecs.forEach((codec) => codecs.push(codec));
+        this.relay.gossipSub.multicodecs.forEach((codec: string) =>
+          codecs.push(codec)
+        );
       } else {
         log(
           "Relay codec not included in dial codec: protocol not mounted locally"
@@ -189,10 +192,10 @@ export class WakuNode implements Waku {
   }
 }
 
-function isRelay(pubsub: PubSub): pubsub is IRelay {
-  if (pubsub) {
+function isRelay(maybeRelay: IRelay): boolean {
+  if (maybeRelay) {
     try {
-      return pubsub.multicodecs.includes(
+      return maybeRelay.gossipSub.multicodecs.includes(
         relayConstants.RelayCodecs[relayConstants.RelayCodecs.length - 1]
       );
       // Exception is expected if `libp2p` was not instantiated with pubsub

packages/interfaces/src/filter.ts

@@ -1,14 +1,4 @@
-import type { IDecodedMessage, IDecoder } from "./message.js";
-import type {
-  Callback,
-  PointToPointProtocol,
-  ProtocolOptions,
-} from "./protocols.js";
+import type { PointToPointProtocol } from "./protocols.js";
+import type { IReceiver } from "./receiver.js";
 
-export interface IFilter extends PointToPointProtocol {
-  subscribe: <T extends IDecodedMessage>(
-    decoders: IDecoder<T>[],
-    callback: Callback<T>,
-    opts?: ProtocolOptions
-  ) => Promise<() => Promise<void>>;
-}
+export type IFilter = IReceiver & PointToPointProtocol;

packages/interfaces/src/index.ts

@@ -9,3 +9,4 @@ export * from "./store.js";
 export * from "./waku.js";
 export * from "./connection_manager.js";
 export * from "./sender.js";
+export * from "./receiver.js";

packages/interfaces/src/receiver.ts

@@ -0,0 +1,17 @@
+import type { IDecodedMessage, IDecoder } from "./message.js";
+import type { Callback, ProtocolOptions } from "./protocols.js";
+
+type Unsubscribe = () => void | Promise<void>;
+type PubSubTopic = string;
+type ContentTopic = string;
+
+export type ActiveSubscriptions = Map<PubSubTopic, ContentTopic[]>;
+
+export interface IReceiver {
+  subscribe: <T extends IDecodedMessage>(
+    decoders: IDecoder<T> | IDecoder<T>[],
+    callback: Callback<T>,
+    opts?: ProtocolOptions
+  ) => Unsubscribe | Promise<Unsubscribe>;
+  getActiveSubscriptions: () => ActiveSubscriptions;
+}

packages/interfaces/src/relay.ts

@@ -1,21 +1,13 @@
 import type { GossipSub } from "@chainsafe/libp2p-gossipsub";
+import type { PeerIdStr, TopicStr } from "@chainsafe/libp2p-gossipsub/types";
 
-import type { IDecodedMessage, IDecoder } from "./message.js";
-import type { Callback } from "./protocols.js";
+import { IReceiver } from "./receiver.js";
 import type { ISender } from "./sender.js";
 
-type PubSubTopic = string;
-type ContentTopic = string;
-
-export type ActiveSubscriptions = Map<PubSubTopic, ContentTopic[]>;
-
 interface IRelayAPI {
-  addObserver: <T extends IDecodedMessage>(
-    decoder: IDecoder<T>,
-    callback: Callback<T>
-  ) => () => void;
-  getMeshPeers: () => string[];
-  getActiveSubscriptions: () => ActiveSubscriptions | undefined;
+  readonly gossipSub: GossipSub;
+  start: () => Promise<void>;
+  getMeshPeers: (topic?: TopicStr) => PeerIdStr[];
 }
 
-export type IRelay = IRelayAPI & GossipSub & ISender;
+export type IRelay = IRelayAPI & ISender & IReceiver;

packages/tests/tests/filter.node.spec.ts

@@ -78,7 +78,7 @@ describe("Waku Filter", () => {
       messageCount++;
       expect(msg.contentTopic).to.eq(TestContentTopic);
     };
-    await waku.filter.subscribe([TestDecoder], callback);
+    await waku.filter.subscribe(TestDecoder, callback);
 
     await delay(200);
     await waku.lightPush.send(TestEncoder, {