cleanup, forwarding now handled by subscriptionHandler

subscriptionHandler.ts

@@ -0,0 +1,62 @@
+import { WS } from "./index";
+
+export interface Subscriber {
+  send: (message: string) => void;
+}
+
+export class SubscriptionMap {
+  channelsPerSubscriber = new Map<Subscriber, Set<string>>();
+  subscribersPerChannel = new Map<string, Set<Subscriber>>();
+
+  // prepare
+  private prepareChannelSet(subscriber: Subscriber): void {
+    if (this.channelsPerSubscriber.has(subscriber)) return;
+    this.channelsPerSubscriber.set(subscriber, new Set());
+  }
+
+  private prepareSubscriberSet(channel: string): void {
+    if (this.subscribersPerChannel.has(channel)) return;
+    this.subscribersPerChannel.set(channel, new Set());
+  }
+
+  // utility
+  getChannelList(subscriber: Subscriber): Set<string> | undefined {
+    return this.channelsPerSubscriber.get(subscriber);
+  }
+
+  getClientList(channel: string): Set<Subscriber> | undefined {
+    return this.subscribersPerChannel.get(channel);
+  }
+
+  // modifications
+  set(subscriber: Subscriber, channel: string): void {
+    this.prepareChannelSet(subscriber);
+    this.prepareSubscriberSet(channel);
+
+    this.getChannelList(subscriber)?.add(channel);
+    this.getClientList(channel)?.add(subscriber);
+  }
+
+  delete(subscriber: Subscriber, channel: string): void {
+    const channelList = this.getChannelList(subscriber);
+    const clientList = this.getClientList(channel);
+
+    channelList?.delete(channel);
+    if (channelList?.size == 0) {
+      this.channelsPerSubscriber.delete(subscriber);
+    }
+
+    clientList?.delete(subscriber);
+    if (clientList?.size == 0) {
+      this.subscribersPerChannel.delete(channel);
+    }
+  }
+
+  // messages
+  forwardMessage(channels: string[], messageString: string): void {
+    channels.forEach((channel) => {
+      const subscribers = this.getClientList(channel);
+      subscribers?.forEach((subscriber) => subscriber.send(messageString));
+    });
+  }
+}