Fix some bugs with message delivery

src/Pool.ts

@@ -0,0 +1,31 @@
+import {Socket} from "./util/Socket"
+
+export class Pool {
+  data: Map<string, Socket>
+  constructor() {
+    this.data = new Map()
+  }
+  has(url) {
+    return this.data.has(url)
+  }
+  get(url) {
+    if (!this.data.has(url)) {
+      this.data.set(url, new Socket(url))
+    }
+
+    return this.data.get(url)
+  }
+  remove(url) {
+    const socket = this.data.get(url)
+
+    if (socket) {
+      socket.disconnect()
+      this.data.delete(url)
+    }
+  }
+  clear() {
+    for (const url of this.data.keys()) {
+      this.remove(url)
+    }
+  }
+}