Angular 6 socket.io如何创建可观察的服务？

Question

我在socket.io上遇到了Angular服务问题。服务推送数据仅以其他方式查看。但是我的问题是，如何创建可观察的。例如，应该是一个，还是每个订阅新的Observable？

第一个选项

export class MessageService {

socket: SocketIOClient.Socket;
observable: Observable<any>;
subject: Subject<any>;

constructor() {
    this.subject = new Subject();
    this.observable = new Observable<any>(this.subscribe.bind(this));
}

init() {
    if (!this.socket) {
        this.socket = io('http://localhost:3000');
        this.socket.on('message', (res) => {
            this.subject.next(res);
        });
    }
}

getMessage(): Observable<any> {
    this.init();
    return this.observable;
}

private subscribe(subscriber: Subscriber<any>) {
    this.subject.subscribe(subscriber);
}
}

第二个选项

export class MessageService {

socket: SocketIOClient.Socket;
observable: Observable<any>;
subject: Subject<any>;

constructor() {
    this.subject = new Subject();
}

init() {
    if (!this.socket) {
        this.socket = io('http://localhost:3000');
        this.socket.on('message', (res) => {
            this.subject.next(res);
        });
    }
}

getMessage(): Observable<any> {
    this.init();
    return new Observable<any>(subscriber => {
        this.subject.subscribe(subscriber);
    });
}
}

哪个选项是最佳，更快，更安全的方式。 还是我误解了有关可观察物的某些内容？