Example #1
0
// watcher for data change in etcd directory
func (p *service_pool) watcher() {
	client := p.client_pool.Get().(*etcd.Client)
	defer func() {
		p.client_pool.Put(client)
	}()

	for {
		ch := make(chan *etcd.Response, 10)
		go func() {
			for {
				if resp, ok := <-ch; ok {
					if resp.Node.Dir {
						continue
					}
					key, value := resp.Node.Key, resp.Node.Value
					if value == "" {
						log.Tracef("node delete: %v", key)
						p.remove_service(key)
					} else {
						log.Tracef("node add: %v %v", key, value)
						p.add_service(key, value)
					}
				} else {
					return
				}
			}
		}()

		_, err := client.Watch(DEFAULT_SERVICE_PATH, 0, true, ch, nil)
		if err != nil {
			log.Critical(err)
		}
		<-time.After(RETRY_DELAY)
	}
}
Example #2
0
// add a service
func (p *service_pool) add_service(key, value string) {
	p.Lock()
	defer p.Unlock()
	service_name := filepath.Dir(key)
	if p.services[service_name] == nil {
		p.services[service_name] = &service{}
		log.Tracef("new service type: %v", service_name)
	}
	service := p.services[service_name]

	if conn, err := grpc.Dial(value, grpc.WithTimeout(DEFAULT_DIAL_TIMEOUT)); err == nil {
		service.clients = append(service.clients, client{key, conn})
		log.Tracef("service added: %v -- %v", key, value)
	} else {
		log.Errorf("did not connect: %v -- %v err: %v", key, value, err)
	}
}
Example #3
0
// remove a service
func (p *service_pool) remove_service(key string) {
	p.Lock()
	defer p.Unlock()
	service_name := filepath.Dir(key)
	service := p.services[service_name]
	if service == nil {
		log.Tracef("no such service %v", service_name)
		return
	}

	for k := range service.clients {
		if service.clients[k].key == key { // deletion
			service.clients = append(service.clients[:k], service.clients[k+1:]...)
			log.Tracef("service removed %v", key)
			return
		}
	}
}
Example #4
0
// subscribe to an endpoint & receive server streams
func (s *server) Subscribe(p *Chat_Id, stream ChatService_SubscribeServer) error {
	// read endpoint
	ep := s.read_ep(p.Id)
	if ep == nil {
		log.Errorf("cannot find endpoint %v", p)
		return ERROR_NOT_EXISTS
	}

	// send history chat messages
	msgs := ep.Read()
	for k := range msgs {
		if err := stream.Send(&msgs[k]); err != nil {
			return nil
		}
	}

	// create subscriber
	e := make(chan error, 1)
	var once sync.Once
	f := NewSubscriber(func(msg *Chat_Message) {
		if err := stream.Send(msg); err != nil {
			once.Do(func() { // protect for channel blocking
				e <- err
			})
		}
	})

	// subscribe to the endpoint
	log.Tracef("subscribe to:%v", p.Id)
	ep.ps.Sub(f)
	defer func() {
		ep.ps.Leave(f)
		log.Tracef("leave from:%v", p.Id)
	}()

	// client send cancel to stop receiving, see service_test.go for example
	select {
	case <-stream.Context().Done():
	case <-e:
		log.Error(e)
	}
	return nil
}
Example #5
0
// add a service
func (p *service_pool) add_service(key, value string) {
	p.Lock()
	defer p.Unlock()
	service_name := filepath.Dir(key)
	// name check
	if p.enable_name_check && !p.service_names[service_name] {
		log.Warningf("service not in names: %v, ignored", service_name)
		return
	}

	if p.services[service_name] == nil {
		p.services[service_name] = &service{}
		log.Tracef("new service type: %v", service_name)
	}
	service := p.services[service_name]

	if conn, err := grpc.Dial(value, grpc.WithTimeout(DEFAULT_DIAL_TIMEOUT), grpc.WithInsecure()); err == nil {
		service.clients = append(service.clients, client{key, conn})
		log.Tracef("service added: %v -- %v", key, value)
	} else {
		log.Errorf("did not connect: %v -- %v err: %v", key, value, err)
	}
}