func()

in swim/join_sender.go [282:360]

• 65 lines of code
• 6 McCabe index (conditional complexity)

func (j *joinSender) JoinCluster() ([]string, error) {
	var nodesJoined []string
	var numGroups = 0
	var numJoined = 0
	var numFailed = 0
	var startTime = time.Now()

	if util.SingleNodeCluster(j.node.address, j.bootstrapHostsMap) {
		j.logger.Info("got single node cluster to join")
		return nodesJoined, nil
	}

	for {
		if j.node.Destroyed() {
			j.node.EmitEvent(JoinFailedEvent{
				Reason: Destroyed,
				Error:  nil,
			})
			return nil, errors.New("node destroyed while attempting to join cluster")
		}
		// join group of nodes
		successes, failures := j.JoinGroup(nodesJoined)

		nodesJoined = append(nodesJoined, successes...)
		numJoined += len(successes)
		numFailed += len(failures)
		numGroups++

		if numJoined >= j.size {
			j.logger.WithFields(log.Fields{
				"joinSize":  j.size,
				"joinTime":  time.Now().Sub(startTime),
				"numJoined": numJoined,
				"numFailed": numFailed,
				"numGroups": numGroups,
			}).Debug("join complete")

			break
		}

		joinDuration := time.Now().Sub(startTime)

		if joinDuration > j.maxJoinDuration {
			j.logger.WithFields(log.Fields{
				"joinDuration":    joinDuration,
				"maxJoinDuration": j.maxJoinDuration,
				"numJoined":       numJoined,
				"numFailed":       numFailed,
				"startTime":       startTime,
			}).Warn("max join duration exceeded")

			err := fmt.Errorf("join duration of %v exceeded max %v",
				joinDuration, j.maxJoinDuration)

			j.node.EmitEvent(JoinFailedEvent{
				Reason: Error,
				Error:  err,
			})
			return nodesJoined, err
		}

		j.logger.WithFields(log.Fields{
			"joinSize":  j.size,
			"numJoined": numJoined,
			"numFailed": numFailed,
			"startTime": startTime,
		}).Debug("join not yet complete")

		j.delayer.delay()
	}

	j.node.EmitEvent(JoinCompleteEvent{
		Duration:  time.Now().Sub(startTime),
		NumJoined: numJoined,
		Joined:    nodesJoined,
	})

	return nodesJoined, nil
}