func newJoinSender()

in swim/join_sender.go [118:168]
34 lines of code
7 McCabe index (conditional complexity)

func newJoinSender(node *Node, opts *joinOpts) (*joinSender, error) {
	if opts == nil {
		opts = &joinOpts{}
	}

	if node.discoverProvider == nil {
		return nil, errors.New("no discover provider")
	}

	// Resolve/retrieve bootstrap hosts from the provider specified in the
	// join options.
	bootstrapHosts, err := node.discoverProvider.Hosts()
	if err != nil {
		return nil, err
	}

	// Check we're in the bootstrap host list and add ourselves if we're not
	// there. If the host list is empty, this will create a single-node
	// cluster.
	if !util.StringInSlice(bootstrapHosts, node.Address()) {
		bootstrapHosts = append(bootstrapHosts, node.Address())
	}

	js := &joinSender{
		node:   node,
		logger: logging.Logger("join").WithField("local", node.Address()),
	}

	// Parse bootstrap hosts into a map
	js.parseHosts(bootstrapHosts)

	js.potentialNodes = js.CollectPotentialNodes(nil)

	js.timeout = util.SelectDuration(opts.timeout, defaultJoinTimeout)
	js.maxJoinDuration = util.SelectDuration(opts.maxJoinDuration, defaultMaxJoinDuration)
	js.parallelismFactor = util.SelectInt(opts.parallelismFactor, defaultParallelismFactor)
	js.size = util.SelectInt(opts.size, defaultJoinSize)
	js.size = util.Min(js.size, len(js.potentialNodes))
	js.delayer = opts.delayer

	if js.delayer == nil {
		// Create and use exponential delayer as the delay mechanism. Create it
		// with nil opts which uses default delayOpts.
		js.delayer, err = newExponentialDelayer(js.node.address, nil)
		if err != nil {
			return nil, err
		}
	}

	return js, nil
}