func newConn()

in conn.go [255:320]
63 lines of code
18 McCabe index (conditional complexity)

func newConn(netConn net.Conn, opts *ConnOptions) (*Conn, error) {
	c := &Conn{
		dialer:            defaultDialer{},
		net:               netConn,
		maxFrameSize:      defaultMaxFrameSize,
		peerMaxFrameSize:  defaultMaxFrameSize,
		channelMax:        defaultMaxSessions - 1, // -1 because channel-max starts at zero
		idleTimeout:       defaultIdleTimeout,
		containerID:       shared.RandString(40),
		done:              make(chan struct{}),
		rxtxExit:          make(chan struct{}),
		rxDone:            make(chan struct{}),
		txFrame:           make(chan frameEnvelope),
		txDone:            make(chan struct{}),
		sessionsByChannel: map[uint16]*Session{},
		writeTimeout:      defaultWriteTimeout,
	}

	// apply options
	if opts == nil {
		opts = &ConnOptions{}
	}

	if opts.WriteTimeout > 0 {
		c.writeTimeout = opts.WriteTimeout
	} else if opts.WriteTimeout < 0 {
		c.writeTimeout = 0
	}
	if opts.ContainerID != "" {
		c.containerID = opts.ContainerID
	}
	if opts.HostName != "" {
		c.hostname = opts.HostName
	}
	if opts.IdleTimeout > 0 {
		c.idleTimeout = opts.IdleTimeout
	} else if opts.IdleTimeout < 0 {
		c.idleTimeout = 0
	}
	if opts.MaxFrameSize > 0 && opts.MaxFrameSize < 512 {
		return nil, fmt.Errorf("invalid MaxFrameSize value %d", opts.MaxFrameSize)
	} else if opts.MaxFrameSize > 512 {
		c.maxFrameSize = opts.MaxFrameSize
	}
	if opts.MaxSessions > 0 {
		c.channelMax = opts.MaxSessions
	}
	if opts.SASLType != nil {
		if err := opts.SASLType(c); err != nil {
			return nil, err
		}
	}
	if opts.Properties != nil {
		c.properties = make(map[encoding.Symbol]any)
		for key, val := range opts.Properties {
			c.properties[encoding.Symbol(key)] = val
		}
	}
	if opts.TLSConfig != nil {
		c.tlsConfig = opts.TLSConfig.Clone()
	}
	if opts.dialer != nil {
		c.dialer = opts.dialer
	}
	return c, nil
}