Golang watch.NewQueue函數代碼示例

// New returns Dispatcher with cluster interface(usually raft.Node).
// NOTE: each handler which does something with raft must add to Dispatcher.wg
func New(cluster Cluster, c *Config) *Dispatcher {
	return &Dispatcher{
		nodes:                     newNodeStore(c.HeartbeatPeriod, c.HeartbeatEpsilon, c.GracePeriodMultiplier, c.RateLimitPeriod),
		store:                     cluster.MemoryStore(),
		cluster:                   cluster,
		mgrQueue:                  watch.NewQueue(16),
		keyMgrQueue:               watch.NewQueue(16),
		taskUpdates:               make(map[string]*api.TaskStatus),
		processTaskUpdatesTrigger: make(chan struct{}, 1),
		config: c,
	}
}

// New returns Dispatcher with cluster interface(usually raft.Node).
// NOTE: each handler which does something with raft must add to Dispatcher.wg
func New(cluster Cluster, c *Config) *Dispatcher {
	return &Dispatcher{
		addr:                      c.Addr,
		nodes:                     newNodeStore(c.HeartbeatPeriod, c.HeartbeatEpsilon, c.GracePeriodMultiplier),
		store:                     cluster.MemoryStore(),
		cluster:                   cluster,
		mgrQueue:                  watch.NewQueue(16),
		keyMgrQueue:               watch.NewQueue(16),
		lastSeenManagers:          getWeightedPeers(cluster),
		taskUpdates:               make(map[string]*api.TaskStatus),
		processTaskUpdatesTrigger: make(chan struct{}, 1),
		config: c,
	}
}

// NewCluster creates a new Cluster neighbors
// list for a raft Member
func NewCluster() *Cluster {
	// TODO(abronan): generate Cluster ID for federation

	return &Cluster{
		members:        make(map[uint64]*Member),
		removed:        make(map[uint64]bool),
		PeersBroadcast: watch.NewQueue(),
	}
}

// NewNode generates a new Raft node
func NewNode(opts NodeOptions) *Node {
	cfg := opts.Config
	if cfg == nil {
		cfg = DefaultNodeConfig()
	}
	if opts.TickInterval == 0 {
		opts.TickInterval = time.Second
	}
	if opts.SendTimeout == 0 {
		opts.SendTimeout = 2 * time.Second
	}

	raftStore := raft.NewMemoryStorage()

	n := &Node{
		cluster:   membership.NewCluster(2 * cfg.ElectionTick),
		raftStore: raftStore,
		opts:      opts,
		Config: &raft.Config{
			ElectionTick:    cfg.ElectionTick,
			HeartbeatTick:   cfg.HeartbeatTick,
			Storage:         raftStore,
			MaxSizePerMsg:   cfg.MaxSizePerMsg,
			MaxInflightMsgs: cfg.MaxInflightMsgs,
			Logger:          cfg.Logger,
		},
		doneCh:              make(chan struct{}),
		removeRaftCh:        make(chan struct{}),
		stopped:             make(chan struct{}),
		leadershipBroadcast: watch.NewQueue(),
		lastSendToMember:    make(map[uint64]chan struct{}),
	}
	n.memoryStore = store.NewMemoryStore(n)

	if opts.ClockSource == nil {
		n.ticker = clock.NewClock().NewTicker(opts.TickInterval)
	} else {
		n.ticker = opts.ClockSource.NewTicker(opts.TickInterval)
	}

	n.reqIDGen = idutil.NewGenerator(uint16(n.Config.ID), time.Now())
	n.wait = newWait()

	n.removeRaftFunc = func(n *Node) func() {
		var removeRaftOnce sync.Once
		return func() {
			removeRaftOnce.Do(func() {
				close(n.removeRaftCh)
			})
		}
	}(n)

	return n
}

// NewCluster creates a new Cluster neighbors list for a raft Member.
// Member marked as inactive if there was no call ReportActive for heartbeatInterval.
func NewCluster(heartbeatTicks int) *Cluster {
	// TODO(abronan): generate Cluster ID for federation

	return &Cluster{
		members:        make(map[uint64]*Member),
		removed:        make(map[uint64]bool),
		deferedConns:   make(map[*deferredConn]struct{}),
		heartbeatTicks: heartbeatTicks,
		PeersBroadcast: watch.NewQueue(),
	}
}

// NewMemoryStore returns an in-memory store. The argument is an optional
// Proposer which will be used to propagate changes to other members in a
// cluster.
func NewMemoryStore(proposer state.Proposer) *MemoryStore {
	memDB, err := memdb.NewMemDB(schema)
	if err != nil {
		// This shouldn't fail
		panic(err)
	}

	return &MemoryStore{
		memDB:    memDB,
		queue:    watch.NewQueue(0),
		proposer: proposer,
	}
}

// NewNode generates a new Raft node
func NewNode(ctx context.Context, opts NewNodeOptions) *Node {
	cfg := opts.Config
	if cfg == nil {
		cfg = DefaultNodeConfig()
	}
	if opts.TickInterval == 0 {
		opts.TickInterval = time.Second
	}

	raftStore := raft.NewMemoryStorage()

	ctx, cancel := context.WithCancel(ctx)

	n := &Node{
		Ctx:            ctx,
		cancel:         cancel,
		cluster:        membership.NewCluster(),
		tlsCredentials: opts.TLSCredentials,
		raftStore:      raftStore,
		Address:        opts.Addr,
		opts:           opts,
		Config: &raft.Config{
			ElectionTick:    cfg.ElectionTick,
			HeartbeatTick:   cfg.HeartbeatTick,
			Storage:         raftStore,
			MaxSizePerMsg:   cfg.MaxSizePerMsg,
			MaxInflightMsgs: cfg.MaxInflightMsgs,
			Logger:          cfg.Logger,
		},
		stopCh:              make(chan struct{}),
		doneCh:              make(chan struct{}),
		removeRaftCh:        make(chan struct{}),
		StateDir:            opts.StateDir,
		joinAddr:            opts.JoinAddr,
		sendTimeout:         2 * time.Second,
		leadershipBroadcast: watch.NewQueue(),
	}
	n.memoryStore = store.NewMemoryStore(n)

	if opts.ClockSource == nil {
		n.ticker = clock.NewClock().NewTicker(opts.TickInterval)
	} else {
		n.ticker = opts.ClockSource.NewTicker(opts.TickInterval)
	}
	if opts.SendTimeout != 0 {
		n.sendTimeout = opts.SendTimeout
	}

	n.reqIDGen = idutil.NewGenerator(uint16(n.Config.ID), time.Now())
	n.wait = newWait()

	n.removeRaftFunc = func(n *Node) func() {
		var removeRaftOnce sync.Once
		return func() {
			removeRaftOnce.Do(func() {
				close(n.removeRaftCh)
			})
		}
	}(n)

	return n
}

// Run runs dispatcher tasks which should be run on leader dispatcher.
// Dispatcher can be stopped with cancelling ctx or calling Stop().
func (d *Dispatcher) Run(ctx context.Context) error {
	d.mu.Lock()
	if d.isRunning() {
		d.mu.Unlock()
		return errors.New("dispatcher is already running")
	}
	ctx = log.WithModule(ctx, "dispatcher")
	if err := d.markNodesUnknown(ctx); err != nil {
		log.G(ctx).Errorf(`failed to move all nodes to "unknown" state: %v`, err)
	}
	configWatcher, cancel, err := store.ViewAndWatch(
		d.store,
		func(readTx store.ReadTx) error {
			clusters, err := store.FindClusters(readTx, store.ByName(store.DefaultClusterName))
			if err != nil {
				return err
			}
			if err == nil && len(clusters) == 1 {
				heartbeatPeriod, err := ptypes.Duration(clusters[0].Spec.Dispatcher.HeartbeatPeriod)
				if err == nil && heartbeatPeriod > 0 {
					d.config.HeartbeatPeriod = heartbeatPeriod
				}
				if clusters[0].NetworkBootstrapKeys != nil {
					d.networkBootstrapKeys = clusters[0].NetworkBootstrapKeys
				}
			}
			return nil
		},
		state.EventUpdateCluster{},
	)
	if err != nil {
		d.mu.Unlock()
		return err
	}
	// set queues here to guarantee that Close will close them
	d.mgrQueue = watch.NewQueue()
	d.keyMgrQueue = watch.NewQueue()

	peerWatcher, peerCancel := d.cluster.SubscribePeers()
	defer peerCancel()
	d.lastSeenManagers = getWeightedPeers(d.cluster)

	defer cancel()
	d.ctx, d.cancel = context.WithCancel(ctx)
	d.mu.Unlock()

	publishManagers := func(peers []*api.Peer) {
		var mgrs []*api.WeightedPeer
		for _, p := range peers {
			mgrs = append(mgrs, &api.WeightedPeer{
				Peer:   p,
				Weight: remotes.DefaultObservationWeight,
			})
		}
		d.mu.Lock()
		d.lastSeenManagers = mgrs
		d.mu.Unlock()
		d.mgrQueue.Publish(mgrs)
	}

	batchTimer := time.NewTimer(maxBatchInterval)
	defer batchTimer.Stop()

	for {
		select {
		case ev := <-peerWatcher:
			publishManagers(ev.([]*api.Peer))
		case <-d.processUpdatesTrigger:
			d.processUpdates()
			batchTimer.Reset(maxBatchInterval)
		case <-batchTimer.C:
			d.processUpdates()
			batchTimer.Reset(maxBatchInterval)
		case v := <-configWatcher:
			cluster := v.(state.EventUpdateCluster)
			d.mu.Lock()
			if cluster.Cluster.Spec.Dispatcher.HeartbeatPeriod != nil {
				// ignore error, since Spec has passed validation before
				heartbeatPeriod, _ := ptypes.Duration(cluster.Cluster.Spec.Dispatcher.HeartbeatPeriod)
				if heartbeatPeriod != d.config.HeartbeatPeriod {
					// only call d.nodes.updatePeriod when heartbeatPeriod changes
					d.config.HeartbeatPeriod = heartbeatPeriod
					d.nodes.updatePeriod(d.config.HeartbeatPeriod, d.config.HeartbeatEpsilon, d.config.GracePeriodMultiplier)
				}
			}
			d.networkBootstrapKeys = cluster.Cluster.NetworkBootstrapKeys
			d.mu.Unlock()
			d.keyMgrQueue.Publish(cluster.Cluster.NetworkBootstrapKeys)
		case <-d.ctx.Done():
			return nil
		}
	}
}