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89 lines
2.3 KiB
89 lines
2.3 KiB
package peernotifier |
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import ( |
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"sync" |
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"github.com/lightningnetwork/lnd/subscribe" |
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) |
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// PeerNotifier is a subsystem which observes peer offline and online events. |
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// It takes subscriptions for its events, and whenever it observes a new event |
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// it notifies its subscribers over the proper channel. |
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type PeerNotifier struct { |
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started sync.Once |
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stopped sync.Once |
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ntfnServer *subscribe.Server |
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} |
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// PeerOnlineEvent represents a new event where a peer comes online. |
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type PeerOnlineEvent struct { |
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// PubKey is the peer's compressed public key. |
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PubKey [33]byte |
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} |
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// PeerOfflineEvent represents a new event where a peer goes offline. |
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type PeerOfflineEvent struct { |
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// PubKey is the peer's compressed public key. |
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PubKey [33]byte |
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} |
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// New creates a new peer notifier which notifies clients of peer online |
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// and offline events. |
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func New() *PeerNotifier { |
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return &PeerNotifier{ |
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ntfnServer: subscribe.NewServer(), |
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} |
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} |
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// Start starts the PeerNotifier's subscription server. |
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func (p *PeerNotifier) Start() error { |
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var err error |
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p.started.Do(func() { |
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log.Info("PeerNotifier starting") |
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err = p.ntfnServer.Start() |
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}) |
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return err |
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} |
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// Stop signals the notifier for a graceful shutdown. |
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func (p *PeerNotifier) Stop() error { |
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var err error |
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p.stopped.Do(func() { |
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log.Info("Stopping PeerNotifier") |
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err = p.ntfnServer.Stop() |
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}) |
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return err |
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} |
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// SubscribePeerEvents returns a subscribe.Client that will receive updates |
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// any time the Server is informed of a peer event. |
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func (p *PeerNotifier) SubscribePeerEvents() (*subscribe.Client, error) { |
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return p.ntfnServer.Subscribe() |
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} |
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// NotifyPeerOnline sends a peer online event to all clients subscribed to the |
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// peer notifier. |
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func (p *PeerNotifier) NotifyPeerOnline(pubKey [33]byte) { |
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event := PeerOnlineEvent{PubKey: pubKey} |
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log.Debugf("PeerNotifier notifying peer: %x online", pubKey) |
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if err := p.ntfnServer.SendUpdate(event); err != nil { |
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log.Warnf("Unable to send peer online update: %v", err) |
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} |
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} |
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// NotifyPeerOffline sends a peer offline event to all the clients subscribed |
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// to the peer notifier. |
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func (p *PeerNotifier) NotifyPeerOffline(pubKey [33]byte) { |
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event := PeerOfflineEvent{PubKey: pubKey} |
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log.Debugf("PeerNotifier notifying peer: %x offline", pubKey) |
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if err := p.ntfnServer.SendUpdate(event); err != nil { |
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log.Warnf("Unable to send peer offline update: %v", err) |
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} |
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}
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