60 lines
1.5 KiB
Go
60 lines
1.5 KiB
Go
package element
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import (
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"github.com/hashicorp/memberlist"
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)
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// NodeEventType is the type of node event
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type NodeEventType string
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const (
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// NodeJoin is the event fired upon a node joining the cluster
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NodeJoin NodeEventType = "join"
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// NodeLeave is the event fired upon a node leaving the cluster
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NodeLeave NodeEventType = "leave"
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// NodeUpdate is the event fired upon a node updating in the cluster
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NodeUpdate NodeEventType = "update"
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)
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// NodeEvent stores the event type and node information
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type NodeEvent struct {
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// EventType is the type of event fired
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EventType NodeEventType
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// Node is the internal cluster node
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Node *memberlist.Node
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}
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// EventHandler is used for event handling
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type EventHandler struct {
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ch chan *NodeEvent
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}
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// NewEventHandler returns an EventHandler that is used to perform actions for the specified event
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func NewEventHandler(ch chan *NodeEvent) *EventHandler {
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return &EventHandler{
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ch: ch,
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}
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}
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// NotifyJoin notifies when a node joins the cluster
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func (h *EventHandler) NotifyJoin(n *memberlist.Node) {
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go h.notify(NodeJoin, n)
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}
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// NotifyLeave notifies when a node leaves the cluster
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func (h *EventHandler) NotifyLeave(n *memberlist.Node) {
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go h.notify(NodeLeave, n)
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}
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// NotifyUpdate notifies when a node is updated in the cluster
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func (h *EventHandler) NotifyUpdate(n *memberlist.Node) {
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go h.notify(NodeUpdate, n)
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}
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func (h *EventHandler) notify(t NodeEventType, n *memberlist.Node) {
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// TODO: use context WithTimeout to enable cancel
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h.ch <- &NodeEvent{
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EventType: t,
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Node: n,
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}
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}
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