1 files changed, 61 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/memberlist/event_delegate.go b/vendor/github.com/hashicorp/memberlist/event_delegate.go
new file mode 100644
index 000000000..35e2a56fd
--- /dev/null
+++ b/vendor/github.com/hashicorp/memberlist/event_delegate.go
@@ -0,0 +1,61 @@
+package memberlist
+
+// EventDelegate is a simpler delegate that is used only to receive
+// notifications about members joining and leaving. The methods in this
+// delegate may be called by multiple goroutines, but never concurrently.
+// This allows you to reason about ordering.
+type EventDelegate interface {
+	// NotifyJoin is invoked when a node is detected to have joined.
+	// The Node argument must not be modified.
+	NotifyJoin(*Node)
+
+	// NotifyLeave is invoked when a node is detected to have left.
+	// The Node argument must not be modified.
+	NotifyLeave(*Node)
+
+	// NotifyUpdate is invoked when a node is detected to have
+	// updated, usually involving the meta data. The Node argument
+	// must not be modified.
+	NotifyUpdate(*Node)
+}
+
+// ChannelEventDelegate is used to enable an application to receive
+// events about joins and leaves over a channel instead of a direct
+// function call.
+//
+// Care must be taken that events are processed in a timely manner from
+// the channel, since this delegate will block until an event can be sent.
+type ChannelEventDelegate struct {
+	Ch chan<- NodeEvent
+}
+
+// NodeEventType are the types of events that can be sent from the
+// ChannelEventDelegate.
+type NodeEventType int
+
+const (
+	NodeJoin NodeEventType = iota
+	NodeLeave
+	NodeUpdate
+)
+
+// NodeEvent is a single event related to node activity in the memberlist.
+// The Node member of this struct must not be directly modified. It is passed
+// as a pointer to avoid unnecessary copies. If you wish to modify the node,
+// make a copy first.
+type NodeEvent struct {
+	Event NodeEventType
+	Node  *Node
+}
+
+func (c *ChannelEventDelegate) NotifyJoin(n *Node) {
+	c.Ch <- NodeEvent{NodeJoin, n}
+}
+
+func (c *ChannelEventDelegate) NotifyLeave(n *Node) {
+	c.Ch <- NodeEvent{NodeLeave, n}
+}
+
+func (c *ChannelEventDelegate) NotifyUpdate(n *Node) {
+	c.Ch <- NodeEvent{NodeUpdate, n}
+}