wip: migrate to mono-repo. SPN has already been moved to spn/

spn/captain/gossip.go

@@ -0,0 +1,38 @@
+package captain
+
+import (
+	"sync"
+)
+
+var (
+	gossipOps     = make(map[string]*GossipOp)
+	gossipOpsLock sync.RWMutex
+)
+
+func registerGossipOp(craneID string, op *GossipOp) {
+	gossipOpsLock.Lock()
+	defer gossipOpsLock.Unlock()
+
+	gossipOps[craneID] = op
+}
+
+func deleteGossipOp(craneID string) {
+	gossipOpsLock.Lock()
+	defer gossipOpsLock.Unlock()
+
+	delete(gossipOps, craneID)
+}
+
+func gossipRelayMsg(receivedFrom string, msgType GossipMsgType, data []byte) {
+	gossipOpsLock.RLock()
+	defer gossipOpsLock.RUnlock()
+
+	for craneID, gossipOp := range gossipOps {
+		// Don't return same msg back to sender.
+		if craneID == receivedFrom {
+			continue
+		}
+
+		gossipOp.sendMsg(msgType, data)
+	}
+}