mapper: produce map before poll (#2628)

hscontrol/mapper/utils.go

@@ -0,0 +1,47 @@
+package mapper
+
+import "tailscale.com/tailcfg"
+
+// mergePatch takes the current patch and a newer patch
+// and override any field that has changed.
+func mergePatch(currPatch, newPatch *tailcfg.PeerChange) {
+	if newPatch.DERPRegion != 0 {
+		currPatch.DERPRegion = newPatch.DERPRegion
+	}
+
+	if newPatch.Cap != 0 {
+		currPatch.Cap = newPatch.Cap
+	}
+
+	if newPatch.CapMap != nil {
+		currPatch.CapMap = newPatch.CapMap
+	}
+
+	if newPatch.Endpoints != nil {
+		currPatch.Endpoints = newPatch.Endpoints
+	}
+
+	if newPatch.Key != nil {
+		currPatch.Key = newPatch.Key
+	}
+
+	if newPatch.KeySignature != nil {
+		currPatch.KeySignature = newPatch.KeySignature
+	}
+
+	if newPatch.DiscoKey != nil {
+		currPatch.DiscoKey = newPatch.DiscoKey
+	}
+
+	if newPatch.Online != nil {
+		currPatch.Online = newPatch.Online
+	}
+
+	if newPatch.LastSeen != nil {
+		currPatch.LastSeen = newPatch.LastSeen
+	}
+
+	if newPatch.KeyExpiry != nil {
+		currPatch.KeyExpiry = newPatch.KeyExpiry
+	}
+}