Method ReplicaTouch

onecache/onecache_rpc.go:380–402

ReplicaTouch is used for setting the expiration of a key on a replica. It allows setting the version of the key so that only the most updated version of the value is stored.

(args ReplicaStorageArgs, resp *struct{})

// allows setting the version of the key so that only the most updated version
// of the value is stored.
func (r *rpcServer) ReplicaTouch(args ReplicaStorageArgs, resp *struct{}) error {
	target := r.targetNode(args.Key, args.ExplicitPeer)
	if target != r.n.name {
		return r.forward(target, "Node.ReplicaTouch", args, resp)
	}

	r.l.Lock()
	defer r.l.Unlock()
	v := r.versions[args.Key]

	// Check if we are trying to set an old version.
	if v != nil && v.Peer == args.Peer && args.Version <= v.Version {
		return nil
	}

	if err := r.n.data.Touch(args.Key, args.Exp); err != nil {
		return err
	}

	// Update the replica version.
	r.versions[args.Key] = &args.ReplicaVersion
	return nil
}