discovery

type Backend interface {
	// Type returns the backend provider type.
	Type() string

	// Set value for the specified key with a specified ttl.
	Set(key, value string, ttl time.Duration) error

	// Get the value of the specified key or directory.
	Get(key string, dir bool) (*KVPairs, error)

	// Incr invokes an atomic value increase for the specified key.
	Incr(key string) (int64, error)

	// Watch for changes of the specified key or directory.
	Watch(key string, version uint64, dir bool) (EventChan, error)

	// KeepAlive sets value and updates the ttl for the specified key.
	KeepAlive(key, value string, ttl time.Duration) error

	// Close the provider connection.
	Close()
}

type Discovery interface {
	// PassthroughAddr returns service unique ID and rpc address registered for the component.
	PassthroughAddr(component string) (int64, string)

	// Register rpc address of the component service address.
	Register(component, addr string, opts ...Option) (int64, error)

	// GetAddresses returns rpc service addresses.
	GetAddresses(service string) []resolver.Address
}

type EventChan chan *WatchEvent

type EventType int

type KVPair struct {
	Key     string
	Value   string
	Version uint64
}

type KVPairs struct {
	KVs     []*KVPair
	Version uint64
}

type Option func(options *Options)

type Options struct {
	Isolate  bool
	TTL      time.Duration
	Services []string
}

type WatchEvent struct {
	EventType
	KVPair
}