center

type Change struct {
	OldValue   string
	NewValue   string
	ChangeType ChangeType
}

type ChangeEvent struct {
	Source ChangeEventSource
	// Namespace means
	//   Namespace in Apollo
	//   Path in Etcd
	Namespace string
	Changes   map[string]*Change
}

type ChangeEventSource int

type ChangeType int

type ConfigCenter interface {
	Init(ctx context.Context, serviceName string, namespaceNames []string) error
	Stop(ctx context.Context) error

	SubscribeNamespaces(ctx context.Context, namespaceNames []string) error

	GetString(ctx context.Context, key string) (string, bool)
	GetStringWithNamespace(ctx context.Context, namespace, key string) (string, bool)
	GetBool(ctx context.Context, key string) (bool, bool)
	GetBoolWithNamespace(ctx context.Context, namespace, key string) (bool, bool)
	GetInt(ctx context.Context, key string) (int, bool)
	GetIntWithNamespace(ctx context.Context, namespace, key string) (int, bool)
	GetAllKeys(ctx context.Context) []string
	GetAllKeysWithNamespace(ctx context.Context, namespace string) []string

	Unmarshal(ctx context.Context, v interface{}) error
	UnmarshalWithNamespace(ctx context.Context, namespace string, v interface{}) error
	UnmarshalKey(ctx context.Context, key string, v interface{}) error
	UnmarshalKeyWithNamespace(ctx context.Context, namespace string, key string, v interface{}) error

	StartWatchUpdate(ctx context.Context)
	RegisterObserver(ctx context.Context, observer ConfigObserver) (recall func())
}

type ConfigCenterType int

type ConfigObserver interface {
	HandleChangeEvent(event *ChangeEvent)
}