nats

Documentation

Index

• Variables
• func Addr(addr string) nats.Option
• func ReplyServer(msg *protos.ReplyMessage) error
• func UserInfo(user, password string) nats.Option
• func With(options nats.Options) nats.Option
• type StackExchange
  • func NewStackExchange(cfg StackExchangeCfgs, options ...nats.Option) (*StackExchange, error)
  • func (exc *StackExchange) Ask(ctx context.Context, msg wolfsocket.Message, token string) (response wolfsocket.Message, err error)
  • func (exc *StackExchange) AskServer(ctx context.Context, channel string, msg protos.ServerMessage) (response *protos.ReplyMessage, err error)
  • func (exc *StackExchange) NotifyAsk(msg wolfsocket.Message, token string) error
  • func (exc *StackExchange) OnConnect(c *wolfsocket.Conn) error
  • func (exc *StackExchange) OnDisconnect(c *wolfsocket.Conn)
  • func (exc *StackExchange) Publish(channel string, msgs []protos.ServerMessage) error
  • func (exc *StackExchange) Reply(err error, token string) error
  • func (exc *StackExchange) Subscribe(c *wolfsocket.Conn, channel string)
  • func (exc *StackExchange) Unsubscribe(c *wolfsocket.Conn, channel string)
• type StackExchangeCfgs

Variables

var (
	ErrChannelEmpty = errors.New("We do not accept messages with empty channel")

	// InvalidPrefix is returned when a message with a channel prefix
	// that does not match the expected prefix is received during subscription.
	// The message is not executed to prevent unauthorized access or incorrect behavior.
	InvalidPrefix = errors.New("message received with invalid prefix")
)

Functions

func Addr

func Addr(addr string) nats.Option

func ReplyServer

func ReplyServer(msg *protos.ReplyMessage) error

func UserInfo

func UserInfo(user, password string) nats.Option

func With

func With(options nats.Options) nats.Option

With accepts a nats.Options structure which contains the whole configuration and returns a nats.Option which can be passed to the `NewStackExchange`'s second input variadic argument. Note that use this method only when you want to override the default options at once.

Types

type StackExchange

type StackExchange struct {

	// If you use the same nats server instance for multiple wolfsocket apps,
	// set this to different values across your apps.
	SubjectPrefix string
	// contains filtered or unexported fields
}

StackExchange is a `wolfsocket.StackExchange` for nats based on https://nats-io.github.io/docs/developer/tutorials/pubsub.html.

func NewStackExchange

func NewStackExchange(cfg StackExchangeCfgs, options ...nats.Option) (*StackExchange, error)

NewStackExchange returns a new nats StackExchange. The required field is "url" which should be in the form of nats connection string, e.g. nats://username:pass@localhost:4222. Other option is to leave the url with localhost:4222 and pass authentication options such as `nats.UserInfo(username, pass)` or nats.UserCredentials("./userCredsFile") at the second variadic input argument.

Options can be used to register nats error and close handlers too.

Alternatively, use the `With(nats.Options)` function to customize the client through struct fields.

func (*StackExchange) Ask

func (exc *StackExchange) Ask(ctx context.Context, msg wolfsocket.Message, token string) (response wolfsocket.Message, err error)

Ask implements server Ask for nats. It blocks.

func (*StackExchange) AskServer

func (exc *StackExchange) AskServer(ctx context.Context, channel string, msg protos.ServerMessage) (response *protos.ReplyMessage, err error)

func (*StackExchange) NotifyAsk

func (exc *StackExchange) NotifyAsk(msg wolfsocket.Message, token string) error

NotifyAsk notifies and unblocks a "msg" subscriber, called on a server connection's read when expects a result.

func (*StackExchange) OnConnect

func (exc *StackExchange) OnConnect(c *wolfsocket.Conn) error

OnConnect prepares the connection nats subscriber and subscribes to itself for direct wolfsocket messages. It's called automatically after the wolfsocket server's OnConnect (if any) on incoming client connections.

func (*StackExchange) OnDisconnect

func (exc *StackExchange) OnDisconnect(c *wolfsocket.Conn)

OnDisconnect terminates the connection's subscriber that created on the `OnConnect` method. It unsubscribes to all opened channels and closes the internal read messages channel. It's called automatically when a connection goes offline, manually by server or client or by network failure.

func (*StackExchange) Publish

func (exc *StackExchange) Publish(channel string, msgs []protos.ServerMessage) error

func (*StackExchange) Reply

func (exc *StackExchange) Reply(err error, token string) error

reply ask message

func (*StackExchange) Subscribe

func (exc *StackExchange) Subscribe(c *wolfsocket.Conn, channel string)

Subscribe subscribes to a specific channel, it's called automatically on wolfsocket namespace connected.

func (*StackExchange) Unsubscribe

func (exc *StackExchange) Unsubscribe(c *wolfsocket.Conn, channel string)

Unsubscribe unsubscribes from a specific channel, it's called automatically on wolfsocket namespace disconnect.

type StackExchangeCfgs

type StackExchangeCfgs struct {
	SubjectPrefix string
	wolfsocket.Namespaces
	*wolfsocket.Server
}