SSE Over QUIC

Implementation of Server Sent Events by QUIC. A faster replacement for traditional SSE over HTTP/2.

Installation

go get github.com/snapp-incubator/qsse

Basic Usage

Server

// Server
package main

import "github.com/snapp-incubator/qsse"

var (
    people = []Person{...}
    accounts = []Account{...}
) 

func main() {
	topics := []string{"people", "account"}

	server, err := qsse.NewServer("localhost:4242", topics, nil)
	if err != nil {
		panic(err)
	}

	// publish events
	server.Publish("people", people[0])
	server.Publish("accounts", accounts[0])
	// ...

	// some blocking code to keep the server up
}

Client

package main

import "github.com/snapp-incubator/qsse"

func main() {
    topics := []string{"people", "account"}
    
    client, err := qsse.NewClient("localhost:4242", topics, nil)
    if err != nil {
        panic(err)
    }
	
    client.SetEventHandler("people", func(data []byte) {
        // handle data on topic
    })
	
    client.SetErrorHandler(func(code int, data map[string]any) { 
        // handle different error
    })

	// some blocking code to keep the client up for receiving the events
}

Security

By default, all the clients are accepted. Use Authentication to check is new clients are valid and use Authorization to check client access on each topic.

// authentication

// func
server.SetAuthenticatorFunc(func(token string) bool {

})
// interface
server.SetAuthenticator()

// authorization on each topic

// func
server.SetAuthorizerFunc(func(token, topic string) bool {

})
// interface
server.SetAuthorizer()

Topic Patterns

topics can be separated by . logically. also * can be used as wildcard placeholder. for example these are valid topics

• ride
• ride.*.start
• ride.passenger.*

Note: Putting * at the end of topic will publish or subscribe to every topic that start with * prefix. For example ride.passenger.* is equivalent of subscribing to ride.passenger.start, ride.passenger.account.name, and so on.

Server Configurations

config	description	default
Metric.namespace, Metric.subsystem	namespace and subsystem parameters of the Prometheus metrics	"qsse", "qsse"
TLSConfig	TLS config of server	qsse.GetDefaultTLSConfig ()
Worker.CleaningInterval	interval between cleaning idle clients	10 sec
Worker.ClientAcceptorCount	number of Goroutine accepting new clients	1
Worker.ClientAcceptorQueueSize	queue size of client acceptors. (this is usually equal to clientAcceptorCount)	1
Worker.EventDistributorCount	number of concurrent goroutine distributing events to subscribers for each EventSource[topic]	1
Worker.EventDistributorQueueSize	queue size of event distribution work	10

Client Configurations

config	description	default
token	token that will be send to server on the initial connection to verify the client.	""
TLSConfig	TLS config of client	qsse.GetSimpleTLS ()
ReconnectPolicy.Retry	bool that indicate if client should retry connection if couldn't connect to server on the first try.	false
ReconnectPolicy.RetryTimes	number of reconnect times to connect.	5
ReconnectPolicy.RetryInterval	interval between reconnecting to server	5 sec

Examples

• Simple Client & Server
• Topic Patterns
• Multiple Generators