GoTomato/internal/websocket/staleClients.go

package websocket

import (
	"time"

	"github.com/gorilla/websocket"

	"git.smsvc.net/pomodoro/GoTomato/pkg/models"
)

// Checks if the websockets last Pong is recent
func isStale(client *models.WebsocketClient) bool {
	return time.Since(client.LastPong) > (TIMEOUT * time.Second)
}

// send a Ping to the websocket client
func sendPing(client *models.WebsocketClient) bool {
	client.Conn.SetWriteDeadline(time.Now().Add(TIMEOUT * time.Second))
	err := client.Conn.WriteMessage(websocket.PingMessage, nil)
	if err != nil {
		return false
	}
	return true
}

// Check and remove stale clients
func RemoveStaleClients() {
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()

	for range ticker.C {
		mu.Lock()
		for _, client := range Clients {
			// send ping
			if !sendPing(client) {
				client.Conn.Close()
				delete(Clients, client.Conn.LocalAddr())
			}

			// check for last pong
			if isStale(client) {
				client.Conn.Close()
				delete(Clients, client.Conn.LocalAddr())
			}
		}
		mu.Unlock()
	}
}