精简后的项目：仅保留 api/ui 源码、文档、构建依赖

api/graphql/notification/Notification.go

@@ -0,0 +1,83 @@
+package notification
+
+import (
+	"errors"
+	"log"
+	"sync"
+
+	"github.com/photoview/photoview/api/graphql/models"
+)
+
+type NotificationChannel = chan<- *models.Notification
+
+type NotificationListener struct {
+	listenerID int
+	user       models.User
+	channel    NotificationChannel
+}
+
+func NewListener(user models.User, channel NotificationChannel) *NotificationListener {
+	nextNotificationId++
+	return &NotificationListener{
+		listenerID: nextNotificationId,
+		user:       user,
+		channel:    channel,
+	}
+}
+
+var notificationListeners []*NotificationListener = make([]*NotificationListener, 0)
+var nextNotificationId = 0
+var notificationLock = &sync.Mutex{}
+
+func RegisterListener(user *models.User, channel NotificationChannel) int {
+	log.Println("Registering notification listener")
+
+	notificationLock.Lock()
+	defer notificationLock.Unlock()
+
+	notificationListeners = append(notificationListeners, NewListener(*user, channel))
+	return nextNotificationId
+}
+
+func DeregisterListener(listenerID int) error {
+
+	notificationLock.Lock()
+	defer notificationLock.Unlock()
+
+	for i, listener := range notificationListeners {
+
+		log.Println("Deregistering notification listener")
+
+		if listener.listenerID == listenerID {
+
+			if len(notificationListeners) > 1 {
+				lastIndex := len(notificationListeners) - 1
+				lastListener := notificationListeners[lastIndex]
+				notificationListeners[i] = lastListener
+				notificationListeners[lastIndex] = nil
+				notificationListeners = notificationListeners[:lastIndex]
+			} else {
+				notificationListeners = make([]*NotificationListener, 0)
+			}
+
+			return nil
+		}
+	}
+
+	return errors.New("ListenerID not found, while trying to deregister it")
+}
+
+func BroadcastNotification(notification *models.Notification) {
+
+	if notification == nil {
+		return
+	}
+
+	notificationLock.Lock()
+	defer notificationLock.Unlock()
+
+	for _, listener := range notificationListeners {
+		listener.channel <- notification
+	}
+
+}