Broadcast Web Push subscriptions in a new goroutine

downstream.go

@@ -3060,7 +3060,7 @@ func (dc *downstreamConn) handleMessageRegistered(ctx context.Context, msg *irc.
 			// TODO: only broadcast if draft/read-marker has been negotiated
 			// TODO: use lower priority
 			network.pushTargets.Del(entity)
-			network.broadcastWebPush(ctx, &irc.Message{
+			go network.broadcastWebPush(&irc.Message{
 				Command: "MARKREAD",
 				Params:  []string{entity, timestampStr},
 			})

upstream.go

@@ -547,7 +547,7 @@ func (uc *upstreamConn) handleMessage(ctx context.Context, msg *irc.Message) err
 		}
 
 		if highlight || uc.isOurNick(target) {
-			uc.network.broadcastWebPush(ctx, msg)
+			go uc.network.broadcastWebPush(msg)
 			uc.network.pushTargets.Add(bufferName)
 		}
 
@@ -1551,7 +1551,7 @@ func (uc *upstreamConn) handleMessage(ctx context.Context, msg *irc.Message) err
 		})
 
 		if weAreInvited {
-			uc.network.broadcastWebPush(ctx, msg)
+			go uc.network.broadcastWebPush(msg)
 		}
 	case irc.RPL_INVITING:
 		var nick, channel string

user.go

@@ -456,7 +456,14 @@ func (net *network) autoSaveSASLPlain(ctx context.Context, username, password st
 	}
 }
 
-func (net *network) broadcastWebPush(ctx context.Context, msg *irc.Message) {
+// broadcastWebPush broadcasts a Web Push message for the given IRC message.
+//
+// Broadcasting the message to all Web Push endpoints might take a while, so
+// callers should call this function in a new goroutine.
+func (net *network) broadcastWebPush(msg *irc.Message) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+
 	subs, err := net.user.srv.db.ListWebPushSubscriptions(ctx, net.user.ID, net.ID)
 	if err != nil {
 		net.logger.Printf("failed to list Web push subscriptions: %v", err)