使用已发布消息阻塞NetMQ订阅者

本文关键字：NetMQ 消息 布消息 | 更新日期: 2023-09-27 18:19:15

我有一个消息发布服务器类，它在构造时创建一个PUB套接字，代码如下:

this.context = NetMQContext.Create();
this.pubSocket = this.context.CreatePublisherSocket();
var portNumber = this.installerSettings.PublisherPort;
this.pubSocket.Bind("tcp://127.0.0.1:" + portNumber);

使用messagePublishingServer.Publish(message)发送消息执行:

this.pubSocket.SendMoreFrame(string.Empty).SendFrame(message);

下面的xBehave test…

    [Scenario]
    public void PublishMessageScenario()
    {
        MessagePublishingServer messagePublishingServer = null;
        NetMQContext context;
        NetMQ.Sockets.SubscriberSocket subSocket = null;
        string receivedMessage = null;
        "Given a running message publishing server"._(() =>
        {
            var installerSettingsManager = A.Fake<IInstallerSettingsManager>();
            var settings = new InstallerSettings { PublisherPort = "5348" };
            A.CallTo(() => installerSettingsManager.Settings).Returns(settings);
            messagePublishingServer = new MessagePublishingServer(installerSettingsManager);
        });
        "And a subscriber connected to the publishing server"._(() =>
        {
            context = NetMQContext.Create();
            subSocket = context.CreateSubscriberSocket();
            subSocket.Options.ReceiveHighWatermark = 1000;
            subSocket.Connect("tcp://127.0.0.1:5348");
            subSocket.Subscribe(string.Empty);
        });
        "When publishing a message"._(() =>
        {
            messagePublishingServer.Publish("test message");
            // Receive the topic
            subSocket.ReceiveFrameString();
            // and the message
            receivedMessage = subSocket.ReceiveFrameString();
        });
        "Then the subscriber must have received it"._(() =>
        {
            receivedMessage.Should().NotBeNullOrEmpty();
            receivedMessage.Should().Be("test message");
        });
    }

…第一个subSocket.ReceiveFrameString()中的块，这是我意想不到的。订阅者套接字不应该将发布的消息排队，直到调用接收?

使用已发布消息阻塞NetMQ订阅者

发布者就像收音机，如果您在发布者发布时没有连接和订阅，您就会错过消息。我的建议是在用户连接后设置100毫秒的睡眠时间(仅用于测试)。

从源(ReceivingSocketExtensions.cs .): 

    /// Receive a single frame from socket, blocking until one arrives, and decode as a string using ...
    public static string ReceiveFrameString([NotNull] this IReceivingSocket socket)

和

    /// If no message is immediately available, return <c>false</c>.
    public static bool TryReceiveFrameString([NotNull] this IReceivingSocket socket, out string frameString)
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