ServiceStack OnDeserialized等效项 [英] ServiceStack OnDeserialized Equivalent

问题描述

我正在实时反序列化Websocket消息.在消息(json字符串)中，我收到一个unix时间戳(长).对每个对象进行反序列化后，我都需要它尽快调用方法，以便我可以捕获消息发送和接收之间的延迟.使用Json.NET很简单，我只是将此方法添加到了DataContract类中:

I am deserialize a websocket message in real time. In the message (string of json) I receive there is a unix timestamp (long). As soon as each object is deserialized I need it to call a method ASAP so that I can capture the delay between the time the message was sent and received. With Json.NET that was simple I just added this method to my DataContract class:

[OnDeserialized]
private void OnDeserialized(StreamingContext context)
{
    Timestamp = DateTimeOffset.FromUnixTimeMilliseconds(TimestampLong).LocalDateTime;
    Delay = DateTime.Now - Timestamp;
}

出于各种原因，我非常希望继续使用ServiceStack的反序列化器，但是我似乎无法找到一种实现此目的的方法.我确实在大约10年前找到了此StackOverflow帖子，但我希望这种情况有所改变，或者我有一个解决方法可以使用.

I would much prefer to use ServiceStack's deserializer going forward for various reasons but I can't seem to figure out a way to do this. I did find this StackOverflow post from almost 10 years ago but I'm hoping that's changed or that there is a workaround that I can use.

推荐答案

ServiceStack.Text 默认情况下不支持这些属性，但是您可以使用自定义类型配置，例如:

ServiceStack.Text doesn't support these attributes by default, but you can implement serialization callbacks with Custom Type Configuration, e.g:

JsConfig<MyType>.OnDeserializedFn = o =>
{
    o.OnDeserialized(null);
    return o;
};

SerializationHookTests.cs 显示如何使用此帮助程序使用类型过滤器为这些类型连接这些回调:

The SerializationHookTests.cs shows how you can use the Type Filters to wire up these callbacks for a type using this helper:

static void AddSerializeHooksForType<T>()
{
    Type type = typeof(T);
    System.Reflection.MethodInfo[] typeMethods = type
      .GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
    var onSerializingMethods = typeMethods.Where(m => 
        m.GetCustomAttributes(typeof(OnSerializingAttribute), true).Length > 0);
    var OnDeserializedMethods = typeMethods.Where(m => 
        m.GetCustomAttributes(typeof(OnDeserializedAttribute), true).Length > 0);
    var OnSerializedMethods = typeMethods.Where(m => 
        m.GetCustomAttributes(typeof(OnSerializedAttribute), true).Length > 0);
    Object[] Parameters = { null };

    if (onSerializingMethods.Any()) {
        ServiceStack.Text.JsConfig<T>.OnSerializingFn = s => {
            foreach (var method in onSerializingMethods)
                method.Invoke(s, Parameters);
            return s;
        };
    }
    if (OnSerializedMethods.Any()) {
        ServiceStack.Text.JsConfig<T>.OnSerializedFn = s => {
            foreach (var method in OnSerializedMethods)
                method.Invoke(s, Parameters);
        };
    }
    if (OnDeserializedMethods.Any()) {
        ServiceStack.Text.JsConfig<T>.OnDeserializedFn = s => {
            foreach (var method in OnDeserializedMethods)
                method.Invoke(s, Parameters);
            return s;
        };
    }
}

您可以通过以下方式为类型接线:

Which you can wire up for a type with:

AddSerializeHooksForType<HookTest>();

它将在其中调用所需的回调的地方，例如:

Where it will call the desired callbacks, e.g:

public class HookTest
{
    /// <summary>
    /// Will be executed when deserializing starts
    /// </summary>
    [OnDeserializing]
    protected void OnDeserializing(StreamingContext ctx) { }

    /// <summary>
    /// Will be executed when deserializing finished
    /// </summary>
    [OnDeserialized]
    protected void OnDeserialized(StreamingContext ctx) { }

    /// <summary>
    /// Will be executed when serializing starts
    /// </summary>
    [OnSerializing]
    protected void OnSerializing(StreamingContext ctx) { }

    /// <summary>
    /// Will be executed when serializing finished
    /// </summary>
    [OnSerialized]
    protected void OnSerialized(StreamingContext ctx) { }
}

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