Azure Function Json 序列化问题

Question

我的自定义序列化程序在 Orchestration Functions 之间传递信息时有时会出现问题，我不知道这是因为对象的嵌套/构造方式，还是与持久化有关功能以及我如何实现序列化程序。大多数情况下，它似乎在持久客户端调用的 Ochestration 中的 Activity 调用失败。

详情如下：

所以我有一个自定义基础 class 本质上是 string Enum（它是我在 Stack Overflow 上找到的想法的汇编）

public abstract class StringEnum<T> 
    where T : StringEnum<T>
{
    public readonly string Value;

    protected StringEnum(string value)
    {
        Value = value;
    }

    public override string ToString()
    {
        return Value;
    }

    public override bool Equals(object obj)
    {
        try
        {
            return (string)obj == Value;
        }
        catch
        {
            return false;
        }
    }

    public override int GetHashCode()
    {
        return Value.GetHashCode();
    }

    public static IEnumerable<T> All
        => typeof(T).GetProperties()
            .Where(p => p.PropertyType == typeof(T))
            .Select(x => (T)x.GetValue(null, null));

    public static implicit operator string(StringEnum<T> enumObject)
    {
        return enumObject?.Value;
    }

    public static implicit operator StringEnum<T>(string stringValue)
    {
        if (All.Any(x => x.Value == stringValue))
        {
            Type t = typeof(T);
            ConstructorInfo ci = t.GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, null, new Type[] { typeof(string) }, null);
            return (T)ci.Invoke(new object[] { stringValue });
        }

        return null;
    }

    public static bool operator ==(StringEnum<T> a, StringEnum<T> b)
    {
        return a.Value == b.Value;
    }

    public static bool operator !=(StringEnum<T> a, StringEnum<T> b)
    {
        return a.Value != b.Value;
    }
}

我有两个实现：

public class ReportType : StringEnum<ReportType>, IReportType
{
    private ReportType(string value): base(value) { }
    public new string Value { get { return base.Value; } }

    public static ReportType A_Orders => new ReportType("A_GET_ORDERS");
    // ... more types
}

public class ReportStatus : StringEnum<ReportStatus>
{
    private ReportStatus(string value): base(value) { }
    public new string Value { get { return base.Value; } }

    public static ReportStatus New => new ReportStatus("New");
    public static ReportStatus Done => new ReportStatus("Done");
    // ... more types
}

我写了一个自定义 JsonConverter 来处理这个 class

的 JSON 转换

public class StringEnumJsonConverter<T> : JsonConverter<T>
    where T : StringEnum<T>
{
    public override void WriteJson(JsonWriter writer, T value, JsonSerializer serializer)
    {
        writer.WriteValue(value.ToString());
    }

    public override T ReadJson(JsonReader reader, Type objectType, T existingValue, bool hasExistingValue, JsonSerializer serializer)
    {
        string s = (string)reader.Value;
        return (T)s;
    }
}

然后我在函数启动中实现了它

[assembly: FunctionsStartup(typeof(Functions.Startup))]
namespace Functions
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddSingleton<IMessageSerializerSettingsFactory, StringEnumMessageSerializerSettingsFactory>();
        }

        internal class StringEnumMessageSerializerSettingsFactory : IMessageSerializerSettingsFactory
        {
            public JsonSerializerSettings CreateJsonSerializerSettings()
            {
                return new JsonSerializerSettings()
                {
                    Converters = new List<JsonConverter>
                    { 
                        new StringEnumJsonConverter<ReportType>(), 
                        new StringEnumJsonConverter<ReportStatus>(),
                    },
                    ContractResolver = new StringEnumResolver()
                };
            }
        }

        internal class StringEnumResolver : DefaultContractResolver
        {
            protected override JsonContract CreateContract(Type objectType)
            {
                if (objectType == typeof(ReportType))
                {
                    return GetContract(new StringEnumJsonConverter<ReportType>()), objectType);
                }
                else if (objectType == typeof(ReportStatus))
                {
                    return GetContract(new StringEnumJsonConverter<ReportStatus>(), objectType);
                }

                return base.CreateContract(objectType);
            }

            private JsonContract GetContract(JsonConverter converter, Type objectType)
            {
                var contract = base.CreateObjectContract(objectType);
                contract.Converter = converter;
                return contract;
            }
        }
    }
}

我有一个 class 使用 ReportType

public class ReportsRequestOptions
{
    public List<ReportType> ReportTypes { get; set; }
    public List<int> Ids { get; set; }
    public DateTime From { get; set; }
    public DateTime To { get; set; }
}

和 class 同时使用 ReportType 和 ReportStatus 用于 list 另一个 class

public class ReportRequest
{
    public ReportType ReportName { get; }
    public ReportStatus ReportStatus { get; set; }
    // other fields that work
}

internal class ClientReportsRequest
{
    public int Id {get; set; }
    public List<ReportRequest> Requests { get; set; }
    public DateTime To {get; set; }
    public DateTime From {get; set; }
}

当我将数据从我的 HttpTrigger 移动到我的主编排函数时我使用 ReportsRequestOptions 但是当我将 ClientReportsRequest 传递到子编排时 JsonConverter 似乎没有工作，这些值只是 Null 而不是它们通常显示的字符串。我可以在转换器中放置一个断点并看到它正在被调用，但由于某种原因，这些值没有出现在我的当地人中，所以我无法检查它以找出发生这种情况的原因。

实施：

[FunctionName(nameof(RunReportsAsync))]
public async Task<IActionResult> RunReportsAsync(
    [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)] HttpRequest req,
    [DurableClient] IDurableClient client
)
{
    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    ReportsRequestOptions requestOptions = JsonConvert.DeserializeObject<ReportsRequestOptions>(requestBody, new StringEnumJsonConverter<ReportType>());
    // StringEnum data is correct at this point
    if (!requestOptions.ReportTypes.Any())
        requestOptions.ReportTypes.AddRange(ReportType.All);

    var instanceId = await client.StartNewAsync(nameof(GetReports), requestOptions);

    return new OkObjectResult(instanceId);
}

[FunctionName(nameof(GetReports))]
public async Task<RunLog> GetReports(
    [OrchestrationTrigger] IDurableOrchestrationContext context
)
{
    var requestOptions = context.GetInput<ReportsRequestOptions>();
    // string enum data is correct at this point

    var clientReportsRequests = GetClientInfo(storeIds)
        .Select(x => new ClientReportsRequest()
        {
            ReportTypes = requestOptions.ReportTypes,
            Id = x.Id,
            From = requestOptions.From,
            To = requestOptions.To
        });

    // ParallelForEach Async code shouldn't be the issue here.
    // it's based on this article: https://dev.to/cgillum/scheduling-tons-of-orchestrator-functions-concurrently-in-c-1ih7
    var results = (await clientReportsRequests.ParallelForEachAsync(MaxParallelStoreThreadCount, clientReportsRequest =>
    {
        return context.CallSubOrchestratorAsync<(int, List<ReportRequest>)>(nameof(GetReportsForClient), clientReportsRequest);
    })).ToDictionary(x => x.Item1, x => x.Item2);
    
    return new RunLog(requestOptions, results);
}

[FunctionName(nameof(GetReportsForClient))]
public async Task<(int, List<ReportRequest>)> GetReportsForClient(
    [OrchestrationTrigger] IDurableOrchestrationContext context
)
{
    var requestOptions = context.GetInput<ClientReportsRequest>();

    var completedRequests = new List<ReportRequest>();
    foreach (var request in requestOptions.Requests)
    {
        completedRequests.add(GetReport(request));
        // GetReport code has been truncated for brevity but the issue is that neither field in the request
        // has it's StringEnum data at this point
    }

    return (requestOptions.Id, completedRequests);
}

这几天我一直在苦苦思索，找不到答案，有人有什么想法吗？有没有更好的方法来序列化它？

Answer 1

呃，这是 non-issue。我在 ClientReportsRequest 中遗漏了 public get on Requests 字段，很抱歉浪费了任何人的时间。

Azure Function Json 序列化问题

Azure Function Json Serialization issue

c#

azure-functions

azure-durable-functions

jsonconverter