ArgumentOutOfRangeException in RssDictionarySample

[ttustonic]

Hello
I'm trying to run RssDictionarySample, but I get the ArgumentOutOfRangeException in line 49, when creating a new PersistentDictionary.

Unhandled Exception: System.TypeInitializationException: The type initializer for 'RssDictionarySample.TrivialRssReader' threw an exception. ---> System.ArgumentOutOfRangeException: Not supported for SetColumn Parameter name: TColumn Actual value was RssDictionarySample.RssFeedData.

it seems that ESENTCOLLECTIONS_SUPPORTS_SERIALIZATION is not defined, so how do I use a custom struct for a PersistentDictionary value?

[speed2048]

I am having the same issue, Is there any solution for this... I looked at the source code, to complicate for me to figure out why :)

[speed2048]

Okay I found out.... The following link explains why....

https://github.com/microsoft/ManagedEsent/releases

Would suggest to the owners of this repository to remove any examples that no longer work.... I am going to try and compile with ESENTCOLLECTIONS_SUPPORTS_SERIALIZATION defined to see how far I get..

[speed2048]

Forget using this if you want to to use .net core > 2.0. Found this that prevents its usage.

dotnet/runtime#23169

Darn all I want is a serializable Dictionary<int, T>. The two I have found don't work...

[ttustonic]

You can serialize your T objects to JSON and use as a string in Dictionary<int, string>.

[speed2048]

That what I am doing.... To bad ManagedEsent is not very useful now.

Thx...

[ttustonic]

Hm, I'm using it to hold a huge taxonomy database/dictionary and it works quite nice.
I serialize objects to Json string, convert to byte[] and use in a PersistentDictionary with PersistentBlob value.
PersistentDictionary<TKey, PersistentBlob> _dictionary

But, yes, it would be nice to remove samples that does not work, and create samples that do.

[speed2048]

I tried what you suggested but running into this issue. dotnet/runtime#23169.

It dies on this line of code..
var dictionary = new PersistentDictionary<int, PersistentBlob>("file-queue-2");

Any help would be appreciated...

[ttustonic]

Here's a working example. It creates a PersistentDictionary in the folder dest and every time you run the program it adds a new Test object and dumps previously added one.

    class Test
    {
            public int Id { get; set; }
            public string Name { get; set; }
    } 

    static async Task Main(string[] args)
    {
        var dic = new PersistentDictionary<int, PersistentBlob>("dest");

        int max = 0;
        if (dic.Keys.Count > 0)
            max = dic.Keys.Max();

        if (dic.TryGetValue(max, out var blob))
        {
            var bytes = blob.GetBytes();
            var str = Encoding.Default.GetString(bytes);
            var test = JsonSerializer.Deserialize<Test>(str);
            Console.WriteLine($"{test.Id} {test.Name}");
        }

        var newId = max + 1;
        var t1 = new Test { Id = newId, Name = "Name_" + newId.ToString() };
        var t1json = JsonSerializer.Serialize(t1);
        var t1bytes = Encoding.Default.GetBytes(t1json);
        var t1b = new PersistentBlob(t1bytes);
        dic.Add(newId, t1b); 

[speed2048]

Thank you for the example are you running this under .netframework netstandard2.0 or netcoreapp3.1? I am still getting the issue with your example..

[ttustonic]

It works in core 3.1 and .net 4.7.2 console apps.
Using nuget package Microsoft.Database.Collections.Generic ver 2.0.1
dic should be disposed at the end.

[speed2048]

That did it thank you... I had used my own compiled versions....