Help with custom record struct serialized in .Net6 doesn't deserializing just after upgrade .Net7

[thiagof0701]

Hi,

First at all, I am your fan! I use your libs about 4 years and you rock!!!

About 2 months ago I moved all our binary database (+200k objects) from MessagePack to MemoryPack+BrotliCompressor. My projects were targeting .Net6.

Everything was working as good as expected. Here is a sample that's working on production: https://nextdial.nyc3.digitaloceanspaces.com/20220701.db

Yesterday I updated the VS Studio, installed the .Net7 and upgraded the projects from .Net6 to .Net7. After that, I run a small local test and it worked as expected. So, I export publish it to a clean test VPS with Ubuntu 22.04.1 + .Net7, run again and got a "deserialization failure" (it deserialize all correct except the custom struct, letting it with a default value).

That is the model I have:

    [MemoryPackable]
    public partial record struct DateTimeParam
    {
        [MemoryPackConstructor]
        public DateTimeParam(DateTimeOffset dateTime, long timestamp, bool isItInSeconds)
        {
            this.DateTime = dateTime;
            this.Timestamp = timestamp;
            this.IsItInSeconds = isItInSeconds;
        }

        public DateTimeParam(long timestamp, bool sec = false)
        {
            this.DateTime = sec ? DateTimeOffset.FromUnixTimeSeconds(timestamp) : DateTimeOffset.FromUnixTimeMilliseconds(timestamp);
            this.Timestamp = timestamp;
            this.IsItInSeconds = sec;
        }

        public DateTimeParam(DateTimeOffset dt, bool sec = false)
        {
            this.IsItInSeconds = sec;
            this.Timestamp = sec ? dt.ToUnixTimeSeconds() : dt.ToUnixTimeMilliseconds();
            this.DateTime = dt;
        }

        public DateTimeOffset DateTime { get; }
        public long Timestamp { get; }
        public bool IsItInSeconds { get; }
    }

    [MemoryPackable]
    public partial record class PlaySession
    {
        public DateTimeParam BeginDt { get; set; }
        public DateTimeParam? EndingDt { get; set; }
        public ushort? Duration { get; set; }
        public double Lat { get; set; }
        public double Lng { get; set; }
        public string Country { get; set; }
        public string City { get; set; }
        public string Region { get; set; }
        public string UserAgent { get; set; }
        public string? Referer { get; set; }
        public string? PlayerName { get; set; }
        public string? DeviceName { get; set; }
        public string ListenerId { get; set; }
        public string Ip { get; set; }
        public string Mount { get; set; }
        public string Server { get; set; }
        public string IcecastId { get; set; }
        public string? TrackId { get; set; }
    }

    [MemoryPackable(GenerateType.Collection)]
    public partial class PlaySessionCollection : PooledList<PlaySession>
    {
        public PlaySessionCollection() { }
        public PlaySessionCollection(int capacity) : base(capacity) { }
        public PlaySessionCollection(ReadOnlySpan<PlaySession> list) : base(list) { }
        public PlaySessionCollection(IEnumerable<PlaySession> list) : base(list) { }
    }

The "PooledList" is this package

What could I try to do to solve this issue?

Best,
Thiago

[neuecc]

please show error details(message and stacktrace)

[thiagof0701]

No exception are throw, just a default value after deserialization only for BeginDt/EndingDt.

Maybe is some type of bug in compilation.

Is there anything should looking for to clean the build process?

[neuecc]

thanks, I've understood, DateTimeParam has different memory layout between .NET 6 and .NET 7.
I think it is a compiler or runtime change, but I did not expect it at all.
I will look for the cause, please wait a moment.

[neuecc]

Although it is disucussioned in this Issue
dotnet/runtime#44579
.NET 6, it was forced to be promoted to LayoutKind.Auto, but since .NET 7, it seems to be Sequential.

as the workaround, .NET 6 and .NET 7 to the same memory layout by specifying LayoutKind.Auto.

[MemoryPackable]
[StructLayout(LayoutKind.Auto)]
public partial record struct DateTimeParam
{
}

Also, in the case of netstandard 2.1 code-generator, I will add this new analyzing feature,
if the unmanaged struct field contains an auto struct (such as DateTime or DateTimeOffset), code-generator displays the error that LayoutKind.Auto must be specified.

[thiagof0701]

It worked like a charm!

Tks for the reply and congrats for the best work you've been doing for so many years.