Akka.Persistence.MongoDbReader

MongoReader.cs

public class AkkaMongoReader
{
    public ActorSystem Sys { get; }
    private readonly Akka.Serialization.Serialization _serialization;

    public AkkaMongoReader(ActorSystem sys)
    {
        Sys = sys;
        _serialization = Sys.Serialization;
    }

    public Persistent ToPersistenceRepresentation(JournalEntry entry)
    {
        int? serializerId = null;
        Type type = null;

        var legacy = entry.SerializerId.HasValue || !string.IsNullOrEmpty(entry.Manifest);
        if (!legacy)
        {
            var ser = _serialization.FindSerializerForType(typeof(Persistent));
            return ser.FromBinary<Persistent>((byte[])entry.Payload);
        }

        // legacy serialization
        if (!entry.SerializerId.HasValue && !string.IsNullOrEmpty(entry.Manifest))
            type = Type.GetType(entry.Manifest, true);
        else
            serializerId = entry.SerializerId;

        if (entry.Payload is byte[] bytes)
        {
            object deserialized = null;
            if (serializerId.HasValue)
            {
                deserialized = _serialization.Deserialize(bytes, serializerId.Value, entry.Manifest);
            }
            else
            {
                var deserializer = _serialization.FindSerializerForType(type);
                deserialized = deserializer.FromBinary(bytes, type);
            }

            if (deserialized is Persistent p)
                return p;

            return new Persistent(deserialized, entry.SequenceNr, entry.PersistenceId, entry.Manifest, entry.IsDeleted, ActorRefs.NoSender);
        }
        else // backwards compat for object serialization - Payload was already deserialized by BSON
        {
            return new Persistent(entry.Payload, entry.SequenceNr, entry.PersistenceId, entry.Manifest,
                entry.IsDeleted, ActorRefs.NoSender);
        }

    }
}