Endpoints support sending and receiving large chunks of data via the data bus.
It is possible to create a custom data bus implementation. This is done by making use of the Features extension.
As of NServiceBus 9.2, the DataBus feature is available as a dedicated NuGet package. The API documented on this page will continue to work for NServiceBus Version 9 but it will hint about its upcoming obsoletion with the following warning: The DataBus feature is released as a dedicated 'NServiceBus.ClaimCheck' package.. The new documentation is here.
Implement the IDataBus interface
This new class will provide the custom implementations for the Get and Put methods for the data bus.
class CustomDataBus :
IDataBus
{
public Task<Stream> Get(string key, CancellationToken cancellationToken)
{
Stream stream = File.OpenRead("blob.dat");
return Task.FromResult(stream);
}
public async Task<string> Put(Stream stream, TimeSpan timeToBeReceived, CancellationToken cancellationToken)
{
await using var destination = File.OpenWrite("blob.dat");
await stream.CopyToAsync(destination, 81920, cancellationToken);
return "the-key-of-the-stored-file-such-as-the-full-path";
}
public Task Start(CancellationToken cancellationToken)
{
return Task.CompletedTask;
}
}
This new implementation needs to be registered as a new feature.
Define a feature
Define a new feature that registers the custom data bus implementation class.
class CustomDatabusFeature : Feature
{
public CustomDatabusFeature()
=> DependsOn<DataBus>();
protected override void Setup(FeatureConfigurationContext context)
=> context.Services.AddSingleton<IDataBus, CustomDataBus>();
}
Define a DataBusDefinition
Define a new class which inherits from the DataBusDefinition class.
class CustomDatabusDefinition : DataBusDefinition
{
protected override Type ProvidedByFeature()
=> typeof(CustomDatabusFeature);
}
Configure the endpoint
Configure the endpoint to use the custom data bus implementation instead of the default data bus:
endpointConfiguration.UseDataBus(svc => new CustomDataBus(), new SystemJsonDataBusSerializer());