Interface IRequestContextFeature

Namespace: IceRpc.Features

Assembly: IceRpc.dll

Represents a feature that holds a read-only dictionary of strings. This feature can be transmitted as a Context field with both ice and icerpc.

public interface IRequestContextFeature

Examples

The following code shows how to update the request context from an interceptor.

// An interceptor that adds an entry to the request context. Since IRequestContextFeature.Value is
// read-only, the pattern is to retrieve the existing entries as an ImmutableDictionary, add the new
// entry to produce a new ImmutableDictionary, then install a new feature wrapping the result.
_ = new Pipeline()
    .Use(next => new InlineInvoker((request, cancellationToken) =>
    {
        IRequestContextFeature? feature = request.Features.Get<IRequestContextFeature>();
        ImmutableDictionary<string, string> dictionary =
            feature?.Value.ToImmutableDictionary() ?? ImmutableDictionary<string, string>.Empty;
        dictionary = dictionary.Add("CorrelationId", Guid.NewGuid().ToString());
        request.Features = request.Features.With<IRequestContextFeature>(
            new RequestContextFeature(dictionary));
        return next.InvokeAsync(request, cancellationToken);
    }))
    .UseRequestContext();

Remarks

An interceptor that needs to add or remove context entries should build a new dictionary and install a new IRequestContextFeature.

Properties

Value

Gets the value of this feature.

IReadOnlyDictionary<string, string> Value { get; }

Property Value