Client streaming operation

• response is optional
• input is a stream of data, represented by IAsyncEnumerable<> interface
• additional input parameters are optional
• context is optional
• the order of stream, input and context parameters does not matter

[OperationContract]
[Task<TResult>|Task] OperationName(IAsyncEnumerable<TData> stream, [T1 arg1, T2 arg2, ..., TN argN], [CancellationToken|CallContext context]);

[OperationContract]
[ValueTask<TResult>|ValueTask] OperationName(IAsyncEnumerable<TData> stream, [T1 arg1, T2 arg2, ..., TN argN], [CancellationToken|CallContext context]);

The gRPC protocol does not support input parameters. The only way to pass them to a server is by using HTTP request headers. In case the operation contains external input ([T1 arg1, T2 arg2, …, TN argN]), ServiceModel.Grpc framework will automatically:

• serialize them with the current IMarshallerFactory
• pass data in the binary request header

for example:

// standard gRPC client streaming call
[OperationContract]
Task<int> MultiplyBy2(IAsyncEnumerable<int> values);

// here multiplier value will be automatically passed in the binary request header
[OperationContract]
Task<int> MultiplyBy(IAsyncEnumerable<int> values, int multiplier);