You are correct, the Marshaller won't be able to access the Context from the interceptor. Though not exactly for the reasons you mentioned. Unmarshalling happens prior to `ServerCall.Listener.onMessage` callback is executed:
1. io.grpc.MethodDescriptor.Marshaller unmarshaller the message --> 2. Contexts.interceptCall interceptor (ContextualizedServerCallListener <https://github.com/grpc/grpc-java/blob/f20c853c40ef620e79b01ebcec6fcf0f667cab61/api/src/main/java/io/grpc/Contexts.java#L63>) restores the contexts --> 3. ServerCall.Listener.onMessage callbacks are executed (with the context attached). To answer your question, could you please provide a bit more info on what you're trying to achieve? Why do you need microservice method name in the marshaller? There are a few possible approaches, but it really depends on your goals. Best Regards, Sergii On Monday, February 12, 2024 at 8:07:03 AM UTC-8 R Chinmay wrote: > I have a custom implementation of request marshaller (overriding > io.grpc.MethodDescriptor.Marshaller) > which I want to use, but I would need context information related to the > microservice call (specifically microservice method name being invoked). I > tried populating it in ServerInterceptor's interceptCall. My interceptor > code looks like this: > @Override > > public <ReqT, RespT> Listener<ReqT> interceptCall(ServerCall<ReqT, RespT> > serverCall, Metadata metadata, ServerCallHandler<ReqT, RespT> > serverCallHandler) { > > Context context = Context.current().withValue(MS_METHOD_NAME, > call.getMethodDescriptor().getFullMethodName()); > > return Contexts.interceptCall(context, serverCall, metadata, > serverCallHandler); > } > > But the context populated does not persist when unmarshalling of the > request stream takes place. > > This is because > io.grpc.internal.ServerImpl.ServerTransportListenerImpl#streamCreatedInternal > creates new > io.grpc.internal.ServerImpl.JumpToApplicationThreadServerStreamListener and > populates context using > io.grpc.internal.ServerImpl.ServerTransportListenerImpl#createContext which > just adds deadline and serverImpl instance fields over rootContext. So, the > information I populated was not available during unmarshalling. Also, > populating it in onMessage would not be useful too, since > io.grpc.internal.ServerCallImpl.ServerStreamListenerImpl#messagesAvailableInternal > > uses > listener.onMessage(call.method.parseRequest(message)); > > so parseRequest executes before onMessage is triggered. > > Is there some way to pass context information to marshaller, or maybe use > method name there. I am constructing methodDescriptor using > io.grpc.MethodDescriptor.Builder > -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/4baf2d88-de85-4bcd-a9d6-1bed0a20f2afn%40googlegroups.com.
