It seems that I'm getting OT on this thread. I've created a new one <https://groups.google.com/forum/#!topic/grpc-io/NGwmSMrOADM>.
On Saturday, June 6, 2020 at 2:53:05 AM UTC+8, Lidi Zheng wrote: > > Your observation is right that if an interceptor returns a generator > instead of a grpc.Call object, downstream applications will lose access to > initial_metadata, trailing_metadata, etc.. > > However, in the API reference [1], the streaming interceptors define the > return value as: > > > An object that is both a Call for the RPC and an iterator of > response values. Drawing response values from the returned Call-iterator > may raise RpcError indicating termination of the RPC with non-OK status. > > So, returning a generator without wrapping it as grpc.Call is not fully > supported. Given that, this support can be implementWe always welcome > contributors. > > [1] > https://grpc.github.io/grpc/python/grpc.html#grpc.StreamStreamClientInterceptor > > <https://grpc.github.io/grpc/python/grpc.html#grpc.StreamStreamClientInterceptor> > > On Fri, Jun 5, 2020 at 3:16 AM <[email protected] <javascript:>> wrote: > >> It doesn't work if an interceptor intercepts the responses. >> Considering there is such an interceptor: >> def wrapper(iterator): >> for entry in iterator: >> yield entry >> class MyInterceptor(grpc.StreamStreamClientInterceptor): >> def intercept_stream_stream(self, continuation, client_call_details, >> request_iterator): >> return wrapper(continuation(client_call_details, request_iterator)) >> Well I know I could delegate a method `initial_metadata` to the original >> iterator, but unfortunately, I've seen many interceptors written in the way >> above, causing that I couldn't retrieve the initial metadata from last >> interceptor. >> Any idea? >> >> 在 2016年4月6日星期三 UTC+8上午9:08:36，Nathaniel Manista写道： >>> >>> On Tue, Apr 5, 2016 at 9:58 AM, Tang Weiyu <[email protected]> wrote: >>> >>>> Definition of rpc: >>>> rpc telemetrySubscribe(SubscriptionRequest) returns (stream >>>> OpenConfigData) {} >>>> >>> >>> What's important here is that the RPC is response-streaming: it will >>> return zero, or one, or many more responses. >>> >>> How to get metadata from client side for streaming type of rpc call? >>>> >>>> On Mon, Apr 4, 2016 at 5:15 PM, Tang Weiyu <[email protected]> wrote: >>>> >>>>> Thanks Nathaniel, unfortunately the returned response don't have those >>>>> 2 methods, though I did get the returned response in the form of stream >>>>> Type defined in proto file RCP. >>>>> Anything missing here? >>>>> >>>>> for data,call in stub.Subscribe(sub_req, _TIMEOUT_SECONDS): >>>>> metadata = data.initial_metadata() >>>>> >>>> >>> Unpacking the iterator returned by your RPC invocation appears to be a >>> mistake here. I suspect that this should be something like: >>> >>> my_response_iterator = stub.Subscribe(sub_req, _TIMEOUT_SECONDS) >>> my_initial_metadata = my_response_iterator.initial_metadata() >>> for my_response in my_response_iterator: >>> <take some action for each response value> >>> my_terminal_metadata = my_response_iterator.terminal_metadata() >>> >>> Again, the critical part is that the RPC is response-streaming - the >>> code for a response-unary RPC would look very different. >>> -N >>> >> -- >> 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 [email protected] <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/grpc-io/e93d5c60-693c-4790-b107-8a851f42df9fo%40googlegroups.com >> >> <https://groups.google.com/d/msgid/grpc-io/e93d5c60-693c-4790-b107-8a851f42df9fo%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/cefd0dad-ae11-4441-8c19-0d51a909aaa9o%40googlegroups.com.
