我正在尝试做类似下面的事情(即使用流式grpc调用从客户端向服务器发送数据).代码参考取自官方网站上给出的grpc示例,用于解释目的:
客户端代码:
ClientContext context; context.AddMetadata("authorization","abcd"); context.set_deadline(...); std::unique_ptr<ClientWriter<RequestObjectClass>> writer(stub_->grpcCall(&context,&response)); writer->WaitForInitialMetadata(); // Setting request parameters request.set...(...); request.set...(...); request.set...(...); request.set...(...); if (!writer->Write(request)) { Status status = writer->Finish(); if (status.error_code() == UNAUTHENTICATED) { std::cout << "UNAUTHORIZED" << std::endl; break; } // Broken stream. throw Exception("Broken Stream"); } writer->WritesDone(); Status status = writer->Finish(); if (status.ok()) { std::cout << "RPC succeeded." << std::endl; } else { std::cout << "RPC failed." << std::endl; }
服务器端代码:
std::multimap<grpc::string_ref,grpc::string_ref> metadata = context->client_metadata(); auto auth = metadata.find("authorization"); if (auth == metadata.end()) { return Status(StatusCode::UNAUTHENTICATED,"UNAUTHORIZED"); }
我得到“Broken stream”异常,因为Status的代码为“DEADLINE_EXCEEDED”,详细信息为“Deadline Exceeded”. ClientContext的截止时间超时是system_clock :: now()5秒.我究竟做错了什么?
解决方法
我刚刚删除了这一行“writer-> WaitForInitialMetadata();”它开始工作了.我认为这一行使客户端等待来自服务器的一些元数据.不过不确定.