// Copyright 2020 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
syntax = "proto3";

package pw.rpc.internal;

enum PacketType {
  // RPC packets correspond with a request or response for a service method.
  RPC = 0;

  // STREAM_END packets signal the end of a server or client stream.
  STREAM_END = 1;

  // CANCEL packets request termination of an ongoing RPC.
  CANCEL = 2;

  // ERROR packets are sent by the server to indicate that it received an
  // unexpected or malformed packet.
  ERROR = 3;
}

message RpcPacket {
  // The type of packet. Determines which other fields are used. Required.
  PacketType type = 1;

  // Channel through which the packet is sent. Required.
  uint32 channel_id = 2;

  // Hash of the fully-qualified name of the service with which this packet is
  // associated. For RPC packets, this is the service that processes the packet.
  fixed32 service_id = 3;

  // Hash of the name of the method which should process this packet.
  fixed32 method_id = 4;

  // The packet's payload, which is an encoded protobuf.
  bytes payload = 5;

  // Status code for the RPC response or error.
  uint32 status = 6;
}