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libmaestro/proto/pw.rpc.packet.proto

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+// Copied from pigweed RPC library with modifications.
+// - Changed package specification.
+// - Removed java-package option.
+//
+// Original copyright:
+//   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.packet;
+
+enum PacketType {
+  // To simplify identifying the origin of a packet, client-to-server packets
+  // use even numbers and server-to-client packets use odd numbers.
+
+  // Client-to-server packets
+
+  // The client invokes an RPC. Always the first packet.
+  REQUEST = 0;
+
+  // A message in a client stream. Always sent after a REQUEST and before a
+  // CLIENT_STREAM_END.
+  CLIENT_STREAM = 2;
+
+  // The client received a packet for an RPC it did not request.
+  CLIENT_ERROR = 4;
+
+  // Deprecated, do not use. Send a CLIENT_ERROR with status CANCELLED instead.
+  // TODO(b/234879973): Remove this packet type.
+  DEPRECATED_CANCEL = 6;
+
+  // A client stream has completed.
+  CLIENT_STREAM_END = 8;
+
+  // Server-to-client packets
+
+  // The RPC has finished.
+  RESPONSE = 1;
+
+  // Deprecated, do not use. Formerly was used as the last packet in a server
+  // stream.
+  // TODO(b/234879973): Remove this packet type.
+  DEPRECATED_SERVER_STREAM_END = 3;
+
+  // The server was unable to process a request.
+  SERVER_ERROR = 5;
+
+  // A message in a server stream.
+  SERVER_STREAM = 7;
+}
+
+message RpcPacket {
+  // The type of packet. Determines which other fields are used.
+  PacketType type = 1;
+
+  // Channel through which the packet is sent.
+  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;
+
+  // Unique identifier for the call that initiated this RPC. Optionally set by
+  // the client in the initial request and sent in all subsequent client
+  // packets; echoed by the server.
+  uint32 call_id = 7;
+}