third_party/pigweed/repo/pw_rpc/nanopb/nanopb_method.cc

   1 // Copyright 2020 The Pigweed Authors
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
   4 // use this file except in compliance with the License. You may obtain a copy of
   5 // the License at
   6 //
   7 //     https://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  12 // License for the specific language governing permissions and limitations under
  13 // the License.
  14
  15 #include "pw_rpc/internal/nanopb_method.h"
  16
  17 #include "pb_decode.h"
  18 #include "pb_encode.h"
  19 #include "pw_log/log.h"
  20 #include "pw_rpc/internal/packet.h"
  21
  22 namespace pw::rpc::internal {
  23
  24 using std::byte;
  25
  26 void NanopbMethod::CallUnary(ServerCall& call,
  27                              const Packet& request,
  28                              void* request_struct,
  29                              void* response_struct) const {
  30   if (!DecodeRequest(call.channel(), request, request_struct)) {
  31     return;
  32   }
  33
  34   const Status status = function_.unary(call, request_struct, response_struct);
  35   SendResponse(call.channel(), request, response_struct, status);
  36 }
  37
  38 void NanopbMethod::CallServerStreaming(ServerCall& call,
  39                                        const Packet& request,
  40                                        void* request_struct) const {
  41   if (!DecodeRequest(call.channel(), request, request_struct)) {
  42     return;
  43   }
  44
  45   internal::BaseServerWriter server_writer(call);
  46   function_.server_streaming(call, request_struct, server_writer);
  47 }
  48
  49 bool NanopbMethod::DecodeRequest(Channel& channel,
  50                                  const Packet& request,
  51                                  void* proto_struct) const {
  52   if (serde_.DecodeRequest(proto_struct, request.payload())) {
  53     return true;
  54   }
  55
  56   PW_LOG_WARN("Failed to decode request payload from channel %u",
  57               unsigned(channel.id()));
  58   channel.Send(Packet::ServerError(request, Status::DataLoss()));
  59   return false;
  60 }
  61
  62 void NanopbMethod::SendResponse(Channel& channel,
  63                                 const Packet& request,
  64                                 const void* response_struct,
  65                                 Status status) const {
  66   Channel::OutputBuffer response_buffer = channel.AcquireBuffer();
  67   std::span payload_buffer = response_buffer.payload(request);
  68
  69   StatusWithSize encoded = EncodeResponse(response_struct, payload_buffer);
  70
  71   if (encoded.ok()) {
  72     Packet response = Packet::Response(request);
  73
  74     response.set_payload(payload_buffer.first(encoded.size()));
  75     response.set_status(status);
  76     if (channel.Send(response_buffer, response).ok()) {
  77       return;
  78     }
  79
  80     // Re-acquire the buffer to encode an error packet.
  81     response_buffer = channel.AcquireBuffer();
  82   }
  83
  84   PW_LOG_WARN("Failed to encode response packet for channel %u",
  85               unsigned(channel.id()));
  86   channel.Send(response_buffer,
  87                Packet::ServerError(request, Status::Internal()));
  88 }
  89
  90 }  // namespace pw::rpc::internal