third_party.pigweed.src/pw_rpc/fake_channel_output.cc
Wyatt Hepler 5ba80646bf pw_rpc: Update protocol for server streams
Update the server-to-client RPC packet types so that the packet type
unambiguously indicates whether it is the first or last packet. This is
already the case for client-to-server RPC packet types.

- Have RESPONSE always be the last packet in the stream. For RPCs
  without a server stream, it includes a payload. Remove
  SERVER_STREAM_END.
- Introduce the SERVER_STREAM packet, to parallel the CLIENT_STREAM
  packet.
- Update the server and client code and tests. Test that old-style
  streaming RPCs still work correctly.
- Refactor the duplicate MessageOutput class into a FakeChannelOutput
  used by both Nanopb and raw RPCs.
- In C++, don't encode default-valued payload and status fields.

Change-Id: I218772dad6c2981dda5f032f298ea43ee5e08b4d
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/49822
Commit-Queue: Wyatt Hepler <hepler@google.com>
Pigweed-Auto-Submit: Wyatt Hepler <hepler@google.com>
Reviewed-by: Alexei Frolov <frolv@google.com>
2021-06-23 00:56:39 +00:00

63 lines
1.8 KiB
C++

// Copyright 2021 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.
#include "pw_rpc_private/fake_channel_output.h"
#include "pw_assert/check.h"
#include "pw_result/result.h"
#include "pw_rpc/internal/packet.h"
namespace pw::rpc::internal::test {
void FakeChannelOutput::clear() {
ClearResponses();
total_responses_ = 0;
last_status_ = Status::Unknown();
done_ = false;
}
Status FakeChannelOutput::SendAndReleaseBuffer(
std::span<const std::byte> buffer) {
PW_CHECK(!done_);
PW_CHECK_PTR_EQ(buffer.data(), packet_buffer_.data());
if (buffer.empty()) {
return OkStatus();
}
Result<Packet> result = Packet::FromBuffer(buffer);
PW_CHECK_OK(result.status());
last_status_ = result.value().status();
switch (result.value().type()) {
case PacketType::RESPONSE:
// Server streaming RPCs don't have a payload in their response packet.
if (!server_streaming_) {
ProcessResponse(result.value().payload());
}
done_ = true;
break;
case PacketType::SERVER_STREAM:
ProcessResponse(result.value().payload());
break;
default:
PW_CRASH("Unhandled PacketType %d",
static_cast<int>(result.value().type()));
}
return OkStatus();
}
} // namespace pw::rpc::internal::test