quick-runtime.cpp

// Copyright 2018-2023:
//   GobySoft, LLC (2013-)
//   Community contributors (see AUTHORS file)
// File authors:
//   Toby Schneider <toby@gobysoft.org>
//
//
// This file is part of the Dynamic Compact Control Language Library
// ("DCCL").
//
// DCCL is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// DCCL is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with DCCL.  If not, see <http://www.gnu.org/licenses/>.
#include "dccl.h"
#include <iostream>
#include <memory>
 
// Advanced version of quick.cpp that loads the .proto at runtime, instead of compile time
// compile with g++ dccl-runtime.cpp -std=c++11 -lprotobuf -ldccl -o dccl-runtime && ./dccl-runtime
 
// sets Reflection fields based on type of value
void _set_field_value(const google::protobuf::Reflection* refl,
                      const google::protobuf::FieldDescriptor* field_desc,
                      std::unique_ptr<google::protobuf::Message>& msg, double val)
{
    refl->SetDouble(msg.get(), field_desc, val);
}
 
void _set_field_value(const google::protobuf::Reflection* refl,
                      const google::protobuf::FieldDescriptor* field_desc,
                      std::unique_ptr<google::protobuf::Message>& msg, bool val)
{
    refl->SetBool(msg.get(), field_desc, val);
}
 
void _set_field_value(const google::protobuf::Reflection* refl,
                      const google::protobuf::FieldDescriptor* field_desc,
                      std::unique_ptr<google::protobuf::Message>& msg, int val)
{
    if (field_desc->cpp_type() == google::protobuf::FieldDescriptor::CPPTYPE_ENUM)
    {
        auto enum_desc = field_desc->enum_type();
        auto enum_val_desc = enum_desc->FindValueByNumber(val);
        if (enum_val_desc)
            refl->SetEnum(msg.get(), field_desc, enum_val_desc);
    }
}
 
// Look up a field by name and set its value
template <typename FieldType>
void set_field(std::unique_ptr<google::protobuf::Message>& msg, const char* field_name,
               FieldType val)
{
    // use protobuf Reflection to fill in message
    const google::protobuf::Reflection* refl = msg->GetReflection();
    const google::protobuf::Descriptor* desc = msg->GetDescriptor();
    const google::protobuf::FieldDescriptor* field_desc = desc->FindFieldByName(field_name);
    if (field_desc)
        _set_field_value(refl, field_desc, msg, val);
    else
        std::cerr << "Invalid field name: " << field_name << std::endl;
}
 
int main()
{
    // Allows runtime compilation of .proto files
    dccl::DynamicProtobufManager::enable_compilation();
    // uncomment for debugging
    // dccl::dlog.connect(dccl::logger::DEBUG1_PLUS, &std::cerr);
 
    // Add any -I for protoc
    dccl::DynamicProtobufManager::add_include_path(
        "/home/toby/share/examples/quickstart_navreport");
 
    // FileDescriptor = type introspection on .proto
    const google::protobuf::FileDescriptor* nav_report_file_desc =
        dccl::DynamicProtobufManager::load_from_proto_file("navreport.proto");
 
    if (!nav_report_file_desc)
    {
        std::cerr << "Failed to read in navreport.proto" << std::endl;
        exit(EXIT_FAILURE);
    }
 
    std::string encoded_bytes;
    dccl::Codec codec;
 
    // Descriptor = type introspection on the Message
    // we know there's only one Message in this .proto (index 0)
    const google::protobuf::Descriptor* nav_report_desc = nav_report_file_desc->message_type(0);
    codec.load(nav_report_desc);
 
    // SENDER
    {
        auto r_out = dccl::DynamicProtobufManager::new_protobuf_message<
            std::unique_ptr<google::protobuf::Message>>(nav_report_desc);
 
        set_field(r_out, "x", 450.0);
        set_field(r_out, "y", 550.0);
        set_field(r_out, "z", -100.0);
        const int AUV = 1;
        set_field(r_out, "veh_class", AUV);
        set_field(r_out, "battery_ok", true);
 
        codec.encode(&encoded_bytes, *r_out);
    }
    // send encoded_bytes across your link
 
    // RECEIVER
    {
        auto r_in = codec.decode<std::unique_ptr<google::protobuf::Message>>(encoded_bytes);
        std::cout << r_in->ShortDebugString() << std::endl;
    }
}