bool PbToJsonConverter::Convert()

in src/json2pb/pb_to_json.cpp [70:177]

• 90 lines of code
• 27 McCabe index (conditional complexity)

bool PbToJsonConverter::Convert(const google::protobuf::Message& message, Handler& handler, bool root_msg) {
    const google::protobuf::Reflection* reflection = message.GetReflection();
    const google::protobuf::Descriptor* descriptor = message.GetDescriptor();

    int ext_range_count = descriptor->extension_range_count();
    int field_count = descriptor->field_count();
    std::vector<const google::protobuf::FieldDescriptor*> fields;
    fields.reserve(64);
    for (int i = 0; i < ext_range_count; ++i) {
        const google::protobuf::Descriptor::ExtensionRange*
            ext_range = descriptor->extension_range(i);
#if GOOGLE_PROTOBUF_VERSION < 4025000
        for (int tag_number = ext_range->start; tag_number < ext_range->end; ++tag_number)
#else
        for (int tag_number = ext_range->start_number(); tag_number < ext_range->end_number(); ++tag_number)
#endif
        {
            const google::protobuf::FieldDescriptor* field =
                    reflection->FindKnownExtensionByNumber(tag_number);
            if (field) {
                fields.push_back(field);
            }
        }
    }
    std::vector<const google::protobuf::FieldDescriptor*> map_fields;
    for (int i = 0; i < field_count; ++i) {
        const google::protobuf::FieldDescriptor* field = descriptor->field(i);
        if (_option.enable_protobuf_map && json2pb::IsProtobufMap(field)) {
            map_fields.push_back(field);
        } else {
            fields.push_back(field);
        }
    }

    if (root_msg && _option.single_repeated_to_array) {
        if (map_fields.empty() && fields.size() == 1 && fields.front()->is_repeated()) {
            return _PbFieldToJson(message, fields.front(), handler);
        }
    }

    handler.StartObject();

    // Fill in non-map fields
    std::string field_name_str;
    for (size_t i = 0; i < fields.size(); ++i) {
        const google::protobuf::FieldDescriptor* field = fields[i];
        if (!field->is_repeated() && !reflection->HasField(message, field)) {
            // Field that has not been set
            if (field->is_required()) {
                _error = "Missing required field: " + field->full_name();
                return false;
            }
            // Whether dumps default fields
            if (!_option.always_print_primitive_fields) {
                continue;
            }
        } else if (field->is_repeated()
                   && reflection->FieldSize(message, field) == 0
                   && !_option.jsonify_empty_array) {
            // Repeated field that has no entry
            continue;
        }

        const std::string& orig_name = field->name();
        bool decoded = decode_name(orig_name, field_name_str); 
        const std::string& name = decoded ? field_name_str : orig_name;
        handler.Key(name.data(), name.size(), false);
        if (!_PbFieldToJson(message, field, handler)) {
            return false;
        }
    }

    // Fill in map fields
    for (size_t i = 0; i < map_fields.size(); ++i) {
        const google::protobuf::FieldDescriptor* map_desc = map_fields[i];
        const google::protobuf::FieldDescriptor* key_desc =
                map_desc->message_type()->field(json2pb::KEY_INDEX);
        const google::protobuf::FieldDescriptor* value_desc =
                map_desc->message_type()->field(json2pb::VALUE_INDEX);

        // Write a json object corresponding to hold protobuf map
        // such as {"key": value, ...}
        const std::string& orig_name = map_desc->name();
        bool decoded = decode_name(orig_name, field_name_str);
        const std::string& name = decoded ? field_name_str : orig_name;
        handler.Key(name.data(), name.size(), false);
        handler.StartObject();
        std::string entry_name;
        for (int j = 0; j < reflection->FieldSize(message, map_desc); ++j) {
            const google::protobuf::Message& entry =
                    reflection->GetRepeatedMessage(message, map_desc, j);
            const google::protobuf::Reflection* entry_reflection = entry.GetReflection();
            entry_name = entry_reflection->GetStringReference(
                entry, key_desc, &entry_name);
            handler.Key(entry_name.data(), entry_name.size(), false);

            // Fill in entries into this json object
            if (!_PbFieldToJson(entry, value_desc, handler)) {
                return false;
            }
        }
        // Hack: Pass 0 as parameter since Writer doesn't care this
        handler.EndObject(0);
    }
    // Hack: Pass 0 as parameter since Writer doesn't care this
    handler.EndObject(0);
    return true;
}