OpenDDS - 从单个 IDL 结构创建多个主题

在我的练习中OpenDDS我想从单个 IDL 结构创建多个主题，这可能吗？否则请让我知道该怎么做。

我是按照下面的方法做的，如果不对请指正。 我使用的示例可在OpenDDS-3.12/examples/DCPS/IntroductionToOpenDDS

IDL 如下：

StockQuoter.idl
---------------
module StockQuoter
{
#pragma DCPS_DATA_TYPE "StockQuoter::Quote"
#pragma DCPS_DATA_KEY "StockQuoter::Quote ticker"

  struct Quote {
    string ticker;
    string exchange;
    string full_name;
    double value;
    string data;
    TimeBase::TimeT timestamp;
  };
}

出版商.cpp

  // Create TOPICS and TYPES Vector
  std::stringstream ss;
  for(unsigned int idx = 0; idx < 100; ++idx)
  {
      ss << (idx+1);
      TOPICS.push_back("TOPIC" + std::string(ss.str()));
      TYPES.push_back("TYPE" + std::string(ss.str()));
      ss.clear();
      ss.str(std::string());
  }

     // Register
    for( unsigned int idx = 0; idx < 100; ++idx )
    {
        vec_quote_servent.push_back(new StockQuoter::QuoteTypeSupportImpl());
        if (DDS::RETCODE_OK != vec_quote_servent[idx]->register_type(participant.in (), TYPES[idx].c_str()))
        {
          cerr << "register_type for " << TYPES[idx] << " failed." << endl;
          ACE_OS::exit(1);
        }
    }

    // Create a topics
    for( unsigned int idx = 0; idx < 100; ++idx )
    {
         vec_quote_topic.push_back(   participant->create_topic (TOPICS[idx].c_str(),
                                      TYPES[idx].c_str(),
                                      default_topic_qos,
                                      DDS::TopicListener::_nil(),
                                      ::OpenDDS::DCPS::DEFAULT_STATUS_MASK));

         if (CORBA::is_nil (vec_quote_topic[idx].in ())) {
             cerr << "create_topic for " << TOPICS[idx] << " failed." << endl;
             ACE_OS::exit(1);
        }
     }

    // Create DataWriters
    for( unsigned int idx = 0; idx < 100; ++idx )
    {
         vec_quote_base_dw.push_back( pub->create_datawriter(vec_quote_topic[idx].in (),
                                      dw_default_qos,
                                      DDS::DataWriterListener::_nil(),
                                      ::OpenDDS::DCPS::DEFAULT_STATUS_MASK) );

        if (CORBA::is_nil (vec_quote_base_dw[idx].in ())) {
           cerr << "create_datawriter for " << TOPICS[idx] << " failed." << endl;
           ACE_OS::exit(1);
        }

        vec_quote_dw.push_back( StockQuoter::QuoteDataWriter::_narrow(vec_quote_base_dw[idx].in()) );
        if (CORBA::is_nil (vec_quote_dw[idx].in ())) {
          cerr << TOPICS[idx] << " could not be narrowed"<< endl;
          ACE_OS::exit(1);
        }
    }

    // Create handle
    for( unsigned int idx = 0; idx < 100 ; ++idx )
    {
        {
            StockQuoter::Quote topic2;
            topic2.ticker = CORBA::string_dup(TOPICS[idx].c_str());
            vec_topic_handle.push_back(vec_quote_dw[idx]->register_instance(topic2));
        }
    }

      // Publish data
      StockQuoter::Quote vec_quote;
      vec_quote.exchange = STOCK_EXCHANGE_NAME;
      vec_quote.ticker = CORBA::string_dup("VEC_TOPIC");
      vec_quote.full_name = CORBA::string_dup("TOPIC Receipts");
      vec_quote.value = 1600.0 + 10.0*i;
      vec_quote.timestamp = get_timestamp();

      for(unsigned int idx = 0; idx < 100; ++idx )
      {
          vec_quote.value += idx + 10;
          cout << "Publishing " << TOPICS[idx] << " : " << vec_quote.value <<endl;
          ret = vec_quote_dw[idx]->write(vec_quote, vec_topic_handle[idx]);
          if (ret != DDS::RETCODE_OK) {
             ACE_ERROR ((LM_ERROR, ACE_TEXT("(%P|%t) ERROR: TOPIC2 write returned %d.\n"), ret));
          }
      }

a，现在我明白你想问的问题了。您可以在每个主题的一个文件中或全部在一个文件中定义不同的主题类型。如果您在 IDL 文件中定义多个主题类型，则会为每个文件生成类型支持。让我用您使用的相同示例更准确地描述这一点。 IDL 文件为IntroductionToOpenDDS示例如下：

#include "orbsvcs/TimeBase.idl"

module StockQuoter
{
#pragma DCPS_DATA_TYPE "StockQuoter::Quote"
#pragma DCPS_DATA_KEY "StockQuoter::Quote ticker"

struct Quote {
    string ticker;
    string exchange;
    string full_name;
    double value;
    TimeBase::TimeT timestamp;
};

#pragma DCPS_DATA_TYPE "StockQuoter::ExchangeEvent"
#pragma DCPS_DATA_KEY "StockQuoter::ExchangeEvent exchange"

enum ExchangeEventType { TRADING_OPENED,
                       TRADING_CLOSED,
                       TRADING_SUSPENDED,
                       TRADING_RESUMED };
struct ExchangeEvent {
    string exchange;
    ExchangeEventType event;
    TimeBase::TimeT timestamp;
};
};

如您所见，定义了两种类型：Quote and ExchangeEvent。编译此 IDL 文件时，键入对两者的支持Quote and ExchangeEvent被生成。 您已经使用了使用此行的类型支持（QuoteTypeSupportImpl):

    vec_quote_servent.push_back(new StockQuoter::QuoteTypeSupportImpl());

生成相同类型的支持ExchangeEvent，你会发现一个名为的类型支持StockQuoter::ExchangeEvent with a StockQuoter::ExchangeEventTypeSupportImpl()方法。只需使用它来创建一个主题类型ExchangeEvent.

我希望这有帮助。如果需要更多详细信息，请随时询问。