text: /*
   * Copyright (C) 2012-2015 Open Source Robotics Foundation
   *
   * 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
   *
   *     http://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.
   *
  */
  
  #ifdef _WIN32
    // Ensure that Winsock2.h is included before Windows.h, which can get
    // pulled in by anybody (e.g., Boost).
    #include <Winsock2.h>
  #endif
  
  #include <boost/bind.hpp>
  #include <boost/function.hpp>
  #include "gazebo/transport/TopicManager.hh"
  #include "gazebo/transport/ConnectionManager.hh"
  #include "gazebo/transport/PublicationTransport.hh"
  
  using namespace gazebo;
  using namespace transport;
  
  int PublicationTransport::counter = 0;
  
  /////////////////////////////////////////////////
  PublicationTransport::PublicationTransport(const std::string &_topic,
                                             const std::string &_msgType)
  : topic(_topic), msgType(_msgType)
  {
    this->id = counter++;
    TopicManager::Instance()->UpdatePublications(this->topic, this->msgType);
  }
  
  /////////////////////////////////////////////////
  PublicationTransport::~PublicationTransport()
  {
    if (this->connection)
    {
      msgs::Subscribe sub;
      sub.set_topic(this->topic);
      sub.set_msg_type(this->msgType);
      sub.set_host(this->connection->GetLocalAddress());
      sub.set_port(this->connection->GetLocalPort());
      ConnectionManager::Instance()->Unsubscribe(sub);
      this->connection->Cancel();
      this->connection.reset();
  
      ConnectionManager::Instance()->RemoveConnection(this->connection);
    }
    this->callback.clear();
  }
  
  /////////////////////////////////////////////////
  void PublicationTransport::Init(const ConnectionPtr &_conn, bool _latched)
  {
    this->connection = _conn;
    msgs::Subscribe sub;
    sub.set_topic(this->topic);
    sub.set_msg_type(this->msgType);
    sub.set_host(this->connection->GetLocalAddress());
    sub.set_port(this->connection->GetLocalPort());
    sub.set_latching(_latched);
  
    this->connection->EnqueueMsg(msgs::Package("sub", sub));
  
    // Put this in PublicationTransportPtr
    // Start reading messages from the remote publisher
    this->connection->AsyncRead(boost::bind(&PublicationTransport::OnPublish,
          this, _1));
  }
  
  
  /////////////////////////////////////////////////
  void PublicationTransport::AddCallback(
      const boost::function<void(const std::string &)> &cb_)
  {
    this->callback = cb_;
  }
  
  /////////////////////////////////////////////////
  void PublicationTransport::OnPublish(const std::string &_data)
  {
    if (this->connection && this->connection->IsOpen())
    {
      this->connection->AsyncRead(
          boost::bind(&PublicationTransport::OnPublish, this, _1));
  
      if (!_data.empty())
      {
        if (this->callback)
          (this->callback)(_data);
      }
    }
  }
  
  /////////////////////////////////////////////////
  const ConnectionPtr PublicationTransport::GetConnection() const
  {
    return this->connection;
  }
  
  /////////////////////////////////////////////////
  std::string PublicationTransport::GetTopic() const
  {
    return this->topic;
  }
  
  /////////////////////////////////////////////////
  std::string PublicationTransport::GetMsgType() const
  {
    return this->msgType;
  }
  
  /////////////////////////////////////////////////
  void PublicationTransport::Fini()
  {
    /// Cancel all async operatiopns.
    if (this->connection)
    {
      this->connection->Cancel();
      // this->connection.reset();
    }
  }
  