roscpp: roscpp: subscriber.cpp Source File

00001 /*
00002  * Copyright (C) 2009, Willow Garage, Inc.
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions are met:
00006  *   * Redistributions of source code must retain the above copyright notice,
00007  *     this list of conditions and the following disclaimer.
00008  *   * Redistributions in binary form must reproduce the above copyright
00009  *     notice, this list of conditions and the following disclaimer in the
00010  *     documentation and/or other materials provided with the distribution.
00011  *   * Neither the names of Stanford University or Willow Garage, Inc. nor the names of its
00012  *     contributors may be used to endorse or promote products derived from
00013  *     this software without specific prior written permission.
00014  *
00015  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00016  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00017  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00018  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
00019  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
00020  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
00021  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00022  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00023  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
00024  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00025  * POSSIBILITY OF SUCH DAMAGE.
00026  */
00027 
00028 #include "ros/subscriber.h"
00029 #include "ros/node_handle.h"
00030 #include "ros/topic_manager.h"
00031 
00032 namespace ros
00033 {
00034 
00035   Subscriber::Impl::Impl()
00036   : unsubscribed_(false)
00037   { }
00038 
00039   Subscriber::Impl::~Impl()
00040   {
00041     ROS_DEBUG("Subscriber on '%s' deregistering callbacks.", topic_.c_str());
00042     unsubscribe();
00043   }
00044 
00045   bool Subscriber::Impl::isValid() const
00046   {
00047     return !unsubscribed_;
00048   }
00049 
00050   void Subscriber::Impl::unsubscribe()
00051   {
00052     if (!unsubscribed_)
00053       {
00054         unsubscribed_ = true;
00055         TopicManager::instance()->unsubscribe(topic_, helper_);
00056         node_handle_.reset();
00057         helper_.reset();
00058       }
00059   }
00060 
00061   Subscriber::Subscriber(const std::string& topic, const NodeHandle& node_handle, 
00062                          const SubscriptionCallbackHelperPtr& helper)
00063   : impl_(new Impl)
00064   {
00065     impl_->topic_ = topic;
00066     impl_->node_handle_ = NodeHandlePtr(new NodeHandle(node_handle));
00067     impl_->helper_ = helper;
00068   }
00069 
00070   Subscriber::Subscriber(const Subscriber& rhs)
00071   {
00072     impl_ = rhs.impl_;
00073   }
00074 
00075   Subscriber::~Subscriber()
00076   {
00077   }
00078 
00079   void Subscriber::shutdown()
00080   {
00081     if (impl_)
00082       {
00083         impl_->unsubscribe();
00084       }
00085   }
00086 
00087   std::string Subscriber::getTopic() const
00088   {
00089     if (impl_)
00090       {
00091         return impl_->topic_;
00092       }
00093 
00094     return std::string();
00095   }
00096 
00097   uint32_t Subscriber::getNumPublishers() const
00098   {
00099     if (impl_ && impl_->isValid())
00100       {
00101         return TopicManager::instance()->getNumPublishers(impl_->topic_);
00102       }
00103 
00104     return 0;
00105   }
00106 
00107 } // namespace ros