buffer.cpp
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00001 /*
00002  * Copyright (c) 2008, Willow Garage, Inc.
00003  * All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions are met:
00007  *
00008  *     * Redistributions of source code must retain the above copyright
00009  *       notice, this list of conditions and the following disclaimer.
00010  *     * Redistributions in binary form must reproduce the above copyright
00011  *       notice, this list of conditions and the following disclaimer in the
00012  *       documentation and/or other materials provided with the distribution.
00013  *     * Neither the name of the Willow Garage, Inc. nor the names of its
00014  *       contributors may be used to endorse or promote products derived from
00015  *       this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00018  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00020  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
00021  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
00022  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
00023  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00024  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00025  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
00026  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00027  * POSSIBILITY OF SUCH DAMAGE.
00028  */
00029 
00033 #include "tf2_ros/buffer.h"
00034 
00035 #include <ros/assert.h>
00036 #include <sstream>
00037 
00038 namespace tf2_ros
00039 {
00040 
00041 Buffer::Buffer(ros::Duration cache_time, bool debug) :
00042   BufferCore(cache_time)
00043 {
00044   if(debug && !ros::service::exists("~tf2_frames", false))
00045   {
00046     ros::NodeHandle n("~");
00047     frames_server_ = n.advertiseService("tf2_frames", &Buffer::getFrames, this);
00048   }
00049 }
00050 
00051 geometry_msgs::TransformStamped 
00052 Buffer::lookupTransform(const std::string& target_frame, const std::string& source_frame,
00053                         const ros::Time& time, const ros::Duration timeout) const
00054 {
00055   canTransform(target_frame, source_frame, time, timeout);
00056   return lookupTransform(target_frame, source_frame, time);
00057 }
00058 
00059 
00060 geometry_msgs::TransformStamped 
00061 Buffer::lookupTransform(const std::string& target_frame, const ros::Time& target_time,
00062                         const std::string& source_frame, const ros::Time& source_time,
00063                         const std::string& fixed_frame, const ros::Duration timeout) const
00064 {
00065   canTransform(target_frame, target_time, source_frame, source_time, fixed_frame, timeout);
00066   return lookupTransform(target_frame, target_time, source_frame, source_time, fixed_frame);
00067 }
00068 
00073 ros::Time now_fallback_to_wall()
00074 {
00075   try
00076   {
00077     return ros::Time::now();
00078   }
00079   catch (ros::TimeNotInitializedException ex)
00080   {
00081     ros::WallTime wt = ros::WallTime::now(); 
00082     return ros::Time(wt.sec, wt.nsec); 
00083   }
00084 }
00085 
00091 void sleep_fallback_to_wall(const ros::Duration& d)
00092 {
00093   try
00094   {
00095       d.sleep();
00096   }
00097   catch (ros::TimeNotInitializedException ex)
00098   {
00099     ros::WallDuration wd = ros::WallDuration(d.sec, d.nsec); 
00100     wd.sleep();
00101   }
00102 }
00103 
00104 void conditionally_append_timeout_info(std::string * errstr, const ros::Time& start_time,
00105                                        const ros::Duration& timeout)
00106 {
00107   if (errstr)
00108   {
00109     std::stringstream ss;
00110     ss << ". canTransform returned after "<< (now_fallback_to_wall() - start_time).toSec() \
00111        <<" timeout was " << timeout.toSec() << ".";
00112     (*errstr) += ss.str();
00113   }
00114 }
00115 
00116 bool
00117 Buffer::canTransform(const std::string& target_frame, const std::string& source_frame, 
00118                      const ros::Time& time, const ros::Duration timeout, std::string* errstr) const
00119 {
00120   // Clear the errstr before populating it if it's valid.
00121   if (errstr)
00122     {
00123       errstr->clear();
00124     }
00125 
00126   if (!checkAndErrorDedicatedThreadPresent(errstr))
00127     return false;
00128 
00129   // poll for transform if timeout is set
00130   ros::Time start_time = now_fallback_to_wall();
00131   while (now_fallback_to_wall() < start_time + timeout && 
00132          !canTransform(target_frame, source_frame, time) &&
00133          (now_fallback_to_wall()+ros::Duration(3.0) >= start_time) &&  //don't wait when we detect a bag loop
00134          (ros::ok() || !ros::isInitialized())) // Make sure we haven't been stopped (won't work for pytf)
00135     {
00136       sleep_fallback_to_wall(ros::Duration(0.01));
00137     }
00138   bool retval = canTransform(target_frame, source_frame, time, errstr);
00139   conditionally_append_timeout_info(errstr, start_time, timeout);
00140   return retval;
00141 }
00142 
00143     
00144 bool
00145 Buffer::canTransform(const std::string& target_frame, const ros::Time& target_time,
00146                      const std::string& source_frame, const ros::Time& source_time,
00147                      const std::string& fixed_frame, const ros::Duration timeout, std::string* errstr) const
00148 {
00149   // Clear the errstr before populating it if it's valid.
00150   if (errstr)
00151     {
00152       errstr->clear();
00153     }
00154 
00155   if (!checkAndErrorDedicatedThreadPresent(errstr))
00156     return false;
00157 
00158   // poll for transform if timeout is set
00159   ros::Time start_time = now_fallback_to_wall();
00160   while (now_fallback_to_wall() < start_time + timeout && 
00161          !canTransform(target_frame, target_time, source_frame, source_time, fixed_frame) &&
00162          (now_fallback_to_wall()+ros::Duration(3.0) >= start_time) &&  //don't wait when we detect a bag loop
00163          (ros::ok() || !ros::isInitialized())) // Make sure we haven't been stopped (won't work for pytf)
00164          {  
00165            sleep_fallback_to_wall(ros::Duration(0.01));
00166          }
00167   bool retval = canTransform(target_frame, target_time, source_frame, source_time, fixed_frame, errstr);
00168   conditionally_append_timeout_info(errstr, start_time, timeout);
00169   return retval; 
00170 }
00171 
00172 
00173 bool Buffer::getFrames(tf2_msgs::FrameGraph::Request& req, tf2_msgs::FrameGraph::Response& res) 
00174 {
00175   res.frame_yaml = allFramesAsYAML();
00176   return true;
00177 }
00178 
00179 
00180 
00181 bool Buffer::checkAndErrorDedicatedThreadPresent(std::string* error_str) const
00182 {
00183   if (isUsingDedicatedThread())
00184     return true;
00185   
00186 
00187 
00188   if (error_str)
00189     *error_str = tf2_ros::threading_error;
00190 
00191   ROS_ERROR("%s", tf2_ros::threading_error.c_str());
00192   return false;
00193 }
00194 
00195 
00196 
00197 }


tf2_ros
Author(s): Eitan Marder-Eppstein, Wim Meeussen
autogenerated on Thu Jan 4 2018 03:35:36