tf2: tf2: time_cache.h Source File

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 
00032 #ifndef TF2_TIME_CACHE_H
00033 #define TF2_TIME_CACHE_H
00034 
00035 #include "transform_storage.h"
00036 
00037 #include <list>
00038 
00039 #include <sstream>
00040 
00041 #include <ros/message_forward.h>
00042 #include <ros/time.h>
00043 
00044 namespace geometry_msgs
00045 {
00046 ROS_DECLARE_MESSAGE(TransformStamped);
00047 }
00048 
00049 namespace tf2
00050 {
00051 
00052 typedef std::pair<ros::Time, CompactFrameID> P_TimeAndFrameID;
00053 
00054 class TimeCacheInterface
00055 {
00056 public:
00058   virtual bool getData(ros::Time time, TransformStorage & data_out, std::string* error_str = 0)=0; //returns false if data unavailable (should be thrown as lookup exception
00059 
00061   virtual bool insertData(const TransformStorage& new_data)=0;
00062 
00064   virtual void clearList()=0;
00065 
00067   virtual CompactFrameID getParent(ros::Time time, std::string* error_str) = 0;
00068 
00072   virtual P_TimeAndFrameID getLatestTimeAndParent() = 0;
00073 
00074 
00076 
00077   virtual unsigned int getListLength()=0;
00078 
00080   virtual ros::Time getLatestTimestamp()=0;
00081 
00083   virtual ros::Time getOldestTimestamp()=0;
00084 };
00085 
00086 
00091 class TimeCache : public TimeCacheInterface
00092 {
00093  public:
00094   static const int MIN_INTERPOLATION_DISTANCE = 5; 
00095   static const unsigned int MAX_LENGTH_LINKED_LIST = 1000000; 
00096   static const int64_t DEFAULT_MAX_STORAGE_TIME = 1ULL * 1000000000LL; 
00097 
00098   TimeCache(ros::Duration  max_storage_time = ros::Duration().fromNSec(DEFAULT_MAX_STORAGE_TIME));
00099 
00100 
00102 
00103   virtual bool getData(ros::Time time, TransformStorage & data_out, std::string* error_str = 0);
00104   virtual bool insertData(const TransformStorage& new_data);
00105   virtual void clearList();
00106   virtual CompactFrameID getParent(ros::Time time, std::string* error_str);
00107   virtual P_TimeAndFrameID getLatestTimeAndParent();
00108 
00110   virtual unsigned int getListLength();
00111   virtual ros::Time getLatestTimestamp();
00112   virtual ros::Time getOldestTimestamp();
00113   
00114 
00115 private:
00116   typedef std::list<TransformStorage> L_TransformStorage;
00117   L_TransformStorage storage_;
00118 
00119   ros::Duration max_storage_time_;
00120 
00121 
00123   //Assumes storage is already locked for it
00124   inline uint8_t findClosest(TransformStorage*& one, TransformStorage*& two, ros::Time target_time, std::string* error_str);
00125 
00126   inline void interpolate(const TransformStorage& one, const TransformStorage& two, ros::Time time, TransformStorage& output);
00127 
00128 
00129   void pruneList();
00130 
00131 
00132 
00133 };
00134 
00135 class StaticCache : public TimeCacheInterface
00136 {
00137  public:
00139 
00140   virtual bool getData(ros::Time time, TransformStorage & data_out, std::string* error_str = 0); //returns false if data unavailable (should be thrown as lookup exception
00141   virtual bool insertData(const TransformStorage& new_data);
00142   virtual void clearList();
00143   virtual CompactFrameID getParent(ros::Time time, std::string* error_str);
00144   virtual P_TimeAndFrameID getLatestTimeAndParent();
00145 
00146 
00148   virtual unsigned int getListLength();
00149   virtual ros::Time getLatestTimestamp();
00150   virtual ros::Time getOldestTimestamp();
00151   
00152 
00153 private:
00154   TransformStorage  storage_;
00155 };
00156 
00157 }
00158 
00159 #endif // TF2_TIME_CACHE_H