time_cache.h

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/*
 * Copyright (c) 2008, Willow Garage, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Willow Garage, Inc. nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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#ifndef TF2_TIME_CACHE_H
#define TF2_TIME_CACHE_H
 
#include "transform_storage.h"
 
#include <deque>
 
#include <ros/message_forward.h>
#include <ros/time.h>
 
#include <boost/shared_ptr.hpp>
 
namespace geometry_msgs
{
ROS_DECLARE_MESSAGE(TransformStamped);
}
 
namespace tf2
{
 
typedef std::pair<ros::Time, CompactFrameID> P_TimeAndFrameID;
 
class TimeCacheInterface
{
public:
  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
 
  virtual bool insertData(const TransformStorage& new_data, std::string* error_str = 0)=0;
 
  virtual void clearList()=0;
 
  virtual CompactFrameID getParent(ros::Time time, std::string* error_str) = 0;
 
  virtual P_TimeAndFrameID getLatestTimeAndParent() = 0;
 
 
 
  virtual unsigned int getListLength()=0;
 
  virtual ros::Time getLatestTimestamp()=0;
 
  virtual ros::Time getOldestTimestamp()=0;
};
 
typedef boost::shared_ptr<TimeCacheInterface> TimeCacheInterfacePtr;
 
class TimeCache : public TimeCacheInterface
{
 public:
  static const int MIN_INTERPOLATION_DISTANCE = 5; 
  static const unsigned int MAX_LENGTH_LINKED_LIST = 1000000; 
  static const int64_t DEFAULT_MAX_STORAGE_TIME = 10ULL * 1000000000LL; 
 
  TimeCache(ros::Duration  max_storage_time = ros::Duration().fromNSec(DEFAULT_MAX_STORAGE_TIME));
 
 
 
  virtual bool getData(ros::Time time, TransformStorage & data_out, std::string* error_str = 0);
  virtual bool insertData(const TransformStorage& new_data, std::string* error_str = 0);
  virtual void clearList();
  virtual CompactFrameID getParent(ros::Time time, std::string* error_str);
  virtual P_TimeAndFrameID getLatestTimeAndParent();
 
  virtual unsigned int getListLength();
  virtual ros::Time getLatestTimestamp();
  virtual ros::Time getOldestTimestamp();
  
 
private:
  typedef std::deque<TransformStorage> L_TransformStorage;
  L_TransformStorage storage_;
 
  ros::Duration max_storage_time_;
 
 
  //Assumes storage is already locked for it
  inline uint8_t findClosest(TransformStorage*& one, TransformStorage*& two, ros::Time target_time, std::string* error_str);
 
  inline void interpolate(const TransformStorage& one, const TransformStorage& two, ros::Time time, TransformStorage& output);
 
 
  void pruneList();
 
 
 
};
 
class StaticCache : public TimeCacheInterface
{
 public:
 
  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
  virtual bool insertData(const TransformStorage& new_data, std::string* error_str = 0);
  virtual void clearList();
  virtual CompactFrameID getParent(ros::Time time, std::string* error_str);
  virtual P_TimeAndFrameID getLatestTimeAndParent();
 
 
  virtual unsigned int getListLength();
  virtual ros::Time getLatestTimestamp();
  virtual ros::Time getOldestTimestamp();
  
 
private:
  TransformStorage  storage_;
};
 
}
 
#endif // TF2_TIME_CACHE_H