protocol 測試

腦洞大開一下，想比較一下rosbag和protocol誰的存儲性能好一些。最後的結果是protocol小勝。

實驗環境是在ros下，有一個實驗用的bag，其中有發佈scan。 分別用rosbag和自己寫的ros節點，使用proto轉存激光雷達的數據。

最後rosbag記錄下的文件是157.9M  proto是154.0M。

下面是工程代碼

#include "ros/ros.h"
#include "std_msgs/Header.h"
#include "sensor_msgs/LaserScan.h"
#include <iostream>
#include <fstream>
#include <string>
#include "laser.pb.h"
using namespace std;

LaserScanBag laser_scan_bag;

void chatterCallback(const sensor_msgs::LaserScan& scan)
{
  //ROS_INFO("I heard: [%s]", msg->data.c_str());
  cout << scan.header.stamp.sec << "  " << scan.header.stamp.nsec << endl;
  LaserScan *laser_scan_ptr = laser_scan_bag.add_laserscan();

  laser_scan_ptr->set_angle_min(scan.angle_min);
  laser_scan_ptr->set_angle_max(scan.angle_max);
  laser_scan_ptr->set_angle_increment(scan.angle_increment);
  laser_scan_ptr->set_time_increment(scan.time_increment);
  laser_scan_ptr->set_scan_time(scan.scan_time);
  laser_scan_ptr->set_range_min(scan.range_min);
  laser_scan_ptr->set_range_max(scan.range_max);
  for(int i=0;i<scan.ranges.size();i++)
      laser_scan_ptr->add_range(scan.ranges[i]);

}



int main(int argc, char **argv)
{
  GOOGLE_PROTOBUF_VERIFY_VERSION;

  ros::init(argc, argv, "listener");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subscribe("scan", 1000, chatterCallback);


  fstream input("laser_bag", ios::in | ios::binary);
  if(!input)
  {
      cout << "create laser_bag" << endl;
  }
  else if(!laser_scan_bag.ParseFromIstream(&input))
  {
      cerr << "fail to open laser_bag!";
      return 1;
  }

  while(ros::ok())
  {
    ros::spinOnce();
  }
  cout << "start write file" << endl;
  fstream output("laser_bag", ios::out | ios::trunc | ios::binary);
     if (!laser_scan_bag.SerializeToOstream(&output)) {
       cerr << "Failed to write address book." << endl;
       return -1;
     }

  cout << "end write file" << endl;

  cout << "end program" << endl;

  google::protobuf::ShutdownProtobufLibrary();


  return 0;
}

這是cmakelists，重點是最後幾句話

cmake_minimum_required(VERSION 2.8.3)
project(proto_test)

## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
  roscpp
  sensor_msgs
  std_msgs
)

## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)


## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()

################################################
## Declare ROS messages, services and actions ##
################################################

## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
##   * add a build_depend tag for "message_generation"
##   * add a build_depend and a run_depend tag for each package in MSG_DEP_SET
##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
##     but can be declared for certainty nonetheless:
##     * add a run_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
##   * add "message_generation" and every package in MSG_DEP_SET to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * add "message_runtime" and every package in MSG_DEP_SET to
##     catkin_package(CATKIN_DEPENDS ...)
##   * uncomment the add_*_files sections below as needed
##     and list every .msg/.srv/.action file to be processed
##   * uncomment the generate_messages entry below
##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)

## Generate messages in the 'msg' folder
# add_message_files(
#   FILES
#   Message1.msg
#   Message2.msg
# )

## Generate services in the 'srv' folder
# add_service_files(
#   FILES
#   Service1.srv
#   Service2.srv
# )

## Generate actions in the 'action' folder
# add_action_files(
#   FILES
#   Action1.action
#   Action2.action
# )

## Generate added messages and services with any dependencies listed here
# generate_messages(
#   DEPENDENCIES
#   sensor_msgs#   std_msgs
# )

################################################
## Declare ROS dynamic reconfigure parameters ##
################################################

## To declare and build dynamic reconfigure parameters within this
## package, follow these steps:
## * In the file package.xml:
##   * add a build_depend and a run_depend tag for "dynamic_reconfigure"
## * In this file (CMakeLists.txt):
##   * add "dynamic_reconfigure" to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * uncomment the "generate_dynamic_reconfigure_options" section below
##     and list every .cfg file to be processed

## Generate dynamic reconfigure parameters in the 'cfg' folder
# generate_dynamic_reconfigure_options(
#   cfg/DynReconf1.cfg
#   cfg/DynReconf2.cfg
# )

###################################
## catkin specific configuration ##
###################################
## The catkin_package macro generates cmake config files for your package
## Declare things to be passed to dependent projects
## INCLUDE_DIRS: uncomment this if you package contains header files
## LIBRARIES: libraries you create in this project that dependent projects also need
## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
#  INCLUDE_DIRS include
#  LIBRARIES proto_test
#  CATKIN_DEPENDS protobuf roscpp sensor_msgs std_msgs
#  DEPENDS system_lib
)

###########
## Build ##
###########

## Specify additional locations of header files
## Your package locations should be listed before other locations
# include_directories(include)
include_directories(
  ${catkin_INCLUDE_DIRS}
)

## Declare a C++ library
# add_library(proto_test
#   src/${PROJECT_NAME}/proto_test.cpp
# )

## Add cmake target dependencies of the library
## as an example, code may need to be generated before libraries
## either from message generation or dynamic reconfigure
# add_dependencies(proto_test ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})

## Declare a C++ executable
# add_executable(proto_test_node src/proto_test_node.cpp)

## Add cmake target dependencies of the executable
## same as for the library above
# add_dependencies(proto_test_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})

## Specify libraries to link a library or executable target against
# target_link_libraries(proto_test_node
#   ${catkin_LIBRARIES}
# )

#############
## Install ##
#############

# all install targets should use catkin DESTINATION variables
# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html

## Mark executable scripts (Python etc.) for installation
## in contrast to setup.py, you can choose the destination
# install(PROGRAMS
#   scripts/my_python_script
#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )

## Mark executables and/or libraries for installation
# install(TARGETS proto_test proto_test_node
#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )

## Mark cpp header files for installation
# install(DIRECTORY include/${PROJECT_NAME}/
#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
#   FILES_MATCHING PATTERN "*.h"rosrun 
#   PATTERN ".svn" EXCLUDE
# )

## Mark other files for installation (e.g. launch and bag files, etc.)
# install(FILES
#   # myfile1
#   # myfile2
#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
# )

#############
## Testing ##
#############

## Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_proto_test.cpp)
# if(TARGET ${PROJECT_NAME}-test)
#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()

## Add folders to be run by python nosetests
# catkin_add_nosetests(test)
LINK_DIRECTORIES(/usr/lib/x86_64-linux-gnu)

add_executable(test_main src/test_main.cpp src/laser.pb.cc)
target_link_libraries(test_main ${catkin_LIBRARIES} -lprotobuf )

最後是.proto。稍稍修改了一下googl裏的數據格式，爲了和rosbag記錄下的相同（但是還是少記錄了一個header，所以有點不嚴謹，但是相比於每一幀激光的數據，header有和沒有差不多）

message LaserScan {

  optional float angle_min = 2;
  optional float angle_max = 3;
  optional float angle_increment = 4;
  optional float time_increment = 5;
  optional float scan_time = 6;
  optional float range_min = 7;
  optional float range_max = 8;

  repeated float range = 9  [packed = true];
  repeated float intensity = 10  [packed = true];
}

message LaserScanBag{
  repeated LaserScan laserscan = 1;
}