How to properly publish a frame of data?

edit

Hi, I tried to change the LeGO-LOAM input to Quanergy M8 lidar data. I created getdata.cpp to parse the lidar data and publish it to /Velodyne_points topic, and LeGO-LOAM will subscribe to /velodyne_points topic to get every frame of data. The following is an overview of the main function of getdata.cpp.

ros::init(argc, argv, "getLidarData");    
ROS_INFO("\033[1;32m---->\033[0m Get Lidar Data Started.");

ros::NodeHandle nh;   
pubLaserCloud = nh.advertise<sensor_msgs::PointCloud2> (pointCloudTopic, 1);    
ros::Rate loop_rate(10);     

while (ros::ok())
{
    if (decodeLidarData())
    {
        publishLidarData();
        decodeReset();
    }

    ros::spinOnce();        
    loop_rate.sleep();
}

I found two problems at run time after the build passed.

1. I found that the program would block at loop_rate.sleep();,why does loop_rate.sleep(); block all the time? Theoretically it would only sleep 0.1 seconds.
2. I shielded loop_rate.sleep(); and re-executed the program. LeGO-LOAM can receive the data from the /Velodyne_points topic and display it in rviz, but the effect is not a continuous image. It looks like the image of the latter frame is directly added to the image of the previous frame. No reset will occur after each frame is displayed, which leads to the increasing number of point clouds displayed. Eventually, rviz collapsed[rviz-1] process has died [pid 21771, exit code -9, cmd /opt/ros/kinetic/lib/rviz/rviz -d /home/charile/catkin_ws/src/LeGO-LOAM-JY/LeGO-LOAM/launch/test.rviz __name:=rviz __log:=/home/charile/.ros/log/978ae40c-daa9-11e9-98b3-00044bc52231/rviz-1.log]. log file: /home/charile/.ros/log/978ae40c-daa9-11e9-98b3-00044bc52231/rviz-1*.log.

Before that, I successfully ran lego-loam with velodyne VLP16 laser radar. Now I want to implement it with Quanergy M8 laser radar. I just want to modify its input data and display it, but I don't know what is wrong. Can someone help me. Thanks advance.