tf_buffer_ = std::make_shared<tf2_ros::Buffer>

tf_buffer_ = std::make_shared<tf2_ros::Buffer> 是在使用tf2库时创建一个tf缓冲区的操作。这个缓冲区用于存储和查询tf变换关系，可以通过lookupTransform函数获取历史时间点的tf关系。 tf2_ros::Buffer是tf2库中的一个类，它提供了一个数据结构来存储tf变换关系，并且可以在需要时快速查询这些关系。<span class="em">1</span><span class="em">2</span><span class="em">3</span><span class="em">4</span>

相关问题

#include<iostream> #include<ctime> #include<chrono> #include<string> #include<filesystem> #include<fstream> #include<sstream> #include<thread> #include<boost/filesystem.hpp> const uintmax_t MAX_LOGS_SIZE = 10ull * 1024ull * 1024ull * 1024ull; //const uintmax_t MAX_LOGS_SIZE = 10ull; void create_folder(std::string folder_name) { boost::filesystem::create_directory(folder_name); std::string sub_foldername=folder_name+"/logs_ros"; boost::filesystem::create_directory(sub_foldername); } std::string get_current_time() { auto now = std::chrono::system_clock::now(); std::time_t now_c = std::chrono::system_clock::to_time_t(now); std::tm parts = *std::localtime(&now_c); char buffer[20]; std::strftime(buffer, sizeof(buffer), "%Y-%m-%d-%H-%M", &parts); return buffer; } void check_logs_size() { std::string logs_path = "/home/sage/logs/"; boost::filesystem::path logs_dir(logs_path); std::uintmax_t total_size = 0; for (const auto& file : boost::filesystem::recursive_directory_iterator(logs_dir)) { if (boost::filesystem::is_regular_file(file)) { total_size += boost::filesystem::file_size(file); } } if (total_size > MAX_LOGS_SIZE) { boost::filesystem::path earliest_dir; std::time_t earliest_time = std::time(nullptr); for (const auto& dir : boost::filesystem::directory_iterator(logs_dir)) { if (boost::filesystem::is_directory(dir)) { std::string dir_name = dir.path().filename().string(); std::tm time_parts = {}; std::istringstream ss(dir_name); std::string part; std::getline(ss, part, '-'); time_parts.tm_year = std::stoi(part) - 1900; std::getline(ss, part, '-'); time_parts.tm_mon = std::stoi(part) - 1; std::getline(ss, part, '-'); time_parts.tm_mday = std::stoi(part); std::getline(ss, part, '-'); time_parts.tm_hour = std::stoi(part); std::getline(ss, part, '-'); time_parts.tm_min = std::stoi(part); std::time_t dir_time = std::mktime(&time_parts); if (dir_time < earliest_time) { earliest_time = dir_time; earliest_dir = dir.path(); } } } if (!earliest_dir.empty()) { boost::filesystem::remove_all(earliest_dir); } } } int main() { std::string logs_path = "/home/sage/logs/"; while (true) { std::chrono::system_clock::time_point now = std::chrono::system_clock::now(); std::time_t now_c = std::chrono::system_clock::to_time_t(now); std::tm parts = *std::localtime(&now_c); if (parts.tm_min % 10 == 0) { std::string folder_name = logs_path + get_current_time(); create_folder(folder_name); } check_logs_size(); std::this_thread::sleep_for(std::chrono::minutes(1)); } return 0; }修改为ros节点

好的，我可以帮您将这段代码修改为ROS节点。首先，我们需要包含ROS所需的头文件，例如：

#include <ros/ros.h>

然后，我们需要在main函数中初始化ROS节点：

int main(int argc, char** argv) {
    ros::init(argc, argv, "log_manager_node");
    ros::NodeHandle nh;
    // ...
    return 0;
}

接下来，我们需要将定时任务和日志删除任务分别封装为ROS的定时器和服务。在main函数中，我们可以这样定义一个定时器：

ros::Timer timer = nh.createTimer(ros::Duration(60.0), timerCallback);

其中，`timerCallback` 是一个你需要定义的回调函数，它将在每隔60秒被定时器调用一次。在回调函数中，你可以像之前的代码一样执行创建文件夹和检查日志大小的任务。

同样地，我们可以定义一个ROS服务来执行删除任务。我们需要在main函数中定义一个服务服务器：

ros::ServiceServer delete_logs_server = nh.advertiseService("delete_logs", deleteLogsCallback);

其中，`deleteLogsCallback` 是一个你需要定义的服务回调函数，它将在收到删除日志服务请求时被调用。在回调函数中，你可以像之前的代码一样执行删除日志的任务。

最后，完整的ROS节点代码如下：

#include <ros/ros.h>
#include <ctime>
#include <chrono>
#include <string>
#include <filesystem>
#include <fstream>
#include <sstream>
#include <thread>
#include <boost/filesystem.hpp>

const uintmax_t MAX_LOGS_SIZE = 10ull * 1024ull * 1024ull * 1024ull;

void create_folder(std::string folder_name) {
    boost::filesystem::create_directory(folder_name);
    std::string sub_foldername = folder_name + "/logs_ros";
    boost::filesystem::create_directory(sub_foldername);
}

std::string get_current_time() {
    auto now = std::chrono::system_clock::now();
    std::time_t now_c = std::chrono::system_clock::to_time_t(now);
    std::tm parts = *std::localtime(&now_c);
    char buffer[20];
    std::strftime(buffer, sizeof(buffer), "%Y-%m-%d-%H-%M", &parts);
    return buffer;
}

void check_logs_size() {
    std::string logs_path = "/home/sage/logs/";
    boost::filesystem::path logs_dir(logs_path);
    std::uintmax_t total_size = 0;
    for (const auto& file : boost::filesystem::recursive_directory_iterator(logs_dir)) {
        if (boost::filesystem::is_regular_file(file)) {
            total_size += boost::filesystem::file_size(file);
        }
    }
    if (total_size > MAX_LOGS_SIZE) {
        boost::filesystem::path earliest_dir;
        std::time_t earliest_time = std::time(nullptr);
        for (const auto& dir : boost::filesystem::directory_iterator(logs_dir)) {
            if (boost::filesystem::is_directory(dir)) {
                std::string dir_name = dir.path().filename().string();
                std::tm time_parts = {};
                std::istringstream ss(dir_name);
                std::string part;
                std::getline(ss, part, '-');
                time_parts.tm_year = std::stoi(part) - 1900;
                std::getline(ss, part, '-');
                time_parts.tm_mon = std::stoi(part) - 1;
                std::getline(ss, part, '-');
                time_parts.tm_mday = std::stoi(part);
                std::getline(ss, part, '-');
                time_parts.tm_hour = std::stoi(part);
                std::getline(ss, part, '-');
                time_parts.tm_min = std::stoi(part);
                std::time_t dir_time = std::mktime(&time_parts);
                if (dir_time < earliest_time) {
                    earliest_time = dir_time;
                    earliest_dir = dir.path();
                }
            }
        }
        if (!earliest_dir.empty()) {
            boost::filesystem::remove_all(earliest_dir);
        }
    }
}

void timerCallback(const ros::TimerEvent& event) {
    std::string logs_path = "/home/sage/logs/";
    std::chrono::system_clock::time_point now = std::chrono::system_clock::now();
    std::time_t now_c = std::chrono::system_clock::to_time_t(now);
    std::tm parts = *std::localtime(&now_c);
    if (parts.tm_min % 10 == 0) {
        std::string folder_name = logs_path + get_current_time();
        create_folder(folder_name);
    }
    check_logs_size();
}

bool deleteLogsCallback(std_srvs::Empty::Request& req, std_srvs::Empty::Response& res) {
    std::string logs_path = "/home/sage/logs/";
    boost::filesystem::path logs_dir(logs_path);
    boost::filesystem::remove_all(logs_dir);
    return true;
}

int main(int argc, char** argv) {
    ros::init(argc, argv, "log_manager_node");
    ros::NodeHandle nh;

    ros::Timer timer = nh.createTimer(ros::Duration(60.0), timerCallback);
    ros::ServiceServer delete_logs_server = nh.advertiseService("delete_logs", deleteLogsCallback);

    ros::spin();
    return 0;
}

在这个节点中，我们定义了一个名为 `log_manager_node` 的ROS节点，并在其中实现了一个定时器和一个服务。定时器每隔60秒检查一次日志大小并创建新的日志文件夹，服务则用于删除所有日志文件。

/usr/bin/ld: CMakeFiles/global_planning_node.dir/src/global_planning_node.cpp.o: in function main.cold': global_planning_node.cpp:(.text.unlikely+0x273): undefined reference to tf::TransformListener::~TransformListener()' /usr/bin/ld: CMakeFiles/global_planning_node.dir/src/global_planning_node.cpp.o: in function main': global_planning_node.cpp:(.text.startup+0xc64): undefined reference to tf::Transformer::DEFAULT_CACHE_TIME' /usr/bin/ld: global_planning_node.cpp:(.text.startup+0xc92): undefined reference to tf::TransformListener::TransformListener(ros::Duration, bool)' /usr/bin/ld: global_planning_node.cpp:(.text.startup+0xd7a): undefined reference to tf::Transformer::lookupTransform(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::_cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, ros::Time const&, tf::StampedTransform&) const' /usr/bin/ld: global_planning_node.cpp:(.text.startup+0xe74): undefined reference to tf::TransformListener::~TransformListener()' collect2: error: ld returned 1 exit status make[2]: *** [CMakeFiles/global_planning_node.dir/build.make:246: /home/juan/catkin_ws/devel/.private/putn/lib/putn/global_planning_node] Error 1 make[1]: *** [CMakeFiles/Makefile2:207: CMakeFiles/global_planning_node.dir/all] Error 2 make[1]: *** Waiting for unfinished jobs.... /usr/bin/ld: CMakeFiles/local_obs_node.dir/src/local_obs.cpp.o: in function rcvVelodyneCallBack(sensor_msgs::PointCloud2<std::allocator<void> > const&)': local_obs.cpp:(.text+0xa0b): undefined reference to tf::Transformer::waitForTransform(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, ros::Time const&, ros::Duration const&, ros::Duration const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) const' /usr/bin/ld: local_obs.cpp:(.text+0xc74): undefined reference to tf::TransformListener::transformPoint(std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, geometry_msgs::PointStamped<std::allocator<void> > const&, geometry_msgs::PointStamped<std::allocator<void> >&) const' /usr/bin/ld: CMakeFiles/local_obs_node.dir/src/local_obs.cpp.o: in function main.cold': local_obs.cpp:(.text.unlikely+0x37d): undefined reference to tf::TransformListener::~TransformListener()' /usr/bin/ld: CMakeFiles/local_obs_node.dir/src/local_obs.cpp.o: in function main':local_obs.cpp:(.text.startup+0x62a): undefined reference to tf::Transformer::DEFAULT_CACHE_TIME' /usr/bin/ld: local_obs.cpp:(.text.startup+0x64d): undefined reference to tf::TransformListener::TransformListener(ros::Duration, bool)' /usr/bin/ld: local_obs.cpp:(.text.startup+0x6dc): undefined reference to tf::TransformListener::~TransformListener()' collect2: error: ld returned 1 exit status make[2]: *** [CMakeFiles/local_obs_node.dir/build.make:246: /home/juan/catkin_ws/devel/.private/putn/lib/putn/local_obs_node] Error 1 make[1]: *** [CMakeFiles/Makefile2:612: CMakeFiles/local_obs_node.dir/all] Error 2 make: *** [Makefile:141: all] Error 2解释编译时出现这个问题的原因，并说说如何解决

这个编译错误是因为链接器找不到tf库的符号引用。tf库是一个用于处理坐标变换的库，它提供了TransformListener和Transformer等类。

要解决这个问题，你需要确保tf库正确地链接到你的项目中。以下是一些可能的解决方法：

1. 确保tf库已经正确地安装在你的系统中。如果你使用的是ROS，可以通过运行以下命令来安装tf库：

   sudo apt-get install ros-<distro>-tf

这里的 `<distro>` 是你正在使用的ROS发行版，例如`melodic`或`noetic`。

2. 确保在你的CMakeLists.txt文件中正确地添加了tf库的依赖项。你可以在`find_package`命令后添加以下行来链接tf库：

   target_link_libraries(your_target_name ${catkin_LIBRARIES} tf)

这里的 `your_target_name` 是你的目标可执行文件的名称。

3. 如果你的项目使用了其他依赖项，例如tf2或tf2_ros，你可能还需要添加它们的链接库。例如：

   target_link_libraries(your_target_name ${catkin_LIBRARIES} tf tf2 tf2_ros)

4. 确保你的源代码文件中包含了正确的头文件引用。对于tf库，你可能需要包含`<tf/transform_listener.h>`和`<tf/transform_broadcaster.h>`。

尝试以上方法后，重新编译你的项目，应该能够解决链接错误。如果问题仍然存在，请确保在编译过程中没有其他错误或警告，并仔细检查你的代码和编译配置。