2021-03-02 自定义插件my_plugin

MySQL源码中包含了插件开发的例子，在源码目录plugin/daemon_example，该例子实现的是每隔5秒向数据目录的mysql-heartbeat.log文件中写入心跳时间戳.以daemon_example为基础，开发自定义插件。

拷贝daemon_example目录改名为my_plugin，依次修改my_plugin目录下的文件，把daemon_example修改为my_plugin

image.png

#CMakeLists.txt
MYSQL_ADD_PLUGIN(my_plugin
        my_plugin.cc
  MODULE_ONLY
  MODULE_OUTPUT_NAME "libmy_plugin"
  TEST_ONLY
  )

INSTALL(FILES
        my_plugin.ini
  DESTINATION ${INSTALL_PLUGINDIR}
  COMPONENT Test
  )

#my_plugin.cc
  fn_format(heartbeat_filename, "my_plugin", "", ".log",
            MY_REPLACE_EXT | MY_UNPACK_FILENAME);

mysql_declare_plugin(daemon_example){
    MYSQL_DAEMON_PLUGIN,
    &daemon_example_plugin,
    "my_plugin",
    "jzh",
    "Daemon example, creates a heartbeat beat file in my_plugin.log",
    PLUGIN_LICENSE_GPL,
    daemon_example_plugin_init,   /* Plugin Init */
    NULL,                         /* Plugin Check uninstall */
    daemon_example_plugin_deinit, /* Plugin Deinit */
    0x0100 /* 1.0 */,
    NULL, /* status variables                */
    NULL, /* system variables                */
    NULL, /* config options                  */
    0,    /* flags                           */
} mysql_declare_plugin_end;

#my_plugin.ini
libmy_plugin
my_plugin

clion 编译插件生成 libdaemon_example.so 　并放到插件目录下　，授予可以执行权限

cp ./cmake-build-debug/plugin_output_directory/libdaemon_example.so /data1/mycode/mysql_debug/mysql-8.0.18/mysql_stuff/install/lib/plugin/

chown jzh:jzh /data1/mycode/mysql_debug/mysql-8.0.18/mysql_stuff/install/lib/plugin/libmy_plugin.so

安装

INSTALL PLUGIN my_plugin SONAME 'my_plugin.so';

卸载

UNINSTALL PLUGIN my_plugin;

查看

select * from mysql.plugin;