Book Image

MySQL 5.1 Plugin Development

Book Image

MySQL 5.1 Plugin Development

Overview of this book

MySQL has introduced a Plugin API with its latest version – a robust, powerful, and easy way of extending the server functionality with loadable modules on the fly. But until now anyone wishing to develop a plugin would almost certainly need to dig into the MySQL source code and search the Web for missing bits of the information.This is the first book on the MySQL Plugin API. Written together with one of the Plugin API primary architects, it contains all the details you need to build a plugin. It shows what a plugin should contain and how to compile, install, and package it. Every chapter illustrates the material with thoroughly explained source code examples.Starting from the basic features, common to all plugin types, and the structure of the plugin framework, this book will guide you through the different plugin types, from simple examples to advanced ones. Server monitoring, full-text search in JPEG comments, typo-tolerant searches, getting the list of all user variables, system usage statistics, or a complete storage engine with indexes – these and other plugins are developed in different chapters of this book, demonstrating the power and versatility of the MySQL Plugin API and explaining the intricate details of MySQL Plugin programming.
Table of Contents (16 chapters)
MySQL 5.1 Plugin Development
About the Authors
About the Reviewer

A Hello World! Daemon plugin

Now, let's look at our first complete plugin example. This plugin is probably the most basic plugin we can have. It simply prints a message into the MySQL error log when loaded:

#include <stdio.h>
#include <mysql/plugin.h>
#include <mysql_version.h>

These are the basic includes required for most Daemon plugins. The most important being mysql/plugin.h, which contains macros and data structures necessary for a MySQL plugin.

static int hello_world_plugin_init(void *p)
fprintf(stderr, "Hello World: "
"This is a static text daemon example plugin!\n");
return 0;

In the plugin initialization function we simply write a message to stderr. MySQL redirects stderr to the error log (if there is one) so our message will end up there. We then return 0 to indicate that the initialization was successful.

struct st_mysql_daemon hello_world_info =

This structure is used for the info part of the plugin declaration. In Daemon...