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
Credits
About the Authors
About the Reviewer
Preface

A Binary Logs Information Schema plugin


MySQL has quite a few SHOW commands, many of which have Information Schema equivalents. There are, however, exceptions to this. One of them is the SHOW BINARY LOGS command. For this plugin we will take the function from the MySQL server that implements SHOW BINARY LOGS and convert it to an Information Schema plugin. This will also demonstrate another aspect important to Information Schema plugins that deal with MySQL internals—the fact that they need to handle locking. With the user variables it was not an issue, because only the current connection can access its variable. But multiple threads can access binary logs simultaneously so we need to take appropriate precautions to make sure that it does not happen.

#define MYSQL_SERVER
#include <mysql_priv.h>
bool schema_table_store_record(THD *thd, TABLE *table);
ST_FIELD_INFO binary_logs_fields[] =
{
{"LOG_NAME", 255, MYSQL_TYPE_STRING, 0, 0, 0, 0},
{"FILE_SIZE", 20, MYSQL_TYPE_LONGLONG, 0, 0, 0...