The full-text parser plugin architecture
Full-text parsers were the first plugin type implemented in the Plugin API. In fact, both the Plugin API and the full-text parsers were developed at the same time within the same project. Unlike Information Schema tables or storage engines, MySQL did not support multiple full-text parsers originally. The support for them was added together with the full-text parser plugins. No wonder the full-text parser API was carefully designed specifically for plugins, and it managed to achieve almost a complete separation of a plugin from the server internals. As a result, the full-text parser API is simple and very stable; it has hardly changed since its inception in 2005, and full-text parser plugin binaries that worked back then can still be loaded in MySQL now and they will work as designed.
Three roles of a full-text parser plugin
When MySQL needs to parse a piece of text, be it for insertion into a full-text index, deletion from a full-text index, or during...