Going Native With FFI - Euruko 2021

Ruby is a flexible language that allows us to write expressive and maintainable code. However, sometimes it could be necessary to work with a low-level language, looking for better performance. In this talk, I’m going to show you how to use Ruby to create an interface for compiled languages like C.

In this talk I’m going to talk about how ruby can work jointly with languages like C, creating a simple communication interface that allows us to use all the benefits of the low-level languages in our favorite high-level language.
Furthermore, I will present the alternatives that ruby provides to communicate our application with low-level libraries, and we will explore the pros and cons of these approaches.
Finally, we will analyze a practical case about how to create a ruby extension using ruby-ffi.

This talk is aimed at people interested in performance issues as well as interested in including libraries made in another language within their project without the need to migrate outside of Ruby.

The talk is designed for an intermediate-level audience, although the fundamental concepts are explained along with it, so a beginner could find it interesting

Transcript

1. GOING NATIVE WITH FFI Juan C. Ruiz
2. ❏ Sr. Full Stack developer @ EasyBroker ❏ Remote work advocate ❏ I ❤ Open source @JuanCrg90
3. @JuanCrg90 Heroes' Causeway Arch Leon Guanajuato Photo By @marianozka
4. @JuanCrg90
5. @JuanCrg90
6. What are the options we have to manage native code in Ruby? @JuanCrg90
7. MKMF @JuanCrg90
8. @JuanCrg90 mkmf.rb is used by Ruby C extensions to generate a Makefile which will correctly compile and link the C extension to Ruby and a third-party library.
9. library.h library.c @JuanCrg90
10. my_ruby_ext.c @JuanCrg90
11. extconf.rb @JuanCrg90
12. @JuanCrg90
13. @JuanCrg90 my_ruby_ext.rb
14. DEMO
15. Pros: - We can use C functions in our Ruby Code - We take advantage of the existing ruby.h library to create the extension Cons: - We need to add extra C code to create the bindings - This solution only works in MRI @JuanCrg90
16. FFI @JuanCrg90
17. A foreign function interface (FFI) is a mechanism by which a program written in one programming language can call routines or make use of services written in another. @JuanCrg90
18. @JuanCrg90
19. Pros: - We don’t need to add additional C code - An FFI extension is multi-platform and multi-implementation Cons: - Complex macros are difficult to maintain - Same for callback functions @JuanCrg90
20. PGM IMAGES @JuanCrg90
21. @JuanCrg90 feep.pgm
22. @JuanCrg90 pgm.h
23. @JuanCrg90 makefile
24. @JuanCrg90
25. @JuanCrg90 lib/pgm/bindings/base.rb
26. @JuanCrg90 lib/pgm/bindings/structs.rb
27. @JuanCrg90 C Struct Ruby Layout
28. @JuanCrg90 lib/pgm/functions.rb
29. @JuanCrg90
30. DEMO
31. @JuanCrg90
32. Conclusion @JuanCrg90
33. @JuanCrg90 https://github.com/JuanCrg90/pgm_ffi https://github.com/JuanCrg90/my_ruby_ext
34. THANKS @JuanCrg90 • Website: https://juancrg90.me/ • Twitter: @JuanCrg90 • Github: JuanCrg90