Crafting Efficient Rust Code: A Step-by-Step Guide
As Rust developers, we strive to write code that is correct, readable, and performant. This trifecta of excellence is crucial for building fast, efficient, and maintainable software. In this tutorial, we’ll outline a sequence of steps to help you achieve CRaP (correct, readable, and performant) code for your next Rust project.
Why CRaP Code Matters
With the Rust compiler’s significant speedup and analysis passes becoming more powerful, developers can still complain about long compile times. Long compile times hinder productivity, and code readability is essential since code is read more often than written. Moreover, coding in a way that leaves room for future modifications pays back with interest. Finally, safety and soundness are paramount in Rust development.
Make It Work
When writing code, pay attention to variable naming and document your reasoning. Commenting your public interface early on, preferably with doc tests, ensures usability. Avoid making things generic until you have at least two use cases that require it. This approach rewards you with shorter compile times and easier maintenance.
Declare Your Data
Good data design leads to straightforward code. Avoid fancy algorithms initially, unless they’ll significantly improve performance. Keep track of allocations and make notes to fix them later. Reducing allocations can lead to quick wins.
Make It Right
Once your code works, it’s time to test it. Write doctests for all public methods, and consider using quickcheck or proptest for automatic test case generation. Use the type system to catch errors at compile time. Finally, review your code, looking for areas of improvement and performance pitfalls.
Make It Fast
If your program needs optimization, learn what needs optimizing first. Humans are poor at reasoning about where a program spends its time. Use sampling profilers, flamegraphs, and DHAT to identify hot spots. Look for algorithmic improvements, and then consider data layout optimization. If necessary, introduce concurrency, but be aware of Amdahl’s Law.
Know When to Stop
Optimizing code can be enjoyable, but it’s easy to get lost in it. Set clear performance goals and stop once you reach them. Remember that every optimization comes with increased complexity, reduced readability, and an expanded attack surface for bugs.
By following these steps, you’ll be well on your way to crafting efficient, readable, and correct Rust code. Happy coding!