There’s a consensus that generally, c is very fast, and python is very slow. But if we are talking about go and rust, you would find that rust is slightly faster than go. So from fastest to slowest: c, rust, go, python.
But what if you have go, python and rust calling c function? There would be more overhead, but how much?
Calling C from Go, Python and Rust
Stats
Turns out python has the most overhead.
But with go and rust, overheads are more or less negligible, with rust having the least overhead.
Execution Time
You can see that python execution time plateaued, but go and rust are within the same range as c.
You would also notice that go and c have random execution time peaks, but rust is the most stable in terms of execution time. Additionally, calling the same c code, using rust results in the most constant memory usage footprint.
The Same Function But Implemented Natively
It’s the same pattern if native functions are used instead of c foreign function interface.
Calling C vs Native Function
But if we really have to compare CFFI and native function implementation, pure rust is faster than rust calling c
Side-by-side Comparison for Go and Rust
Comparing pure go (in blue) and go calling c, pure go execution time is faster.
With pure rust (in rust) and rust calling c it’s still native implementation faster than CFFI, although with rust, the overhead is more or less negligible.
But if we really have to compare c and pure rust (in rust), c is still faster, but the difference here is still negligible.
Bonus
You can also call rust from python via pyo3. In which, for the same function implementation, it is waaaaay faster than CFFI!
TLDR
- Calling c from go and rust doesn’t have much overhead. But if you are calling c from python, that’s a very different story.
- If we are talking about pure implementations, native rust is comparable to c.
- For boosting python performance, utilizing pyo3 via rust is also a good option, since it brings the performance closer to go and rust.