Add benchmarks

[cleancut]

Add benchmarks

[CleanCut]

... which leads to this philosophical question: what is the selling point of headtail?

For me, it is purely the ability to be able to head AND tail in a simultaneous operation.

I'm not opposed to attempting to optimize performance as a secondary goal, but I sincerely doubt many people will ever be searching for a combined head and tail utility because either head or tail is too slow.

Actually, I see performance as more of a tertiary goal, with other useful features being the secondary goal (like following a file while tailing -- which I didn't actually need, but was fun to do).

[tbmreza]

As a utility whose name begs to be used alongside if not replace head and tail, I think the "benchmark" that's more anticipated in our introduction would be how does it fare against the OG coreutils counterparts.

For example, as a reader I want to know how

headtail somebigfile.txt

compares (after rigorous experiments) against

head somebigfile.txt && tail somebigfile.txt

Or headtail somebigfile.txt -H 25 -T 0 against head somebigfile.txt -n 25?

(Unless I misunderstood "when we make changes we can do a before/after comparison. See criterion.", which to me sounds like using the micro-benchmarking tool to do regression testing.)

[CleanCut]

Those all sound good to me!

[tbmreza]

Those all sound good to me!

Awesome. Working on it! 🤓

[tbmreza]

I found about hyperfine while researching about how such benchmarking could be done. https://github.com/uutils/coreutils/blob/main/src/uu/head/BENCHMARKING.md

There are a couple of options that we could do imo.

• Reference that link and/or add "Benchmarking" section to our readme
• Compile a table of numbers (a la https://github.com/BurntSushi/ripgrep#quick-examples-comparing-tools)

====

This is what hyperfine outputs for me:

hyperfine --warmup 3 "head tests/files/input.txt && tail tests/files/input.txt" "target/release/headtail tests/files/input.txt"
Benchmark 1: head tests/files/input.txt && tail tests/files/input.txt
  Time (mean ± σ):       5.4 ms ±   0.8 ms    [User: 2.0 ms, System: 1.8 ms]
  Range (min … max):     4.9 ms …   8.8 ms    263 runs

Benchmark 2: target/release/headtail tests/files/input.txt
  Time (mean ± σ):       7.3 ms ±   0.9 ms    [User: 4.7 ms, System: 1.8 ms]
  Range (min … max):     6.6 ms …  10.9 ms    280 runs

Summary
  'head tests/files/input.txt && tail tests/files/input.txt' ran
    1.34 ± 0.25 times faster than 'target/release/headtail tests/files/input.txt'

... which leads to this philosophical question: what is the selling point of headtail? Is being at least as fast as GNU coreutils counterparts a non-goal? What do you think? @CleanCut

[tbmreza]

In any case, that meaning of benchmark should be a separate github issue (if regarded valid at all). My next pull-request will be adding criterion for before/after change comparison ✌️.