The utility should support all the arguments supported by GNU cmp and
perform slightly better.
On a "bad" scenario, ~36M files which are completely different, our
version runs in ~72% of the time of the original on my M1 Max:
> hyperfine --warmup 1 -i --output=pipe \
'cmp -l huge huge.3'
Benchmark 1: cmp -l huge huge.3
Time (mean ± σ): 3.237 s ± 0.014 s [User: 2.891 s, System: 0.341 s]
Range (min … max): 3.221 s … 3.271 s 10 runs
Warning: Ignoring non-zero exit code.
> hyperfine --warmup 1 -i --output=pipe \
'../target/release/diffutils cmp -l huge huge.3'
Benchmark 1: ../target/release/diffutils cmp -l huge huge.3
Time (mean ± σ): 2.392 s ± 0.009 s [User: 1.978 s, System: 0.406 s]
Range (min … max): 2.378 s … 2.406 s 10 runs
Warning: Ignoring non-zero exit code.
Our cmp runs in ~116% of the time when comparing libxul.so to the
chromium-browser binary with -l and -b. In a best case scenario of
comparing 2 files which are the same except for the last byte, our
tool is slightly faster.
This is in preparation for adding the other diffutils commands, cmp,
diff3, sdiff.
We use a similar strategy to uutils/coreutils, with the single binary
acting as one of the supported tools if called through a symlink with
the appropriate name. When using the multi-tool binary directly, the
utility needds to be the first parameter.
* Implement -q/--brief option
* Optimization: stop analyzing the files as soon as there are any differences
* Unit tests for the stop_early parameter
* Simplify checks
Sylvestre Ledru
Olivier Tilloy
Gustavo Noronha Silva
Tanmay Patil