This PR builds on #780 by making both version parsing faster, and
perhaps more importantly, making version comparisons much faster.
Overall, these changes result in a considerable improvement for the
`boto3.in` workload. Here's the status quo:
```
$ time puffin pip-compile --no-build --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/requirements/boto3.in
Resolved 31 packages in 34.56s
real 34.579
user 34.004
sys 0.413
maxmem 2867 MB
faults 0
```
And now with this PR:
```
$ time puffin pip-compile --no-build --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/requirements/boto3.in
Resolved 31 packages in 9.20s
real 9.218
user 8.919
sys 0.165
maxmem 463 MB
faults 0
```
This particular workload gets stuck in pubgrub doing resolution, and
thus benefits mightily from a faster `Version::cmp` routine. With that
said, this change does also help a fair bit with "normal" runs:
```
$ hyperfine -w10 \
"puffin-base pip-compile --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/benchmarks/requirements.in" \
"puffin-cmparc pip-compile --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/benchmarks/requirements.in"
Benchmark 1: puffin-base pip-compile --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/benchmarks/requirements.in
Time (mean ± σ): 337.5 ms ± 3.9 ms [User: 310.5 ms, System: 73.2 ms]
Range (min … max): 333.6 ms … 343.4 ms 10 runs
Benchmark 2: puffin-cmparc pip-compile --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/benchmarks/requirements.in
Time (mean ± σ): 189.8 ms ± 3.0 ms [User: 168.1 ms, System: 78.4 ms]
Range (min … max): 185.0 ms … 196.2 ms 15 runs
Summary
puffin-cmparc pip-compile --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/benchmarks/requirements.in ran
1.78 ± 0.03 times faster than puffin-base pip-compile --cache-dir ~/astral/tmp/cache/ -o /dev/null ./scripts/benchmarks/requirements.in
```
There is perhaps some future work here (detailed in the commit
messages), but I suspect it would be more fruitful to explore ways of
making resolution itself and/or deserialization faster.
Fixes#373, Closes#396
This PR does a bit of refactoring to the pep440 crate, and in
particular around the erorr types. This PR is meant to be a precursor
to another PR that does some surgery (both in parsing and in `Version`
representation) that benefits somewhat from this refactoring.
As usual, please review commit-by-commit.
The high level goal here is to improve the tests for the version parser.
Namely, we now check not just that version strings parse successfully,
but that they parse to the expected result.
We also do a few other cleanups. Most notably, `Version` is now an
opaque type so that we can more easily change its representation going
forward.
Reviewing commit-by-commit is suggested. :-)
This PR copies over the `pep440-rs` crate at commit
`a8303b01ffef6fccfdce562a887f6b110d482ef3` with no modifications.
It won't pass CI, but modifications will intentionally be confined to
later PRs.
Andrew Gallant
Charlie Marsh