Remaining perf work for wolfictl text

[jonjohnsonjr]

Description

I'm going to stop digging into this, but I wanted to write down what I've found before dropping all context:

Once all the PRs I've sent are merged and those dependencies get bumped, wolfictl text ~400ms instead of ~250s (on my machine, at least).

What's left looks like this:

The biggest chunk in the middle is calling BuildFlavor, from here:
https://github.com/chainguard-dev/melange/blob/a3b7a002e874b75c318e5d2a2c3c7af7142f456c/pkg/build/pipeline.go#L97-L98

We end up Stating (I think) an empty directory a lot, so fixing that would shave off ~50ms.

There's also a ton of redundant reading of files and parsing of yamls and detecting of commits. I added some logging to see what's going on:

   7 loadUse.ReadFile("pipelines/cmake/install.yaml")
   8 loadUse.ReadFile("pipelines/cmake/build.yaml")
   8 loadUse.ReadFile("pipelines/cmake/configure.yaml")
  15 loadUse.ReadFile("pipelines/go/install.yaml")
  17 loadUse.ReadFile("pipelines/meson/configure.yaml")
  19 loadUse.ReadFile("pipelines/meson/compile.yaml")
  20 loadUse.ReadFile("pipelines/meson/install.yaml")
  31 loadUse.ReadFile("pipelines/ruby/clean.yaml")
  32 loadUse.ReadFile("pipelines/ruby/build.yaml")
  32 loadUse.ReadFile("pipelines/ruby/install.yaml")
  45 loadUse.ReadFile("pipelines/go/build.yaml")
 113 loadUse.ReadFile("pipelines/patch.yaml")
 166 loadUse.ReadFile("pipelines/autoconf/configure.yaml")
 185 loadUse.ReadFile("pipelines/git-checkout.yaml")
 253 loadUse.ReadFile("pipelines/autoconf/make-install.yaml")
 262 loadUse.ReadFile("pipelines/autoconf/make.yaml")
 495 loadUse.ReadFile("pipelines/strip.yaml")
 526 loadUse.ReadFile("pipelines/fetch.yaml")
 687 detectCommit(".")
4576 Stat("lib/libc.so.6")
4576 Stat("lib64/libc.so.6")

I'm a little hesitant to start refactoring things too much, but it seems like it would be straightforward to cache this stuff.

There are also a bunch of little things:

We spend a ton of time in https://github.com/chainguard-dev/go-apk/blob/2829525a71369b8c570b98332bb73639b1e59802/pkg/apk/version.go#L371 doing regex stuff. If it's possible to do this in a non-regexy way, we could save some time.

All of the string manipulation in here could also be a lot faster: https://gitlab.alpinelinux.org/alpine/go/-/blob/master/repository/repository.go

E.g. IndexUri(), NewRepositoryFromComponents, and Url should all be using path.Join instead of fmt.Sprintf.

The Packages() method should initialize pkgs with Count() capacity.

I suspect we could get this down to sub-100ms if we fix everything.