Optimizations

[asterite]

A couple of optimizations.

I used this benchmark (I replaced the contents of "benchmark.cr" with this):

require "benchmark"
require "./lucky_router"

router = LuckyRouter::Matcher(Symbol).new

router.add("get", "/users", :index)
router.add("post", "/users", :create)
router.add("get", "/users/:id", :show)
router.add("delete", "/users/:id", :delete)
router.add("put", "/users/:id", :update)
router.add("get", "/users/:id/edit", :edit)
router.add("get", "/users/:id/new", :new)

Benchmark.ips do |x|
  x.report("router") do
    router.match!("post", "/users")
    router.match!("get", "/users/1")
    router.match!("delete", "/users/1")
    router.match!("put", "/users/1")
    router.match!("get", "/users/1/edit")
    router.match!("get", "/users/1/new")
  end
end

Output in master:

router 336.80k (  2.97µs) (± 7.73%)  3.12kB/op  fastest

Output in this PR:

router 489.51k (  2.04µs) (± 4.33%)  2.02kB/op  fastest

The second commit makes the code slightly longer or harder to understand, so feel free to ignore this PR or change it.

[jwoertink]

Wow! Thanks for this! 😄 It looks great to me 🥳

[asterite]

Do you think it's worth it for me to send a next PR with more optimizations? I was able to reach something like this:

router 712.03k (  1.40µs) (± 4.64%)  1.33kB/op  fastest

This is by using a StaticArray on the heap of some size (say, 64 elements). If the route to match has less than 64 segments we put their values there, avoiding an array allocation on every match. Then we turn that into a Slice and use that for matching. Otherwise, we can allocate a new array, but that should be rare (a path with more than 64 segments).

But maybe it's too low-level by then... do you have any idea how much the router's performance affects overall endpoint performance?

[jwoertink]

Yeah! I say let's do it. This router is actually used by actually used by SpiderGazelle too https://github.com/spider-gazelle/action-controller/blob/master/shard.yml#L12 so it not only benefits us, but it benefits them as well!

do you have any idea how much the router's performance affects overall endpoint performance?

It does help a ton, especially with larger apps adding more and more routes. The one part that can still affect it though is that once in Lucky, we still have some macro code to pick apart the routes https://github.com/luckyframework/lucky/blob/master/src/lucky/routable.cr#L193. But I guess optimizing that side is another story.