Dart analyzer performance drops drastically with analyzer plugin enabled

[khoadng]

Description:
After enabling the new analyzer plugin system, dart analyze runtime increases significantly on a fairly large monorepo ( ~150k lines of code, ~2100 Dart files and a dozen internal packages)

Macbook Pro M1: 6 seconds -> 42 seconds
Macbook Pro M4: 4 seconds -> 25 seconds

Remove the plugin from analysis_options.yaml bring the performance back to normal

Repo / branch for reproduction:
https://github.com/khoadng/Boorusama/tree/analyzer-plugin-profile
In this branch, the plugin only registers a single no-op rule.

Expected behavior:
Analyzer performance should remain close to baseline when adding a no-op or minimal plugin.

Environment:

• FVM to manage Dart/Flutter SDK versions
• Dart SDK: 3.10.0-285.0.dev
• analysis_server_plugin: ^0.3.1
• analyzer: ^8.2.0

[bwilkerson]

@srawlins

[srawlins]

Thanks for filing an issue, and thanks for the repro!

There are a few known overhead steps that will be ~fixed, regardless of the workspace size (writing a stub shared-entrypoint package, running dart pub get, compiling the code as an AOT snapshot, and then starting-up the AOT snapshot. But it's great you have a repro here with ~150k lines of code.

[srawlins]

I can reproduce, but my numbers aren't as bad as yours; on an M3 Max, I see 4s w/o plugins, and ~15s w/ plugins.

I suspect the best bang for our buck we can get is to avoid generating the AOT snapshot if possible, using timestamps.

[srawlins]

I added some logging and have found that on my machine (again, with the jump from 4s to ~15s), running dart pub upgrade in the generated shared plugin entrypoint takes 0.4s, and then compiling that shared entrypoint as a Dart AOT snapshot takes 9.6s.

So, given this example, the drastic increase in time-to-analyze is entirely attributable to the AOT compilation, which we should be able to cache.