openidea/perf/compare/README.md

IDE comparison

pnpm perf measures OpenIDEA from inside its webview. This measures any IDE from the outside, the same way for each, so OpenIDEA can be compared with IntelliJ IDEA (or anything else listed in apps.toml).

pip install -r perf/compare/requirements.txt
python perf/compare/bench.py ~/src/spring-petclinic --runs 10
python perf/compare/bench.py ~/src/spring-petclinic --runs 5 --wipe-caches   # cold index

Each run launches the app on the project, waits until it is ready, idles, closes it, and records:

Metric	How
window_s	first visible window whose title matches window_title (the project name)
ready_s	the process tree's CPU stays under --quiet-cores for --quiet-secs, after the window and any ready_after markers
markers	first/last time a log line matches, e.g. OpenIDEA indexed, IDEA exit dumb mode
peak_rss_mb, rss_mb, uss_mb, pss_mb	summed over every process the app started (WebView2/WebKit, jdtls, language servers, the JVM)
total_cpu_s, idle_cpu_pct	CPU time until ready; CPU while idle for --idle-secs
exit_s	until every process has exited
cache_mb, install size	cache_dirs, install_dir

Apps run interleaved, rotating the order, after --warmup discarded runs. Output goes to results/<time>-<project>/: report.md (median, min–max), results.json, and each run's stdout.

Fair runs

• Release builds only; a running instance of the same executable (a pnpm tauri dev build too) would take over the launch, so the script refuses.
• IDEA: open the project once by hand and trust it; turn off Reopen projects on startup and Confirm before exiting; note the version, -Xmx and whether Shared Indexes were on.
• Same machine, power plan and plugged in; exclude the project and caches from antivirus scanning, or neither.
• --drop-os-cache runs a command before each launch for a cold OS cache: sync; echo 3 | sudo tee /proc/sys/vm/drop_caches (Linux), sudo purge (macOS), RAMMap64.exe -Et (Windows, admin).
• Typing latency is not covered: measure it on screen with Typometer for both.

Platform notes

• Windows: windows via user32, closed with WM_CLOSE.
• macOS: windows via Quartz (pyobjc-framework-Quartz; titles need Screen Recording permission). WebKit helpers are children of launchd and are attributed through responsibility_get_pid_responsible_for_pid.
• Linux: windows via wmctrl (X11). Without it window_s is skipped and readiness counts from launch.