Idle and streaming cost both depend on how much of the sidebar is mounted, so
the scenario setup is now shared. --expand-projects seeds the persisted collapse
state; --expand-sessions clicks every "Show more sessions" control, which
cannot be seeded because pagination is component state. Both run before the
measured window, so it stays input-free. Session expansion must run after the
sidebar has populated, not straight after the load event, or the controls do
not exist yet.
Also replaces a spread push over collected trace events, which overflowed the
call stack once a populated sidebar produced chunks of hundreds of thousands of
events, and the equivalent spread in the heap-maximum calculation.
Expanding a project with more worktrees and sessions than MAX_DIR_STORES put
the sidebar into an endless request loop (#1472).
Every sidebar row calls ensureChild during render, but the pin that protects
the directory is only taken in an effect after commit. ensureChild marked the
directory and ran eviction synchronously, so directories that were actively
rendering looked unpinned and were disposed. The next render recreated them
with a loading status, which issued another bootstrap request, and the cycle
repeated for as long as the project stayed expanded.
Raising the limit only moves the cliff, so the limit is now a soft target
instead: a directory touched within a grace window is never an overflow
victim. A burst of live directories overflows the cache briefly rather than
thrashing, while idle-time eviction still bounds it. Eviction is also coalesced
into one deferred pass per tick, so a render that mounts many rows no longer
sorts and scans every directory once per row, and a whole commit's pin effects
settle before anything is considered for disposal. Releasing the final consumer
stays synchronous, since that is an explicit lifecycle edge.
The idle profiler gains --expand-projects to reach this state.
Not yet verified end to end: reproducing the loop needs many worktrees under
one project, which this development environment does not have.
Adds `bun run profile:session`: creates a session, opens it in a real
browser, dispatches a prompt through the supported `openchamber session` CLI,
and records until the session reports itself idle. No input is synthesised, so
everything captured is the app reacting to its own event stream.
Streaming is judged by responsiveness rather than totals, so the report leads
with the long-task distribution, style recalculation and layout rates, frame
production, and the application's own stream counters.
Two failure modes are detected rather than reported as clean results. A session
belonging to a directory the browser is not viewing renders nothing and
produces a perfectly quiet profile, so the run verifies both new message
elements in the DOM and message-list render counters. And `RunTask` is only
emitted under the disabled-by-default timeline category, so a capture without
it reports zero long tasks; the missing-task case is now called out instead of
being shown as zero.
Metric helpers are shared with the idle profiler.
Idle cost depends on which surfaces are mounted, so the profiler needs to
reach those states without a human driving the UI.
`--panel <mode>` opens the context panel by seeding the persisted store the
app reads on boot, using the same tab identity rules as `useUIStore`.
`--then-tab <name>` navigates through the router after settling, which leaves
already-mounted surfaces mounted and measures what a screen keeps doing once
the user has moved on. Both drive real application state instead of
synthesising clicks, so the recorded window stays free of input-driven work.
Adds `bun run profile:idle`: a fully unattended capture of what OpenChamber
does while nobody interacts with it. It reports main-thread busy time, style
recalculation and layout rates, DOM node and listener growth, heap trajectory,
a CPU sampling profile, and per-call-site attribution of timer, animation
frame, and observer work.
Chrome throttles timers and stops producing frames for occluded or backgrounded
windows, which silently reports an idle-looking renderer regardless of what the
page schedules. Launch flags now disable that throttling, and every run measures
frame liveness so a throttled capture is reported as a warning rather than as a
clean result.
CDP launch and client code is shared with the existing browser profiler.
Bohdan Triapitsyn