Reduce background Git ref and port polling

[Quicksaver]

Summary

Reduce persistent background work from Git ref enumeration and preview port discovery while preserving freshness when users interact with either surface.

What Changed

• Revalidate only the first Git-ref page every 20 seconds instead of polling every retained page every five seconds
• Load cursor pages once per connected generation and expire inactive ref atoms after 30 seconds
• Refresh local and remote refs immediately when the composer branch or Diff comparison menu opens
• Replay the latest preview-discovery snapshot instead of running a duplicate subscription scan
• Serialize snapshot replay with concurrent broadcasts so subscribers cannot regress to stale results
• Scan immediately when managed terminal process sets change and ignore unchanged registrations or redundant removals
• Run the broad port-discovery safety net every 20 seconds while idle and every 10 seconds when a listener is known

Why

During extended use, T3 Code's resident memory climbed past 6 GB even while idle, while the renderer sustained roughly 10% CPU and the machine became noticeably warm around the CPU and GPU clusters. That pattern indicated that background work was continuing without user interaction and could compound renderer and resource pressure over long sessions.

Diagnostics identified two repeatable sources of idle churn: every retained Git-ref query, including each loaded pagination page, owned its own five-second listRefs revalidation loop, while preview discovery launched a broad lsof scan every three seconds. Preview subscription initialization could also scan twice, and unchanged terminal process registrations caused redundant probes. The new schedules reduce that steady subprocess load while immediate menu refreshes, terminal-process-triggered scans, and adaptive safety-net polling preserve freshness at interaction time.

Validation

• Port scanner focused suite passed with 6 tests, including concurrent replay ordering
• Targeted server and client-runtime type checks passed
• Isolated authenticated web verification loaded local, worktree, and remote refs when the branch selector opened
• git diff --check passed

Proof

No standalone proof artifacts were captured; the isolated browser verification is summarized above.

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Note

Medium Risk
Touches live preview discovery and ref freshness semantics across client and server; behavior is well tested but stale refs could linger up to 20s unless the user opens a menu.

Overview
Cuts idle background work from Git ref lists and preview port discovery while keeping data fresh when users open branch or comparison menus.

Git refs (client-runtime): First-page ref revalidation moves from 5s to 20s; paginated cursor pages no longer tick on an interval (one-shot per connection generation). Ref list atoms use a 30s idle TTL instead of five minutes. Tests assert the new 20s interval.

UI: refreshVcsRefsOnMenuOpen centralizes open-only ref refresh for the composer branch selector and Diff base-ref combobox (Diff refreshes local and remote); closing menus only clears search query, not refs.

Port discovery (server): Replaces a fixed 3s lsof poll with 20s idle / 10s when a listener is already known. Subscribers get the latest snapshot under a semaphore (no duplicate scan in ws.ts); terminal PID updates scan immediately but skip no-op re-registrations. New PortScanner tests cover replay, ordering, and deduped registrations.

^{Reviewed by Cursor Bugbot for commit bb1446c. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Reduce background Git ref and port polling frequency

• Increases the VCS ref revalidation interval from 5s to 20s and reduces the idle cache TTL to 30s; only the first page of refs is periodically revalidated while paginated pages are one-shot.
• Replaces the fixed 3s PortDiscovery poll interval with adaptive intervals: 10s when listeners are active and servers are known, 20s otherwise.
• New subscribers to PortDiscovery now receive an immediate replay of the latest snapshot instead of requiring an explicit scan in the WS handler.
• Adds a notificationLock semaphore to serialize snapshot broadcasts with subscription replays, preventing stale interleaving.
• Extracts refreshVcsRefsOnMenuOpen to centralize open-only ref refresh behavior across BranchToolbarBranchSelector and DiffPanel; closing a menu no longer triggers a refresh.

^{Macroscope summarized bb1446c.}

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[macroscopeapp]

Approvability

Verdict: Approved

Performance optimization that reduces polling intervals for Git refs and port scanning, with optimizations to avoid redundant work. Changes are well-tested, clearly documented, and limited to timing adjustments without introducing new features or behavioral complexity.

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[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

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^{Reviewed by Cursor Bugbot for commit bb1446c. Configure here.}

[cursor]

Leaked listener breaks port broadcasts

Medium Severity

PortDiscovery.subscribe adds the listener to scanner state and then replays the snapshot in the same acquire step. If that replay effect fails, Effect.acquireRelease skips release, so the listener stays registered even though the subscription never completed. Later broadcast runs every listener with Effect.forEach, so one failing replay listener can abort the whole broadcast and stop live port updates for other subscribers.

 

^{Reviewed by Cursor Bugbot for commit bb1446c. Configure here.}