* fix(tui-clipboard): skip native safety net on OSC52-capable terminals
On terminals with first-class OSC 52 support (Ghostty, kitty, WezTerm,
Windows Terminal, VS Code), setClipboard() currently fires both OSC 52
AND a parallel native-tool write (wl-copy / xclip / pbcopy). On Wayland
+ wl-copy this corrupts the clipboard: probeLinuxCopy() runs wl-copy
with empty stdin as an existence check (destructive — wipes clipboard
to empty string), and the subsequent real wl-copy invocation races
OSC 52 plus its own daemon's previous SIGTERM.
Symptom: user on Arch + Ghostty + wl-copy (Wayland, no tmux, no SSH)
had to press Ctrl+Shift+C three times before a selection landed.
env -u WAYLAND_DISPLAY -u DISPLAY HERMES_TUI_FORCE_OSC52=1 (which
short-circuits copyNative via the DISPLAY-absent early-return) made
every copy work instantly — proving OSC 52 alone is sufficient on
Ghostty and that copyNative() is actively destructive there.
Add OSC52_CAPABLE_TERMINALS allowlist to terminal.ts (same pattern as
the existing EXTENDED_KEYS_TERMINALS), and gate copyNative() on the
terminal NOT being on it. The native safety net continues to fire on
unrecognised terminals (xterm, GNOME Terminal, Konsole, Terminal.app,
etc.) where OSC 52 is less reliable.
* fix(tui-clipboard): address Copilot review feedback
- Move OSC52_CAPABLE_TERMINALS + supportsOsc52Clipboard() from
ink/terminal.ts to utils/env.ts. ink/terminal.ts already imports
link from ink/termio/osc.ts; importing back into termio/osc.ts
introduced a circular dependency. utils/env.ts has no deps on
either file and already owns terminal detection (detectTerminal()),
so the helper sits naturally next to it.
- Replace the inline gating (!SSH_CONNECTION && !supportsOsc52Clipboard())
with a pure shouldUseNativeClipboard(env, terminal) helper. The old
expression skipped native on allowlisted terminals even when
setClipboard() wouldn't actually emit OSC 52 (e.g. inside
TMUX/STY where we use tmux load-buffer instead, or when the user
has set HERMES_TUI_FORCE_OSC52=0). That made the clipboard write
a no-op in those configurations. The new helper:
1. SSH_CONNECTION set -> false (existing behaviour)
2. TMUX or STY set -> true (we go through load-buffer, no race)
3. shouldEmitClipboardSequence() false -> true (native is the
only path left when OSC 52 is suppressed)
4. Otherwise: skip native iff terminal is allowlisted.
- Add 11 tests for shouldUseNativeClipboard covering the SSH guard,
TMUX/STY tmux-inside-Ghostty case, HERMES_TUI_FORCE_OSC52=0
override, allowlisted vs non-allowlisted terminals, precedence,
and default-args smoke. Tests follow the package's existing
parameterised-helper style (no vi.mock; helpers accept env and
terminal as arguments).
- Update test imports to the new utils/env.js path.
* fix(tui-clipboard): address Copilot round 2 feedback
* fix(tui-clipboard): address Copilot round 3 feedback
* fix(tui-clipboard): address Copilot round 4 feedback
Adds an `evictInkCaches(level)` API that prunes the four hot module-level
caches (`widthCache`, `wrapCache`, `sliceCache`, `lineWidthCache`) with
either a half-keep LRU pass or a full clear. Wired into:
- memoryMonitor: half-prune on 'high', full drop on 'critical', before
the heap dump / auto-restart path. Gives long sessions a shot at
recovering RSS instead of hard-exiting.
- useSessionLifecycle.resetSession: half-prune so a /new session starts
with a half-warm pool and the prior session can resume cheaply.
Also: lineWidthCache now uses LRU half-eviction on overflow instead of a
full `cache.clear()`, matching the other three caches.
Comparison vs claude-code: both forks now share the same `prevScreen`
blit + dirty-cascade machinery in render-node-to-output. Their smoothness
came from sibling-memo discipline (every chrome pane memo'd so dirty
cascade doesn't disable transcript blit) — already in place in our
appLayout.tsx (TranscriptPane / ComposerPane / StatusRulePane all memo'd).
Alt-screen is not the cause; both use it. The remaining gap was per-row
CPU on width/wrap/slice, which the previous commit closed.
CPU profile (Apr 2026, real-user scroll on 11k-line session) showed three
hot loops in the per-frame render path:
Output.get() per-frame walk: 24% total
└─ sliceAnsi(line, from, to) per write: 18% total
stringWidth(line) chain (cached + JS): 14% total
All three were re-doing identical work every frame: same string → same
clipped slice → same width.
Fixes:
1. Memoize stringWidth (8k-entry LRU) for non-ASCII strings; ASCII fast-path
skips the cache (inline scan beats Map.get for short ASCII, the >90%
case). String.charCodeAt scan up to 64 chars is cheaper than the regex
fallback.
2. Memoize wrapText (4k-entry LRU keyed by maxWidth|wrapType|text) — wrapAnsi
is pure and the same content reflows identically every frame.
3. Memoize sliceAnsi (4k-entry LRU keyed by start|end|str) for the
end-defined hot path used by Output.get().
4. Skip the slice entirely in Output.get() when the line already fits the
clip box (startsBefore=false && endsAfter=false). Most transcript lines
never exceed their container width, and tokenizing them just to slice
(line, 0, width) was pure overhead. This single fast-path drops
sliceAnsi from 18% → ~0% in the profile.
Also tighten virtualization constants (MAX_MOUNTED 260→120, OVERSCAN 40→20,
SLIDE_STEP 25→12) and cap historical-message render at 800 chars / 16
lines via HISTORY_RENDER_MAX_*; messages inside the FULL_RENDER_TAIL_ITEMS
window still render in full so reading-zone behavior is unchanged.
Validation, real-user CPU profile, page-up scroll on 11k-line session:
Output.get() self-time: 24% → 0.3%
sliceAnsi total: 18% → not in top 25
stringWidth family: 14% → ~3%
idle: 60.7% → 77.3%
Frame timings (synthetic page-up profile harness):
dur p95: ~10ms → 4.87ms
dur p99: 25ms+ → 12.80ms
yoga p99: ~20ms → 1.87ms
The remaining CPU in the profile is Yoga layoutNode + React commit,
which is the irreducible work for this UI tree size.
