[markovejnovic]

Each read of the child's output went through up to four parsers: the debug highlighter's on the output task, then capture's and the highlighter's again on the emulator thread. All of them were markers.rs, a hand-written scanner. markers.rs becomes parser.rs, which follows the output with atuin-vte, Atuin's fork of vte. atuin-vt100 0.19.2 is built on it too, so the stream parser reads the output as the emulator does.

Behaviour changes

• 0x9C no longer ends a marker. A UTF-8 terminal reads it as part of a character, and every shell integration ends its markers with BEL. No user-facing change. Our shell integrations use BEL anyways and it's unclear to me why we handled 0x9C.
• Controls inside a marker are left out of it, and a marker that CAN or SUB cuts off, or that any ESC ends, counts as sent. No user-facing change. Our shell integrations do not send any controls inside markers.
• An unfinished OSC is held whole, rather than its first bytes. vte doesn't cap it, so neither the emulator (as on main) nor the parser does; a cap belongs in atuin-vte. This means that memory usage of the pty-proxy with malicious applications grows unbounded. main had this bug, except that it was only in the emulator.rs codepath.

Performance

• P50 keystroke latency increased by 30%. This is due to vte's performance problems. It is around 30us on my machine now.
• P99 keystroke latency is unchanged.
• Throughput is unchanged.
• Pty-proxy under adversarial workloads uses about 2% more CPU on average.

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; no new blocking issue was established.

Summary

The PR parses child output once and shares Output with capture, debug labels, and the screen.

• The PTY proxy parses child output once and shares marker events.

_{Reviews (5) · Last reviewed commit: "refactor(pty-proxy): parse with atuin-vt..." · Reviewed by Greptile}

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	cargo/​atuin-vte@​0.15.1
	cargo/​atuin-vt100@​0.19.1 ⏵ 0.19.2

View full report

[markovejnovic]

/merge

[atuin-bot]

Landed as af714d0. GitHub shows this merged once it reaches main.