perf(cmux-tui): avoid front-shifting layout nodes by lawrencecchen · Pull Request #11860 · manaflow-ai/cmux

lawrencecchen · 2026-09-03T14:14:23Z

Summary

Replace recursive Vec::remove(0) with VecDeque::pop_front in layout equality.
Preserve public APIs and pane order.

Verification

Existing layout order tests remain in place.
Rustfmt and diff checks pass.
Blacksmith Rust tests are pending.

^{Need help on this PR? Tag @codesmith-bot with what you need. Autofix is disabled.}

Summary by cubic

Speeds up layout construction in cmux-tui by replacing front-shifting Vec::remove(0) calls with VecDeque::pop_front(), so building equal-split trees is now O(1) per node instead of O(n). Public APIs and pane ordering are unchanged.

^{Written for commit 49001c3. Summary will update on new commits.}

Summary by CodeRabbit

Refactor
- Improved the internal layout tree construction process without changing user-visible layout behavior.

vercel · 2026-09-03T14:14:29Z

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
cmux166	Ready	Preview	Sep 3, 2026 11:37pm UTC
cmux41	Ready	Preview	Sep 3, 2026 11:37pm UTC

coderabbitai · 2026-09-03T14:14:33Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Team

Run ID: 43df1605-f0e0-42fa-9dd7-bc5226345567

📥 Commits

Reviewing files that changed from the base of the PR and between aaa600a and 49001c3.

📒 Files selected for processing (1)

cmux-tui/crates/cmux-tui-core/src/layout.rs

Included review availability: Your plan provides up to 10 included reviews per hour; 8 remain after this review.

📝 Walkthrough

Walkthrough

Changes

Layout Construction

Layer / File(s)	Summary
Use VecDeque for balanced node construction `cmux-tui/crates/cmux-tui-core/src/layout.rs`	The default Zellij layout converts its columns to `VecDeque`. `equal_nodes` consumes nodes with `pop_front` and uses explicit expectation messages.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: ⚪ Minimal · up to 49001

Balanced layout construction now consumes nodes efficiently with VecDeque while preserving pane ordering and layout behavior. No current merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 14 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (14 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main performance change: avoiding front-shifting layout nodes by replacing inefficient front removal.
Description check	✅ Passed	The description explains what changed, why it changed, and how it was verified. It also identifies that Blacksmith Rust tests are pending. The missing checklist and review-trigger sections are non-cri…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Cmux Swift Actor Isolation	✅ Passed	PASS: The pull request changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`, a Rust file. The complete `HEAD^..HEAD` diff contains no Swift paths. Therefore, the Swift actor-isolation check is i…
Cmux Swift Blocking Runtime	✅ Passed	PASS: The pull request changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`, a Rust file. The exact commit diff changes `Vec` to `VecDeque` and replaces `remove(0)` with `pop_front()`. It introd…
Cmux Browser Automation Off-Main	✅ Passed	PASS: The pull request changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`. The diff replaces `Vec::remove(0)` with `VecDeque::pop_front()` in `equal_nodes` and changes no browser command, sock…
Cmux Expensive Synchronous Load	✅ Passed	PASS: The pull request changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs` (5 additions, 5 deletions). It replaces Rust `Vec` front removal with `VecDeque::pop_front`; it adds no Swift code and…
Cmux Cache Substitution Correctness	✅ Passed	PASS: The pull request changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`, which is Rust. The custom check applies only to production Swift, TypeScript, and JavaScript changes. Therefore, its …
Cmux No Hacky Sleeps	✅ Passed	PASS: The PR changes only Rust code in `cmux-tui/crates/cmux-tui-core/src/layout.rs`. The diff replaces `Vec::remove(0)` with `VecDeque::pop_front()` and adds no TypeScript, JavaScript, shell, or buil…
Cmux Algorithmic Complexity	✅ Passed	PASS. The PR changes only Rust code in `cmux-tui-core/src/layout.rs`. It replaces `Vec::remove(0)` with `VecDeque::pop_front()` in `equal_nodes`, changing repeated front removal from quadratic behavio…
Cmux Swift Concurrency	✅ Passed	PASS: The pull-request diff changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`, which is Rust. It adds `VecDeque` and replaces `Vec::remove(0)` with `pop_front()` in `equal_nodes`. No Swift fi…
Cmux Swift `@Concurrent`	✅ Passed	PASS: The pull request changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`, a Rust file. The exact commit has `Rust=1`, `Swift=0`, and no Swift paths in its patch. The Swift concurrency rule th…
Cmux Swift Package Boundaries	✅ Passed	PASS: The exact PR commit changes only `cmux-tui/crates/cmux-tui-core/src/layout.rs`, a Rust file. The diff contains no `.swift` paths or Swift content changes. Therefore, the Swift package-boundary c…

Full details: Description check

Explanation

The description explains what changed, why it changed, and how it was verified. It also identifies that Blacksmith Rust tests are pending. The missing checklist and review-trigger sections are non-critical, and no demo is needed because this is an internal performance change without a UI change.

Full details: Cmux Swift Actor Isolation

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui-core/src/layout.rs, a Rust file. The complete HEAD^..HEAD diff contains no Swift paths. Therefore, the Swift actor-isolation check is inapplicable.

Full details: Cmux Swift Blocking Runtime

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui-core/src/layout.rs, a Rust file. The exact commit diff changes Vec to VecDeque and replaces remove(0) with pop_front(). It introduces no Swift file or Swift blocking/timing primitive, so the custom check is not applicable.

Full details: Cmux Browser Automation Off-Main

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui-core/src/layout.rs. The diff replaces Vec::remove(0) with VecDeque::pop_front() in equal_nodes and changes no browser command, socket-worker policy, WebKit/AppKit access, main-actor routing, or policy tests. The custom check is therefore not applicable.

Full details: Cmux Expensive Synchronous Load

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui-core/src/layout.rs (5 additions, 5 deletions). It replaces Rust Vec front removal with VecDeque::pop_front; it adds no Swift code and no agent-history load or interactive-path call. The custom check does not apply.

Full details: Cmux Cache Substitution Correctness

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui-core/src/layout.rs, which is Rust. The custom check applies only to production Swift, TypeScript, and JavaScript changes. Therefore, its cache-substitution failure condition is not applicable.

Full details: Cmux No Hacky Sleeps

Explanation

PASS: The PR changes only Rust code in cmux-tui/crates/cmux-tui-core/src/layout.rs. The diff replaces Vec::remove(0) with VecDeque::pop_front() and adds no TypeScript, JavaScript, shell, or build/runtime-script changes. The custom check applies only to those non-Swift languages, so no hacky-sleep failure condition is applicable.

Full details: Cmux Algorithmic Complexity

Explanation

PASS. The PR changes only Rust code in cmux-tui-core/src/layout.rs. It replaces Vec::remove(0) with VecDeque::pop_front() in equal_nodes, changing repeated front removal from quadratic behavior to linear behavior. The change does not introduce any forbidden scan, rescan, sort, filter, join, or slower algorithm.

Full details: Cmux Swift Concurrency

Explanation

PASS: The pull-request diff changes only cmux-tui/crates/cmux-tui-core/src/layout.rs, which is Rust. It adds VecDeque and replaces Vec::remove(0) with pop_front() in equal_nodes. No Swift file or Swift concurrency pattern changed, so this check is inapplicable.

Full details: Cmux Swift `@Concurrent`

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui-core/src/layout.rs, a Rust file. The exact commit has Rust=1, Swift=0, and no Swift paths in its patch. The Swift concurrency rule therefore does not apply.

Full details: Cmux Swift Package Boundaries

Explanation

PASS: The exact PR commit changes only cmux-tui/crates/cmux-tui-core/src/layout.rs, a Rust file. The diff contains no .swift paths or Swift content changes. Therefore, the Swift package-boundary check is not applicable.

Fix all pre-merge checks with AI

✨ Finishing Touches 💡 1

📝 Generate docstrings 💡

Create stacked PR
Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch feat-tui-layout-vecdeque

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

_{Comment @coderabbitai help to get the list of available commands.}

github-actions · 2026-09-03T14:14:36Z

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

3812562 refactor(tui): centralize terminal input classification (manaflow-ai#11855) 7d0385f Axiom: failure rate and latency per third-party endpoint (Freestyle, Stack Auth, Stripe, ...) (manaflow-ai#11779) ed5e826 refactor(tui): share frontend focus target mapping (manaflow-ai#11861) 7fa300e Revert "Fix terminal text bleed during live window resize (manaflow-ai#11530)" (manaflow-ai#11887) bace77c perf(cmux-tui): avoid front-shifting layout nodes (manaflow-ai#11860) 9f8a74f cmux-tui: simplify PTY error mapping (manaflow-ai#11864) 2748329 refactor(cmux-tui): share stack row allocation (manaflow-ai#11867) e7223a5 coderouter: PostHog traces + exceptions keyed by the cmux user, request ids, health endpoint, Slack alerts, upstream header timeout (manaflow-ai#11798)

lawrencecchen force-pushed the feat-tui-layout-vecdeque branch from 6ff7205 to 23b96c1 Compare September 3, 2026 14:39

vercel Bot deployed to Preview – cmux166 September 3, 2026 20:18 View deployment

vercel Bot deployed to Preview – cmux41 September 3, 2026 20:19 View deployment

perf(cmux-tui): avoid front-shifting layout nodes

49001c3

lawrencecchen force-pushed the feat-tui-layout-vecdeque branch from 23b96c1 to 49001c3 Compare September 3, 2026 23:32

vercel Bot deployed to Preview – cmux41 September 3, 2026 23:37 View deployment

vercel Bot deployed to Preview – cmux166 September 3, 2026 23:37 View deployment

lawrencecchen merged commit bace77c into main Sep 3, 2026
53 checks passed

aerickson pushed a commit to aerickson/cmux that referenced this pull request Sep 13, 2026

perf(cmux-tui): avoid front-shifting layout nodes (manaflow-ai#11860)

cb83eeb

Navigation Menu

Uh oh!

perf(cmux-tui): avoid front-shifting layout nodes - #11860

perf(cmux-tui): avoid front-shifting layout nodes#11860
lawrencecchen merged 1 commit into
mainfrom
feat-tui-layout-vecdeque

lawrencecchen commented Sep 3, 2026 •

edited by coderabbitai Bot

Loading

Uh oh!

vercel Bot commented Sep 3, 2026 •

edited

Loading

Uh oh!

coderabbitai Bot commented Sep 3, 2026 •

edited

Loading

Walkthrough

Changes

❌ Failed checks (1 warning)

Uh oh!

github-actions Bot commented Sep 3, 2026

Uh oh!

Uh oh!

This branch was successfully deployed

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Uh oh!

Conversation

lawrencecchen commented Sep 3, 2026 • edited by coderabbitai Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary by cubic

Summary by CodeRabbit

Uh oh!

vercel Bot commented Sep 3, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

coderabbitai Bot commented Sep 3, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Walkthrough

Changes

❌ Failed checks (1 warning)

Uh oh!

github-actions Bot commented Sep 3, 2026

Uh oh!

Uh oh!

This branch was successfully deployed

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

lawrencecchen commented Sep 3, 2026 •

edited by coderabbitai Bot

Loading

vercel Bot commented Sep 3, 2026 •

edited

Loading

coderabbitai Bot commented Sep 3, 2026 •

edited

Loading