Avoid cloning occluders during graphics cache checks

[lawrencecchen]

Summary:

• Compare graphics cache context fields directly against the freshly computed occluder slice.
• Move the original occluder Vec into the cache only when the context changes.

Validation:

• git diff --check
• Remote Blacksmith cargo test --locked graphics_scene_cache (2 tests passed)
• Hosted cmux-tui focused verification dispatched for this commit

No new test was added because allocation behavior has no independent user-visible assertion; existing graphics scene cache tests cover the unchanged and changed context paths.

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Summary by cubic

Stops cloning the occluder list when checking the graphics scene cache. The cache check now compares the cached fields directly against the freshly computed occluders and moves the Vec into the cache only when the context changes, cutting per-frame allocations with no behavior change.

^{Written for commit 336cab7. Summary will update on new commits.}

Summary by CodeRabbit

• Performance
  • Improved graphics scene cache comparisons by reducing temporary state and redundant processing.
  • Improved rendering update efficiency when occlusion information changes.

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Project	Deployment	Actions	Updated
cmux166	Canceled		Sep 3, 2026 3:29pm UTC
cmux41	Canceled		Sep 3, 2026 3:29pm UTC

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ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 18bec20 and 336cab7.

📒 Files selected for processing (1)

• cmux-tui/crates/cmux-tui/src/app.rs

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📝 Walkthrough

Walkthrough

The graphics scene context check computes occluders once and compares them directly with cached values. The cache update moves the computed occluders into the stored GraphicsSceneContextKey.

Changes

Graphics context cache

Layer / File(s)	Summary
Direct occluder comparison and cache update cmux-tui/crates/cmux-tui/src/app.rs	The context check compares cached fields directly with current values. The cache update moves the computed occluders into the stored key.

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

Merge Risk: ⚪ Minimal · up to 336ca

This change removes a redundant occluder-vector clone while preserving graphics cache invalidation behavior. The updated cache paths are covered by existing focused tests, with no remaining merge-readiness risk identified.

Suggested reviewers: lawrence703

🚥 Pre-merge checks | ✅ 15

✅ Passed checks (15 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main change: avoiding unnecessary cloning of occluders during graphics cache checks.
Description check	✅ Passed	The description explains what changed, why it changed, and how it was validated. It does not use the template headings and omits the review trigger and checklist, but the required technical context is…
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
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/src/app.rs, a Rust file. The exact commit has no changed Swift files or Swift actor-isolation declarations. The Swift actor-isolation che…
Cmux Swift Blocking Runtime	✅ Passed	PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, which is Rust. The parent-to-HEAD diff introduces no Swift files or Swift blocking/timing primitives. The custom check is the…
Cmux Browser Automation Off-Main	✅ Passed	PASS: The commit changes only cmux-tui/crates/cmux-tui/src/app.rs. The diff updates graphics occluder cache comparison and GraphicsSceneContextKey construction. It does not modify `Sources/Termina…
Cmux Expensive Synchronous Load	✅ Passed	PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust file. The diff adjusts graphics occluder cache comparison and ownership. It adds or moves no production Swift code and…
Cmux Cache Substitution Correctness	✅ Passed	PASS. The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, which is Rust; the changed-path check found no Swift, TypeScript, or JavaScript files. The custom check applies only to produ…
Cmux No Hacky Sleeps	✅ Passed	PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust source file. The custom check applies to TypeScript, JavaScript, shell, and non-Swift build/runtime scripts. The diff …
Cmux Algorithmic Complexity	✅ Passed	PASS. The only changed file is Rust source, and the diff replaces a cloned Vec<Rect> with one direct slice comparison. That comparison remains linear and does not add a nested scan, repeated sorting…
Cmux Swift Concurrency	✅ Passed	PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust file. The commit diff has no .swift paths and introduces no Swift concurrency patterns. The Swift concurrency check …
Cmux Swift @Concurrent	✅ Passed	PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust file. The exact diff contains no Swift files, Swift functions, or Swift call sites. Therefore the @concurrent check …
Cmux Swift Package Boundaries	✅ Passed	PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, which is Rust. No Swift file or Swift package boundary is changed. The custom check applies only to production Swift changes.

Full details: Description check

Explanation

The description explains what changed, why it changed, and how it was validated. It does not use the template headings and omits the review trigger and checklist, but the required technical context is present.

Full details: Docstring Coverage

Explanation

No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0 files. (1 skipped: 1 too large.)

Full details: Cmux Swift Actor Isolation

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust file. The exact commit has no changed Swift files or Swift actor-isolation declarations. The Swift actor-isolation check is therefore inapplicable.

Full details: Cmux Swift Blocking Runtime

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, which is Rust. The parent-to-HEAD diff introduces no Swift files or Swift blocking/timing primitives. The custom check is therefore not applicable.

Full details: Cmux Browser Automation Off-Main

Explanation

PASS: The commit changes only cmux-tui/crates/cmux-tui/src/app.rs. The diff updates graphics occluder cache comparison and GraphicsSceneContextKey construction. It does not modify Sources/TerminalController.swift or Packages/macOS/CmuxControlSocket/Sources/CmuxControlSocket/Wire/ControlCommandExecutionPolicy.swift, and the changed hunk contains no browser socket command, WebKit/page wait, worker routing, or main-actor routing change. 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/src/app.rs, a Rust file. The diff adjusts graphics occluder cache comparison and ownership. It adds or moves no production Swift code and no synchronous agent-history load.

Full details: Cmux Cache Substitution Correctness

Explanation

PASS. The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, which is Rust; the changed-path check found no Swift, TypeScript, or JavaScript files. The custom check applies only to production Swift, TypeScript, and JavaScript changes, so it is not applicable.

Full details: Cmux No Hacky Sleeps

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust source file. The custom check applies to TypeScript, JavaScript, shell, and non-Swift build/runtime scripts. The diff does not introduce a covered fixed sleep, timer, polling wait, or delayed dispatch.

Full details: Cmux Algorithmic Complexity

Explanation

PASS. The only changed file is Rust source, and the diff replaces a cloned Vec<Rect> with one direct slice comparison. That comparison remains linear and does not add a nested scan, repeated sorting/filtering, or a slower algorithm. The existing per-placement occluder scan in graphic_placements_for_area is unchanged. The diff also moves the original vector into the cache only on context change, so it does not worsen existing complexity.

Full details: Cmux Swift Concurrency

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust file. The commit diff has no .swift paths and introduces no Swift concurrency patterns. The Swift concurrency check is therefore not applicable.

Full details: Cmux Swift `@Concurrent`

Explanation

PASS: The pull request changes only cmux-tui/crates/cmux-tui/src/app.rs, a Rust file. The exact diff contains no Swift files, Swift functions, or Swift call sites. Therefore the @concurrent check is not applicable.

✨ Finishing Touches

📝 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-graphics-context-cache

Warning

Some tools did not complete. Review the errors below.

🔧 ast-grep (0.45.2)

cmux-tui/crates/cmux-tui/src/app.rs

ast-grep timed out on this file

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[lawrencecchen]

Correctness and allocation note: graphic_occlusion_rects() still creates one fresh Vec<Rect> per graphics emit call. This patch removes only the duplicate occluders.clone() allocation. The temporary vector is borrowed while placements are built, then moved into GraphicsSceneContextKey only when context_changed is true. Cache invalidation paths and key fields are unchanged, and the existing cache tests cover unchanged and changed context paths. No allocation benchmark was added because the test API has no stable allocation counter. A future profile can assess reusing scratch storage or comparing iterators.

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Note

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