[PR #456] [CLOSED] perf(core): cache measureFunc results in TextBufferRenderable #1331

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opened 2026-03-14 09:30:54 +03:00 by kerem · 0 comments

kerem commented

2026-03-14 09:30:54 +03:00

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📋 Pull Request Information

Original PR: https://github.com/anomalyco/opentui/pull/456
Author: @remorses
Created: 12/29/2025
Status: ❌ Closed

Base: main ← Head: measure-cache-optimization

📝 Commits (6)

fa398bb perf(core): cache measureFunc results in TextBufferRenderable
ce214c9 fix: consistent height handling in measure cache hit/miss paths
36179a4 refactor: move measure cache to TextBufferView
a69497e fix: use unlimited height for measure cache to avoid truncation
35bc607 Merge branch 'main' into measure-cache-optimization
9d0e95e chore: restore Math.floor in measureForDimensions

📊 Changes

5 files changed (+213 additions, -2 deletions)

View changed files

📝 .gitignore (+1 -0)
➕ packages/core/src/benchmark/measure-cache-benchmark.ts (+169 -0)
📝 packages/core/src/renderables/TextBufferRenderable.ts (+0 -1)
📝 packages/core/src/text-buffer-view.ts (+31 -1)
📝 packages/core/src/text-buffer.ts (+12 -0)

📄 Description

Summary

Adds a measure cache to TextBufferRenderable to avoid redundant measureForDimensions calls during Yoga layout passes.

Why Yoga calls measureFunc multiple times:

During flexbox layout, Yoga probes nodes with different width constraints to determine optimal sizing:

First with Undefined mode to get intrinsic size
Then with AtMost to constrain to available space
Sometimes again with Exactly after resolving flex grow/shrink

This means measureForDimensions (which does text wrapping calculations) was being called 2-3x per layout pass per text node.

Solution:

Add _version counter to TextBuffer that increments on content changes
Cache measure results in TextBufferRenderable keyed by width
Invalidate cache when textBuffer.version changes or wrapMode changes

Benchmark results (144 text renderables in 8x6 grid):

Cached renders (no content change): 1.04ms avg
Uncached renders (content changes): 5.44ms avg

Cache speedup: 5.3x faster when content unchanged

References https://github.com/sst/opentui/pull/433#issuecomment-3697326260

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/anomalyco/opentui/pull/456 **Author:** [@remorses](https://github.com/remorses) **Created:** 12/29/2025 **Status:** ❌ Closed **Base:** `main` ← **Head:** `measure-cache-optimization` --- ### 📝 Commits (6) - [`fa398bb`](https://github.com/anomalyco/opentui/commit/fa398bbfdafd90737a7729e39bab7c2655f94a93) perf(core): cache measureFunc results in TextBufferRenderable - [`ce214c9`](https://github.com/anomalyco/opentui/commit/ce214c9b37f9aa61af0ccd14440f67e07898fe68) fix: consistent height handling in measure cache hit/miss paths - [`36179a4`](https://github.com/anomalyco/opentui/commit/36179a49bbb0c45356516eaa9f0fede15e5f2462) refactor: move measure cache to TextBufferView - [`a69497e`](https://github.com/anomalyco/opentui/commit/a69497ea66715a008ad4624b682d853e65ece7a0) fix: use unlimited height for measure cache to avoid truncation - [`35bc607`](https://github.com/anomalyco/opentui/commit/35bc607ae786b63b6bba92406715b0b860410487) Merge branch 'main' into measure-cache-optimization - [`9d0e95e`](https://github.com/anomalyco/opentui/commit/9d0e95ecde2c627351eb9293942fd989c8029560) chore: restore Math.floor in measureForDimensions ### 📊 Changes **5 files changed** (+213 additions, -2 deletions) <details> <summary>View changed files</summary> 📝 `.gitignore` (+1 -0) ➕ `packages/core/src/benchmark/measure-cache-benchmark.ts` (+169 -0) 📝 `packages/core/src/renderables/TextBufferRenderable.ts` (+0 -1) 📝 `packages/core/src/text-buffer-view.ts` (+31 -1) 📝 `packages/core/src/text-buffer.ts` (+12 -0) </details> ### 📄 Description ## Summary Adds a measure cache to `TextBufferRenderable` to avoid redundant `measureForDimensions` calls during Yoga layout passes. **Why Yoga calls measureFunc multiple times:** During flexbox layout, Yoga probes nodes with different width constraints to determine optimal sizing: 1. First with `Undefined` mode to get intrinsic size 2. Then with `AtMost` to constrain to available space 3. Sometimes again with `Exactly` after resolving flex grow/shrink This means `measureForDimensions` (which does text wrapping calculations) was being called 2-3x per layout pass per text node. **Solution:** - Add `_version` counter to `TextBuffer` that increments on content changes - Cache measure results in `TextBufferRenderable` keyed by width - Invalidate cache when `textBuffer.version` changes or `wrapMode` changes **Benchmark results (144 text renderables in 8x6 grid):** ``` Cached renders (no content change): 1.04ms avg Uncached renders (content changes): 5.44ms avg Cache speedup: 5.3x faster when content unchanged ``` References https://github.com/sst/opentui/pull/433#issuecomment-3697326260 --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>