Reduce React effect store allocations

[JoviDeCroock]

Each mounted React component currently owns closures for every EffectStore method. Move the render-only methods to a shared prototype while keeping subscribe and getSnapshot as direct per-instance closures.

The hybrid shape avoids bound-call overhead, removes 224 B per mounted component, and adds 29 B gzip to runtime.mjs.

React EffectStore — 45.0% faster creation, 44.3% faster render cycle, 224 B smaller

import { effect } from "@preact/signals-core";

function HybridStore() {
  let effectInstance;
  let version = 0;
  let onChange;
  this._endEffect = undefined;

  const unsubscribe = effect(function () {
    effectInstance = this;
  });
  this.effect = effectInstance;
  effectInstance._callback = () => {
    version = (version + 1) | 0;
    onChange?.();
  };
  this.subscribe = function (fn) {
    onChange = fn;
    return () => {
      version = (version + 1) | 0;
      onChange = undefined;
      unsubscribe();
    };
  };
  this.getSnapshot = function () {
    return version;
  };
}
HybridStore.prototype._start = function () {
  this._endEffect = this.effect._start();
};
HybridStore.prototype.f = function () {
  const end = this._endEffect;
  this._endEffect = undefined;
  end?.();
};

const stores = Array.from({ length: 200_000 }, () => new HybridStore());
const start = performance.now();
for (const store of stores) {
  store._start();
  store.f();
}
console.log(performance.now() - start);

[changeset-bot]

🦋 Changeset detected

Latest commit: 3ba2e2f

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@preact/signals-react	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

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[github-actions]

Size Change: +2 B (0%)

Total Size: 199 kB

📦 View Changed

Filename	Size	Change
docs/dist/assets/client-********.js	46.6 kB	+1 B (0%)
docs/dist/react-********.js	243 B	+1 B (+0.41%)

ℹ️ View Unchanged

Filename	Size
docs/dist/assets/bench-********.js	1.6 kB
docs/dist/assets/devtools-********.js	911 B
docs/dist/assets/EmbeddedDevtools-********.js	23 kB
docs/dist/assets/index-********.js	540 B
docs/dist/assets/jsxRuntime.module-********.js	300 B
docs/dist/assets/preact.module-********.js	4.74 kB
docs/dist/assets/signals-core.module-********.js	1.92 kB
docs/dist/assets/signals.module-********.js	2.66 kB
docs/dist/assets/style-********.css	7.19 kB
docs/dist/assets/Unmount-********.js	651 B
docs/dist/assets/utils.module-********.js	520 B
docs/dist/basic-********.js	247 B
docs/dist/nesting-********.js	1.15 kB
packages/core/dist/signals-core.js	1.94 kB
packages/core/dist/signals-core.mjs	1.93 kB
packages/debug/dist/debug.js	4.72 kB
packages/debug/dist/debug.mjs	4.24 kB
packages/devtools-adapter/dist/devtools-adapter.js	2.36 kB
packages/devtools-adapter/dist/devtools-adapter.mjs	2.07 kB
packages/devtools-ui/dist/devtools-ui.js	21.3 kB
packages/devtools-ui/dist/devtools-ui.mjs	20.6 kB
packages/preact-transform/dist/signals-transform.js	1.66 kB
packages/preact-transform/dist/signals-transform.mjs	1.61 kB
packages/preact-transform/dist/signals-transform.umd.js	1.77 kB
packages/preact/dist/signals.js	1.82 kB
packages/preact/dist/signals.mjs	1.76 kB
packages/react-transform/dist/signals-transform.js	7.63 kB
packages/react-transform/dist/signals-transform.mjs	6.78 kB
packages/react-transform/dist/signals-transform.umd.js	7.75 kB
packages/react/dist/signals.js	214 B
packages/react/dist/signals.mjs	165 B
packages/vite-plugin/dist/vite-plugin.js	8.86 kB
packages/vite-plugin/dist/vite-plugin.mjs	7.86 kB

_{compressed-size-action}