feat(zen): read path optimizations for extreme performance

- Fast path for CLEAN state (skip _updateIfNecessary call)
- Inline track logic in Signal.get (avoid function call overhead)
- Extract state once in read() (avoid repeated bitwise ops)
- Optimized state checks with early returns

Target improvements:
- Single Read: >20M ops/sec (from 18.1M) - close gap with Solid 22.4M
- Extreme Read (10000x): >80K ops/sec (from 64K) - close gap with Solid 318K
- Computed Value Access: improve from 16.7M ops/sec

All 48 tests pass.

Author: shtse8

.changeset/read-optimizations.md

@@ -0,0 +1,19 @@
+---
+'@sylphx/zen': minor
+---
+
+Read path optimizations for extreme performance
+
+OPTIMIZATIONS:
+- Fast path for CLEAN state (skip _updateIfNecessary call)
+- Inline track logic in Signal.get (avoid function call overhead)
+- Extract state once in read() (avoid repeated bitwise ops)
+- Optimized state checks with early returns
+
+BENCHMARK TARGETS:
+- Single Read: Target >20M ops/sec (from 18.1M) - close gap with Solid 22.4M
+- Extreme Read (10000x): Target >80K ops/sec (from 64K) - close gap with Solid 318K
+- Moderate Read (100x): Maintain 4.9M ops/sec
+- Computed Value Access: Improve from 16.7M ops/sec
+
+These micro-optimizations reduce overhead in the hottest code paths (signal reads and computed value access).

packages/zen/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@sylphx/zen",
-  "version": "3.34.0",
-  "description": "Zen state management library - extreme minimalism, extreme speed. V3.33: Deep chain optimizations (early exit, CLEAN state setting, length caching).",
+  "version": "3.35.0",
+  "description": "Zen state management library - extreme minimalism, extreme speed. V3.35: Read path optimizations (fast CLEAN path, inline track, state extraction).",
   "type": "module",
   "main": "./dist/index.cjs",
   "module": "./dist/index.js",

packages/zen/src/zen.ts

@@ -242,16 +242,15 @@ class Computation<T> implements SourceType, ObserverType, Owner {
   }
 
   read(): T {
-    // Track this source in current observer
+    // OPTIMIZATION: Fast path for CLEAN state
+    const state = this._state & 3;
+
     if (currentObserver) {
       track(this);
-
-      // OPTIMIZATION: Only check if necessary
-      if (this._state & 3) {
+      if (state !== STATE_CLEAN) {
         this._updateIfNecessary();
       }
-    } else if (this._state & 3) {
-      // No observer - still need to update if dirty
+    } else if (state !== STATE_CLEAN && state !== STATE_DISPOSED) {
       this._updateIfNecessary();
     }
 
@@ -485,8 +484,20 @@ class Signal<T> implements SourceType {
   }
 
   get value(): T {
+    // OPTIMIZATION: Inline track check
     if (currentObserver) {
-      track(this);
+      // OPTIMIZATION: Compare with old sources first
+      if (
+        !newSources &&
+        currentObserver._sources &&
+        currentObserver._sources[newSourcesIndex] === this
+      ) {
+        newSourcesIndex++;
+      } else if (!newSources) {
+        newSources = [this];
+      } else if (this !== newSources[newSources.length - 1]) {
+        newSources.push(this);
+      }
     }
     return this._value;
   }