90 lines
3.2 KiB
JavaScript
90 lines
3.2 KiB
JavaScript
// src/app.js onFilesChanged —— handler 并发闸（audit P1-4）
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//
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// 背景：原代码
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// const myToken = ++fsHandlerToken; // 自增但还没 SET
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// if (inFlightToken !== 0) { return; } // 检查还是 0
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// inFlightToken = myToken; // 才 SET
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// 两行间是 microtask 窗口：burst 50 events 时多个 callback 排在同一 microtask
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// queue 里，每个都看到 inFlightToken === 0，全部过闸 → handler 并发跑
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// （applyEntries 双跑、scanDir 双发、UI 闪烁）。
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//
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// 修复：抽 makeLock() 工厂 → { tryClaim, release, current }。tryClaim 是同步
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// 「check-and-set」原子操作：if 锁空闲则 SET 并返新 token，否则返 null。
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// 在 callback 入口 tryClaim → null 直接 return → 不再丢事件，统一存到
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// pendingRescanRel（既有逻辑保留）。
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//
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// 测试策略：直接 import 工厂函数，模拟 burst 场景验证「N 次 tryClaim 只有
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// 第一次成功」。
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import { describe, it, expect } from 'vitest';
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import { makeLock } from '../../src/fs-handler-lock.js';
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describe('fs-handler lock（audit P1-4）', () => {
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it('初始空闲 → tryClaim 返非零 token，current 反映该 token', () => {
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const lock = makeLock();
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const t = lock.tryClaim();
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expect(t).toBeGreaterThan(0);
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expect(lock.current()).toBe(t);
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});
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it('已占用时 tryClaim 返 null，current 不变', () => {
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const lock = makeLock();
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const t1 = lock.tryClaim();
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const t2 = lock.tryClaim();
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expect(t1).toBeGreaterThan(0);
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expect(t2).toBe(null);
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expect(lock.current()).toBe(t1);
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});
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it('release(token) → 锁重新空闲，tryClaim 能拿到新 token', () => {
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const lock = makeLock();
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const t1 = lock.tryClaim();
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expect(lock.release(t1)).toBe(true);
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expect(lock.current()).toBe(0);
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const t2 = lock.tryClaim();
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expect(t2).toBeGreaterThan(0);
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expect(t2).not.toBe(t1);
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});
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it('release(非当前 token) → 返 false，锁不被错误释放', () => {
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const lock = makeLock();
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const t1 = lock.tryClaim();
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expect(lock.release(99999)).toBe(false);
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expect(lock.current()).toBe(t1);
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});
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it('burst 50 次 tryClaim → 只有 1 次成功', () => {
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// 关键测试：模拟 microtask 批量场景
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const lock = makeLock();
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const results = Array.from({ length: 50 }, () => lock.tryClaim());
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const successes = results.filter((r) => r !== null);
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expect(successes).toHaveLength(1);
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// 其余 49 次全部 null
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expect(results.filter((r) => r === null)).toHaveLength(49);
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});
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it('release → tryClaim → 再 burst：交替可串行化多批事件', () => {
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const lock = makeLock();
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for (let batch = 0; batch < 5; batch++) {
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const t = lock.tryClaim();
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expect(t).not.toBe(null);
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// 本批 10 次并发全应被拒
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for (let i = 0; i < 10; i++) {
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expect(lock.tryClaim()).toBe(null);
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}
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// 释放
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expect(lock.release(t)).toBe(true);
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}
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});
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it('token 自增：每次成功 tryClaim 返的 token 都不同', () => {
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const lock = makeLock();
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const t1 = lock.tryClaim();
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lock.release(t1);
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const t2 = lock.tryClaim();
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lock.release(t2);
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const t3 = lock.tryClaim();
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expect(new Set([t1, t2, t3]).size).toBe(3);
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});
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});
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