Merge pull request 'fix: MKH-BOM 修复在途旧查询回写缓存，导致「同步最新数据」点完仍是旧数据' (#20) from codex/mkh-cache-stale-write-fix-0922 into main

backend/src/services/mkhBomService.js

@@ -360,6 +360,21 @@ const officialBomDetailCache = new Map();
 const componentLocationCache = new Map();
 let productBomCache = null;
 
+/**
+ * 缓存代际（epoch）：`clearMkhBomCache()` 每次自增。
+ *
+ * 为什么需要它 ——「同步最新数据」按钮点完反而看到旧数据：
+ *   所有缓存都是「先挂 pending，await 到结果后无条件写回」的写法。若在某个查询
+ *   in-flight 期间用户点了同步（清空全部缓存），那个**发起于清缓存之前**的查询
+ *   读到的仍是旧快照，它返回时会无条件把旧值写回缓存，把清缓存后新请求填入的
+ *   新值覆盖掉 —— 之后 2~10 分钟（各缓存 TTL）内页面持续显示旧数据。
+ *   并发越高（多人同时用、或先点刷新再点同步）越容易撞上。
+ *
+ * 修法：查询发起时记下当时的 epoch，写回前比对；epoch 变了说明中途被清过缓存，
+ *   这次结果已经过期，**只返回给发起它的那个请求，不写缓存**。
+ */
+let cacheEpoch = 0;
+
 // MKH 模块化成品必须同时是指定仓库商品档案和正式 BOM 父项。
 // 上游存在被 item_type/labels 误标为成品的配件，不能仅依赖商品档案标签。
 const DESIGNATED_WAREHOUSE = '简尚-崔桥工厂品牌仓';
@@ -742,13 +757,18 @@ async function loadOfficialBomIndex() {
     return { bySku, bySpuPrefix: [], entries: [] };
   });
 
+  const epoch = cacheEpoch;
   officialBomIndexCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    officialBomIndexCache = { pending: null, value, expiresAt: Date.now() + BOM_CACHE_TTL_MS };
+    // epoch 变了 ⇒ 期间用户点过「同步最新数据」，本次结果来自清缓存前的旧快照，
+    // 只还给发起它的请求，不写回缓存（否则会把新值覆盖成旧值）
+    if (epoch === cacheEpoch) {
+      officialBomIndexCache = { pending: null, value, expiresAt: Date.now() + BOM_CACHE_TTL_MS };
+    }
     return value;
   } catch (error) {
-    officialBomIndexCache = null;
+    if (epoch === cacheEpoch) officialBomIndexCache = null;
     throw error;
   }
 }
@@ -765,6 +785,8 @@ async function loadOfficialBomForSkus(skuIds = []) {
       .filter(([key, value]) => key && value)
   ).entries()).slice(0, MAX_PAGE_SIZE);
   const now = Date.now();
+  // 见 cacheEpoch 注释：清缓存后才返回的旧查询结果不得写回缓存
+  const epoch = cacheEpoch;
   const missing = requested.filter(([key]) => {
     const cached = officialBomDetailCache.get(key);
     return !cached || cached.expiresAt <= now;
@@ -795,11 +817,14 @@ async function loadOfficialBomForSkus(skuIds = []) {
     );
     const grouped = groupOfficialBomRows(rows);
     const expiresAt = Date.now() + OFFICIAL_BOM_DETAIL_CACHE_TTL_MS;
+    const writable = epoch === cacheEpoch;
     missing.forEach(([key]) => {
-      officialBomDetailCache.set(key, {
+      if (writable) {
-        components: grouped.bySku.get(key) || [],
+        officialBomDetailCache.set(key, {
-        expiresAt,
+          components: grouped.bySku.get(key) || [],
-      });
+          expiresAt,
+        });
+      }
     });
   }
 
@@ -856,13 +881,16 @@ async function loadBusinessBom() {
     return bom;
   });
 
+  const epoch = cacheEpoch;
   businessBomCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    businessBomCache = { pending: null, value, expiresAt: Date.now() + BOM_CACHE_TTL_MS };
+    if (epoch === cacheEpoch) {
+      businessBomCache = { pending: null, value, expiresAt: Date.now() + BOM_CACHE_TTL_MS };
+    }
     return value;
   } catch (error) {
-    businessBomCache = null;
+    if (epoch === cacheEpoch) businessBomCache = null;
     throw error;
   }
 }
@@ -939,13 +967,16 @@ async function loadPgBom() {
     return { bySku, bySpuPrefix, entries };
   })();
 
+  const epoch = cacheEpoch;
   productBomCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    productBomCache = { pending: null, value, expiresAt: Date.now() + BOM_CACHE_TTL_MS };
+    if (epoch === cacheEpoch) {
+      productBomCache = { pending: null, value, expiresAt: Date.now() + BOM_CACHE_TTL_MS };
+    }
     return value;
   } catch (error) {
-    productBomCache = null;
+    if (epoch === cacheEpoch) productBomCache = null;
     throw error;
   }
 }
@@ -1283,13 +1314,16 @@ async function loadMkhProductIndex() {
     material: toText(row.material),
   })).filter((row) => row.skuId));
 
+  const epoch = cacheEpoch;
   mkhProductCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    mkhProductCache = { pending: null, value, expiresAt: Date.now() + MKH_CACHE_TTL_MS };
+    if (epoch === cacheEpoch) {
+      mkhProductCache = { pending: null, value, expiresAt: Date.now() + MKH_CACHE_TTL_MS };
+    }
     return value;
   } catch (error) {
-    mkhProductCache = null;
+    if (epoch === cacheEpoch) mkhProductCache = null;
     throw error;
   }
 }
@@ -1350,13 +1384,16 @@ async function loadPendingWorkOrderIndex() {
     return { bySku: new Map(), degraded: true, error: error.message, ttl: WORK_ORDER_DEGRADED_TTL_MS };
   });
 
+  const epoch = cacheEpoch;
   workOrderIndexCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    workOrderIndexCache = { pending: null, value, expiresAt: Date.now() + value.ttl };
+    if (epoch === cacheEpoch) {
+      workOrderIndexCache = { pending: null, value, expiresAt: Date.now() + value.ttl };
+    }
     return value;
   } catch (error) {
-    workOrderIndexCache = null;
+    if (epoch === cacheEpoch) workOrderIndexCache = null;
     throw error;
   }
 }
@@ -1642,13 +1679,16 @@ async function loadOrderIndex() {
     return { pendingBySku, shippedBySku, degraded: false, error: null, ttl: MKH_CACHE_TTL_MS };
   });
 
+  const epoch = cacheEpoch;
   orderIndexCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    orderIndexCache = { pending: null, value, expiresAt: Date.now() + value.ttl };
+    if (epoch === cacheEpoch) {
+      orderIndexCache = { pending: null, value, expiresAt: Date.now() + value.ttl };
+    }
     return value;
   } catch (error) {
-    orderIndexCache = null;
+    if (epoch === cacheEpoch) orderIndexCache = null;
     throw error;
   }
 }
@@ -1751,13 +1791,16 @@ async function loadReplenishIndex() {
     };
   });
 
+  const epoch = cacheEpoch;
   replenishIndexCache = { pending, value: null, expiresAt: 0 };
   try {
     const value = await pending;
-    replenishIndexCache = { pending: null, value, expiresAt: Date.now() + MKH_CACHE_TTL_MS };
+    if (epoch === cacheEpoch) {
+      replenishIndexCache = { pending: null, value, expiresAt: Date.now() + MKH_CACHE_TTL_MS };
+    }
     return value;
   } catch (error) {
-    replenishIndexCache = null;
+    if (epoch === cacheEpoch) replenishIndexCache = null;
     throw error;
   }
 }
@@ -1772,6 +1815,8 @@ async function loadReplenishIndex() {
  */
 async function loadComponentStock(codes = []) {
   const now = Date.now();
+  // 见 cacheEpoch 注释：清缓存后才返回的旧查询结果不得写回缓存
+  const epoch = cacheEpoch;
   const unique = Array.from(new Set(codes.map((code) => toText(code)).filter(Boolean)));
   const stockMap = new Map();
   const missing = [];
@@ -1806,9 +1851,11 @@ async function loadComponentStock(codes = []) {
         if (code) found.set(code, toNumber(row.qty) ?? 0);
       });
       const expiresAt = Date.now() + COMPONENT_STOCK_CACHE_TTL_MS;
+      const writable = epoch === cacheEpoch;
       chunk.forEach((code) => {
         const qty = found.get(code) ?? 0;
-        componentStockCache.set(code, { qty, expiresAt });
+        // 本批结果仍要返回给调用方（stockMap），只是不再写缓存
+        if (writable) componentStockCache.set(code, { qty, expiresAt });
         stockMap.set(code, qty);
       });
     } catch (error) {
@@ -2019,6 +2066,8 @@ function buildPackLocationMap(rows, componentCodes) {
  */
 async function loadComponentLocations(codes = []) {
   const now = Date.now();
+  // 见 cacheEpoch 注释：清缓存后才返回的旧查询结果不得写回缓存
+  const epoch = cacheEpoch;
   const unique = Array.from(new Set(codes.map((code) => toText(code)).filter(Boolean)));
   const locationMap = new Map();
   const missing = [];
@@ -2065,9 +2114,11 @@ async function loadComponentLocations(codes = []) {
       );
       const byCode = buildPackLocationMap(rows, chunk);
       const expiresAt = Date.now() + COMPONENT_LOCATION_CACHE_TTL_MS;
+      const writable = epoch === cacheEpoch;
       chunk.forEach((code) => {
         const location = byCode.get(code) || null;
-        componentLocationCache.set(code, { location, expiresAt });
+        // 本批结果仍要返回给调用方（locationMap），只是不再写缓存
+        if (writable) componentLocationCache.set(code, { location, expiresAt });
         if (location) locationMap.set(code, location);
       });
     } catch (error) {
@@ -2405,6 +2456,11 @@ async function listMkhBomExportRows(query = {}) {
 // 而不是 2~15 分钟前的缓存结果。
 // 注意：副本库本身由聚水潭侧同步，应用层无法触发上游拉取，本函数只保证「不读旧缓存」。
 function clearMkhBomCache() {
+  // 🔥 先自增代际，再清各缓存：这样「本次清缓存之前已经发起、还没返回」的查询，
+  //    回来时 epoch 对不上，就不会把旧快照写回缓存（否则会覆盖掉清缓存后新查到的值，
+  //    导致按钮点完反而 2~10 分钟一直显示旧数据）。
+  cacheEpoch += 1;
+
   businessBomCache = null;
   officialBomIndexCache = null;
   productBomCache = null;
@@ -2424,6 +2480,7 @@ function clearMkhBomCache() {
 
   return {
     syncedAt: new Date().toISOString(),
+    cacheEpoch,
     cleared: cleared.map(([name, entries]) => ({ name, entries })),
   };
 }

backend/test/mkhBomService.test.js

@@ -1167,3 +1167,100 @@ test('export: 配件不足 rows are flagged and carry no replenish target', () =
   // 可组装数一并导出，便于业务核对短板
   assert.equal(rows[0].assemblableQty, 0);
 });
+
+// ─────────────────────────────────────────────────────────────────────────────
+// 缓存代际（cacheEpoch）：修复「点同步最新数据，反而显示旧数据」
+//
+// 症状：用户点「同步最新数据」后，页面 2~10 分钟内持续显示旧值，像在用缓存。
+// 成因：缓存是「先挂 pending → await 结果 → 无条件写回」。若某个查询在途时用户点了
+//       同步（清空缓存），那个发起于清缓存之前的查询读到的是旧快照，返回时会把旧值
+//       写回缓存，覆盖掉清缓存后新请求填入的新值 —— 谁后完成谁生效。
+//
+// 下面第一个用例复现旧行为（修复前失败），第二个用例锁定正确语义。
+// ─────────────────────────────────────────────────────────────────────────────
+
+test('cache epoch: 清缓存后在途的旧查询结果不得写回缓存（否则同步按钮点完仍是旧数据）', async () => {
+  const cloudDatabase = require('../src/config/cloudDatabase');
+  const svc = require('../src/services/mkhBomService');
+  const originalQuery = cloudDatabase.query;
+
+  const CODE = 'DNZTESTCACHE01';
+  const staleQty = 9; // 清缓存前那一刻库里/旧快照的值
+  const freshQty = 1; // 清缓存后重新查到的值
+
+  let phase = 'old';
+  let stockQueries = 0;
+  let releaseStale;
+  const staleGate = new Promise((resolve) => { releaseStale = resolve; });
+  let markStaleStarted;
+  const staleStarted = new Promise((resolve) => { markStaleStarted = resolve; });
+
+  cloudDatabase.query = async (sql) => {
+    if (!sql.includes('jst_inventoryInfo')) return [];
+    stockQueries += 1;
+    if (phase === 'old') {
+      markStaleStarted();
+      await staleGate; // 卡住旧查询：模拟「发起于此、期间用户点了同步」的慢查询
+      return [{ code: CODE, qty: staleQty }];
+    }
+    return [{ code: CODE, qty: freshQty }];
+  };
+
+  try {
+    // 1) 旧查询发起并卡住
+    const inFlight = svc._private.loadComponentStock([CODE]);
+    await staleStarted;
+
+    // 2) 用户点「同步最新数据」→ 清缓存并推进代际
+    const cleared = svc.clearMkhBomCache();
+    assert.ok(cleared.cacheEpoch >= 1, '清缓存必须推进代际号');
+    phase = 'new';
+
+    // 3) 清缓存后的新查询先返回，拿到新值并写缓存
+    const fresh = await svc._private.loadComponentStock([CODE]);
+    assert.equal(fresh.stockMap.get(CODE), freshQty);
+    assert.equal(stockQueries, 2, '清缓存后必须真正重查数据源');
+
+    // 4) 旧查询这才返回（它读到的仍是旧快照）
+    releaseStale();
+    const staleResult = await inFlight;
+    assert.equal(staleResult.stockMap.get(CODE), staleQty,
+      '过期结果仍应原样返回给发起它的那个请求，不能改变它自己的语义');
+
+    // 5) 🔥 关键断言：缓存里必须还是新值
+    const after = await svc._private.loadComponentStock([CODE]);
+    assert.equal(after.stockMap.get(CODE), freshQty,
+      '清缓存后返回的过期结果写回了缓存 → 用户会看到「点了同步还是旧数据」');
+    assert.equal(stockQueries, 2,
+      '第 5 步应直接命中缓存，不应再打数据库（说明缓存确实被写入了新值）');
+  } finally {
+    cloudDatabase.query = originalQuery;
+    svc.clearMkhBomCache();
+  }
+});
+
+test('cache epoch: 未经清缓存时缓存照常命中（回归保护）', async () => {
+  const cloudDatabase = require('../src/config/cloudDatabase');
+  const svc = require('../src/services/mkhBomService');
+  const originalQuery = cloudDatabase.query;
+
+  const CODE = 'DNZTESTCACHE02';
+  let stockQueries = 0;
+  cloudDatabase.query = async (sql) => {
+    if (!sql.includes('jst_inventoryInfo')) return [];
+    stockQueries += 1;
+    return [{ code: CODE, qty: 3 }];
+  };
+
+  try {
+    svc.clearMkhBomCache();
+    const first = await svc._private.loadComponentStock([CODE]);
+    const second = await svc._private.loadComponentStock([CODE]);
+    assert.equal(first.stockMap.get(CODE), 3);
+    assert.equal(second.stockMap.get(CODE), 3);
+    assert.equal(stockQueries, 1, '同一次缓存代际内，第二次必须命中缓存不再查库');
+  } finally {
+    cloudDatabase.query = originalQuery;
+    svc.clearMkhBomCache();
+  }
+});