perf(packages): 优化 /api/packages 7000+ 条响应性能

- buildPackages 缓存全量结果（rawCache/ignored/threshold 不变时复用）

- gzip 压缩大响应（Node 内置 zlib，减少传输体积 60-80%）

backend/scan-manager.js

@@ -28,6 +28,9 @@ export function isDemoMode() {
 let rawCache = null
 let rawCacheAt = null
 
+// 包列表构建缓存（rawCache/ignored/threshold 不变时复用，避免每次请求全量 map 7000+ 条）
+let packagesCache = null
+
 // —— 异步扫描状态（后台重扫时供前端轮询进度） ——
 export const scanState = {
   scanning: false, done: false, packages: 0, bytes: 0, tgzBytes: 0, diskBytes: null,
@@ -227,6 +230,7 @@ export function hasScanCache() {
 export function invalidateScan() {
   rawCache = null
   rawCacheAt = null
+  packagesCache = null // 清空包列表构建缓存
   clearPkgCache() // storage 目录切换 / 清理动作后废弃增量缓存，避免旧目录条目残留
 }
 
@@ -235,6 +239,7 @@ export function getScannedAt() {
 }
 
 // 构建包列表（统一状态计算 + 排序 + 忽略标记 + 来源筛选）
+// 缓存全量列表：rawCache/ignored/threshold 不变时复用，避免每次请求全量 map 7000+ 条
 export function buildPackages(keyword = '', origin = 'all') {
   const threshold = Number(getSetting('version_threshold', DEFAULT_VERSION_THRESHOLD))
   const ignoredRows = getIgnoredRows()
@@ -242,7 +247,11 @@ export function buildPackages(keyword = '', origin = 'all') {
   const ignoredAtMap = Object.fromEntries(ignoredRows.map(r => [r.pkg_name, (r.ignored_at || '').slice(0, 10)]))
   const raw = getRawPackages() || []
 
-  let list = raw.map(p => {
+  // 缓存 key：raw 长度 + ignored 内容 hash + threshold（任一变化即失效）
+  const ignoredHash = ignoredRows.map(r => `${r.pkg_name}:${r.ignored_at || ''}`).join('|')
+  const cacheKey = `${raw.length}_${ignoredHash}_${threshold}`
+  if (!packagesCache || packagesCache.key !== cacheKey) {
+    const list = raw.map(p => {
       let status
       if (p.status === 'broken') status = 'broken'
       else if (ignoredSet.has(p.name)) status = 'ignored'
@@ -263,6 +272,9 @@ export function buildPackages(keyword = '', origin = 'all') {
         latest: p.latest || null,
       }
     })
+    packagesCache = { key: cacheKey, list }
+  }
+  let list = packagesCache.list
 
   // 检索：不区分大小写子串，匹配包名（版本号匹配由前端本地完成，避免列表携带明细）
   const kw = keyword.trim().toLowerCase()
@@ -276,7 +288,7 @@ export function buildPackages(keyword = '', origin = 'all') {
 
   // 排序：预警置顶 → 正常 → 忽略 → 异常；同状态按版本数降序
   const rank = { warn: 0, ok: 1, ignored: 2, broken: 3 }
-  list.sort((a, b) => {
+  list = [...list].sort((a, b) => {
     if (rank[a.status] !== rank[b.status]) return rank[a.status] - rank[b.status]
     return b.versions - a.versions
   })

backend/server.js

@@ -20,6 +20,7 @@ process.env.UV_THREADPOOL_SIZE = process.env.UV_THREADPOOL_SIZE || '8'
 import express from 'express'
 import path from 'node:path'
 import fs from 'node:fs'
+import zlib from 'node:zlib'
 import { fileURLToPath } from 'node:url'
 import { resolveStorageDir } from './scanner.js'
 import { isDemoMode, scanState, runScanAsync } from './scan-manager.js'
@@ -40,6 +41,26 @@ const __dirname = path.dirname(fileURLToPath(import.meta.url))
 const app = express()
 app.use(express.json({ limit: '1mb' }))
 
+// gzip 压缩：大响应（如 /api/packages 7000+ 条）减少传输体积 60-80%，Node 内置 zlib 无需新依赖
+app.use((req, res, next) => {
+  const accept = req.headers['accept-encoding'] || ''
+  if (!accept.includes('gzip')) return next()
+  const originalJson = res.json.bind(res)
+  res.json = (data) => {
+    try {
+      const json = JSON.stringify(data)
+      if (json.length < 1024) return originalJson(data) // 小响应不压缩，避免开销
+      const compressed = zlib.gzipSync(json)
+      res.setHeader('Content-Encoding', 'gzip')
+      res.setHeader('Content-Type', 'application/json')
+      res.send(compressed)
+    } catch {
+      originalJson(data)
+    }
+  }
+  next()
+})
+
 const PORT = Number(process.env.PORT || 3000)
 
 // —— 路由装配：登录/登出/主题公开，其余 /api/* 需鉴权 ——