feat:抢单大厅数据排列优化

apps/backend/src/repositories/realtime-event-repo.ts

@@ -62,10 +62,13 @@ export async function createRealtimeEvent(input: {
 export async function listRealtimeEventsAfter(eventId: number, limit = 500) {
   const result = await query<RealtimeEventRow>(
     `
-      SELECT * FROM realtime_events
-      WHERE id > $1
+      SELECT * FROM (
+        SELECT * FROM realtime_events
+        WHERE id > $1
+        ORDER BY id DESC
+        LIMIT $2
+      ) replay_window
       ORDER BY id ASC
-      LIMIT $2
     `,
     [Math.max(0, Number(eventId) || 0), Math.min(500, Math.max(1, Number(limit) || 500))],
   )

apps/backend/src/services/realtime/realtime-event-service.ts

@@ -85,6 +85,24 @@ let nextSubscriberId = 1
 let heartbeatTimer: NodeJS.Timeout | null = null
 let publishQueue: Promise<void> = Promise.resolve()
 
+/**
+ * 单次补发的事件上限，与 realtime_events 表保留的条数一致
+ * （见 realtime-event-repo 的清理策略：只保留最近 500 条）。
+ */
+export const REALTIME_REPLAY_EVENT_LIMIT = 500
+
+/**
+ * 是否应该补发历史事件。
+ *
+ * 只有断线重连带上了 Last-Event-ID（游标 > 0）才补发。新连接（游标 = 0）**不补发**：
+ * 补发的每一条都携带「事件发生那一刻」的工单快照，直接打进刚由列表接口加载好的缓存，
+ * 会把已涨价/已拼满的订单覆盖回旧值（表现为「进大厅显示旧单价旧进度，点一次刷新才对」）。
+ */
+export function shouldReplayRealtimeEvents(lastEventId: number): boolean {
+  const normalized = Number(lastEventId)
+  return Number.isFinite(normalized) && normalized > 0
+}
+
 /** 建立后台实时事件流，事件快照用于前端定点更新缓存。 */
 export function openAdminRealtimeStream(response: Response, lastEventId = 0) {
   return openRealtimeStream(response, null, lastEventId)
@@ -532,7 +550,10 @@ function openRealtimeStream(response: Response, workerId: number | null, lastEve
     connectedAt: new Date().toISOString(),
     lastEventId: Math.max(0, Number(lastEventId) || 0),
   })
-  void replayEvents(subscriber, Math.max(0, Number(lastEventId) || 0))
+  // 新连接不补发历史事件，只有断线重连（带游标）才回放缺失的增量。
+  if (shouldReplayRealtimeEvents(lastEventId)) {
+    void replayEvents(subscriber, Number(lastEventId))
+  }
   ensureHeartbeat()
 
   response.on('close', () => {
@@ -542,7 +563,16 @@ function openRealtimeStream(response: Response, workerId: number | null, lastEve
 }
 
 async function replayEvents(subscriber: RealtimeSubscriber, lastEventId: number) {
-  const events = await listRealtimeEventsAfter(lastEventId)
+  const events = await listRealtimeEventsAfter(lastEventId, REALTIME_REPLAY_EVENT_LIMIT)
+  // 补发窗口被拿满 = 更早的事件已经从事件表里滚掉（断线太久）。
+  // 这时逐条套用旧快照只会把列表写回旧值，直接让客户端整体重拉一次。
+  if (events.length >= REALTIME_REPLAY_EVENT_LIMIT) {
+    writeEvent(subscriber, 'resync', {
+      headEventId: Number(events[events.length - 1]?.id || 0),
+      reason: 'replay_window_overflow',
+    })
+    return
+  }
   for (const row of events) {
     const event = mapStoredEvent(row)
     if (event.eventId <= lastEventId || !isEventVisibleToSubscriber(event, subscriber)) continue

apps/backend/src/services/realtime/realtime-replay.test.ts

@@ -1,4 +1,5 @@
 import assert from 'node:assert/strict'
+import fs from 'node:fs'
 import test from 'node:test'
 
 import { shouldReplayRealtimeEvents } from './realtime-event-service.js'
@@ -20,3 +21,36 @@ test('断线重连（带 Last-Event-ID）才补发事件', () => {
   assert.equal(shouldReplayRealtimeEvents(1), true)
   assert.equal(shouldReplayRealtimeEvents(3993659), true)
 })
+
+test('补发窗口取最新的一段，而不是最旧的一段', () => {
+  const source = fs.readFileSync(
+    new URL('../../repositories/realtime-event-repo.ts', import.meta.url),
+    'utf8',
+  )
+  const block = source.slice(
+    source.indexOf('export async function listRealtimeEventsAfter('),
+    source.indexOf('\n}', source.indexOf('export async function listRealtimeEventsAfter(')),
+  )
+  assert.ok(block.length > 0, 'listRealtimeEventsAfter 片段必须存在')
+  assert.ok(
+    /ORDER BY id DESC\s+LIMIT \$2\s+\)\s*replay_window\s+ORDER BY id ASC/s.test(block),
+    '补发必须「内层 id DESC 取最新 N 条、外层 id ASC 回放」；否则断线久了窗口会停在旧事件上',
+  )
+})
+
+test('补发窗口溢出时改为让客户端整体重拉', () => {
+  const source = fs.readFileSync(new URL('./realtime-event-service.ts', import.meta.url), 'utf8')
+  const replayBlock = source.slice(
+    source.indexOf('async function replayEvents('),
+    source.indexOf('function mapStoredEvent('),
+  )
+  assert.ok(replayBlock.length > 0, 'replayEvents 片段必须存在')
+  assert.ok(
+    replayBlock.includes('events.length >= REALTIME_REPLAY_EVENT_LIMIT'),
+    '补发窗口被拿满时必须判定为溢出，不能继续逐条套用旧快照',
+  )
+  assert.ok(
+    replayBlock.includes("'resync'"),
+    '溢出时要给客户端发 resync，让列表整体重拉（接口才是权威数据源）',
+  )
+})