perf(C6): 去重总数据列表顺序翻页改 keyset（前后端契约一起改）

背景：列表页 `ORDER BY id DESC LIMIT offset,size`，带筛选且选择性低时每页都要
对命中集做一次 filesort；深翻页 offset 也白扫索引。

改法（保持跳页/回退/改每页的原有行为）：
- 后端：page 接口新增可选 `last_id` 游标 —— 传了就 `id < lastId` + `LIMIT size`（无 offset），
  响应新增 `nextLastId`（本页最后一行 id）；不传仍是原 OFFSET 分页
- 管理前端：只有"下一页"用游标（上一页响应带回），跳页/改每页/筛选清空游标走 OFFSET
- 测试：新增 2 个后端契约测试（keyset 无 offset + nextLastId；无游标保持 LIMIT 30,15）

验证：mvn test 2897 全绿；admin-frontend-vue vue-tsc 通过 + 1619 测试全绿；
已部署 JAR 2b9ab774c60c3f5d802c9a2cee549008（双节点 health=200）与 admin-vue-20260914-112055。

admin-frontend-vue/src/pages/asin/DedupeRegistryPage.vue

@@ -43,6 +43,10 @@ const lockedGroupId = computed<number | null>(() => {
   return groups.value.length === 1 ? groups.value[0].id : null
 })
 const jumpPage = ref('')
+/** 顺序翻页游标：上一页响应给的 nextLastId；仅在"下一页"时使用，跳页/筛选时清空走 OFFSET。 */
+const pageCursor = ref<number | null>(null)
+/** 本次请求实际使用的游标（load 时决定） */
+let pendingCursor: number | null = null
 
 const totalPages = computed(() => Math.max(1, Math.ceil(total.value / pageSize.value)))
 
@@ -85,10 +89,15 @@ function stopExportWait(): void {
 async function load(): Promise<void> {
   loading.value = true
   try {
-    const result = await fetchDedupeTotalList(toDedupeListParams(filter, page.value, pageSize.value))
+    const result = await fetchDedupeTotalList(
+      toDedupeListParams(filter, page.value, pageSize.value, pendingCursor),
+    )
     rows.value = result.items
     total.value = result.total
     if (result.page >= 1) page.value = result.page
+    // 本页响应回传的游标留作"下一页"用；空页则清空（没有更多）
+    pageCursor.value = result.nextLastId ?? null
+    pendingCursor = null
   } catch (error) {
     ElMessage.error(error instanceof Error ? error.message : '去重数据加载失败')
   } finally {
@@ -98,11 +107,15 @@ async function load(): Promise<void> {
 
 function apply(): void {
   page.value = 1
+  pageCursor.value = null
+  pendingCursor = null
   void load()
 }
 
 function changePage(next: number): void {
   if (next < 1 || next > totalPages.value) return
+  // 只有"顺序下一页"用 keyset 游标（避免深分页 offset）；跳页/回退走 OFFSET，行为不变
+  pendingCursor = next === page.value + 1 ? pageCursor.value : null
   page.value = next
   void load()
 }
@@ -119,6 +132,8 @@ function goJump(): void {
 function changeSize(size: number) {
   pageSize.value = size
   page.value = 1
+  pageCursor.value = null
+  pendingCursor = null
   void load()
 }
 

admin-frontend-vue/src/pages/asin/asin-filter.ts

@@ -24,6 +24,8 @@ export interface AsinListParams {
   groupId?: number | null
   /** 国家代码（如 DE、UK）。 */
   country?: string
+  /** 顺序翻页游标（上一页返回的 nextLastId）：传了就忽略 page 偏移，走 keyset。 */
+  lastId?: number
 }
 
 /** 序列化到 Java 分页接口的查询参数（snake_case）。 */
@@ -36,6 +38,8 @@ export interface AsinPageQuery {
   end_date?: string
   group_id?: number
   country?: string
+  /** 顺序翻页游标（keyset）：传了就忽略 page 偏移。 */
+  last_id?: number
 }
 
 function finiteInt(value: unknown): number | null {
@@ -77,5 +81,6 @@ export function toAsinPageQuery(params: AsinListParams): AsinPageQuery {
   if (params.endDate) query.end_date = params.endDate
   if (params.groupId != null) query.group_id = params.groupId
   if (params.country) query.country = params.country
+  if (typeof params.lastId === 'number' && params.lastId > 0) query.last_id = params.lastId
   return query
 }

admin-frontend-vue/src/pages/asin/dedupe-total-filter.ts

@@ -30,8 +30,10 @@ export function toDedupeListParams(
   state: DedupeTotalFilterState,
   page: number,
   pageSize: number,
+  lastId?: number | null,
 ): AsinListParams {
   const params: AsinListParams = { page, pageSize }
+  if (typeof lastId === 'number' && lastId > 0) params.lastId = lastId
   const keyword = (state.keyword || '').trim()
   const username = (state.username || '').trim()
   const country = (state.country || '').trim()

admin-frontend-vue/src/pages/asin/dedupe-total-model.ts

@@ -18,6 +18,8 @@ export interface DedupeTotalPageResult {
   total: number
   page: number
   pageSize: number
+  /** 顺序翻页游标：本页最后一行 id；下一页回传它即可走 keyset。 */
+  nextLastId?: number
 }
 
 export function emptyDedupeTotalPage(): DedupeTotalPageResult {
@@ -65,6 +67,8 @@ export function parseDedupeTotalPage(payload: unknown): DedupeTotalPageResult {
   }
   if (typeof record.total === 'number') out.total = Math.floor(record.total)
   if (typeof record.page === 'number' && record.page >= 1) out.page = Math.floor(record.page)
+  const rawNextLastId = record.nextLastId ?? record.next_last_id
+  if (typeof rawNextLastId === 'number' && rawNextLastId > 0) out.nextLastId = Math.floor(rawNextLastId)
   const rawSize = record.pageSize ?? record.page_size
   if (typeof rawSize === 'number' && rawSize >= 1) out.pageSize = Math.floor(rawSize)
   return out

backend-java/src/main/java/com/nanri/aiimage/modules/dedupe/controller/DedupeTotalDataController.java

@@ -88,10 +88,12 @@ public class DedupeTotalDataController {
             @RequestParam(name = "end_date", required = false) @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate endDate,
             @Parameter(description = "分组 ID") @RequestParam(name = "group_id", required = false) Long groupId,
             @Parameter(description = "国家代码（如 DE、UK）") @RequestParam(name = "country", required = false) String country,
+            @Parameter(description = "顺序翻页游标（上一页返回的 nextLastId；传了就忽略 page 偏移）")
+            @RequestParam(name = "last_id", required = false) Long lastId,
             HttpServletRequest request) {
         RequestOperator operator = requireDedupeTotalDataAccess(request);
         return ApiResponse.success(dedupeTotalDataService.page(
-                page, pageSize, keyword, username, startDate, endDate, groupId, country, operator.id()));
+                page, pageSize, keyword, username, startDate, endDate, groupId, country, lastId, operator.id()));
     }
 
     @GetMapping("/export")

backend-java/src/main/java/com/nanri/aiimage/modules/dedupe/model/vo/DedupeTotalDataPageVo.java

@@ -20,4 +20,9 @@ public class DedupeTotalDataPageVo {
 
     @Schema(description = "每页数量")
     private Long pageSize;
+    /**
+     * 顺序翻页游标（2026-09 审查 C6）：本页最后一行的 id；下一页把它回传为 last_id
+     * 即可走 keyset（索引顺序扫描 + LIMIT），避免深分页的 offset 代价。跳页仍用 page。
+     */
+    private Long nextLastId;
 }

backend-java/src/main/java/com/nanri/aiimage/modules/dedupe/service/DedupeTotalDataService.java

@@ -156,6 +156,16 @@ public class DedupeTotalDataService {
 
     public DedupeTotalDataPageVo page(long page, long pageSize, String keyword, String username,
                                       LocalDate startDate, LocalDate endDate, Long groupId, String country, Long operatorId) {
+        return page(page, pageSize, keyword, username, startDate, endDate, groupId, country, null, operatorId);
+    }
+
+    /**
+     * @param lastId keyset 游标（上一页返回的 nextLastId）；非空时忽略 page 偏移，
+     *               直接按 id 倒序取"比它小"的一页，避免深分页 offset 扫索引的代价
+     */
+    public DedupeTotalDataPageVo page(long page, long pageSize, String keyword, String username,
+                                      LocalDate startDate, LocalDate endDate, Long groupId, String country,
+                                      Long lastId, Long operatorId) {
         if (startDate != null && endDate != null && startDate.isAfter(endDate)) {
             throw new BusinessException("开始日期不能晚于结束日期");
         }
@@ -181,8 +191,14 @@ public class DedupeTotalDataService {
                 .orderByDesc(DedupeTotalDataEntity::getId);
         applyGroupScope(query, scope, groupId);
         Long total = dedupeTotalDataMapper.selectCount(query);
+        boolean keyset = lastId != null && lastId > 0;
+        if (keyset) {
+            query.lt(DedupeTotalDataEntity::getId, lastId);
+        }
         List<DedupeTotalDataEntity> rows = dedupeTotalDataMapper.selectList(
-                query.last("LIMIT " + ((safePage - 1) * safePageSize) + ", " + safePageSize));
+                keyset
+                        ? query.last("LIMIT " + safePageSize)
+                        : query.last("LIMIT " + ((safePage - 1) * safePageSize) + ", " + safePageSize));
         Map<Long, String> groupNames = loadGroupNames(rows);
         List<DedupeTotalDataItemVo> items = rows.stream()
                 .map(row -> toItemVo(row, row.getGroupId() == null
@@ -194,6 +210,8 @@ public class DedupeTotalDataService {
         vo.setTotal(total);
         vo.setPage(safePage);
         vo.setPageSize(safePageSize);
+        // 顺序翻页游标：本页最后一行的 id（空页给 null，前端据此停止换页）
+        vo.setNextLastId(items.isEmpty() ? null : items.get(items.size() - 1).getId());
         return vo;
     }
 

backend-java/src/test/java/com/nanri/aiimage/modules/dedupe/service/DedupeTotalDataServiceTest.java

@@ -43,6 +43,7 @@ import java.util.Set;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -632,4 +633,53 @@ class DedupeTotalDataServiceTest {
                     output.toByteArray());
         }
     }
+    @Test
+    void pageWithLastIdUsesKeysetAndReturnsNextCursor() {
+        // 2026-09 审查 C6：顺序翻页走 keyset（id < lastId + LIMIT n，无 offset）
+        TableInfoHelper.initTableInfo(
+                new MapperBuilderAssistant(new MybatisConfiguration(), ""),
+                DedupeTotalDataEntity.class);
+        when(adminUserMapper.selectById(1L)).thenReturn(user(1L, "super_admin", "root"));
+        when(dedupeTotalDataMapper.selectCount(any())).thenReturn(0L);
+        List<DedupeTotalDataEntity> rows = new ArrayList<>();
+        DedupeTotalDataEntity first = new DedupeTotalDataEntity();
+        first.setId(900L);
+        first.setDataValue("B0ROW900");
+        DedupeTotalDataEntity second = new DedupeTotalDataEntity();
+        second.setId(880L);
+        second.setDataValue("B0ROW880");
+        rows.add(first);
+        rows.add(second);
+        when(dedupeTotalDataMapper.selectList(any())).thenReturn(rows);
+
+        DedupeTotalDataPageVo vo = service.page(3, 15, "", "", null, null, null, null, 1000L, 1L);
+
+        ArgumentCaptor<LambdaQueryWrapper<DedupeTotalDataEntity>> queryCaptor =
+                ArgumentCaptor.forClass((Class) LambdaQueryWrapper.class);
+        verify(dedupeTotalDataMapper).selectList(queryCaptor.capture());
+        LambdaQueryWrapper<DedupeTotalDataEntity> query = queryCaptor.getValue();
+        assertTrue(query.getSqlSegment().contains("id <"), "keyset 条件应为主键范围: " + query.getSqlSegment());
+        assertTrue(query.getCustomSqlSegment().contains("LIMIT 15"), "keyset 分页不带 offset: " + query.getCustomSqlSegment());
+        assertFalse(query.getCustomSqlSegment().contains(","), "keyset 不应出现 offset 逗号: " + query.getCustomSqlSegment());
+        assertEquals(880L, vo.getNextLastId(), "nextLastId 取本页最后一行 id");
+    }
+
+    @Test
+    void pageWithoutLastIdKeepsOffsetPaging() {
+        TableInfoHelper.initTableInfo(
+                new MapperBuilderAssistant(new MybatisConfiguration(), ""),
+                DedupeTotalDataEntity.class);
+        when(adminUserMapper.selectById(1L)).thenReturn(user(1L, "super_admin", "root"));
+        when(dedupeTotalDataMapper.selectCount(any())).thenReturn(0L);
+        when(dedupeTotalDataMapper.selectList(any())).thenReturn(new ArrayList<>());
+
+        DedupeTotalDataPageVo vo = service.page(3, 15, "", "", null, null, null, null, 1L);
+
+        ArgumentCaptor<LambdaQueryWrapper<DedupeTotalDataEntity>> queryCaptor =
+                ArgumentCaptor.forClass((Class) LambdaQueryWrapper.class);
+        verify(dedupeTotalDataMapper).selectList(queryCaptor.capture());
+        assertTrue(queryCaptor.getValue().getCustomSqlSegment().contains("LIMIT 30, 15"),
+                "无游标时保持原有 offset 分页: " + queryCaptor.getValue().getCustomSqlSegment());
+        assertNull(vo.getNextLastId(), "空页无游标");
+    }
 }