feat: 添加分页功能和缓存管理，优化问答记录展示

server/api/cache/clear.post.ts

@@ -1,27 +1,22 @@
-// server/api/cache/clear.post.ts - 清空答题缓存接口
-import { answerCache } from "~~/server/utils/cache";
-import { serverEnv } from "~~/server/utils/env";
+// server/api/cache/clear.post.ts - 清空当前用户 DB 缓存接口
+import { prisma } from "~~/server/utils/db";
 import { createApiLogger } from "~~/server/utils/logging";
 
 /**
- * 清空内存缓存
+ * 清缓存：将当前用户的 cacheClearedAt 更新为当前时间
  *
- * 这是一个管理类接口，必须携带有效 session cookie（由 api-auth middleware 统一鉴权）
- * 清理的是当前 Nuxt 进程内缓存；多实例部署时，每个实例都有自己的内存缓存
+ * 之后查 DB 缓存时只命中该时间之后写入的记录，历史记录全部保留。
+ * 必须携带有效 session cookie（由 api-auth middleware 统一鉴权）
  */
-export default defineEventHandler((event) => {
+export default defineEventHandler(async (event) => {
   const logger = createApiLogger(event, "api.cache.clear");
+  const userId = event.context.auth!.user.id;
 
-  // 缓存被关闭时不报错，只明确告诉调用方当前没有缓存可清
-  if (!serverEnv.enableCache || !answerCache) {
-    return {
-      success: false,
-      message: "缓存未启用"
-    };
-  }
+  await prisma.user.update({
+    where: { id: userId },
+    data: { cacheClearedAt: new Date() }
+  });
 
-  // 清空当前进程内缓存，DB 记录不受影响
-  answerCache.clear();
   logger.info("finish_success");
 
   return {

server/api/health.get.ts

@@ -6,14 +6,13 @@ import { SERVICE_VERSION } from "~~/server/utils/runtimeState";
  * 健康检查不需要鉴权
  *
  * 这个接口用于部署平台、Docker healthcheck 或人工确认服务是否启动；
- * 返回模型名和缓存开关，但不返回 API Key、baseURL 或其他敏感配置
+ * 返回模型名，但不返回 API Key、baseURL 或其他敏感配置
  */
 export default defineEventHandler(() => {
   return {
     status: "ok",
     message: "AI题库服务运行正常",
     version: SERVICE_VERSION,
-    cache_enabled: serverEnv.enableCache,
     model: serverEnv.openAiModel
   };
 });

server/api/records.get.ts

@@ -18,9 +18,9 @@ export default defineEventHandler(async (event) => {
   const query = getQuery(event);
   const rawPage = Number.parseInt(query.page?.toString() || "1", 10);
   const rawSize = Number.parseInt(query.size?.toString() || "10", 10);
-  const size = Number.isFinite(rawSize)
-    ? Math.min(Math.max(rawSize, 1), 100)
-    : 10;
+  // size 只允许 10 / 50 / 100；传入其他值（含超出上限）一律退回 10
+  const ALLOWED_SIZES = new Set([10, 50, 100]);
+  const size = ALLOWED_SIZES.has(rawSize) ? rawSize : 10;
   const page = Number.isFinite(rawPage) ? Math.max(rawPage, 1) : 1;
 
   const { records, total } = await getQaRecords(event.context.auth!.user.id, {

server/api/search.ts

@@ -1,4 +1,6 @@
 // server/api/search.ts - OCS AnswererWrapper 兼容搜索接口
+import { createHash } from "node:crypto";
+
 import {
   getQuery,
   type H3Event,
@@ -16,11 +18,10 @@ import {
   type SearchParams
 } from "~~/server/utils/answer";
 import { getAuthSession } from "~~/server/utils/auth";
-import { answerCache } from "~~/server/utils/cache";
 import { prisma } from "~~/server/utils/db";
 import { createApiLogger, toSafeLogError } from "~~/server/utils/logging";
 import { askAnswerStream } from "~~/server/utils/openai";
-import { addQaRecord } from "~~/server/utils/runtimeState";
+import { addQaRecord, lookupCachedAnswer } from "~~/server/utils/runtimeState";
 
 /**
  * 把 query/body/form 中的值统一转成字符串
@@ -138,17 +139,25 @@ export default defineEventHandler(async (event) => {
 
     // 鉴权：优先 session（浏览器登录），无 session 则用 body.token 查 apiToken
     // OCS 油猴脚本跨域无法携带 cookie，需在 body 中传入用户自己的 apiToken
+    // 同时取出 cacheClearedAt，用于 DB 缓存过滤
     let userId: string | null = null;
+    let cacheClearedAt: Date | null = null;
 
     const session = await getAuthSession(event);
     if (session) {
       userId = session.user.id;
+      const userData = await prisma.user.findUnique({
+        where: { id: userId },
+        select: { cacheClearedAt: true }
+      });
+      cacheClearedAt = userData?.cacheClearedAt ?? null;
     } else if (params.token) {
       const user = await prisma.user.findUnique({
         where: { apiToken: params.token },
-        select: { id: true }
+        select: { id: true, cacheClearedAt: true }
       });
       userId = user?.id ?? null;
+      cacheClearedAt = user?.cacheClearedAt ?? null;
     }
 
     if (!userId) {
@@ -167,12 +176,12 @@ export default defineEventHandler(async (event) => {
       return createOcsErrorResponse("未提供问题内容");
     }
 
-    // 缓存 key 包含题目、题型和选项；同题不同选项不能共用答案
-    const cachedAnswer = answerCache?.get(
-      params.title,
-      params.type,
-      params.options
-    );
+    // 计算缓存 key：题目+题型+选项的 MD5；同题不同选项不能共用答案
+    const hash = createHash("md5")
+      .update(`${params.title}|${params.type}|${params.options}`, "utf8")
+      .digest("hex");
+
+    const cachedAnswer = await lookupCachedAnswer(userId, hash, cacheClearedAt);
 
     if (cachedAnswer) {
       logger.info("cache_hit");
@@ -191,19 +200,14 @@ export default defineEventHandler(async (event) => {
     });
     const processedAnswer = extractAnswer(streamResult.answer, params.type);
 
-    // 先缓存再记录；这两步失败风险很低，且都是内存操作，不会阻塞主链路
-    answerCache?.set(
-      params.title,
-      processedAnswer,
-      params.type,
-      params.options
-    );
+    // 写入 DB 记录（带 hash）；记录本身即为后续缓存查询的来源
     await addQaRecord({
       userId,
       question: params.title,
       type: params.type,
       options: params.options,
-      answer: processedAnswer
+      answer: processedAnswer,
+      hash
     });
 
     logger.info("finish_success", {

server/api/stats.get.ts

@@ -1,16 +1,23 @@
 // server/api/stats.get.ts - 服务运行统计接口
+import { prisma } from "~~/server/utils/db";
 import { createApiLogger } from "~~/server/utils/logging";
 import { getRuntimeStats } from "~~/server/utils/runtimeState";
 
 /**
  * 运行统计接口
  *
- * 统计信息包含 uptime、模型名、缓存数量、最近问答记录数量
+ * 返回进程 uptime、模型名以及当前用户的问答记录总数
  * 必须携带有效 session cookie（由 api-auth middleware 统一鉴权）
  */
-export default defineEventHandler((event) => {
+export default defineEventHandler(async (event) => {
   const logger = createApiLogger(event, "api.stats");
-  // getRuntimeStats 会实时清理过期缓存，再返回有效缓存数量
+  const userId = event.context.auth!.user.id;
+
+  const [runtimeStats, qa_records_count] = await Promise.all([
+    Promise.resolve(getRuntimeStats()),
+    prisma.qaRecord.count({ where: { userId } })
+  ]);
+
   logger.info("finish_success");
-  return getRuntimeStats();
+  return { ...runtimeStats, qa_records_count };
 });

server/utils/cache.ts

@@ -1,100 +0,0 @@
-// server/utils/cache.ts - 简单内存缓存，按题目、题型和选项生成缓存键
-import { createHash } from "node:crypto";
-
-import { serverEnv } from "~~/server/utils/env";
-
-/**
- * 旧 Python 服务使用进程内字典缓存答案
- *
- * Nuxt 版保持同样的“内存缓存”语义：服务重启后缓存清空，不跨实例共享；
- * 这对个人题库服务足够简单，也避免为了缓存引入数据库或 Redis
- */
-export class SimpleCache {
-  /** Map key 是题目、题型和选项计算出的 md5；value 保存写入时间和答案 */
-  private readonly cache = new Map<
-    string,
-    {
-      timestamp: number;
-      value: string;
-    }
-  >();
-
-  constructor(private readonly expirationSeconds: number) {}
-
-  /**
-   * 根据题目、题型和选项生成缓存键
-   *
-   * 同一道题如果选项不同，不能复用旧答案，所以三个字段都参与计算
-   */
-  private generateKey(question: string, questionType = "", options = "") {
-    return createHash("md5")
-      .update(`${question}|${questionType}|${options}`, "utf8")
-      .digest("hex");
-  }
-
-  /**
-   * 读取缓存答案
-   *
-   * 命中过期项时会顺手删除，避免长时间运行后堆积无效缓存
-   */
-  get(question: string, questionType = "", options = "") {
-    const key = this.generateKey(question, questionType, options);
-    const item = this.cache.get(key);
-    if (!item) return undefined;
-
-    if (Date.now() - item.timestamp < this.expirationSeconds * 1000) {
-      return item.value;
-    }
-
-    this.cache.delete(key);
-    return undefined;
-  }
-
-  /** 写入答案缓存，时间戳使用当前进程时间即可 */
-  set(question: string, answer: string, questionType = "", options = "") {
-    const key = this.generateKey(question, questionType, options);
-    this.cache.set(key, {
-      timestamp: Date.now(),
-      value: answer
-    });
-  }
-
-  /** 清空全部缓存，对应 `/api/cache/clear` */
-  clear() {
-    this.cache.clear();
-  }
-
-  /**
-   * 批量移除过期项
-   *
-   * 目前在统计缓存大小时调用，避免 stats 返回已经过期的数量
-   */
-  removeExpired() {
-    const now = Date.now();
-    let removedCount = 0;
-
-    for (const [key, item] of this.cache.entries()) {
-      if (now - item.timestamp >= this.expirationSeconds * 1000) {
-        this.cache.delete(key);
-        removedCount += 1;
-      }
-    }
-
-    return removedCount;
-  }
-
-  /** 获取当前有效缓存数量 */
-  size() {
-    this.removeExpired();
-    return this.cache.size;
-  }
-}
-
-/**
- * 全局答案缓存实例
- *
- * 如果 `ENABLE_CACHE=false`，导出 undefined，调用处用可选链即可保持逻辑简洁
- */
-export const answerCache = serverEnv.enableCache
-  ? new SimpleCache(serverEnv.cacheExpiration)
-  : undefined;

server/utils/env.ts

@@ -73,10 +73,6 @@ export const serverEnv = {
   maxTokens: readInteger("MAX_TOKENS", 500),
   /** 模型采样温度，越低越稳定 */
   temperature: readNumber("TEMPERATURE", 0.7),
-  /** 是否启用内存缓存 */
-  enableCache: readBoolean("ENABLE_CACHE", true),
-  /** 缓存过期时间，单位秒 */
-  cacheExpiration: readInteger("CACHE_EXPIRATION", 86_400),
   /** 预留日志级别配置，目前日志工具只负责安全输出 */
   logLevel: readString("LOG_LEVEL", "INFO"),
   /** 单行 SSE data 的最大字节数，用于防止异常流无限堆内存 */

server/utils/runtimeState.ts

@@ -1,5 +1,4 @@
 // server/utils/runtimeState.ts - 服务启动时间内存状态 + 问答记录 DB 读写
-import { answerCache } from "~~/server/utils/cache";
 import { prisma } from "~~/server/utils/db";
 import { serverEnv } from "~~/server/utils/env";
 
@@ -29,6 +28,7 @@ export const addQaRecord = async (record: {
   type: string;
   options: string;
   answer: string;
+  hash: string;
 }) => {
   await prisma.qaRecord.create({
     data: {
@@ -36,11 +36,34 @@ export const addQaRecord = async (record: {
       question: record.question,
       type: record.type,
       options: record.options || null,
-      answer: record.answer || null
+      answer: record.answer || null,
+      hash: record.hash
     }
   });
 };
 
+/**
+ * 按用户 + hash 查找 DB 缓存答案
+ *
+ * 只返回 cacheClearedAt 之后写入的记录；未存入时间或 hash 为 null 的老记录不会命中
+ */
+export const lookupCachedAnswer = async (
+  userId: string,
+  hash: string,
+  cacheClearedAt: Date | null
+): Promise<string | null> => {
+  const record = await prisma.qaRecord.findFirst({
+    where: {
+      userId,
+      hash,
+      ...(cacheClearedAt ? { createdAt: { gt: cacheClearedAt } } : {})
+    },
+    orderBy: { createdAt: "desc" },
+    select: { answer: true }
+  });
+  return record?.answer ?? null;
+};
+
 /**
  * 从数据库分页读取指定用户的问答记录，按创建时间倒序
  */
@@ -76,13 +99,11 @@ export const getQaRecords = async (
   }));
   return { records, total };
 };
-/** 生成 `/api/stats` 响应，实时计算 uptime 和有效缓存数量 */
+/** 生成 `/api/stats` 的基础运行时信息，不包含用户相关数据 */
 export const getRuntimeStats = () => {
   return {
     version: SERVICE_VERSION,
     uptime: (Date.now() - startTime) / 1000,
-    model: serverEnv.openAiModel,
-    cache_enabled: serverEnv.enableCache,
-    cache_size: answerCache?.size() ?? 0
+    model: serverEnv.openAiModel
   };
 };