/opt/utils/cache.js

const Redis = require('ioredis')
const redis = new Redis({
  host: "xxx",
  port: '6379',
  // family: 4,
  password: 'xxx',
  // db: 0
})
exports.redis = redis

// 云函数入口文件
const cloud = require('wx-server-sdk')


cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV }) // 使用当前云环境
const TcbRouter = require('tcb-router')
const db = cloud.database()
const _ = db.command
const $ = db.command.aggregate


const cache = require('/opt/utils/cache.js') // 使用到了云函数的层管理
const dateUtil = require('/opt/utils/dateUtil.js') // 使用到了云函数的层管理


// 云函数入口函数
exports.main = async (event, context) => {


  const app = new TcbRouter({ event })
  // const { } = event
  const { OPENID, UNIONID } = cloud.getWXContext()
  const page = event.page ? Number(event.page) : 0;
  const pageSize = event.pageSize ? Number(event.pageSize) : 10;
  const skip = page * pageSize


  app.use(async (ctx, next) => {
    ctx.data = {}
    await next();
  });


  // 1.hot 热门问题(按回答人数)
  app.router('hot', async (ctx, next) => {
    try {
      const date = dateUtil.formatTime(new Date());//当前日期
      const cacheKey = `question:hot:${date}:${page}:${pageSize}`
      const cacheKeyExists = await cache.redis.exists(cacheKey)
      const cacheData = await cache.redis.lrange(cacheKey, 0, -1);


      if (cacheKeyExists) {
        if (cacheData.length == 1 && cacheData[0] == 'EMPTY') {
          // 缓存结果为空
          ctx.body = { code: 0, date, cacheKey, msg: '缓存结果空', data: [] }
        } else {
          // 有缓存
          let result = []
          for (let index = 0; index < cacheData.length; index++) {
            const element = JSON.parse(cacheData[index]);
            result.push(element)
          }
          ctx.body = { code: 0, date, cacheKey, msg: '缓存结果', data: result }
        }


      } else {
        // 从数据库查询数据
        const { data } = await db.collection('question').where({
          status: 'open',
          type: 'public'
        }).orderBy('total_answers', 'desc').skip(skip).limit(pageSize).field({
          create_time: 1,
          title: 1,
          total_answers: 1,
          total_viewers: 1,
          total_collectors: 1,
        }).get();


        if (data && data.length) {
          // 循环遍历存储到redis
          for (let index = 0; index < data.length; index++) {
            // 时间戳转日期
            data[index].create_time = dateUtil.toDate(data[index].create_time)
            const element = JSON.stringify(data[index]);
            await cache.redis.rpush(cacheKey, element);
            await cache.redis.expire(cacheKey, 60 * 60 * 24);//24小时过期
          }
        } else {
          // 数据为空时，设置缓存值为特殊字符串'EMPTY'
          await cache.redis.rpush(cacheKey, 'EMPTY', () => {
            cache.redis.expire(cacheKey, 60 * 60 * 24);//24小时过期
          })
        }

        ctx.body = { code: 0, date, cacheKey, msg: '数据库结果', data }
      }

    } catch (error) {
      ctx.body = { code: 1, msg: '获取热门问题失败', data: error }
    } finally {
      cache.redis.disconnect()
    }


  })
  // 2.latest 最新问题
  app.router('latest', async (ctx, next) => {
    try {
      const date = dateUtil.formatTime(new Date());//当前日期
      const cacheKey = `question:latest:${date}:${page}:${pageSize}`
      const cacheKeyExists = await cache.redis.exists(cacheKey)
      const cacheData = await cache.redis.lrange(cacheKey, 0, -1);


      if (cacheKeyExists) {
        if (cacheData.length == 1 && cacheData[0] == 'EMPTY') {
          // 缓存结果为空
          ctx.body = { code: 0, date, cacheKey, msg: '缓存结果空', data: [] }
        } else {
          // 有缓存
          let result = []
          for (let index = 0; index < cacheData.length; index++) {
            const element = JSON.parse(cacheData[index]);
            result.push(element)
          }
          ctx.body = { code: 0, date, cacheKey, msg: '缓存结果', data: result }
        }


      } else {
        // 从数据库查询数据
        const { data } = await db.collection('question').where({
          status: 'open',
          type: 'public'
        }).orderBy('create_time', 'desc').skip(skip).limit(pageSize).field({
          create_time: 1,
          title: 1,
          total_answers: 1,
          total_viewers: 1,
          total_collectors: 1,
        }).get();


        if (data && data.length) {
          // 循环遍历存储到redis
          for (let index = 0; index < data.length; index++) {
            // 时间戳转日期
            data[index].create_time = dateUtil.toDate(data[index].create_time)
            const element = JSON.stringify(data[index]);
            await cache.redis.rpush(cacheKey, element);
            await cache.redis.expire(cacheKey, 60 * 60 * 24);//24小时过期
          }
        } else {
          // 数据为空时，设置缓存值为特殊字符串'EMPTY'
          await cache.redis.rpush(cacheKey, 'EMPTY', () => {
            cache.redis.expire(cacheKey, 60 * 60 * 24);//24小时过期
          })
        }

        ctx.body = { code: 0, date, cacheKey, msg: '数据库结果', data }
      }

    } catch (error) {
      ctx.body = { code: 1, msg: '获取最新问题失败', data: error }
    } finally {
      cache.redis.disconnect()
    }
  })
 
  return app.serve();
}

如上图代码中，每个云函数中 调用cache.redis.disconnect()就能调用成功。

这样做的话会有性能上的影响吗？这样每次调用云函数都要重新连接redis吧？

还是有什么更好的办法忽略掉日志的错误吗？