server/middlewares/cache.ts

   1 import * as express from 'express'
   2 import { Redis } from '../lib/redis'
   3 import { logger } from '../helpers/logger'
   4
   5 async function cacheRoute (req: express.Request, res: express.Response, next: express.NextFunction) {
   6   const cached = await Redis.Instance.getCachedRoute(req)
   7
   8   // Not cached
   9   if (!cached) {
  10     logger.debug('Not cached result for route %s.', req.originalUrl)
  11
  12     const sendSave = res.send.bind(res)
  13
  14     res.send = (body) => {
  15       if (res.statusCode >= 200 && res.statusCode < 400) {
  16         Redis.Instance.setCachedRoute(req, body, res.getHeader('content-type').toString(), res.statusCode)
  17              .catch(err => logger.error('Cannot cache route.', { err }))
  18       }
  19
  20       return sendSave(body)
  21     }
  22
  23     return next()
  24   }
  25
  26   if (cached.contentType) res.contentType(cached.contentType)
  27
  28   if (cached.statusCode) {
  29     const statusCode = parseInt(cached.statusCode, 10)
  30     if (!isNaN(statusCode)) res.status(statusCode)
  31   }
  32
  33   logger.debug('Use cached result for %s.', req.originalUrl)
  34   return res.send(cached.body).end()
  35 }
  36
  37 // ---------------------------------------------------------------------------
  38
  39 export {
  40   cacheRoute
  41 }