Add redis cache to feed route

server/middlewares/cache.ts

@@ -0,0 +1,41 @@
+import * as express from 'express'
+import { Redis } from '../lib/redis'
+import { logger } from '../helpers/logger'
+
+async function cacheRoute (req: express.Request, res: express.Response, next: express.NextFunction) {
+  const cached = await Redis.Instance.getCachedRoute(req)
+
+  // Not cached
+  if (!cached) {
+    logger.debug('Not cached result for route %s.', req.originalUrl)
+
+    const sendSave = res.send.bind(res)
+
+    res.send = (body) => {
+      if (res.statusCode >= 200 && res.statusCode < 400) {
+        Redis.Instance.setCachedRoute(req, body, res.getHeader('content-type').toString(), res.statusCode)
+             .catch(err => logger.error('Cannot cache route.', { err }))
+      }
+
+      return sendSave(body)
+    }
+
+    return next()
+  }
+
+  if (cached.contentType) res.contentType(cached.contentType)
+
+  if (cached.statusCode) {
+    const statusCode = parseInt(cached.statusCode, 10)
+    if (!isNaN(statusCode)) res.status(statusCode)
+  }
+
+  logger.debug('Use cached result for %s.', req.originalUrl)
+  return res.send(cached.body).end()
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  cacheRoute
+}