import * as express from 'express'
+import * as AsyncLock from 'async-lock'
+import { parseDuration } from '../helpers/core-utils'
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)
+const lock = new AsyncLock({ timeout: 5000 })
- // Not cached
- if (!cached) {
- logger.debug('Not cached result for route %s.', req.originalUrl)
+function cacheRoute (lifetimeArg: string | number) {
+ return async function (req: express.Request, res: express.Response, next: express.NextFunction) {
+ const redisKey = Redis.Instance.generateCachedRouteKey(req)
- const sendSave = res.send.bind(res)
+ try {
+ await lock.acquire(redisKey, async (done) => {
+ const cached = await Redis.Instance.getCachedRoute(req)
- 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 }))
- }
+ // Not cached
+ if (!cached) {
+ logger.debug('No cached results for route %s.', req.originalUrl)
- return sendSave(body)
- }
+ const sendSave = res.send.bind(res)
- return next()
- }
+ res.send = (body) => {
+ if (res.statusCode >= 200 && res.statusCode < 400) {
+ const contentType = res.get('content-type')
+ const lifetime = parseDuration(lifetimeArg)
- if (cached.contentType) res.contentType(cached.contentType)
+ Redis.Instance.setCachedRoute(req, body, lifetime, contentType, res.statusCode)
+ .then(() => done())
+ .catch(err => {
+ logger.error('Cannot cache route.', { err })
+ return done(err)
+ })
+ } else {
+ done()
+ }
- if (cached.statusCode) {
- const statusCode = parseInt(cached.statusCode, 10)
- if (!isNaN(statusCode)) res.status(statusCode)
- }
+ return sendSave(body)
+ }
+
+ return next()
+ }
+
+ if (cached.contentType) res.set('content-type', cached.contentType)
- logger.debug('Use cached result for %s.', req.originalUrl)
- return res.send(cached.body).end()
+ if (cached.statusCode) {
+ const statusCode = parseInt(cached.statusCode, 10)
+ if (!isNaN(statusCode)) res.status(statusCode)
+ }
+
+ logger.debug('Use cached result for %s.', req.originalUrl)
+ res.send(cached.body).end()
+
+ return done()
+ })
+ } catch (err) {
+ logger.error('Cannot serve cached route.', { err })
+ return next()
+ }
+ }
}
// ---------------------------------------------------------------------------