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