redis.js

import Redis from 'ioredis'
import { logger, timeSinceStartup } from './logger.js'
import Queue from 'bull'
import { registerLatestVersionListener, updateVersionProcessor } from './version.js'

const commonQueueOptions = { enableReadyCheck: false, maxRetriesPerRequest: null }

const createClient = (type, options = {}) => {
  if (!isEnabled()) {
    return new Proxy({
      getBuffer () {},
      get () {},
      set () {},
      del () {},
      flushdb () { return {} },
      status: '',
      duplicate () { return new Redis() },
      publish () {},
      subscribe () {},
      on () {},
      quit () { }
    }, {
      get () {
        throw new Error('Redis is disabled. Check for redis.isEnabled()')
      }
    })
  }

  const client = new Redis({
    host: process.env.REDIS_HOST,
    port: Number(process.env.REDIS_PORT),
    db: Number(process.env.REDIS_DB),
    password: process.env.REDIS_PASSWORD,
    ...options
  })
  client.on('ready', () => logger.info(`[Redis] Connected ${type} to redis on ${process.env.REDIS_HOST}. Time since startup: ${timeSinceStartup()}s`))
  client.on('error', (err) => logger.error(`[Redis] Connect error: ${err}`))

  return client
}

export async function isReady () {
  return new Promise(resolve => {
    if (!isEnabled()) return resolve(true)
    client.on('ready', () => resolve(true))
    client.on('error', () => resolve(false))
  }).catch(() => false)
}

export const client = createClient('common client')
export const pubClient = createClient('pub client')
export const subClient = createClient('sub client', commonQueueOptions)

/*
 * Bull specific things are below
 */

if (isEnabled()) {
  client.on('ready', () => {
    const updateVersionQueue = getQueue('update-version')
    try {
      updateVersionQueue.process(updateVersionProcessor)
      logger.debug('[Redis] Register version update processor.')
    } catch (err) {
      logger.debug('[Redis] Update version processor is already registered.')
    }
    updateVersionQueue.add({}, {
      jobId: 'update-version-job',
      repeat: { every: Number(process.env.CACHE_TTL) },
      removeOnComplete: 10,
      removeOnFail: 10,
      timeout: 10000
    })
  })

  registerLatestVersionListener(subClient)
} else {
  setTimeout(() => {
    setInterval(updateVersionProcessor, Number(process.env.CACHE_TTL))
  })
}

/*
 * queue specific code
 */

const queues = {}

export function getQueue (name) {
  if (queues[name]) return queues[name]
  // @ts-ignore
  return (queues[name] = new Queue(name, {
    prefix: process.env.REDIS_PREFIX,
    createClient: function (type) {
      switch (type) {
        case 'client':
          return client.duplicate()
        case 'subscriber':
          return subClient.duplicate()
        default:
          return client.duplicate(commonQueueOptions)
      }
    }
  }))
}

export function getQueues () {
  return Object.values(queues)
}

export async function closeQueue (name) {
  if (!queues[name]) throw new Error(`No such queue "${name}" to close.`)
  const queue = queues[name]
  delete queues[name]
  const jobs = await queue.getRepeatableJobs()
  for (const job of jobs) {
    queue.removeRepeatableByKey(job.key)
  }
  return queue.close()
}

export function isEnabled () {
  return !!process.env.REDIS_HOST
}