gistfile1.txt

                   
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 28Mb 
Memory Usage: 25Mb 
Memory Usage: 23Mb 
Memory Usage: 36Mb 
Memory Usage: 33Mb 
Memory Usage: 31Mb 
Memory Usage: 28Mb 
Memory Usage: 39Mb 
Memory Usage: 36Mb 
Memory Usage: 34Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 25Mb 
Memory Usage: 34Mb 
Memory Usage: 20Mb 
Memory Usage: 20Mb 
Memory Usage: 21Mb 
Memory Usage: 25Mb 
Memory Usage: 21Mb 
Memory Usage: 25Mb 
Memory Usage: 22Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 30Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 23Mb 
Memory Usage: 34Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 40Mb 
Memory Usage: 36Mb 
Memory Usage: 33Mb 
Memory Usage: 30Mb 
Memory Usage: 41Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 30Mb 
Memory Usage: 27Mb 
Memory Usage: 23Mb 
Memory Usage: 34Mb 
Memory Usage: 31Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 38Mb 
Memory Usage: 36Mb 
Memory Usage: 33Mb 
Memory Usage: 30Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 23Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 27Mb 
Memory Usage: 38Mb 
Memory Usage: 35Mb 
Memory Usage: 33Mb 
Memory Usage: 30Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 23Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 30Mb 
Memory Usage: 27Mb 
Memory Usage: 38Mb 
Memory Usage: 35Mb 
Memory Usage: 33Mb 
Memory Usage: 30Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 23Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 38Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 24Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 30Mb 
Memory Usage: 27Mb 
Memory Usage: 38Mb 
Memory Usage: 35Mb 
Memory Usage: 20Mb 
Memory Usage: 32Mb 
Memory Usage: 28Mb 
Memory Usage: 26Mb 
Memory Usage: 23Mb 
Memory Usage: 34Mb 
Memory Usage: 31Mb 
Memory Usage: 29Mb 
Memory Usage: 26Mb 
Memory Usage: 38Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 20Mb 
Memory Usage: 31Mb 
Memory Usage: 28Mb 
Memory Usage: 26Mb 
Memory Usage: 23Mb 
Memory Usage: 34Mb 
Memory Usage: 31Mb 
Memory Usage: 28Mb 
Memory Usage: 40Mb 
Memory Usage: 37Mb 
Memory Usage: 34Mb 
Memory Usage: 22Mb 
Memory Usage: 33Mb 
Memory Usage: 29Mb 
Memory Usage: 27Mb 
Memory Usage: 38Mb 
Memory Usage: 35Mb 
Memory Usage: 32Mb 
Memory Usage: 31Mb 
Memory Usage: 42Mb 
Memory Usage: 38Mb 
Memory Usage: 38Mb 
Memory Usage: 36Mb 
Memory Usage: 21Mb 
Memory Usage: 32Mb 
Memory Usage: 28Mb 
Memory Usage: 25Mb 
Memory Usage: 36Mb 
Memory Usage: 34Mb 
Memory Usage: 32Mb 
Memory Usage: 29Mb 
Memory Usage: 40Mb 
Memory Usage: 38Mb 

script.js

'use strict'

const arrify = require('arrify')
const log = require('kittie')

const pubsub = require('./lib/pubsub')({
  keyFilename: './keyfile.json'
})

let count = 0;

;(async function() {
  const topic = await pubsub.getTopic('mem-test')
  const subscription = await topic.getSubscription('gce')

  listen(subscription)
}())

async function listen(subscription) {
  const stream = await subscription.streamingPull()

  stream
    .on('error', error => log.error(error))
    .on('data', data => {
      // log.info(`${data.receivedMessages.length} messages received.`)

      const ackIds = arrify(data.receivedMessages)
        .reduce((ids, message) => ids.concat(message.ackId), [])

      count += ackIds.length
      stream.ack(ackIds)

      if (count > 1000) {
        stream.pause()
        count -= 1000
        reportMemoryUsage(stream);
      }
    })
    .on('status', status => {
      log.info('Closing stream.');

      stream.destroy()

      if (isRetryable(status)) {
        return setImmediate(() => listen(subscription))
      }

      log.error('Unrecoverable error occured')
    })

  stream.write({
    subscription: subscription.name,
    streamAckDeadlineSeconds: 10
  })
}

function isRetryable(status) {
  return [0, 1, 4, 8, 13, 14].indexOf(status.code) > -1
}

function reportMemoryUsage(stream) {
  const mem = process.memoryUsage();
  console.log(`Memory Usage: ${Math.ceil(mem.heapUsed / 1000 / 1000, 2)}Mb`);
  setTimeout(function () {
    stream.resume()
  }, 2000)
}