server/helpers/utils.js

   1 'use strict'
   2
   3 const crypto = require('crypto')
   4 const retry = require('async/retry')
   5
   6 const logger = require('./logger')
   7
   8 const utils = {
   9   badRequest,
  10   cleanForExit,
  11   generateRandomString,
  12   isTestInstance,
  13   getFormatedObjects,
  14   retryWrapper,
  15   transactionRetryer
  16 }
  17
  18 function badRequest (req, res, next) {
  19   res.type('json').status(400).end()
  20 }
  21
  22 function generateRandomString (size, callback) {
  23   crypto.pseudoRandomBytes(size, function (err, raw) {
  24     if (err) return callback(err)
  25
  26     callback(null, raw.toString('hex'))
  27   })
  28 }
  29
  30 function cleanForExit (webtorrentProcess) {
  31   logger.info('Gracefully exiting.')
  32   process.kill(-webtorrentProcess.pid)
  33 }
  34
  35 function isTestInstance () {
  36   return (process.env.NODE_ENV === 'test')
  37 }
  38
  39 function getFormatedObjects (objects, objectsTotal) {
  40   const formatedObjects = []
  41
  42   objects.forEach(function (object) {
  43     formatedObjects.push(object.toFormatedJSON())
  44   })
  45
  46   return {
  47     total: objectsTotal,
  48     data: formatedObjects
  49   }
  50 }
  51
  52 // { arguments, errorMessage }
  53 function retryWrapper (functionToRetry, options, finalCallback) {
  54   const args = options.arguments ? options.arguments : []
  55
  56   utils.transactionRetryer(
  57     function (callback) {
  58       return functionToRetry.apply(this, args.concat([ callback ]))
  59     },
  60     function (err) {
  61       if (err) {
  62         logger.error(options.errorMessage, { error: err })
  63       }
  64
  65       // Do not return the error, continue the process
  66       return finalCallback(null)
  67     }
  68   )
  69 }
  70
  71 function transactionRetryer (func, callback) {
  72   retry({
  73     times: 5,
  74
  75     errorFilter: function (err) {
  76       const willRetry = (err.name === 'SequelizeDatabaseError')
  77       logger.debug('Maybe retrying the transaction function.', { willRetry })
  78       return willRetry
  79     }
  80   }, func, callback)
  81 }
  82
  83 // ---------------------------------------------------------------------------
  84
  85 module.exports = utils