server/helpers/database-utils.js

   1 'use strict'
   2
   3 const retry = require('async/retry')
   4
   5 const db = require('../initializers/database')
   6 const logger = require('./logger')
   7
   8 const utils = {
   9   retryTransactionWrapper,
  10   transactionRetryer,
  11   startSerializableTransaction
  12 }
  13
  14 // { arguments, errorMessage }
  15 function retryTransactionWrapper (functionToRetry, options, finalCallback) {
  16   const args = options.arguments ? options.arguments : []
  17
  18   utils.transactionRetryer(
  19     function (callback) {
  20       return functionToRetry.apply(this, args.concat([ callback ]))
  21     },
  22     function (err) {
  23       if (err) {
  24         logger.error(options.errorMessage, { error: err })
  25       }
  26
  27       // Do not return the error, continue the process
  28       return finalCallback(null)
  29     }
  30   )
  31 }
  32
  33 function transactionRetryer (func, callback) {
  34   retry({
  35     times: 5,
  36
  37     errorFilter: function (err) {
  38       const willRetry = (err.name === 'SequelizeDatabaseError')
  39       logger.debug('Maybe retrying the transaction function.', { willRetry })
  40       return willRetry
  41     }
  42   }, func, callback)
  43 }
  44
  45 function startSerializableTransaction (callback) {
  46   console.log(db)
  47   db.sequelize.transaction({ isolationLevel: 'SERIALIZABLE' }).asCallback(function (err, t) {
  48     // We force to return only two parameters
  49     return callback(err, t)
  50   })
  51 }
  52
  53 // ---------------------------------------------------------------------------
  54
  55 module.exports = utils