worker-item.js

const { parentPort } = require('worker_threads')
const sql = require('msnodesqlv8')
const { TestEnv } = require('../../test/env/test-env')
const env = new TestEnv()
const connectionString = env.connectionString

async function compute (msg) {
  try {
    console.log(`worker receive task ${msg.num}`)
    const conn = await sql.promises.open(connectionString)
    const query = `select ${msg.num} as i, @@SPID as spid`
    const res = await conn.promises.query(query)
    await conn.promises.close()
    parentPort.postMessage(
      {
        command: 'task_result',
        data: `spid ${res.first[0].spid}`,
        num: msg.num,
        fib: getFib(msg.num)
      })
  } catch (e) {
    parentPort.emit('error', e)
  }
}

parentPort.on('message', async msg => {
  switch (msg.command) {
    case 'task': {
      await compute(msg)
      break
    }
    default: {
      console.log(`unknown command ${msg.command}`)
      break
    }
  }
})

function getFib (num) {
  if (num === 0) {
    return 0
  } else if (num === 1) {
    return 1
  } else {
    return getFib(num - 1) + getFib(num - 2)
  }
}