threads

rpc.js

/**
 * rpc mini impl
 * @author 神说要有光
 */
let id = 0
function getId() {
  return id++
}

const callMap = new Map()

function rpc(method, params) {
  const curId = getId()
  postMessage({
    messageId: curId,
    method,
    params
  })
  return new Promise((resolve, reject) => {
    callMap.set(curId, {
      resolve, 
      reject
    })
  })
}

addEventListener('message', (evt) => {
  const { messageId, res, method, params } = evt.data
  if (res) {
    const { resolve, reject } = callMap.get(messageId)
    if (res.error) {
      reject(res.error)
    } else {
      resolve(res.data)
    }
  } else {
    try {
      const res = this[method](...params)
      postMessage({
        messageId,
        data: res
      })
    } catch(e) {
      postMessage({
        messageId,
        error: e
      })
    }
  }
})