javascript - 将同步 Map 方法转换为异步特征

Question

我有大量数据要转换成新格式。

实际上我正在使用 map 方法，但因为它是同步的并且会影响性​​能。

dataFormatted = cmtAllRawdataDB[0].rows.map(elm => new Message(elm, configResult));

有关Message 类的信息，全局格式如下:

export class Data {
  public value: string;
  public date: Date;
  constructor(dbData) {
    this.value = '123';
  }
}

export class Measure {
  public name: string;
  public unit: string;
  public data: Data[];
  constructor(config, dbData) {
    this.name = config.name;
    this.unit = config.value;
    ...
    this.data = [new Data(dbData)];
  }
}

export class Sensor {
  public id: string;
  public label: string;
  public measures: Measure[] = [];
  constructor(dbData, config) {
    this.id = '123';
    this.label = 'SensorType';
    config.unitConfig.map(elm => this.measures.push(new Measure(elm, dbData)));
  }
}

export class Message {
  public id: string;
  ...
  public sensors: Sensor[];
  constructor(dbData: any, config: any) {
    this.id = dbData.value._id;
    ....
    this.sensors = [new Sensor(dbData, config)];
    console.log(this.id, this.arrivalTimestamp);
  }
}

有没有办法异步运行这段代码？

Answer 1

把这个操作放在函数里面，放在settimeout方法里面，只需要10毫秒

var example = () => {
  setTimeout(() => {
    return (dataFormatted = cmtAllRawdataDB[0].rows.map(
      elm => new Message(elm, configResult)
    ));
  }, 10);
};