Question

我现在有点陷入竞争状态，我把头发拉了出来。基本上，我查询API，将结果添加到数据库，然后使用返回/保存的数据执行操作。

我对这个具体问题的了解较少，更多的是如何解决这类问题的设计模式。第p.push(formatter.createAccounts(account, id));行可能会运行1000次，可能需要20秒左右。

关于我做错的任何想法都会非常有帮助

谢谢，奥利

// get all users
Promise.all(updatedUsers)
.then(() => {
  // create an array of promises
  const p = [];

  users.then((user) => {
    ...
    ids.forEach((id) => {
      const accounts = foo.getAccounts(id, true); // returns a promise
      accounts.then((account) => {
        // add the return data from here to the promise array at the bottom
        p.push(formatter.createAccounts(account, id));
      });
    });
  });

  // this would ideally be a promise array of the data from above - but instead it just evaluates to [] (what it was set to).
  Promise.all(p).then(() => {
    // do my stuff that relies on the data here
  })
});

Answer 1

问题是您没有将foo.getAccounts承诺包含在promises数组中。修改版：

Promise.all(updatedUsers)
.then(() => {

  users.then((user) => {
    return Promise.all(ids.map(id => {
      //for each ID we return a promise
      return foo.getAccounts(id, true).then(account => {
        //keep returning a promise
        return formatter.createAccounts(account, id)
      })

    }).then((results) => {
      //results is an array of the resolved values from formatter.createAccounts
      // do my stuff that relies on the data here
    })
  })

 //rest of closing brackets

承诺和竞争条件

1 个答案: