javascript - 如果超时则取消正则表达式匹配

Question

如果需要超过 10 秒才能完成，是否可以取消 regex.match 操作？

我正在使用一个巨大的正则表达式来匹配特定的文本，有时可能有效，有时可能会失败...

正则表达式:MINISTÉRIO(?:[^P]*(?:P(?!ÁG\s:\s\d+\/\d+)[^P]*)(?:[\s\S]*?))PÁG\s:\s+\d+\/(\d+)\b(?:\D*(?:(?!\1\/\1)\d\D*)*)\1\/\1(?:[^Z]*(?:Z(?!6:\s\d+)[^Z]*)(?:[\s\S]*?))Z6:\s+\d+

工作示例:https://regex101.com/r/kU6rS5/1

所以.. 如果超过 10 秒，我想取消操作。是否可以？我没有在 sof 中找到任何相关内容

谢谢。

Answer 1

您可以生成一个执行正则表达式匹配的子进程，如果它在 10 秒内未完成则将其终止。可能有点矫枉过正，但它应该有效。

fork如果您沿着这条路走下去，这可能是您应该使用的。

如果你能原谅我的非纯函数，这段代码将演示如何在 fork 的子进程和你的主进程之间来回通信的要点:

索引.js

const { fork } = require('child_process');
const processPath = __dirname + '/regex-process.js';
const regexProcess = fork(processPath);
let received = null;

regexProcess.on('message', function(data) {
  console.log('received message from child:', data);
  clearTimeout(timeout);
  received = data;
  regexProcess.kill(); // or however you want to end it. just as an example.
  // you have access to the regex data here.
  // send to a callback, or resolve a promise with the value,
  // so the original calling code can access it as well.
});

const timeoutInMs = 10000;
let timeout = setTimeout(() => {
  if (!received) {
    console.error('regexProcess is still running!');
    regexProcess.kill(); // or however you want to shut it down.
  }
}, timeoutInMs);

regexProcess.send('message to match against');

regex-process.js

function respond(data) {
  process.send(data);
}

function handleMessage(data) {
  console.log('handing message:', data);
  // run your regex calculations in here
  // then respond with the data when it's done.

  // the following is just to emulate
  // a synchronous computational delay
  for (let i = 0; i < 500000000; i++) {
    // spin!
  }
  respond('return regex process data in here');
}

process.on('message', handleMessage);

不过，这可能最终掩盖了真正的问题。您可能需要像其他发帖人建议的那样考虑修改您的正则表达式。