如果超时则取消正则表达式匹配

Question

regex.match如果要花费10秒钟以上的时间才能取消操作？

我正在使用巨大的正则表达式来匹配特定的文本，有时可能有用，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..如果要花费10秒以上，我想取消操作。可能吗？我找不到与沙发有关的任何东西

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，但它应该可以工作。

如果你走这条路，叉子可能是你应该使用的。

如果您能原谅我的非纯函数，这段代码将演示如何在分叉子进程和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。您可能需要考虑像其他海报建议的那样重新编写正则表达式。