如果超时则取消正则表达式匹配 [英] Cancel Regex match if timeout

问题描述

如果要花费10秒钟以上的时间，是否可以取消regex.match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秒钟以上，我想取消操作.是否有可能?我没有找到与沙发有关的任何东西

谢谢.

解决方案

您可以生成一个进行正则表达式匹配的子进程，并在10秒钟内未完成将其终止.可能有点矫kill过正，但应该可以.

如果沿着这条路走，

叉应该是您应该使用的. /p>

如果您可以原谅我的非纯函数，那么这段代码将演示如何在派生的子进程与主进程之间来回通信的要旨:

index.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);

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所建议的那样对正则表达式进行返工.

Is it possible to cancel a regex.match operation if takes more than 10 seconds to complete?

I'm using an huge regex to match a specific text, and sometimes may work, and sometimes can fail...

regex: 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+

Working example: https://regex101.com/r/kU6rS5/1

So.. i want cancel the operation if takes more than 10 seconds. Is it possible? I'm not finding anything related in sof

Thanks.

解决方案

You could spawn a child process that does the regex matching and kill it off if it hasn't completed in 10 seconds. Might be a bit overkill, but it should work.

fork is probably what you should use, if you go down this road.

If you'll forgive my non-pure functions, this code would demonstrate the gist of how you could communicate back and forth between the forked child process and your main process:

index.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);

This might just end up masking the real problem, though. You may want to consider reworking your regex like other posters have suggested.

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