Optimization of algorithms for complex patterns

Environment

• OS Version: Manjaro Linux x86_64
• Node.js Version: v11.8.0

Actual behavior

(node:22393) UnhandledPromiseRejectionWarning: Error: EACCES: permission denied

Steps to reproduce and Code sample

.
├── dir
│   ├── one
│   │   ├── a
│   │   │   └── 1.js
│   │   └── b
│   │       └── 2.js
│   └── two [error opening dir]
├── dir2
│   └── one
│       ├── a
│       │   └── 1.js
│       └── b
│           └── 2.js
├── fast-glob.js
├── package.json
└── package-lock.json

// fast-glob.js
const fg = require('fast-glob');
fg(['+(dir|dir2)/one/**/*']).then((entries) => console.log(entries));

$ node fast-glob.js
(node:22859) UnhandledPromiseRejectionWarning: Error: EACCES: permission denied, scandir '/home/keenwon/Test/fast-glob-test/dir/two'
(node:22859) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:22859) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

current user doesn’t have permission to access dir/two:

total 8.0K
drwxr-xr-x 4 keenwon keenwon 4.0K 2月  13 17:37 one
dr-x------ 2 root    root    4.0K 2月  13 17:54 two

[mrmlnc]

Will be available with fast-glob@3.2.0 (#251).

[mrmlnc]

Just another try to split pattern into segments. This works for most of the patterns from the micromatch tests (random selection).

'use strict';

const mm = require('../micromatch');
const { Minimatch } = require('minimatch');
const utils = require('../fast-glob/out/utils');

const PATTERN = 'root/+(dir1|dir2)/one/**/*';

const mn = new Minimatch(PATTERN);

console.dir(mn, { colors: true });

const buildSegments = (tokens) => {
  const segments = [];
  let segment = '';

  const state = {
    parens: 0
  };

  let index = 0;

  while (index < tokens.length) {
    const token = tokens[index];

    if (token.type === 'paren') {
      if (token.value === '(') {
        state.parens++;
      }
      if (token.value === ')') {
        state.parens--;
      }
    }

    if ((token.type === 'slash' && state.parens === 0)) {
      segments.push(segment);
      segment = '';
    } else {
      segment += token.value;
    }

    index++;
  }

  segments.push(segment);

  return segments;
};

const makeSegments = (pattern) => {
  const [result] = mm.parse(pattern);

  if (pattern === '') {
    return [];
  }

  // mm.parse returns [bos] for aa*.txt
  if (result.tokens.length === 1 && result.tokens[0].type === 'bos') {
    return [pattern];
  }

  return buildSegments(result.tokens);
};

const convertPatternsToSegments = (patterns) => patterns.map(makeSegments);

const prepare = (pattern) => {
  return mm.braceExpand(PATTERN);
};

const makeRe = (segments) => {
  return segments.map(segment => {
    return segment.map(part => utils.pattern.isDynamicPattern(part) ? mm.makeRe(part) : part);
  });
};

const patterns = prepare(PATTERN);
const segments = convertPatternsToSegments(patterns);
const final = makeRe(segments);

console.dir(final, { colors: true });

const parts = [
  [
    'root',
    /^(?:(?=.)(?:dir1|dir2)+)$/,
    'one',
    /^(?:(?!\.)(?:(?:(?!(?:^|[\\/])\.).)*?)[\\/]?)$/,
    /^(?:(?!\.)(?=.)[^\\/]*?[\\/]?)$/
  ]
];

const files = [
  'root/dir1/a/1.js', // +, +, -
  'root/dir1/b/2.js', // +, +, -
  'root/dir1/two', // +, +, -
  'root/dir2/one/a/1.js', // +, +, +, +, +
  'root/dir2/one/b/2.js',  // +, +, +, +, +
  'root/fast-glob.js', // +, -
  'root/package.json' // +, -
];