Time to find a non glob path increase with number of files in the same directory

Environment

• OS Version: OSX 10.12.6
• Node.js Version: 9.50

Actual behavior

When searching for a single file (no glob parts in the path), the time increase with as the number of files in the same directory increase. With node-glob this time is constant.

Find 1 file in a directory with 1 file (ran 500 times):

• node-glob: 48.868ms
• fast-glob: 118.218ms

Find 1 file in a directory with 500 file (ran 500 times):

• node-glob: 45.647ms
• fast-glob: 1935.108ms

Find 1 file in a directory with 2000 file (ran 500 times):

• node-glob: 48.535ms
• fast-glob: 7538.522ms

Expected behavior

Globbing a static path (with no wildcards) is a something that can happen sometimes in modules that get the glob patterns from user input, as users can pass a list of file path (e.g, mymodule file1.js file2.js file3.js ).

It seems that node-glob has a way to detect those cases and optimize them. There is potential gain of perf in fast-glob by implementing the same type of optimization.

Steps to reproduce

Use the code below and change the TOTAL_FILES to measure the changes in the globbing time between fast-glob and node-glob.

Code sample

const fs = require('fs');
const path = require('path');
const glob = require('glob');
const fg = require('fast-glob');

const TOTAL_FILES = 2000;

fs.mkdirSync('test')
for (let i = 0; i < TOTAL_FILES; i++) {
  const filepath = path.join('test', `file-${i}`);
  fs.writeFileSync(filepath, '');
}

console.time('node-glob');
for (let i = 0; i < 500; i++) {
  glob.sync('test/file-1')
}
console.timeEnd('node-glob');

console.time('fast-glob');
for (let i = 0; i < 500; i++) {
  fg.sync('test/file-1')
}
console.timeEnd('fast-glob');

[mrmlnc]

I prefer solution with is-glob with strict mode. In this case we needs have a separated tasks for static and dynamic patterns (just like the dynamic property in the ITask interface). Then, when processing a task, simply pass them to the correct adapters (fs and readdir-enhanced).

I’ve already started working on this issue.

[mrmlnc]

Must be fixed by fast-glob@2.1.0. Please, read release notes for more details.

Thanks for reporting ❤️!