All dirs in the watch dir are opened, easily causing too many open files

[nicolasartman]

I noticed from #3 that there's a deliberate design decision to watch all dirs in case any new files appear that might match the glob. I can see why this would be helpful in some cases, but it breaks things in others, so a choice would be excellent.

var sane = require('sane');
// Wouldn't actually watch anything, but will crash immediately
sane('/Users/nick/', ['**/fdjsaiofjidosafjioadsfjidosa*']);

As far as I can tell, there's no reasonable way to prevent that from crashing, because there are simply too many dirs opened for watching at once (even with a massive ulimit increase).

My request is that a flag be added to make only files matching the glob on startup get watched. My core use case is for fb-flo, where I want to watch projectdir/static/minified/js/**/*.js and projectdir/static/templates/**/*.html, but there are simply too many dirs under projectdir/static to open them all at once.

Thanks!

[matthewmueller]

+1

[DavidSouther]

@nicolasartman I understand where you're going and agree that it's a useful feature, though why don't you have two watches, one for each glob?

[amasad]

I thought I'd replied here, must've been another thread. If sane where to predict what could be watched or not, it needs a much deeper understanding of globs, which is probably doable.

Are you actively hitting this problem?
I personally haven't seen a problem with this on OSX and linux with a lot of watched dirs.

Also have you looked into the WatchmanWatcher, I recommend it for larger projects because there is no way to prevent #25

[stefanpenner]

@amasad if Im understanding this correctly, basically if we made watch(dir) aware of globing, specifically partial globs, we could avoid watching directories who's containing files/directories couldn't possible match. Correct?

I did something I believe is the same with minimatch to ensure node-walk-sync wouldn't traverse directories it should not traverse.

I'll try and poke around sometime, and see if micromatch exposes similar capability.