281622 - Opening a directory with many sub directories is slow (3 times slower than with 10.000 files)

Status: RESOLVED INVALID

(Core :: Networking: File, defect)

Description

[Henrik Gemal]

My extension needs to read the current temp directory.

I've experienced this:
When reading a directory with 10.000 files it takes around 1200 ms to complete

BUT
When reading a directory with 10.000 subdirectories it takes around 3500 ms to
complete. almost 3 times as long

my code is something like this:
-----------------
var tmpdir = Launchy_DirIO.get("TmpD");
var dir = Launchy_DirIO.open(tmpdir.path);
var contents = Launchy_DirIO.read(dir, true);
-----------------

it's the call to .read that takes a long time.

User Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b)
Gecko/20050208 Firefox/1.0+

I'd be happy to provide more info

Comment 1

[Christian :Biesinger (don't email me, ping me on IRC)]

what do these Launchy_IO methods actually do?

Comment 2

[Henrik Gemal]

I use the http://gratisdei.com/io.js
and it seems that the dir.isDirectory() call on every file in the directory is
to blame.

closing since this turns out to be an issue of an external io module

Comment 3

[Darin Fisher]

Henrik: this is a classic problem with visual file explorers.  unfortunately, it
is costly to "stat" files to determine their type.  try opening both directories
in the file explorer on your operating system.  you may notice that nautilus for
one appears to update the type of the file lazily.  accessing file system meta
data is a bottleneck in most file systems.  it would seem that they were not
designed with the demands of user interfaces in mind ;-)