Storing 4000 image files per directory - php

Question

So I want to store about 4k images in one directory, like this: uploads/uniqid()./file.jpg and uploads/uniqid()./thumb/file.jpg
Now, the problem is the way I want to do it, I don't thinks is the best way.
I want to have a table, where I store the active directory name that has less then 4k images in it.
So when a user uploads an image, I will go in that directory count the files, and if it'S less the 4k I will upload the image there, if the are 4000 images in the directory I will create a new directory name using uniqid() and put the file in the new directory, I will also update the table with the new active directory name.
I think this solution is ok, except that I will have to count the files each time a user uploads an image, what do you think guys?

Answer 1

An alternative to counting the files would be to add a counter (ie: autoincrement) field to a table, and insert a row in the table when a user uploads a file. You could then use mysql_insert_id() to get the id for the row you just inserted.
Then simply add the following to see if you need to create a new directory:
if((mysql_insert_id() % 4000) === 0) {
//create new dir name
//insert new dir name into table as active dirname
//add image to new folder
}
else {
//add image to active directory
}