keeping an include file in memory

sfullman

This gets into how the pHP engine fucntions and if there's any way I can tweak it for performance.

Suppose Ihave a site with say hundreds of pages, but most all have

require('config.php');

at the head of them, which contains functions, connections to the db, etc.

Is there any way I can have that file near-permanently reside in memory so that that call can be that much faster? is this a PHP thing or a Linux thing?

In case you didn't already know, I thought of this idea because IE keeps .js and .css links in memory from page to page on a site (it just checks the file date hasn't changed since the last visit). Second visits to any page using the same .js script are faster. I'd like to implement the same concept on the server side.

Very gratefully,
Sam Fullman

leatherback

Hi,

What you seem to forget is that .js and .css files are keep -locally- on the HD of the user. This safes a lot of time, because all this info doesn't have to be transported over the internet.

On the server this would correspond to keeping the includes on the harddrive of the server -where they already are-

Before you spend a lot of time on this, I would have a look at things like acces times for files on the server, and compare them to download times through low/mediumhigh speed internet connections.
I do not think there is a lot of time to be won. Certainly not the sort of time a user would notice.
Unless you are doing it for a different reason, I would not worry about it.

My .02

mogster

You could use the prepend in php.ini.

auto_prepend_file = /path/to/config/config.php

As far as I can remember these data is kept in memory, but I'm not sure.
This will limit the server to only one db, though - so you probably should check out PEAR or some other lib that enables more db's through classes.

I used _phplib once (with a connect class), and as I remember, I had to restart apache when editing the prepended file to see the changes take effect.
Proof that the file isn't read from disk on each pageload?

knutm :-)

sfullman

your response was probably the best, so is there a specific way to test that a file is being read from memory and not the disk?

Sam

mogster

Yes, there is.
If you use the prepend:

Change the file, then reload the page. If it changes it's read from disk. If you have to restart the webserver, it's resides in memory.

When I used phplib I had to restart the webserver to get access to added db's.

knutm :-)