Is there a way I get the size of a PHP variable in bytes?

Question

I currently have a PHP CLI script using Zend Framework extensively which seems to be using a ever larger amount of memory as it runs. It loops through a large set of models

Answer 1

No. You are likely looking for memory that is not freed, e.g. you unlinked a variable or deleted a reference and the garbage collector did not yet release the associated block in memory.

You could try Zend Server 5 (you need the commercial version though) to mem-profile your application. It has code tracing. I dont know if this would allow you to spot memory leaks though.

Also see:

• What's new in PHP V5.2, Part 1: Using the new memory manager
• Memtrack (PECL)

Answer 2

Here is a code snippet I found at weberdev

<?php
function array_size($a){
    $size = 0;
    while(list($k, $v) = each($a)){
        $size += is_array($v) ? array_size($v) : strlen($v);
    }
    return $size;
}
?>

It gets the size of the given array in bytes. Is this what you meant?

Answer 3

i don't have a solution to check the size of every variable, but if you use doctrine its probably the reason

you need to use

   $Elem->free(true);

another thing is to upgrade to 5.3 (if you dont do it yet), the garbage collector of 5.3 is better

Answer 4

I don't know how accurate it is, but I got a number by using apc_add('variable_name', $var);. I then go to my apc.php under user cache entries and look at the size column.

Of course for this to work you need to have APC installed and running. :-)