memdiff.php

<?php

function memdiff($id = null) {
    static $int = null;

    $current = memory_get_usage();

    if ($int === null) {
        $int = $current;
    } else {
        printf("MEM (%s) %d (%+d)\n", $id, $current, $current - $int);
        $int = $current;
    }
}