apcu_cas

(PECL apcu >= 4.0.0)

Updates an old value with a new value

bool apcu_cas ( string $key, int $old, int $new )

apcu_cas() updates an already existing integer value if the old parameter matches the currently stored value with the value of the new parameter.

Parameters:

key

The key of the value being updated.

old

The old value (the value currently stored).

new

The new value to update to.

Returns:

Returns TRUE on success or FALSE on failure.

Examples:

apcu_cas() example

<?php
apcu_store('foobar', 2);
echo '$foobar = 2', PHP_EOL;
echo '$foobar == 1 ? 2 : 1 = ', (apcu_cas('foobar', 1, 2) ? 'ok' : 'fail'), PHP_EOL;
echo '$foobar == 2 ? 1 : 2 = ', (apcu_cas('foobar', 2, 1) ? 'ok' : 'fail'), PHP_EOL;

echo '$foobar = ', apcu_fetch('foobar'), PHP_EOL;

echo '$f__bar == 1 ? 2 : 1 = ', (apcu_cas('f__bar', 1, 2) ? 'ok' : 'fail'), PHP_EOL;

apcu_store('perfection', 'xyz');
echo '$perfection == 2 ? 1 : 2 = ', (apcu_cas('perfection', 2, 1) ? 'ok' : 'epic fail'), PHP_EOL;

echo '$foobar = ', apcu_fetch('foobar'), PHP_EOL;
?>

The above example will output something similar to:

$foobar = 2
$foobar == 1 ? 2 : 1 = fail
$foobar == 2 ? 1 : 2 = ok
$foobar = 1
$f__bar == 1 ? 2 : 1 = fail
$perfection == 2 ? 1 : 2 = epic fail
$foobar = 1