php教程

apcu_cas

(PECL apcu >= 4.0.0)

apcu_casUpdates an old value with a new value

说明

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

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

参数

key

The key of the value being updated.

old

The old value (the value currently stored).

new

The new value to update to.

返回值

成功时返回 TRUE, 或者在失败时返回 FALSE

范例

Example #1 apcu_cas() example

<?php
apcu_store
('foobar'2);
echo 
'$foobar = 2'PHP_EOL;
echo 
'$foobar == 1 ? 2 : 1 = ', (apcu_cas('foobar'12) ? 'ok' 'fail'), PHP_EOL;
echo 
'$foobar == 2 ? 1 : 2 = ', (apcu_cas('foobar'21) ? 'ok' 'fail'), PHP_EOL;

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

echo 
'$f__bar == 1 ? 2 : 1 = ', (apcu_cas('f__bar'12) ? 'ok' 'fail'), PHP_EOL;

apcu_store('perfection''xyz');
echo 
'$perfection == 2 ? 1 : 2 = ', (apcu_cas('perfection'21) ? 'ok' 'epic fail'), PHP_EOL;

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

以上例程的输出类似于:

$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

参见

User Contributed Notes

Anonymous 03-Feb-2018 12:49
The output in the example says:

$f__bar == 1 ? 2 : 1 = fail

but in reality it should be:

$f__bar == 1 ? 2 : 1 =  ok

the first time the code is ran as the cache is empty and apcu_cas allows the key to be inserted.

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