In case anyone is puzzled by the function name, "cas" refers to http://en.wikipedia.org/wiki/Compare-and-swap
apc_cas
(PECL apc >= 3.1.1)
apc_cas — Updates an old value with a new value
說明
bool apc_cas
( string
$key
, int $old
, int $new
)
apc_cas() updates an already existing integer value if the
old parameter matches the currently stored value
with the value of the new parameter.
參數
-
key -
The key of the value being updated.
-
old -
The old value (the value currently stored).
-
new -
The new value to update to.
回傳值
如果成功則回傳 TRUE，失敗則回傳 FALSE。
範例
Example #1 apc_cas() example
<?php
apc_store('foobar', 2);
echo '$foobar = 2', PHP_EOL;
echo '$foobar == 1 ? 2 : 1 = ', (apc_cas('foobar', 1, 2) ? 'ok' : 'fail'), PHP_EOL;
echo '$foobar == 2 ? 1 : 2 = ', (apc_cas('foobar', 2, 1) ? 'ok' : 'fail'), PHP_EOL;
echo '$foobar = ', apc_fetch('foobar'), PHP_EOL;
echo '$f__bar == 1 ? 2 : 1 = ', (apc_cas('f__bar', 1, 2) ? 'ok' : 'fail'), PHP_EOL;
apc_store('perfection', 'xyz');
echo '$perfection == 2 ? 1 : 2 = ', (apc_cas('perfection', 2, 1) ? 'ok' : 'epic fail'), PHP_EOL;
echo '$foobar = ', apc_fetch('foobar'), PHP_EOL;
?>
上例的輸出類似於：
$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
參見
- apc_dec() - Decrease a stored number
- apc_store() - Cache a variable in the data store
add a note
User Contributed Notes 1 note
Piet Delport ¶
13 years ago
