apcu_add

(PECL apcu >= 4.0.0)

apcu_add — Cache a new variable in the data store

说明

apcu_add ( string $key , mixed $var , int $ttl = 0 ) : bool

apcu_add ( array $values , mixed $unused = NULL , int $ttl = 0 ) : array

Caches a variable in the data store, only if it's not already stored.

Note: Unlike many other mechanisms in PHP, variables stored using apcu_add() will persist between requests (until the value is removed from the cache).

参数

key: Store the variable using this name. keys are cache-unique, so attempting to use apcu_add() to store data with a key that already exists will not overwrite the existing data, and will instead return false. (This is the only difference between apcu_add() and apcu_store().)
var: The variable to store
ttl: Time To Live; store var in the cache for ttl seconds. After the ttl has passed, the stored variable will be expunged from the cache (on the next request). If no ttl is supplied (or if the ttl is 0), the value will persist until it is removed from the cache manually, or otherwise fails to exist in the cache (clear, restart, etc.).
values: Names in key, variables in value.

返回值

Returns TRUE if something has effectively been added into the cache, FALSE otherwise. Second syntax returns array with error keys.

范例

Example #1 A apcu_add() example


<?php
$bar = 'BAR';
apcu_add('foo', $bar);
var_dump(apcu_fetch('foo'));
echo "\n";
$bar = 'NEVER GETS SET';
apcu_add('foo', $bar);
var_dump(apcu_fetch('foo'));
echo "\n";
?>

以上例程会输出：

string(3) "BAR"
string(3) "BAR"

参见

apcu_store() - Cache a variable in the data store
apcu_fetch() - Fetch a stored variable from the cache
apcu_delete() - Removes a stored variable from the cache

User Contributed Notes

sritter at satoya dot cz 27-Mar-2021 03:19


This is usable for locking/unlocking



<?php

do {} while (!apcu_add('lock_name', 'foo', 10));

// this part is protected against multiple/multithread run

apcu_delete('lock_name');