Php/docs/function.apcu-add
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 $ttl
= 0
]] ) : array
Caches a variable in the data store, only if it's not already stored.
Note:
Unlike many other mechanisms in PHP, variables stored using apcu_add() will persist between requests (until the value is removed from the cache).
参数
key
- Store the variable using this name.
key
s are cache-unique, so attempting to use apcu_add() to store data with a key that already exists will not overwrite the existing data, and will instead returnfalse
. (This is the only difference between apcu_add() and apcu_store().) var
- The variable to store
ttl
- Time To Live; store
var
in the cache forttl
seconds. After thettl
has passed, the stored variable will be expunged from the cache (on the next request). If nottl
is supplied (or if thettl
is0
), the value will persist until it is removed from the cache manually, or otherwise fails to exist in the cache (clear, restart, etc.). values
- Names in key, variables in value.
返回值
Returns TRUE if something has effectively been added into the cache, FALSE otherwise. Second syntax returns array with error keys.
范例
Example #1 A apcu_add() example
<?php$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