If it'll save others some head-scratching, the PECL Memcached extension only supports initializing increment (or decrement) values from 2.0.0b2 onwards - i.e. not the version (1.0.2) that comes out of the box with Ubuntu 12.04.
(PECL memcached >= 0.1.0)
Memcached::increment — 增加数值元素的值
$key
, int $offset = 1
) : int
Memcached::increment()
将一个数值元素增加参数 offset 指定的大小。如果元素的值不是数值类型，将返回错误。如果元素不存在，
Memcached::increment() 会将元素设置成
initial_value 指定的值。
key要增加值的元素的 key。
offset要将元素的值增加的大小。
initial_value如果元素不存在，要设置的默认值。
expiry设置元素值的过期时间。
成功时返回元素的新值 或者在失败时返回 false。
Example #1 Memcached::increment() 示例
<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
$m->set('counter', 0);
$m->increment('counter');
$n = $m->increment('counter', 10);
var_dump($n);
$m->set('counter', 'abc');
$n = $m->increment('counter');
// ^ will fail due to item value not being numeric
var_dump($n);
?>
以上例程会输出：
int(11) bool(false)
If it'll save others some head-scratching, the PECL Memcached extension only supports initializing increment (or decrement) values from 2.0.0b2 onwards - i.e. not the version (1.0.2) that comes out of the box with Ubuntu 12.04.
Spent a long time frustrated with this. If you read the patch notes carefully:
- Make increment/decrement initialize value when it is not available (when using binary protocol).
If you dont have the opt binary protocol set the arguments for initial value just return an error 38 - INVALID ARGUMENTS. This is not documented.
PECL memcached < 0.2.0
public int Memcached::increment ( string $key [, int $offset = 1 ] )
increment does not alter the time to live of the object.