public function update($key, $value, $expire = 0)
{
if ($this->type === 1) {
return $this->memcache->replace($key, $value, $expire);
} else {
return $this->memcache->replace($this->conf['prefix'] . $key, json_encode($value, PHP_VERSION >= '5.4.0' ? JSON_UNESCAPED_UNICODE : 0), false, $expire);
}
}