lib/Store/Redis.php
public function set($type, $key, $value, $expire = null)
    {
        $redisKey = "{$this->prefix}.$type.$key";
        $this->redis->set($redisKey, serialize($value));

        if (is_null($expire)) {
            $expire = time() + $this->lifeTime;
        }
        $this->redis->expireat($redisKey, $expire);
    }
public function set($type, $key, $value, $expire = null)
    {
        $redisKey = "{$this->prefix}.$type.$key";
        $this->redis->set($redisKey, serialize($value));

        if (is_null($expire)) {
            $expire = time() + $this->lifeTime;
        }
        $this->redis->expireat($redisKey, $expire);
    }
Save a value to Redis

If no expiration time is given, then the expiration time is set to the
session duration.

@param string $type     The datatype
@param string $key      The key
@param mixed $value     The value
@param int|NULL $expire The expiration time (unix timestamp), or NULL if it never expires