class WeixinAuthorize::Token::RedisStore

def access_token
  super
  client.access_token = weixin_redis.hget(client.redis_key, "access_token")
  client.expired_at   = weixin_redis.hget(client.redis_key, "expired_at")
  client.access_token
end

def refresh_token
  super
  weixin_redis.hmset(client.redis_key, "access_token", client.access_token,
                                       "expired_at",   client.expired_at)
  weixin_redis.expireat(client.redis_key, client.expired_at.to_i-10) # 提前10秒超时
end

def token_expired?
  weixin_redis.hvals(client.redis_key).empty?
end

def valid?
 weixin_redis.del(client.redis_key)
 super
end

def weixin_redis
  WeixinAuthorize.weixin_redis
end