redigo snippet for ISUCON

redigo.go

// global variable for redis connection pool
        var server = "localhost:6379"
        var Pool = redis.Pool{
        MaxIdle:     3,
        IdleTimeout: 240 * time.Second,

        Dial: func() (redis.Conn, error) {
                c, err := redis.Dial("tcp", server)

                if err != nil {
                        return nil, err
                }
                return c, err
        },

        TestOnBorrow: func(c redis.Conn, t time.Time) error {
                _, err := c.Do("PING")
                return err
        },
}


// cache to redis alternative to haveread table
        rconn := Pool.Get()
        defer rconn.Close()
        latestID := messages[0].ID
        rconn.Do("SET", fmt.Sprintf("u%dc%d", userID, chanID), fmt.Sprintf("%d", latestID))

        rconn := Pool.Get()
        defer rconn.Close()
        id, _ := redis.Int64(rconn.Do("GET", fmt.Sprintf("u%dc%d", userID, chID)))
        if id != 0 {
           return id, nil
        } else {
          return 0, nil
        }
// redis init
        rconn := Pool.Get()
        defer rconn.Close()
        rconn.Do("flushdb")
        rconn.Do("SET", "flushed", "yeah")