go語言七——串連redis

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

使用Redigo這個庫

package mainimport ("fmt""redis""time""strconv")var (server string = "192.168.1.105:6379"password string = "passwd")var pool *redis.Poolfunc test(i int) {c := pool.Get()defer c.Close()t:=strconv.Itoa(i)c.Do("SETEX","foo"+t,20,i)reply, err := redis.Int(c.Do("GET","foo"+t))if err == nil {fmt.Print(reply)} else {fmt.Print(err)}time.Sleep(1*time.Second)}func poolInit() (*redis.Pool) {//redis poolreturn &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}if _, err := c.Do("AUTH", password); err != nil {c.Close()return nil, err}//if _, err := c.Do("SELECT",1); err != nil {// c.Close()// return nil, err//}return c, err},TestOnBorrow: func(c redis.Conn, t time.Time) error {_, err := c.Do("PING")return err},}}func main() {pool = poolInit()for i:=0;i<1000000;i++ {test(i)}}

 如果伺服器連接埠不可用或者服務i不可用，則c.Do會返回錯誤，連接埠不可用立即返回Connection Refused，而伺服器不可達會等待一段時間逾時再返回。下面這段代碼實現先尋找緩衝，查詢失敗時查詢mysql

type Record struct {    Key string    Val string}func fetch_key(key string) string {        var val string        out := make(chan string)        timeout := make(chan string, 1)        //逾時兩秒        go func() {                time.Sleep(2 * time.Second)                timeout <- ""        }()        //查詢快取(Redis)        c := G_pool.Get()        defer c.Close()        if reply, err := redis.String(c.Do("GET", key)); err == nil {                go func(string) {                        out <- reply                }(reply)        } else {                go func() {                        //查詢資料庫(Mysql)                        db, e := sql.Open("mysql", "username:password@tcp(mysqlip:mysqlport)/dbname?charset=utf8")                        if e != nil {                                out <- ""                        }                        defer db.Close()                        rows, e := db.Query("select key,val from dbname.tablename where key=" + key)                        if e != nil {                                out <- ""                        }                        if rows == nil {                                out <- ""                        }                        for rows.Next() {                                rec := new(Record)                                row_err := rows.Scan(&rec.Key,&rec.Val)                                if row_err != nil {                                        out <- ""                                }                                //將結果存入緩衝(Redis),逾時1天                                c.Do("SETEX",key,86400,rec.Val)                                out <- rec.Size                        }                        out <- ""                }()        }        //等待結果或者逾時        select {                case val = <-timeout:                case val = <-out:        }        return val}