Go语言：带有缓冲区的字节流读写（bufio.Reader/bufio.Writer）的示例之redis读写

在上一篇《Go语言：字节流读写（io.Reader/io.Writer）的示例之redis读写》的基础上，本篇把缓冲区加上去。

bufio包有两个New函数，分别是在任意io.Reader和io.Writer的基础上再包装一层缓冲区得到bufio.Reader和bufio.Writer。
func NewReader(rd io.Reader) *Reader
func NewWriter(w io.Writer) *Writer

下面的代码利用bufio来执行两条redis客户端操作，需要注意的是bufio.Writer在调用完Write之后还需要调用Flush清空缓冲区。

127.0.0.1:6380> set key 75
OK
127.0.0.1:6380> get key
"75"

package main

import (
        "fmt"
        "io"
        "bufio"
        "net"
)

func exec(wr *bufio.Writer, rd *bufio.Reader, cmd string) (string, error) {
        var err error
        _, err = wr.Write([]byte(cmd))
        if err != nil {
                return "", err
        }
        wr.Flush()

        var p []byte = make([]byte, 1024, 1024)
        _, err = rd.Read(p)
        if err != nil && err != io.EOF {
                return "", err
        }
        return string(p), nil
}

func main() {
        var conn net.Conn
        var err error
        conn, err = net.Dial("tcp", "127.0.0.1:6380")
        if err != nil {
                fmt.Printf("err=%v\n", err)
                return
        }
        var reply string
        wr := bufio.NewWriter(conn)
        rd := bufio.NewReader(conn)
        //set key 75
        reply, err = exec(wr, rd, "*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$2\r\n75\r\n")
        fmt.Printf("set key 75's reply=%s err=%v\n", reply, err)
        //get key
        reply, err = exec(wr, rd, "*2\r\n$3\r\nGET\r\n$3\r\nkey\r\n")
        fmt.Printf("get key's reply=%s err=%v\n", reply, err)
}

输出：

set key 75's reply=+OK
 err=<nil>
get key's reply=$2
75
 err=<nil>