本文实例讲述了go语言实现的memcache协议服务的方法。分享给大家供大家参考。具体如下：
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1. Go语言代码如下：
复制代码 代码如下:
package memcachep
import (
"bufio"
"fmt"
"io"
"strconv"
"strings"
)
//mc请求产生一个request对象
type MCRequest struct {
//请求命令
Opcode CommandCode
//key
Key string
//请求内容
Value []byte
//请求标识
Flags int
//请求内容长度
Length int
//过期时间
Expires int64
}
//request to string
func (req *MCRequest) String() string {
return fmt.Sprintf("{MCRequest opcode=%s, bodylen=%d, key='%s'}",
req.Opcode, len(req.Value), req.Key)
}
//将socket请求内容 解析为一个MCRequest对象
func (req *MCRequest) Receive(r *bufio.Reader) error {
line, _, err := r.ReadLine()
if err != nil || len(line) == 0 {
return io.EOF
}
params := strings.Fields(string(line))
command := CommandCode(params[0])
switch command {
case SET, ADD, REPLACE:
req.Opcode = command
req.Key = params[1]
req.Length, _ = strconv.Atoi(params[4])
value := make([]byte, req.Length+2)
io.ReadFull(r, value)
req.Value = make([]byte, req.Length)
copy(req.Value, value)
case GET:
req.Opcode = command
req.Key = params[1]
RunStats["cmd_get"].(*CounterStat).Increment(1)
case STATS:
req.Opcode = command
req.Key = ""
case DELETE:
req.Opcode = command
req.Key = params[1]
}
return err
}
2. Go语言代码：
复制代码 代码如下:
package memcachep
import (
"fmt"
"io"
)
type MCResponse struct {
//命令
Opcoed CommandCode
//返回状态
Status Status
//key
Key string
//返回内容
Value []byte
//返回标识
Flags int
//错误
Fatal bool
}
//解析response 并把返回结果写入socket链接
func (res *MCResponse) Transmit(w io.Writer) (err error) {
switch res.Opcoed {
case STATS:
_, err = w.Write(res.Value)
case GET:
if res.Status == SUCCESS {
rs := fmt.Sprintf("VALUE %s %d %d\r\n%s\r\nEND\r\n", res.Key, res.Flags, len(res.Value), res.Value)
_, err = w.Write([]byte(rs))
} else {
_, err = w.Write([]byte(res.Status.ToString()))
}
case SET, REPLACE:
_, err = w.Write([]byte(res.Status.ToString()))
case DELETE:
_, err = w.Write([]byte("DELETED\r\n"))
}
return
}
3. Go语言代码如下：
复制代码 代码如下:
package memcachep
import (
"fmt"
)
type action func(req *MCRequest, res *MCResponse)
var actions = map[CommandCode]action{
STATS: StatsAction,
}
//等待分发处理
func waitDispatch(rc chan chanReq) {
for {
input := <-rc
input.response <- dispatch(input.request)
}
}
//分发请求到响应的action操作函数上去
func dispatch(req *MCRequest) (res *MCResponse) {
if h, ok := actions[req.Opcode]; ok {
res = &MCResponse{}
h(req, res)
} else {
return notFound(req)
}
return
}
//未支持命令
func notFound(req *MCRequest) *MCResponse {
var response MCResponse
response.Status = UNKNOWN_COMMAND
return &response
}
//给request绑定上处理程序
func BindAction(opcode CommandCode, h action) {
actions[opcode] = h
}
//stats
func StatsAction(req *MCRequest, res *MCResponse) {
res.Fatal = false
stats := ""
for key, value := range RunStats {
stats += fmt.Sprintf("STAT %s %s\r\n", key, value)
}
stats += "END\r\n"
res.Value = []byte(stats)
}
希望本文所述对大家的Go语言程序设计有所帮助。
js
