package memcachep

import (

    "bufio"

    "fmt"

    "io"

    "strconv"

    "strings"

)

//mc請(qǐng)求產(chǎn)生一個(gè)request對(duì)象

type MCRequest struct {

    //請(qǐng)求命令

    Opcode CommandCode

    //key

    Key string

    //請(qǐng)求內(nèi)容

    Value []byte

    //請(qǐng)求標(biāo)識(shí)

    Flags int

    //請(qǐng)求內(nèi)容長(zhǎng)度

    Length int

    //過(guò)期時(shí)間

    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)

}

//將socket請(qǐng)求內(nèi)容 解析為一個(gè)MCRequest對(duì)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語(yǔ)言代碼：

復(fù)制代碼代碼如下:

package memcachep

import (

    "fmt"

    "io"

)

type MCResponse struct {

    //命令

    Opcoed CommandCode

    //返回狀態(tài)

    Status Status

    //key

    Key string

    //返回內(nèi)容

    Value []byte

    //返回標(biāo)識(shí)

    Flags int

    //錯(cuò)誤

    Fatal bool

}

//解析response 并把返回結(jié)果寫(xiě)入socket鏈接

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語(yǔ)言代碼如下：

復(fù)制代碼代碼如下:

package memcachep

import (

    "fmt"

)

type action func(req *MCRequest, res *MCResponse)

var actions = map[CommandCode]action{

    STATS: StatsAction,

}

//等待分發(fā)處理

func waitDispatch(rc chan chanReq) {

    for {

        input := <-rc

        input.response <- dispatch(input.request)

    }

}

//分發(fā)請(qǐng)求到響應(yīng)的action操作函數(shù)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

}

//給request綁定上處理程序

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)

}