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 }

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 }

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) }