protocol.go

/**
 * Copyright (c) 2014-2015, GoBelieve     
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package main

import "io"
import "bytes"
import "encoding/binary"
import log "github.com/golang/glog"
import "fmt"
import "errors"

//deprecated
const MSG_HEARTBEAT = 1
const MSG_AUTH = 2

const MSG_AUTH_STATUS = 3
//persistent
const MSG_IM = 4

const MSG_ACK = 5
const MSG_RST = 6
//persistent
const MSG_GROUP_NOTIFICATION = 7
const MSG_GROUP_IM = 8

//deprecated
const MSG_PEER_ACK = 9
const MSG_INPUTING = 10

//deprecated
const MSG_SUBSCRIBE_ONLINE_STATE = 11
const MSG_ONLINE_STATE = 12

const MSG_PING = 13
const MSG_PONG = 14
const MSG_AUTH_TOKEN = 15
const MSG_LOGIN_POINT = 16
const MSG_RT = 17
const MSG_ENTER_ROOM = 18
const MSG_LEAVE_ROOM = 19
const MSG_ROOM_IM = 20
//persistent
const MSG_SYSTEM = 21

const MSG_UNREAD_COUNT = 22

//persistent, deprecated
const MSG_CUSTOMER_SERVICE_ = 23

//persistent
const MSG_CUSTOMER = 24 //顾客->客服
const MSG_CUSTOMER_SUPPORT = 25 //客服->顾客


const MSG_VOIP_CONTROL = 64

//平台号
const PLATFORM_IOS = 1
const PLATFORM_ANDROID = 2
const PLATFORM_WEB = 3

const DEFAULT_VERSION = 1

var message_descriptions map[int]string = make(map[int]string)

type MessageCreator func()IMessage
var message_creators map[int]MessageCreator = make(map[int]MessageCreator)

type VersionMessageCreator func()IVersionMessage
var vmessage_creators map[int]VersionMessageCreator = make(map[int]VersionMessageCreator)


func init() {
	message_creators[MSG_AUTH] = func()IMessage {return new(Authentication)}
	message_creators[MSG_ACK] = func()IMessage{return new(MessageACK)}
	message_creators[MSG_GROUP_NOTIFICATION] = func()IMessage{return new(GroupNotification)}

	message_creators[MSG_PEER_ACK] = func()IMessage{return new(MessagePeerACK)}
	message_creators[MSG_INPUTING] = func()IMessage{return new(MessageInputing)}
	message_creators[MSG_SUBSCRIBE_ONLINE_STATE] = func()IMessage{return new(MessageSubscribeState)}
	message_creators[MSG_ONLINE_STATE] = func()IMessage{return new(MessageOnlineState)}
	message_creators[MSG_AUTH_TOKEN] = func()IMessage{return new(AuthenticationToken)}

	message_creators[MSG_LOGIN_POINT] = func()IMessage{return new(LoginPoint)}
	message_creators[MSG_RT] = func()IMessage{return new(RTMessage)}
	message_creators[MSG_ENTER_ROOM] = func()IMessage{return new(Room)}
	message_creators[MSG_LEAVE_ROOM] = func()IMessage{return new(Room)}
	message_creators[MSG_ROOM_IM] = func()IMessage{return &RoomMessage{new(RTMessage)}}
	message_creators[MSG_SYSTEM] = func()IMessage{return new(SystemMessage)}
	message_creators[MSG_UNREAD_COUNT] = func()IMessage{return new(MessageUnreadCount)}
	message_creators[MSG_CUSTOMER_SERVICE_] = func()IMessage{return new(CustomerServiceMessage)}

	message_creators[MSG_CUSTOMER] = func()IMessage{return new(CustomerMessage)}
	message_creators[MSG_CUSTOMER_SUPPORT] = func()IMessage{return new(CustomerMessage)}

	message_creators[MSG_VOIP_CONTROL] = func()IMessage{return new(VOIPControl)}

	vmessage_creators[MSG_GROUP_IM] = func()IVersionMessage{return new(IMMessage)}
	vmessage_creators[MSG_IM] = func()IVersionMessage{return new(IMMessage)}

	vmessage_creators[MSG_AUTH_STATUS] = func()IVersionMessage{return new(AuthenticationStatus)}

	message_descriptions[MSG_AUTH] = "MSG_AUTH"
	message_descriptions[MSG_AUTH_STATUS] = "MSG_AUTH_STATUS"
	message_descriptions[MSG_IM] = "MSG_IM"
	message_descriptions[MSG_ACK] = "MSG_ACK"
	message_descriptions[MSG_GROUP_NOTIFICATION] = "MSG_GROUP_NOTIFICATION"
	message_descriptions[MSG_GROUP_IM] = "MSG_GROUP_IM"
	message_descriptions[MSG_PEER_ACK] = "MSG_PEER_ACK"
	message_descriptions[MSG_INPUTING] = "MSG_INPUTING"
	message_descriptions[MSG_SUBSCRIBE_ONLINE_STATE] = "MSG_SUBSCRIBE_ONLINE_STATE"
	message_descriptions[MSG_ONLINE_STATE] = "MSG_ONLINE_STATE"
	message_descriptions[MSG_PING] = "MSG_PING"
	message_descriptions[MSG_PONG] = "MSG_PONG"
	message_descriptions[MSG_AUTH_TOKEN] = "MSG_AUTH_TOKEN"
	message_descriptions[MSG_LOGIN_POINT] = "MSG_LOGIN_POINT"
	message_descriptions[MSG_RT] = "MSG_RT"
	message_descriptions[MSG_ENTER_ROOM] = "MSG_ENTER_ROOM"
	message_descriptions[MSG_LEAVE_ROOM] = "MSG_LEAVE_ROOM"
	message_descriptions[MSG_ROOM_IM] = "MSG_ROOM_IM"
	message_descriptions[MSG_SYSTEM] = "MSG_SYSTEM"
	message_descriptions[MSG_UNREAD_COUNT] = "MSG_UNREAD_COUNT"
	message_descriptions[MSG_CUSTOMER_SERVICE_] = "MSG_CUSTOMER_SERVICE"
	message_descriptions[MSG_CUSTOMER] = "MSG_CUSTOMER"
	message_descriptions[MSG_CUSTOMER_SUPPORT] = "MSG_CUSTOMER_SUPPORT"
	message_descriptions[MSG_VOIP_CONTROL] = "MSG_VOIP_CONTROL"
}

type Command int
func (cmd Command) String() string {
	c := int(cmd)
	if desc, ok := message_descriptions[c]; ok {
		return desc
	} else {
		return fmt.Sprintf("%d", c)
	}
}

type IMessage interface {
	ToData() []byte
	FromData(buff []byte) bool
}

type IVersionMessage interface {
	ToData(version int) []byte
	FromData(version int, buff []byte) bool
}

type Message struct {
	cmd  int
	seq  int
	version int
	
	body interface{}
}

func (message *Message) ToData() []byte {
	if message.body != nil {
		if m, ok := message.body.(IMessage); ok {
			return m.ToData()
		}
		if m, ok := message.body.(IVersionMessage); ok {
			return m.ToData(message.version)
		}
		return nil
	} else {
		return nil
	}
}

func (message *Message) FromData(buff []byte) bool {
	cmd := message.cmd
	if creator, ok := message_creators[cmd]; ok {
		c := creator()
		r := c.FromData(buff)
		message.body = c
		return r
	}
	if creator, ok := vmessage_creators[cmd]; ok {
		c := creator()
		r := c.FromData(message.version, buff)
		message.body = c
		return r
	}

	return len(buff) == 0
}

type RTMessage struct {
	sender    int64
	receiver  int64
	content   string
}
func (message *RTMessage) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, message.sender)
	binary.Write(buffer, binary.BigEndian, message.receiver)
	buffer.Write([]byte(message.content))
	buf := buffer.Bytes()
	return buf
}

func (rt *RTMessage) FromData(buff []byte) bool {
	if len(buff) < 16 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &rt.sender)
	binary.Read(buffer, binary.BigEndian, &rt.receiver)
	rt.content = string(buff[16:])
	return true
}


type IMMessage struct {
	sender    int64
	receiver  int64
	timestamp int32
	msgid     int32
	content   string
}


func (message *IMMessage) ToDataV0() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, message.sender)
	binary.Write(buffer, binary.BigEndian, message.receiver)
	binary.Write(buffer, binary.BigEndian, message.msgid)
	buffer.Write([]byte(message.content))
	buf := buffer.Bytes()
	return buf
}

func (im *IMMessage) FromDataV0(buff []byte) bool {
	if len(buff) < 20 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &im.sender)
	binary.Read(buffer, binary.BigEndian, &im.receiver)
	binary.Read(buffer, binary.BigEndian, &im.msgid)
	im.content = string(buff[20:])
	return true
}


func (message *IMMessage) ToDataV1() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, message.sender)
	binary.Write(buffer, binary.BigEndian, message.receiver)
	binary.Write(buffer, binary.BigEndian, message.timestamp)
	binary.Write(buffer, binary.BigEndian, message.msgid)
	buffer.Write([]byte(message.content))
	buf := buffer.Bytes()
	return buf
}

func (im *IMMessage) FromDataV1(buff []byte) bool {
	if len(buff) < 24 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &im.sender)
	binary.Read(buffer, binary.BigEndian, &im.receiver)
	binary.Read(buffer, binary.BigEndian, &im.timestamp)
	binary.Read(buffer, binary.BigEndian, &im.msgid)
	im.content = string(buff[24:])
	return true
}


func (im *IMMessage) ToData(version int) []byte {
	if version == 0 {
		return im.ToDataV0()
	} else {
		return im.ToDataV1()
	}
}

func (im *IMMessage) FromData(version int, buff []byte) bool {
	if version == 0 {
		return im.FromDataV0(buff)
	} else {
		return im.FromDataV1(buff)
	}
}


type Authentication struct {
	uid         int64
}

func (auth *Authentication) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, auth.uid)
	buf := buffer.Bytes()
	return buf
}

func (auth *Authentication) FromData(buff []byte) bool {
	if len(buff) < 8 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &auth.uid)
	return true
}

type AuthenticationToken struct {
	token       string
	platform_id int8
	device_id   string
}


func (auth *AuthenticationToken) ToData() []byte {
	var l int8

	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, auth.platform_id)

	l = int8(len(auth.token))
	binary.Write(buffer, binary.BigEndian, l)
	buffer.Write([]byte(auth.token))

	l = int8(len(auth.device_id))
	binary.Write(buffer, binary.BigEndian, l)
	buffer.Write([]byte(auth.device_id))

	buf := buffer.Bytes()
	return buf
}

func (auth *AuthenticationToken) FromData(buff []byte) bool {
	var l int8
	if (len(buff) <= 3) {
		return false
	}
	auth.platform_id = int8(buff[0])

	buffer := bytes.NewBuffer(buff[1:])

	binary.Read(buffer, binary.BigEndian, &l)
	if int(l) > buffer.Len() || int(l) < 0 {
		return false
	}
	token := make([]byte, l)
	buffer.Read(token)

	binary.Read(buffer, binary.BigEndian, &l)
	if int(l) > buffer.Len() || int(l) < 0 {
		return false
	}
	device_id := make([]byte, l)
	buffer.Read(device_id)

	auth.token = string(token)
	auth.device_id = string(device_id)
	return true
}

type AuthenticationStatus struct {
	status int32
	ip int32 //兼容版本0
}

func (auth *AuthenticationStatus) ToData(version int) []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, auth.status)
	if version == 0 {
		binary.Write(buffer, binary.BigEndian, auth.ip)
	}
	buf := buffer.Bytes()
	return buf
}

func (auth *AuthenticationStatus) FromData(version int, buff []byte) bool {
	if len(buff) < 4 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &auth.status)
	if version == 0 {
		if len(buff) < 8 {
			return false
		}
		binary.Read(buffer, binary.BigEndian, &auth.ip)
	}
	return true
}


type LoginPoint struct {
	up_timestamp      int32
	platform_id       int8
	device_id         string
}

func (point *LoginPoint) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, point.up_timestamp)
	binary.Write(buffer, binary.BigEndian, point.platform_id)
	buffer.Write([]byte(point.device_id))
	buf := buffer.Bytes()
	return buf
}

func (point *LoginPoint) FromData(buff []byte) bool {
	if len(buff) <= 5 {
		return false
	}

	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &point.up_timestamp)
	binary.Read(buffer, binary.BigEndian, &point.platform_id)
	point.device_id = string(buff[5:])
	return true
}


type MessageACK struct {
	seq int32
}

func (ack *MessageACK) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, ack.seq)
	buf := buffer.Bytes()
	return buf
}

func (ack *MessageACK) FromData(buff []byte) bool {
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &ack.seq)
	return true
}

type MessagePeerACK struct {
	sender   int64
	receiver int64
	msgid    int32
}

func (ack *MessagePeerACK) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, ack.sender)
	binary.Write(buffer, binary.BigEndian, ack.receiver)
	binary.Write(buffer, binary.BigEndian, ack.msgid)
	buf := buffer.Bytes()
	return buf
}

func (ack *MessagePeerACK) FromData(buff []byte) bool {
	if len(buff) < 20 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &ack.sender)
	binary.Read(buffer, binary.BigEndian, &ack.receiver)
	binary.Read(buffer, binary.BigEndian, &ack.msgid)
	return true
}

type MessageInputing struct {
	sender   int64
	receiver int64
}

func (inputing *MessageInputing) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, inputing.sender)
	binary.Write(buffer, binary.BigEndian, inputing.receiver)
	buf := buffer.Bytes()
	return buf
}

func (inputing *MessageInputing) FromData(buff []byte) bool {
	if len(buff) < 16 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &inputing.sender)
	binary.Read(buffer, binary.BigEndian, &inputing.receiver)
	return true
}

type MessageUnreadCount struct {
	count int32
}

func (u *MessageUnreadCount) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, u.count)
	buf := buffer.Bytes()
	return buf
}

func (u *MessageUnreadCount) FromData(buff []byte) bool {
	if len(buff) < 4 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &u.count)
	return true
}

type SystemMessage struct {
	notification string
}

func (sys *SystemMessage) ToData() []byte {
	return []byte(sys.notification)
}

func (sys *SystemMessage) FromData(buff []byte) bool {
	sys.notification = string(buff)
	return true
}

type CustomerServiceMessage struct {
	customer_id    int64//普通用户id
	sender    int64
	receiver  int64
	timestamp int32
	content   string
}

func (cs *CustomerServiceMessage) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, cs.customer_id)
	binary.Write(buffer, binary.BigEndian, cs.sender)
	binary.Write(buffer, binary.BigEndian, cs.receiver)
	binary.Write(buffer, binary.BigEndian, cs.timestamp)
	buffer.Write([]byte(cs.content))
	buf := buffer.Bytes()
	return buf
}

func (cs *CustomerServiceMessage) FromData(buff []byte) bool {
	if len(buff) < 20 {
		return false
	}
	buffer := bytes.NewBuffer(buff)

	if len(buff) >= 28 {
		//兼容旧数据
		binary.Read(buffer, binary.BigEndian, &cs.customer_id)
	}

	binary.Read(buffer, binary.BigEndian, &cs.sender)
	binary.Read(buffer, binary.BigEndian, &cs.receiver)
	binary.Read(buffer, binary.BigEndian, &cs.timestamp)

	if len(buff) >= 28 {
		cs.content = string(buff[28:])
	} else {
		cs.content = string(buff[20:])
	}
	return true
}

type CustomerMessage struct {
	customer_appid int64//顾客id所在appid
	customer_id    int64//顾客id
	store_id	   int64
	seller_id	   int64
	timestamp	   int32
	content		   string
}

func (cs *CustomerMessage) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, cs.customer_appid)
	binary.Write(buffer, binary.BigEndian, cs.customer_id)
	binary.Write(buffer, binary.BigEndian, cs.store_id)
	binary.Write(buffer, binary.BigEndian, cs.seller_id)
	binary.Write(buffer, binary.BigEndian, cs.timestamp)
	buffer.Write([]byte(cs.content))
	buf := buffer.Bytes()
	return buf
}

func (cs *CustomerMessage) FromData(buff []byte) bool {
	if len(buff) < 36 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &cs.customer_appid)
	binary.Read(buffer, binary.BigEndian, &cs.customer_id)
	binary.Read(buffer, binary.BigEndian, &cs.store_id)
	binary.Read(buffer, binary.BigEndian, &cs.seller_id)
	binary.Read(buffer, binary.BigEndian, &cs.timestamp)

	cs.content = string(buff[36:])

	return true
}


type GroupNotification struct {
	notification string
}

func (notification *GroupNotification) ToData() []byte {
	return []byte(notification.notification)
}
 
func (notification *GroupNotification) FromData(buff []byte) bool {
	notification.notification = string(buff)
	return true
}

type Room int64
func (room *Room) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, int64(*room))
	buf := buffer.Bytes()
	return buf	
}

func (room *Room) FromData(buff []byte) bool {
	if len(buff) < 8 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, (*int64)(room))
	return true
}

func (room *Room) RoomID() int64 {
	return int64(*room)
}

type RoomMessage struct {
	*RTMessage
}

type MessageOnlineState struct {
	sender int64
	online int32
}

func (state *MessageOnlineState) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, state.sender)
	binary.Write(buffer, binary.BigEndian, state.online)
	buf := buffer.Bytes()
	return buf
}

func (state *MessageOnlineState) FromData(buff []byte) bool {
	if len(buff) < 12 {
		return false
	}
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &state.sender)
	binary.Read(buffer, binary.BigEndian, &state.online)
	return true
}



type MessageSubscribeState struct {
	uids []int64
}


func (sub *MessageSubscribeState) ToData() []byte {
	return nil
}

func (sub *MessageSubscribeState) FromData(buff []byte) bool {
	buffer := bytes.NewBuffer(buff)
	var count int32
	binary.Read(buffer, binary.BigEndian, &count)
	sub.uids = make([]int64, count)
	for i := 0; i < int(count); i++ {
		binary.Read(buffer, binary.BigEndian, &sub.uids[i])
	}
	return true
}


type VOIPControl struct {
	sender   int64
	receiver int64
	content  []byte
}

func (ctl *VOIPControl) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, ctl.sender)
	binary.Write(buffer, binary.BigEndian, ctl.receiver)
	buffer.Write([]byte(ctl.content))
	buf := buffer.Bytes()
	return buf
}

func (ctl *VOIPControl) FromData(buff []byte) bool {
	if len(buff) <= 16 {
		return false
	}

	buffer := bytes.NewBuffer(buff[:16])
	binary.Read(buffer, binary.BigEndian, &ctl.sender)
	binary.Read(buffer, binary.BigEndian, &ctl.receiver)
	ctl.content = buff[16:]
	return true
}


type AppUserID struct {
	appid    int64
	uid      int64
}

func (id *AppUserID) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, id.appid)
	binary.Write(buffer, binary.BigEndian, id.uid)
	buf := buffer.Bytes()
	return buf
}

func (id *AppUserID) FromData(buff []byte) bool {
	if len(buff) < 16 {
		return false
	}

	buffer := bytes.NewBuffer(buff)	
	binary.Read(buffer, binary.BigEndian, &id.appid)
	binary.Read(buffer, binary.BigEndian, &id.uid)

	return true
}

type AppRoomID struct {
	appid    int64
	room_id      int64
}

func (id *AppRoomID) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, id.appid)
	binary.Write(buffer, binary.BigEndian, id.room_id)
	buf := buffer.Bytes()
	return buf
}

func (id *AppRoomID) FromData(buff []byte) bool {
	if len(buff) < 16 {
		return false
	}

	buffer := bytes.NewBuffer(buff)	
	binary.Read(buffer, binary.BigEndian, &id.appid)
	binary.Read(buffer, binary.BigEndian, &id.room_id)

	return true
}

type AppGroupMemberID struct {
	appid  int64
	gid    int64
	uid    int64
}

func (id *AppGroupMemberID) ToData() []byte {
	buffer := new(bytes.Buffer)
	binary.Write(buffer, binary.BigEndian, id.appid)
	binary.Write(buffer, binary.BigEndian, id.gid)
	binary.Write(buffer, binary.BigEndian, id.uid)
	buf := buffer.Bytes()
	return buf
}

func (id *AppGroupMemberID) FromData(buff []byte) bool {
	if len(buff) < 24 {
		return false
	}

	buffer := bytes.NewBuffer(buff)	
	binary.Read(buffer, binary.BigEndian, &id.appid)
	binary.Read(buffer, binary.BigEndian, &id.gid)
	binary.Read(buffer, binary.BigEndian, &id.uid)

	return true
}


func WriteHeader(len int32, seq int32, cmd byte, version byte, buffer io.Writer) {
	binary.Write(buffer, binary.BigEndian, len)
	binary.Write(buffer, binary.BigEndian, seq)
	t := []byte{cmd, byte(version), 0, 0}
	buffer.Write(t)
}

func ReadHeader(buff []byte) (int, int, int, int) {
	var length int32
	var seq int32
	buffer := bytes.NewBuffer(buff)
	binary.Read(buffer, binary.BigEndian, &length)
	binary.Read(buffer, binary.BigEndian, &seq)
	cmd, _ := buffer.ReadByte()
	version, _ := buffer.ReadByte()
	return int(length), int(seq), int(cmd), int(version)
}

func WriteMessage(w *bytes.Buffer, msg *Message) {
	body := msg.ToData()
	WriteHeader(int32(len(body)), int32(msg.seq), byte(msg.cmd), byte(msg.version), w)
	w.Write(body)
}

func SendMessage(conn io.Writer, msg *Message) error {
	buffer := new(bytes.Buffer)
	WriteMessage(buffer, msg)
	buf := buffer.Bytes()
	n, err := conn.Write(buf)
	if err != nil {
		log.Info("sock write error:", err)
		return err
	}
	if n != len(buf) {
		log.Infof("write less:%d %d", n, len(buf))
		return errors.New("write less")
	}
	return nil
}

func ReceiveMessage(conn io.Reader) *Message {
	buff := make([]byte, 12)
	_, err := io.ReadFull(conn, buff)
	if err != nil {
		log.Info("sock read error:", err)
		return nil
	}

	length, seq, cmd, version := ReadHeader(buff)
	if length < 0 || length >= 32*1024 {
		log.Info("invalid len:", length)
		return nil
	}
	buff = make([]byte, length)
	_, err = io.ReadFull(conn, buff)
	if err != nil {
		log.Info("sock read error:", err)
		return nil
	}

	message := new(Message)
	message.cmd = cmd
	message.seq = seq
	message.version = version
	if !message.FromData(buff) {
		log.Warning("parse error")
		return nil
	}
	return message
}

//消息大小限制在1M
func ReceiveStorageMessage(conn io.Reader) *Message {
	buff := make([]byte, 12)
	_, err := io.ReadFull(conn, buff)
	if err != nil {
		log.Info("sock read error:", err)
		return nil
	}

	length, seq, cmd, version := ReadHeader(buff)
	if length < 0 || length >= 1024*1024 {
		log.Info("invalid len:", length)
		return nil
	}
	buff = make([]byte, length)
	_, err = io.ReadFull(conn, buff)
	if err != nil {
		log.Info("sock read error:", err)
		return nil
	}

	message := new(Message)
	message.cmd = cmd
	message.seq = seq
	message.version = version
	if !message.FromData(buff) {
		log.Warning("parse error")
		return nil
	}
	return message
}