package znet import ( "bytes" "encoding/binary" "errors" "github.com/aceld/zinx/utils" "github.com/aceld/zinx/ziface" ) var defaultHeaderLen uint32 = 8 //DataPack 封包拆包类实例,暂时不需要成员 type DataPack struct{} //NewDataPack 封包拆包实例初始化方法 func NewDataPack() ziface.Packet { return &DataPack{} } //GetHeadLen 获取包头长度方法 func (dp *DataPack) GetHeadLen() uint32 { //ID uint32(4字节) + DataLen uint32(4字节) return defaultHeaderLen } //Pack 封包方法(压缩数据) func (dp *DataPack) Pack(msg ziface.IMessage) ([]byte, error) { //创建一个存放bytes字节的缓冲 dataBuff := bytes.NewBuffer([]byte{}) //写dataLen if err := binary.Write(dataBuff, binary.LittleEndian, msg.GetDataLen()); err != nil { return nil, err } //写msgID if err := binary.Write(dataBuff, binary.LittleEndian, msg.GetMsgID()); err != nil { return nil, err } //写data数据 if err := binary.Write(dataBuff, binary.LittleEndian, msg.GetData()); err != nil { return nil, err } return dataBuff.Bytes(), nil } //Unpack 拆包方法(解压数据) func (dp *DataPack) Unpack(binaryData []byte) (ziface.IMessage, error) { //创建一个从输入二进制数据的ioReader dataBuff := bytes.NewReader(binaryData) //只解压head的信息,得到dataLen和msgID msg := &Message{} //读dataLen if err := binary.Read(dataBuff, binary.LittleEndian, &msg.DataLen); err != nil { return nil, err } //读msgID if err := binary.Read(dataBuff, binary.LittleEndian, &msg.ID); err != nil { return nil, err } //判断dataLen的长度是否超出我们允许的最大包长度 if utils.GlobalObject.MaxPacketSize > 0 && msg.DataLen > utils.GlobalObject.MaxPacketSize { return nil, errors.New("too large msg data received") } //这里只需要把head的数据拆包出来就可以了,然后再通过head的长度,再从conn读取一次数据 return msg, nil }