序

本文只有钻研一下dubbo-go的DubboPackage

DubboPackage

dubbo-go-v1.4.2/protocol/dubbo/codec.go

//CallType call typetype CallType int32const (    // CT_UNKNOWN unknown call type    CT_UNKNOWN CallType = 0    // CT_OneWay call one way    CT_OneWay CallType = 1    // CT_TwoWay call in request/response    CT_TwoWay CallType = 2)// SequenceType ...type SequenceType int64// DubboPackage ...type DubboPackage struct {    Header  hessian.DubboHeader    Service hessian.Service    Body    interface{}    Err     error}
  • DubboPackage定义了Header、Service、Body、Err属性

Marshal

dubbo-go-v1.4.2/protocol/dubbo/codec.go

// Marshal ...func (p *DubboPackage) Marshal() (*bytes.Buffer, error) {    codec := hessian.NewHessianCodec(nil)    pkg, err := codec.Write(p.Service, p.Header, p.Body)    if err != nil {        return nil, perrors.WithStack(err)    }    return bytes.NewBuffer(pkg), nil}
  • Marshal办法通过hessian.NewHessianCodec(nil)创立codec，之后执行bytes.NewBuffer(pkg)

Unmarshal

dubbo-go-v1.4.2/protocol/dubbo/codec.go

// Unmarshal ...func (p *DubboPackage) Unmarshal(buf *bytes.Buffer, opts ...interface{}) error {    // fix issue https://github.com/apache/dubbo-go/issues/380    bufLen := buf.Len()    if bufLen < hessian.HEADER_LENGTH {        return perrors.WithStack(hessian.ErrHeaderNotEnough)    }    codec := hessian.NewHessianCodec(bufio.NewReaderSize(buf, bufLen))    // read header    err := codec.ReadHeader(&p.Header)    if err != nil {        return perrors.WithStack(err)    }    if len(opts) != 0 { // for client        client, ok := opts[0].(*Client)        if !ok {            return perrors.Errorf("opts[0] is not of type *Client")        }        if p.Header.Type&hessian.PackageRequest != 0x00 {            // size of this array must be '7'            // https://github.com/apache/dubbo-go-hessian2/blob/master/request.go#L272            p.Body = make([]interface{}, 7)        } else {            pendingRsp, ok := client.pendingResponses.Load(SequenceType(p.Header.ID))            if !ok {                return perrors.Errorf("client.GetPendingResponse(%v) = nil", p.Header.ID)            }            p.Body = &hessian.Response{RspObj: pendingRsp.(*PendingResponse).response.reply}        }    }    // read body    err = codec.ReadBody(p.Body)    return perrors.WithStack(err)}
  • Unmarshal办法先通过hessian.NewHessianCodec(bufio.NewReaderSize(buf, bufLen))创立codec，而后执行codec.ReadHeader(&p.Header)读取header，最初通过codec.ReadBody(p.Body)读取body

PendingResponse

dubbo-go-v1.4.2/protocol/dubbo/codec.go

// PendingResponse ...type PendingResponse struct {    seq       uint64    err       error    start     time.Time    readStart time.Time    callback  common.AsyncCallback    response  *Response    done      chan struct{}}// NewPendingResponse ...func NewPendingResponse() *PendingResponse {    return &PendingResponse{        start:    time.Now(),        response: &Response{},        done:     make(chan struct{}),    }}
  • NewPendingResponse实例化了PendingResponse

GetCallResponse

dubbo-go-v1.4.2/protocol/dubbo/codec.go

// GetCallResponse ...func (r PendingResponse) GetCallResponse() common.CallbackResponse {    return AsyncCallbackResponse{        Cause:     r.err,        Start:     r.start,        ReadStart: r.readStart,        Reply:     r.response,    }}
  • GetCallResponse办法实例化AsyncCallbackResponse

小结

DubboPackage定义了Header、Service、Body、Err属性；codec.go提供了Marshal、Unmarshal办法用于读写DubboPackage

doc

  • codec