聊聊kingbus的resp.go

Z时代
2024-01-10
分类：综合

序

本文主要研究一下kingbus的resp.go

writeOK

kingbus/mysql/resp.go

func (c *Conn) writeOK(r *gomysql.Result) error {
	if r == nil {
		r = &gomysql.Result{}
	}
	r.Status |= c.status
	data := make([]byte, 4, 32)
	data = append(data, gomysql.OK_HEADER)
	data = append(data, gomysql.PutLengthEncodedInt(r.AffectedRows)...)
	data = append(data, gomysql.PutLengthEncodedInt(r.InsertId)...)
	if c.capability&gomysql.CLIENT_PROTOCOL_41 > 0 {
		data = append(data, byte(r.Status), byte(r.Status>>8))
		data = append(data, 0, 0)
	}
	return c.WritePacket(data)
}

writeOK方法写入gomysql.OK_HEADER

writeError

kingbus/mysql/resp.go

func (c *Conn) writeError(e error) error {
	var m *gomysql.MyError
	var ok bool
	if m, ok = e.(*gomysql.MyError); !ok {
		m = gomysql.NewError(gomysql.ER_UNKNOWN_ERROR, e.Error())
	}
	data := make([]byte, 4, 16+len(m.Message))
	data = append(data, gomysql.ERR_HEADER)
	data = append(data, byte(m.Code), byte(m.Code>>8))
	if c.capability&gomysql.CLIENT_PROTOCOL_41 > 0 {
		data = append(data, "#")
		data = append(data, m.State...)
	}
	data = append(data, m.Message...)
	return c.WritePacket(data)
}

writeError方法写入gomysql.ERR_HEADER

writeEOF

kingbus/mysql/resp.go

func (c *Conn) writeEOF() error {
	data := make([]byte, 4, 9)
	data = append(data, gomysql.EOF_HEADER)
	if c.capability&gomysql.CLIENT_PROTOCOL_41 > 0 {
		data = append(data, 0, 0)
		data = append(data, byte(c.status), byte(c.status>>8))
	}
	return c.WritePacket(data)
}

writeEOF方法写入gomysql.EOF_HEADER

writeResultset

kingbus/mysql/resp.go

func (c *Conn) writeResultset(r *gomysql.Resultset) error {
	columnLen := gomysql.PutLengthEncodedInt(uint64(len(r.Fields)))
	data := make([]byte, 4, 1024)
	data = append(data, columnLen...)
	if err := c.WritePacket(data); err != nil {
		return err
	}
	for _, v := range r.Fields {
		data = data[0:4]
		data = append(data, v.Dump()...)
		if err := c.WritePacket(data); err != nil {
			return err
		}
	}
	if err := c.writeEOF(); err != nil {
		return err
	}
	for _, v := range r.RowDatas {
		data = data[0:4]
		data = append(data, v...)
		if err := c.WritePacket(data); err != nil {
			return err
		}
	}
	if err := c.writeEOF(); err != nil {
		return err
	}
	return nil
}

writeResultset方法写入columnLen、data、eof

writeFieldList

kingbus/mysql/resp.go

func (c *Conn) writeFieldList(fs []*gomysql.Field) error {
	data := make([]byte, 4, 1024)
	for _, v := range fs {
		data = data[0:4]
		data = append(data, v.Dump()...)
		if err := c.WritePacket(data); err != nil {
			return err
		}
	}
	if err := c.writeEOF(); err != nil {
		return err
	}
	return nil
}

writeFieldList方法写入data、eof

writeValue

kingbus/mysql/resp.go

func (c *Conn) writeValue(value interface{}) error {
	switch v := value.(type) {
	case noResponse:
		return nil
	case error:
		return c.writeError(v)
	case nil:
		return c.writeOK(nil)
	case *gomysql.Result:
		if v != nil && v.Resultset != nil {
			return c.writeResultset(v.Resultset)
		}
		return c.writeOK(v)
	case []*gomysql.Field:
		return c.writeFieldList(v)
	default:
		return fmt.Errorf("invalid response type %T", value)
	}
}