copy_out_response.go

package pgproto3

import (
	"bytes"
	"encoding/binary"

	"github.com/jackc/pgio"
)

type CopyOutResponse struct {
	OverallFormat     byte     `json:"overall_format" yaml:"overall_format"`
	ColumnFormatCodes []uint16 `json:"column_format_codes" yaml:"column_format_codes"`
}

func (*CopyOutResponse) Backend() {}

// func (*CopyOutResponse) Backend() *CopyOutResponse {
// 	return &CopyOutResponse{}

// }

// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
// type identifier and 4 byte message length.
func (dst *CopyOutResponse) Decode(src []byte) error {
	//println("CopyOutResponse.Decode")
	buf := bytes.NewBuffer(src)

	if buf.Len() < 3 {
		return &invalidMessageFormatErr{messageType: "CopyOutResponse"}
	}

	overallFormat := buf.Next(1)[0]

	columnCount := int(binary.BigEndian.Uint16(buf.Next(2)))
	if buf.Len() != columnCount*2 {
		return &invalidMessageFormatErr{messageType: "CopyOutResponse"}
	}

	columnFormatCodes := make([]uint16, columnCount)
	for i := 0; i < columnCount; i++ {
		columnFormatCodes[i] = binary.BigEndian.Uint16(buf.Next(2))
	}

	*dst = CopyOutResponse{OverallFormat: overallFormat, ColumnFormatCodes: columnFormatCodes}

	return nil
}

// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
func (src *CopyOutResponse) Encode(dst []byte) []byte {
	//println("CopyOutResponse.Encode")
	dst = append(dst, 'H')
	sp := len(dst)
	dst = pgio.AppendInt32(dst, -1)

	dst = append(dst, src.OverallFormat)

	dst = pgio.AppendUint16(dst, uint16(len(src.ColumnFormatCodes)))
	for _, fc := range src.ColumnFormatCodes {
		dst = pgio.AppendUint16(dst, fc)
	}

	pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))

	return dst
}

// MarshalJSON implements encoding/json.Marshaler.
// func (src CopyOutResponse) MarshalJSON() ([]byte, error) {
// 	return json.Marshal(struct {
// 		Type              string
// 		ColumnFormatCodes []uint16
// 	}{
// 		Type:              "CopyOutResponse",
// 		ColumnFormatCodes: src.ColumnFormatCodes,
// 	})
// }

// // UnmarshalJSON implements encoding/json.Unmarshaler.
// func (dst *CopyOutResponse) UnmarshalJSON(data []byte) error {
// 	// Ignore null, like in the main JSON package.
// 	if string(data) == "null" {
// 		return nil
// 	}

// 	var msg struct {
// 		OverallFormat     string
// 		ColumnFormatCodes []uint16
// 	}
// 	if err := json.Unmarshal(data, &msg); err != nil {
// 		return err
// 	}

// 	if len(msg.OverallFormat) != 1 {
// 		return errors.New("invalid length for CopyOutResponse.OverallFormat")
// 	}

// 	dst.OverallFormat = msg.OverallFormat[0]
// 	dst.ColumnFormatCodes = msg.ColumnFormatCodes
// 	return nil
// }