cancel_request.go

package pgproto3

import (
	"encoding/binary"
	"errors"

	"github.com/jackc/pgio"
)

const cancelRequestCode = 80877102

type CancelRequest struct {
	ProcessID uint32 `json:"process_id" yaml:"process_id"`
	SecretKey uint32 `json:"secret_key" yaml:"secret_key"`
}

// Frontend identifies this message as sendable by a PostgreSQL frontend.
func (*CancelRequest) Frontend() {}

func (dst *CancelRequest) Decode(src []byte) error {
	println("CancelRequest.Decode")
	if len(src) != 12 {
		return errors.New("bad cancel request size")
	}

	requestCode := binary.BigEndian.Uint32(src)

	if requestCode != cancelRequestCode {
		return errors.New("bad cancel request code")
	}

	dst.ProcessID = binary.BigEndian.Uint32(src[4:])
	dst.SecretKey = binary.BigEndian.Uint32(src[8:])

	return nil
}

// Encode encodes src into dst. dst will include the 4 byte message length.
func (src *CancelRequest) Encode(dst []byte) []byte {
	println("CancelRequest.Encode")
	dst = pgio.AppendInt32(dst, 16)
	dst = pgio.AppendInt32(dst, cancelRequestCode)
	dst = pgio.AppendUint32(dst, src.ProcessID)
	dst = pgio.AppendUint32(dst, src.SecretKey)
	return dst
}

// MarshalJSON implements encoding/json.Marshaler.
// func (src CancelRequest) MarshalJSON() ([]byte, error) {
// 	return json.Marshal(struct {
// 		Type      string
// 		ProcessID uint32
// 		SecretKey uint32
// 	}{
// 		Type:      "CancelRequest",
// 		ProcessID: src.ProcessID,
// 		SecretKey: src.SecretKey,
// 	})
// }