query.go

package pgproto3

import (
	"bytes"
	"regexp"
	"strings"

	"github.com/jackc/pgio"
)

type Query struct {
	String string `json:"string" yaml:"string"`
}

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

// 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 *Query) Decode(src []byte) error {
	//println("Query.Decode")
	i := bytes.IndexByte(src, 0)
	if i != len(src)-1 {
		return &invalidMessageFormatErr{messageType: "Query"}
	}

	dst.String = string(src[:i])
	// fmt.Println("dst.String BEFORE-- ", dst.String)
	dst.String = strings.ReplaceAll(dst.String, "\n", " ")
	// fmt.Println("dst.String AFTER-- ", dst.String)
	// Use a regular expression to reduce multiple spaces to a single space
	re := regexp.MustCompile(`\s+`)
	dst.String = re.ReplaceAllString(dst.String, " ")

	return nil
}

// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
func (src *Query) Encode(dst []byte) []byte {
	//println("Query.Encode")
	dst = append(dst, 'Q')
	dst = pgio.AppendInt32(dst, int32(4+len(src.String)+1))

	dst = append(dst, src.String...)
	dst = append(dst, 0)

	return dst
}

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