89 lines
2.0 KiB
Go
89 lines
2.0 KiB
Go
package pgproto3
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/json"
|
|
"errors"
|
|
|
|
"github.com/jackc/pgx/v5/internal/pgio"
|
|
)
|
|
|
|
type Describe struct {
|
|
ObjectType byte // 'S' = prepared statement, 'P' = portal
|
|
Name string
|
|
}
|
|
|
|
// Frontend identifies this message as sendable by a PostgreSQL frontend.
|
|
func (*Describe) 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 *Describe) Decode(src []byte) error {
|
|
if len(src) < 2 {
|
|
return &invalidMessageFormatErr{messageType: "Describe"}
|
|
}
|
|
|
|
dst.ObjectType = src[0]
|
|
rp := 1
|
|
|
|
idx := bytes.IndexByte(src[rp:], 0)
|
|
if idx != len(src[rp:])-1 {
|
|
return &invalidMessageFormatErr{messageType: "Describe"}
|
|
}
|
|
|
|
dst.Name = string(src[rp : len(src)-1])
|
|
|
|
return nil
|
|
}
|
|
|
|
// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
|
|
func (src *Describe) Encode(dst []byte) []byte {
|
|
dst = append(dst, 'D')
|
|
sp := len(dst)
|
|
dst = pgio.AppendInt32(dst, -1)
|
|
|
|
dst = append(dst, src.ObjectType)
|
|
dst = append(dst, src.Name...)
|
|
dst = append(dst, 0)
|
|
|
|
pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))
|
|
|
|
return dst
|
|
}
|
|
|
|
// MarshalJSON implements encoding/json.Marshaler.
|
|
func (src Describe) MarshalJSON() ([]byte, error) {
|
|
return json.Marshal(struct {
|
|
Type string
|
|
ObjectType string
|
|
Name string
|
|
}{
|
|
Type: "Describe",
|
|
ObjectType: string(src.ObjectType),
|
|
Name: src.Name,
|
|
})
|
|
}
|
|
|
|
// UnmarshalJSON implements encoding/json.Unmarshaler.
|
|
func (dst *Describe) UnmarshalJSON(data []byte) error {
|
|
// Ignore null, like in the main JSON package.
|
|
if string(data) == "null" {
|
|
return nil
|
|
}
|
|
|
|
var msg struct {
|
|
ObjectType string
|
|
Name string
|
|
}
|
|
if err := json.Unmarshal(data, &msg); err != nil {
|
|
return err
|
|
}
|
|
if len(msg.ObjectType) != 1 {
|
|
return errors.New("invalid length for Describe.ObjectType")
|
|
}
|
|
|
|
dst.ObjectType = byte(msg.ObjectType[0])
|
|
dst.Name = msg.Name
|
|
return nil
|
|
}
|