GoToSocial/vendor/github.com/jackc/pgx/v5/pgproto3/parameter_description.go

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package pgproto3
import (
"bytes"
"encoding/binary"
"encoding/json"
"errors"
"math"
"github.com/jackc/pgx/v5/internal/pgio"
)
type ParameterDescription struct {
ParameterOIDs []uint32
}
// Backend identifies this message as sendable by the PostgreSQL backend.
func (*ParameterDescription) Backend() {}
// 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 *ParameterDescription) Decode(src []byte) error {
buf := bytes.NewBuffer(src)
if buf.Len() < 2 {
return &invalidMessageFormatErr{messageType: "ParameterDescription"}
}
// Reported parameter count will be incorrect when number of args is greater than uint16
buf.Next(2)
// Instead infer parameter count by remaining size of message
parameterCount := buf.Len() / 4
*dst = ParameterDescription{ParameterOIDs: make([]uint32, parameterCount)}
for i := 0; i < parameterCount; i++ {
dst.ParameterOIDs[i] = binary.BigEndian.Uint32(buf.Next(4))
}
return nil
}
// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
func (src *ParameterDescription) Encode(dst []byte) ([]byte, error) {
dst, sp := beginMessage(dst, 't')
if len(src.ParameterOIDs) > math.MaxUint16 {
return nil, errors.New("too many parameter oids")
}
dst = pgio.AppendUint16(dst, uint16(len(src.ParameterOIDs)))
for _, oid := range src.ParameterOIDs {
dst = pgio.AppendUint32(dst, oid)
}
return finishMessage(dst, sp)
}
// MarshalJSON implements encoding/json.Marshaler.
func (src ParameterDescription) MarshalJSON() ([]byte, error) {
return json.Marshal(struct {
Type string
ParameterOIDs []uint32
}{
Type: "ParameterDescription",
ParameterOIDs: src.ParameterOIDs,
})
}