package pgproto3 import ( "bytes" "encoding/binary" "encoding/json" "github.com/jackc/pgx/v5/internal/pgio" ) const ( TextFormat = 0 BinaryFormat = 1 ) type FieldDescription struct { Name []byte TableOID uint32 TableAttributeNumber uint16 DataTypeOID uint32 DataTypeSize int16 TypeModifier int32 Format int16 } // MarshalJSON implements encoding/json.Marshaler. func (fd FieldDescription) MarshalJSON() ([]byte, error) { return json.Marshal(struct { Name string TableOID uint32 TableAttributeNumber uint16 DataTypeOID uint32 DataTypeSize int16 TypeModifier int32 Format int16 }{ Name: string(fd.Name), TableOID: fd.TableOID, TableAttributeNumber: fd.TableAttributeNumber, DataTypeOID: fd.DataTypeOID, DataTypeSize: fd.DataTypeSize, TypeModifier: fd.TypeModifier, Format: fd.Format, }) } type RowDescription struct { Fields []FieldDescription } // Backend identifies this message as sendable by the PostgreSQL backend. func (*RowDescription) 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 *RowDescription) Decode(src []byte) error { if len(src) < 2 { return &invalidMessageFormatErr{messageType: "RowDescription"} } fieldCount := int(binary.BigEndian.Uint16(src)) rp := 2 dst.Fields = dst.Fields[0:0] for i := 0; i < fieldCount; i++ { var fd FieldDescription idx := bytes.IndexByte(src[rp:], 0) if idx < 0 { return &invalidMessageFormatErr{messageType: "RowDescription"} } fd.Name = src[rp : rp+idx] rp += idx + 1 // Since buf.Next() doesn't return an error if we hit the end of the buffer // check Len ahead of time if len(src[rp:]) < 18 { return &invalidMessageFormatErr{messageType: "RowDescription"} } fd.TableOID = binary.BigEndian.Uint32(src[rp:]) rp += 4 fd.TableAttributeNumber = binary.BigEndian.Uint16(src[rp:]) rp += 2 fd.DataTypeOID = binary.BigEndian.Uint32(src[rp:]) rp += 4 fd.DataTypeSize = int16(binary.BigEndian.Uint16(src[rp:])) rp += 2 fd.TypeModifier = int32(binary.BigEndian.Uint32(src[rp:])) rp += 4 fd.Format = int16(binary.BigEndian.Uint16(src[rp:])) rp += 2 dst.Fields = append(dst.Fields, fd) } return nil } // Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length. func (src *RowDescription) Encode(dst []byte) []byte { dst = append(dst, 'T') sp := len(dst) dst = pgio.AppendInt32(dst, -1) dst = pgio.AppendUint16(dst, uint16(len(src.Fields))) for _, fd := range src.Fields { dst = append(dst, fd.Name...) dst = append(dst, 0) dst = pgio.AppendUint32(dst, fd.TableOID) dst = pgio.AppendUint16(dst, fd.TableAttributeNumber) dst = pgio.AppendUint32(dst, fd.DataTypeOID) dst = pgio.AppendInt16(dst, fd.DataTypeSize) dst = pgio.AppendInt32(dst, fd.TypeModifier) dst = pgio.AppendInt16(dst, fd.Format) } pgio.SetInt32(dst[sp:], int32(len(dst[sp:]))) return dst } // MarshalJSON implements encoding/json.Marshaler. func (src RowDescription) MarshalJSON() ([]byte, error) { return json.Marshal(struct { Type string Fields []FieldDescription }{ Type: "RowDescription", Fields: src.Fields, }) } // UnmarshalJSON implements encoding/json.Unmarshaler. func (dst *RowDescription) UnmarshalJSON(data []byte) error { var msg struct { Fields []struct { Name string TableOID uint32 TableAttributeNumber uint16 DataTypeOID uint32 DataTypeSize int16 TypeModifier int32 Format int16 } } if err := json.Unmarshal(data, &msg); err != nil { return err } dst.Fields = make([]FieldDescription, len(msg.Fields)) for n, field := range msg.Fields { dst.Fields[n] = FieldDescription{ Name: []byte(field.Name), TableOID: field.TableOID, TableAttributeNumber: field.TableAttributeNumber, DataTypeOID: field.DataTypeOID, DataTypeSize: field.DataTypeSize, TypeModifier: field.TypeModifier, Format: field.Format, } } return nil }