package pgproto3 import ( "bytes" "encoding/binary" "encoding/json" "errors" "fmt" "github.com/jackc/pgx/v5/internal/pgio" ) const ProtocolVersionNumber = 196608 // 3.0 type StartupMessage struct { ProtocolVersion uint32 Parameters map[string]string } // Frontend identifies this message as sendable by a PostgreSQL frontend. func (*StartupMessage) 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 *StartupMessage) Decode(src []byte) error { if len(src) < 4 { return errors.New("startup message too short") } dst.ProtocolVersion = binary.BigEndian.Uint32(src) rp := 4 if dst.ProtocolVersion != ProtocolVersionNumber { return fmt.Errorf("Bad startup message version number. Expected %d, got %d", ProtocolVersionNumber, dst.ProtocolVersion) } dst.Parameters = make(map[string]string) for { idx := bytes.IndexByte(src[rp:], 0) if idx < 0 { return &invalidMessageFormatErr{messageType: "StartupMesage"} } key := string(src[rp : rp+idx]) rp += idx + 1 idx = bytes.IndexByte(src[rp:], 0) if idx < 0 { return &invalidMessageFormatErr{messageType: "StartupMesage"} } value := string(src[rp : rp+idx]) rp += idx + 1 dst.Parameters[key] = value if len(src[rp:]) == 1 { if src[rp] != 0 { return fmt.Errorf("Bad startup message last byte. Expected 0, got %d", src[rp]) } break } } return nil } // Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length. func (src *StartupMessage) Encode(dst []byte) []byte { sp := len(dst) dst = pgio.AppendInt32(dst, -1) dst = pgio.AppendUint32(dst, src.ProtocolVersion) for k, v := range src.Parameters { dst = append(dst, k...) dst = append(dst, 0) dst = append(dst, v...) dst = append(dst, 0) } dst = append(dst, 0) pgio.SetInt32(dst[sp:], int32(len(dst[sp:]))) return dst } // MarshalJSON implements encoding/json.Marshaler. func (src StartupMessage) MarshalJSON() ([]byte, error) { return json.Marshal(struct { Type string ProtocolVersion uint32 Parameters map[string]string }{ Type: "StartupMessage", ProtocolVersion: src.ProtocolVersion, Parameters: src.Parameters, }) }