object.go

// Copyright ©2017 The go-hep Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package rbase

import (
	"reflect"

	"go-hep.org/x/hep/groot/rbytes"
	"go-hep.org/x/hep/groot/root"
	"go-hep.org/x/hep/groot/rtypes"
	"go-hep.org/x/hep/groot/rvers"
)

type Object struct {
	ID   uint32
	Bits uint32
}

func NewObject() *Object {
	return &Object{ID: 0x0, Bits: 0x3000000}
}

func (*Object) Class() string {
	return "TObject"
}

func (obj *Object) UID() uint32 {
	return obj.ID
}

func (*Object) RVersion() int {
	return rvers.Object
}

func (obj *Object) SetID(id uint32)           { obj.ID = id }
func (obj *Object) SetBit(bit uint32)         { obj.Bits |= bit & kBitMask }
func (obj *Object) ResetBit(bit uint32)       { obj.Bits &= ^(bit & kBitMask) }
func (obj *Object) SetBits(bits uint32)       { obj.Bits = bits }
func (obj *Object) TestBits(bits uint32) bool { return obj.Bits&bits != 0 }

func (obj *Object) UnmarshalROOT(r *rbytes.RBuffer) error {
	r.SkipVersion("")
	obj.ID = r.ReadU32()
	obj.Bits = r.ReadU32()
	obj.Bits |= kIsOnHeap
	if obj.TestBits(kIsReferenced) {
		_ = r.ReadU16()
	}
	return r.Err()
}

func (obj *Object) MarshalROOT(w *rbytes.WBuffer) (int, error) {
	n := w.Pos()
	w.WriteU16(uint16(obj.RVersion()))
	switch {
	case obj.TestBits(kIsReferenced):
		uid := obj.ID & 0xffffff
		w.WriteU32(uid)
		w.WriteU32(obj.Bits)
		w.WriteU16(0) // FIXME(sbinet): implement referenced objects.
		// panic(fmt.Errorf("rbase: writing referenced objects are not supported"))
	default:
		w.WriteU32(obj.ID)
		w.WriteU32(obj.Bits)
	}

	return int(w.Pos() - n), w.Err()
}

func init() {
	f := func() reflect.Value {
		o := &Object{}
		return reflect.ValueOf(o)
	}
	rtypes.Factory.Add("TObject", f)
}

var (
	_ root.Object        = (*Object)(nil)
	_ root.UIDer         = (*Object)(nil)
	_ rbytes.Marshaler   = (*Object)(nil)
	_ rbytes.Unmarshaler = (*Object)(nil)
)