neoneo-go/pkg/vm/ref_counter.go

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package vm
import (
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
// refCounter represents a reference counter for the VM.
type refCounter int
func newRefCounter() *refCounter {
return new(refCounter)
}
// Add adds an item to the reference counter.
func (r *refCounter) Add(item stackitem.Item) {
if r == nil {
return
}
*r++
switch t := item.(type) {
case *stackitem.Array:
if t.IncRC() == 1 {
for _, it := range t.Value().([]stackitem.Item) {
r.Add(it)
}
}
case *stackitem.Struct:
if t.IncRC() == 1 {
for _, it := range t.Value().([]stackitem.Item) {
r.Add(it)
}
}
case *stackitem.Map:
if t.IncRC() == 1 {
elems := t.Value().([]stackitem.MapElement)
for i := range elems {
r.Add(elems[i].Key)
r.Add(elems[i].Value)
}
}
}
}
// Remove removes an item from the reference counter.
func (r *refCounter) Remove(item stackitem.Item) {
if r == nil {
return
}
*r--
switch t := item.(type) {
case *stackitem.Array:
if t.DecRC() == 0 {
for _, it := range t.Value().([]stackitem.Item) {
r.Remove(it)
}
}
case *stackitem.Struct:
if t.DecRC() == 0 {
for _, it := range t.Value().([]stackitem.Item) {
r.Remove(it)
}
}
case *stackitem.Map:
if t.DecRC() == 0 {
elems := t.Value().([]stackitem.MapElement)
for i := range elems {
r.Remove(elems[i].Key)
r.Remove(elems[i].Value)
}
}
}
}