neoneo-go/pkg/vm/slot.go
Roman Khimov ae2395f55f vm: simplify (slot).Set code
Refcounter handles nil items just fine.
2022-05-17 16:26:22 +03:00

64 lines
1.3 KiB
Go

package vm
import (
"encoding/json"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
// slot is a fixed-size slice of stack items.
type slot []stackitem.Item
// init sets static slot size to n. It is intended to be used only by INITSSLOT.
func (s *slot) init(n int, rc *refCounter) {
if *s != nil {
panic("already initialized")
}
*s = make([]stackitem.Item, n)
*rc += refCounter(n) // Virtual "Null" elements.
}
// Set sets i-th storage slot.
func (s slot) Set(i int, item stackitem.Item, refs *refCounter) {
if s[i] == item {
return
}
refs.Remove(s[i])
s[i] = item
refs.Add(item)
}
// Get returns the item contained in the i-th slot.
func (s slot) Get(i int) stackitem.Item {
if item := s[i]; item != nil {
return item
}
return stackitem.Null{}
}
// ClearRefs removes all slot variables from the reference counter.
func (s slot) ClearRefs(refs *refCounter) {
for _, item := range s {
refs.Remove(item)
}
}
// Size returns the slot size.
func (s slot) Size() int {
if s == nil {
panic("not initialized")
}
return len(s)
}
// MarshalJSON implements the JSON marshalling interface.
func (s slot) MarshalJSON() ([]byte, error) {
arr := make([]json.RawMessage, len(s))
for i := range s {
data, err := stackitem.ToJSONWithTypes(s[i])
if err == nil {
arr[i] = data
}
}
return json.Marshal(arr)
}