68 lines
1.3 KiB
Go
68 lines
1.3 KiB
Go
package vm
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import (
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"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
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)
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// Slot is a fixed-size slice of stack items.
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type Slot struct {
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storage []stackitem.Item
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refs *refCounter
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}
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// newSlot returns new slot with the provided reference counter.
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func newSlot(refs *refCounter) *Slot {
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return &Slot{
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refs: refs,
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}
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}
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// init sets static slot size to n. It is intended to be used only by INITSSLOT.
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func (s *Slot) init(n int) {
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if s.storage != nil {
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panic("already initialized")
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}
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s.storage = make([]stackitem.Item, n)
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}
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func (v *VM) newSlot(n int) *Slot {
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s := newSlot(&v.refs)
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s.init(n)
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return s
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}
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// Set sets i-th storage slot.
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func (s *Slot) Set(i int, item stackitem.Item) {
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if s.storage[i] == item {
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return
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}
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old := s.storage[i]
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s.storage[i] = item
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if old != nil {
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s.refs.Remove(old)
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}
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s.refs.Add(item)
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}
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// Get returns item contained in i-th slot.
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func (s *Slot) Get(i int) stackitem.Item {
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if item := s.storage[i]; item != nil {
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return item
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}
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return stackitem.Null{}
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}
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// Clear removes all slot variables from reference counter.
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func (s *Slot) Clear() {
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for _, item := range s.storage {
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s.refs.Remove(item)
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}
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}
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// Size returns slot size.
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func (s *Slot) Size() int {
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if s.storage == nil {
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panic("not initialized")
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}
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return len(s.storage)
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}
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