neoneo-go/pkg/core/interop/storage/find.go

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package storage
import "github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
// Storage iterator options.
const (
FindDefault = 0
FindKeysOnly = 1 << 0
FindRemovePrefix = 1 << 1
FindValuesOnly = 1 << 2
FindAll = FindDefault | FindKeysOnly | FindRemovePrefix | FindValuesOnly
)
type Iterator struct {
m []stackitem.MapElement
opts int64
index int
}
func NewIterator(m *stackitem.Map, opts int64) *Iterator {
return &Iterator{
m: m.Value().([]stackitem.MapElement),
opts: opts,
index: -1,
}
}
func (s *Iterator) Next() bool {
if s.index < len(s.m) {
s.index += 1
}
return s.index < len(s.m)
}
func (s *Iterator) Value() stackitem.Item {
key := s.m[s.index].Key.Value().([]byte)
if s.opts&FindRemovePrefix != 0 {
key = key[1:]
}
if s.opts&FindKeysOnly != 0 {
return stackitem.NewByteArray(key)
}
if s.opts&FindValuesOnly != 0 {
return s.m[s.index].Value
}
return stackitem.NewStruct([]stackitem.Item{
stackitem.NewByteArray(key),
s.m[s.index].Value,
})
}