package state import ( "errors" "math/big" "unicode/utf8" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" ) // OracleRequest represents an oracle request. type OracleRequest struct { OriginalTxID util.Uint256 GasForResponse uint64 URL string Filter *string CallbackContract util.Uint160 CallbackMethod string UserData []byte } // ToStackItem implements stackitem.Convertible interface. It never returns an // error. func (o *OracleRequest) ToStackItem() (stackitem.Item, error) { filter := stackitem.Item(stackitem.Null{}) if o.Filter != nil { filter = stackitem.Make(*o.Filter) } return stackitem.NewArray([]stackitem.Item{ stackitem.NewByteArray(o.OriginalTxID.BytesBE()), stackitem.NewBigInteger(new(big.Int).SetUint64(o.GasForResponse)), stackitem.Make(o.URL), filter, stackitem.NewByteArray(o.CallbackContract.BytesBE()), stackitem.Make(o.CallbackMethod), stackitem.NewByteArray(o.UserData), }), nil } // FromStackItem implements stackitem.Convertible interface. func (o *OracleRequest) FromStackItem(it stackitem.Item) error { arr, ok := it.Value().([]stackitem.Item) if !ok || len(arr) < 7 { return errors.New("not an array of needed length") } bs, err := arr[0].TryBytes() if err != nil { return err } o.OriginalTxID, err = util.Uint256DecodeBytesBE(bs) if err != nil { return err } gas, err := arr[1].TryInteger() if err != nil { return err } o.GasForResponse = gas.Uint64() s, isNull, ok := itemToString(arr[2]) if !ok || isNull { return errors.New("invalid URL") } o.URL = s s, isNull, ok = itemToString(arr[3]) if !ok { return errors.New("invalid filter") } else if !isNull { filter := s o.Filter = &filter } bs, err = arr[4].TryBytes() if err != nil { return err } o.CallbackContract, err = util.Uint160DecodeBytesBE(bs) if err != nil { return err } o.CallbackMethod, isNull, ok = itemToString(arr[5]) if !ok || isNull { return errors.New("invalid callback method") } o.UserData, err = arr[6].TryBytes() return err } func itemToString(it stackitem.Item) (string, bool, bool) { _, ok := it.(stackitem.Null) if ok { return "", true, true } bs, err := it.TryBytes() if err != nil || !utf8.Valid(bs) { return "", false, false } return string(bs), false, true }