frostfs-node/pkg/morph/event/opcodes.go
Pavel Karpy 5d791a4366 [#825] morph/event: Fix commentary
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-09-15 18:07:50 +03:00

50 lines
1.1 KiB
Go

package event
import (
"fmt"
"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
)
// Op is wrapper over Neo VM's opcode
// and its parameter.
type Op struct {
code opcode.Opcode
param []byte
}
// Code returns Neo VM opcode.
func (o Op) Code() opcode.Opcode {
return o.code
}
// Param returns parameter of wrapped
// Neo VM opcode.
func (o Op) Param() []byte {
return o.param
}
// BytesFromOpcode tries to retrieve bytes from Op.
func BytesFromOpcode(op Op) ([]byte, error) {
switch code := op.Code(); code {
case opcode.PUSHDATA1, opcode.PUSHDATA2, opcode.PUSHDATA4:
return op.Param(), nil
default:
return nil, fmt.Errorf("unexpected ByteArray opcode %s", code)
}
}
// IntFromOpcode tries to retrieve int from Op.
func IntFromOpcode(op Op) (int64, error) {
switch code := op.Code(); {
case code == opcode.PUSHM1:
return -1, nil
case code >= opcode.PUSH0 && code <= opcode.PUSH16:
return int64(code - opcode.PUSH0), nil
case code <= opcode.PUSHINT256:
return bigint.FromBytes(op.Param()).Int64(), nil
default:
return 0, fmt.Errorf("unexpected INT opcode %s", code)
}
}