neo-go/pkg/vm/interop.go
Evgenii Stratonikov b0d07c3031 vm: make Iterator interface public
There is nothing wrong with iterators being implemented in other parts
of code (e.g. Storage.Find). In this case type assertions can
prevent bugs at compile-time.
2020-05-27 11:40:46 +03:00

251 lines
6.3 KiB
Go

package vm
import (
"crypto/sha256"
"encoding/binary"
"errors"
"fmt"
"sort"
)
// InteropFunc allows to hook into the VM.
type InteropFunc func(vm *VM) error
// InteropFuncPrice represents an interop function with a price.
type InteropFuncPrice struct {
Func InteropFunc
Price int
}
// interopIDFuncPrice adds an ID to the InteropFuncPrice.
type interopIDFuncPrice struct {
ID uint32
InteropFuncPrice
}
// InteropGetterFunc is a function that returns an interop function-price
// structure by the given interop ID.
type InteropGetterFunc func(uint32) *InteropFuncPrice
var defaultVMInterops = []interopIDFuncPrice{
{InteropNameToID([]byte("Neo.Runtime.Log")),
InteropFuncPrice{runtimeLog, 1}},
{InteropNameToID([]byte("Neo.Runtime.Notify")),
InteropFuncPrice{runtimeNotify, 1}},
{InteropNameToID([]byte("Neo.Runtime.Serialize")),
InteropFuncPrice{RuntimeSerialize, 1}},
{InteropNameToID([]byte("System.Runtime.Serialize")),
InteropFuncPrice{RuntimeSerialize, 1}},
{InteropNameToID([]byte("Neo.Runtime.Deserialize")),
InteropFuncPrice{RuntimeDeserialize, 1}},
{InteropNameToID([]byte("System.Runtime.Deserialize")),
InteropFuncPrice{RuntimeDeserialize, 1}},
{InteropNameToID([]byte("Neo.Enumerator.Create")),
InteropFuncPrice{EnumeratorCreate, 1}},
{InteropNameToID([]byte("Neo.Enumerator.Next")),
InteropFuncPrice{EnumeratorNext, 1}},
{InteropNameToID([]byte("Neo.Enumerator.Concat")),
InteropFuncPrice{EnumeratorConcat, 1}},
{InteropNameToID([]byte("Neo.Enumerator.Value")),
InteropFuncPrice{EnumeratorValue, 1}},
{InteropNameToID([]byte("Neo.Iterator.Create")),
InteropFuncPrice{IteratorCreate, 1}},
{InteropNameToID([]byte("Neo.Iterator.Concat")),
InteropFuncPrice{IteratorConcat, 1}},
{InteropNameToID([]byte("Neo.Iterator.Key")),
InteropFuncPrice{IteratorKey, 1}},
{InteropNameToID([]byte("Neo.Iterator.Keys")),
InteropFuncPrice{IteratorKeys, 1}},
{InteropNameToID([]byte("Neo.Iterator.Values")),
InteropFuncPrice{IteratorValues, 1}},
}
func getDefaultVMInterop(id uint32) *InteropFuncPrice {
n := sort.Search(len(defaultVMInterops), func(i int) bool {
return defaultVMInterops[i].ID >= id
})
if n < len(defaultVMInterops) && defaultVMInterops[n].ID == id {
return &defaultVMInterops[n].InteropFuncPrice
}
return nil
}
// InteropNameToID returns an identificator of the method based on its name.
func InteropNameToID(name []byte) uint32 {
h := sha256.Sum256(name)
return binary.LittleEndian.Uint32(h[:4])
}
// runtimeLog handles the syscall "Neo.Runtime.Log" for printing and logging stuff.
func runtimeLog(vm *VM) error {
item := vm.Estack().Pop()
fmt.Printf("NEO-GO-VM (log) > %s\n", item.Value())
return nil
}
// runtimeNotify handles the syscall "Neo.Runtime.Notify" for printing and logging stuff.
func runtimeNotify(vm *VM) error {
item := vm.Estack().Pop()
fmt.Printf("NEO-GO-VM (notify) > %s\n", item.Value())
return nil
}
// RuntimeSerialize handles syscalls System.Runtime.Serialize and Neo.Runtime.Serialize.
func RuntimeSerialize(vm *VM) error {
item := vm.Estack().Pop()
data, err := SerializeItem(item.value)
if err != nil {
return err
} else if len(data) > MaxItemSize {
return errors.New("too big item")
}
vm.Estack().PushVal(data)
return nil
}
// RuntimeDeserialize handles syscalls System.Runtime.Deserialize and Neo.Runtime.Deserialize.
func RuntimeDeserialize(vm *VM) error {
data := vm.Estack().Pop().Bytes()
item, err := DeserializeItem(data)
if err != nil {
return err
}
vm.Estack().Push(&Element{value: item})
return nil
}
// init sorts the global defaultVMInterops value.
func init() {
sort.Slice(defaultVMInterops, func(i, j int) bool {
return defaultVMInterops[i].ID < defaultVMInterops[j].ID
})
}
// EnumeratorCreate handles syscall Neo.Enumerator.Create.
func EnumeratorCreate(v *VM) error {
data := v.Estack().Pop().Array()
v.Estack().Push(&Element{
value: NewInteropItem(&arrayWrapper{
index: -1,
value: data,
}),
})
return nil
}
// EnumeratorNext handles syscall Neo.Enumerator.Next.
func EnumeratorNext(v *VM) error {
iop := v.Estack().Pop().Interop()
arr := iop.value.(enumerator)
v.Estack().PushVal(arr.Next())
return nil
}
// EnumeratorValue handles syscall Neo.Enumerator.Value.
func EnumeratorValue(v *VM) error {
iop := v.Estack().Pop().Interop()
arr := iop.value.(enumerator)
v.Estack().Push(&Element{value: arr.Value()})
return nil
}
// EnumeratorConcat handles syscall Neo.Enumerator.Concat.
func EnumeratorConcat(v *VM) error {
iop1 := v.Estack().Pop().Interop()
arr1 := iop1.value.(enumerator)
iop2 := v.Estack().Pop().Interop()
arr2 := iop2.value.(enumerator)
v.Estack().Push(&Element{
value: NewInteropItem(&concatEnum{
current: arr1,
second: arr2,
}),
})
return nil
}
// IteratorCreate handles syscall Neo.Iterator.Create.
func IteratorCreate(v *VM) error {
data := v.Estack().Pop()
var item StackItem
switch t := data.value.(type) {
case *ArrayItem, *StructItem:
item = NewInteropItem(&arrayWrapper{
index: -1,
value: t.Value().([]StackItem),
})
case *MapItem:
item = NewMapIterator(t)
default:
return errors.New("non-iterable type")
}
v.Estack().Push(&Element{value: item})
return nil
}
// NewMapIterator returns new interop item containing iterator over m.
func NewMapIterator(m *MapItem) *InteropItem {
return NewInteropItem(&mapWrapper{
index: -1,
m: m.value,
})
}
// IteratorConcat handles syscall Neo.Iterator.Concat.
func IteratorConcat(v *VM) error {
iop1 := v.Estack().Pop().Interop()
iter1 := iop1.value.(Iterator)
iop2 := v.Estack().Pop().Interop()
iter2 := iop2.value.(Iterator)
v.Estack().Push(&Element{value: NewInteropItem(
&concatIter{
current: iter1,
second: iter2,
},
)})
return nil
}
// IteratorKey handles syscall Neo.Iterator.Key.
func IteratorKey(v *VM) error {
iop := v.estack.Pop().Interop()
iter := iop.value.(Iterator)
v.Estack().Push(&Element{value: iter.Key()})
return nil
}
// IteratorKeys handles syscall Neo.Iterator.Keys.
func IteratorKeys(v *VM) error {
iop := v.estack.Pop().Interop()
iter := iop.value.(Iterator)
v.Estack().Push(&Element{value: NewInteropItem(
&keysWrapper{iter},
)})
return nil
}
// IteratorValues handles syscall Neo.Iterator.Values.
func IteratorValues(v *VM) error {
iop := v.estack.Pop().Interop()
iter := iop.value.(Iterator)
v.Estack().Push(&Element{value: NewInteropItem(
&valuesWrapper{iter},
)})
return nil
}