vm: extend interops to contain price

The same way C# node does.

pkg/vm/tests/vm_test.go

@@ -45,9 +45,9 @@ func vmAndCompile(t *testing.T, src string) *vm.VM {
 	vm := vm.New(vm.ModeMute)
 
 	storePlugin := newStoragePlugin()
-	vm.RegisterInteropFunc("Neo.Storage.Get", storePlugin.Get)
+	vm.RegisterInteropFunc("Neo.Storage.Get", storePlugin.Get, 1)
-	vm.RegisterInteropFunc("Neo.Storage.Put", storePlugin.Put)
+	vm.RegisterInteropFunc("Neo.Storage.Put", storePlugin.Put, 1)
-	vm.RegisterInteropFunc("Neo.Storage.GetContext", storePlugin.GetContext)
+	vm.RegisterInteropFunc("Neo.Storage.GetContext", storePlugin.GetContext, 1)
 
 	b, err := compiler.Compile(strings.NewReader(src), &compiler.Options{})
 	if err != nil {

pkg/vm/vm.go

@@ -33,7 +33,7 @@ type VM struct {
 	state State
 
 	// registered interop hooks.
-	interop map[string]InteropFunc
+	interop map[string]InteropFuncPrice
 
 	// callback to get scripts.
 	getScript func(util.Uint160) []byte
@@ -48,10 +48,16 @@ type VM struct {
 	checkhash []byte
 }
 
+// InteropFuncPrice represents an interop function with a price.
+type InteropFuncPrice struct {
+	Func  InteropFunc
+	Price int
+}
+
 // New returns a new VM object ready to load .avm bytecode scripts.
 func New(mode Mode) *VM {
 	vm := &VM{
-		interop:   make(map[string]InteropFunc),
+		interop:   make(map[string]InteropFuncPrice),
 		getScript: nil,
 		state:     haltState,
 		istack:    NewStack("invocation"),
@@ -63,15 +69,15 @@ func New(mode Mode) *VM {
 	}
 
 	// Register native interop hooks.
-	vm.RegisterInteropFunc("Neo.Runtime.Log", runtimeLog)
+	vm.RegisterInteropFunc("Neo.Runtime.Log", runtimeLog, 1)
-	vm.RegisterInteropFunc("Neo.Runtime.Notify", runtimeNotify)
+	vm.RegisterInteropFunc("Neo.Runtime.Notify", runtimeNotify, 1)
 
 	return vm
 }
 
 // RegisterInteropFunc will register the given InteropFunc to the VM.
-func (v *VM) RegisterInteropFunc(name string, f InteropFunc) {
+func (v *VM) RegisterInteropFunc(name string, f InteropFunc, price int) {
-	v.interop[name] = f
+	v.interop[name] = InteropFuncPrice{f, price}
 }
 
 // Estack will return the evaluation stack so interop hooks can utilize this.
@@ -850,7 +856,7 @@ func (v *VM) execute(ctx *Context, op Instruction) {
 		if !ok {
 			panic(fmt.Sprintf("interop hook (%s) not registered", api))
 		}
-		if err := ifunc(v); err != nil {
+		if err := ifunc.Func(v); err != nil {
 			panic(fmt.Sprintf("failed to invoke syscall: %s", err))
 		}
 

pkg/vm/vm_test.go

@@ -18,7 +18,7 @@ func TestInteropHook(t *testing.T) {
 	v.RegisterInteropFunc("foo", func(evm *VM) error {
 		evm.Estack().PushVal(1)
 		return nil
-	})
+	}, 1)
 
 	buf := new(bytes.Buffer)
 	EmitSyscall(buf, "foo")
@@ -33,7 +33,7 @@ func TestInteropHook(t *testing.T) {
 func TestRegisterInterop(t *testing.T) {
 	v := New(ModeMute)
 	currRegistered := len(v.interop)
-	v.RegisterInteropFunc("foo", func(evm *VM) error { return nil })
+	v.RegisterInteropFunc("foo", func(evm *VM) error { return nil }, 1)
 	assert.Equal(t, currRegistered+1, len(v.interop))
 	_, ok := v.interop["foo"]
 	assert.Equal(t, true, ok)