Merge pull request #1455 from nspcc-dev/get_invocation_counter

core: remove error from runtime.GetInvocationCounter

pkg/core/interop/context.go

@@ -35,7 +35,6 @@ type Context struct {
 	DAO           *dao.Cached
 	Notifications []state.NotificationEvent
 	Log           *zap.Logger
-	Invocations   map[util.Uint160]int
 	VM            *vm.VM
 	Functions     [][]Function
 }
@@ -53,7 +52,6 @@ func NewContext(trigger trigger.Type, bc blockchainer.Blockchainer, d dao.DAO, n
 		DAO:           dao,
 		Notifications: nes,
 		Log:           log,
-		Invocations:   make(map[util.Uint160]int),
 		// Functions is a slice of slices of interops sorted by ID.
 		Functions: [][]Function{},
 	}

pkg/core/interop/contract/call.go

@@ -67,7 +67,7 @@ func CallExInternal(ic *interop.Context, cs *state.Contract,
 	}
 
 	u := cs.ScriptHash()
-	ic.Invocations[u]++
+	ic.VM.Invocations[u]++
 	ic.VM.LoadScriptWithHash(cs.Script, u, ic.VM.Context().GetCallFlags()&f)
 	var isNative bool
 	for i := range ic.Natives {

pkg/core/interop/runtime/util.go

@@ -58,9 +58,11 @@ func GetNotifications(ic *interop.Context) error {
 
 // GetInvocationCounter returns how many times current contract was invoked during current tx execution.
 func GetInvocationCounter(ic *interop.Context) error {
-	count, ok := ic.Invocations[ic.VM.GetCurrentScriptHash()]
+	currentScriptHash := ic.VM.GetCurrentScriptHash()
+	count, ok := ic.VM.Invocations[currentScriptHash]
 	if !ok {
-		return errors.New("current contract wasn't invoked from others")
+		count = 1
+		ic.VM.Invocations[currentScriptHash] = count
 	}
 	ic.VM.Estack().PushVal(count)
 	return nil

pkg/core/interop_system_test.go

@@ -296,11 +296,13 @@ func TestRuntimeGetInvocationCounter(t *testing.T) {
 	v, ic, chain := createVM(t)
 	defer chain.Close()
 
-	ic.Invocations[hash.Hash160([]byte{2})] = 42
+	ic.VM.Invocations[hash.Hash160([]byte{2})] = 42
 
-	t.Run("Zero", func(t *testing.T) {
+	t.Run("No invocations", func(t *testing.T) {
 		v.LoadScript([]byte{1})
-		require.Error(t, runtime.GetInvocationCounter(ic))
+		// do not return an error in this case.
+		require.NoError(t, runtime.GetInvocationCounter(ic))
+		require.EqualValues(t, 1, v.Estack().Pop().BigInt().Int64())
 	})
 	t.Run("NonZero", func(t *testing.T) {
 		v.LoadScript([]byte{2})

pkg/vm/vm.go

@@ -80,6 +80,9 @@ type VM struct {
 	SyscallHandler func(v *VM, id uint32) error
 
 	trigger trigger.Type
+
+	// Invocations is a script invocation counter.
+	Invocations map[util.Uint160]int
 }
 
 // New returns a new VM object ready to load AVM bytecode scripts.
@@ -96,6 +99,7 @@ func NewWithTrigger(t trigger.Type) *VM {
 		trigger: t,
 
 		SyscallHandler: defaultSyscallHandler,
+		Invocations:    make(map[util.Uint160]int),
 	}
 
 	vm.estack = vm.newItemStack("evaluation")
@@ -1225,7 +1229,7 @@ func (v *VM) execute(ctx *Context, op opcode.Opcode, parameter []byte) (err erro
 		v.checkInvocationStackSize()
 		// Note: jump offset must be calculated regarding to new context,
 		// but it is cloned and thus has the same script and instruction pointer.
-		v.Call(ctx, v.getJumpOffset(ctx, parameter))
+		v.call(ctx, v.getJumpOffset(ctx, parameter))
 
 	case opcode.CALLA:
 		ptr := v.estack.Pop().Item().(*stackitem.Pointer)
@@ -1233,7 +1237,7 @@ func (v *VM) execute(ctx *Context, op opcode.Opcode, parameter []byte) (err erro
 			panic("invalid script in pointer")
 		}
 
-		v.Call(ctx, ptr.Position())
+		v.call(ctx, ptr.Position())
 
 	case opcode.SYSCALL:
 		interopID := GetInteropID(parameter)
@@ -1455,8 +1459,17 @@ func (v *VM) Jump(ctx *Context, offset int) {
 }
 
 // Call calls method by offset. It is similar to Jump but also
-// pushes new context to the invocation state
+// pushes new context to the invocation stack and increments
+// invocation counter for the corresponding context script hash.
 func (v *VM) Call(ctx *Context, offset int) {
+	v.call(ctx, offset)
+	v.Invocations[ctx.ScriptHash()]++
+}
+
+// call is an internal representation of Call, which does not
+// affect the invocation counter and is only being used by vm
+// package.
+func (v *VM) call(ctx *Context, offset int) {
 	newCtx := ctx.Copy()
 	newCtx.CheckReturn = false
 	newCtx.local = nil