native: emit Designation event on role update

pkg/core/native/designate.go

@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"math"
+	"math/big"
 	"sort"
 	"sync/atomic"
 
@@ -57,6 +58,9 @@ const (
 
 	// maxNodeCount is the maximum number of nodes to set the role for.
 	maxNodeCount = 32
+
+	// DesignationEventName is the name of a designation event.
+	DesignationEventName = "Designation"
 )
 
 // Various errors.
@@ -88,9 +92,13 @@ func newDesignate(p2pSigExtensionsEnabled bool) *Designate {
 	desc = newDescriptor("designateAsRole", smartcontract.VoidType,
 		manifest.NewParameter("role", smartcontract.IntegerType),
 		manifest.NewParameter("nodes", smartcontract.ArrayType))
-	md = newMethodAndPrice(s.designateAsRole, 1<<15, callflag.States)
+	md = newMethodAndPrice(s.designateAsRole, 1<<15, callflag.States|callflag.AllowNotify)
 	s.AddMethod(md, desc)
 
+	s.AddEvent(DesignationEventName,
+		manifest.NewParameter("Role", smartcontract.IntegerType),
+		manifest.NewParameter("BlockIndex", smartcontract.IntegerType))
+
 	return s
 }
 
@@ -319,7 +327,20 @@ func (s *Designate) DesignateAsRole(ic *interop.Context, r noderoles.Role, pubs
 	}
 	sort.Sort(pubs)
 	s.rolesChangedFlag.Store(true)
-	return ic.DAO.PutStorageItem(s.ID, key, NodeList(pubs).Bytes())
+	err := ic.DAO.PutStorageItem(s.ID, key, NodeList(pubs).Bytes())
+	if err != nil {
+		return err
+	}
+
+	ic.Notifications = append(ic.Notifications, state.NotificationEvent{
+		ScriptHash: s.Hash,
+		Name:       DesignationEventName,
+		Item: stackitem.NewArray([]stackitem.Item{
+			stackitem.NewBigInteger(big.NewInt(int64(r))),
+			stackitem.NewBigInteger(big.NewInt(int64(ic.Block.Index))),
+		}),
+	})
+	return nil
 }
 
 func (s *Designate) getRole(item stackitem.Item) (noderoles.Role, bool) {

pkg/core/native_designate_test.go

@@ -58,8 +58,18 @@ func (bc *Blockchain) setNodesByRole(t *testing.T, ok bool, r noderoles.Role, no
 	require.Equal(t, 1, len(aer))
 	if ok {
 		require.Equal(t, vm.HaltState, aer[0].VMState)
+		require.Equal(t, 1, len(aer[0].Events))
+
+		ev := aer[0].Events[0]
+		require.Equal(t, bc.contracts.Designate.Hash, ev.ScriptHash)
+		require.Equal(t, native.DesignationEventName, ev.Name)
+		require.Equal(t, []stackitem.Item{
+			stackitem.Make(int64(r)),
+			stackitem.Make(bc.BlockHeight()),
+		}, ev.Item.Value().([]stackitem.Item))
 	} else {
 		require.Equal(t, vm.FaultState, aer[0].VMState)
+		require.Equal(t, 0, len(aer[0].Events))
 	}
 }
 

pkg/interop/native/roles/roles.go

@@ -34,5 +34,5 @@ func GetDesignatedByRole(r Role, height uint32) []interop.PublicKey {
 // DesignateAsRole represents `designateAsRole` method of RoleManagement native contract.
 func DesignateAsRole(r Role, pubs []interop.PublicKey) {
 	contract.Call(interop.Hash160(Hash), "designateAsRole",
-		contract.States, r, pubs)
+		contract.States|contract.AllowNotify, r, pubs)
 }