native: emit vote/candidate events

Follow neo-project/neo#2754.

pkg/core/native/native_neo.go

@@ -240,6 +240,18 @@ func newNEO(cfg config.ProtocolConfiguration) *NEO {
 	md = newMethodAndPrice(n.setRegisterPrice, 1<<15, callflag.States)
 	n.AddMethod(md, desc)
 
+	n.AddEvent("CandidateStateChanged",
+		manifest.NewParameter("pubkey", smartcontract.PublicKeyType),
+		manifest.NewParameter("registered", smartcontract.BoolType),
+		manifest.NewParameter("votes", smartcontract.IntegerType),
+	)
+	n.AddEvent("Vote",
+		manifest.NewParameter("account", smartcontract.Hash160Type),
+		manifest.NewParameter("from", smartcontract.PublicKeyType),
+		manifest.NewParameter("to", smartcontract.PublicKeyType),
+		manifest.NewParameter("amount", smartcontract.IntegerType),
+	)
+
 	return n
 }
 
@@ -733,6 +745,8 @@ func (n *NEO) registerCandidate(ic *interop.Context, args []stackitem.Item) stac
 
 // RegisterCandidateInternal registers pub as a new candidate.
 func (n *NEO) RegisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey) error {
+	var emitEvent = true
+
 	key := makeValidatorKey(pub)
 	si := ic.DAO.GetStorageItem(n.ID, key)
 	var c *candidate
@@ -740,9 +754,18 @@ func (n *NEO) RegisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey
 		c = &candidate{Registered: true}
 	} else {
 		c = new(candidate).FromBytes(si)
+		emitEvent = !c.Registered
 		c.Registered = true
 	}
-	return putConvertibleToDAO(n.ID, ic.DAO, key, c)
+	err := putConvertibleToDAO(n.ID, ic.DAO, key, c)
+	if emitEvent {
+		ic.AddNotification(n.Hash, "CandidateStateChanged", stackitem.NewArray([]stackitem.Item{
+			stackitem.NewByteArray(pub.Bytes()),
+			stackitem.NewBool(c.Registered),
+			stackitem.NewBigInteger(&c.Votes),
+		}))
+	}
+	return err
 }
 
 func (n *NEO) unregisterCandidate(ic *interop.Context, args []stackitem.Item) stackitem.Item {
@@ -759,6 +782,8 @@ func (n *NEO) unregisterCandidate(ic *interop.Context, args []stackitem.Item) st
 
 // UnregisterCandidateInternal unregisters pub as a candidate.
 func (n *NEO) UnregisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey) error {
+	var err error
+
 	key := makeValidatorKey(pub)
 	si := ic.DAO.GetStorageItem(n.ID, key)
 	if si == nil {
@@ -767,12 +792,20 @@ func (n *NEO) UnregisterCandidateInternal(ic *interop.Context, pub *keys.PublicK
 	cache := ic.DAO.GetRWCache(n.ID).(*NeoCache)
 	cache.validators = nil
 	c := new(candidate).FromBytes(si)
+	emitEvent := c.Registered
 	c.Registered = false
 	ok := n.dropCandidateIfZero(ic.DAO, cache, pub, c)
-	if ok {
+	if !ok {
-		return nil
+		err = putConvertibleToDAO(n.ID, ic.DAO, key, c)
 	}
-	return putConvertibleToDAO(n.ID, ic.DAO, key, c)
+	if emitEvent {
+		ic.AddNotification(n.Hash, "CandidateStateChanged", stackitem.NewArray([]stackitem.Item{
+			stackitem.NewByteArray(pub.Bytes()),
+			stackitem.NewBool(c.Registered),
+			stackitem.NewBigInteger(&c.Votes),
+		}))
+	}
+	return err
 }
 
 func (n *NEO) vote(ic *interop.Context, args []stackitem.Item) stackitem.Item {
@@ -834,17 +867,33 @@ func (n *NEO) VoteInternal(ic *interop.Context, h util.Uint160, pub *keys.Public
 	if err := n.ModifyAccountVotes(acc, ic.DAO, new(big.Int).Neg(&acc.Balance), false); err != nil {
 		return err
 	}
+	oldVote := acc.VoteTo
 	acc.VoteTo = pub
 	if err := n.ModifyAccountVotes(acc, ic.DAO, &acc.Balance, true); err != nil {
 		return err
 	}
 	ic.DAO.PutStorageItem(n.ID, key, acc.Bytes())
+
+	ic.AddNotification(n.Hash, "Vote", stackitem.NewArray([]stackitem.Item{
+		stackitem.NewByteArray(h.BytesBE()),
+		keyToStackItem(oldVote),
+		keyToStackItem(pub),
+		stackitem.NewBigInteger(&acc.Balance),
+	}))
+
 	if newGas != nil { // Can be if it was already distributed in the same block.
 		n.GAS.mint(ic, h, newGas, true)
 	}
 	return nil
 }
 
+func keyToStackItem(k *keys.PublicKey) stackitem.Item {
+	if k == nil {
+		return stackitem.Null{}
+	}
+	return stackitem.NewByteArray(k.Bytes())
+}
+
 // ModifyAccountVotes modifies votes of the specified account by value (can be negative).
 // typ specifies if this modify is occurring during transfer or vote (with old or new validator).
 func (n *NEO) ModifyAccountVotes(acc *state.NEOBalance, d *dao.Simple, value *big.Int, isNewVote bool) error {

pkg/core/native/native_test/neo_test.go

@@ -60,6 +60,61 @@ func TestNEO_RegisterPriceCache(t *testing.T) {
 	testGetSetCache(t, newNeoCommitteeClient(t, 100_0000_0000), "RegisterPrice", native.DefaultRegisterPrice)
 }
 
+func TestNEO_CandidateEvents(t *testing.T) {
+	c := newNativeClient(t, nativenames.Neo)
+	singleSigner := c.Signers[0].(neotest.MultiSigner).Single(0)
+	cc := c.WithSigners(c.Signers[0], singleSigner)
+	e := c.Executor
+	pkb := singleSigner.Account().PrivateKey().PublicKey().Bytes()
+
+	// Register 1 -> event
+	tx := cc.Invoke(t, true, "registerCandidate", pkb)
+	e.CheckTxNotificationEvent(t, tx, 0, state.NotificationEvent{
+		ScriptHash: c.Hash,
+		Name:       "CandidateStateChanged",
+		Item: stackitem.NewArray([]stackitem.Item{
+			stackitem.NewByteArray(pkb),
+			stackitem.NewBool(true),
+			stackitem.Make(0),
+		}),
+	})
+
+	// Register 2 -> no event
+	tx = cc.Invoke(t, true, "registerCandidate", pkb)
+	aer := e.GetTxExecResult(t, tx)
+	require.Equal(t, 0, len(aer.Events))
+
+	// Vote -> event
+	tx = c.Invoke(t, true, "vote", c.Signers[0].ScriptHash().BytesBE(), pkb)
+	e.CheckTxNotificationEvent(t, tx, 0, state.NotificationEvent{
+		ScriptHash: c.Hash,
+		Name:       "Vote",
+		Item: stackitem.NewArray([]stackitem.Item{
+			stackitem.NewByteArray(c.Signers[0].ScriptHash().BytesBE()),
+			stackitem.Null{},
+			stackitem.NewByteArray(pkb),
+			stackitem.Make(100000000),
+		}),
+	})
+
+	// Unregister 1 -> event
+	tx = cc.Invoke(t, true, "unregisterCandidate", pkb)
+	e.CheckTxNotificationEvent(t, tx, 0, state.NotificationEvent{
+		ScriptHash: c.Hash,
+		Name:       "CandidateStateChanged",
+		Item: stackitem.NewArray([]stackitem.Item{
+			stackitem.NewByteArray(pkb),
+			stackitem.NewBool(false),
+			stackitem.Make(100000000),
+		}),
+	})
+
+	// Unregister 2 -> no event
+	tx = cc.Invoke(t, true, "unregisterCandidate", pkb)
+	aer = e.GetTxExecResult(t, tx)
+	require.Equal(t, 0, len(aer.Events))
+}
+
 func TestNEO_Vote(t *testing.T) {
 	neoCommitteeInvoker := newNeoCommitteeClient(t, 100_0000_0000)
 	neoValidatorsInvoker := neoCommitteeInvoker.WithSigners(neoCommitteeInvoker.Validator)

pkg/rpc/server/server_test.go

@@ -75,7 +75,7 @@ const (
 	nfsoContractHash           = "5f9ebd6b001b54c7bc70f96e0412fcf415dfe09f"
 	nfsoToken1ID               = "7e244ffd6aa85fb1579d2ed22e9b761ab62e3486"
 	invokescriptContractAVM    = "VwIADBQBDAMOBQYMDQIODw0DDgcJAAAAAErZMCQE2zBwaEH4J+yMqiYEEUAMFA0PAwIJAAIBAwcDBAUCAQAOBgwJStkwJATbMHFpQfgn7IyqJgQSQBNA"
-	block20StateRootLE         = "0fbb19143cb782df2c893d448a89ec959bea8bf467faf747638975812d570f72"
+	block20StateRootLE         = "cda0adf452c190700f792bcac29973b85532b7c27192e96172cfa0c8acaa4f9e"
 )
 
 var (