core: vm: add totalSupply and totalStaked in the governance contract (#144)

Add totalSupply and totalStaked in the governance contract for the
preperation of DEXON cryptoeconomics 4.0.

Also removed the unstaked variable in node info and improve tests for
delegate/undeleate.

4 files changed, 144 insertions, 35 deletions

diff --git a/core/genesis.go b/core/genesis.go
index 38216361f..0948569f1 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -265,6 +265,7 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 	govStateHelper := vm.GovernanceStateHelper{StateDB: statedb}
 
+	totalSupply := big.NewInt(0)
 	totalStaked := big.NewInt(0)
 
 	for addr, account := range g.Alloc {
@@ -281,6 +282,8 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 		for key, value := range account.Storage {
 			statedb.SetState(addr, key, value)
 		}
+
+		totalSupply = new(big.Int).Add(totalSupply, account.Balance)
 	}
 
 	// For DEXON consensus genesis staking.
@@ -316,6 +319,9 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 
 		// Governance configuration.
 		govStateHelper.UpdateConfiguration(g.Config.Dexcon)
+
+		// Set totalSupply.
+		govStateHelper.IncTotalSupply(totalSupply)
 	}
 
 	root := statedb.IntermediateRoot(false)
diff --git a/core/vm/governance.go b/core/vm/governance.go
index b8228944a..bebc26e03 100644
--- a/core/vm/governance.go
+++ b/core/vm/governance.go
@@ -438,7 +438,7 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (ret []by
 		info := g.state.Node(index)
 		res, err := method.Outputs.Pack(
 			info.Owner, info.PublicKey, info.Staked, info.Fined,
-			info.Name, info.Email, info.Location, info.Url, info.Unstaked)
+			info.Name, info.Email, info.Location, info.Url)
 		if err != nil {
 			return nil, errExecutionReverted
 		}
@@ -497,13 +497,27 @@ func RunGovernanceContract(evm *EVM, input []byte, contract *Contract) (ret []by
 			return nil, errExecutionReverted
 		}
 		return res, nil
+	case "totalStaked":
+		res, err := method.Outputs.Pack(g.state.TotalStaked())
+		if err != nil {
+			return nil, errExecutionReverted
+		}
+		return res, nil
+	case "totalSupply":
+		res, err := method.Outputs.Pack(g.state.TotalSupply())
+		if err != nil {
+			return nil, errExecutionReverted
+		}
+		return res, nil
 	}
-	return nil, nil
+	return nil, errExecutionReverted
 }
 
 // Storage position enums.
 const (
 	roundHeightLoc = iota
+	totalSupplyLoc
+	totalStakedLoc
 	nodesLoc
 	nodesOffsetByAddressLoc
 	nodesOffsetByIDLoc
@@ -702,6 +716,28 @@ func (s *GovernanceStateHelper) PushRoundHeight(height *big.Int) {
 	s.setStateBigInt(loc, height)
 }
 
+// uint256 public totalSupply;
+func (s *GovernanceStateHelper) TotalSupply() *big.Int {
+	return s.getStateBigInt(big.NewInt(totalSupplyLoc))
+}
+func (s *GovernanceStateHelper) IncTotalSupply(amount *big.Int) {
+	s.setStateBigInt(big.NewInt(totalSupplyLoc), new(big.Int).Add(s.TotalSupply(), amount))
+}
+func (s *GovernanceStateHelper) DecTotalSupply(amount *big.Int) {
+	s.setStateBigInt(big.NewInt(totalSupplyLoc), new(big.Int).Sub(s.TotalSupply(), amount))
+}
+
+// uint256 public totalStaked;
+func (s *GovernanceStateHelper) TotalStaked() *big.Int {
+	return s.getStateBigInt(big.NewInt(totalStakedLoc))
+}
+func (s *GovernanceStateHelper) IncTotalStaked(amount *big.Int) {
+	s.setStateBigInt(big.NewInt(totalStakedLoc), new(big.Int).Add(s.TotalStaked(), amount))
+}
+func (s *GovernanceStateHelper) DecTotalStaked(amount *big.Int) {
+	s.setStateBigInt(big.NewInt(totalStakedLoc), new(big.Int).Sub(s.TotalStaked(), amount))
+}
+
 // struct Node {
 //     address owner;
 //     bytes publicKey;
@@ -711,7 +747,6 @@ func (s *GovernanceStateHelper) PushRoundHeight(height *big.Int) {
 //     string email;
 //     string location;
 //     string url;
-//     bool unstaked;
 // }
 //
 // Node[] nodes;
@@ -725,10 +760,9 @@ type nodeInfo struct {
 	Email     string
 	Location  string
 	Url       string
-	Unstaked  bool
 }
 
-const nodeStructSize = 9
+const nodeStructSize = 8
 
 func (s *GovernanceStateHelper) LenNodes() *big.Int {
 	return s.getStateBigInt(big.NewInt(nodesLoc))
@@ -772,10 +806,6 @@ func (s *GovernanceStateHelper) Node(index *big.Int) *nodeInfo {
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(7))
 	node.Url = string(s.readBytes(loc))
 
-	// Unstaked.
-	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(8))
-	node.Unstaked = s.getStateBigInt(loc).Cmp(big.NewInt(0)) > 0
-
 	return node
 }
 func (s *GovernanceStateHelper) PushNode(n *nodeInfo) {
@@ -787,7 +817,8 @@ func (s *GovernanceStateHelper) PushNode(n *nodeInfo) {
 }
 func (s *GovernanceStateHelper) UpdateNode(index *big.Int, n *nodeInfo) {
 	arrayBaseLoc := s.getSlotLoc(big.NewInt(nodesLoc))
-	elementBaseLoc := new(big.Int).Add(arrayBaseLoc, new(big.Int).Mul(index, big.NewInt(nodeStructSize)))
+	elementBaseLoc := new(big.Int).Add(arrayBaseLoc,
+		new(big.Int).Mul(index, big.NewInt(nodeStructSize)))
 
 	// Owner.
 	loc := elementBaseLoc
@@ -820,14 +851,6 @@ func (s *GovernanceStateHelper) UpdateNode(index *big.Int, n *nodeInfo) {
 	// Url.
 	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(7))
 	s.writeBytes(loc, []byte(n.Url))
-
-	// Unstaked.
-	loc = new(big.Int).Add(elementBaseLoc, big.NewInt(8))
-	val := big.NewInt(0)
-	if n.Unstaked {
-		val = big.NewInt(1)
-	}
-	s.setStateBigInt(loc, val)
 }
 func (s *GovernanceStateHelper) PopLastNode() {
 	// Decrease length by 1.
@@ -851,9 +874,6 @@ func (s *GovernanceStateHelper) QualifiedNodes() []*nodeInfo {
 	var nodes []*nodeInfo
 	for i := int64(0); i < int64(s.LenNodes().Uint64()); i++ {
 		node := s.Node(big.NewInt(i))
-		if node.Unstaked {
-			continue
-		}
 		if new(big.Int).Sub(node.Staked, node.Fined).Cmp(s.MinStake()) >= 0 {
 			nodes = append(nodes, node)
 		}
@@ -1265,6 +1285,9 @@ func (s *GovernanceStateHelper) Stake(
 		UndelegatedAt: big.NewInt(0),
 	})
 	s.PutDelegatorOffset(addr, addr, offset)
+
+	// Add to network total staked.
+	s.IncTotalStaked(staked)
 }
 
 const phiRatioMultiplier = 1000000.0
@@ -1725,6 +1748,9 @@ func (g *GovernanceContract) delegate(nodeAddr common.Address) ([]byte, error) {
 	node.Staked = new(big.Int).Add(node.Staked, g.contract.Value())
 	g.state.UpdateNode(offset, node)
 
+	// Add to network total staked.
+	g.state.IncTotalStaked(g.contract.Value())
+
 	// Push delegator record.
 	offset = g.state.LenDelegators(nodeAddr)
 	g.state.PushDelegator(nodeAddr, &delegatorInfo{
@@ -1810,6 +1836,10 @@ func (g *GovernanceContract) undelegateHelper(nodeAddr, caller common.Address) (
 
 	delegator := g.state.Delegator(nodeAddr, offset)
 
+	if delegator.UndelegatedAt.Cmp(big.NewInt(0)) != 0 {
+		return nil, errExecutionReverted
+	}
+
 	// Set undelegate time.
 	delegator.UndelegatedAt = g.evm.Time
 	g.state.UpdateDelegator(nodeAddr, offset, delegator)
@@ -1818,6 +1848,9 @@ func (g *GovernanceContract) undelegateHelper(nodeAddr, caller common.Address) (
 	node.Staked = new(big.Int).Sub(node.Staked, delegator.Value)
 	g.state.UpdateNode(nodeOffset, node)
 
+	// Subtract to network total staked.
+	g.state.DecTotalStaked(delegator.Value)
+
 	g.state.emitUndelegated(nodeAddr, caller)
 
 	return g.useGas(100000)
@@ -1914,10 +1947,6 @@ func (g *GovernanceContract) unstake() ([]byte, error) {
 		i = i.Sub(i, big.NewInt(1))
 	}
 
-	// Mark node as unstaked.
-	node.Unstaked = true
-	g.state.UpdateNode(offset, node)
-
 	g.state.emitUnstaked(caller)
 
 	return g.useGas(100000)
diff --git a/core/vm/governance_abi.go b/core/vm/governance_abi.go
index 74ccad0b7..1b700ac32 100644
--- a/core/vm/governance_abi.go
+++ b/core/vm/governance_abi.go
@@ -112,6 +112,20 @@ const GovernanceABIJSON = `
   },
   {
     "constant": true,
+    "inputs": [],
+    "name": "totalSupply",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
     "inputs": [
       {
         "name": "",
@@ -151,10 +165,6 @@ const GovernanceABIJSON = `
       {
         "name": "url",
         "type": "string"
-      },
-      {
-        "name": "unstaked",
-        "type": "bool"
       }
     ],
     "payable": false,
@@ -331,6 +341,20 @@ const GovernanceABIJSON = `
   {
     "constant": true,
     "inputs": [],
+    "name": "totalStaked",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint256"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
+  {
+    "constant": true,
+    "inputs": [],
     "name": "roundInterval",
     "outputs": [
       {
diff --git a/core/vm/governance_test.go b/core/vm/governance_test.go
index 4c5236565..8566d6537 100644
--- a/core/vm/governance_test.go
+++ b/core/vm/governance_test.go
@@ -205,6 +205,7 @@ func (g *GovernanceContractTestSuite) TestStakeUnstakeWithoutExtraDelegators() {
 	g.Require().Equal(1, int(g.s.LenNodes().Uint64()))
 	g.Require().Equal(1, len(g.s.QualifiedNodes()))
 	g.Require().Equal("Test1", g.s.Node(big.NewInt(0)).Name)
+	g.Require().Equal(amount.String(), g.s.TotalStaked().String())
 
 	// Check balance.
 	g.Require().Equal(new(big.Int).Sub(balanceBeforeStake, amount), g.stateDB.GetBalance(addr))
@@ -219,9 +220,14 @@ func (g *GovernanceContractTestSuite) TestStakeUnstakeWithoutExtraDelegators() {
 	g.Require().NoError(err)
 	_, err = g.call(addr, input, big.NewInt(0))
 	g.Require().NoError(err)
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
 	g.Require().Equal(1, int(g.s.LenDelegators(addr).Uint64()))
 	g.Require().Equal(1, int(g.s.LenNodes().Uint64()))
 
+	node := g.s.Node(big.NewInt(0))
+	g.Require().Equal(big.NewInt(0).String(), node.Staked.String())
+	g.Require().Equal(big.NewInt(0).String(), g.s.TotalStaked().String())
+
 	// Wait for lockup time than withdraw.
 	time.Sleep(time.Second * 2)
 	input, err = abiObject.Pack("withdraw", addr)
@@ -229,6 +235,7 @@ func (g *GovernanceContractTestSuite) TestStakeUnstakeWithoutExtraDelegators() {
 	_, err = g.call(addr, input, big.NewInt(0))
 	g.Require().NoError(err)
 
+	g.Require().Equal(0, len(g.s.QualifiedNodes()))
 	g.Require().Equal(0, int(g.s.LenDelegators(addr).Uint64()))
 	g.Require().Equal(0, int(g.s.LenNodes().Uint64()))
 
@@ -251,16 +258,18 @@ func (g *GovernanceContractTestSuite) TestStakeUnstakeWithoutExtraDelegators() {
 	g.Require().NoError(err)
 
 	g.Require().Equal(2, len(g.s.QualifiedNodes()))
+	g.Require().Equal(new(big.Int).Mul(amount, big.NewInt(2)).String(), g.s.TotalStaked().String())
 
 	// 2nd node Unstake.
 	input, err = abiObject.Pack("unstake")
 	g.Require().NoError(err)
 	_, err = g.call(addr2, input, big.NewInt(0))
 	g.Require().NoError(err)
-	node := g.s.Node(big.NewInt(0))
+	node = g.s.Node(big.NewInt(0))
 	g.Require().Equal("Test2", node.Name)
-	g.Require().Equal(true, node.Unstaked)
+	g.Require().Equal(big.NewInt(0).String(), node.Staked.String())
 	g.Require().Equal(1, len(g.s.QualifiedNodes()))
+	g.Require().Equal(amount.String(), g.s.TotalStaked().String())
 
 	time.Sleep(time.Second * 2)
 	input, err = abiObject.Pack("withdraw", addr2)
@@ -279,6 +288,8 @@ func (g *GovernanceContractTestSuite) TestStakeUnstakeWithoutExtraDelegators() {
 	_, err = g.call(addr, input, big.NewInt(0))
 	g.Require().NoError(err)
 	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+	g.Require().Equal(big.NewInt(0).String(), g.s.TotalStaked().String())
+
 	time.Sleep(time.Second * 2)
 	input, err = abiObject.Pack("withdraw", addr)
 	g.Require().NoError(err)
@@ -322,6 +333,7 @@ func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
 	g.Require().Equal(new(big.Int).Sub(balanceBeforeDelegate, amount), g.stateDB.GetBalance(addrDelegator))
 	g.Require().Equal(addrDelegator, g.s.Delegator(addr, big.NewInt(1)).Owner)
 	g.Require().Equal(new(big.Int).Add(amount, ownerStaked), g.s.Node(big.NewInt(0)).Staked)
+	g.Require().Equal(g.s.Node(big.NewInt(0)).Staked.String(), g.s.TotalStaked().String())
 	g.Require().Equal(1, int(g.s.DelegatorsOffset(addr, addrDelegator).Int64()))
 
 	// Same person delegate the 2nd time should fail.
@@ -339,6 +351,7 @@ func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
 	g.Require().Equal(addrDelegator2, g.s.Delegator(addr, big.NewInt(2)).Owner)
 	g.Require().Equal(new(big.Int).Add(ownerStaked, new(big.Int).Mul(amount, big.NewInt(2))),
 		g.s.Node(big.NewInt(0)).Staked)
+	g.Require().Equal(g.s.Node(big.NewInt(0)).Staked.String(), g.s.TotalStaked().String())
 	g.Require().Equal(2, int(g.s.DelegatorsOffset(addr, addrDelegator2).Int64()))
 
 	// Qualified.
@@ -349,8 +362,14 @@ func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
 	input, err = abiObject.Pack("undelegate", addr)
 	g.Require().NoError(err)
 	_, err = g.call(addrDelegator, input, big.NewInt(0))
+	g.Require().Equal(new(big.Int).Add(amount, ownerStaked), g.s.Node(big.NewInt(0)).Staked)
+	g.Require().Equal(g.s.Node(big.NewInt(0)).Staked.String(), g.s.TotalStaked().String())
 	g.Require().NoError(err)
 
+	// Undelegate the second time should fail.
+	_, err = g.call(addrDelegator, input, big.NewInt(0))
+	g.Require().Error(err)
+
 	// Withdraw within lockup time should fail.
 	input, err = abiObject.Pack("withdraw", addr)
 	g.Require().NoError(err)
@@ -377,7 +396,7 @@ func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
 	input, err = abiObject.Pack("withdraw", addr)
 	g.Require().NoError(err)
 	_, err = g.call(addrDelegator, input, big.NewInt(0))
-	g.Require().NotNil(err)
+	g.Require().Error(err)
 
 	// Undelegate addrDelegator2.
 	balanceBeforeUnDelegate = g.stateDB.GetBalance(addrDelegator2)
@@ -386,6 +405,9 @@ func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
 	_, err = g.call(addrDelegator2, input, big.NewInt(0))
 	g.Require().NoError(err)
 
+	g.Require().Equal(ownerStaked, g.s.Node(big.NewInt(0)).Staked)
+	g.Require().Equal(g.s.Node(big.NewInt(0)).Staked.String(), g.s.TotalStaked().String())
+
 	// Wait for lockup time than withdraw.
 	time.Sleep(time.Second * 2)
 	input, err = abiObject.Pack("withdraw", addr)
@@ -399,6 +421,25 @@ func (g *GovernanceContractTestSuite) TestDelegateUndelegate() {
 
 	// Unqualified
 	g.Require().Equal(0, len(g.s.QualifiedNodes()))
+
+	// Owner undelegate itself.
+	g.Require().Equal(1, int(g.s.LenNodes().Uint64()))
+	g.Require().Equal(1, int(g.s.LenDelegators(addr).Uint64()))
+
+	input, err = abiObject.Pack("undelegate", addr)
+	g.Require().NoError(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NoError(err)
+	g.Require().Equal(big.NewInt(0).String(), g.s.Node(big.NewInt(0)).Staked.String())
+	g.Require().Equal(big.NewInt(0).String(), g.s.TotalStaked().String())
+
+	time.Sleep(time.Second * 2)
+	input, err = abiObject.Pack("withdraw", addr)
+	g.Require().NoError(err)
+	_, err = g.call(addr, input, big.NewInt(0))
+
+	g.Require().Equal(0, int(g.s.LenNodes().Uint64()))
+	g.Require().Equal(0, int(g.s.LenDelegators(addr).Uint64()))
 }
 
 func (g *GovernanceContractTestSuite) TestFine() {
@@ -485,7 +526,6 @@ func (g *GovernanceContractTestSuite) TestFine() {
 	g.Require().NoError(err)
 	_, err = g.call(addrDelegator, input, big.NewInt(0))
 	g.Require().NoError(err)
-
 }
 
 func (g *GovernanceContractTestSuite) TestUnstakeWithExtraDelegators() {
@@ -893,9 +933,19 @@ func (g *GovernanceContractTestSuite) TestMiscVariableReading() {
 	privKey, addr := g.newPrefundAccount()
 	pk := crypto.FromECDSAPub(&privKey.PublicKey)
 
+	input, err := abiObject.Pack("totalSupply")
+	g.Require().NoError(err)
+	res, err := g.call(addr, input, big.NewInt(0))
+	g.Require().NoError(err)
+
+	input, err = abiObject.Pack("totalStaked")
+	g.Require().NoError(err)
+	res, err = g.call(addr, input, big.NewInt(0))
+	g.Require().NoError(err)
+
 	// Stake.
 	amount := new(big.Int).Mul(big.NewInt(1e18), big.NewInt(5e4))
-	input, err := abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
+	input, err = abiObject.Pack("stake", pk, "Test1", "test1@dexon.org", "Taipei, Taiwan", "https://dexon.org")
 	g.Require().NoError(err)
 	_, err = g.call(addr, input, amount)
 	g.Require().NoError(err)
@@ -917,7 +967,7 @@ func (g *GovernanceContractTestSuite) TestMiscVariableReading() {
 
 	input, err = abiObject.Pack("nodes", big.NewInt(0))
 	g.Require().NoError(err)
-	res, err := g.call(addr, input, big.NewInt(0))
+	res, err = g.call(addr, input, big.NewInt(0))
 	g.Require().NoError(err)
 
 	input, err = abiObject.Pack("nodesLength")