Merge pull request #437 from harmony-one/fixNewbinary

Update Binary and Staking Calls based on new staking contract

node/node.go

@@ -15,6 +15,7 @@ import (
 	"github.com/harmony-one/harmony/drand"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/params"
@@ -31,6 +32,7 @@ import (
 	"github.com/harmony-one/harmony/api/service/explorer"
 	"github.com/harmony-one/harmony/api/service/networkinfo"
 	randomness_service "github.com/harmony-one/harmony/api/service/randomness"
+
 	"github.com/harmony-one/harmony/api/service/staking"
 	"github.com/harmony-one/harmony/api/service/syncing"
 	"github.com/harmony-one/harmony/api/service/syncing/downloader"
@@ -116,6 +118,17 @@ type syncConfig struct {
 	client    *downloader.Client
 }
 
+//constants related to staking
+//The first four bytes of the call data for a function call specifies the function to be called.
+//It is the first (left, high-order in big-endian) four bytes of the Keccak-256 (SHA-3)
+//Refer: https://solidity.readthedocs.io/en/develop/abi-spec.html
+
+const (
+	depositFuncSignature  = "0xd0e30db0"
+	withdrawFuncSignature = "0x2e1a7d4d"
+	funcSingatureBytes    = 4
+)
+
 // Node represents a protocol-participating node in the network
 type Node struct {
 	Consensus              *bft.Consensus       // Consensus object containing all Consensus related data (e.g. committee members, signatures, commits)
@@ -272,6 +285,7 @@ func New(host p2p.Host, consensus *bft.Consensus, db ethdb.Database) *Node {
 		node.blockchain = chain
 		node.BlockChannel = make(chan *types.Block)
 		node.ConfirmedBlockChannel = make(chan *types.Block)
+
 		node.TxPool = core.NewTxPool(core.DefaultTxPoolConfig, params.TestChainConfig, chain)
 		node.Worker = worker.New(params.TestChainConfig, chain, node.Consensus, pki.GetAddressFromPublicKey(node.SelfPeer.PubKey), node.Consensus.ShardID)
 		node.AddFaucetContractToPendingTransactions()
@@ -632,27 +646,27 @@ func (node *Node) UpdateStakingList(block *types.Block) error {
 	txns := block.Transactions()
 	for i := range txns {
 		txn := txns[i]
-		value := txn.Value().Int64()
-		currentSender, _ := types.Sender(signerType, txn)
-		_, isPresent := node.CurrentStakes[currentSender]
 		toAddress := txn.To()
 		if *toAddress != node.StakingContractAddress { //Not a address aimed at the staking contract.
 			continue
 		}
-		//This should be based on a switch case on function signature.
-		//TODO (ak) https://github.com/harmony-one/harmony/issues/430
-		if value > int64(0) { //If value >0 means its a staking deposit transaction
+		currentSender, _ := types.Sender(signerType, txn)
+		_, isPresent := node.CurrentStakes[currentSender]
+		data := txn.Data()
+		switch funcSignature := decodeFuncSign(data); funcSignature {
+		case depositFuncSignature: //deposit, currently: 0xd0e30db0
+			amount := txn.Value()
+			value := amount.Int64()
 			if isPresent {
-				//This means this node has increaserd its stake
+				//This means the node has increased its stake.
 				node.CurrentStakes[currentSender] += value
 			} else {
+				//This means its a new node that is staking the first time.
 				node.CurrentStakes[currentSender] = value
 			}
-		} else { //This means node has withdrawn stake.
-			getData := txn.Data()
-			value := decodeStakeCall(getData) //Value being withdrawn
+		case withdrawFuncSignature: //withdaw, currently: 0x2e1a7d4d
+			value := decodeStakeCall(data)
 			if isPresent {
-				//This means this node has increaserd its stake
 				if node.CurrentStakes[currentSender] > value {
 					node.CurrentStakes[currentSender] -= value
 				} else if node.CurrentStakes[currentSender] == value {
@@ -661,18 +675,33 @@ func (node *Node) UpdateStakingList(block *types.Block) error {
 					continue //Overdraft protection.
 				}
 			} else {
-				node.CurrentStakes[currentSender] = value
+				continue //no-op: a node that is not staked cannot withdraw stake.
 			}
+		default:
+			continue //no-op if its not deposit or withdaw
 		}
 	}
 	return nil
 }
 
+//The first four bytes of the call data for a function call specifies the function to be called.
+//It is the first (left, high-order in big-endian) four bytes of the Keccak-256 (SHA-3)
+//Refer: https://solidity.readthedocs.io/en/develop/abi-spec.html
 func decodeStakeCall(getData []byte) int64 {
 	value := new(big.Int)
-	value.SetBytes(getData[4:]) //Escape the method call.
+	value.SetBytes(getData[funcSingatureBytes:]) //Escape the method call.
 	return value.Int64()
 }
+
+//The first four bytes of the call data for a function call specifies the function to be called.
+//It is the first (left, high-order in big-endian) four bytes of the Keccak-256 (SHA-3)
+//Refer: https://solidity.readthedocs.io/en/develop/abi-spec.html
+//gets the function signature from data.
+func decodeFuncSign(data []byte) string {
+	funcSign := hexutil.Encode(data[:funcSingatureBytes]) //The function signature is first 4 bytes of data in ethereum
+	return funcSign
+}
+
 func (node *Node) setupForShardLeader() {
 	// Register explorer service.
 	node.serviceManager.RegisterService(service_manager.SupportExplorer, explorer.New(&node.SelfPeer))

node/node_test.go

@@ -243,17 +243,20 @@ func TestUpdateStakingWithdrawal(t *testing.T) {
 	node.StakingContractAddress = DepositContractAddress
 	node.AccountKey, _ = crypto.GenerateKey()
 	Address := crypto.PubkeyToAddress(node.AccountKey.PublicKey)
-	node.CurrentStakes[Address] = int64(1010)
+	initialStake := int64(1010)
+	node.CurrentStakes[Address] = initialStake //initial stake
 
-	withdrawFnSignature := []byte("withdraw(uint)")
+	withdrawFnSignature := []byte("withdraw(uint256)")
 	hash := sha3.NewLegacyKeccak256()
 	hash.Write(withdrawFnSignature)
 	methodID := hash.Sum(nil)[:4]
 
-	stake := "1000"
-	amount := new(big.Int)
-	amount.SetString(stake, 10)
-	paddedAmount := common.LeftPadBytes(amount.Bytes(), 32)
+	amount := "10"
+	stakeToWithdraw := new(big.Int)
+	stakeToWithdraw.SetString(amount, 10)
+	paddedAmount := common.LeftPadBytes(stakeToWithdraw.Bytes(), 32)
+
+	remainingStakeShouldBe := initialStake - stakeToWithdraw.Int64()
 
 	var dataEnc []byte
 	dataEnc = append(dataEnc, methodID...)
@@ -265,11 +268,11 @@ func TestUpdateStakingWithdrawal(t *testing.T) {
 	header := &types.Header{Extra: []byte("hello")}
 	block := types.NewBlock(header, txs, nil)
 	node.UpdateStakingList(block)
-	value, ok := node.CurrentStakes[Address]
+	currentStake, ok := node.CurrentStakes[Address]
 	if !ok {
 		t.Error("The correct address was not present")
 	}
-	if value != 10 {
+	if currentStake != remainingStakeShouldBe {
 		t.Error("The correct stake value was not subtracted")
 	}