Abstract transactions in tx pool and add staking transaction to pool with error report (#2236)

* [core] Add tx-pool txn interface & update supporting components

* Add txn interface (`PoolTransaction`) for tx-pool
* Update tx_journal to handle pool's txn interface
* Update tx_list to handle pool's txn interface

* [staking] Satisfy `PoolTransaction` interface & move error sink types

* Implement `Protected`, `ToShardID`, `To`, `Data`, `Value` and `Size`
for `StakingTransaction` to satisfy `PoolTransaction` interface
* Refactor `Price` to `GasPrice` for `StakingTransaction` to
satisfy `PoolTransaction` interface
* Move error sink related components to transaction.go
* Expose `VerifyBLSKey` and `VerifyBLSKeys`

* [core] Generalize tx pool & refactor error sink logic

* Refactor txn logic to use `PoolTransaction` and `PoolTransactions`
* Add `txPoolErrorReporter` to handle reporting to plainTx and stakingTx
error sinks
* Remove old & unpayable txs error reports (to error sink) since errs
are already reported when adding the txs
* Fix known transaction error report when adding txn batches
* Add error sink reporting when failed to enqueue txs

* [node] Fix error sink & update tx pool interaction

* Integrate staking transaction in tx-pool
* Remove staking transaction error sink

* [hmy api] Integrate staking transactions from tx pool

* Remove looking at tx pool for `GetTransactionByHash`
* Add `PendingStakingTransactions` and update `PendingTransactions` to
only return plainTx

* [tests] Update all tests for tx pool txn interface & staking err sink

* Update transactions to `PoolTransaction` interface
* Remove `CommitTransactions` staking txn error sink
* Add basic staking txn tests to tx pool tests

* [node] Make all node broadcast staking tx and plain tx

* [core + staking] Separate staking msg check and put in tx pool

* Move `Validator` specific sanity check into its own method and
call said method in `ValidatorWrapper` sanity check
* Create staking msg verifiers and preprocessors in `staking_verifier.go`
* Remove staking msg verification on all staking msg applications
in `state_transition.go` and call new staking msg verifiers & preprocessors
* Add staking msg verification to tx pool
* Remove `ToShardID` from `PoolTransaction` interface and remove trivial
implementation of `ToShardID` in `StakingTransaction`

core/staking_verifier.go

@@ -0,0 +1,266 @@
+package core
+
+import (
+	"bytes"
+	"math/big"
+
+	"github.com/pkg/errors"
+
+	"github.com/harmony-one/harmony/core/vm"
+	common2 "github.com/harmony-one/harmony/internal/common"
+	staking "github.com/harmony-one/harmony/staking/types"
+)
+
+var (
+	errStateDBIsMissing    = errors.New("no stateDB was provided")
+	errChainContextMissing = errors.New("no chain context was provided")
+	errEpochMissing        = errors.New("no epoch was provided")
+	errBlockNumMissing     = errors.New("no block number was provided")
+)
+
+// TODO: add unit tests to check staking msg verification
+
+// VerifyAndCreateValidatorFromMsg verifies the create validator message using
+// the stateDB, epoch, & blocknumber and returns the validatorWrapper created
+// in the process.
+//
+// Note that this function never updates the stateDB, it only reads from stateDB.
+func VerifyAndCreateValidatorFromMsg(
+	stateDB vm.StateDB, epoch *big.Int, blockNum *big.Int, msg *staking.CreateValidator,
+) (*staking.ValidatorWrapper, error) {
+	if stateDB == nil {
+		return nil, errStateDBIsMissing
+	}
+	if epoch == nil {
+		return nil, errEpochMissing
+	}
+	if blockNum == nil {
+		return nil, errBlockNumMissing
+	}
+	if msg.Amount.Sign() == -1 {
+		return nil, errNegativeAmount
+	}
+	if stateDB.IsValidator(msg.ValidatorAddress) {
+		return nil, errors.Wrapf(errValidatorExist, common2.MustAddressToBech32(msg.ValidatorAddress))
+	}
+	if !CanTransfer(stateDB, msg.ValidatorAddress, msg.Amount) {
+		return nil, errInsufficientBalanceForStake
+	}
+	v, err := staking.CreateValidatorFromNewMsg(msg, blockNum)
+	if err != nil {
+		return nil, err
+	}
+	wrapper := &staking.ValidatorWrapper{}
+	wrapper.Validator = *v
+	wrapper.Delegations = []staking.Delegation{
+		staking.NewDelegation(v.Address, msg.Amount),
+	}
+	wrapper.Snapshot.Epoch = epoch
+	wrapper.Snapshot.NumBlocksSigned = big.NewInt(0)
+	wrapper.Snapshot.NumBlocksToSign = big.NewInt(0)
+	if err := wrapper.SanityCheck(); err != nil {
+		return nil, err
+	}
+	return wrapper, nil
+}
+
+// VerifyAndEditValidatorFromMsg verifies the edit validator message using
+// the stateDB, chainContext and returns the edited validatorWrapper.
+//
+// Note that this function never updates the stateDB, it only reads from stateDB.
+func VerifyAndEditValidatorFromMsg(
+	stateDB vm.StateDB, chainContext ChainContext, blockNum *big.Int, msg *staking.EditValidator,
+) (*staking.ValidatorWrapper, error) {
+	if stateDB == nil {
+		return nil, errStateDBIsMissing
+	}
+	if chainContext == nil {
+		return nil, errChainContextMissing
+	}
+	if blockNum == nil {
+		return nil, errBlockNumMissing
+	}
+	if !stateDB.IsValidator(msg.ValidatorAddress) {
+		return nil, errValidatorNotExist
+	}
+	wrapper := stateDB.GetStakingInfo(msg.ValidatorAddress)
+	if wrapper == nil {
+		return nil, errValidatorNotExist
+	}
+	if err := staking.UpdateValidatorFromEditMsg(&wrapper.Validator, msg); err != nil {
+		return nil, err
+	}
+	newRate := wrapper.Validator.Rate
+	if newRate.GT(wrapper.Validator.MaxRate) {
+		return nil, errCommissionRateChangeTooHigh
+	}
+
+	// TODO: make sure we are reading from the correct snapshot
+	snapshotValidator, err := chainContext.ReadValidatorSnapshot(wrapper.Address)
+	if err != nil {
+		return nil, err
+	}
+	rateAtBeginningOfEpoch := snapshotValidator.Validator.Rate
+
+	if rateAtBeginningOfEpoch.IsNil() || (!newRate.IsNil() && !rateAtBeginningOfEpoch.Equal(newRate)) {
+		wrapper.Validator.UpdateHeight = blockNum
+	}
+
+	if newRate.Sub(rateAtBeginningOfEpoch).Abs().GT(wrapper.Validator.MaxChangeRate) {
+		return nil, errCommissionRateChangeTooFast
+	}
+
+	if err := wrapper.SanityCheck(); err != nil {
+		return nil, err
+	}
+	return wrapper, nil
+}
+
+// VerifyAndDelegateFromMsg verifies the delegate message using the stateDB
+// and returns the balance to be deducted by the delegator as well as the
+// validatorWrapper with the delegation applied to it.
+//
+// Note that this function never updates the stateDB, it only reads from stateDB.
+func VerifyAndDelegateFromMsg(
+	stateDB vm.StateDB, msg *staking.Delegate,
+) (*staking.ValidatorWrapper, *big.Int, error) {
+	if stateDB == nil {
+		return nil, nil, errStateDBIsMissing
+	}
+	if msg.Amount.Sign() == -1 {
+		return nil, nil, errNegativeAmount
+	}
+	if !stateDB.IsValidator(msg.ValidatorAddress) {
+		return nil, nil, errValidatorNotExist
+	}
+	wrapper := stateDB.GetStakingInfo(msg.ValidatorAddress)
+	if wrapper == nil {
+		return nil, nil, errValidatorNotExist
+	}
+	// Check for redelegation
+	for i := range wrapper.Delegations {
+		delegation := &wrapper.Delegations[i]
+		if bytes.Equal(delegation.DelegatorAddress.Bytes(), msg.DelegatorAddress.Bytes()) {
+			totalInUndelegation := delegation.TotalInUndelegation()
+			balance := stateDB.GetBalance(msg.DelegatorAddress)
+			// If the sum of normal balance and the total amount of tokens in undelegation is greater than the amount to delegate
+			if big.NewInt(0).Add(totalInUndelegation, balance).Cmp(msg.Amount) >= 0 {
+				// Check if it can use tokens in undelegation to delegate (redelegate)
+				delegateBalance := big.NewInt(0).Set(msg.Amount)
+				// Use the latest undelegated token first as it has the longest remaining locking time.
+				i := len(delegation.Undelegations) - 1
+				for ; i >= 0; i-- {
+					if delegation.Undelegations[i].Amount.Cmp(delegateBalance) <= 0 {
+						delegateBalance.Sub(delegateBalance, delegation.Undelegations[i].Amount)
+					} else {
+						delegation.Undelegations[i].Amount.Sub(delegation.Undelegations[i].Amount, delegateBalance)
+						delegateBalance = big.NewInt(0)
+						break
+					}
+				}
+				delegation.Undelegations = delegation.Undelegations[:i+1]
+				delegation.Amount.Add(delegation.Amount, msg.Amount)
+				if err := wrapper.SanityCheck(); err != nil {
+					return nil, nil, err
+				}
+				// Return remaining balance to be deducted for delegation
+				if delegateBalance.Cmp(big.NewInt(0)) < 0 {
+					return nil, nil, errInsufficientBalanceForStake // shouldn't really happen
+				}
+				return wrapper, delegateBalance, nil
+			}
+			return nil, nil, errors.Wrapf(
+				errInsufficientBalanceForStake,
+				"total-delegated %s own-current-balance %s amount-to-delegate %s",
+				totalInUndelegation.String(),
+				balance.String(),
+				msg.Amount.String(),
+			)
+		}
+	}
+	// If no redelegation, create new delegation
+	if !CanTransfer(stateDB, msg.DelegatorAddress, msg.Amount) {
+		return nil, nil, errInsufficientBalanceForStake
+	}
+	wrapper.Delegations = append(wrapper.Delegations, staking.NewDelegation(msg.DelegatorAddress, msg.Amount))
+	if err := wrapper.SanityCheck(); err != nil {
+		return nil, nil, err
+	}
+	return wrapper, msg.Amount, nil
+}
+
+// VerifyAndUndelegateFromMsg verifies the undelegate validator message
+// using the stateDB & chainContext and returns the edited validatorWrapper
+// with the undelegation applied to it.
+//
+// Note that this function never updates the stateDB, it only reads from stateDB.
+func VerifyAndUndelegateFromMsg(
+	stateDB vm.StateDB, epoch *big.Int, msg *staking.Undelegate,
+) (*staking.ValidatorWrapper, error) {
+	if stateDB == nil {
+		return nil, errStateDBIsMissing
+	}
+	if epoch == nil {
+		return nil, errEpochMissing
+	}
+	if msg.Amount.Sign() == -1 {
+		return nil, errNegativeAmount
+	}
+	if !stateDB.IsValidator(msg.ValidatorAddress) {
+		return nil, errValidatorNotExist
+	}
+	wrapper := stateDB.GetStakingInfo(msg.ValidatorAddress)
+	if wrapper == nil {
+		return nil, errValidatorNotExist
+	}
+	for i := range wrapper.Delegations {
+		delegation := &wrapper.Delegations[i]
+		if bytes.Equal(delegation.DelegatorAddress.Bytes(), msg.DelegatorAddress.Bytes()) {
+			if err := delegation.Undelegate(epoch, msg.Amount); err != nil {
+				return nil, err
+			}
+			if err := wrapper.SanityCheck(); err != nil {
+				return nil, err
+			}
+			return wrapper, nil
+		}
+	}
+	return nil, errNoDelegationToUndelegate
+}
+
+// VerifyAndCollectRewardsFromDelegation verifies and collects rewards
+// from the given delegation slice using the stateDB. It returns all of the
+// edited validatorWrappers and the sum total of the rewards.
+//
+// Note that this function never updates the stateDB, it only reads from stateDB.
+func VerifyAndCollectRewardsFromDelegation(
+	stateDB vm.StateDB, delegations []staking.DelegationIndex,
+) ([]*staking.ValidatorWrapper, *big.Int, error) {
+	if stateDB == nil {
+		return nil, nil, errStateDBIsMissing
+	}
+	updatedValidatorWrappers := []*staking.ValidatorWrapper{}
+	totalRewards := big.NewInt(0)
+	for i := range delegations {
+		delegation := &delegations[i]
+		wrapper := stateDB.GetStakingInfo(delegation.ValidatorAddress)
+		if wrapper == nil {
+			return nil, nil, errValidatorNotExist
+		}
+		if uint64(len(wrapper.Delegations)) > delegation.Index {
+			delegation := &wrapper.Delegations[delegation.Index]
+			if delegation.Reward.Cmp(big.NewInt(0)) > 0 {
+				totalRewards.Add(totalRewards, delegation.Reward)
+			}
+			delegation.Reward.SetUint64(0)
+		}
+		if err := wrapper.SanityCheck(); err != nil {
+			return nil, nil, err
+		}
+		updatedValidatorWrappers = append(updatedValidatorWrappers, wrapper)
+	}
+	if totalRewards.Int64() == 0 {
+		return nil, nil, errNoRewardsToCollect
+	}
+	return updatedValidatorWrappers, totalRewards, nil
+}

core/state_processor.go

@@ -282,7 +282,7 @@ func StakingToMessage(tx *staking.StakingTransaction, blockNum *big.Int) (types.
 		return types.Message{}, err
 	}
 
-	msg := types.NewStakingMessage(from, tx.Nonce(), tx.Gas(), tx.Price(), payload, blockNum)
+	msg := types.NewStakingMessage(from, tx.Nonce(), tx.Gas(), tx.GasPrice(), payload, blockNum)
 	stkType := tx.StakingType()
 	if _, ok := types.StakingTypeMap[stkType]; !ok {
 		return types.Message{}, staking.ErrInvalidStakingKind

core/state_transition.go

@@ -17,7 +17,6 @@
 package core
 
 import (
-	"bytes"
 	"math"
 	"math/big"
 
@@ -25,7 +24,6 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/harmony-one/harmony/core/types"
 	"github.com/harmony-one/harmony/core/vm"
-	common2 "github.com/harmony-one/harmony/internal/common"
 	"github.com/harmony-one/harmony/internal/params"
 	"github.com/harmony-one/harmony/internal/utils"
 	staking "github.com/harmony-one/harmony/staking/types"
@@ -295,8 +293,6 @@ func (st *StateTransition) StakingTransitionDb() (usedGas uint64, err error) {
 	// Pay intrinsic gas
 	// TODO: propose staking-specific formula for staking transaction
 	gas, err := IntrinsicGas(st.data, false, homestead, msg.Type() == types.StakeCreateVal)
-	// TODO Remove this logging
-	utils.Logger().Info().Uint64("Using", gas).Msg("Gas cost of staking transaction being processed")
 
 	if err != nil {
 		return 0, err
@@ -314,54 +310,51 @@ func (st *StateTransition) StakingTransitionDb() (usedGas uint64, err error) {
 		if err = rlp.DecodeBytes(msg.Data(), stkMsg); err != nil {
 			return 0, err
 		}
-		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, txn: %+v", msg.Type(), stkMsg)
+		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, gas: %d, txn: %+v", msg.Type(), gas, stkMsg)
 		if msg.From() != stkMsg.ValidatorAddress {
 			return 0, errInvalidSigner
 		}
-		err = st.applyCreateValidatorTx(stkMsg, msg.BlockNum())
+		err = st.verifyAndApplyCreateValidatorTx(stkMsg, msg.BlockNum())
-
 	case types.StakeEditVal:
 		stkMsg := &staking.EditValidator{}
 		if err = rlp.DecodeBytes(msg.Data(), stkMsg); err != nil {
 			return 0, err
 		}
-		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, txn: %+v", msg.Type(), stkMsg)
+		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, gas: %d, txn: %+v", msg.Type(), gas, stkMsg)
 		if msg.From() != stkMsg.ValidatorAddress {
 			return 0, errInvalidSigner
 		}
-		err = st.applyEditValidatorTx(stkMsg, msg.BlockNum())
+		err = st.verifyAndApplyEditValidatorTx(stkMsg, msg.BlockNum())
-
 	case types.Delegate:
 		stkMsg := &staking.Delegate{}
 		if err = rlp.DecodeBytes(msg.Data(), stkMsg); err != nil {
 			return 0, err
 		}
-		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, txn: %+v", msg.Type(), stkMsg)
+		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, gas: %d, txn: %+v", msg.Type(), gas, stkMsg)
 		if msg.From() != stkMsg.DelegatorAddress {
 			return 0, errInvalidSigner
 		}
-		err = st.applyDelegateTx(stkMsg)
+		err = st.verifyAndApplyDelegateTx(stkMsg)
-
 	case types.Undelegate:
 		stkMsg := &staking.Undelegate{}
 		if err = rlp.DecodeBytes(msg.Data(), stkMsg); err != nil {
 			return 0, err
 		}
-		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, txn: %+v", msg.Type(), stkMsg)
+		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, gas: %d, txn: %+v", msg.Type(), gas, stkMsg)
 		if msg.From() != stkMsg.DelegatorAddress {
 			return 0, errInvalidSigner
 		}
-		err = st.applyUndelegateTx(stkMsg)
+		err = st.verifyAndApplyUndelegateTx(stkMsg)
 	case types.CollectRewards:
 		stkMsg := &staking.CollectRewards{}
 		if err = rlp.DecodeBytes(msg.Data(), stkMsg); err != nil {
 			return 0, err
 		}
-		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, txn: %+v", msg.Type(), stkMsg)
+		utils.Logger().Info().Msgf("[DEBUG STAKING] staking type: %s, gas: %d, txn: %+v", msg.Type(), gas, stkMsg)
 		if msg.From() != stkMsg.DelegatorAddress {
 			return 0, errInvalidSigner
 		}
-		err = st.applyCollectRewards(stkMsg)
+		err = st.verifyAndApplyCollectRewards(stkMsg)
 	default:
 		return 0, staking.ErrInvalidStakingKind
 	}
@@ -373,231 +366,67 @@ func (st *StateTransition) StakingTransitionDb() (usedGas uint64, err error) {
 	return st.gasUsed(), err
 }
 
-func (st *StateTransition) applyCreateValidatorTx(createValidator *staking.CreateValidator, blockNum *big.Int) error {
+func (st *StateTransition) verifyAndApplyCreateValidatorTx(
-	if createValidator.Amount.Sign() == -1 {
+	createValidator *staking.CreateValidator, blockNum *big.Int,
-		return errNegativeAmount
+) error {
-	}
+	wrapper, err := VerifyAndCreateValidatorFromMsg(st.state, st.evm.EpochNumber, blockNum, createValidator)
-
-	if val := createValidator.ValidatorAddress; st.state.IsValidator(val) {
-		return errors.Wrapf(errValidatorExist, common2.MustAddressToBech32(val))
-	}
-
-	if !CanTransfer(st.state, createValidator.ValidatorAddress, createValidator.Amount) {
-		return errInsufficientBalanceForStake
-	}
-
-	v, err := staking.CreateValidatorFromNewMsg(createValidator, blockNum)
 	if err != nil {
 		return err
 	}
-
+	if err := st.state.UpdateStakingInfo(wrapper.Validator.Address, wrapper); err != nil {
-	zero := big.NewInt(0)
-	wrapper := staking.ValidatorWrapper{}
-	wrapper.Validator = *v
-	wrapper.Delegations = []staking.Delegation{
-		staking.NewDelegation(v.Address, createValidator.Amount),
-	}
-	wrapper.Snapshot.Epoch = st.evm.EpochNumber
-	wrapper.Snapshot.NumBlocksSigned = zero
-	wrapper.Snapshot.NumBlocksToSign = zero
-
-	if err := st.state.UpdateStakingInfo(v.Address, &wrapper); err != nil {
 		return err
 	}
-
+	st.state.SetValidatorFlag(wrapper.Validator.Address)
-	st.state.SetValidatorFlag(v.Address)
+	st.state.SubBalance(wrapper.Address, createValidator.Amount)
-	st.state.SubBalance(v.Address, createValidator.Amount)
 	return nil
 }
 
-func (st *StateTransition) applyEditValidatorTx(
+func (st *StateTransition) verifyAndApplyEditValidatorTx(
 	editValidator *staking.EditValidator, blockNum *big.Int,
 ) error {
-	if !st.state.IsValidator(editValidator.ValidatorAddress) {
+	wrapper, err := VerifyAndEditValidatorFromMsg(st.state, st.bc, blockNum, editValidator)
-		return errValidatorNotExist
-	}
-
-	wrapper := st.state.GetStakingInfo(editValidator.ValidatorAddress)
-	if wrapper == nil {
-		return errValidatorNotExist
-	}
-
-	if err := staking.UpdateValidatorFromEditMsg(&wrapper.Validator, editValidator); err != nil {
-		return err
-	}
-	newRate := wrapper.Validator.Rate
-
-	// TODO: make sure we are reading from the correct snapshot
-	snapshotValidator, err := st.bc.ReadValidatorSnapshot(wrapper.Address)
 	if err != nil {
 		return err
 	}
-	rateAtBeginningOfEpoch := snapshotValidator.Validator.Rate
+	return st.state.UpdateStakingInfo(wrapper.Address, wrapper)
-
-	if rateAtBeginningOfEpoch.IsNil() || (!newRate.IsNil() && !rateAtBeginningOfEpoch.Equal(newRate)) {
-		wrapper.Validator.UpdateHeight = blockNum
-	}
-
-	if newRate.Sub(rateAtBeginningOfEpoch).Abs().GT(wrapper.Validator.MaxChangeRate) {
-		return errCommissionRateChangeTooFast
-	}
-
-	if newRate.GT(wrapper.Validator.MaxRate) {
-		return errCommissionRateChangeTooHigh
-	}
-
-	if err := st.state.UpdateStakingInfo(wrapper.Address, wrapper); err != nil {
-		return err
-	}
-	return nil
 }
 
-func (st *StateTransition) applyDelegateTx(delegate *staking.Delegate) error {
+func (st *StateTransition) verifyAndApplyDelegateTx(delegate *staking.Delegate) error {
-	if delegate.Amount.Sign() == -1 {
+	wrapper, balanceToBeDeducted, err := VerifyAndDelegateFromMsg(st.state, delegate)
-		return errNegativeAmount
-	}
-
-	if !st.state.IsValidator(delegate.ValidatorAddress) {
-		return errValidatorNotExist
-	}
-	wrapper := st.state.GetStakingInfo(delegate.ValidatorAddress)
-	if wrapper == nil {
-		return errValidatorNotExist
-	}
-
-	stateDB := st.state
-	delegatorExist := false
-	for i := range wrapper.Delegations {
-		delegation := &wrapper.Delegations[i]
-		if bytes.Equal(delegation.DelegatorAddress.Bytes(), delegate.DelegatorAddress.Bytes()) {
-			delegatorExist = true
-			totalInUndelegation := delegation.TotalInUndelegation()
-			balance := stateDB.GetBalance(delegate.DelegatorAddress)
-			// If the sum of normal balance and the total amount of tokens in undelegation is greater than the amount to delegate
-			if big.NewInt(0).Add(totalInUndelegation, balance).Cmp(delegate.Amount) >= 0 {
-				// Firstly use the tokens in undelegation to delegate (redelegate)
-				delegateBalance := big.NewInt(0).Set(delegate.Amount)
-				// Use the latest undelegated token first as it has the longest remaining locking time.
-				i := len(delegation.Undelegations) - 1
-				for ; i >= 0; i-- {
-					if delegation.Undelegations[i].Amount.Cmp(delegateBalance) <= 0 {
-						delegateBalance.Sub(delegateBalance, delegation.Undelegations[i].Amount)
-					} else {
-						delegation.Undelegations[i].Amount.Sub(delegation.Undelegations[i].Amount, delegateBalance)
-						delegateBalance = big.NewInt(0)
-						break
-					}
-				}
-
-				delegation.Undelegations = delegation.Undelegations[:i+1]
-				delegation.Amount.Add(delegation.Amount, delegate.Amount)
-				err := stateDB.UpdateStakingInfo(wrapper.Validator.Address, wrapper)
-
 	if err != nil {
 		return err
 	}
-				// Secondly, if all locked token are used, try use the balance.
+	if err := st.state.UpdateStakingInfo(wrapper.Validator.Address, wrapper); err != nil {
-				if delegateBalance.Cmp(big.NewInt(0)) > 0 {
-					stateDB.SubBalance(delegate.DelegatorAddress, delegateBalance)
-					return nil
-				}
-				// This shouldn't really happen
-				return errInsufficientBalanceForStake
-			}
-			return errors.Wrapf(
-				errInsufficientBalanceForStake,
-				"total-delegated %s own-current-balance %s amount-to-delegate %s",
-				totalInUndelegation.String(),
-				balance.String(),
-				delegate.Amount.String(),
-			)
-		}
-	}
-
-	if !delegatorExist {
-		if CanTransfer(stateDB, delegate.DelegatorAddress, delegate.Amount) {
-			newDelegator := staking.NewDelegation(delegate.DelegatorAddress, delegate.Amount)
-			wrapper.Delegations = append(wrapper.Delegations, newDelegator)
-
-			if err := stateDB.UpdateStakingInfo(wrapper.Validator.Address, wrapper); err == nil {
-				stateDB.SubBalance(delegate.DelegatorAddress, delegate.Amount)
-			} else {
 		return err
 	}
-		}
+	st.state.SubBalance(delegate.DelegatorAddress, balanceToBeDeducted)
-	}
-
 	return nil
 }
 
-func (st *StateTransition) applyUndelegateTx(undelegate *staking.Undelegate) error {
+func (st *StateTransition) verifyAndApplyUndelegateTx(undelegate *staking.Undelegate) error {
-	if undelegate.Amount.Sign() == -1 {
+	wrapper, err := VerifyAndUndelegateFromMsg(st.state, st.evm.EpochNumber, undelegate)
-		return errNegativeAmount
-	}
-
-	if !st.state.IsValidator(undelegate.ValidatorAddress) {
-		return errValidatorNotExist
-	}
-	wrapper := st.state.GetStakingInfo(undelegate.ValidatorAddress)
-	if wrapper == nil {
-		return errValidatorNotExist
-	}
-
-	stateDB := st.state
-	delegatorExist := false
-	for i := range wrapper.Delegations {
-		delegation := &wrapper.Delegations[i]
-		if bytes.Equal(delegation.DelegatorAddress.Bytes(), undelegate.DelegatorAddress.Bytes()) {
-			delegatorExist = true
-
-			err := delegation.Undelegate(st.evm.EpochNumber, undelegate.Amount)
 	if err != nil {
 		return err
 	}
-			err = stateDB.UpdateStakingInfo(wrapper.Validator.Address, wrapper)
+	return st.state.UpdateStakingInfo(wrapper.Validator.Address, wrapper)
-			return err
-		}
-	}
-	if !delegatorExist {
-		return errNoDelegationToUndelegate
-	}
-	return nil
 }
 
-func (st *StateTransition) applyCollectRewards(collectRewards *staking.CollectRewards) error {
+func (st *StateTransition) verifyAndApplyCollectRewards(collectRewards *staking.CollectRewards) error {
 	if st.bc == nil {
 		return errors.New("[CollectRewards] No chain context provided")
 	}
-	chainContext := st.bc
+	delegations, err := st.bc.ReadDelegationsByDelegator(collectRewards.DelegatorAddress)
-	delegations, err := chainContext.ReadDelegationsByDelegator(collectRewards.DelegatorAddress)
-
 	if err != nil {
 		return err
 	}
-
+	updatedValidatorWrappers, totalRewards, err := VerifyAndCollectRewardsFromDelegation(st.state, delegations)
-	totalRewards := big.NewInt(0)
-	for i := range delegations {
-		wrapper := st.state.GetStakingInfo(delegations[i].ValidatorAddress)
-		if wrapper == nil {
-			return errValidatorNotExist
-		}
-
-		if uint64(len(wrapper.Delegations)) > delegations[i].Index {
-			delegation := &wrapper.Delegations[delegations[i].Index]
-			if delegation.Reward.Cmp(big.NewInt(0)) > 0 {
-				totalRewards.Add(totalRewards, delegation.Reward)
-			}
-
-			delegation.Reward.SetUint64(0)
-		}
-
-		err = st.state.UpdateStakingInfo(wrapper.Validator.Address, wrapper)
 	if err != nil {
 		return err
 	}
+	for _, wrapper := range updatedValidatorWrappers {
+		if err := st.state.UpdateStakingInfo(wrapper.Validator.Address, wrapper); err != nil {
+			return err
 		}
-	if totalRewards.Int64() == 0 {
-		return errNoRewardsToCollect
 	}
 	st.state.AddBalance(collectRewards.DelegatorAddress, totalRewards)
 	return nil

core/tx_journal.go

@@ -17,15 +17,22 @@
 package core
 
 import (
-	"errors"
 	"io"
 	"os"
 
+	"github.com/pkg/errors"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/rlp"
 
 	"github.com/harmony-one/harmony/core/types"
 	"github.com/harmony-one/harmony/internal/utils"
+	staking "github.com/harmony-one/harmony/staking/types"
+)
+
+const (
+	plainTxID   = uint64(1)
+	stakingTxID = uint64(2)
 )
 
 // errNoActiveJournal is returned if a transaction is attempted to be inserted
@@ -55,9 +62,26 @@ func newTxJournal(path string) *txJournal {
 	}
 }
 
+// writeJournalTx writes a transaction journal tx to file with a leading uint64
+// to identify the written transaction.
+func writeJournalTx(writer io.WriteCloser, tx types.PoolTransaction) error {
+	if _, ok := tx.(*types.Transaction); ok {
+		if _, err := writer.Write([]byte{byte(plainTxID)}); err != nil {
+			return err
+		}
+	} else if _, ok := tx.(*staking.StakingTransaction); ok {
+		if _, err := writer.Write([]byte{byte(stakingTxID)}); err != nil {
+			return err
+		}
+	} else {
+		return types.ErrUnknownPoolTxType
+	}
+	return tx.EncodeRLP(writer)
+}
+
 // load parses a transaction journal dump from disk, loading its contents into
 // the specified pool.
-func (journal *txJournal) load(add func([]*types.Transaction) []error) error {
+func (journal *txJournal) load(add func(types.PoolTransactions) []error) error {
 	// Skip the parsing if the journal file doesn't exist at all
 	if _, err := os.Stat(journal.path); os.IsNotExist(err) {
 		return nil
@@ -76,11 +100,12 @@ func (journal *txJournal) load(add func([]*types.Transaction) []error) error {
 	// Inject all transactions from the journal into the pool
 	stream := rlp.NewStream(input, 0)
 	total, dropped := 0, 0
+	batch := types.PoolTransactions{}
 
 	// Create a method to load a limited batch of transactions and bump the
 	// appropriate progress counters. Then use this method to load all the
 	// journaled transactions in small-ish batches.
-	loadBatch := func(txs types.Transactions) {
+	loadBatch := func(txs types.PoolTransactions) {
 		for _, err := range add(txs) {
 			if err != nil {
 				utils.Logger().Error().Err(err).Msg("Failed to add journaled transaction")
@@ -88,21 +113,41 @@ func (journal *txJournal) load(add func([]*types.Transaction) []error) error {
 			}
 		}
 	}
-	var (
-		failure error
-		batch   types.Transactions
-	)
 	for {
-		// Parse the next transaction and terminate on error
+		// Parse the next transaction and terminate on errors
-		tx := new(types.Transaction)
+		var tx types.PoolTransaction
-		if err = stream.Decode(tx); err != nil {
+		switch txType, err := stream.Uint(); txType {
-			if err != io.EOF {
+		case plainTxID:
-				failure = err
+			tx = new(types.Transaction)
+		case stakingTxID:
+			tx = new(staking.StakingTransaction)
+		default:
+			if err != nil {
+				if err == io.EOF { // reached end of journal file, exit with no error after loading batch
+					err = nil
+				} else {
+					utils.Logger().Info().
+						Int("transactions", total).
+						Int("dropped", dropped).
+						Msg("Loaded local transaction journal")
+				}
+				if batch.Len() > 0 {
+					loadBatch(batch)
+				}
+				return err
+			}
 		}
+
+		if err = stream.Decode(tx); err != nil {
+			// should never hit EOF here with the leading ID journal tx encoding scheme.
+			utils.Logger().Info().
+				Int("transactions", total).
+				Int("dropped", dropped).
+				Msg("Loaded local transaction journal")
 			if batch.Len() > 0 {
 				loadBatch(batch)
 			}
-			break
+			return err
 		}
 		// New transaction parsed, queue up for later, import if threshold is reached
 		total++
@@ -112,25 +157,19 @@ func (journal *txJournal) load(add func([]*types.Transaction) []error) error {
 			batch = batch[:0]
 		}
 	}
-	utils.Logger().Info().
-		Int("transactions", total).
-		Int("dropped", dropped).
-		Msg("Loaded local transaction journal")
-
-	return failure
 }
 
 // insert adds the specified transaction to the local disk journal.
-func (journal *txJournal) insert(tx *types.Transaction) error {
+func (journal *txJournal) insert(tx types.PoolTransaction) error {
 	if journal.writer == nil {
 		return errNoActiveJournal
 	}
-	return rlp.Encode(journal.writer, tx)
+	return writeJournalTx(journal.writer, tx)
 }
 
 // rotate regenerates the transaction journal based on the current contents of
 // the transaction pool.
-func (journal *txJournal) rotate(all map[common.Address]types.Transactions) error {
+func (journal *txJournal) rotate(all map[common.Address]types.PoolTransactions) error {
 	// Close the current journal (if any is open)
 	if journal.writer != nil {
 		if err := journal.writer.Close(); err != nil {
@@ -146,7 +185,7 @@ func (journal *txJournal) rotate(all map[common.Address]types.Transactions) erro
 	journaled := 0
 	for _, txs := range all {
 		for _, tx := range txs {
-			if err = rlp.Encode(replacement, tx); err != nil {
+			if err = writeJournalTx(replacement, tx); err != nil {
 				replacement.Close()
 				return err
 			}

core/tx_list.go

@@ -51,27 +51,27 @@ func (h *nonceHeap) Pop() interface{} {
 // txSortedMap is a nonce->transaction hash map with a heap based index to allow
 // iterating over the contents in a nonce-incrementing way.
 type txSortedMap struct {
-	items map[uint64]*types.Transaction // Hash map storing the transaction data
+	items map[uint64]types.PoolTransaction // Hash map storing the transaction data
 	index *nonceHeap                       // Heap of nonces of all the stored transactions (non-strict mode)
-	cache types.Transactions            // Cache of the transactions already sorted
+	cache types.PoolTransactions           // Cache of the transactions already sorted
 }
 
 // newTxSortedMap creates a new nonce-sorted transaction map.
 func newTxSortedMap() *txSortedMap {
 	return &txSortedMap{
-		items: make(map[uint64]*types.Transaction),
+		items: make(map[uint64]types.PoolTransaction),
 		index: new(nonceHeap),
 	}
 }
 
 // Get retrieves the current transactions associated with the given nonce.
-func (m *txSortedMap) Get(nonce uint64) *types.Transaction {
+func (m *txSortedMap) Get(nonce uint64) types.PoolTransaction {
 	return m.items[nonce]
 }
 
 // Put inserts a new transaction into the map, also updating the map's nonce
 // index. If a transaction already exists with the same nonce, it's overwritten.
-func (m *txSortedMap) Put(tx *types.Transaction) {
+func (m *txSortedMap) Put(tx types.PoolTransaction) {
 	nonce := tx.Nonce()
 	if m.items[nonce] == nil {
 		heap.Push(m.index, nonce)
@@ -82,8 +82,8 @@ func (m *txSortedMap) Put(tx *types.Transaction) {
 // Forward removes all transactions from the map with a nonce lower than the
 // provided threshold. Every removed transaction is returned for any post-removal
 // maintenance.
-func (m *txSortedMap) Forward(threshold uint64) types.Transactions {
+func (m *txSortedMap) Forward(threshold uint64) types.PoolTransactions {
-	var removed types.Transactions
+	var removed types.PoolTransactions
 
 	// Pop off heap items until the threshold is reached
 	for m.index.Len() > 0 && (*m.index)[0] < threshold {
@@ -100,8 +100,8 @@ func (m *txSortedMap) Forward(threshold uint64) types.Transactions {
 
 // Filter iterates over the list of transactions and removes all of them for which
 // the specified function evaluates to true.
-func (m *txSortedMap) Filter(filter func(*types.Transaction) bool) types.Transactions {
+func (m *txSortedMap) Filter(filter func(types.PoolTransaction) bool) types.PoolTransactions {
-	var removed types.Transactions
+	var removed types.PoolTransactions
 
 	// Collect all the transactions to filter out
 	for nonce, tx := range m.items {
@@ -125,13 +125,13 @@ func (m *txSortedMap) Filter(filter func(*types.Transaction) bool) types.Transac
 
 // Cap places a hard limit on the number of items, returning all transactions
 // exceeding that limit.
-func (m *txSortedMap) Cap(threshold int) types.Transactions {
+func (m *txSortedMap) Cap(threshold int) types.PoolTransactions {
 	// Short circuit if the number of items is under the limit
 	if len(m.items) <= threshold {
 		return nil
 	}
 	// Otherwise gather and drop the highest nonce'd transactions
-	var drops types.Transactions
+	var drops types.PoolTransactions
 
 	sort.Sort(*m.index)
 	for size := len(m.items); size > threshold; size-- {
@@ -176,13 +176,13 @@ func (m *txSortedMap) Remove(nonce uint64) bool {
 // Note, all transactions with nonces lower than start will also be returned to
 // prevent getting into and invalid state. This is not something that should ever
 // happen but better to be self correcting than failing!
-func (m *txSortedMap) Ready(start uint64) types.Transactions {
+func (m *txSortedMap) Ready(start uint64) types.PoolTransactions {
 	// Short circuit if no transactions are available
 	if m.index.Len() == 0 || (*m.index)[0] > start {
 		return nil
 	}
 	// Otherwise start accumulating incremental transactions
-	var ready types.Transactions
+	var ready types.PoolTransactions
 	for next := (*m.index)[0]; m.index.Len() > 0 && (*m.index)[0] == next; next++ {
 		ready = append(ready, m.items[next])
 		delete(m.items, next)
@@ -201,17 +201,17 @@ func (m *txSortedMap) Len() int {
 // Flatten creates a nonce-sorted slice of transactions based on the loosely
 // sorted internal representation. The result of the sorting is cached in case
 // it's requested again before any modifications are made to the contents.
-func (m *txSortedMap) Flatten() types.Transactions {
+func (m *txSortedMap) Flatten() types.PoolTransactions {
 	// If the sorting was not cached yet, create and cache it
 	if m.cache == nil {
-		m.cache = make(types.Transactions, 0, len(m.items))
+		m.cache = make(types.PoolTransactions, 0, len(m.items))
 		for _, tx := range m.items {
 			m.cache = append(m.cache, tx)
 		}
-		sort.Sort(types.TxByNonce(m.cache))
+		sort.Sort(types.PoolTxByNonce(m.cache))
 	}
 	// Copy the cache to prevent accidental modifications
-	txs := make(types.Transactions, len(m.cache))
+	txs := make(types.PoolTransactions, len(m.cache))
 	copy(txs, m.cache)
 	return txs
 }
@@ -240,7 +240,7 @@ func newTxList(strict bool) *txList {
 
 // Overlaps returns whether the transaction specified has the same nonce as one
 // already contained within the list.
-func (l *txList) Overlaps(tx *types.Transaction) bool {
+func (l *txList) Overlaps(tx types.PoolTransaction) bool {
 	return l.txs.Get(tx.Nonce()) != nil
 }
 
@@ -249,7 +249,7 @@ func (l *txList) Overlaps(tx *types.Transaction) bool {
 //
 // If the new transaction is accepted into the list, the lists' cost and gas
 // thresholds are also potentially updated.
-func (l *txList) Add(tx *types.Transaction, priceBump uint64) (bool, *types.Transaction) {
+func (l *txList) Add(tx types.PoolTransaction, priceBump uint64) (bool, types.PoolTransaction) {
 	// If there's an older better transaction, abort
 	old := l.txs.Get(tx.Nonce())
 	if old != nil {
@@ -275,7 +275,7 @@ func (l *txList) Add(tx *types.Transaction, priceBump uint64) (bool, *types.Tran
 // Forward removes all transactions from the list with a nonce lower than the
 // provided threshold. Every removed transaction is returned for any post-removal
 // maintenance.
-func (l *txList) Forward(threshold uint64) types.Transactions {
+func (l *txList) Forward(threshold uint64) types.PoolTransactions {
 	return l.txs.Forward(threshold)
 }
 
@@ -288,7 +288,7 @@ func (l *txList) Forward(threshold uint64) types.Transactions {
 // a point in calculating all the costs or if the balance covers all. If the threshold
 // is lower than the costgas cap, the caps will be reset to a new high after removing
 // the newly invalidated transactions.
-func (l *txList) Filter(costLimit *big.Int, gasLimit uint64) (types.Transactions, types.Transactions) {
+func (l *txList) Filter(costLimit *big.Int, gasLimit uint64) (types.PoolTransactions, types.PoolTransactions) {
 	// If all transactions are below the threshold, short circuit
 	if l.costcap.Cmp(costLimit) <= 0 && l.gascap <= gasLimit {
 		return nil, nil
@@ -297,10 +297,10 @@ func (l *txList) Filter(costLimit *big.Int, gasLimit uint64) (types.Transactions
 	l.gascap = gasLimit
 
 	// Filter out all the transactions above the account's funds
-	removed := l.txs.Filter(func(tx *types.Transaction) bool { return tx.Cost().Cmp(costLimit) > 0 || tx.Gas() > gasLimit })
+	removed := l.txs.Filter(func(tx types.PoolTransaction) bool { return tx.Cost().Cmp(costLimit) > 0 || tx.Gas() > gasLimit })
 
 	// If the list was strict, filter anything above the lowest nonce
-	var invalids types.Transactions
+	var invalids types.PoolTransactions
 
 	if l.strict && len(removed) > 0 {
 		lowest := uint64(math.MaxUint64)
@@ -309,21 +309,21 @@ func (l *txList) Filter(costLimit *big.Int, gasLimit uint64) (types.Transactions
 				lowest = nonce
 			}
 		}
-		invalids = l.txs.Filter(func(tx *types.Transaction) bool { return tx.Nonce() > lowest })
+		invalids = l.txs.Filter(func(tx types.PoolTransaction) bool { return tx.Nonce() > lowest })
 	}
 	return removed, invalids
 }
 
 // Cap places a hard limit on the number of items, returning all transactions
 // exceeding that limit.
-func (l *txList) Cap(threshold int) types.Transactions {
+func (l *txList) Cap(threshold int) types.PoolTransactions {
 	return l.txs.Cap(threshold)
 }
 
 // Remove deletes a transaction from the maintained list, returning whether the
 // transaction was found, and also returning any transaction invalidated due to
 // the deletion (strict mode only).
-func (l *txList) Remove(tx *types.Transaction) (bool, types.Transactions) {
+func (l *txList) Remove(tx types.PoolTransaction) (bool, types.PoolTransactions) {
 	// Remove the transaction from the set
 	nonce := tx.Nonce()
 	if removed := l.txs.Remove(nonce); !removed {
@@ -331,7 +331,7 @@ func (l *txList) Remove(tx *types.Transaction) (bool, types.Transactions) {
 	}
 	// In strict mode, filter out non-executable transactions
 	if l.strict {
-		return true, l.txs.Filter(func(tx *types.Transaction) bool { return tx.Nonce() > nonce })
+		return true, l.txs.Filter(func(tx types.PoolTransaction) bool { return tx.Nonce() > nonce })
 	}
 	return true, nil
 }
@@ -343,7 +343,7 @@ func (l *txList) Remove(tx *types.Transaction) (bool, types.Transactions) {
 // Note, all transactions with nonces lower than start will also be returned to
 // prevent getting into and invalid state. This is not something that should ever
 // happen but better to be self correcting than failing!
-func (l *txList) Ready(start uint64) types.Transactions {
+func (l *txList) Ready(start uint64) types.PoolTransactions {
 	return l.txs.Ready(start)
 }
 
@@ -360,13 +360,13 @@ func (l *txList) Empty() bool {
 // Flatten creates a nonce-sorted slice of transactions based on the loosely
 // sorted internal representation. The result of the sorting is cached in case
 // it's requested again before any modifications are made to the contents.
-func (l *txList) Flatten() types.Transactions {
+func (l *txList) Flatten() types.PoolTransactions {
 	return l.txs.Flatten()
 }
 
 // priceHeap is a heap.Interface implementation over transactions for retrieving
 // price-sorted transactions to discard when the pool fills up.
-type priceHeap []*types.Transaction
+type priceHeap []types.PoolTransaction
 
 func (h priceHeap) Len() int      { return len(h) }
 func (h priceHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
@@ -384,7 +384,7 @@ func (h priceHeap) Less(i, j int) bool {
 }
 
 func (h *priceHeap) Push(x interface{}) {
-	*h = append(*h, x.(*types.Transaction))
+	*h = append(*h, x.(types.PoolTransaction))
 }
 
 func (h *priceHeap) Pop() interface{} {
@@ -412,7 +412,7 @@ func newTxPricedList(all *txLookup) *txPricedList {
 }
 
 // Put inserts a new transaction into the heap.
-func (l *txPricedList) Put(tx *types.Transaction) {
+func (l *txPricedList) Put(tx types.PoolTransaction) {
 	heap.Push(l.items, tx)
 }
 
@@ -429,7 +429,7 @@ func (l *txPricedList) Removed() {
 	reheap := make(priceHeap, 0, l.all.Count())
 
 	l.stales, l.items = 0, &reheap
-	l.all.Range(func(hash common.Hash, tx *types.Transaction) bool {
+	l.all.Range(func(hash common.Hash, tx types.PoolTransaction) bool {
 		*l.items = append(*l.items, tx)
 		return true
 	})
@@ -438,13 +438,13 @@ func (l *txPricedList) Removed() {
 
 // Cap finds all the transactions below the given price threshold, drops them
 // from the priced list and returns them for further removal from the entire pool.
-func (l *txPricedList) Cap(threshold *big.Int, local *accountSet) types.Transactions {
+func (l *txPricedList) Cap(threshold *big.Int, local *accountSet) types.PoolTransactions {
-	drop := make(types.Transactions, 0, 128) // Remote underpriced transactions to drop
+	drop := make(types.PoolTransactions, 0, 128) // Remote underpriced transactions to drop
-	save := make(types.Transactions, 0, 64)  // Local underpriced transactions to keep
+	save := make(types.PoolTransactions, 0, 64)  // Local underpriced transactions to keep
 
 	for len(*l.items) > 0 {
 		// Discard stale transactions if found during cleanup
-		tx := heap.Pop(l.items).(*types.Transaction)
+		tx := heap.Pop(l.items).(types.PoolTransaction)
 		if l.all.Get(tx.Hash()) == nil {
 			l.stales--
 			continue
@@ -469,14 +469,14 @@ func (l *txPricedList) Cap(threshold *big.Int, local *accountSet) types.Transact
 
 // Underpriced checks whether a transaction is cheaper than (or as cheap as) the
 // lowest priced transaction currently being tracked.
-func (l *txPricedList) Underpriced(tx *types.Transaction, local *accountSet) bool {
+func (l *txPricedList) Underpriced(tx types.PoolTransaction, local *accountSet) bool {
 	// Local transactions cannot be underpriced
 	if local.containsTx(tx) {
 		return false
 	}
 	// Discard stale price points if found at the heap start
 	for len(*l.items) > 0 {
-		head := []*types.Transaction(*l.items)[0]
+		head := types.PoolTransactions(*l.items)[0]
 		if l.all.Get(head.Hash()) == nil {
 			l.stales--
 			heap.Pop(l.items)
@@ -489,19 +489,19 @@ func (l *txPricedList) Underpriced(tx *types.Transaction, local *accountSet) boo
 		utils.Logger().Error().Msg("Pricing query for empty pool") // This cannot happen, print to catch programming errors
 		return false
 	}
-	cheapest := []*types.Transaction(*l.items)[0]
+	cheapest := types.PoolTransactions(*l.items)[0]
 	return cheapest.GasPrice().Cmp(tx.GasPrice()) >= 0
 }
 
 // Discard finds a number of most underpriced transactions, removes them from the
 // priced list and returns them for further removal from the entire pool.
-func (l *txPricedList) Discard(count int, local *accountSet) types.Transactions {
+func (l *txPricedList) Discard(count int, local *accountSet) types.PoolTransactions {
-	drop := make(types.Transactions, 0, count) // Remote underpriced transactions to drop
+	drop := make(types.PoolTransactions, 0, count) // Remote underpriced transactions to drop
-	save := make(types.Transactions, 0, 64)    // Local underpriced transactions to keep
+	save := make(types.PoolTransactions, 0, 64)    // Local underpriced transactions to keep
 
 	for len(*l.items) > 0 && count > 0 {
 		// Discard stale transactions if found during cleanup
-		tx := heap.Pop(l.items).(*types.Transaction)
+		tx := heap.Pop(l.items).(types.PoolTransaction)
 		if l.all.Get(tx.Hash()) == nil {
 			l.stales--
 			continue

core/tx_list_test.go

@@ -30,7 +30,7 @@ func TestStrictTxListAdd(t *testing.T) {
 	// Generate a list of transactions to insert
 	key, _ := crypto.GenerateKey()
 
-	txs := make(types.Transactions, 1024)
+	txs := make(types.PoolTransactions, 1024)
 	for i := 0; i < len(txs); i++ {
 		txs[i] = transaction(uint64(i), 0, key)
 	}

core/tx_pool.go

@@ -37,6 +37,8 @@ import (
 	"github.com/harmony-one/harmony/core/types"
 	hmyCommon "github.com/harmony-one/harmony/internal/common"
 	"github.com/harmony-one/harmony/internal/utils"
+	"github.com/harmony-one/harmony/shard"
+	staking "github.com/harmony-one/harmony/staking/types"
 )
 
 const (
@@ -85,6 +87,10 @@ var (
 	// attempting to be added to the pool.
 	ErrKnownTransaction = errors.New("known transaction")
 
+	// ErrInvalidMsgForStakingDirective is returned if a staking message does not
+	// match the related directive
+	ErrInvalidMsgForStakingDirective = errors.New("staking message does not match directive message")
+
 	// ErrBlacklistFrom is returned if a transaction's from/source address is blacklisted
 	ErrBlacklistFrom = errors.New("`from` address of transaction in blacklist")
 
@@ -242,14 +248,17 @@ type TxPool struct {
 
 	wg sync.WaitGroup // for shutdown sync
 
-	txnErrorSink func([]types.RPCTransactionError)
+	errorReporter *txPoolErrorReporter // The reporter for the tx error sinks
 
 	homestead bool
 }
 
 // NewTxPool creates a new transaction pool to gather, sort and filter inbound
 // transactions from the network.
-func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain blockChain, txnErrorSink func([]types.RPCTransactionError)) *TxPool {
+func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain blockChain,
+	txnErrorSink func([]types.RPCTransactionError),
+	stakingTxnErrorSink func([]staking.RPCTransactionError),
+) *TxPool {
 	// Sanitize the input to ensure no vulnerable gas prices are set
 	config = (&config).sanitize()
 
@@ -265,7 +274,7 @@ func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain block
 		all:           newTxLookup(),
 		chainHeadCh:   make(chan ChainHeadEvent, chainHeadChanSize),
 		gasPrice:      new(big.Int).SetUint64(config.PriceLimit),
-		txnErrorSink: txnErrorSink,
+		errorReporter: newTxPoolErrorReporter(txnErrorSink, stakingTxnErrorSink),
 	}
 	pool.locals = newAccountSet(pool.signer)
 	for _, addr := range config.Locals {
@@ -394,7 +403,7 @@ func (pool *TxPool) lockedReset(oldHead, newHead *block.Header) {
 // of the transaction pool is valid with regard to the chain state.
 func (pool *TxPool) reset(oldHead, newHead *block.Header) {
 	// If we're reorging an old state, reinject all dropped transactions
-	var reinject types.Transactions
+	var reinject types.PoolTransactions
 
 	if oldHead != nil && oldHead.Hash() != newHead.ParentHash() {
 		// If the reorg is too deep, avoid doing it (will happen during fast sync)
@@ -405,14 +414,19 @@ func (pool *TxPool) reset(oldHead, newHead *block.Header) {
 			utils.Logger().Debug().Uint64("depth", depth).Msg("Skipping deep transaction reorg")
 		} else {
 			// Reorg seems shallow enough to pull in all transactions into memory
-			var discarded, included types.Transactions
+			var discarded, included types.PoolTransactions
 
 			var (
 				rem = pool.chain.GetBlock(oldHead.Hash(), oldHead.Number().Uint64())
 				add = pool.chain.GetBlock(newHead.Hash(), newHead.Number().Uint64())
 			)
 			for rem.NumberU64() > add.NumberU64() {
-				discarded = append(discarded, rem.Transactions()...)
+				for _, tx := range rem.Transactions() {
+					discarded = append(discarded, tx)
+				}
+				for _, tx := range rem.StakingTransactions() {
+					discarded = append(discarded, tx)
+				}
 				if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
 					utils.Logger().Error().
 						Str("block", oldHead.Number().String()).
@@ -422,7 +436,12 @@ func (pool *TxPool) reset(oldHead, newHead *block.Header) {
 				}
 			}
 			for add.NumberU64() > rem.NumberU64() {
-				included = append(included, add.Transactions()...)
+				for _, tx := range add.Transactions() {
+					included = append(included, tx)
+				}
+				for _, tx := range add.StakingTransactions() {
+					included = append(included, tx)
+				}
 				if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
 					utils.Logger().Error().
 						Str("block", newHead.Number().String()).
@@ -432,7 +451,12 @@ func (pool *TxPool) reset(oldHead, newHead *block.Header) {
 				}
 			}
 			for rem.Hash() != add.Hash() {
-				discarded = append(discarded, rem.Transactions()...)
+				for _, tx := range rem.Transactions() {
+					discarded = append(discarded, tx)
+				}
+				for _, tx := range rem.StakingTransactions() {
+					discarded = append(discarded, tx)
+				}
 				if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
 					utils.Logger().Error().
 						Str("block", oldHead.Number().String()).
@@ -440,7 +464,12 @@ func (pool *TxPool) reset(oldHead, newHead *block.Header) {
 						Msg("Unrooted old chain seen by tx pool")
 					return
 				}
-				included = append(included, add.Transactions()...)
+				for _, tx := range add.Transactions() {
+					included = append(included, tx)
+				}
+				for _, tx := range add.StakingTransactions() {
+					included = append(included, tx)
+				}
 				if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
 					utils.Logger().Error().
 						Str("block", newHead.Number().String()).
@@ -449,7 +478,7 @@ func (pool *TxPool) reset(oldHead, newHead *block.Header) {
 					return
 				}
 			}
-			reinject = types.TxDifference(discarded, included)
+			reinject = types.PoolTxDifference(discarded, included)
 		}
 	}
 	// Initialize the internal state to the current head
@@ -566,15 +595,15 @@ func (pool *TxPool) stats() (int, int) {
 
 // Content retrieves the data content of the transaction pool, returning all the
 // pending as well as queued transactions, grouped by account and sorted by nonce.
-func (pool *TxPool) Content() (map[common.Address]types.Transactions, map[common.Address]types.Transactions) {
+func (pool *TxPool) Content() (map[common.Address]types.PoolTransactions, map[common.Address]types.PoolTransactions) {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
 
-	pending := make(map[common.Address]types.Transactions)
+	pending := make(map[common.Address]types.PoolTransactions)
 	for addr, list := range pool.pending {
 		pending[addr] = list.Flatten()
 	}
-	queued := make(map[common.Address]types.Transactions)
+	queued := make(map[common.Address]types.PoolTransactions)
 	for addr, list := range pool.queue {
 		queued[addr] = list.Flatten()
 	}
@@ -584,11 +613,11 @@ func (pool *TxPool) Content() (map[common.Address]types.Transactions, map[common
 // Pending retrieves all currently processable transactions, grouped by origin
 // account and sorted by nonce. The returned transaction set is a copy and can be
 // freely modified by calling code.
-func (pool *TxPool) Pending() (map[common.Address]types.Transactions, error) {
+func (pool *TxPool) Pending() (map[common.Address]types.PoolTransactions, error) {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
 
-	pending := make(map[common.Address]types.Transactions)
+	pending := make(map[common.Address]types.PoolTransactions)
 	for addr, list := range pool.pending {
 		pending[addr] = list.Flatten()
 	}
@@ -606,8 +635,8 @@ func (pool *TxPool) Locals() []common.Address {
 // local retrieves all currently known local transactions, grouped by origin
 // account and sorted by nonce. The returned transaction set is a copy and can be
 // freely modified by calling code.
-func (pool *TxPool) local() map[common.Address]types.Transactions {
+func (pool *TxPool) local() map[common.Address]types.PoolTransactions {
-	txs := make(map[common.Address]types.Transactions)
+	txs := make(map[common.Address]types.PoolTransactions)
 	for addr := range pool.locals.accounts {
 		if pending := pool.pending[addr]; pending != nil {
 			txs[addr] = append(txs[addr], pending.Flatten()...)
@@ -621,7 +650,7 @@ func (pool *TxPool) local() map[common.Address]types.Transactions {
 
 // validateTx checks whether a transaction is valid according to the consensus
 // rules and adheres to some heuristic limits of the local node (price and size).
-func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
+func (pool *TxPool) validateTx(tx types.PoolTransaction, local bool) error {
 	// Heuristic limit, reject transactions over 32KB to prevent DOS attacks
 	if tx.Size() > 32*1024 {
 		return errors.WithMessagef(ErrOversizedData, "transaction size is %s", tx.Size().String())
@@ -636,7 +665,7 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 		return errors.WithMessagef(ErrGasLimit, "transaction gas is %d", tx.Gas())
 	}
 	// Make sure the transaction is signed properly
-	from, err := types.Sender(pool.signer, tx)
+	from, err := types.PoolTransactionSender(pool.signer, tx)
 	if err != nil {
 		if b32, err := hmyCommon.AddressToBech32(from); err == nil {
 			return errors.WithMessagef(ErrInvalidSender, "transaction sender is %s", b32)
@@ -675,17 +704,131 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 	if pool.currentState.GetBalance(from).Cmp(tx.Cost()) < 0 {
 		return ErrInsufficientFunds
 	}
-	// TODO(Daniel): add support for staking txn - create validator
+	intrGas := uint64(0)
-	intrGas, err := IntrinsicGas(tx.Data(), tx.To() == nil, pool.homestead, false)
+	stakingTx, isStakingTx := tx.(*staking.StakingTransaction)
+	if isStakingTx {
+		intrGas, err = IntrinsicGas(tx.Data(), false, pool.homestead, stakingTx.StakingType() == staking.DirectiveCreateValidator)
+	} else {
+		intrGas, err = IntrinsicGas(tx.Data(), tx.To() == nil, pool.homestead, false)
+	}
 	if err != nil {
 		return err
 	}
 	if tx.Gas() < intrGas {
 		return errors.WithMessagef(ErrIntrinsicGas, "transaction gas is %d", tx.Gas())
 	}
+	// Do more checks if it is a staking transaction
+	if isStakingTx {
+		return pool.validateStakingTx(stakingTx)
+	}
 	return nil
 }
 
+// validateStakingTx checks the staking message based on the staking directive
+func (pool *TxPool) validateStakingTx(tx *staking.StakingTransaction) error {
+	// from address already validated
+	from, _ := types.PoolTransactionSender(pool.signer, tx)
+	b32, _ := hmyCommon.AddressToBech32(from)
+
+	switch tx.StakingType() {
+	case staking.DirectiveCreateValidator:
+		msg, err := staking.RLPDecodeStakeMsg(tx.Data(), staking.DirectiveCreateValidator)
+		if err != nil {
+			return err
+		}
+		stkMsg, ok := msg.(*staking.CreateValidator)
+		if !ok {
+			return ErrInvalidMsgForStakingDirective
+		}
+		if from != stkMsg.ValidatorAddress {
+			return errors.WithMessagef(ErrInvalidSender, "staking transaction sender is %s", b32)
+		}
+		currentBlockNumber := pool.chain.CurrentBlock().Number()
+		pendingBlockNumber := new(big.Int).Add(currentBlockNumber, big.NewInt(1))
+		pendingEpoch := pool.chain.CurrentBlock().Epoch()
+		if shard.Schedule.IsLastBlock(currentBlockNumber.Uint64()) {
+			pendingEpoch = new(big.Int).Add(pendingEpoch, big.NewInt(1))
+		}
+		_, err = VerifyAndCreateValidatorFromMsg(pool.currentState, pendingEpoch, pendingBlockNumber, stkMsg)
+		return err
+	case staking.DirectiveEditValidator:
+		msg, err := staking.RLPDecodeStakeMsg(tx.Data(), staking.DirectiveEditValidator)
+		if err != nil {
+			return err
+		}
+		stkMsg, ok := msg.(*staking.EditValidator)
+		if !ok {
+			return ErrInvalidMsgForStakingDirective
+		}
+		if from != stkMsg.ValidatorAddress {
+			return errors.WithMessagef(ErrInvalidSender, "staking transaction sender is %s", b32)
+		}
+		chainContext, ok := pool.chain.(ChainContext)
+		if !ok {
+			chainContext = nil // might use testing blockchain, set to nil for verifier to handle.
+		}
+		pendingBlockNumber := new(big.Int).Add(pool.chain.CurrentBlock().Number(), big.NewInt(1))
+		_, err = VerifyAndEditValidatorFromMsg(pool.currentState, chainContext, pendingBlockNumber, stkMsg)
+		return err
+	case staking.DirectiveDelegate:
+		msg, err := staking.RLPDecodeStakeMsg(tx.Data(), staking.DirectiveDelegate)
+		if err != nil {
+			return err
+		}
+		stkMsg, ok := msg.(*staking.Delegate)
+		if !ok {
+			return ErrInvalidMsgForStakingDirective
+		}
+		if from != stkMsg.DelegatorAddress {
+			return errors.WithMessagef(ErrInvalidSender, "staking transaction sender is %s", b32)
+		}
+		_, _, err = VerifyAndDelegateFromMsg(pool.currentState, stkMsg)
+		return err
+	case staking.DirectiveUndelegate:
+		msg, err := staking.RLPDecodeStakeMsg(tx.Data(), staking.DirectiveUndelegate)
+		if err != nil {
+			return err
+		}
+		stkMsg, ok := msg.(*staking.Undelegate)
+		if !ok {
+			return ErrInvalidMsgForStakingDirective
+		}
+		if from != stkMsg.DelegatorAddress {
+			return errors.WithMessagef(ErrInvalidSender, "staking transaction sender is %s", b32)
+		}
+		pendingEpoch := pool.chain.CurrentBlock().Epoch()
+		if shard.Schedule.IsLastBlock(pool.chain.CurrentBlock().Number().Uint64()) {
+			pendingEpoch = new(big.Int).Add(pendingEpoch, big.NewInt(1))
+		}
+		_, err = VerifyAndUndelegateFromMsg(pool.currentState, pendingEpoch, stkMsg)
+		return err
+	case staking.DirectiveCollectRewards:
+		msg, err := staking.RLPDecodeStakeMsg(tx.Data(), staking.DirectiveCollectRewards)
+		if err != nil {
+			return err
+		}
+		stkMsg, ok := msg.(*staking.CollectRewards)
+		if !ok {
+			return ErrInvalidMsgForStakingDirective
+		}
+		if from != stkMsg.DelegatorAddress {
+			return errors.WithMessagef(ErrInvalidSender, "staking transaction sender is %s", b32)
+		}
+		chain, ok := pool.chain.(ChainContext)
+		if !ok {
+			return nil // for testing, chain could be testing blockchain
+		}
+		delegations, err := chain.ReadDelegationsByDelegator(stkMsg.DelegatorAddress)
+		if err != nil {
+			return err
+		}
+		_, _, err = VerifyAndCollectRewardsFromDelegation(pool.currentState, delegations)
+		return err
+	default:
+		return staking.ErrInvalidStakingKind
+	}
+}
+
 // add validates a transaction and inserts it into the non-executable queue for
 // later pending promotion and execution. If the transaction is a replacement for
 // an already pending or queued one, it overwrites the previous and returns this
@@ -694,7 +837,7 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 // If a newly added transaction is marked as local, its sending account will be
 // whitelisted, preventing any associated transaction from being dropped out of
 // the pool due to pricing constraints.
-func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
+func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 	logger := utils.Logger().With().Stack().Logger()
 	// If the transaction is already known, discard it
 	hash := tx.Hash()
@@ -733,7 +876,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 		}
 	}
 	// If the transaction is replacing an already pending one, do directly
-	from, _ := types.Sender(pool.signer, tx) // already validated
+	from, _ := types.PoolTransactionSender(pool.signer, tx) // already validated
 	if list := pool.pending[from]; list != nil && list.Overlaps(tx) {
 		// Nonce already pending, check if required price bump is met
 		inserted, old := list.Add(tx, pool.config.PriceBump)
@@ -758,7 +901,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 			Msg("Pooled new executable transaction")
 
 		// We've directly injected a replacement transaction, notify subsystems
-		// go pool.txFeed.Send(NewTxsEvent{types.Transactions{tx}})
+		// go pool.txFeed.Send(NewTxsEvent{types.PoolTransactions{tx}})
 
 		return old != nil, nil
 	}
@@ -786,7 +929,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 
 // Add adds a transaction to the pool if valid and passes it to the tx relay
 // backend
-func (pool *TxPool) Add(ctx context.Context, tx *types.Transaction) error {
+func (pool *TxPool) Add(ctx context.Context, tx *types.PoolTransaction) error {
 	// TODO(ricl): placeholder
 	// TODO(minhdoan): follow with richard why we need this. As of now TxPool is not used now.
 	return nil
@@ -795,9 +938,9 @@ func (pool *TxPool) Add(ctx context.Context, tx *types.Transaction) error {
 // enqueueTx inserts a new transaction into the non-executable transaction queue.
 //
 // Note, this method assumes the pool lock is held!
-func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) (bool, error) {
+func (pool *TxPool) enqueueTx(hash common.Hash, tx types.PoolTransaction) (bool, error) {
 	// Try to insert the transaction into the future queue
-	from, _ := types.Sender(pool.signer, tx) // already validated
+	from, _ := types.PoolTransactionSender(pool.signer, tx) // already validated
 	if pool.queue[from] == nil {
 		pool.queue[from] = newTxList(false)
 	}
@@ -822,7 +965,7 @@ func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) (bool, er
 
 // journalTx adds the specified transaction to the local disk journal if it is
 // deemed to have been sent from a local account.
-func (pool *TxPool) journalTx(from common.Address, tx *types.Transaction) {
+func (pool *TxPool) journalTx(from common.Address, tx types.PoolTransaction) {
 	// Only journal if it's enabled and the transaction is local
 	if pool.journal == nil || !pool.locals.contains(from) {
 		return
@@ -836,7 +979,7 @@ func (pool *TxPool) journalTx(from common.Address, tx *types.Transaction) {
 // and returns whether it was inserted or an older was better.
 //
 // Note, this method assumes the pool lock is held!
-func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.Transaction) bool {
+func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx types.PoolTransaction) bool {
 	// Try to insert the transaction into the pending queue
 	if pool.pending[addr] == nil {
 		pool.pending[addr] = newTxList(true)
@@ -874,33 +1017,33 @@ func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.T
 // AddLocal enqueues a single transaction into the pool if it is valid, marking
 // the sender as a local one in the mean time, ensuring it goes around the local
 // pricing constraints.
-func (pool *TxPool) AddLocal(tx *types.Transaction) error {
+func (pool *TxPool) AddLocal(tx types.PoolTransaction) error {
 	return pool.addTx(tx, !pool.config.NoLocals)
 }
 
 // AddRemote enqueues a single transaction into the pool if it is valid. If the
 // sender is not among the locally tracked ones, full pricing constraints will
 // apply.
-func (pool *TxPool) AddRemote(tx *types.Transaction) error {
+func (pool *TxPool) AddRemote(tx types.PoolTransaction) error {
 	return pool.addTx(tx, false)
 }
 
 // AddLocals enqueues a batch of transactions into the pool if they are valid,
 // marking the senders as a local ones in the mean time, ensuring they go around
 // the local pricing constraints.
-func (pool *TxPool) AddLocals(txs []*types.Transaction) []error {
+func (pool *TxPool) AddLocals(txs types.PoolTransactions) []error {
 	return pool.addTxs(txs, !pool.config.NoLocals)
 }
 
 // AddRemotes enqueues a batch of transactions into the pool if they are valid.
 // If the senders are not among the locally tracked ones, full pricing constraints
 // will apply.
-func (pool *TxPool) AddRemotes(txs []*types.Transaction) []error {
+func (pool *TxPool) AddRemotes(txs types.PoolTransactions) []error {
 	return pool.addTxs(txs, false)
 }
 
 // addTx enqueues a single transaction into the pool if it is valid.
-func (pool *TxPool) addTx(tx *types.Transaction, local bool) error {
+func (pool *TxPool) addTx(tx types.PoolTransaction, local bool) error {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
 
@@ -909,20 +1052,24 @@ func (pool *TxPool) addTx(tx *types.Transaction, local bool) error {
 	if err != nil {
 		errCause := errors.Cause(err)
 		if errCause != ErrKnownTransaction {
-			pool.txnErrorSink([]types.RPCTransactionError{*types.NewRPCTransactionError(tx.Hash(), err)})
+			pool.errorReporter.add(tx, err)
 		}
 		return errCause
 	}
 	// If we added a new transaction, run promotion checks and return
 	if !replace {
-		from, _ := types.Sender(pool.signer, tx) // already validated
+		from, _ := types.PoolTransactionSender(pool.signer, tx) // already validated
 		pool.promoteExecutables([]common.Address{from})
 	}
+	if err := pool.errorReporter.report(); err != nil {
+		utils.Logger().Error().Err(err).
+			Msg("could not report failed transactions in tx pool when adding 1 tx")
+	}
 	return nil
 }
 
 // addTxs attempts to queue a batch of transactions if they are valid.
-func (pool *TxPool) addTxs(txs []*types.Transaction, local bool) []error {
+func (pool *TxPool) addTxs(txs types.PoolTransactions, local bool) []error {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
 
@@ -931,22 +1078,22 @@ func (pool *TxPool) addTxs(txs []*types.Transaction, local bool) []error {
 
 // addTxsLocked attempts to queue a batch of transactions if they are valid,
 // whilst assuming the transaction pool lock is already held.
-func (pool *TxPool) addTxsLocked(txs []*types.Transaction, local bool) []error {
+func (pool *TxPool) addTxsLocked(txs types.PoolTransactions, local bool) []error {
 	// Add the batch of transaction, tracking the accepted ones
 	dirty := make(map[common.Address]struct{})
-	errs := make([]error, len(txs))
+	errs := make([]error, txs.Len())
-	erroredTxns := []types.RPCTransactionError{}
 
 	for i, tx := range txs {
 		replace, err := pool.add(tx, local)
 		if err == nil && !replace {
-			from, _ := types.Sender(pool.signer, tx) // already validated
+			from, _ := types.PoolTransactionSender(pool.signer, tx) // already validated
 			dirty[from] = struct{}{}
 		}
-		if err != nil && err != ErrKnownTransaction {
+		errCause := errors.Cause(err)
-			erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
+		if err != nil && errCause != ErrKnownTransaction {
+			pool.errorReporter.add(tx, err)
 		}
-		errs[i] = errors.Cause(err)
+		errs[i] = errCause
 	}
 	// Only reprocess the internal state if something was actually added
 	if len(dirty) > 0 {
@@ -957,7 +1104,10 @@ func (pool *TxPool) addTxsLocked(txs []*types.Transaction, local bool) []error {
 		pool.promoteExecutables(addrs)
 	}
 
-	pool.txnErrorSink(erroredTxns)
+	if err := pool.errorReporter.report(); err != nil {
+		utils.Logger().Error().Err(err).
+			Msg("could not report failed transactions in tx pool when adding txs")
+	}
 	return errs
 }
 
@@ -970,7 +1120,7 @@ func (pool *TxPool) Status(hashes []common.Hash) []TxStatus {
 	status := make([]TxStatus, len(hashes))
 	for i, hash := range hashes {
 		if tx := pool.all.Get(hash); tx != nil {
-			from, _ := types.Sender(pool.signer, tx) // already validated
+			from, _ := types.PoolTransactionSender(pool.signer, tx) // already validated
 			if pool.pending[from] != nil && pool.pending[from].txs.items[tx.Nonce()] != nil {
 				status[i] = TxStatusPending
 			} else {
@@ -983,7 +1133,7 @@ func (pool *TxPool) Status(hashes []common.Hash) []TxStatus {
 
 // Get returns a transaction if it is contained in the pool
 // and nil otherwise.
-func (pool *TxPool) Get(hash common.Hash) *types.Transaction {
+func (pool *TxPool) Get(hash common.Hash) types.PoolTransaction {
 	return pool.all.Get(hash)
 }
 
@@ -995,7 +1145,7 @@ func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 	if tx == nil {
 		return
 	}
-	addr, _ := types.Sender(pool.signer, tx) // already validated during insertion
+	addr, _ := types.PoolTransactionSender(pool.signer, tx) // already validated during insertion
 
 	// Remove it from the list of known transactions
 	pool.all.Remove(hash)
@@ -1012,7 +1162,9 @@ func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 			}
 			// Postpone any invalidated transactions
 			for _, tx := range invalids {
-				pool.enqueueTx(tx.Hash(), tx)
+				if _, err := pool.enqueueTx(tx.Hash(), tx); err != nil {
+					pool.errorReporter.add(tx, err)
+				}
 			}
 			// Update the account nonce if needed
 			if nonce := tx.Nonce(); pool.pendingState.GetNonce(addr) > nonce {
@@ -1028,6 +1180,11 @@ func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 			delete(pool.queue, addr)
 		}
 	}
+
+	if err := pool.errorReporter.report(); err != nil {
+		utils.Logger().Error().Err(err).
+			Msg("could not report failed transactions in tx pool when removing tx from queue")
+	}
 }
 
 // promoteExecutables moves transactions that have become processable from the
@@ -1035,9 +1192,8 @@ func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 // invalidated transactions (low nonce, low balance) are deleted.
 func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 	// Track the promoted transactions to broadcast them at once
-	var promoted []*types.Transaction
+	var promoted types.PoolTransactions
 	logger := utils.Logger().With().Stack().Logger()
-	erroredTxns := []types.RPCTransactionError{}
 
 	// Gather all the accounts potentially needing updates
 	if accounts == nil {
@@ -1057,10 +1213,6 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		for _, tx := range list.Forward(nonce) {
 			hash := tx.Hash()
 			logger.Warn().Str("hash", hash.Hex()).Msg("Removed old queued transaction")
-			if pool.chain.CurrentBlock().Transaction(hash) == nil {
-				err := fmt.Errorf("old transaction, nonce %d is too low", nonce)
-				erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
-			}
 			pool.all.Remove(hash)
 			pool.priced.Removed()
 		}
@@ -1069,8 +1221,6 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		for _, tx := range drops {
 			hash := tx.Hash()
 			logger.Warn().Str("hash", hash.Hex()).Msg("Removed unpayable queued transaction")
-			err := fmt.Errorf("unpayable transaction, out of gas or balance of %d cannot pay cost of %d", tx.Value(), tx.Cost())
-			erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
 			pool.all.Remove(hash)
 			pool.priced.Removed()
 			queuedNofundsCounter.Inc(1)
@@ -1088,8 +1238,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 			for _, tx := range list.Cap(int(pool.config.AccountQueue)) {
 				hash := tx.Hash()
 				logger.Warn().Str("hash", hash.Hex()).Msg("Removed cap-exceeding queued transaction")
-				err := fmt.Errorf("exceeds cap for queued transactions for account %s", addr.String())
+				pool.errorReporter.add(tx, fmt.Errorf("exceeds cap for queued transactions for account %s", addr.String()))
-				erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
 				pool.all.Remove(hash)
 				pool.priced.Removed()
 				queuedRateLimitCounter.Inc(1)
@@ -1138,8 +1287,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 						for _, tx := range list.Cap(list.Len() - 1) {
 							// Drop the transaction from the global pools too
 							hash := tx.Hash()
-							err := fmt.Errorf("fairness-exceeding pending transaction")
+							pool.errorReporter.add(tx, fmt.Errorf("fairness-exceeding pending transaction"))
-							erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
 							pool.all.Remove(hash)
 							pool.priced.Removed()
 
@@ -1162,8 +1310,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 					for _, tx := range list.Cap(list.Len() - 1) {
 						// Drop the transaction from the global pools too
 						hash := tx.Hash()
-						err := fmt.Errorf("fairness-exceeding pending transaction")
+						pool.errorReporter.add(tx, fmt.Errorf("fairness-exceeding pending transaction"))
-						erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
 						pool.all.Remove(hash)
 						pool.priced.Removed()
 
@@ -1204,8 +1351,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 			// Drop all transactions if they are less than the overflow
 			if size := uint64(list.Len()); size <= drop {
 				for _, tx := range list.Flatten() {
-					err := fmt.Errorf("exceeds global cap for queued transactions")
+					pool.errorReporter.add(tx, fmt.Errorf("exceeds global cap for queued transactions"))
-					erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
 					pool.removeTx(tx.Hash(), true)
 				}
 				drop -= size
@@ -1215,8 +1361,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 			// Otherwise drop only last few transactions
 			txs := list.Flatten()
 			for i := len(txs) - 1; i >= 0 && drop > 0; i-- {
-				err := fmt.Errorf("exceeds global cap for queued transactions")
+				pool.errorReporter.add(txs[i], fmt.Errorf("exceeds global cap for queued transactions"))
-				erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(txs[i].Hash(), err))
 				pool.removeTx(txs[i].Hash(), true)
 				drop--
 				queuedRateLimitCounter.Inc(1)
@@ -1224,7 +1369,10 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		}
 	}
 
-	pool.txnErrorSink(erroredTxns)
+	if err := pool.errorReporter.report(); err != nil {
+		logger.Error().Err(err).
+			Msg("could not report failed transactions in tx pool when promoting executables")
+	}
 }
 
 // demoteUnexecutables removes invalid and processed transactions from the pools
@@ -1233,7 +1381,6 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 func (pool *TxPool) demoteUnexecutables() {
 	// Iterate over all accounts and demote any non-executable transactions
 	logger := utils.Logger().With().Stack().Logger()
-	erroredTxns := []types.RPCTransactionError{}
 
 	for addr, list := range pool.pending {
 		nonce := pool.currentState.GetNonce(addr)
@@ -1242,10 +1389,6 @@ func (pool *TxPool) demoteUnexecutables() {
 		for _, tx := range list.Forward(nonce) {
 			hash := tx.Hash()
 			logger.Warn().Str("hash", hash.Hex()).Msg("Removed old pending transaction")
-			if pool.chain.CurrentBlock().Transaction(hash) == nil {
-				err := fmt.Errorf("old transaction, nonce %d is too low", nonce)
-				erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
-			}
 			pool.all.Remove(hash)
 			pool.priced.Removed()
 		}
@@ -1254,8 +1397,6 @@ func (pool *TxPool) demoteUnexecutables() {
 		for _, tx := range drops {
 			hash := tx.Hash()
 			logger.Warn().Str("hash", hash.Hex()).Msg("Removed unpayable pending transaction")
-			err := fmt.Errorf("unpayable transaction, out of gas or balance of %d cannot pay cost of %d", tx.Value(), tx.Cost())
-			erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
 			pool.all.Remove(hash)
 			pool.priced.Removed()
 			pendingNofundsCounter.Inc(1)
@@ -1263,18 +1404,18 @@ func (pool *TxPool) demoteUnexecutables() {
 		for _, tx := range invalids {
 			hash := tx.Hash()
 			logger.Warn().Str("hash", hash.Hex()).Msg("Demoting pending transaction")
-			err := fmt.Errorf("demoting pending transaction")
+			if _, err := pool.enqueueTx(hash, tx); err != nil {
-			erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
+				pool.errorReporter.add(tx, err)
-			pool.enqueueTx(hash, tx)
+			}
 		}
 		// If there's a gap in front, alert (should never happen) and postpone all transactions
 		if list.Len() > 0 && list.txs.Get(nonce) == nil {
 			for _, tx := range list.Cap(0) {
 				hash := tx.Hash()
 				logger.Error().Str("hash", hash.Hex()).Msg("Demoting invalidated transaction")
-				err := fmt.Errorf("demoting invalid transaction")
+				if _, err := pool.enqueueTx(hash, tx); err != nil {
-				erroredTxns = append(erroredTxns, *types.NewRPCTransactionError(tx.Hash(), err))
+					pool.errorReporter.add(tx, err)
-				pool.enqueueTx(hash, tx)
+				}
 			}
 		}
 		// Delete the entire queue entry if it became empty.
@@ -1283,8 +1424,61 @@ func (pool *TxPool) demoteUnexecutables() {
 			delete(pool.beats, addr)
 		}
 
-		pool.txnErrorSink(erroredTxns)
+		if err := pool.errorReporter.report(); err != nil {
+			logger.Error().Err(err).
+				Msg("could not report failed transactions in tx pool when demoting unexecutables")
+		}
+	}
+}
+
+// txPoolErrorReporter holds and reports transaction errors in the tx-pool.
+// Format assumes that error i in errors corresponds to transaction i in transactions.
+type txPoolErrorReporter struct {
+	transactions          types.PoolTransactions
+	errors                []error
+	txnErrorReportSink    func([]types.RPCTransactionError)
+	stkTxnErrorReportSink func([]staking.RPCTransactionError)
+}
+
+func newTxPoolErrorReporter(txnErrorSink func([]types.RPCTransactionError),
+	stakingTxnErrorSink func([]staking.RPCTransactionError),
+) *txPoolErrorReporter {
+	return &txPoolErrorReporter{
+		transactions:          types.PoolTransactions{},
+		errors:                []error{},
+		txnErrorReportSink:    txnErrorSink,
+		stkTxnErrorReportSink: stakingTxnErrorSink,
+	}
+}
+
+func (txErrs *txPoolErrorReporter) add(tx types.PoolTransaction, err error) {
+	txErrs.transactions = append(txErrs.transactions, tx)
+	txErrs.errors = append(txErrs.errors, err)
+}
+
+func (txErrs *txPoolErrorReporter) reset() {
+	txErrs.transactions = types.PoolTransactions{}
+	txErrs.errors = []error{}
+}
+
+// report errors thrown in the tx pool to the appropriate error sink.
+// It resets the held errors after the errors are reported to the sink.
+func (txErrs *txPoolErrorReporter) report() error {
+	plainTxErrors := []types.RPCTransactionError{}
+	stakingTxErrors := []staking.RPCTransactionError{}
+	for i, tx := range txErrs.transactions {
+		if plainTx, ok := tx.(*types.Transaction); ok {
+			plainTxErrors = append(plainTxErrors, types.NewRPCTransactionError(plainTx.Hash(), txErrs.errors[i]))
+		} else if stakingTx, ok := tx.(*staking.StakingTransaction); ok {
+			stakingTxErrors = append(stakingTxErrors, staking.NewRPCTransactionError(stakingTx.Hash(), stakingTx.StakingType(), txErrs.errors[i]))
+		} else {
+			return types.ErrUnknownPoolTxType
 		}
+	}
+	txErrs.txnErrorReportSink(plainTxErrors)
+	txErrs.stkTxnErrorReportSink(stakingTxErrors)
+	txErrs.reset()
+	return nil
 }
 
 // addressByHeartbeat is an account address tagged with its last activity timestamp.
@@ -1324,8 +1518,8 @@ func (as *accountSet) contains(addr common.Address) bool {
 
 // containsTx checks if the sender of a given tx is within the set. If the sender
 // cannot be derived, this method returns false.
-func (as *accountSet) containsTx(tx *types.Transaction) bool {
+func (as *accountSet) containsTx(tx types.PoolTransaction) bool {
-	if addr, err := types.Sender(as.signer, tx); err == nil {
+	if addr, err := types.PoolTransactionSender(as.signer, tx); err == nil {
 		return as.contains(addr)
 	}
 	return false
@@ -1360,19 +1554,19 @@ func (as *accountSet) flatten() []common.Address {
 // peeking into the pool in TxPool.Get without having to acquire the widely scoped
 // TxPool.mu mutex.
 type txLookup struct {
-	all  map[common.Hash]*types.Transaction
+	all  map[common.Hash]types.PoolTransaction
 	lock sync.RWMutex
 }
 
 // newTxLookup returns a new txLookup structure.
 func newTxLookup() *txLookup {
 	return &txLookup{
-		all: make(map[common.Hash]*types.Transaction),
+		all: make(map[common.Hash]types.PoolTransaction),
 	}
 }
 
 // Range calls f on each key and value present in the map.
-func (t *txLookup) Range(f func(hash common.Hash, tx *types.Transaction) bool) {
+func (t *txLookup) Range(f func(hash common.Hash, tx types.PoolTransaction) bool) {
 	t.lock.RLock()
 	defer t.lock.RUnlock()
 
@@ -1384,7 +1578,7 @@ func (t *txLookup) Range(f func(hash common.Hash, tx *types.Transaction) bool) {
 }
 
 // Get returns a transaction if it exists in the lookup, or nil if not found.
-func (t *txLookup) Get(hash common.Hash) *types.Transaction {
+func (t *txLookup) Get(hash common.Hash) types.PoolTransaction {
 	t.lock.RLock()
 	defer t.lock.RUnlock()
 
@@ -1400,7 +1594,7 @@ func (t *txLookup) Count() int {
 }
 
 // Add adds a transaction to the lookup.
-func (t *txLookup) Add(tx *types.Transaction) {
+func (t *txLookup) Add(tx types.PoolTransaction) {
 	t.lock.Lock()
 	defer t.lock.Unlock()
 

core/tx_pool_test.go

@@ -30,16 +30,24 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
+	"github.com/harmony-one/bls/ffi/go/bls"
 	blockfactory "github.com/harmony-one/harmony/block/factory"
 	"github.com/harmony-one/harmony/common/denominations"
 	"github.com/harmony-one/harmony/core/state"
 	"github.com/harmony-one/harmony/core/types"
+	"github.com/harmony-one/harmony/crypto/hash"
 	"github.com/harmony-one/harmony/internal/params"
+	"github.com/harmony-one/harmony/numeric"
+	"github.com/harmony-one/harmony/shard"
+	staking "github.com/harmony-one/harmony/staking/types"
 )
 
-// testTxPoolConfig is a transaction pool configuration without stateful disk
+var (
-// sideeffects used during testing.
+	// testTxPoolConfig is a transaction pool configuration without stateful disk sideeffects used during testing.
-var testTxPoolConfig TxPoolConfig
+	testTxPoolConfig TxPoolConfig
+	testBLSPubKey    = "30b2c38b1316da91e068ac3bd8751c0901ef6c02a1d58bc712104918302c6ed03d5894671d0c816dad2b4d303320f202"
+	testBLSPrvKey    = "c6d7603520311f7a4e6aac0b26701fc433b75b38df504cd416ef2b900cd66205"
+)
 
 func init() {
 	testTxPoolConfig = DefaultTxPoolConfig
@@ -70,21 +78,67 @@ func (bc *testBlockChain) SubscribeChainHeadEvent(ch chan<- ChainHeadEvent) even
 	return bc.chainHeadFeed.Subscribe(ch)
 }
 
-func transaction(nonce uint64, gaslimit uint64, key *ecdsa.PrivateKey) *types.Transaction {
+// TODO: more staking tests in tx pool & testing lib
+func stakingCreateValidatorTransaction(key *ecdsa.PrivateKey) (*staking.StakingTransaction, error) {
+	stakePayloadMaker := func() (staking.Directive, interface{}) {
+		p := &bls.PublicKey{}
+		p.DeserializeHexStr(testBLSPubKey)
+		pub := shard.BlsPublicKey{}
+		pub.FromLibBLSPublicKey(p)
+		messageBytes := []byte(staking.BlsVerificationStr)
+		privateKey := &bls.SecretKey{}
+		privateKey.DeserializeHexStr(testBLSPrvKey)
+		msgHash := hash.Keccak256(messageBytes)
+		signature := privateKey.SignHash(msgHash[:])
+		var sig shard.BLSSignature
+		copy(sig[:], signature.Serialize())
+
+		ra, _ := numeric.NewDecFromStr("0.7")
+		maxRate, _ := numeric.NewDecFromStr("1")
+		maxChangeRate, _ := numeric.NewDecFromStr("0.5")
+		return staking.DirectiveCreateValidator, staking.CreateValidator{
+			Description: staking.Description{
+				Name:            "SuperHero",
+				Identity:        "YouWouldNotKnow",
+				Website:         "Secret Website",
+				SecurityContact: "LicenseToKill",
+				Details:         "blah blah blah",
+			},
+			CommissionRates: staking.CommissionRates{
+				Rate:          ra,
+				MaxRate:       maxRate,
+				MaxChangeRate: maxChangeRate,
+			},
+			MinSelfDelegation:  big.NewInt(1e18),
+			MaxTotalDelegation: big.NewInt(3e18),
+			ValidatorAddress:   crypto.PubkeyToAddress(key.PublicKey),
+			SlotPubKeys:        []shard.BlsPublicKey{pub},
+			SlotKeySigs:        []shard.BLSSignature{sig},
+			Amount:             big.NewInt(1e18),
+		}
+	}
+
+	gasPrice := big.NewInt(10000)
+	tx, _ := staking.NewStakingTransaction(0, 1e10, gasPrice, stakePayloadMaker)
+	return staking.Sign(tx, staking.NewEIP155Signer(tx.ChainID()), key)
+}
+
+func transaction(nonce uint64, gaslimit uint64, key *ecdsa.PrivateKey) types.PoolTransaction {
 	return pricedTransaction(nonce, gaslimit, big.NewInt(1), key)
 }
 
-func pricedTransaction(nonce uint64, gaslimit uint64, gasprice *big.Int, key *ecdsa.PrivateKey) *types.Transaction {
+func pricedTransaction(nonce uint64, gaslimit uint64, gasprice *big.Int, key *ecdsa.PrivateKey) types.PoolTransaction {
-	tx, _ := types.SignTx(types.NewTransaction(nonce, common.Address{}, 0, big.NewInt(100), gaslimit, gasprice, nil), types.HomesteadSigner{}, key)
+	signedTx, _ := types.SignTx(types.NewTransaction(nonce, common.Address{}, 0, big.NewInt(100), gaslimit, gasprice, nil), types.HomesteadSigner{}, key)
-	return tx
+	return signedTx
 }
 
 func setupTxPool() (*TxPool, *ecdsa.PrivateKey) {
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
-	blockchain := &testBlockChain{statedb, 1000000, new(event.Feed)}
+	blockchain := &testBlockChain{statedb, 1e18, new(event.Feed)}
 
 	key, _ := crypto.GenerateKey()
-	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 
 	return pool, key
 }
@@ -146,8 +200,8 @@ func validateEvents(events chan NewTxsEvent, count int) error {
 	return nil
 }
 
-func deriveSender(tx *types.Transaction) (common.Address, error) {
+func deriveSender(tx types.PoolTransaction) (common.Address, error) {
-	return types.Sender(types.HomesteadSigner{}, tx)
+	return types.PoolTransactionSender(types.HomesteadSigner{}, tx)
 }
 
 type testChain struct {
@@ -194,7 +248,8 @@ func TestStateChangeDuringTransactionPoolReset(t *testing.T) {
 	tx0 := transaction(0, 100000, key)
 	tx1 := transaction(1, 100000, key)
 
-	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	nonce := pool.State().GetNonce(address)
@@ -202,7 +257,7 @@ func TestStateChangeDuringTransactionPoolReset(t *testing.T) {
 		t.Fatalf("Invalid nonce, want 0, got %d", nonce)
 	}
 
-	pool.AddRemotes(types.Transactions{tx0, tx1})
+	pool.AddRemotes(types.PoolTransactions{tx0, tx1})
 
 	nonce = pool.State().GetNonce(address)
 	if nonce != 2 {
@@ -261,6 +316,65 @@ func TestInvalidTransactions(t *testing.T) {
 	}
 }
 
+func TestCreateValidatorTransaction(t *testing.T) {
+	t.Parallel()
+
+	pool, _ := setupTxPool()
+	defer pool.Stop()
+
+	fromKey, _ := crypto.GenerateKey()
+	stx, err := stakingCreateValidatorTransaction(fromKey)
+	if err != nil {
+		t.Errorf("cannot create new staking transaction, %v\n", err)
+	}
+	senderAddr, _ := stx.SenderAddress()
+	pool.currentState.AddBalance(senderAddr, big.NewInt(1e18))
+
+	err = pool.AddRemote(stx)
+	if err != nil {
+		t.Error(err.Error())
+	}
+
+	if pool.pending[senderAddr] == nil || pool.pending[senderAddr].Len() != 1 {
+		t.Error("Expected 1 pending transaction")
+	}
+}
+
+func TestMixedTransactions(t *testing.T) {
+	t.Parallel()
+
+	pool, _ := setupTxPool()
+	defer pool.Stop()
+
+	fromKey, _ := crypto.GenerateKey()
+	stx, err := stakingCreateValidatorTransaction(fromKey)
+	if err != nil {
+		t.Errorf("cannot create new staking transaction, %v\n", err)
+	}
+	stxAddr, _ := stx.SenderAddress()
+	pool.currentState.AddBalance(stxAddr, big.NewInt(1e18))
+
+	goodFromKey, _ := crypto.GenerateKey()
+	tx := transaction(0, 25000, goodFromKey)
+	txAddr, _ := deriveSender(tx)
+	pool.currentState.AddBalance(txAddr, big.NewInt(50100))
+
+	errs := pool.AddRemotes(types.PoolTransactions{stx, tx})
+	for _, err := range errs {
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	if pool.pending[stxAddr] == nil || pool.pending[stxAddr].Len() != 1 {
+		t.Error("Expected 1 pending transaction")
+	}
+
+	if pool.pending[txAddr] == nil || pool.pending[txAddr].Len() != 1 {
+		t.Error("Expected 1 pending transaction")
+	}
+}
+
 func TestBlacklistedTransactions(t *testing.T) {
 	// DO NOT parallelize, test will add accounts to tx pool config.
 
@@ -284,20 +398,20 @@ func TestBlacklistedTransactions(t *testing.T) {
 	pool.currentState.AddBalance(goodFromAcc, big.NewInt(50100))
 
 	(*DefaultTxPoolConfig.Blacklist)[bannedToAcc] = struct{}{}
-	err := pool.AddRemotes([]*types.Transaction{badTx})
+	err := pool.AddRemotes(types.PoolTransactions{badTx})
 	if err[0] != ErrBlacklistTo {
 		t.Error("expected", ErrBlacklistTo, "got", err[0])
 	}
 
 	delete(*DefaultTxPoolConfig.Blacklist, bannedToAcc)
 	(*DefaultTxPoolConfig.Blacklist)[bannedFromAcc] = struct{}{}
-	err = pool.AddRemotes([]*types.Transaction{badTx})
+	err = pool.AddRemotes(types.PoolTransactions{badTx})
 	if err[0] != ErrBlacklistFrom {
 		t.Error("expected", ErrBlacklistFrom, "got", err[0])
 	}
 
 	// to acc is same for bad and good tx, so keep off blacklist for valid tx check
-	err = pool.AddRemotes([]*types.Transaction{goodTx})
+	err = pool.AddRemotes(types.PoolTransactions{goodTx})
 	if err[0] != nil {
 		t.Error("expected", nil, "got", err[0])
 	}
@@ -346,9 +460,9 @@ func TestTransactionQueue(t *testing.T) {
 	pool.currentState.AddBalance(from, big.NewInt(1000))
 	pool.lockedReset(nil, nil)
 
-	pool.enqueueTx(tx1.Hash(), tx1)
+	pool.enqueueTx(tx.Hash(), tx1)
-	pool.enqueueTx(tx2.Hash(), tx2)
+	pool.enqueueTx(tx.Hash(), tx2)
-	pool.enqueueTx(tx3.Hash(), tx3)
+	pool.enqueueTx(tx.Hash(), tx3)
 
 	pool.promoteExecutables([]common.Address{from})
 
@@ -366,7 +480,9 @@ func TestTransactionNegativeValue(t *testing.T) {
 	pool, key := setupTxPool()
 	defer pool.Stop()
 
-	tx, _ := types.SignTx(types.NewTransaction(0, common.Address{}, 0, big.NewInt(-1), 100, big.NewInt(1), nil), types.HomesteadSigner{}, key)
+	tx, _ := types.SignTx(
+		types.NewTransaction(0, common.Address{}, 0, big.NewInt(-1), 100, big.NewInt(1), nil),
+		types.HomesteadSigner{}, key)
 	from, _ := deriveSender(tx)
 	pool.currentState.AddBalance(from, big.NewInt(1))
 	if err := pool.AddRemote(tx); err != ErrNegativeValue {
@@ -420,9 +536,15 @@ func TestTransactionDoubleNonce(t *testing.T) {
 	resetState()
 
 	signer := types.HomesteadSigner{}
-	tx1, _ := types.SignTx(types.NewTransaction(0, common.Address{}, 0, big.NewInt(100), 100000, big.NewInt(1), nil), signer, key)
+	tx1, _ := types.SignTx(
-	tx2, _ := types.SignTx(types.NewTransaction(0, common.Address{}, 0, big.NewInt(100), 1000000, big.NewInt(2), nil), signer, key)
+		types.NewTransaction(0, common.Address{}, 0, big.NewInt(100), 100000, big.NewInt(1), nil),
-	tx3, _ := types.SignTx(types.NewTransaction(0, common.Address{}, 0, big.NewInt(100), 1000000, big.NewInt(1), nil), signer, key)
+		signer, key)
+	tx2, _ := types.SignTx(
+		types.NewTransaction(0, common.Address{}, 0, big.NewInt(100), 1000000, big.NewInt(2), nil),
+		signer, key)
+	tx3, _ := types.SignTx(
+		types.NewTransaction(0, common.Address{}, 0, big.NewInt(100), 1000000, big.NewInt(1), nil),
+		signer, key)
 
 	// Add the first two transaction, ensure higher priced stays only
 	if replace, err := pool.add(tx1, false); err != nil || replace {
@@ -435,8 +557,8 @@ func TestTransactionDoubleNonce(t *testing.T) {
 	if pool.pending[addr].Len() != 1 {
 		t.Error("expected 1 pending transactions, got", pool.pending[addr].Len())
 	}
-	if tx := pool.pending[addr].txs.items[0]; tx.Hash() != tx2.Hash() {
+	if tx := pool.pending[addr].txs.items[0]; tx.Hash() != (*tx2).Hash() {
-		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), tx2.Hash())
+		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), (*tx2).Hash())
 	}
 	// Add the third transaction and ensure it's not saved (smaller price)
 	pool.add(tx3, false)
@@ -444,8 +566,8 @@ func TestTransactionDoubleNonce(t *testing.T) {
 	if pool.pending[addr].Len() != 1 {
 		t.Error("expected 1 pending transactions, got", pool.pending[addr].Len())
 	}
-	if tx := pool.pending[addr].txs.items[0]; tx.Hash() != tx2.Hash() {
+	if tx := pool.pending[addr].txs.items[0]; tx.Hash() != (*tx2).Hash() {
-		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), tx2.Hash())
+		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), (*tx2).Hash())
 	}
 	// Ensure the total transaction count is correct
 	if pool.all.Count() != 1 {
@@ -604,7 +726,8 @@ func TestTransactionPostponing(t *testing.T) {
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
 	blockchain := &testBlockChain{statedb, 1000000, new(event.Feed)}
 
-	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create two test accounts to produce different gap profiles with
@@ -618,11 +741,11 @@ func TestTransactionPostponing(t *testing.T) {
 		pool.currentState.AddBalance(crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(50100))
 	}
 	// Add a batch consecutive pending transactions for validation
-	txs := []*types.Transaction{}
+	txs := types.PoolTransactions{}
 	for i, key := range keys {
 
 		for j := 0; j < 100; j++ {
-			var tx *types.Transaction
+			var tx types.PoolTransaction
 			if (i+j)%2 == 0 {
 				tx = transaction(uint64(j), 25000, key)
 			} else {
@@ -766,7 +889,8 @@ func testTransactionQueueGlobalLimiting(t *testing.T, nolocals bool) {
 	config.NoLocals = nolocals
 	config.GlobalQueue = config.AccountQueue*3 - 1 // reduce the queue limits to shorten test time (-1 to make it non divisible)
 
-	pool := NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create a number of test accounts and fund them (last one will be the local)
@@ -780,7 +904,7 @@ func testTransactionQueueGlobalLimiting(t *testing.T, nolocals bool) {
 	// Generate and queue a batch of transactions
 	nonces := make(map[common.Address]uint64)
 
-	txs := make(types.Transactions, 0, 3*config.GlobalQueue)
+	txs := make(types.PoolTransactions, 0, 3*config.GlobalQueue)
 	for len(txs) < cap(txs) {
 		key := keys[rand.Intn(len(keys)-1)] // skip adding transactions with the local account
 		addr := crypto.PubkeyToAddress(key.PublicKey)
@@ -854,7 +978,8 @@ func testTransactionQueueTimeLimiting(t *testing.T, nolocals bool) {
 	config.Lifetime = time.Second
 	config.NoLocals = nolocals
 
-	pool := NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create two test accounts to ensure remotes expire but locals do not
@@ -929,7 +1054,7 @@ func testTransactionLimitingEquivalency(t *testing.T, origin uint64) {
 	account2, _ := deriveSender(transaction(0, 0, key2))
 	pool2.currentState.AddBalance(account2, big.NewInt(1000000))
 
-	txs := []*types.Transaction{}
+	txs := types.PoolTransactions{}
 	for i := uint64(0); i < testTxPoolConfig.AccountQueue+5; i++ {
 		txs = append(txs, transaction(origin+i, 100000, key2))
 	}
@@ -966,7 +1091,8 @@ func TestTransactionPendingGlobalLimiting(t *testing.T) {
 	config := testTxPoolConfig
 	config.GlobalSlots = config.AccountSlots * 10
 
-	pool := NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create a number of test accounts and fund them
@@ -978,7 +1104,7 @@ func TestTransactionPendingGlobalLimiting(t *testing.T) {
 	// Generate and queue a batch of transactions
 	nonces := make(map[common.Address]uint64)
 
-	txs := types.Transactions{}
+	txs := types.PoolTransactions{}
 	for _, key := range keys {
 		addr := crypto.PubkeyToAddress(key.PublicKey)
 		for j := 0; j < int(config.GlobalSlots)/len(keys)*2; j++ {
@@ -1014,7 +1140,8 @@ func TestTransactionCapClearsFromAll(t *testing.T) {
 	config.AccountQueue = 2
 	config.GlobalSlots = 8
 
-	pool := NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create a number of test accounts and fund them
@@ -1022,7 +1149,7 @@ func TestTransactionCapClearsFromAll(t *testing.T) {
 	addr := crypto.PubkeyToAddress(key.PublicKey)
 	pool.currentState.AddBalance(addr, big.NewInt(1000000))
 
-	txs := types.Transactions{}
+	txs := types.PoolTransactions{}
 	for j := 0; j < int(config.GlobalSlots)*2; j++ {
 		txs = append(txs, transaction(uint64(j), 100000, key))
 	}
@@ -1046,7 +1173,8 @@ func TestTransactionPendingMinimumAllowance(t *testing.T) {
 	config := testTxPoolConfig
 	config.GlobalSlots = 0
 
-	pool := NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create a number of test accounts and fund them
@@ -1058,7 +1186,7 @@ func TestTransactionPendingMinimumAllowance(t *testing.T) {
 	// Generate and queue a batch of transactions
 	nonces := make(map[common.Address]uint64)
 
-	txs := types.Transactions{}
+	txs := types.PoolTransactions{}
 	for _, key := range keys {
 		addr := crypto.PubkeyToAddress(key.PublicKey)
 		for j := 0; j < int(config.AccountSlots)*2; j++ {
@@ -1088,7 +1216,8 @@ func TestTransactionPoolRepricingKeepsLocals(t *testing.T) {
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
 	blockchain := &testBlockChain{statedb, 1000000, new(event.Feed)}
 
-	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create a number of test accounts and fund them
@@ -1167,7 +1296,8 @@ func testTransactionJournaling(t *testing.T, nolocals bool) {
 	config.Journal = journal
 	config.Rejournal = time.Second
 
-	pool := NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 
 	// Create two test accounts to ensure remotes expire but locals do not
 	local, _ := crypto.GenerateKey()
@@ -1204,7 +1334,8 @@ func testTransactionJournaling(t *testing.T, nolocals bool) {
 	statedb.SetNonce(crypto.PubkeyToAddress(local.PublicKey), 1)
 	blockchain = &testBlockChain{statedb, 1000000, new(event.Feed)}
 
-	pool = NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool = NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 
 	pending, queued = pool.Stats()
 	if queued != 0 {
@@ -1230,7 +1361,8 @@ func testTransactionJournaling(t *testing.T, nolocals bool) {
 
 	statedb.SetNonce(crypto.PubkeyToAddress(local.PublicKey), 1)
 	blockchain = &testBlockChain{statedb, 1000000, new(event.Feed)}
-	pool = NewTxPool(config, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool = NewTxPool(config, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 
 	pending, queued = pool.Stats()
 	if pending != 0 {
@@ -1260,7 +1392,8 @@ func TestTransactionStatusCheck(t *testing.T) {
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(ethdb.NewMemDatabase()))
 	blockchain := &testBlockChain{statedb, 1000000, new(event.Feed)}
 
-	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain, func([]types.RPCTransactionError) {})
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, blockchain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 	defer pool.Stop()
 
 	// Create the test accounts to check various transaction statuses with
@@ -1270,7 +1403,7 @@ func TestTransactionStatusCheck(t *testing.T) {
 		pool.currentState.AddBalance(crypto.PubkeyToAddress(keys[i].PublicKey), big.NewInt(1000000))
 	}
 	// Generate and queue a batch of transactions, both pending and queued
-	txs := types.Transactions{}
+	txs := types.PoolTransactions{}
 
 	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[0])) // Pending only
 	txs = append(txs, pricedTransaction(0, 100000, big.NewInt(1), keys[1])) // Pending and queued
@@ -1366,7 +1499,7 @@ func BenchmarkPoolInsert(b *testing.B) {
 	account, _ := deriveSender(transaction(0, 0, key))
 	pool.currentState.AddBalance(account, big.NewInt(1000000))
 
-	txs := make(types.Transactions, b.N)
+	txs := make(types.PoolTransactions, b.N)
 	for i := 0; i < b.N; i++ {
 		txs[i] = transaction(uint64(i), 100000, key)
 	}
@@ -1390,9 +1523,9 @@ func benchmarkPoolBatchInsert(b *testing.B, size int) {
 	account, _ := deriveSender(transaction(0, 0, key))
 	pool.currentState.AddBalance(account, big.NewInt(1000000))
 
-	batches := make([]types.Transactions, b.N)
+	batches := make([]types.PoolTransactions, b.N)
 	for i := 0; i < b.N; i++ {
-		batches[i] = make(types.Transactions, size)
+		batches[i] = make(types.PoolTransactions, size)
 		for j := 0; j < size; j++ {
 			batches[i][j] = transaction(uint64(size*i+j), 100000, key)
 		}

core/types/transaction.go

@@ -79,8 +79,8 @@ type RPCTransactionError struct {
 }
 
 // NewRPCTransactionError ...
-func NewRPCTransactionError(hash common.Hash, err error) *RPCTransactionError {
+func NewRPCTransactionError(hash common.Hash, err error) RPCTransactionError {
-	return &RPCTransactionError{
+	return RPCTransactionError{
 		TxHashID:             hash.Hex(),
 		TimestampOfRejection: time.Now().Unix(),
 		ErrMessage:           err.Error(),

core/types/tx_pool.go

@@ -0,0 +1,96 @@
+package types
+
+import (
+	"io"
+	"math/big"
+
+	"github.com/pkg/errors"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/rlp"
+	staking "github.com/harmony-one/harmony/staking/types"
+)
+
+var (
+	// ErrUnknownPoolTxType is returned when attempting to assert a PoolTransaction to its concrete type
+	ErrUnknownPoolTxType = errors.New("unknown transaction type in tx-pool")
+)
+
+// PoolTransaction is the general transaction interface used by the tx pool
+type PoolTransaction interface {
+	Hash() common.Hash
+	Nonce() uint64
+	ChainID() *big.Int
+	To() *common.Address
+	Size() common.StorageSize
+	Data() []byte
+	GasPrice() *big.Int
+	Gas() uint64
+	Cost() *big.Int
+	Value() *big.Int
+	EncodeRLP(w io.Writer) error
+	DecodeRLP(s *rlp.Stream) error
+	Protected() bool
+}
+
+// PoolTransactionSender returns the address derived from the signature (V, R, S) u
+// sing secp256k1 elliptic curve and an error if it failed deriving or upon an
+// incorrect signature.
+//
+// Sender may cache the address, allowing it to be used regardless of
+// signing method. The cache is invalidated if the cached signer does
+// not match the signer used in the current call.
+//
+// Note that the signer is an interface since different txs have different signers.
+func PoolTransactionSender(signer interface{}, tx PoolTransaction) (common.Address, error) {
+	if plainTx, ok := tx.(*Transaction); ok {
+		if sig, ok := signer.(Signer); ok {
+			return Sender(sig, plainTx)
+		}
+	} else if stakingTx, ok := tx.(*staking.StakingTransaction); ok {
+		return stakingTx.SenderAddress()
+	}
+	return common.Address{}, errors.WithMessage(ErrUnknownPoolTxType, "when fetching transaction sender")
+}
+
+// PoolTransactions is a PoolTransactions slice type for basic sorting.
+type PoolTransactions []PoolTransaction
+
+// Len returns the length of s.
+func (s PoolTransactions) Len() int { return len(s) }
+
+// Swap swaps the i'th and the j'th element in s.
+func (s PoolTransactions) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+
+// GetRlp implements Rlpable and returns the i'th element of s in rlp.
+func (s PoolTransactions) GetRlp(i int) []byte {
+	enc, _ := rlp.EncodeToBytes(s[i])
+	return enc
+}
+
+// PoolTxDifference returns a new set which is the difference between a and b.
+func PoolTxDifference(a, b PoolTransactions) PoolTransactions {
+	keep := make(PoolTransactions, 0, len(a))
+
+	remove := make(map[common.Hash]struct{})
+	for _, tx := range b {
+		remove[tx.Hash()] = struct{}{}
+	}
+
+	for _, tx := range a {
+		if _, ok := remove[tx.Hash()]; !ok {
+			keep = append(keep, tx)
+		}
+	}
+
+	return keep
+}
+
+// PoolTxByNonce implements the sort interface to allow sorting a list of transactions
+// by their nonces. This is usually only useful for sorting transactions from a
+// single account, otherwise a nonce comparison doesn't make much sense.
+type PoolTxByNonce PoolTransactions
+
+func (s PoolTxByNonce) Len() int           { return len(s) }
+func (s PoolTxByNonce) Less(i, j int) bool { return (s[i]).Nonce() < (s[j]).Nonce() }
+func (s PoolTxByNonce) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }

hmy/api_backend.go

@@ -48,7 +48,7 @@ func (b *APIBackend) GetBlock(ctx context.Context, hash common.Hash) (*types.Blo
 }
 
 // GetPoolTransaction ...
-func (b *APIBackend) GetPoolTransaction(hash common.Hash) *types.Transaction {
+func (b *APIBackend) GetPoolTransaction(hash common.Hash) types.PoolTransaction {
 	return b.hmy.txPool.Get(hash)
 }
 
@@ -208,12 +208,12 @@ func (b *APIBackend) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscripti
 
 // GetPoolTransactions returns pool transactions.
 // TODO: this is not implemented or verified yet for harmony.
-func (b *APIBackend) GetPoolTransactions() (types.Transactions, error) {
+func (b *APIBackend) GetPoolTransactions() (types.PoolTransactions, error) {
 	pending, err := b.hmy.txPool.Pending()
 	if err != nil {
 		return nil, err
 	}
-	var txs types.Transactions
+	var txs types.PoolTransactions
 	for _, batch := range pending {
 		txs = append(txs, batch...)
 	}

internal/hmyapi/apiv1/backend.go

@@ -52,8 +52,8 @@ type Backend interface {
 	// TxPool API
 	SendTx(ctx context.Context, signedTx *types.Transaction) error
 	// GetTransaction(ctx context.Context, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error)
-	GetPoolTransactions() (types.Transactions, error)
+	GetPoolTransactions() (types.PoolTransactions, error)
-	GetPoolTransaction(txHash common.Hash) *types.Transaction
+	GetPoolTransaction(txHash common.Hash) types.PoolTransaction
 	GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error)
 	// Stats() (pending int, queued int)
 	// TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)

internal/hmyapi/apiv1/transactionpool.go

@@ -106,7 +106,7 @@ func (s *PublicTransactionPoolAPI) GetTransactionByBlockHashAndIndex(ctx context
 	return nil
 }
 
-// GetTransactionByHash returns the transaction for the given hash
+// GetTransactionByHash returns the plain transaction for the given hash
 func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, hash common.Hash) *RPCTransaction {
 	// Try to return an already finalized transaction
 	tx, blockHash, blockNumber, index := rawdb.ReadTransaction(s.b.ChainDb(), hash)
@@ -117,15 +117,11 @@ func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, has
 	if tx != nil {
 		return newRPCTransaction(tx, blockHash, blockNumber, block.Time().Uint64(), index)
 	}
-	// No finalized transaction, try to retrieve it from the pool
-	if tx = s.b.GetPoolTransaction(hash); tx != nil {
-		return newRPCPendingTransaction(tx)
-	}
 	// Transaction unknown, return as such
 	return nil
 }
 
-// GetStakingTransactionByHash returns the transaction for the given hash
+// GetStakingTransactionByHash returns the staking transaction for the given hash
 func (s *PublicTransactionPoolAPI) GetStakingTransactionByHash(ctx context.Context, hash common.Hash) *RPCStakingTransaction {
 	// Try to return an already finalized transaction
 	stx, blockHash, blockNumber, index := rawdb.ReadStakingTransaction(s.b.ChainDb(), hash)
@@ -136,6 +132,7 @@ func (s *PublicTransactionPoolAPI) GetStakingTransactionByHash(ctx context.Conte
 	if stx != nil {
 		return newRPCStakingTransaction(stx, blockHash, blockNumber, block.Time().Uint64(), index)
 	}
+	// Transaction unknown, return as such
 	return nil
 }
 
@@ -332,7 +329,7 @@ func (s *PublicTransactionPoolAPI) GetTransactionReceipt(ctx context.Context, ha
 	return fields, nil
 }
 
-// PendingTransactions returns the transactions that are in the transaction pool
+// PendingTransactions returns the plain transactions that are in the transaction pool
 func (s *PublicTransactionPoolAPI) PendingTransactions() ([]*RPCTransaction, error) {
 	pending, err := s.b.GetPoolTransactions()
 	if err != nil {
@@ -340,7 +337,32 @@ func (s *PublicTransactionPoolAPI) PendingTransactions() ([]*RPCTransaction, err
 	}
 	transactions := make([]*RPCTransaction, len(pending))
 	for i := range pending {
-		transactions[i] = newRPCPendingTransaction(pending[i])
+		if plainTx, ok := pending[i].(*types.Transaction); ok {
+			transactions[i] = newRPCPendingTransaction(plainTx)
+		} else if _, ok := pending[i].(*staking.StakingTransaction); ok {
+			continue // Do not return staking transactions here.
+		} else {
+			return nil, types.ErrUnknownPoolTxType
+		}
+	}
+	return transactions, nil
+}
+
+// PendingStakingTransactions returns the staking transactions that are in the transaction pool
+func (s *PublicTransactionPoolAPI) PendingStakingTransactions() ([]*RPCStakingTransaction, error) {
+	pending, err := s.b.GetPoolTransactions()
+	if err != nil {
+		return nil, err
+	}
+	transactions := make([]*RPCStakingTransaction, len(pending))
+	for i := range pending {
+		if _, ok := pending[i].(*types.Transaction); ok {
+			continue // Do not return plain transactions here
+		} else if stakingTx, ok := pending[i].(*staking.StakingTransaction); ok {
+			transactions[i] = newRPCPendingStakingTransaction(stakingTx)
+		} else {
+			return nil, types.ErrUnknownPoolTxType
+		}
 	}
 	return transactions, nil
 }

internal/hmyapi/apiv1/types.go

@@ -296,7 +296,7 @@ func newRPCStakingTransaction(tx *types2.StakingTransaction, blockHash common.Ha
 
 	result := &RPCStakingTransaction{
 		Gas:       hexutil.Uint64(tx.Gas()),
-		GasPrice:  (*hexutil.Big)(tx.Price()),
+		GasPrice:  (*hexutil.Big)(tx.GasPrice()),
 		Hash:      tx.Hash(),
 		Nonce:     hexutil.Uint64(tx.Nonce()),
 		Timestamp: hexutil.Uint64(timestamp),
@@ -326,6 +326,11 @@ func newRPCPendingTransaction(tx *types.Transaction) *RPCTransaction {
 	return newRPCTransaction(tx, common.Hash{}, 0, 0, 0)
 }
 
+// newRPCPendingStakingTransaction returns a pending transaction that will serialize to the RPC representation
+func newRPCPendingStakingTransaction(tx *types2.StakingTransaction) *RPCStakingTransaction {
+	return newRPCStakingTransaction(tx, common.Hash{}, 0, 0, 0)
+}
+
 // RPCBlock represents a block that will serialize to the RPC representation of a block
 type RPCBlock struct {
 	Number           *hexutil.Big     `json:"number"`

internal/hmyapi/apiv2/backend.go

@@ -52,8 +52,8 @@ type Backend interface {
 	// TxPool API
 	SendTx(ctx context.Context, signedTx *types.Transaction) error
 	// GetTransaction(ctx context.Context, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error)
-	GetPoolTransactions() (types.Transactions, error)
+	GetPoolTransactions() (types.PoolTransactions, error)
-	GetPoolTransaction(txHash common.Hash) *types.Transaction
+	GetPoolTransaction(txHash common.Hash) types.PoolTransaction
 	GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error)
 	// Stats() (pending int, queued int)
 	// TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)

internal/hmyapi/apiv2/transactionpool.go

@@ -115,10 +115,6 @@ func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, has
 	if tx != nil {
 		return newRPCTransaction(tx, blockHash, blockNumber, block.Time().Uint64(), index)
 	}
-	// No finalized transaction, try to retrieve it from the pool
-	if tx = s.b.GetPoolTransaction(hash); tx != nil {
-		return newRPCPendingTransaction(tx)
-	}
 	// Transaction unknown, return as such
 	return nil
 }
@@ -134,6 +130,7 @@ func (s *PublicTransactionPoolAPI) GetStakingTransactionByHash(ctx context.Conte
 	if stx != nil {
 		return newRPCStakingTransaction(stx, blockHash, blockNumber, block.Time().Uint64(), index)
 	}
+	// Transaction unknown, return as such
 	return nil
 }
 
@@ -330,17 +327,17 @@ func (s *PublicTransactionPoolAPI) GetTransactionReceipt(ctx context.Context, ha
 	return fields, nil
 }
 
-// PendingTransactions returns the transactions that are in the transaction pool
+// PendingTransactions returns the plain transactions that are in the transaction pool
 // and have a from address that is one of the accounts this node manages.
 func (s *PublicTransactionPoolAPI) PendingTransactions() ([]*RPCTransaction, error) {
 	pending, err := s.b.GetPoolTransactions()
 	if err != nil {
 		return nil, err
 	}
-	accounts := make(map[common.Address]struct{})
+	managedAccounts := make(map[common.Address]struct{})
 	for _, wallet := range s.b.AccountManager().Wallets() {
 		for _, account := range wallet.Accounts() {
-			accounts[account.Address] = struct{}{}
+			managedAccounts[account.Address] = struct{}{}
 		}
 	}
 	transactions := make([]*RPCTransaction, 0, len(pending))
@@ -349,9 +346,48 @@ func (s *PublicTransactionPoolAPI) PendingTransactions() ([]*RPCTransaction, err
 		if tx.Protected() {
 			signer = types.NewEIP155Signer(tx.ChainID())
 		}
-		from, _ := types.Sender(signer, tx)
+		from, _ := types.PoolTransactionSender(signer, tx)
-		if _, exists := accounts[from]; exists {
+		if _, exists := managedAccounts[from]; exists {
-			transactions = append(transactions, newRPCPendingTransaction(tx))
+			if plainTx, ok := tx.(*types.Transaction); ok {
+				transactions = append(transactions, newRPCPendingTransaction(plainTx))
+			} else if _, ok := tx.(*staking.StakingTransaction); ok {
+				continue // Do not return staking transactions here
+			} else {
+				return nil, types.ErrUnknownPoolTxType
+			}
+		}
+	}
+	return transactions, nil
+}
+
+// PendingStakingTransactions returns the staking transactions that are in the transaction pool
+// and have a from address that is one of the accounts this node manages.
+func (s *PublicTransactionPoolAPI) PendingStakingTransactions() ([]*RPCStakingTransaction, error) {
+	pending, err := s.b.GetPoolTransactions()
+	if err != nil {
+		return nil, err
+	}
+	managedAccounts := make(map[common.Address]struct{})
+	for _, wallet := range s.b.AccountManager().Wallets() {
+		for _, account := range wallet.Accounts() {
+			managedAccounts[account.Address] = struct{}{}
+		}
+	}
+	transactions := make([]*RPCStakingTransaction, 0, len(pending))
+	for _, tx := range pending {
+		var signer types.Signer = types.HomesteadSigner{}
+		if tx.Protected() {
+			signer = types.NewEIP155Signer(tx.ChainID())
+		}
+		from, _ := types.PoolTransactionSender(signer, tx)
+		if _, exists := managedAccounts[from]; exists {
+			if _, ok := tx.(*types.Transaction); ok {
+				continue // Do not return plain transactions here
+			} else if stakingTx, ok := tx.(*staking.StakingTransaction); ok {
+				transactions = append(transactions, newRPCPendingStakingTransaction(stakingTx))
+			} else {
+				return nil, types.ErrUnknownPoolTxType
+			}
 		}
 	}
 	return transactions, nil

internal/hmyapi/apiv2/types.go

@@ -297,7 +297,7 @@ func newRPCStakingTransaction(tx *types2.StakingTransaction, blockHash common.Ha
 
 	result := &RPCStakingTransaction{
 		Gas:       tx.Gas(),
-		GasPrice:  tx.Price(),
+		GasPrice:  tx.GasPrice(),
 		Hash:      tx.Hash(),
 		Nonce:     tx.Nonce(),
 		Timestamp: timestamp,
@@ -327,6 +327,11 @@ func newRPCPendingTransaction(tx *types.Transaction) *RPCTransaction {
 	return newRPCTransaction(tx, common.Hash{}, 0, 0, 0)
 }
 
+// newRPCPendingStakingTransaction returns a pending transaction that will serialize to the RPC representation
+func newRPCPendingStakingTransaction(tx *types2.StakingTransaction) *RPCStakingTransaction {
+	return newRPCStakingTransaction(tx, common.Hash{}, 0, 0, 0)
+}
+
 // RPCBlock represents a block that will serialize to the RPC representation of a block
 type RPCBlock struct {
 	Number           *big.Int         `json:"number"`

internal/hmyapi/backend.go

@@ -54,8 +54,8 @@ type Backend interface {
 	// TxPool API
 	SendTx(ctx context.Context, signedTx *types.Transaction) error
 	// GetTransaction(ctx context.Context, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error)
-	GetPoolTransactions() (types.Transactions, error)
+	GetPoolTransactions() (types.PoolTransactions, error)
-	GetPoolTransaction(txHash common.Hash) *types.Transaction
+	GetPoolTransaction(txHash common.Hash) types.PoolTransaction
 	GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error)
 	// Stats() (pending int, queued int)
 	// TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)

node/node.go

@@ -134,9 +134,6 @@ type Node struct {
 
 	CxPool *core.CxPool // pool for missing cross shard receipts resend
 
-	pendingStakingTransactions map[common.Hash]*staking.StakingTransaction // All the staking transactions received but not yet processed for Consensus
-	pendingStakingTxMutex      sync.Mutex
-
 	Worker       *worker.Worker
 	BeaconWorker *worker.Worker // worker for beacon chain
 
@@ -282,50 +279,45 @@ func (node *Node) tryBroadcastStaking(stakingTx *staking.StakingTransaction) {
 
 // Add new transactions to the pending transaction list.
 func (node *Node) addPendingTransactions(newTxs types.Transactions) {
-	node.TxPool.AddRemotes(newTxs)
+	poolTxs := types.PoolTransactions{}
+	for _, tx := range newTxs {
+		poolTxs = append(poolTxs, tx)
+	}
+	node.TxPool.AddRemotes(poolTxs)
 
 	pendingCount, queueCount := node.TxPool.Stats()
-	utils.Logger().Info().Int("length of newTxs", len(newTxs)).Int("totalPending", pendingCount).Int("totalQueued", queueCount).Msg("Got more transactions")
+	utils.Logger().Info().
+		Int("length of newTxs", len(newTxs)).
+		Int("totalPending", pendingCount).
+		Int("totalQueued", queueCount).
+		Msg("Got more transactions")
 }
 
 // Add new staking transactions to the pending staking transaction list.
 func (node *Node) addPendingStakingTransactions(newStakingTxs staking.StakingTransactions) {
-	// TODO: incorporate staking txn into TxPool
 	if node.NodeConfig.ShardID == shard.BeaconChainShardID &&
 		node.Blockchain().Config().IsPreStaking(node.Blockchain().CurrentHeader().Epoch()) {
-		node.pendingStakingTxMutex.Lock()
+		poolTxs := types.PoolTransactions{}
 		for _, tx := range newStakingTxs {
-			const txPoolLimit = 1000
+			poolTxs = append(poolTxs, tx)
-			if s := len(node.pendingStakingTransactions); s >= txPoolLimit {
-				utils.Logger().Info().
-					Int("tx-pool-size", s).
-					Int("tx-pool-limit", txPoolLimit).
-					Msg("Current staking txn pool reached limit")
-				break
-			}
-			if _, ok := node.pendingStakingTransactions[tx.Hash()]; !ok {
-				node.pendingStakingTransactions[tx.Hash()] = tx
-			}
 		}
+		node.TxPool.AddRemotes(poolTxs)
+		pendingCount, queueCount := node.TxPool.Stats()
 		utils.Logger().Info().
-			Int("length of newStakingTxs", len(newStakingTxs)).
+			Int("length of newStakingTxs", len(poolTxs)).
-			Int("totalPending", len(node.pendingStakingTransactions)).
+			Int("totalPending", pendingCount).
+			Int("totalQueued", queueCount).
 			Msg("Got more staking transactions")
-		node.pendingStakingTxMutex.Unlock()
 	}
 }
 
 // AddPendingStakingTransaction staking transactions
-func (node *Node) AddPendingStakingTransaction(
+func (node *Node) AddPendingStakingTransaction(newStakingTx *staking.StakingTransaction) {
-	newStakingTx *staking.StakingTransaction) {
+	if node.NodeConfig.ShardID == shard.BeaconChainShardID {
-	// TODO: everyone should record staking txns, not just leader
-	if node.Consensus.IsLeader() &&
-		node.NodeConfig.ShardID == shard.BeaconChainShardID {
 		node.addPendingStakingTransactions(staking.StakingTransactions{newStakingTx})
-	} else {
+	}
 	utils.Logger().Info().Str("Hash", newStakingTx.Hash().Hex()).Msg("Broadcasting Staking Tx")
 	node.tryBroadcastStaking(newStakingTx)
-	}
 }
 
 // AddPendingTransaction adds one new transaction to the pending transaction list.
@@ -333,9 +325,6 @@ func (node *Node) AddPendingStakingTransaction(
 func (node *Node) AddPendingTransaction(newTx *types.Transaction) {
 	if newTx.ShardID() == node.NodeConfig.ShardID {
 		node.addPendingTransactions(types.Transactions{newTx})
-		if node.NodeConfig.Role() != nodeconfig.ExplorerNode {
-			return
-		}
 	}
 	utils.Logger().Info().Str("Hash", newTx.Hash().Hex()).Msg("Broadcasting Tx")
 	node.tryBroadcast(newTx)
@@ -515,7 +504,16 @@ func New(host p2p.Host, consensusObj *consensus.Consensus,
 					}
 					node.errorSink.Unlock()
 				}
-			})
+			},
+			func(payload []staking.RPCTransactionError) {
+				node.errorSink.Lock()
+				for i := range payload {
+					node.errorSink.failedStakingTxns.Value = payload[i]
+					node.errorSink.failedStakingTxns = node.errorSink.failedStakingTxns.Next()
+				}
+				node.errorSink.Unlock()
+			},
+		)
 		node.CxPool = core.NewCxPool(core.CxPoolSize)
 		node.Worker = worker.New(node.Blockchain().Config(), blockchain, chain.Engine)
 
@@ -526,7 +524,6 @@ func New(host p2p.Host, consensusObj *consensus.Consensus,
 		}
 
 		node.pendingCXReceipts = make(map[string]*types.CXReceiptsProof)
-		node.pendingStakingTransactions = make(map[common.Hash]*staking.StakingTransaction)
 		node.Consensus.VerifiedNewBlock = make(chan *types.Block)
 		chain.Engine.SetRewarder(node.Consensus.Decider.(reward.Distributor))
 		chain.Engine.SetBeaconchain(beaconChain)

node/node_handler_test.go

@@ -39,7 +39,6 @@ func TestAddNewBlock(t *testing.T) {
 	stks := staking.StakingTransactions{}
 	node.Worker.CommitTransactions(
 		txs, stks, common.Address{},
-		func([]staking.RPCTransactionError) {},
 	)
 	block, _ := node.Worker.FinalizeNewBlock(
 		[]byte{}, []byte{}, 0, common.Address{}, nil, nil, nil,
@@ -77,7 +76,6 @@ func TestVerifyNewBlock(t *testing.T) {
 	stks := staking.StakingTransactions{}
 	node.Worker.CommitTransactions(
 		txs, stks, common.Address{},
-		func([]staking.RPCTransactionError) {},
 	)
 	block, _ := node.Worker.FinalizeNewBlock(
 		[]byte{}, []byte{}, 0, common.Address{}, nil, nil, nil,

node/node_newblock.go

@@ -103,34 +103,35 @@ func (node *Node) proposeNewBlock() (*types.Block, error) {
 	}
 
 	// Prepare transactions including staking transactions
-	pending, err := node.TxPool.Pending()
+	pendingPoolTxs, err := node.TxPool.Pending()
 	if err != nil {
 		utils.Logger().Err(err).Msg("Failed to fetch pending transactions")
 		return nil, err
 	}
-
+	pendingPlainTxs := map[common.Address]types.Transactions{}
-	// TODO: integrate staking transaction into tx pool
+	pendingStakingTxs := staking.StakingTransactions{}
-	pendingStakingTransactions := staking.StakingTransactions{}
+	for addr, poolTxs := range pendingPoolTxs {
+		plainTxsPerAcc := types.Transactions{}
+		for _, tx := range poolTxs {
+			if plainTx, ok := tx.(*types.Transaction); ok {
+				plainTxsPerAcc = append(plainTxsPerAcc, plainTx)
+			} else if stakingTx, ok := tx.(*staking.StakingTransaction); ok {
 				// Only process staking transactions after pre-staking epoch happened.
 				if node.Blockchain().Config().IsPreStaking(node.Worker.GetCurrentHeader().Epoch()) {
-		node.pendingStakingTxMutex.Lock()
+					pendingStakingTxs = append(pendingStakingTxs, stakingTx)
-		for _, tx := range node.pendingStakingTransactions {
+				}
-			pendingStakingTransactions = append(pendingStakingTransactions, tx)
+			} else {
+				utils.Logger().Err(types.ErrUnknownPoolTxType).Msg("Failed to parse pending transactions")
+				return nil, types.ErrUnknownPoolTxType
+			}
+		}
+		if plainTxsPerAcc.Len() > 0 {
+			pendingPlainTxs[addr] = plainTxsPerAcc
 		}
-		node.pendingStakingTransactions = make(map[common.Hash]*staking.StakingTransaction)
-		node.pendingStakingTxMutex.Unlock()
 	}
 
 	if err := node.Worker.CommitTransactions(
-		pending, pendingStakingTransactions, beneficiary,
+		pendingPlainTxs, pendingStakingTxs, beneficiary,
-		func(payload []staking.RPCTransactionError) {
-			node.errorSink.Lock()
-			for i := range payload {
-				node.errorSink.failedStakingTxns.Value = payload[i]
-				node.errorSink.failedStakingTxns = node.errorSink.failedStakingTxns.Next()
-			}
-			node.errorSink.Unlock()
-		},
 	); err != nil {
 		utils.Logger().Error().Err(err).Msg("cannot commit transactions")
 		return nil, err

node/worker/worker.go

@@ -55,7 +55,6 @@ type Worker struct {
 func (w *Worker) CommitTransactions(
 	pendingNormal map[common.Address]types.Transactions,
 	pendingStaking staking.StakingTransactions, coinbase common.Address,
-	stkingTxErrorSink func([]staking.RPCTransactionError),
 ) error {
 
 	if w.current.gasPool == nil {
@@ -64,7 +63,6 @@ func (w *Worker) CommitTransactions(
 
 	txs := types.NewTransactionsByPriceAndNonce(w.current.signer, pendingNormal)
 	coalescedLogs := []*types.Log{}
-	erroredStakingTxns := []staking.RPCTransactionError{}
 	// NORMAL
 	for {
 		// If we don't have enough gas for any further transactions then we're done
@@ -134,12 +132,6 @@ func (w *Worker) CommitTransactions(
 			logs, err := w.commitStakingTransaction(tx, coinbase)
 			if err != nil {
 				txID := tx.Hash().Hex()
-				erroredStakingTxns = append(erroredStakingTxns, staking.RPCTransactionError{
-					TxHashID:             txID,
-					StakingDirective:     tx.StakingType().String(),
-					TimestampOfRejection: time.Now().Unix(),
-					ErrMessage:           err.Error(),
-				})
 				utils.Logger().Error().Err(err).
 					Str("stakingTxId", txID).
 					Msg("Commit staking transaction error")
@@ -151,8 +143,6 @@ func (w *Worker) CommitTransactions(
 			}
 		}
 	}
-	// Here call the error functions
-	stkingTxErrorSink(erroredStakingTxns)
 
 	utils.Logger().Info().
 		Int("newTxns", len(w.current.txs)).

node/worker/worker_test.go

@@ -15,7 +15,6 @@ import (
 	"github.com/harmony-one/harmony/core/vm"
 	chain2 "github.com/harmony-one/harmony/internal/chain"
 	"github.com/harmony-one/harmony/internal/params"
-	staking "github.com/harmony-one/harmony/staking/types"
 )
 
 var (
@@ -80,7 +79,6 @@ func TestCommitTransactions(t *testing.T) {
 	txs[testBankAddress] = types.Transactions{tx}
 	err := worker.CommitTransactions(
 		txs, nil, testBankAddress,
-		func([]staking.RPCTransactionError) {},
 	)
 	if err != nil {
 		t.Error(err)

staking/types/rpc-result.go

@@ -1,9 +0,0 @@
-package types
-
-// RPCTransactionError ..
-type RPCTransactionError struct {
-	TxHashID             string `json:"tx-hash-id"`
-	StakingDirective     string `json:"directive-kind"`
-	TimestampOfRejection int64  `json:"time-at-rejection"`
-	ErrMessage           string `json:"error-message"`
-}

staking/types/transaction.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"math/big"
 	"sync/atomic"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/rlp"
@@ -72,6 +73,24 @@ type StakingTransaction struct {
 	from atomic.Value
 }
 
+// RPCTransactionError ..
+type RPCTransactionError struct {
+	TxHashID             string `json:"tx-hash-id"`
+	StakingDirective     string `json:"directive-kind"`
+	TimestampOfRejection int64  `json:"time-at-rejection"`
+	ErrMessage           string `json:"error-message"`
+}
+
+// NewRPCTransactionError ...
+func NewRPCTransactionError(hash common.Hash, directive Directive, err error) RPCTransactionError {
+	return RPCTransactionError{
+		TxHashID:             hash.Hex(),
+		StakingDirective:     directive.String(),
+		TimestampOfRejection: time.Now().Unix(),
+		ErrMessage:           err.Error(),
+	}
+}
+
 // StakeMsgFulfiller is signature of callback intended to produce the StakeMsg
 type StakeMsgFulfiller func() (Directive, interface{})
 
@@ -146,11 +165,16 @@ func (tx *StakingTransaction) Gas() uint64 {
 	return tx.data.GasLimit
 }
 
-// Price returns price of StakingTransaction.
+// GasPrice returns price of StakingTransaction.
-func (tx *StakingTransaction) Price() *big.Int {
+func (tx *StakingTransaction) GasPrice() *big.Int {
 	return tx.data.Price
 }
 
+// Cost ..
+func (tx *StakingTransaction) Cost() *big.Int {
+	return new(big.Int).Mul(tx.data.Price, new(big.Int).SetUint64(tx.data.GasLimit))
+}
+
 // ChainID is what chain this staking transaction for
 func (tx *StakingTransaction) ChainID() *big.Int {
 	return deriveChainID(tx.data.V)
@@ -184,6 +208,48 @@ func (tx *StakingTransaction) RLPEncodeStakeMsg() (by []byte, err error) {
 	return rlp.EncodeToBytes(tx.data.StakeMsg)
 }
 
+// Protected ..
+func (tx *StakingTransaction) Protected() bool {
+	return true
+}
+
+// To ..
+func (tx *StakingTransaction) To() *common.Address {
+	return nil
+}
+
+// Data ..
+func (tx *StakingTransaction) Data() []byte {
+	data, err := tx.RLPEncodeStakeMsg()
+	if err != nil {
+		return nil
+	}
+	return data
+}
+
+// Value ..
+func (tx *StakingTransaction) Value() *big.Int {
+	return new(big.Int).SetInt64(0)
+}
+
+// Size ..
+func (tx *StakingTransaction) Size() common.StorageSize {
+	if size := tx.size.Load(); size != nil {
+		return size.(common.StorageSize)
+	}
+	c := writeCounter(0)
+	rlp.Encode(&c, &tx.data)
+	tx.size.Store(common.StorageSize(c))
+	return common.StorageSize(c)
+}
+
+type writeCounter common.StorageSize
+
+func (c *writeCounter) Write(b []byte) (int, error) {
+	*c += writeCounter(len(b))
+	return len(b), nil
+}
+
 // RLPDecodeStakeMsg ..
 func RLPDecodeStakeMsg(payload []byte, d Directive) (interface{}, error) {
 	var oops error

staking/types/validator.go

@@ -106,6 +106,83 @@ type Validator struct {
 	Banned bool
 }
 
+// SanityCheck checks basic requirements of a validator
+func (v *Validator) SanityCheck() error {
+	if _, err := v.EnsureLength(); err != nil {
+		return err
+	}
+
+	if len(v.SlotPubKeys) == 0 {
+		return errNeedAtLeastOneSlotKey
+	}
+
+	if v.MinSelfDelegation == nil {
+		return errNilMinSelfDelegation
+	}
+
+	if v.MaxTotalDelegation == nil {
+		return errNilMaxTotalDelegation
+	}
+
+	// MinSelfDelegation must be >= 1 ONE
+	if v.MinSelfDelegation.Cmp(big.NewInt(denominations.One)) < 0 {
+		return errors.Wrapf(
+			errMinSelfDelegationTooSmall,
+			"delegation-given %s", v.MinSelfDelegation.String(),
+		)
+	}
+
+	// MaxTotalDelegation must not be less than MinSelfDelegation
+	if v.MaxTotalDelegation.Cmp(v.MinSelfDelegation) < 0 {
+		return errors.Wrapf(
+			errInvalidMaxTotalDelegation,
+			"max-total-delegation %s min-self-delegation %s",
+			v.MaxTotalDelegation.String(),
+			v.MinSelfDelegation.String(),
+		)
+	}
+
+	if v.Rate.LT(zeroPercent) || v.Rate.GT(hundredPercent) {
+		return errors.Wrapf(
+			errInvalidCommissionRate, "rate:%s", v.Rate.String(),
+		)
+	}
+
+	if v.MaxRate.LT(zeroPercent) || v.MaxRate.GT(hundredPercent) {
+		return errors.Wrapf(
+			errInvalidCommissionRate, "rate:%s", v.MaxRate.String(),
+		)
+	}
+
+	if v.MaxChangeRate.LT(zeroPercent) || v.MaxChangeRate.GT(hundredPercent) {
+		return errors.Wrapf(
+			errInvalidCommissionRate, "rate:%s", v.MaxChangeRate.String(),
+		)
+	}
+
+	if v.Rate.GT(v.MaxRate) {
+		return errors.Wrapf(
+			errCommissionRateTooLarge, "rate:%s", v.MaxRate.String(),
+		)
+	}
+
+	if v.MaxChangeRate.GT(v.MaxRate) {
+		return errors.Wrapf(
+			errCommissionRateTooLarge, "rate:%s", v.MaxChangeRate.String(),
+		)
+	}
+
+	allKeys := map[shard.BlsPublicKey]struct{}{}
+	for i := range v.SlotPubKeys {
+		if _, ok := allKeys[v.SlotPubKeys[i]]; !ok {
+			allKeys[v.SlotPubKeys[i]] = struct{}{}
+		} else {
+			return errDuplicateSlotKeys
+		}
+	}
+	return nil
+}
+
 // MarshalJSON ..
 func (v *ValidatorStats) MarshalJSON() ([]byte, error) {
 	type t struct {
@@ -176,26 +253,9 @@ var (
 
 // SanityCheck checks the basic requirements
 func (w *ValidatorWrapper) SanityCheck() error {
-	if len(w.SlotPubKeys) == 0 {
+	if err := w.Validator.SanityCheck(); err != nil {
-		return errNeedAtLeastOneSlotKey
+		return err
-	}
-
-	if w.Validator.MinSelfDelegation == nil {
-		return errNilMinSelfDelegation
-	}
-
-	if w.Validator.MaxTotalDelegation == nil {
-		return errNilMaxTotalDelegation
-	}
-
-	// MinSelfDelegation must be >= 1 ONE
-	if w.Validator.MinSelfDelegation.Cmp(big.NewInt(denominations.One)) < 0 {
-		return errors.Wrapf(
-			errMinSelfDelegationTooSmall,
-			"delegation-given %s", w.Validator.MinSelfDelegation.String(),
-		)
 	}
-
 	// Self delegation must be >= MinSelfDelegation
 	switch len(w.Delegations) {
 	case 0:
@@ -210,17 +270,6 @@ func (w *ValidatorWrapper) SanityCheck() error {
 			)
 		}
 	}
-
-	// MaxTotalDelegation must not be less than MinSelfDelegation
-	if w.Validator.MaxTotalDelegation.Cmp(w.Validator.MinSelfDelegation) < 0 {
-		return errors.Wrapf(
-			errInvalidMaxTotalDelegation,
-			"max-total-delegation %s min-self-delegation %s",
-			w.Validator.MaxTotalDelegation.String(),
-			w.Validator.MinSelfDelegation.String(),
-		)
-	}
-
 	totalDelegation := w.TotalDelegation()
 	// Total delegation must be <= MaxTotalDelegation
 	if totalDelegation.Cmp(w.Validator.MaxTotalDelegation) > 0 {
@@ -231,45 +280,6 @@ func (w *ValidatorWrapper) SanityCheck() error {
 			w.Validator.MaxTotalDelegation.String(),
 		)
 	}
-
-	if w.Validator.Rate.LT(zeroPercent) || w.Validator.Rate.GT(hundredPercent) {
-		return errors.Wrapf(
-			errInvalidCommissionRate, "rate:%s", w.Validator.Rate.String(),
-		)
-	}
-
-	if w.Validator.MaxRate.LT(zeroPercent) || w.Validator.MaxRate.GT(hundredPercent) {
-		return errors.Wrapf(
-			errInvalidCommissionRate, "rate:%s", w.Validator.MaxRate.String(),
-		)
-	}
-
-	if w.Validator.MaxChangeRate.LT(zeroPercent) || w.Validator.MaxChangeRate.GT(hundredPercent) {
-		return errors.Wrapf(
-			errInvalidCommissionRate, "rate:%s", w.Validator.MaxChangeRate.String(),
-		)
-	}
-
-	if w.Validator.Rate.GT(w.Validator.MaxRate) {
-		return errors.Wrapf(
-			errCommissionRateTooLarge, "rate:%s", w.Validator.MaxRate.String(),
-		)
-	}
-
-	if w.Validator.MaxChangeRate.GT(w.Validator.MaxRate) {
-		return errors.Wrapf(
-			errCommissionRateTooLarge, "rate:%s", w.Validator.MaxChangeRate.String(),
-		)
-	}
-
-	allKeys := map[shard.BlsPublicKey]struct{}{}
-	for i := range w.Validator.SlotPubKeys {
-		if _, ok := allKeys[w.Validator.SlotPubKeys[i]]; !ok {
-			allKeys[w.Validator.SlotPubKeys[i]] = struct{}{}
-		} else {
-			return errDuplicateSlotKeys
-		}
-	}
 	return nil
 }
 
@@ -350,13 +360,15 @@ func (v *Validator) GetCommissionRate() numeric.Dec { return v.Commission.Rate }
 // GetMinSelfDelegation returns the minimum amount the validator must stake
 func (v *Validator) GetMinSelfDelegation() *big.Int { return v.MinSelfDelegation }
 
-func verifyBLSKeys(pubKeys []shard.BlsPublicKey, pubKeySigs []shard.BLSSignature) error {
+// VerifyBLSKeys checks if the public BLS key at index i of pubKeys matches the
+// BLS key signature at index i of pubKeysSigs.
+func VerifyBLSKeys(pubKeys []shard.BlsPublicKey, pubKeySigs []shard.BLSSignature) error {
 	if len(pubKeys) != len(pubKeySigs) {
 		return errBLSKeysNotMatchSigs
 	}
 
 	for i := 0; i < len(pubKeys); i++ {
-		if err := verifyBLSKey(&pubKeys[i], &pubKeySigs[i]); err != nil {
+		if err := VerifyBLSKey(&pubKeys[i], &pubKeySigs[i]); err != nil {
 			return err
 		}
 	}
@@ -364,7 +376,8 @@ func verifyBLSKeys(pubKeys []shard.BlsPublicKey, pubKeySigs []shard.BLSSignature
 	return nil
 }
 
-func verifyBLSKey(pubKey *shard.BlsPublicKey, pubKeySig *shard.BLSSignature) error {
+// VerifyBLSKey checks if the public BLS key matches the BLS signature
+func VerifyBLSKey(pubKey *shard.BlsPublicKey, pubKeySig *shard.BLSSignature) error {
 	if len(pubKeySig) == 0 {
 		return errBLSKeysNotMatchSigs
 	}
@@ -397,7 +410,7 @@ func CreateValidatorFromNewMsg(val *CreateValidator, blockNum *big.Int) (*Valida
 	commission := Commission{val.CommissionRates, blockNum}
 	pubKeys := append(val.SlotPubKeys[0:0], val.SlotPubKeys...)
 
-	if err = verifyBLSKeys(pubKeys, val.SlotKeySigs); err != nil {
+	if err = VerifyBLSKeys(pubKeys, val.SlotKeySigs); err != nil {
 		return nil, err
 	}
 
@@ -458,7 +471,7 @@ func UpdateValidatorFromEditMsg(validator *Validator, edit *EditValidator) error
 			}
 		}
 		if !found {
-			if err := verifyBLSKey(edit.SlotKeyToAdd, edit.SlotKeyToAddSig); err != nil {
+			if err := VerifyBLSKey(edit.SlotKeyToAdd, edit.SlotKeyToAddSig); err != nil {
 				return err
 			}
 			validator.SlotPubKeys = append(validator.SlotPubKeys, *edit.SlotKeyToAdd)

test/chain/main.go

@@ -129,7 +129,6 @@ func fundFaucetContract(chain *core.BlockChain) {
 
 	err := contractworker.CommitTransactions(
 		txmap, nil, testUserAddress,
-		func([]staking.RPCTransactionError) {},
 	)
 	if err != nil {
 		fmt.Println(err)
@@ -172,7 +171,6 @@ func callFaucetContractToFundAnAddress(chain *core.BlockChain) {
 
 	err = contractworker.CommitTransactions(
 		txmap, nil, testUserAddress,
-		func([]staking.RPCTransactionError) {},
 	)
 	if err != nil {
 		fmt.Println(err)
@@ -206,14 +204,19 @@ func main() {
 	genesis := gspec.MustCommit(database)
 	chain, _ := core.NewBlockChain(database, nil, gspec.Config, chain.Engine(), vm.Config{}, nil)
 
-	txpool := core.NewTxPool(core.DefaultTxPoolConfig, chainConfig, chain, func([]types.RPCTransactionError) {})
+	txpool := core.NewTxPool(core.DefaultTxPoolConfig, chainConfig, chain,
+		func([]types.RPCTransactionError) {}, func([]staking.RPCTransactionError) {})
 
 	backend := &testWorkerBackend{
 		db:     database,
 		chain:  chain,
 		txPool: txpool,
 	}
-	backend.txPool.AddLocals(pendingTxs)
+	poolPendingTx := types.PoolTransactions{}
+	for _, tx := range pendingTxs {
+		poolPendingTx = append(poolPendingTx, tx)
+	}
+	backend.txPool.AddLocals(poolPendingTx)
 
 	//// Generate a small n-block chain and an uncle block for it
 	n := 3