evm: use TransientStore for AccessList (#75)

* evm: use transient store for access list

* evm: remove address and slot access list mappings

* update tests

* update

* changelog

* update types

CHANGELOG.md

@@ -37,6 +37,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## Unreleased
 
+### State Machine Breaking
+
+* (evm) [tharsis#72](https://github.com/tharsis/ethermint/issues/72) Update `AccessList` to use `TransientStore` instead of map.
+
 ### API Breaking
 
 * (eth) [\#845](https://github.com/cosmos/ethermint/pull/845) The `eth` namespace must be included in the list of API's as default to run the rpc server without error.

x/evm/keeper/keeper.go

@@ -45,12 +45,6 @@ type Keeper struct {
 	// Ethermint concrete implementation on the EVM StateDB interface
 	CommitStateDB *types.CommitStateDB
 
-	// Per-transaction access list
-	// See EIP-2930 for more info: https://eips.ethereum.org/EIPS/eip-2930
-	// TODO: (@fedekunze) for how long should we persist the entries in the access list?
-	// same block (i.e Transient Store)? 2 or more (KVStore with module Parameter which resets the state after that window)?
-	accessList *types.AccessListMappings
-
 	// hash header for the current height. Reset during abci.RequestBeginBlock
 	headerHash common.Hash
 }
@@ -73,8 +67,7 @@ func NewKeeper(
 		bankKeeper:    bankKeeper,
 		storeKey:      storeKey,
 		transientKey:  transientKey,
-		CommitStateDB: types.NewCommitStateDB(sdk.Context{}, storeKey, paramSpace, ak, bankKeeper),
+		CommitStateDB: types.NewCommitStateDB(sdk.Context{}, storeKey, transientKey, paramSpace, ak, bankKeeper),
-		accessList:    types.NewAccessListMappings(),
 	}
 }
 

x/evm/keeper/statedb.go

@@ -493,37 +493,48 @@ func (k *Keeper) PrepareAccessList(sender common.Address, dest *common.Address,
 	}
 }
 
-// AddressInAccessList returns true if the address is registered on the access list map.
+// AddressInAccessList returns true if the address is registered on the transient store.
 func (k *Keeper) AddressInAccessList(addr common.Address) bool {
-	return k.accessList.ContainsAddress(addr)
+	ts := prefix.NewStore(k.ctx.TransientStore(k.transientKey), types.KeyPrefixTransientAccessListAddress)
+	return ts.Has(addr.Bytes())
 }
 
+// SlotInAccessList checks if the address and the slots are registered in the transient store
 func (k *Keeper) SlotInAccessList(addr common.Address, slot common.Hash) (addressOk bool, slotOk bool) {
-	return k.accessList.Contains(addr, slot)
+	addressOk = k.AddressInAccessList(addr)
+	slotOk = k.addressSlotInAccessList(addr, slot)
+	return addressOk, slotOk
 }
 
-// AddAddressToAccessList adds the given address to the access list. This operation is safe to perform
+// addressSlotInAccessList returns true if the address's slot is registered on the transient store.
-// even if the feature/fork is not active yet
+func (k *Keeper) addressSlotInAccessList(addr common.Address, slot common.Hash) bool {
+	ts := prefix.NewStore(k.ctx.TransientStore(k.transientKey), types.KeyPrefixTransientAccessListSlot)
+	key := append(addr.Bytes(), slot.Bytes()...)
+	return ts.Has(key)
+}
+
+// AddAddressToAccessList adds the given address to the access list. If the address is already
+// in the access list, this function performs a no-op.
 func (k *Keeper) AddAddressToAccessList(addr common.Address) {
-	// NOTE: only update the access list during DeliverTx
+	if k.AddressInAccessList(addr) {
-	if k.ctx.IsCheckTx() || k.ctx.IsReCheckTx() {
 		return
 	}
 
-	// NOTE: ignore change return bool because we don't have to keep a journal for state changes
+	ts := prefix.NewStore(k.ctx.TransientStore(k.transientKey), types.KeyPrefixTransientAccessListAddress)
-	_ = k.accessList.AddAddress(addr)
+	ts.Set(addr.Bytes(), []byte{0x1})
 }
 
-// AddSlotToAccessList adds the given (address,slot) to the access list. This operation is safe to perform
+// AddSlotToAccessList adds the given (address, slot) to the access list. If the address and slot are
-// even if the feature/fork is not active yet
+// already in the access list, this function performs a no-op.
 func (k *Keeper) AddSlotToAccessList(addr common.Address, slot common.Hash) {
-	// NOTE: only update the access list during DeliverTx
+	k.AddAddressToAccessList(addr)
-	if k.ctx.IsCheckTx() || k.ctx.IsReCheckTx() {
+	if k.addressSlotInAccessList(addr, slot) {
 		return
 	}
 
-	// NOTE: ignore change return booleans because we don't have to keep a journal for state changes
+	ts := prefix.NewStore(k.ctx.TransientStore(k.transientKey), types.KeyPrefixTransientAccessListSlot)
-	_, _ = k.accessList.AddSlot(addr, slot)
+	key := append(addr.Bytes(), slot.Bytes()...)
+	ts.Set(key, []byte{0x1})
 }
 
 // ----------------------------------------------------------------------------

x/evm/keeper/statedb_test.go

@@ -506,7 +506,7 @@ func (suite *KeeperTestSuite) TestAddLog() {
 	}
 }
 
-func (suite *KeeperTestSuite) TestAccessList() {
+func (suite *KeeperTestSuite) TestPrepareAccessList() {
 	dest := tests.GenerateAddress()
 	precompiles := []common.Address{tests.GenerateAddress(), tests.GenerateAddress()}
 	accesses := ethtypes.AccessList{
@@ -526,12 +526,52 @@ func (suite *KeeperTestSuite) TestAccessList() {
 	for _, access := range accesses {
 		for _, key := range access.StorageKeys {
 			addrOK, slotOK := suite.app.EvmKeeper.SlotInAccessList(access.Address, key)
-			suite.Require().True(addrOK)
+			suite.Require().True(addrOK, access.Address.Hex())
-			suite.Require().True(slotOK)
+			suite.Require().True(slotOK, key.Hex())
 		}
 	}
 }
 
+func (suite *KeeperTestSuite) TestAddAddressToAccessList() {
+	testCases := []struct {
+		name string
+		addr common.Address
+	}{
+		{"new address", suite.address},
+		{"existing address", suite.address},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(tc.name, func() {
+			suite.app.EvmKeeper.AddAddressToAccessList(tc.addr)
+			addrOk := suite.app.EvmKeeper.AddressInAccessList(tc.addr)
+			suite.Require().True(addrOk, tc.addr.Hex())
+		})
+	}
+}
+
+func (suite *KeeperTestSuite) AddSlotToAccessList() {
+	testCases := []struct {
+		name string
+		addr common.Address
+		slot common.Hash
+	}{
+		{"new address and slot (1)", tests.GenerateAddress(), common.BytesToHash([]byte("hash"))},
+		{"new address and slot (2)", suite.address, common.Hash{}},
+		{"existing address and slot", suite.address, common.Hash{}},
+		{"existing address, new slot", suite.address, common.BytesToHash([]byte("hash"))},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(tc.name, func() {
+			suite.app.EvmKeeper.AddSlotToAccessList(tc.addr, tc.slot)
+			addrOk, slotOk := suite.app.EvmKeeper.SlotInAccessList(tc.addr, tc.slot)
+			suite.Require().True(addrOk, tc.addr.Hex())
+			suite.Require().True(slotOk, tc.slot.Hex())
+		})
+	}
+}
+
 func (suite *KeeperTestSuite) TestForEachStorage() {
 	var storage types.Storage
 

x/evm/types/access_list.go

@@ -1,140 +1,10 @@
 package types
 
 import (
-	"github.com/ethereum/go-ethereum/common"
 	ethcmn "github.com/ethereum/go-ethereum/common"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 )
 
-// AccessListMappings is copied from go-ethereum
-// https://github.com/ethereum/go-ethereum/blob/cf856ea1ad96ac39ea477087822479b63417036a/core/state/access_list.go#L23
-type AccessListMappings struct {
-	addresses map[common.Address]int
-	slots     []map[common.Hash]struct{}
-}
-
-// ContainsAddress returns true if the address is in the access list.
-func (al *AccessListMappings) ContainsAddress(address common.Address) bool {
-	_, ok := al.addresses[address]
-	return ok
-}
-
-// Contains checks if a slot within an account is present in the access list, returning
-// separate flags for the presence of the account and the slot respectively.
-func (al *AccessListMappings) Contains(address common.Address, slot common.Hash) (addressPresent bool, slotPresent bool) {
-	idx, ok := al.addresses[address]
-	if !ok {
-		// no such address (and hence zero slots)
-		return false, false
-	}
-	if idx == -1 {
-		// address yes, but no slots
-		return true, false
-	}
-
-	if idx >= len(al.slots) {
-		// return in case of out-of-range
-		return true, false
-	}
-
-	_, slotPresent = al.slots[idx][slot]
-	return true, slotPresent
-}
-
-// newAccessList creates a new AccessListMappings.
-func NewAccessListMappings() *AccessListMappings {
-	return &AccessListMappings{
-		addresses: make(map[common.Address]int),
-	}
-}
-
-// Copy creates an independent copy of an AccessListMappings.
-func (al *AccessListMappings) Copy() *AccessListMappings {
-	cp := NewAccessListMappings()
-	for k, v := range al.addresses {
-		cp.addresses[k] = v
-	}
-	cp.slots = make([]map[common.Hash]struct{}, len(al.slots))
-	for i, slotMap := range al.slots {
-		newSlotmap := make(map[common.Hash]struct{}, len(slotMap))
-		for k := range slotMap {
-			newSlotmap[k] = struct{}{}
-		}
-		cp.slots[i] = newSlotmap
-	}
-	return cp
-}
-
-// AddAddress adds an address to the access list, and returns 'true' if the operation
-// caused a change (addr was not previously in the list).
-func (al *AccessListMappings) AddAddress(address common.Address) bool {
-	if _, present := al.addresses[address]; present {
-		return false
-	}
-	al.addresses[address] = -1
-	return true
-}
-
-// AddSlot adds the specified (addr, slot) combo to the access list.
-// Return values are:
-// - address added
-// - slot added
-// For any 'true' value returned, a corresponding journal entry must be made.
-func (al *AccessListMappings) AddSlot(address common.Address, slot common.Hash) (addrChange bool, slotChange bool) {
-	idx, addrPresent := al.addresses[address]
-	if !addrPresent || idx == -1 {
-		// Address not present, or addr present but no slots there
-		al.addresses[address] = len(al.slots)
-		slotmap := map[common.Hash]struct{}{slot: {}}
-		al.slots = append(al.slots, slotmap)
-		return !addrPresent, true
-	}
-
-	if idx >= len(al.slots) {
-		// return in case of out-of-range
-		return false, false
-	}
-
-	// There is already an (address,slot) mapping
-	slotmap := al.slots[idx]
-	if _, ok := slotmap[slot]; !ok {
-		slotmap[slot] = struct{}{}
-		// journal add slot change
-		return false, true
-	}
-	// No changes required
-	return false, false
-}
-
-// DeleteSlot removes an (address, slot)-tuple from the access list.
-// This operation needs to be performed in the same order as the addition happened.
-// This method is meant to be used  by the journal, which maintains ordering of
-// operations.
-func (al *AccessListMappings) DeleteSlot(address common.Address, slot common.Hash) {
-	idx, addrOk := al.addresses[address]
-	// There are two ways this can fail
-	if !addrOk {
-		panic("reverting slot change, address not present in list")
-	}
-	slotmap := al.slots[idx]
-	delete(slotmap, slot)
-	// If that was the last (first) slot, remove it
-	// Since additions and rollbacks are always performed in order,
-	// we can delete the item without worrying about screwing up later indices
-	if len(slotmap) == 0 {
-		al.slots = al.slots[:idx]
-		al.addresses[address] = -1
-	}
-}
-
-// DeleteAddress removes an address from the access list. This operation
-// needs to be performed in the same order as the addition happened.
-// This method is meant to be used  by the journal, which maintains ordering of
-// operations.
-func (al *AccessListMappings) DeleteAddress(address common.Address) {
-	delete(al.addresses, address)
-}
-
 // AccessList is an EIP-2930 access list that represents the slice of
 // the protobuf AccessTuples.
 type AccessList []AccessTuple

x/evm/types/access_list_test.go

@@ -1,242 +0,0 @@
-package types
-
-import (
-	"fmt"
-	"testing"
-
-	"github.com/stretchr/testify/suite"
-
-	ethcmn "github.com/ethereum/go-ethereum/common"
-
-	"github.com/cosmos/ethermint/crypto/ethsecp256k1"
-)
-
-type AccessListTestSuite struct {
-	suite.Suite
-
-	address    ethcmn.Address
-	accessList *AccessListMappings
-}
-
-func (suite *AccessListTestSuite) SetupTest() {
-	privkey, err := ethsecp256k1.GenerateKey()
-	suite.Require().NoError(err)
-
-	suite.address = ethcmn.BytesToAddress(privkey.PubKey().Address().Bytes())
-	suite.accessList = NewAccessListMappings()
-	suite.accessList.addresses[suite.address] = 1
-}
-
-func TestAccessListTestSuite(t *testing.T) {
-	suite.Run(t, new(AccessListTestSuite))
-}
-
-func (suite *AccessListTestSuite) TestContainsAddress() {
-	found := suite.accessList.ContainsAddress(suite.address)
-	suite.Require().True(found)
-}
-
-func (suite *AccessListTestSuite) TestContains() {
-	testCases := []struct {
-		name           string
-		malleate       func()
-		expAddrPresent bool
-		expSlotPresent bool
-	}{
-		{"out of range", func() {}, true, false},
-		{
-			"address, no slots",
-			func() {
-				suite.accessList.addresses[suite.address] = -1
-			}, true, false,
-		},
-		{
-			"no address, no slots",
-			func() {
-				delete(suite.accessList.addresses, suite.address)
-			}, false, false,
-		},
-		{
-			"address, slot not present",
-			func() {
-				suite.accessList.addresses[suite.address] = 0
-				suite.accessList.slots = make([]map[ethcmn.Hash]struct{}, 1)
-			}, true, false,
-		},
-		{
-			"address, slots",
-			func() {
-				suite.accessList.addresses[suite.address] = 0
-				suite.accessList.slots = make([]map[ethcmn.Hash]struct{}, 1)
-				suite.accessList.slots[0] = make(map[ethcmn.Hash]struct{})
-				suite.accessList.slots[0][ethcmn.Hash{}] = struct{}{}
-			}, true, true,
-		},
-	}
-
-	for _, tc := range testCases {
-		tc.malleate()
-
-		addrPresent, slotPresent := suite.accessList.Contains(suite.address, ethcmn.Hash{})
-
-		suite.Require().Equal(tc.expAddrPresent, addrPresent, tc.name)
-		suite.Require().Equal(tc.expSlotPresent, slotPresent, tc.name)
-	}
-}
-
-func (suite *AccessListTestSuite) TestCopy() {
-	expAccessList := NewAccessListMappings()
-
-	testCases := []struct {
-		name     string
-		malleate func()
-	}{
-		{"empty", func() {
-			expAccessList.slots = make([]map[ethcmn.Hash]struct{}, 0)
-		}},
-		{
-			"single address", func() {
-				expAccessList = NewAccessListMappings()
-				expAccessList.slots = make([]map[ethcmn.Hash]struct{}, 0)
-				expAccessList.addresses[suite.address] = -1
-			},
-		},
-		{
-			"single address, single slot",
-			func() {
-				expAccessList = NewAccessListMappings()
-				expAccessList.addresses[suite.address] = 0
-				expAccessList.slots = make([]map[ethcmn.Hash]struct{}, 1)
-				expAccessList.slots[0] = make(map[ethcmn.Hash]struct{})
-				expAccessList.slots[0][ethcmn.Hash{}] = struct{}{}
-			},
-		},
-		{
-			"multiple addresses, single slot each",
-			func() {
-				expAccessList = NewAccessListMappings()
-				expAccessList.slots = make([]map[ethcmn.Hash]struct{}, 10)
-				for i := 0; i < 10; i++ {
-					expAccessList.addresses[ethcmn.BytesToAddress([]byte(fmt.Sprintf("%d", i)))] = i
-					expAccessList.slots[i] = make(map[ethcmn.Hash]struct{})
-					expAccessList.slots[i][ethcmn.BytesToHash([]byte(fmt.Sprintf("%d", i)))] = struct{}{}
-				}
-			},
-		},
-		{
-			"multiple addresses, multiple slots each",
-			func() {
-				expAccessList = NewAccessListMappings()
-				expAccessList.slots = make([]map[ethcmn.Hash]struct{}, 10)
-				for i := 0; i < 10; i++ {
-					expAccessList.addresses[ethcmn.BytesToAddress([]byte(fmt.Sprintf("%d", i)))] = i
-					expAccessList.slots[i] = make(map[ethcmn.Hash]struct{})
-					for j := 0; j < 10; j++ {
-						expAccessList.slots[i][ethcmn.BytesToHash([]byte(fmt.Sprintf("%d-%d", i, j)))] = struct{}{}
-					}
-				}
-			},
-		},
-	}
-
-	for _, tc := range testCases {
-		tc.malleate()
-
-		accessList := expAccessList.Copy()
-		suite.Require().EqualValues(expAccessList, accessList, tc.name)
-	}
-}
-
-func (suite *AccessListTestSuite) TestAddAddress() {
-	testCases := []struct {
-		name    string
-		address ethcmn.Address
-		ok      bool
-	}{
-		{"already present", suite.address, false},
-		{"ok", ethcmn.Address{}, true},
-	}
-
-	for _, tc := range testCases {
-		ok := suite.accessList.AddAddress(tc.address)
-		suite.Require().Equal(tc.ok, ok, tc.name)
-	}
-}
-
-func (suite *AccessListTestSuite) TestAddSlot() {
-	testCases := []struct {
-		name          string
-		malleate      func()
-		expAddrChange bool
-		expSlotChange bool
-	}{
-		{"out of range", func() {}, false, false},
-		{
-			"address not present added, slot added",
-			func() {
-				delete(suite.accessList.addresses, suite.address)
-			}, true, true,
-		},
-		{
-			"address present, slot not present added",
-			func() {
-				suite.accessList.addresses[suite.address] = 0
-				suite.accessList.slots = make([]map[ethcmn.Hash]struct{}, 1)
-				suite.accessList.slots[0] = make(map[ethcmn.Hash]struct{})
-			}, false, true,
-		},
-		{
-			"address present, slot present",
-			func() {
-				suite.accessList.addresses[suite.address] = 0
-				suite.accessList.slots = make([]map[ethcmn.Hash]struct{}, 1)
-				suite.accessList.slots[0] = make(map[ethcmn.Hash]struct{})
-				suite.accessList.slots[0][ethcmn.Hash{}] = struct{}{}
-			}, false, false,
-		},
-	}
-
-	for _, tc := range testCases {
-		tc.malleate()
-
-		addrChange, slotChange := suite.accessList.AddSlot(suite.address, ethcmn.Hash{})
-		suite.Require().Equal(tc.expAddrChange, addrChange, tc.name)
-		suite.Require().Equal(tc.expSlotChange, slotChange, tc.name)
-	}
-}
-
-func (suite *AccessListTestSuite) TestDeleteSlot() {
-	testCases := []struct {
-		name     string
-		malleate func()
-		expPanic bool
-	}{
-		{"panics, out of range", func() {}, true},
-		{"panics, address not found", func() {
-			delete(suite.accessList.addresses, suite.address)
-		}, true},
-		{
-			"single slot present",
-			func() {
-				suite.accessList.addresses[suite.address] = 0
-				suite.accessList.slots = make([]map[ethcmn.Hash]struct{}, 1)
-				suite.accessList.slots[0] = make(map[ethcmn.Hash]struct{})
-				suite.accessList.slots[0][ethcmn.Hash{}] = struct{}{}
-			}, false,
-		},
-	}
-
-	for _, tc := range testCases {
-		tc.malleate()
-
-		if tc.expPanic {
-			suite.Require().Panics(func() {
-				suite.accessList.DeleteSlot(suite.address, ethcmn.Hash{})
-			}, tc.name)
-		} else {
-			suite.Require().NotPanics(func() {
-				suite.accessList.DeleteSlot(suite.address, ethcmn.Hash{})
-			}, tc.name)
-		}
-	}
-}

x/evm/types/journal.go

@@ -364,7 +364,7 @@ func (ch accessListAddAccountChange) revert(s *CommitStateDB) {
 		(addr) at this point, since no storage adds can remain when come upon
 		a single (addr) change.
 	*/
-	s.accessList.DeleteAddress(*ch.address)
+	// s.accessList.DeleteAddress(*ch.address)
 }
 
 func (ch accessListAddAccountChange) dirtied() *ethcmn.Address {
@@ -372,7 +372,7 @@ func (ch accessListAddAccountChange) dirtied() *ethcmn.Address {
 }
 
 func (ch accessListAddSlotChange) revert(s *CommitStateDB) {
-	s.accessList.DeleteSlot(*ch.address, *ch.slot)
+	// s.accessList.DeleteSlot(*ch.address, *ch.slot)
 }
 
 func (ch accessListAddSlotChange) dirtied() *ethcmn.Address {

x/evm/types/journal_test.go

@@ -104,6 +104,7 @@ func (suite *JournalTestSuite) setup() {
 	authKey := sdk.NewKVStoreKey(authtypes.StoreKey)
 	paramsKey := sdk.NewKVStoreKey(paramtypes.StoreKey)
 	paramsTKey := sdk.NewTransientStoreKey(paramtypes.TStoreKey)
+	tKey := sdk.NewTransientStoreKey(TransientKey)
 	bankKey := sdk.NewKVStoreKey(banktypes.StoreKey)
 	storeKey := sdk.NewKVStoreKey(StoreKey)
 
@@ -120,6 +121,7 @@ func (suite *JournalTestSuite) setup() {
 	cms.MountStoreWithDB(paramsKey, sdk.StoreTypeIAVL, db)
 	cms.MountStoreWithDB(storeKey, sdk.StoreTypeIAVL, db)
 	cms.MountStoreWithDB(paramsTKey, sdk.StoreTypeTransient, db)
+	cms.MountStoreWithDB(tKey, sdk.StoreTypeTransient, db)
 
 	err = cms.LoadLatestVersion()
 	suite.Require().NoError(err)
@@ -135,7 +137,7 @@ func (suite *JournalTestSuite) setup() {
 	ak := authkeeper.NewAccountKeeper(cdc, authKey, authSubspace, ethermint.ProtoAccount, nil)
 	bk := bankkeeper.NewBaseKeeper(cdc, bankKey, ak, bankSubspace, nil)
 	suite.ctx = sdk.NewContext(cms, tmproto.Header{ChainID: "ethermint-8"}, false, tmlog.NewNopLogger())
-	suite.stateDB = NewCommitStateDB(suite.ctx, storeKey, evmSubspace, ak, bk).WithContext(suite.ctx)
+	suite.stateDB = NewCommitStateDB(suite.ctx, storeKey, tKey, evmSubspace, ak, bk).WithContext(suite.ctx)
 	suite.stateDB.SetParams(DefaultParams())
 }
 

x/evm/types/key.go

@@ -40,6 +40,8 @@ const (
 	prefixTransientBloom
 	prefixTransientTxIndex
 	prefixTransientRefund
+	prefixTransientAccessListAddress
+	prefixTransientAccessListSlot
 )
 
 // KVStore key prefixes
@@ -59,6 +61,8 @@ var (
 	KeyPrefixTransientBloom             = []byte{prefixTransientBloom}
 	KeyPrefixTransientTxIndex           = []byte{prefixTransientTxIndex}
 	KeyPrefixTransientRefund            = []byte{prefixTransientRefund}
+	KeyPrefixTransientAccessListAddress = []byte{prefixTransientAccessListAddress}
+	KeyPrefixTransientAccessListSlot    = []byte{prefixTransientAccessListSlot}
 )
 
 // BloomKey defines the store key for a block Bloom

x/evm/types/statedb.go

@@ -38,6 +38,7 @@ type CommitStateDB struct {
 	ctx sdk.Context
 
 	storeKey      sdk.StoreKey
+	transientKey  sdk.StoreKey
 	paramSpace    paramtypes.Subspace
 	accountKeeper AccountKeeper
 	bankKeeper    BankKeeper
@@ -73,9 +74,6 @@ type CommitStateDB struct {
 	validRevisions []revision
 	nextRevisionID int
 
-	// Per-transaction access list
-	accessList *AccessListMappings
-
 	// mutex for state deep copying
 	lock sync.Mutex
 }
@@ -86,12 +84,13 @@ type CommitStateDB struct {
 // CONTRACT: Stores used for state must be cache-wrapped as the ordering of the
 // key/value space matters in determining the merkle root.
 func NewCommitStateDB(
-	ctx sdk.Context, storeKey sdk.StoreKey, paramSpace paramtypes.Subspace,
+	ctx sdk.Context, storeKey, tKey sdk.StoreKey, paramSpace paramtypes.Subspace,
 	ak AccountKeeper, bankKeeper BankKeeper,
 ) *CommitStateDB {
 	return &CommitStateDB{
 		ctx:                  ctx,
 		storeKey:             storeKey,
+		transientKey:         tKey,
 		paramSpace:           paramSpace,
 		accountKeeper:        ak,
 		bankKeeper:           bankKeeper,
@@ -101,7 +100,6 @@ func NewCommitStateDB(
 		preimages:            []preimageEntry{},
 		hashToPreimageIndex:  make(map[ethcmn.Hash]int),
 		journal:              newJournal(),
-		accessList:           NewAccessListMappings(),
 	}
 }
 
@@ -253,40 +251,9 @@ func (csdb *CommitStateDB) SubRefund(gas uint64) {
 	csdb.refund -= gas
 }
 
-// AddAddressToAccessList adds the given address to the access list
+// ----------------------------------------------------------------------------
-func (csdb *CommitStateDB) AddAddressToAccessList(addr ethcmn.Address) {
+// Access List // TODO: deprecate
-	if csdb.accessList.AddAddress(addr) {
+// ----------------------------------------------------------------------------
-		csdb.journal.append(accessListAddAccountChange{&addr})
-	}
-}
-
-// AddSlotToAccessList adds the given (address, slot)-tuple to the access list
-func (csdb *CommitStateDB) AddSlotToAccessList(addr ethcmn.Address, slot ethcmn.Hash) {
-	addrMod, slotMod := csdb.accessList.AddSlot(addr, slot)
-	if addrMod {
-		// In practice, this should not happen, since there is no way to enter the
-		// scope of 'address' without having the 'address' become already added
-		// to the access list (via call-variant, create, etc).
-		// Better safe than sorry, though
-		csdb.journal.append(accessListAddAccountChange{&addr})
-	}
-	if slotMod {
-		csdb.journal.append(accessListAddSlotChange{
-			address: &addr,
-			slot:    &slot,
-		})
-	}
-}
-
-// AddressInAccessList returns true if the given address is in the access list.
-func (csdb *CommitStateDB) AddressInAccessList(addr ethcmn.Address) bool {
-	return csdb.accessList.ContainsAddress(addr)
-}
-
-// SlotInAccessList returns true if the given (address, slot)-tuple is in the access list.
-func (csdb *CommitStateDB) SlotInAccessList(addr ethcmn.Address, slot ethcmn.Hash) (bool, bool) {
-	return csdb.accessList.Contains(addr, slot)
-}
 
 // PrepareAccessList handles the preparatory steps for executing a state transition with
 // regards to both EIP-2929 and EIP-2930:
@@ -297,23 +264,65 @@ func (csdb *CommitStateDB) SlotInAccessList(addr ethcmn.Address, slot ethcmn.Has
 // 	- Add the contents of the optional tx access list (2930)
 //
 // This method should only be called if Yolov3/Berlin/2929+2930 is applicable at the current number.
-func (csdb *CommitStateDB) PrepareAccessList(sender ethcmn.Address, dst *ethcmn.Address, precompiles []ethcmn.Address, list ethtypes.AccessList) {
+func (csdb *CommitStateDB) PrepareAccessList(sender ethcmn.Address, dest *ethcmn.Address, precompiles []ethcmn.Address, txAccesses ethtypes.AccessList) {
 	csdb.AddAddressToAccessList(sender)
-	if dst != nil {
+	if dest != nil {
-		csdb.AddAddressToAccessList(*dst)
+		csdb.AddAddressToAccessList(*dest)
 		// If it's a create-tx, the destination will be added inside evm.create
 	}
 	for _, addr := range precompiles {
 		csdb.AddAddressToAccessList(addr)
 	}
-	for _, el := range list {
+	for _, tuple := range txAccesses {
-		csdb.AddAddressToAccessList(el.Address)
+		csdb.AddAddressToAccessList(tuple.Address)
-		for _, key := range el.StorageKeys {
+		for _, key := range tuple.StorageKeys {
-			csdb.AddSlotToAccessList(el.Address, key)
+			csdb.AddSlotToAccessList(tuple.Address, key)
 		}
 	}
 }
 
+// AddressInAccessList returns true if the address is registered on the access list map.
+func (csdb *CommitStateDB) AddressInAccessList(addr ethcmn.Address) bool {
+	ts := prefix.NewStore(csdb.ctx.TransientStore(csdb.transientKey), KeyPrefixTransientAccessListAddress)
+	return ts.Has(addr.Bytes())
+}
+
+func (csdb *CommitStateDB) SlotInAccessList(addr ethcmn.Address, slot ethcmn.Hash) (addressOk bool, slotOk bool) {
+	addressOk = csdb.AddressInAccessList(addr)
+	slotOk = csdb.addressSlotInAccessList(addr, slot)
+	return addressOk, slotOk
+}
+
+func (csdb *CommitStateDB) addressSlotInAccessList(addr ethcmn.Address, slot ethcmn.Hash) bool {
+	ts := prefix.NewStore(csdb.ctx.TransientStore(csdb.transientKey), KeyPrefixTransientAccessListSlot)
+	key := append(addr.Bytes(), slot.Bytes()...)
+	return ts.Has(key)
+}
+
+// AddAddressToAccessList adds the given address to the access list. This operation is safe to perform
+// even if the feature/fork is not active yet
+func (csdb *CommitStateDB) AddAddressToAccessList(addr ethcmn.Address) {
+	if csdb.AddressInAccessList(addr) {
+		return
+	}
+
+	ts := prefix.NewStore(csdb.ctx.TransientStore(csdb.transientKey), KeyPrefixTransientAccessListAddress)
+	ts.Set(addr.Bytes(), []byte{0x1})
+}
+
+// AddSlotToAccessList adds the given (address,slot) to the access list. This operation is safe to perform
+// even if the feature/fork is not active yet
+func (csdb *CommitStateDB) AddSlotToAccessList(addr ethcmn.Address, slot ethcmn.Hash) {
+	csdb.AddAddressToAccessList(addr)
+	if csdb.addressSlotInAccessList(addr, slot) {
+		return
+	}
+
+	ts := prefix.NewStore(csdb.ctx.TransientStore(csdb.transientKey), KeyPrefixTransientAccessListSlot)
+	key := append(addr.Bytes(), slot.Bytes()...)
+	ts.Set(key, []byte{0x1})
+}
+
 // ----------------------------------------------------------------------------
 // Getters
 // ----------------------------------------------------------------------------
@@ -721,7 +730,6 @@ func (csdb *CommitStateDB) Reset(_ ethcmn.Hash) error {
 	csdb.logSize = 0
 	csdb.preimages = []preimageEntry{}
 	csdb.hashToPreimageIndex = make(map[ethcmn.Hash]int)
-	csdb.accessList = NewAccessListMappings()
 
 	csdb.clearJournalAndRefund()
 	return nil
@@ -824,7 +832,6 @@ func CopyCommitStateDB(from, to *CommitStateDB) {
 	copy(validRevisions, from.validRevisions)
 	to.validRevisions = validRevisions
 	to.nextRevisionID = from.nextRevisionID
-	to.accessList = from.accessList.Copy()
 
 	// copy the dirty states, logs, and preimages
 	for _, dirty := range from.journal.dirties {