core/state: extend snapshotter to handle account resurrections

core/blockchain.go

@@ -198,6 +198,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 			TrieDirtyLimit: 256,
 			TrieTimeLimit:  5 * time.Minute,
 			SnapshotLimit:  256,
+			SnapshotWait:   true,
 		}
 	}
 	bodyCache, _ := lru.New(bodyCacheLimit)

core/blockchain_test.go

@@ -2315,7 +2315,7 @@ func TestDeleteCreateRevert(t *testing.T) {
 				// The address 0xAAAAA selfdestructs if called
 				aa: {
 					// Code needs to just selfdestruct
-					Code:    []byte{byte(vm.PC), 0xFF},
+					Code:    []byte{byte(vm.PC), byte(vm.SELFDESTRUCT)},
 					Nonce:   1,
 					Balance: big.NewInt(0),
 				},
@@ -2382,8 +2382,8 @@ func TestDeleteRecreateSlots(t *testing.T) {
 
 		aa        = common.HexToAddress("0x7217d81b76bdd8707601e959454e3d776aee5f43")
 		bb        = common.HexToAddress("0x000000000000000000000000000000000000bbbb")
-		aaStorage = make(map[common.Hash]common.Hash) // Initial storage in AA
-		aaCode    = []byte{byte(vm.PC), 0xFF}         // Code for AA (simple selfdestruct)
+		aaStorage = make(map[common.Hash]common.Hash)          // Initial storage in AA
+		aaCode    = []byte{byte(vm.PC), byte(vm.SELFDESTRUCT)} // Code for AA (simple selfdestruct)
 	)
 	// Populate two slots
 	aaStorage[common.HexToHash("01")] = common.HexToHash("01")
@@ -2506,8 +2506,8 @@ func TestDeleteRecreateAccount(t *testing.T) {
 		funds   = big.NewInt(1000000000)
 
 		aa        = common.HexToAddress("0x7217d81b76bdd8707601e959454e3d776aee5f43")
-		aaStorage = make(map[common.Hash]common.Hash) // Initial storage in AA
-		aaCode    = []byte{byte(vm.PC), 0xFF}         // Code for AA (simple selfdestruct)
+		aaStorage = make(map[common.Hash]common.Hash)          // Initial storage in AA
+		aaCode    = []byte{byte(vm.PC), byte(vm.SELFDESTRUCT)} // Code for AA (simple selfdestruct)
 	)
 	// Populate two slots
 	aaStorage[common.HexToHash("01")] = common.HexToHash("01")

core/state/snapshot/difflayer.go

@@ -27,7 +27,6 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/steakknife/bloomfilter"
 )
@@ -68,17 +67,28 @@ var (
 	// entry count).
 	bloomFuncs = math.Round((bloomSize / float64(aggregatorItemLimit)) * math.Log(2))
 
-	// bloomHashesOffset is a runtime constant which determines which part of the
+	// the bloom offsets are runtime constants which determines which part of the
 	// the account/storage hash the hasher functions looks at, to determine the
 	// bloom key for an account/slot. This is randomized at init(), so that the
 	// global population of nodes do not all display the exact same behaviour with
 	// regards to bloom content
-	bloomHasherOffset = 0
+	bloomDestructHasherOffset = 0
+	bloomAccountHasherOffset  = 0
+	bloomStorageHasherOffset  = 0
 )
 
 func init() {
-	// Init bloomHasherOffset in the range [0:24] (requires 8 bytes)
-	bloomHasherOffset = rand.Intn(25)
+	// Init the bloom offsets in the range [0:24] (requires 8 bytes)
+	bloomDestructHasherOffset = rand.Intn(25)
+	bloomAccountHasherOffset = rand.Intn(25)
+	bloomStorageHasherOffset = rand.Intn(25)
+
+	// The destruct and account blooms must be different, as the storage slots
+	// will check for destruction too for every bloom miss. It should not collide
+	// with modified accounts.
+	for bloomAccountHasherOffset == bloomDestructHasherOffset {
+		bloomAccountHasherOffset = rand.Intn(25)
+	}
 }
 
 // diffLayer represents a collection of modifications made to a state snapshot
@@ -95,6 +105,7 @@ type diffLayer struct {
 	root  common.Hash // Root hash to which this snapshot diff belongs to
 	stale uint32      // Signals that the layer became stale (state progressed)
 
+	destructSet map[common.Hash]struct{}               // Keyed markers for deleted (and potentially) recreated accounts
 	accountList []common.Hash                          // List of account for iteration. If it exists, it's sorted, otherwise it's nil
 	accountData map[common.Hash][]byte                 // Keyed accounts for direct retrival (nil means deleted)
 	storageList map[common.Hash][]common.Hash          // List of storage slots for iterated retrievals, one per account. Any existing lists are sorted if non-nil
@@ -105,6 +116,20 @@ type diffLayer struct {
 	lock sync.RWMutex
 }
 
+// destructBloomHasher is a wrapper around a common.Hash to satisfy the interface
+// API requirements of the bloom library used. It's used to convert a destruct
+// event into a 64 bit mini hash.
+type destructBloomHasher common.Hash
+
+func (h destructBloomHasher) Write(p []byte) (n int, err error) { panic("not implemented") }
+func (h destructBloomHasher) Sum(b []byte) []byte               { panic("not implemented") }
+func (h destructBloomHasher) Reset()                            { panic("not implemented") }
+func (h destructBloomHasher) BlockSize() int                    { panic("not implemented") }
+func (h destructBloomHasher) Size() int                         { return 8 }
+func (h destructBloomHasher) Sum64() uint64 {
+	return binary.BigEndian.Uint64(h[bloomDestructHasherOffset : bloomDestructHasherOffset+8])
+}
+
 // accountBloomHasher is a wrapper around a common.Hash to satisfy the interface
 // API requirements of the bloom library used. It's used to convert an account
 // hash into a 64 bit mini hash.
@@ -116,7 +141,7 @@ func (h accountBloomHasher) Reset()                            { panic("not impl
 func (h accountBloomHasher) BlockSize() int                    { panic("not implemented") }
 func (h accountBloomHasher) Size() int                         { return 8 }
 func (h accountBloomHasher) Sum64() uint64 {
-	return binary.BigEndian.Uint64(h[bloomHasherOffset : bloomHasherOffset+8])
+	return binary.BigEndian.Uint64(h[bloomAccountHasherOffset : bloomAccountHasherOffset+8])
 }
 
 // storageBloomHasher is a wrapper around a [2]common.Hash to satisfy the interface
@@ -130,17 +155,18 @@ func (h storageBloomHasher) Reset()                            { panic("not impl
 func (h storageBloomHasher) BlockSize() int                    { panic("not implemented") }
 func (h storageBloomHasher) Size() int                         { return 8 }
 func (h storageBloomHasher) Sum64() uint64 {
-	return binary.BigEndian.Uint64(h[0][bloomHasherOffset:bloomHasherOffset+8]) ^
-		binary.BigEndian.Uint64(h[1][bloomHasherOffset:bloomHasherOffset+8])
+	return binary.BigEndian.Uint64(h[0][bloomStorageHasherOffset:bloomStorageHasherOffset+8]) ^
+		binary.BigEndian.Uint64(h[1][bloomStorageHasherOffset:bloomStorageHasherOffset+8])
 }
 
 // newDiffLayer creates a new diff on top of an existing snapshot, whether that's a low
 // level persistent database or a hierarchical diff already.
-func newDiffLayer(parent snapshot, root common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
+func newDiffLayer(parent snapshot, root common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
 	// Create the new layer with some pre-allocated data segments
 	dl := &diffLayer{
 		parent:      parent,
 		root:        root,
+		destructSet: destructs,
 		accountData: accounts,
 		storageData: storage,
 	}
@@ -152,6 +178,17 @@ func newDiffLayer(parent snapshot, root common.Hash, accounts map[common.Hash][]
 	default:
 		panic("unknown parent type")
 	}
+	// Sanity check that accounts or storage slots are never nil
+	for accountHash, blob := range accounts {
+		if blob == nil {
+			panic(fmt.Sprintf("account %#x nil", accountHash))
+		}
+	}
+	for accountHash, slots := range storage {
+		if slots == nil {
+			panic(fmt.Sprintf("storage %#x nil", accountHash))
+		}
+	}
 	// Determine memory size and track the dirty writes
 	for _, data := range accounts {
 		dl.memory += uint64(common.HashLength + len(data))
@@ -159,24 +196,11 @@ func newDiffLayer(parent snapshot, root common.Hash, accounts map[common.Hash][]
 	}
 	// Fill the storage hashes and sort them for the iterator
 	dl.storageList = make(map[common.Hash][]common.Hash)
-
-	for accountHash, slots := range storage {
-		// If the slots are nil, sanity check that it's a deleted account
-		if slots == nil {
-			// Ensure that the account was just marked as deleted
-			if account, ok := accounts[accountHash]; account != nil || !ok {
-				panic(fmt.Sprintf("storage in %#x nil, but account conflicts (%#x, exists: %v)", accountHash, account, ok))
-			}
-			// Everything ok, store the deletion mark and continue
-			dl.storageList[accountHash] = nil
-			continue
-		}
-		// Storage slots are not nil so entire contract was not deleted, ensure the
-		// account was just updated.
-		if account, ok := accounts[accountHash]; account == nil || !ok {
-			log.Error(fmt.Sprintf("storage in %#x exists, but account nil (exists: %v)", accountHash, ok))
-		}
-		// Determine memory size and track the dirty writes
+	for accountHash := range destructs {
+		dl.storageList[accountHash] = nil
+	}
+	// Determine memory size and track the dirty writes
+	for _, slots := range storage {
 		for _, data := range slots {
 			dl.memory += uint64(common.HashLength + len(data))
 			snapshotDirtyStorageWriteMeter.Mark(int64(len(data)))
@@ -208,6 +232,9 @@ func (dl *diffLayer) rebloom(origin *diskLayer) {
 		dl.diffed, _ = bloomfilter.New(uint64(bloomSize), uint64(bloomFuncs))
 	}
 	// Iterate over all the accounts and storage slots and index them
+	for hash := range dl.destructSet {
+		dl.diffed.Add(destructBloomHasher(hash))
+	}
 	for hash := range dl.accountData {
 		dl.diffed.Add(accountBloomHasher(hash))
 	}
@@ -265,6 +292,9 @@ func (dl *diffLayer) AccountRLP(hash common.Hash) ([]byte, error) {
 	// all the maps in all the layers below
 	dl.lock.RLock()
 	hit := dl.diffed.Contains(accountBloomHasher(hash))
+	if !hit {
+		hit = dl.diffed.Contains(destructBloomHasher(hash))
+	}
 	dl.lock.RUnlock()
 
 	// If the bloom filter misses, don't even bother with traversing the memory
@@ -289,19 +319,22 @@ func (dl *diffLayer) accountRLP(hash common.Hash, depth int) ([]byte, error) {
 	if dl.Stale() {
 		return nil, ErrSnapshotStale
 	}
-	// If the account is known locally, return it. Note, a nil account means it was
-	// deleted, and is a different notion than an unknown account!
+	// If the account is known locally, return it
 	if data, ok := dl.accountData[hash]; ok {
 		snapshotDirtyAccountHitMeter.Mark(1)
 		snapshotDirtyAccountHitDepthHist.Update(int64(depth))
-		if n := len(data); n > 0 {
-			snapshotDirtyAccountReadMeter.Mark(int64(n))
-		} else {
-			snapshotDirtyAccountInexMeter.Mark(1)
-		}
+		snapshotDirtyAccountReadMeter.Mark(int64(len(data)))
 		snapshotBloomAccountTrueHitMeter.Mark(1)
 		return data, nil
 	}
+	// If the account is known locally, but deleted, return it
+	if _, ok := dl.destructSet[hash]; ok {
+		snapshotDirtyAccountHitMeter.Mark(1)
+		snapshotDirtyAccountHitDepthHist.Update(int64(depth))
+		snapshotDirtyAccountInexMeter.Mark(1)
+		snapshotBloomAccountTrueHitMeter.Mark(1)
+		return nil, nil
+	}
 	// Account unknown to this diff, resolve from parent
 	if diff, ok := dl.parent.(*diffLayer); ok {
 		return diff.accountRLP(hash, depth+1)
@@ -319,6 +352,9 @@ func (dl *diffLayer) Storage(accountHash, storageHash common.Hash) ([]byte, erro
 	// all the maps in all the layers below
 	dl.lock.RLock()
 	hit := dl.diffed.Contains(storageBloomHasher{accountHash, storageHash})
+	if !hit {
+		hit = dl.diffed.Contains(destructBloomHasher(accountHash))
+	}
 	dl.lock.RUnlock()
 
 	// If the bloom filter misses, don't even bother with traversing the memory
@@ -343,16 +379,8 @@ func (dl *diffLayer) storage(accountHash, storageHash common.Hash, depth int) ([
 	if dl.Stale() {
 		return nil, ErrSnapshotStale
 	}
-	// If the account is known locally, try to resolve the slot locally. Note, a nil
-	// account means it was deleted, and is a different notion than an unknown account!
+	// If the account is known locally, try to resolve the slot locally
 	if storage, ok := dl.storageData[accountHash]; ok {
-		if storage == nil {
-			snapshotDirtyStorageHitMeter.Mark(1)
-			snapshotDirtyStorageHitDepthHist.Update(int64(depth))
-			snapshotDirtyStorageInexMeter.Mark(1)
-			snapshotBloomStorageTrueHitMeter.Mark(1)
-			return nil, nil
-		}
 		if data, ok := storage[storageHash]; ok {
 			snapshotDirtyStorageHitMeter.Mark(1)
 			snapshotDirtyStorageHitDepthHist.Update(int64(depth))
@@ -365,6 +393,14 @@ func (dl *diffLayer) storage(accountHash, storageHash common.Hash, depth int) ([
 			return data, nil
 		}
 	}
+	// If the account is known locally, but deleted, return an empty slot
+	if _, ok := dl.destructSet[accountHash]; ok {
+		snapshotDirtyStorageHitMeter.Mark(1)
+		snapshotDirtyStorageHitDepthHist.Update(int64(depth))
+		snapshotDirtyStorageInexMeter.Mark(1)
+		snapshotBloomStorageTrueHitMeter.Mark(1)
+		return nil, nil
+	}
 	// Storage slot unknown to this diff, resolve from parent
 	if diff, ok := dl.parent.(*diffLayer); ok {
 		return diff.storage(accountHash, storageHash, depth+1)
@@ -376,8 +412,8 @@ func (dl *diffLayer) storage(accountHash, storageHash common.Hash, depth int) ([
 
 // Update creates a new layer on top of the existing snapshot diff tree with
 // the specified data items.
-func (dl *diffLayer) Update(blockRoot common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
-	return newDiffLayer(dl, blockRoot, accounts, storage)
+func (dl *diffLayer) Update(blockRoot common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
+	return newDiffLayer(dl, blockRoot, destructs, accounts, storage)
 }
 
 // flatten pushes all data from this point downwards, flattening everything into
@@ -403,14 +439,18 @@ func (dl *diffLayer) flatten() snapshot {
 		panic("parent diff layer is stale") // we've flattened into the same parent from two children, boo
 	}
 	// Overwrite all the updated accounts blindly, merge the sorted list
+	for hash := range dl.destructSet {
+		parent.destructSet[hash] = struct{}{}
+		delete(parent.accountData, hash)
+		delete(parent.storageData, hash)
+	}
 	for hash, data := range dl.accountData {
 		parent.accountData[hash] = data
 	}
 	// Overwrite all the updated storage slots (individually)
 	for accountHash, storage := range dl.storageData {
-		// If storage didn't exist (or was deleted) in the parent; or if the storage
-		// was freshly deleted in the child, overwrite blindly
-		if parent.storageData[accountHash] == nil || storage == nil {
+		// If storage didn't exist (or was deleted) in the parent, overwrite blindly
+		if _, ok := parent.storageData[accountHash]; !ok {
 			parent.storageData[accountHash] = storage
 			continue
 		}
@@ -426,6 +466,7 @@ func (dl *diffLayer) flatten() snapshot {
 		parent:      parent.parent,
 		origin:      parent.origin,
 		root:        dl.root,
+		destructSet: parent.destructSet,
 		accountData: parent.accountData,
 		storageData: parent.storageData,
 		storageList: make(map[common.Hash][]common.Hash),
@@ -451,7 +492,10 @@ func (dl *diffLayer) AccountList() []common.Hash {
 	dl.lock.Lock()
 	defer dl.lock.Unlock()
 
-	dl.accountList = make([]common.Hash, 0, len(dl.accountData))
+	dl.accountList = make([]common.Hash, 0, len(dl.destructSet)+len(dl.accountData))
+	for hash := range dl.destructSet {
+		dl.accountList = append(dl.accountList, hash)
+	}
 	for hash := range dl.accountData {
 		dl.accountList = append(dl.accountList, hash)
 	}

core/state/snapshot/difflayer_test.go

@@ -30,8 +30,9 @@ import (
 // TestMergeBasics tests some simple merges
 func TestMergeBasics(t *testing.T) {
 	var (
-		accounts = make(map[common.Hash][]byte)
-		storage  = make(map[common.Hash]map[common.Hash][]byte)
+		destructs = make(map[common.Hash]struct{})
+		accounts  = make(map[common.Hash][]byte)
+		storage   = make(map[common.Hash]map[common.Hash][]byte)
 	)
 	// Fill up a parent
 	for i := 0; i < 100; i++ {
@@ -39,7 +40,10 @@ func TestMergeBasics(t *testing.T) {
 		data := randomAccount()
 
 		accounts[h] = data
-		if rand.Intn(20) < 10 {
+		if rand.Intn(4) == 0 {
+			destructs[h] = struct{}{}
+		}
+		if rand.Intn(2) == 0 {
 			accStorage := make(map[common.Hash][]byte)
 			value := make([]byte, 32)
 			rand.Read(value)
@@ -48,20 +52,18 @@ func TestMergeBasics(t *testing.T) {
 		}
 	}
 	// Add some (identical) layers on top
-	parent := newDiffLayer(emptyLayer(), common.Hash{}, accounts, storage)
-	child := newDiffLayer(parent, common.Hash{}, accounts, storage)
-	child = newDiffLayer(child, common.Hash{}, accounts, storage)
-	child = newDiffLayer(child, common.Hash{}, accounts, storage)
-	child = newDiffLayer(child, common.Hash{}, accounts, storage)
+	parent := newDiffLayer(emptyLayer(), common.Hash{}, destructs, accounts, storage)
+	child := newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
+	child = newDiffLayer(child, common.Hash{}, destructs, accounts, storage)
+	child = newDiffLayer(child, common.Hash{}, destructs, accounts, storage)
+	child = newDiffLayer(child, common.Hash{}, destructs, accounts, storage)
 	// And flatten
 	merged := (child.flatten()).(*diffLayer)
 
 	{ // Check account lists
-		// Should be zero/nil first
 		if got, exp := len(merged.accountList), 0; got != exp {
 			t.Errorf("accountList wrong, got %v exp %v", got, exp)
 		}
-		// Then set when we call AccountList
 		if got, exp := len(merged.AccountList()), len(accounts); got != exp {
 			t.Errorf("AccountList() wrong, got %v exp %v", got, exp)
 		}
@@ -69,6 +71,11 @@ func TestMergeBasics(t *testing.T) {
 			t.Errorf("accountList [2] wrong, got %v exp %v", got, exp)
 		}
 	}
+	{ // Check account drops
+		if got, exp := len(merged.destructSet), len(destructs); got != exp {
+			t.Errorf("accountDrop wrong, got %v exp %v", got, exp)
+		}
+	}
 	{ // Check storage lists
 		i := 0
 		for aHash, sMap := range storage {
@@ -95,42 +102,61 @@ func TestMergeDelete(t *testing.T) {
 	h1 := common.HexToHash("0x01")
 	h2 := common.HexToHash("0x02")
 
-	flip := func() map[common.Hash][]byte {
-		accs := make(map[common.Hash][]byte)
-		accs[h1] = randomAccount()
-		accs[h2] = nil
-		return accs
+	flipDrops := func() map[common.Hash]struct{} {
+		return map[common.Hash]struct{}{
+			h2: struct{}{},
+		}
+	}
+	flipAccs := func() map[common.Hash][]byte {
+		return map[common.Hash][]byte{
+			h1: randomAccount(),
+		}
 	}
-	flop := func() map[common.Hash][]byte {
-		accs := make(map[common.Hash][]byte)
-		accs[h1] = nil
-		accs[h2] = randomAccount()
-		return accs
+	flopDrops := func() map[common.Hash]struct{} {
+		return map[common.Hash]struct{}{
+			h1: struct{}{},
+		}
 	}
-
-	// Add some flip-flopping layers on top
-	parent := newDiffLayer(emptyLayer(), common.Hash{}, flip(), storage)
-	child := parent.Update(common.Hash{}, flop(), storage)
-	child = child.Update(common.Hash{}, flip(), storage)
-	child = child.Update(common.Hash{}, flop(), storage)
-	child = child.Update(common.Hash{}, flip(), storage)
-	child = child.Update(common.Hash{}, flop(), storage)
-	child = child.Update(common.Hash{}, flip(), storage)
+	flopAccs := func() map[common.Hash][]byte {
+		return map[common.Hash][]byte{
+			h2: randomAccount(),
+		}
+	}
+	// Add some flipAccs-flopping layers on top
+	parent := newDiffLayer(emptyLayer(), common.Hash{}, flipDrops(), flipAccs(), storage)
+	child := parent.Update(common.Hash{}, flopDrops(), flopAccs(), storage)
+	child = child.Update(common.Hash{}, flipDrops(), flipAccs(), storage)
+	child = child.Update(common.Hash{}, flopDrops(), flopAccs(), storage)
+	child = child.Update(common.Hash{}, flipDrops(), flipAccs(), storage)
+	child = child.Update(common.Hash{}, flopDrops(), flopAccs(), storage)
+	child = child.Update(common.Hash{}, flipDrops(), flipAccs(), storage)
 
 	if data, _ := child.Account(h1); data == nil {
-		t.Errorf("last diff layer: expected %x to be non-nil", h1)
+		t.Errorf("last diff layer: expected %x account to be non-nil", h1)
 	}
 	if data, _ := child.Account(h2); data != nil {
-		t.Errorf("last diff layer: expected %x to be nil", h2)
+		t.Errorf("last diff layer: expected %x account to be nil", h2)
+	}
+	if _, ok := child.destructSet[h1]; ok {
+		t.Errorf("last diff layer: expected %x drop to be missing", h1)
+	}
+	if _, ok := child.destructSet[h2]; !ok {
+		t.Errorf("last diff layer: expected %x drop to be present", h1)
 	}
 	// And flatten
 	merged := (child.flatten()).(*diffLayer)
 
 	if data, _ := merged.Account(h1); data == nil {
-		t.Errorf("merged layer: expected %x to be non-nil", h1)
+		t.Errorf("merged layer: expected %x account to be non-nil", h1)
 	}
 	if data, _ := merged.Account(h2); data != nil {
-		t.Errorf("merged layer: expected %x to be nil", h2)
+		t.Errorf("merged layer: expected %x account to be nil", h2)
+	}
+	if _, ok := merged.destructSet[h1]; !ok { // Note, drops stay alive until persisted to disk!
+		t.Errorf("merged diff layer: expected %x drop to be present", h1)
+	}
+	if _, ok := merged.destructSet[h2]; !ok { // Note, drops stay alive until persisted to disk!
+		t.Errorf("merged diff layer: expected %x drop to be present", h1)
 	}
 	// If we add more granular metering of memory, we can enable this again,
 	// but it's not implemented for now
@@ -150,18 +176,23 @@ func TestInsertAndMerge(t *testing.T) {
 		child  *diffLayer
 	)
 	{
-		var accounts = make(map[common.Hash][]byte)
-		var storage = make(map[common.Hash]map[common.Hash][]byte)
-		parent = newDiffLayer(emptyLayer(), common.Hash{}, accounts, storage)
+		var (
+			destructs = make(map[common.Hash]struct{})
+			accounts  = make(map[common.Hash][]byte)
+			storage   = make(map[common.Hash]map[common.Hash][]byte)
+		)
+		parent = newDiffLayer(emptyLayer(), common.Hash{}, destructs, accounts, storage)
 	}
 	{
-		var accounts = make(map[common.Hash][]byte)
-		var storage = make(map[common.Hash]map[common.Hash][]byte)
+		var (
+			destructs = make(map[common.Hash]struct{})
+			accounts  = make(map[common.Hash][]byte)
+			storage   = make(map[common.Hash]map[common.Hash][]byte)
+		)
 		accounts[acc] = randomAccount()
-		accstorage := make(map[common.Hash][]byte)
-		storage[acc] = accstorage
+		storage[acc] = make(map[common.Hash][]byte)
 		storage[acc][slot] = []byte{0x01}
-		child = newDiffLayer(parent, common.Hash{}, accounts, storage)
+		child = newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
 	}
 	// And flatten
 	merged := (child.flatten()).(*diffLayer)
@@ -189,20 +220,21 @@ func emptyLayer() *diskLayer {
 func BenchmarkSearch(b *testing.B) {
 	// First, we set up 128 diff layers, with 1K items each
 	fill := func(parent snapshot) *diffLayer {
-		accounts := make(map[common.Hash][]byte)
-		storage := make(map[common.Hash]map[common.Hash][]byte)
-
+		var (
+			destructs = make(map[common.Hash]struct{})
+			accounts  = make(map[common.Hash][]byte)
+			storage   = make(map[common.Hash]map[common.Hash][]byte)
+		)
 		for i := 0; i < 10000; i++ {
 			accounts[randomHash()] = randomAccount()
 		}
-		return newDiffLayer(parent, common.Hash{}, accounts, storage)
+		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
 	}
 	var layer snapshot
 	layer = emptyLayer()
 	for i := 0; i < 128; i++ {
 		layer = fill(layer)
 	}
-
 	key := crypto.Keccak256Hash([]byte{0x13, 0x38})
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -224,9 +256,12 @@ func BenchmarkSearchSlot(b *testing.B) {
 	storageKey := crypto.Keccak256Hash([]byte{0x13, 0x37})
 	accountRLP := randomAccount()
 	fill := func(parent snapshot) *diffLayer {
-		accounts := make(map[common.Hash][]byte)
+		var (
+			destructs = make(map[common.Hash]struct{})
+			accounts  = make(map[common.Hash][]byte)
+			storage   = make(map[common.Hash]map[common.Hash][]byte)
+		)
 		accounts[accountKey] = accountRLP
-		storage := make(map[common.Hash]map[common.Hash][]byte)
 
 		accStorage := make(map[common.Hash][]byte)
 		for i := 0; i < 5; i++ {
@@ -235,7 +270,7 @@ func BenchmarkSearchSlot(b *testing.B) {
 			accStorage[randomHash()] = value
 			storage[accountKey] = accStorage
 		}
-		return newDiffLayer(parent, common.Hash{}, accounts, storage)
+		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
 	}
 	var layer snapshot
 	layer = emptyLayer()
@@ -249,15 +284,17 @@ func BenchmarkSearchSlot(b *testing.B) {
 }
 
 // With accountList and sorting
-//BenchmarkFlatten-6   	      50	  29890856 ns/op
+// BenchmarkFlatten-6   	      50	  29890856 ns/op
 //
 // Without sorting and tracking accountlist
 // BenchmarkFlatten-6   	     300	   5511511 ns/op
 func BenchmarkFlatten(b *testing.B) {
 	fill := func(parent snapshot) *diffLayer {
-		accounts := make(map[common.Hash][]byte)
-		storage := make(map[common.Hash]map[common.Hash][]byte)
-
+		var (
+			destructs = make(map[common.Hash]struct{})
+			accounts  = make(map[common.Hash][]byte)
+			storage   = make(map[common.Hash]map[common.Hash][]byte)
+		)
 		for i := 0; i < 100; i++ {
 			accountKey := randomHash()
 			accounts[accountKey] = randomAccount()
@@ -271,11 +308,9 @@ func BenchmarkFlatten(b *testing.B) {
 			}
 			storage[accountKey] = accStorage
 		}
-		return newDiffLayer(parent, common.Hash{}, accounts, storage)
+		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
 	}
-
 	b.ResetTimer()
-
 	for i := 0; i < b.N; i++ {
 		b.StopTimer()
 		var layer snapshot
@@ -305,9 +340,11 @@ func BenchmarkFlatten(b *testing.B) {
 // BenchmarkJournal-6   	       1	1208083335 ns/op // bufio writer
 func BenchmarkJournal(b *testing.B) {
 	fill := func(parent snapshot) *diffLayer {
-		accounts := make(map[common.Hash][]byte)
-		storage := make(map[common.Hash]map[common.Hash][]byte)
-
+		var (
+			destructs = make(map[common.Hash]struct{})
+			accounts  = make(map[common.Hash][]byte)
+			storage   = make(map[common.Hash]map[common.Hash][]byte)
+		)
 		for i := 0; i < 200; i++ {
 			accountKey := randomHash()
 			accounts[accountKey] = randomAccount()
@@ -321,7 +358,7 @@ func BenchmarkJournal(b *testing.B) {
 			}
 			storage[accountKey] = accStorage
 		}
-		return newDiffLayer(parent, common.Hash{}, accounts, storage)
+		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
 	}
 	layer := snapshot(new(diskLayer))
 	for i := 1; i < 128; i++ {

core/state/snapshot/disklayer.go

@@ -161,6 +161,6 @@ func (dl *diskLayer) Storage(accountHash, storageHash common.Hash) ([]byte, erro
 // Update creates a new layer on top of the existing snapshot diff tree with
 // the specified data items. Note, the maps are retained by the method to avoid
 // copying everything.
-func (dl *diskLayer) Update(blockHash common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
-	return newDiffLayer(dl, blockHash, accounts, storage)
+func (dl *diskLayer) Update(blockHash common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
+	return newDiffLayer(dl, blockHash, destructs, accounts, storage)
 }

core/state/snapshot/disklayer_test.go

@@ -116,13 +116,14 @@ func TestDiskMerge(t *testing.T) {
 	base.Storage(conNukeCache, conNukeCacheSlot)
 
 	// Modify or delete some accounts, flatten everything onto disk
-	if err := snaps.Update(diffRoot, baseRoot, map[common.Hash][]byte{
-		accModNoCache:  reverse(accModNoCache[:]),
-		accModCache:    reverse(accModCache[:]),
-		accDelNoCache:  nil,
-		accDelCache:    nil,
-		conNukeNoCache: nil,
-		conNukeCache:   nil,
+	if err := snaps.Update(diffRoot, baseRoot, map[common.Hash]struct{}{
+		accDelNoCache:  struct{}{},
+		accDelCache:    struct{}{},
+		conNukeNoCache: struct{}{},
+		conNukeCache:   struct{}{},
+	}, map[common.Hash][]byte{
+		accModNoCache: reverse(accModNoCache[:]),
+		accModCache:   reverse(accModCache[:]),
 	}, map[common.Hash]map[common.Hash][]byte{
 		conModNoCache: {conModNoCacheSlot: reverse(conModNoCacheSlot[:])},
 		conModCache:   {conModCacheSlot: reverse(conModCacheSlot[:])},
@@ -338,13 +339,14 @@ func TestDiskPartialMerge(t *testing.T) {
 		assertStorage(conNukeCache, conNukeCacheSlot, conNukeCacheSlot[:])
 
 		// Modify or delete some accounts, flatten everything onto disk
-		if err := snaps.Update(diffRoot, baseRoot, map[common.Hash][]byte{
-			accModNoCache:  reverse(accModNoCache[:]),
-			accModCache:    reverse(accModCache[:]),
-			accDelNoCache:  nil,
-			accDelCache:    nil,
-			conNukeNoCache: nil,
-			conNukeCache:   nil,
+		if err := snaps.Update(diffRoot, baseRoot, map[common.Hash]struct{}{
+			accDelNoCache:  struct{}{},
+			accDelCache:    struct{}{},
+			conNukeNoCache: struct{}{},
+			conNukeCache:   struct{}{},
+		}, map[common.Hash][]byte{
+			accModNoCache: reverse(accModNoCache[:]),
+			accModCache:   reverse(accModCache[:]),
 		}, map[common.Hash]map[common.Hash][]byte{
 			conModNoCache: {conModNoCacheSlot: reverse(conModNoCacheSlot[:])},
 			conModCache:   {conModCacheSlot: reverse(conModCacheSlot[:])},

core/state/snapshot/iterator_test.go

@@ -28,18 +28,23 @@ import (
 	"github.com/ethereum/go-ethereum/core/rawdb"
 )
 
-// TestIteratorBasics tests some simple single-layer iteration
-func TestIteratorBasics(t *testing.T) {
+// TestAccountIteratorBasics tests some simple single-layer iteration
+func TestAccountIteratorBasics(t *testing.T) {
 	var (
-		accounts = make(map[common.Hash][]byte)
-		storage  = make(map[common.Hash]map[common.Hash][]byte)
+		destructs = make(map[common.Hash]struct{})
+		accounts  = make(map[common.Hash][]byte)
+		storage   = make(map[common.Hash]map[common.Hash][]byte)
 	)
 	// Fill up a parent
 	for i := 0; i < 100; i++ {
 		h := randomHash()
 		data := randomAccount()
+
 		accounts[h] = data
-		if rand.Intn(20) < 10 {
+		if rand.Intn(4) == 0 {
+			destructs[h] = struct{}{}
+		}
+		if rand.Intn(2) == 0 {
 			accStorage := make(map[common.Hash][]byte)
 			value := make([]byte, 32)
 			rand.Read(value)
@@ -48,7 +53,7 @@ func TestIteratorBasics(t *testing.T) {
 		}
 	}
 	// Add some (identical) layers on top
-	parent := newDiffLayer(emptyLayer(), common.Hash{}, accounts, storage)
+	parent := newDiffLayer(emptyLayer(), common.Hash{}, destructs, accounts, storage)
 	it := parent.AccountIterator(common.Hash{})
 	verifyIterator(t, 100, it)
 }
@@ -138,8 +143,8 @@ func verifyIterator(t *testing.T, expCount int, it AccountIterator) {
 	}
 }
 
-// TestIteratorTraversal tests some simple multi-layer iteration.
-func TestIteratorTraversal(t *testing.T) {
+// TestAccountIteratorTraversal tests some simple multi-layer iteration.
+func TestAccountIteratorTraversal(t *testing.T) {
 	// Create an empty base layer and a snapshot tree out of it
 	base := &diskLayer{
 		diskdb: rawdb.NewMemoryDatabase(),
@@ -152,13 +157,13 @@ func TestIteratorTraversal(t *testing.T) {
 		},
 	}
 	// Stack three diff layers on top with various overlaps
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"),
+	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
 		randomAccountSet("0xaa", "0xee", "0xff", "0xf0"), nil)
 
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"),
+	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
 		randomAccountSet("0xbb", "0xdd", "0xf0"), nil)
 
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"),
+	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
 		randomAccountSet("0xcc", "0xf0", "0xff"), nil)
 
 	// Verify the single and multi-layer iterators
@@ -173,9 +178,9 @@ func TestIteratorTraversal(t *testing.T) {
 	verifyIterator(t, 7, it)
 }
 
-// TestIteratorTraversalValues tests some multi-layer iteration, where we
+// TestAccountIteratorTraversalValues tests some multi-layer iteration, where we
 // also expect the correct values to show up.
-func TestIteratorTraversalValues(t *testing.T) {
+func TestAccountIteratorTraversalValues(t *testing.T) {
 	// Create an empty base layer and a snapshot tree out of it
 	base := &diskLayer{
 		diskdb: rawdb.NewMemoryDatabase(),
@@ -223,14 +228,14 @@ func TestIteratorTraversalValues(t *testing.T) {
 		}
 	}
 	// Assemble a stack of snapshots from the account layers
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), a, nil)
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), b, nil)
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), c, nil)
-	snaps.Update(common.HexToHash("0x05"), common.HexToHash("0x04"), d, nil)
-	snaps.Update(common.HexToHash("0x06"), common.HexToHash("0x05"), e, nil)
-	snaps.Update(common.HexToHash("0x07"), common.HexToHash("0x06"), f, nil)
-	snaps.Update(common.HexToHash("0x08"), common.HexToHash("0x07"), g, nil)
-	snaps.Update(common.HexToHash("0x09"), common.HexToHash("0x08"), h, nil)
+	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, a, nil)
+	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, b, nil)
+	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil, c, nil)
+	snaps.Update(common.HexToHash("0x05"), common.HexToHash("0x04"), nil, d, nil)
+	snaps.Update(common.HexToHash("0x06"), common.HexToHash("0x05"), nil, e, nil)
+	snaps.Update(common.HexToHash("0x07"), common.HexToHash("0x06"), nil, f, nil)
+	snaps.Update(common.HexToHash("0x08"), common.HexToHash("0x07"), nil, g, nil)
+	snaps.Update(common.HexToHash("0x09"), common.HexToHash("0x08"), nil, h, nil)
 
 	it, _ := snaps.AccountIterator(common.HexToHash("0x09"), common.Hash{})
 	defer it.Release()
@@ -249,7 +254,7 @@ func TestIteratorTraversalValues(t *testing.T) {
 }
 
 // This testcase is notorious, all layers contain the exact same 200 accounts.
-func TestIteratorLargeTraversal(t *testing.T) {
+func TestAccountIteratorLargeTraversal(t *testing.T) {
 	// Create a custom account factory to recreate the same addresses
 	makeAccounts := func(num int) map[common.Hash][]byte {
 		accounts := make(map[common.Hash][]byte)
@@ -272,7 +277,7 @@ func TestIteratorLargeTraversal(t *testing.T) {
 		},
 	}
 	for i := 1; i < 128; i++ {
-		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), makeAccounts(200), nil)
+		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), nil, makeAccounts(200), nil)
 	}
 	// Iterate the entire stack and ensure everything is hit only once
 	head := snaps.Snapshot(common.HexToHash("0x80"))
@@ -285,11 +290,11 @@ func TestIteratorLargeTraversal(t *testing.T) {
 	verifyIterator(t, 200, it)
 }
 
-// TestIteratorFlattening tests what happens when we
+// TestAccountIteratorFlattening tests what happens when we
 // - have a live iterator on child C (parent C1 -> C2 .. CN)
 // - flattens C2 all the way into CN
 // - continues iterating
-func TestIteratorFlattening(t *testing.T) {
+func TestAccountIteratorFlattening(t *testing.T) {
 	// Create an empty base layer and a snapshot tree out of it
 	base := &diskLayer{
 		diskdb: rawdb.NewMemoryDatabase(),
@@ -302,13 +307,13 @@ func TestIteratorFlattening(t *testing.T) {
 		},
 	}
 	// Create a stack of diffs on top
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"),
+	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
 		randomAccountSet("0xaa", "0xee", "0xff", "0xf0"), nil)
 
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"),
+	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
 		randomAccountSet("0xbb", "0xdd", "0xf0"), nil)
 
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"),
+	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
 		randomAccountSet("0xcc", "0xf0", "0xff"), nil)
 
 	// Create an iterator and flatten the data from underneath it
@@ -321,7 +326,7 @@ func TestIteratorFlattening(t *testing.T) {
 	//verifyIterator(t, 7, it)
 }
 
-func TestIteratorSeek(t *testing.T) {
+func TestAccountIteratorSeek(t *testing.T) {
 	// Create a snapshot stack with some initial data
 	base := &diskLayer{
 		diskdb: rawdb.NewMemoryDatabase(),
@@ -333,13 +338,13 @@ func TestIteratorSeek(t *testing.T) {
 			base.root: base,
 		},
 	}
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"),
+	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
 		randomAccountSet("0xaa", "0xee", "0xff", "0xf0"), nil)
 
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"),
+	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
 		randomAccountSet("0xbb", "0xdd", "0xf0"), nil)
 
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"),
+	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
 		randomAccountSet("0xcc", "0xf0", "0xff"), nil)
 
 	// Construct various iterators and ensure their tranversal is correct
@@ -372,18 +377,18 @@ func TestIteratorSeek(t *testing.T) {
 	verifyIterator(t, 0, it) // expected: nothing
 }
 
-// BenchmarkIteratorTraversal is a bit a bit notorious -- all layers contain the
+// BenchmarkAccountIteratorTraversal is a bit a bit notorious -- all layers contain the
 // exact same 200 accounts. That means that we need to process 2000 items, but
 // only spit out 200 values eventually.
 //
 // The value-fetching benchmark is easy on the binary iterator, since it never has to reach
 // down at any depth for retrieving the values -- all are on the toppmost layer
 //
-// BenchmarkIteratorTraversal/binary_iterator_keys-6         	    2239	    483674 ns/op
-// BenchmarkIteratorTraversal/binary_iterator_values-6       	    2403	    501810 ns/op
-// BenchmarkIteratorTraversal/fast_iterator_keys-6           	    1923	    677966 ns/op
-// BenchmarkIteratorTraversal/fast_iterator_values-6         	    1741	    649967 ns/op
-func BenchmarkIteratorTraversal(b *testing.B) {
+// BenchmarkAccountIteratorTraversal/binary_iterator_keys-6         	    2239	    483674 ns/op
+// BenchmarkAccountIteratorTraversal/binary_iterator_values-6       	    2403	    501810 ns/op
+// BenchmarkAccountIteratorTraversal/fast_iterator_keys-6           	    1923	    677966 ns/op
+// BenchmarkAccountIteratorTraversal/fast_iterator_values-6         	    1741	    649967 ns/op
+func BenchmarkAccountIteratorTraversal(b *testing.B) {
 	// Create a custom account factory to recreate the same addresses
 	makeAccounts := func(num int) map[common.Hash][]byte {
 		accounts := make(map[common.Hash][]byte)
@@ -406,7 +411,7 @@ func BenchmarkIteratorTraversal(b *testing.B) {
 		},
 	}
 	for i := 1; i <= 100; i++ {
-		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), makeAccounts(200), nil)
+		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), nil, makeAccounts(200), nil)
 	}
 	// We call this once before the benchmark, so the creation of
 	// sorted accountlists are not included in the results.
@@ -469,17 +474,17 @@ func BenchmarkIteratorTraversal(b *testing.B) {
 	})
 }
 
-// BenchmarkIteratorLargeBaselayer is a pretty realistic benchmark, where
+// BenchmarkAccountIteratorLargeBaselayer is a pretty realistic benchmark, where
 // the baselayer is a lot larger than the upper layer.
 //
 // This is heavy on the binary iterator, which in most cases will have to
 // call recursively 100 times for the majority of the values
 //
-// BenchmarkIteratorLargeBaselayer/binary_iterator_(keys)-6         	     514	   1971999 ns/op
-// BenchmarkIteratorLargeBaselayer/binary_iterator_(values)-6       	      61	  18997492 ns/op
-// BenchmarkIteratorLargeBaselayer/fast_iterator_(keys)-6           	   10000	    114385 ns/op
-// BenchmarkIteratorLargeBaselayer/fast_iterator_(values)-6         	    4047	    296823 ns/op
-func BenchmarkIteratorLargeBaselayer(b *testing.B) {
+// BenchmarkAccountIteratorLargeBaselayer/binary_iterator_(keys)-6         	     514	   1971999 ns/op
+// BenchmarkAccountIteratorLargeBaselayer/binary_iterator_(values)-6       	      61	  18997492 ns/op
+// BenchmarkAccountIteratorLargeBaselayer/fast_iterator_(keys)-6           	   10000	    114385 ns/op
+// BenchmarkAccountIteratorLargeBaselayer/fast_iterator_(values)-6         	    4047	    296823 ns/op
+func BenchmarkAccountIteratorLargeBaselayer(b *testing.B) {
 	// Create a custom account factory to recreate the same addresses
 	makeAccounts := func(num int) map[common.Hash][]byte {
 		accounts := make(map[common.Hash][]byte)
@@ -501,9 +506,9 @@ func BenchmarkIteratorLargeBaselayer(b *testing.B) {
 			base.root: base,
 		},
 	}
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), makeAccounts(2000), nil)
+	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, makeAccounts(2000), nil)
 	for i := 2; i <= 100; i++ {
-		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), makeAccounts(20), nil)
+		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), nil, makeAccounts(20), nil)
 	}
 	// We call this once before the benchmark, so the creation of
 	// sorted accountlists are not included in the results.
@@ -590,7 +595,7 @@ func benchmarkAccountIteration(b *testing.B, iterator func(snap snapshot) Accoun
 	}
 	stack := snapshot(emptyLayer())
 	for _, layer := range layers {
-		stack = stack.Update(common.Hash{}, layer, nil)
+		stack = stack.Update(common.Hash{}, layer, nil, nil)
 	}
 	// Reset the timers and report all the stats
 	it := iterator(stack)

core/state/snapshot/journal.go

@@ -43,6 +43,11 @@ type journalGenerator struct {
 	Storage  uint64
 }
 
+// journalDestruct is an account deletion entry in a diffLayer's disk journal.
+type journalDestruct struct {
+	Hash common.Hash
+}
+
 // journalAccount is an account entry in a diffLayer's disk journal.
 type journalAccount struct {
 	Hash common.Hash
@@ -139,6 +144,14 @@ func loadDiffLayer(parent snapshot, r *rlp.Stream) (snapshot, error) {
 		}
 		return nil, fmt.Errorf("load diff root: %v", err)
 	}
+	var destructs []journalDestruct
+	if err := r.Decode(&destructs); err != nil {
+		return nil, fmt.Errorf("load diff destructs: %v", err)
+	}
+	destructSet := make(map[common.Hash]struct{})
+	for _, entry := range destructs {
+		destructSet[entry.Hash] = struct{}{}
+	}
 	var accounts []journalAccount
 	if err := r.Decode(&accounts); err != nil {
 		return nil, fmt.Errorf("load diff accounts: %v", err)
@@ -159,7 +172,7 @@ func loadDiffLayer(parent snapshot, r *rlp.Stream) (snapshot, error) {
 		}
 		storageData[entry.Hash] = slots
 	}
-	return loadDiffLayer(newDiffLayer(parent, root, accountData, storageData), r)
+	return loadDiffLayer(newDiffLayer(parent, root, destructSet, accountData, storageData), r)
 }
 
 // Journal writes the persistent layer generator stats into a buffer to be stored
@@ -218,6 +231,13 @@ func (dl *diffLayer) Journal(buffer *bytes.Buffer) (common.Hash, error) {
 	if err := rlp.Encode(buffer, dl.root); err != nil {
 		return common.Hash{}, err
 	}
+	destructs := make([]journalDestruct, 0, len(dl.destructSet))
+	for hash := range dl.destructSet {
+		destructs = append(destructs, journalDestruct{Hash: hash})
+	}
+	if err := rlp.Encode(buffer, destructs); err != nil {
+		return common.Hash{}, err
+	}
 	accounts := make([]journalAccount, 0, len(dl.accountData))
 	for hash, blob := range dl.accountData {
 		accounts = append(accounts, journalAccount{Hash: hash, Blob: blob})

core/state/snapshot/snapshot.go

@@ -125,7 +125,7 @@ type snapshot interface {
 	// the specified data items.
 	//
 	// Note, the maps are retained by the method to avoid copying everything.
-	Update(blockRoot common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer
+	Update(blockRoot common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer
 
 	// Journal commits an entire diff hierarchy to disk into a single journal entry.
 	// This is meant to be used during shutdown to persist the snapshot without
@@ -222,7 +222,7 @@ func (t *Tree) Snapshot(blockRoot common.Hash) Snapshot {
 
 // Update adds a new snapshot into the tree, if that can be linked to an existing
 // old parent. It is disallowed to insert a disk layer (the origin of all).
-func (t *Tree) Update(blockRoot common.Hash, parentRoot common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) error {
+func (t *Tree) Update(blockRoot common.Hash, parentRoot common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) error {
 	// Reject noop updates to avoid self-loops in the snapshot tree. This is a
 	// special case that can only happen for Clique networks where empty blocks
 	// don't modify the state (0 block subsidy).
@@ -237,7 +237,7 @@ func (t *Tree) Update(blockRoot common.Hash, parentRoot common.Hash, accounts ma
 	if parent == nil {
 		return fmt.Errorf("parent [%#x] snapshot missing", parentRoot)
 	}
-	snap := parent.Update(blockRoot, accounts, storage)
+	snap := parent.Update(blockRoot, destructs, accounts, storage)
 
 	// Save the new snapshot for later
 	t.lock.Lock()
@@ -425,40 +425,43 @@ func diffToDisk(bottom *diffLayer) *diskLayer {
 	base.stale = true
 	base.lock.Unlock()
 
-	// Push all the accounts into the database
-	for hash, data := range bottom.accountData {
+	// Destroy all the destructed accounts from the database
+	for hash := range bottom.destructSet {
 		// Skip any account not covered yet by the snapshot
 		if base.genMarker != nil && bytes.Compare(hash[:], base.genMarker) > 0 {
 			continue
 		}
-		if len(data) > 0 {
-			// Account was updated, push to disk
-			rawdb.WriteAccountSnapshot(batch, hash, data)
-			base.cache.Set(hash[:], data)
-			snapshotCleanAccountWriteMeter.Mark(int64(len(data)))
-
-			if batch.ValueSize() > ethdb.IdealBatchSize {
-				if err := batch.Write(); err != nil {
-					log.Crit("Failed to write account snapshot", "err", err)
-				}
-				batch.Reset()
+		// Remove all storage slots
+		rawdb.DeleteAccountSnapshot(batch, hash)
+		base.cache.Set(hash[:], nil)
+
+		it := rawdb.IterateStorageSnapshots(base.diskdb, hash)
+		for it.Next() {
+			if key := it.Key(); len(key) == 65 { // TODO(karalabe): Yuck, we should move this into the iterator
+				batch.Delete(key)
+				base.cache.Del(key[1:])
+
+				snapshotFlushStorageItemMeter.Mark(1)
 			}
-		} else {
-			// Account was deleted, remove all storage slots too
-			rawdb.DeleteAccountSnapshot(batch, hash)
-			base.cache.Set(hash[:], nil)
-
-			it := rawdb.IterateStorageSnapshots(base.diskdb, hash)
-			for it.Next() {
-				if key := it.Key(); len(key) == 65 { // TODO(karalabe): Yuck, we should move this into the iterator
-					batch.Delete(key)
-					base.cache.Del(key[1:])
-
-					snapshotFlushStorageItemMeter.Mark(1)
-					snapshotFlushStorageSizeMeter.Mark(int64(len(data)))
-				}
+		}
+		it.Release()
+	}
+	// Push all updated accounts into the database
+	for hash, data := range bottom.accountData {
+		// Skip any account not covered yet by the snapshot
+		if base.genMarker != nil && bytes.Compare(hash[:], base.genMarker) > 0 {
+			continue
+		}
+		// Push the account to disk
+		rawdb.WriteAccountSnapshot(batch, hash, data)
+		base.cache.Set(hash[:], data)
+		snapshotCleanAccountWriteMeter.Mark(int64(len(data)))
+
+		if batch.ValueSize() > ethdb.IdealBatchSize {
+			if err := batch.Write(); err != nil {
+				log.Crit("Failed to write account snapshot", "err", err)
 			}
-			it.Release()
+			batch.Reset()
 		}
 		snapshotFlushAccountItemMeter.Mark(1)
 		snapshotFlushAccountSizeMeter.Mark(int64(len(data)))

core/state/snapshot/snapshot_test.go

@@ -81,7 +81,7 @@ func TestDiskLayerExternalInvalidationFullFlatten(t *testing.T) {
 	accounts := map[common.Hash][]byte{
 		common.HexToHash("0xa1"): randomAccount(),
 	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
 	if n := len(snaps.layers); n != 2 {
@@ -91,7 +91,7 @@ func TestDiskLayerExternalInvalidationFullFlatten(t *testing.T) {
 	if err := snaps.Cap(common.HexToHash("0x02"), 0); err != nil {
 		t.Fatalf("failed to merge diff layer onto disk: %v", err)
 	}
-	// Since the base layer was modified, ensure that data retrievald on the external reference fail
+	// Since the base layer was modified, ensure that data retrieval on the external reference fail
 	if acc, err := ref.Account(common.HexToHash("0x01")); err != ErrSnapshotStale {
 		t.Errorf("stale reference returned account: %#x (err: %v)", acc, err)
 	}
@@ -125,10 +125,10 @@ func TestDiskLayerExternalInvalidationPartialFlatten(t *testing.T) {
 	accounts := map[common.Hash][]byte{
 		common.HexToHash("0xa1"): randomAccount(),
 	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
-	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
 	if n := len(snaps.layers); n != 3 {
@@ -173,10 +173,10 @@ func TestDiffLayerExternalInvalidationFullFlatten(t *testing.T) {
 	accounts := map[common.Hash][]byte{
 		common.HexToHash("0xa1"): randomAccount(),
 	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
-	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
 	if n := len(snaps.layers); n != 3 {
@@ -220,13 +220,13 @@ func TestDiffLayerExternalInvalidationPartialFlatten(t *testing.T) {
 	accounts := map[common.Hash][]byte{
 		common.HexToHash("0xa1"): randomAccount(),
 	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
-	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
-	if err := snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), accounts, nil); err != nil {
+	if err := snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil, accounts, nil); err != nil {
 		t.Fatalf("failed to create a diff layer: %v", err)
 	}
 	if n := len(snaps.layers); n != 4 {
@@ -280,12 +280,12 @@ func TestPostCapBasicDataAccess(t *testing.T) {
 		},
 	}
 	// The lowest difflayer
-	snaps.Update(common.HexToHash("0xa1"), common.HexToHash("0x01"), setAccount("0xa1"), nil)
-	snaps.Update(common.HexToHash("0xa2"), common.HexToHash("0xa1"), setAccount("0xa2"), nil)
-	snaps.Update(common.HexToHash("0xb2"), common.HexToHash("0xa1"), setAccount("0xb2"), nil)
+	snaps.Update(common.HexToHash("0xa1"), common.HexToHash("0x01"), nil, setAccount("0xa1"), nil)
+	snaps.Update(common.HexToHash("0xa2"), common.HexToHash("0xa1"), nil, setAccount("0xa2"), nil)
+	snaps.Update(common.HexToHash("0xb2"), common.HexToHash("0xa1"), nil, setAccount("0xb2"), nil)
 
-	snaps.Update(common.HexToHash("0xa3"), common.HexToHash("0xa2"), setAccount("0xa3"), nil)
-	snaps.Update(common.HexToHash("0xb3"), common.HexToHash("0xb2"), setAccount("0xb3"), nil)
+	snaps.Update(common.HexToHash("0xa3"), common.HexToHash("0xa2"), nil, setAccount("0xa3"), nil)
+	snaps.Update(common.HexToHash("0xb3"), common.HexToHash("0xb2"), nil, setAccount("0xb3"), nil)
 
 	// checkExist verifies if an account exiss in a snapshot
 	checkExist := func(layer *diffLayer, key string) error {

core/state/statedb.go

@@ -67,10 +67,11 @@ type StateDB struct {
 	db   Database
 	trie Trie
 
-	snaps        *snapshot.Tree
-	snap         snapshot.Snapshot
-	snapAccounts map[common.Hash][]byte
-	snapStorage  map[common.Hash]map[common.Hash][]byte
+	snaps         *snapshot.Tree
+	snap          snapshot.Snapshot
+	snapDestructs map[common.Hash]struct{}
+	snapAccounts  map[common.Hash][]byte
+	snapStorage   map[common.Hash]map[common.Hash][]byte
 
 	// This map holds 'live' objects, which will get modified while processing a state transition.
 	stateObjects        map[common.Address]*stateObject
@@ -133,6 +134,7 @@ func New(root common.Hash, db Database, snaps *snapshot.Tree) (*StateDB, error)
 	}
 	if sdb.snaps != nil {
 		if sdb.snap = sdb.snaps.Snapshot(root); sdb.snap != nil {
+			sdb.snapDestructs = make(map[common.Hash]struct{})
 			sdb.snapAccounts = make(map[common.Hash][]byte)
 			sdb.snapStorage = make(map[common.Hash]map[common.Hash][]byte)
 		}
@@ -171,8 +173,9 @@ func (s *StateDB) Reset(root common.Hash) error {
 	s.clearJournalAndRefund()
 
 	if s.snaps != nil {
-		s.snapAccounts, s.snapStorage = nil, nil
+		s.snapAccounts, s.snapDestructs, s.snapStorage = nil, nil, nil
 		if s.snap = s.snaps.Snapshot(root); s.snap != nil {
+			s.snapDestructs = make(map[common.Hash]struct{})
 			s.snapAccounts = make(map[common.Hash][]byte)
 			s.snapStorage = make(map[common.Hash]map[common.Hash][]byte)
 		}
@@ -463,15 +466,6 @@ func (s *StateDB) updateStateObject(obj *stateObject) {
 		panic(fmt.Errorf("can't encode object at %x: %v", addr[:], err))
 	}
 	s.setError(s.trie.TryUpdate(addr[:], data))
-
-	// If state snapshotting is active, cache the data til commit
-	if s.snap != nil {
-		// If the account is an empty resurrection, unmark the storage nil-ness
-		if storage, ok := s.snapStorage[obj.addrHash]; storage == nil && ok {
-			delete(s.snapStorage, obj.addrHash)
-		}
-		s.snapAccounts[obj.addrHash] = snapshot.AccountRLP(obj.data.Nonce, obj.data.Balance, obj.data.Root, obj.data.CodeHash)
-	}
 }
 
 // deleteStateObject removes the given object from the state trie.
@@ -483,12 +477,6 @@ func (s *StateDB) deleteStateObject(obj *stateObject) {
 	// Delete the account from the trie
 	addr := obj.Address()
 	s.setError(s.trie.TryDelete(addr[:]))
-
-	// If state snapshotting is active, cache the data til commit
-	if s.snap != nil {
-		s.snapAccounts[obj.addrHash] = nil // We need to maintain account deletions explicitly
-		s.snapStorage[obj.addrHash] = nil  // We need to maintain storage deletions explicitly
-	}
 }
 
 // getStateObject retrieves a state object given by the address, returning nil if
@@ -737,8 +725,23 @@ func (s *StateDB) Finalise(deleteEmptyObjects bool) {
 		}
 		if obj.suicided || (deleteEmptyObjects && obj.empty()) {
 			obj.deleted = true
+
+			// If state snapshotting is active, also mark the destruction there.
+			// Note, we can't do this only at the end of a block because multiple
+			// transactions within the same block might self destruct and then
+			// ressurrect an account and the snapshotter needs both events.
+			if s.snap != nil {
+				s.snapDestructs[obj.addrHash] = struct{}{} // We need to maintain account deletions explicitly (will remain set indefinitely)
+				delete(s.snapAccounts, obj.addrHash)       // Clear out any previously updated account data (may be recreated via a ressurrect)
+				delete(s.snapStorage, obj.addrHash)        // Clear out any previously updated storage data (may be recreated via a ressurrect)
+			}
 		} else {
 			obj.finalise()
+
+			// If state snapshotting is active, cache the data til commit
+			if s.snap != nil {
+				s.snapAccounts[obj.addrHash] = snapshot.AccountRLP(obj.data.Nonce, obj.data.Balance, obj.data.Root, obj.data.CodeHash)
+			}
 		}
 		s.stateObjectsPending[addr] = struct{}{}
 		s.stateObjectsDirty[addr] = struct{}{}
@@ -842,7 +845,7 @@ func (s *StateDB) Commit(deleteEmptyObjects bool) (common.Hash, error) {
 		}
 		// Only update if there's a state transition (skip empty Clique blocks)
 		if parent := s.snap.Root(); parent != root {
-			if err := s.snaps.Update(root, parent, s.snapAccounts, s.snapStorage); err != nil {
+			if err := s.snaps.Update(root, parent, s.snapDestructs, s.snapAccounts, s.snapStorage); err != nil {
 				log.Warn("Failed to update snapshot tree", "from", parent, "to", root, "err", err)
 			}
 			if err := s.snaps.Cap(root, 127); err != nil { // Persistent layer is 128th, the last available trie

core/vm/opcodes.go

@@ -70,7 +70,7 @@ const (
 	SHR
 	SAR
 
-	SHA3 = 0x20
+	SHA3 OpCode = 0x20
 )
 
 // 0x30 range - closure state.
@@ -101,8 +101,8 @@ const (
 	NUMBER
 	DIFFICULTY
 	GASLIMIT
-	CHAINID     = 0x46
-	SELFBALANCE = 0x47
+	CHAINID     OpCode = 0x46
+	SELFBALANCE OpCode = 0x47
 )
 
 // 0x50 range - 'storage' and execution.
@@ -213,10 +213,9 @@ const (
 	RETURN
 	DELEGATECALL
 	CREATE2
-	STATICCALL = 0xfa
-
-	REVERT       = 0xfd
-	SELFDESTRUCT = 0xff
+	STATICCALL   OpCode = 0xfa
+	REVERT       OpCode = 0xfd
+	SELFDESTRUCT OpCode = 0xff
 )
 
 // Since the opcodes aren't all in order we can't use a regular slice.