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core/state/snapshot: unlink snapshots from blocks, quad->linear cleanup

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This commit is contained in:
Péter Szilágyi 2019-11-22 13:23:49 +02:00
parent cdf3f016df
commit d754091a87
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GPG Key ID: E9AE538CEDF8293D
12 changed files with 203 additions and 206 deletions
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10
core/blockchain.go
View File

@ -140,10 +140,10 @@ type BlockChain struct {
chainConfig *params.ChainConfig // Chain & network configuration
cacheConfig *CacheConfig // Cache configuration for pruning
db ethdb.Database // Low level persistent database to store final content in
snaps *snapshot.SnapshotTree // Snapshot tree for fast trie leaf access
triegc *prque.Prque // Priority queue mapping block numbers to tries to gc
gcproc time.Duration // Accumulates canonical block processing for trie dumping
db ethdb.Database // Low level persistent database to store final content in
snaps *snapshot.Tree // Snapshot tree for fast trie leaf access
triegc *prque.Prque // Priority queue mapping block numbers to tries to gc
gcproc time.Duration // Accumulates canonical block processing for trie dumping
hc *HeaderChain
rmLogsFeed event.Feed
@ -301,7 +301,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
}
// Load any existing snapshot, regenerating it if loading failed
head := bc.CurrentBlock()
if bc.snaps, err = snapshot.New(bc.db, "snapshot.rlp", head.NumberU64(), head.Root()); err != nil {
if bc.snaps, err = snapshot.New(bc.db, "snapshot.rlp", head.Root()); err != nil {
return nil, err
}
// Take ownership of this particular state

40
core/rawdb/accessors_snapshot.go
View File

@ -17,38 +17,36 @@
package rawdb
import (
"encoding/binary"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
)
// ReadSnapshotBlock retrieves the number and root of the block whose state is
// contained in the persisted snapshot.
func ReadSnapshotBlock(db ethdb.KeyValueReader) (uint64, common.Hash) {
data, _ := db.Get(snapshotBlockKey)
if len(data) != 8+common.HashLength {
return 0, common.Hash{}
// ReadSnapshotRoot retrieves the root of the block whose state is contained in
// the persisted snapshot.
func ReadSnapshotRoot(db ethdb.KeyValueReader) common.Hash {
data, _ := db.Get(snapshotRootKey)
if len(data) != common.HashLength {
return common.Hash{}
}
return binary.BigEndian.Uint64(data[:8]), common.BytesToHash(data[8:])
return common.BytesToHash(data)
}
// WriteSnapshotBlock stores the number and root of the block whose state is
// contained in the persisted snapshot.
func WriteSnapshotBlock(db ethdb.KeyValueWriter, number uint64, root common.Hash) {
if err := db.Put(snapshotBlockKey, append(encodeBlockNumber(number), root.Bytes()...)); err != nil {
log.Crit("Failed to store snapsnot block's number and root", "err", err)
// WriteSnapshotRoot stores the root of the block whose state is contained in
// the persisted snapshot.
func WriteSnapshotRoot(db ethdb.KeyValueWriter, root common.Hash) {
if err := db.Put(snapshotRootKey, root[:]); err != nil {
log.Crit("Failed to store snapshot root", "err", err)
}
}
// DeleteSnapshotBlock deletes the number and hash of the block whose state is
// contained in the persisted snapshot. Since snapshots are not immutable, this
// method can be used during updates, so a crash or failure will mark the entire
// snapshot invalid.
func DeleteSnapshotBlock(db ethdb.KeyValueWriter) {
if err := db.Delete(snapshotBlockKey); err != nil {
log.Crit("Failed to remove snapsnot block's number and hash", "err", err)
// DeleteSnapshotRoot deletes the hash of the block whose state is contained in
// the persisted snapshot. Since snapshots are not immutable, this method can
// be used during updates, so a crash or failure will mark the entire snapshot
// invalid.
func DeleteSnapshotRoot(db ethdb.KeyValueWriter) {
if err := db.Delete(snapshotRootKey); err != nil {
log.Crit("Failed to remove snapshot root", "err", err)
}
}

4
core/rawdb/schema.go
View File

@ -41,8 +41,8 @@ var (
// fastTrieProgressKey tracks the number of trie entries imported during fast sync.
fastTrieProgressKey = []byte("TrieSync")
// snapshotBlockKey tracks the number and hash of the last snapshot.
snapshotBlockKey = []byte("SnapshotBlock")
// snapshotRootKey tracks the number and hash of the last snapshot.
snapshotRootKey = []byte("SnapshotRoot")
// Data item prefixes (use single byte to avoid mixing data types, avoid `i`, used for indexes).
headerPrefix = []byte("h") // headerPrefix + num (uint64 big endian) + hash -> header

27
core/state/snapshot/difflayer.go
View File

@ -36,9 +36,8 @@ type diffLayer struct {
parent snapshot // Parent snapshot modified by this one, never nil
memory uint64 // Approximate guess as to how much memory we use
number uint64 // Block number to which this snapshot diff belongs to
root common.Hash // Root hash to which this snapshot diff belongs to
stale bool // Signals that the layer became stale (state progressed)
root common.Hash // Root hash to which this snapshot diff belongs to
stale bool // Signals that the layer became stale (state progressed)
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)
@ -50,11 +49,10 @@ type diffLayer struct {
// 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, number uint64, root common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
func newDiffLayer(parent snapshot, root common.Hash, 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,
number: number,
root: root,
accountData: accounts,
storageData: storage,
@ -63,7 +61,6 @@ func newDiffLayer(parent snapshot, number uint64, root common.Hash, accounts map
for _, data := range accounts {
dl.memory += uint64(len(data))
}
// Fill the storage hashes and sort them for the iterator
dl.storageList = make(map[common.Hash][]common.Hash)
@ -93,9 +90,18 @@ func newDiffLayer(parent snapshot, number uint64, root common.Hash, accounts map
return dl
}
// Info returns the block number and root hash for which this snapshot was made.
func (dl *diffLayer) Info() (uint64, common.Hash) {
return dl.number, dl.root
// Root returns the root hash for which this snapshot was made.
func (dl *diffLayer) Root() common.Hash {
return dl.root
}
// Stale return whether this layer has become stale (was flattened across) or if
// it's still live.
func (dl *diffLayer) Stale() bool {
dl.lock.RLock()
defer dl.lock.RUnlock()
return dl.stale
}
// Account directly retrieves the account associated with a particular hash in
@ -164,7 +170,7 @@ func (dl *diffLayer) 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.
func (dl *diffLayer) Update(blockRoot common.Hash, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) *diffLayer {
return newDiffLayer(dl, dl.number+1, blockRoot, accounts, storage)
return newDiffLayer(dl, blockRoot, accounts, storage)
}
// flatten pushes all data from this point downwards, flattening everything into
@ -213,7 +219,6 @@ func (dl *diffLayer) flatten() snapshot {
// Return the combo parent
return &diffLayer{
parent: parent.parent,
number: dl.number,
root: dl.root,
storageList: parent.storageList,
storageData: parent.storageData,

25
core/state/snapshot/difflayer_journal.go
View File

@ -43,18 +43,12 @@ type journalStorage struct {
// diff and verifying that it can be linked to the requested parent.
func loadDiffLayer(parent snapshot, r *rlp.Stream) (snapshot, error) {
// Read the next diff journal entry
var (
number uint64
root common.Hash
)
if err := r.Decode(&number); err != nil {
var root common.Hash
if err := r.Decode(&root); err != nil {
// The first read may fail with EOF, marking the end of the journal
if err == io.EOF {
return parent, nil
}
return nil, fmt.Errorf("load diff number: %v", err)
}
if err := r.Decode(&root); err != nil {
return nil, fmt.Errorf("load diff root: %v", err)
}
var accounts []journalAccount
@ -77,13 +71,7 @@ func loadDiffLayer(parent snapshot, r *rlp.Stream) (snapshot, error) {
}
storageData[entry.Hash] = slots
}
// Validate the block number to avoid state corruption
if parent, ok := parent.(*diffLayer); ok {
if number != parent.number+1 {
return nil, fmt.Errorf("snapshot chain broken: block #%d after #%d", number, parent.number)
}
}
return loadDiffLayer(newDiffLayer(parent, number, root, accountData, storageData), r)
return loadDiffLayer(newDiffLayer(parent, root, accountData, storageData), r)
}
// journal is the internal version of Journal that also returns the journal file
@ -113,13 +101,8 @@ func (dl *diffLayer) journal() (io.WriteCloser, error) {
writer.Close()
return nil, ErrSnapshotStale
}
buf := bufio.NewWriter(writer)
// Everything below was journalled, persist this layer too
if err := rlp.Encode(buf, dl.number); err != nil {
buf.Flush()
writer.Close()
return nil, err
}
buf := bufio.NewWriter(writer)
if err := rlp.Encode(buf, dl.root); err != nil {
buf.Flush()
writer.Close()

56
core/state/snapshot/difflayer_test.go
View File

@ -61,11 +61,11 @@ func TestMergeBasics(t *testing.T) {
}
}
// Add some (identical) layers on top
parent := newDiffLayer(emptyLayer{}, 1, common.Hash{}, accounts, storage)
child := newDiffLayer(parent, 1, common.Hash{}, accounts, storage)
child = newDiffLayer(child, 1, common.Hash{}, accounts, storage)
child = newDiffLayer(child, 1, common.Hash{}, accounts, storage)
child = newDiffLayer(child, 1, common.Hash{}, accounts, storage)
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)
// And flatten
merged := (child.flatten()).(*diffLayer)
@ -122,7 +122,7 @@ func TestMergeDelete(t *testing.T) {
}
// Add some flip-flopping layers on top
parent := newDiffLayer(emptyLayer{}, 1, common.Hash{}, flip(), storage)
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)
@ -139,10 +139,6 @@ func TestMergeDelete(t *testing.T) {
// And flatten
merged := (child.flatten()).(*diffLayer)
// check number
if got, exp := merged.number, child.number; got != exp {
t.Errorf("merged layer: wrong number - exp %d got %d", exp, got)
}
if data, _ := merged.Account(h1); data == nil {
t.Errorf("merged layer: expected %x to be non-nil", h1)
}
@ -169,7 +165,7 @@ func TestInsertAndMerge(t *testing.T) {
{
var accounts = make(map[common.Hash][]byte)
var storage = make(map[common.Hash]map[common.Hash][]byte)
parent = newDiffLayer(emptyLayer{}, 1, common.Hash{}, accounts, storage)
parent = newDiffLayer(emptyLayer{}, common.Hash{}, accounts, storage)
}
{
var accounts = make(map[common.Hash][]byte)
@ -178,7 +174,7 @@ func TestInsertAndMerge(t *testing.T) {
accstorage := make(map[common.Hash][]byte)
storage[acc] = accstorage
storage[acc][slot] = []byte{0x01}
child = newDiffLayer(parent, 2, common.Hash{}, accounts, storage)
child = newDiffLayer(parent, common.Hash{}, accounts, storage)
}
// And flatten
merged := (child.flatten()).(*diffLayer)
@ -200,11 +196,12 @@ func (emptyLayer) Journal() error {
panic("implement me")
}
func (emptyLayer) Info() (uint64, common.Hash) {
return 0, common.Hash{}
func (emptyLayer) Stale() bool {
panic("implement me")
}
func (emptyLayer) Number() uint64 {
return 0
func (emptyLayer) Root() common.Hash {
return common.Hash{}
}
func (emptyLayer) Account(hash common.Hash) (*Account, error) {
@ -227,8 +224,6 @@ func (emptyLayer) Storage(accountHash, storageHash common.Hash) ([]byte, error)
// BenchmarkSearch-6 500000 3723 ns/op (10k per layer, only top-level RLock()
func BenchmarkSearch(b *testing.B) {
// First, we set up 128 diff layers, with 1K items each
blocknum := uint64(0)
fill := func(parent snapshot) *diffLayer {
accounts := make(map[common.Hash][]byte)
storage := make(map[common.Hash]map[common.Hash][]byte)
@ -236,10 +231,8 @@ func BenchmarkSearch(b *testing.B) {
for i := 0; i < 10000; i++ {
accounts[randomHash()] = randomAccount()
}
blocknum++
return newDiffLayer(parent, blocknum, common.Hash{}, accounts, storage)
return newDiffLayer(parent, common.Hash{}, accounts, storage)
}
var layer snapshot
layer = emptyLayer{}
for i := 0; i < 128; i++ {
@ -261,8 +254,6 @@ func BenchmarkSearch(b *testing.B) {
// BenchmarkSearchSlot-6 100000 14551 ns/op (when checking parent number using atomic)
func BenchmarkSearchSlot(b *testing.B) {
// First, we set up 128 diff layers, with 1K items each
blocknum := uint64(0)
accountKey := common.Hash{}
storageKey := common.HexToHash("0x1337")
accountRLP := randomAccount()
@ -278,16 +269,13 @@ func BenchmarkSearchSlot(b *testing.B) {
accStorage[randomHash()] = value
storage[accountKey] = accStorage
}
blocknum++
return newDiffLayer(parent, blocknum, common.Hash{}, accounts, storage)
return newDiffLayer(parent, common.Hash{}, accounts, storage)
}
var layer snapshot
layer = emptyLayer{}
for i := 0; i < 128; i++ {
layer = fill(layer)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
layer.Storage(accountKey, storageKey)
@ -300,7 +288,7 @@ func BenchmarkSearchSlot(b *testing.B) {
// Without sorting and tracking accountlist
// BenchmarkFlatten-6 300 5511511 ns/op
func BenchmarkFlatten(b *testing.B) {
fill := func(parent snapshot, blocknum int) *diffLayer {
fill := func(parent snapshot) *diffLayer {
accounts := make(map[common.Hash][]byte)
storage := make(map[common.Hash]map[common.Hash][]byte)
@ -317,7 +305,7 @@ func BenchmarkFlatten(b *testing.B) {
}
storage[accountKey] = accStorage
}
return newDiffLayer(parent, uint64(blocknum), common.Hash{}, accounts, storage)
return newDiffLayer(parent, common.Hash{}, accounts, storage)
}
b.ResetTimer()
@ -327,7 +315,7 @@ func BenchmarkFlatten(b *testing.B) {
var layer snapshot
layer = emptyLayer{}
for i := 1; i < 128; i++ {
layer = fill(layer, i)
layer = fill(layer)
}
b.StartTimer()
@ -336,7 +324,6 @@ func BenchmarkFlatten(b *testing.B) {
if !ok {
break
}
layer = dl.flatten()
}
b.StopTimer()
@ -351,7 +338,7 @@ func BenchmarkFlatten(b *testing.B) {
// BenchmarkJournal-6 1 1471373923 ns/ops
// BenchmarkJournal-6 1 1208083335 ns/op // bufio writer
func BenchmarkJournal(b *testing.B) {
fill := func(parent snapshot, blocknum int) *diffLayer {
fill := func(parent snapshot) *diffLayer {
accounts := make(map[common.Hash][]byte)
storage := make(map[common.Hash]map[common.Hash][]byte)
@ -368,15 +355,14 @@ func BenchmarkJournal(b *testing.B) {
}
storage[accountKey] = accStorage
}
return newDiffLayer(parent, uint64(blocknum), common.Hash{}, accounts, storage)
return newDiffLayer(parent, common.Hash{}, accounts, storage)
}
var layer snapshot
layer = &diskLayer{
journal: path.Join(os.TempDir(), "difflayer_journal.tmp"),
}
for i := 1; i < 128; i++ {
layer = fill(layer, i)
layer = fill(layer)
}
b.ResetTimer()

22
core/state/snapshot/disklayer.go
View File

@ -32,16 +32,24 @@ type diskLayer struct {
db ethdb.KeyValueStore // Key-value store containing the base snapshot
cache *bigcache.BigCache // Cache to avoid hitting the disk for direct access
number uint64 // Block number of the base snapshot
root common.Hash // Root hash of the base snapshot
stale bool // Signals that the layer became stale (state progressed)
root common.Hash // Root hash of the base snapshot
stale bool // Signals that the layer became stale (state progressed)
lock sync.RWMutex
}
// Info returns the block number and root hash for which this snapshot was made.
func (dl *diskLayer) Info() (uint64, common.Hash) {
return dl.number, dl.root
// Root returns root hash for which this snapshot was made.
func (dl *diskLayer) Root() common.Hash {
return dl.root
}
// Stale return whether this layer has become stale (was flattened across) or if
// it's still live.
func (dl *diskLayer) Stale() bool {
dl.lock.RLock()
defer dl.lock.RUnlock()
return dl.stale
}
// Account directly retrieves the account associated with a particular hash in
@ -123,7 +131,7 @@ func (dl *diskLayer) Storage(accountHash, storageHash common.Hash) ([]byte, erro
// 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, dl.number+1, blockHash, accounts, storage)
return newDiffLayer(dl, blockHash, accounts, storage)
}
// Journal commits an entire diff hierarchy to disk into a single journal file.

11
core/state/snapshot/generate.go
View File

@ -85,7 +85,7 @@ func wipeSnapshot(db ethdb.KeyValueStore) error {
}
it.Release()
rawdb.DeleteSnapshotBlock(batch)
rawdb.DeleteSnapshotRoot(batch)
if err := batch.Write(); err != nil {
return err
}
@ -107,7 +107,7 @@ func wipeSnapshot(db ethdb.KeyValueStore) error {
}
// generateSnapshot regenerates a brand new snapshot based on an existing state database and head block.
func generateSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64, headRoot common.Hash) (snapshot, error) {
func generateSnapshot(db ethdb.KeyValueStore, journal string, root common.Hash) (snapshot, error) {
// Wipe any previously existing snapshot from the database
if err := wipeSnapshot(db); err != nil {
return nil, err
@ -124,7 +124,7 @@ func generateSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64,
batch := db.NewBatch()
triedb := trie.NewDatabase(db)
accTrie, err := trie.NewSecure(headRoot, triedb)
accTrie, err := trie.NewSecure(root, triedb)
if err != nil {
return nil, err
}
@ -186,7 +186,7 @@ func generateSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64,
fmt.Printf("Totals: %9s (%d accs, %d nodes) + %9s (%d slots, %d nodes)\n", accountSize.TerminalString(), accountCount, accIt.Nodes, storageSize.TerminalString(), storageCount, storageNodes)
// Update the snapshot block marker and write any remainder data
rawdb.WriteSnapshotBlock(batch, headNumber, headRoot)
rawdb.WriteSnapshotRoot(batch, root)
batch.Write()
batch.Reset()
@ -207,7 +207,6 @@ func generateSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64,
journal: journal,
db: db,
cache: cache,
number: headNumber,
root: headRoot,
root: root,
}, nil
}

10
core/state/snapshot/generate_test.go
View File

@ -47,7 +47,7 @@ func TestWipe(t *testing.T) {
rawdb.WriteStorageSnapshot(db, account, randomHash(), randomHash().Bytes())
}
}
rawdb.WriteSnapshotBlock(db, 123, randomHash())
rawdb.WriteSnapshotRoot(db, randomHash())
// Add some random non-snapshot data too to make wiping harder
for i := 0; i < 65536; i++ {
@ -76,8 +76,8 @@ func TestWipe(t *testing.T) {
if items != 128+128*1024 {
t.Fatalf("snapshot size mismatch: have %d, want %d", items, 128+128*1024)
}
if number, hash := rawdb.ReadSnapshotBlock(db); number != 123 || hash == (common.Hash{}) {
t.Errorf("snapshot block marker mismatch: have #%d [%#x], want #%d [<not-nil>]", number, hash, 123)
if hash := rawdb.ReadSnapshotRoot(db); hash == (common.Hash{}) {
t.Errorf("snapshot block marker mismatch: have %#x, want <not-nil>", hash)
}
// Wipe all snapshot entries from the database
if err := wipeSnapshot(db); err != nil {
@ -93,8 +93,8 @@ func TestWipe(t *testing.T) {
t.Errorf("snapshot entry remained after wipe: %x", key)
}
}
if number, hash := rawdb.ReadSnapshotBlock(db); number != 0 || hash != (common.Hash{}) {
t.Errorf("snapshot block marker remained after wipe: #%d [%#x]", number, hash)
if hash := rawdb.ReadSnapshotRoot(db); hash != (common.Hash{}) {
t.Errorf("snapshot block marker remained after wipe: %#x", hash)
}
// Iterate over the database and ensure miscellaneous items are present
items = 0

175
core/state/snapshot/snapshot.go
View File

@ -43,12 +43,16 @@ var (
// layer had been invalidated due to the chain progressing forward far enough
// to not maintain the layer's original state.
ErrSnapshotStale = errors.New("snapshot stale")
// errSnapshotCycle is returned if a snapshot is attempted to be inserted
// that forms a cycle in the snapshot tree.
errSnapshotCycle = errors.New("snapshot cycle")
)
// Snapshot represents the functionality supported by a snapshot storage layer.
type Snapshot interface {
// Info returns the block number and root hash for which this snapshot was made.
Info() (uint64, common.Hash)
// Root returns the root hash for which this snapshot was made.
Root() common.Hash
// Account directly retrieves the account associated with a particular hash in
// the snapshot slim data format.
@ -77,6 +81,10 @@ type snapshot interface {
// This is meant to be used during shutdown to persist the snapshot without
// flattening everything down (bad for reorgs).
Journal() error
// Stale return whether this layer has become stale (was flattened across) or
// if it's still live.
Stale() bool
}
// SnapshotTree is an Ethereum state snapshot tree. It consists of one persistent
@ -88,7 +96,7 @@ type snapshot interface {
// The goal of a state snapshot is twofold: to allow direct access to account and
// storage data to avoid expensive multi-level trie lookups; and to allow sorted,
// cheap iteration of the account/storage tries for sync aid.
type SnapshotTree struct {
type Tree struct {
layers map[common.Hash]snapshot // Collection of all known layers // TODO(karalabe): split Clique overlaps
lock sync.RWMutex
}
@ -99,22 +107,21 @@ type SnapshotTree struct {
//
// If the snapshot is missing or inconsistent, the entirety is deleted and will
// be reconstructed from scratch based on the tries in the key-value store.
func New(db ethdb.KeyValueStore, journal string, headNumber uint64, headRoot common.Hash) (*SnapshotTree, error) {
func New(db ethdb.KeyValueStore, journal string, root common.Hash) (*Tree, error) {
// Attempt to load a previously persisted snapshot
head, err := loadSnapshot(db, journal, headNumber, headRoot)
head, err := loadSnapshot(db, journal, root)
if err != nil {
log.Warn("Failed to load snapshot, regenerating", "err", err)
if head, err = generateSnapshot(db, journal, headNumber, headRoot); err != nil {
if head, err = generateSnapshot(db, journal, root); err != nil {
return nil, err
}
}
// Existing snapshot loaded or one regenerated, seed all the layers
snap := &SnapshotTree{
snap := &Tree{
layers: make(map[common.Hash]snapshot),
}
for head != nil {
_, root := head.Info()
snap.layers[root] = head
snap.layers[head.Root()] = head
switch self := head.(type) {
case *diffLayer:
@ -130,54 +137,57 @@ func New(db ethdb.KeyValueStore, journal string, headNumber uint64, headRoot com
// Snapshot retrieves a snapshot belonging to the given block root, or nil if no
// snapshot is maintained for that block.
func (st *SnapshotTree) Snapshot(blockRoot common.Hash) Snapshot {
st.lock.RLock()
defer st.lock.RUnlock()
func (t *Tree) Snapshot(blockRoot common.Hash) Snapshot {
t.lock.RLock()
defer t.lock.RUnlock()
return st.layers[blockRoot]
return t.layers[blockRoot]
}
// 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 (st *SnapshotTree) 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, 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).
//
// Although we could silently ignore this internally, it should be the caller's
// responsibility to avoid even attempting to insert such a snapshot.
if blockRoot == parentRoot {
return errSnapshotCycle
}
// Generate a new snapshot on top of the parent
parent := st.Snapshot(parentRoot).(snapshot)
parent := t.Snapshot(parentRoot).(snapshot)
if parent == nil {
return fmt.Errorf("parent [%#x] snapshot missing", parentRoot)
}
snap := parent.Update(blockRoot, accounts, storage)
// Save the new snapshot for later
st.lock.Lock()
defer st.lock.Unlock()
t.lock.Lock()
defer t.lock.Unlock()
st.layers[snap.root] = snap
t.layers[snap.root] = snap
return nil
}
// Cap traverses downwards the snapshot tree from a head block hash until the
// number of allowed layers are crossed. All layers beyond the permitted number
// are flattened downwards.
func (st *SnapshotTree) Cap(blockRoot common.Hash, layers int, memory uint64) error {
func (t *Tree) Cap(root common.Hash, layers int, memory uint64) error {
// Retrieve the head snapshot to cap from
var snap snapshot
if s := st.Snapshot(blockRoot); s == nil {
return fmt.Errorf("snapshot [%#x] missing", blockRoot)
} else {
snap = s.(snapshot)
snap := t.Snapshot(root)
if snap == nil {
return fmt.Errorf("snapshot [%#x] missing", root)
}
diff, ok := snap.(*diffLayer)
if !ok {
return fmt.Errorf("snapshot [%#x] is disk layer", blockRoot)
return fmt.Errorf("snapshot [%#x] is disk layer", root)
}
// Run the internal capping and discard all stale layers
st.lock.Lock()
defer st.lock.Unlock()
t.lock.Lock()
defer t.lock.Unlock()
var (
diskNumber uint64
diffNumber uint64
)
// Flattening the bottom-most diff layer requires special casing since there's
// no child to rewire to the grandparent. In that case we can fake a temporary
// child for the capping and then remove it.
@ -188,8 +198,9 @@ func (st *SnapshotTree) Cap(blockRoot common.Hash, layers int, memory uint64) er
base := diffToDisk(diff.flatten().(*diffLayer))
diff.lock.RUnlock()
st.layers[base.root] = base
diskNumber, diffNumber = base.number, base.number
// Replace the entire snapshot tree with the flat base
t.layers = map[common.Hash]snapshot{base.root: base}
return nil
case 1:
// If full flattening was requested, flatten the diffs but only merge if the
@ -205,59 +216,74 @@ func (st *SnapshotTree) Cap(blockRoot common.Hash, layers int, memory uint64) er
}
diff.lock.RUnlock()
// If all diff layers were removed, replace the entire snapshot tree
if base != nil {
st.layers[base.root] = base
diskNumber, diffNumber = base.number, base.number
} else {
st.layers[bottom.root] = bottom
diskNumber, diffNumber = bottom.parent.(*diskLayer).number, bottom.number
t.layers = map[common.Hash]snapshot{base.root: base}
return nil
}
// Merge the new aggregated layer into the snapshot tree, clean stales below
t.layers[bottom.root] = bottom
default:
diskNumber, diffNumber = st.cap(diff, layers, memory)
// Many layers requested to be retained, cap normally
t.cap(diff, layers, memory)
}
for root, snap := range st.layers {
if number, _ := snap.Info(); number != diskNumber && number < diffNumber {
delete(st.layers, root)
// Remove any layer that is stale or links into a stale layer
children := make(map[common.Hash][]common.Hash)
for root, snap := range t.layers {
if diff, ok := snap.(*diffLayer); ok {
parent := diff.parent.Root()
children[parent] = append(children[parent], root)
}
}
var remove func(root common.Hash)
remove = func(root common.Hash) {
delete(t.layers, root)
for _, child := range children[root] {
remove(child)
}
delete(children, root)
}
for root, snap := range t.layers {
if snap.Stale() {
remove(root)
}
}
return nil
}
// cap traverses downwards the diff tree until the number of allowed layers are
// crossed. All diffs beyond the permitted number are flattened downwards. If
// the layer limit is reached, memory cap is also enforced (but not before). The
// block numbers for the disk layer and first diff layer are returned for GC.
func (st *SnapshotTree) cap(diff *diffLayer, layers int, memory uint64) (uint64, uint64) {
// crossed. All diffs beyond the permitted number are flattened downwards. If the
// layer limit is reached, memory cap is also enforced (but not before).
func (t *Tree) cap(diff *diffLayer, layers int, memory uint64) {
// Dive until we run out of layers or reach the persistent database
for ; layers > 2; layers-- {
// If we still have diff layers below, continue down
if parent, ok := diff.parent.(*diffLayer); ok {
diff = parent
} else {
// Diff stack too shallow, return block numbers without modifications
return diff.parent.(*diskLayer).number, diff.number
// Diff stack too shallow, return without modifications
return
}
}
// We're out of layers, flatten anything below, stopping if it's the disk or if
// the memory limit is not yet exceeded.
switch parent := diff.parent.(type) {
case *diskLayer:
return parent.number, diff.number
return
case *diffLayer:
// Flatten the parent into the grandparent. The flattening internally obtains a
// write lock on grandparent.
flattened := parent.flatten().(*diffLayer)
st.layers[flattened.root] = flattened
t.layers[flattened.root] = flattened
diff.lock.Lock()
defer diff.lock.Unlock()
diff.parent = flattened
if flattened.memory < memory {
diskNumber, _ := flattened.parent.Info()
return diskNumber, flattened.number
return
}
default:
panic(fmt.Sprintf("unknown data layer: %T", parent))
@ -269,10 +295,8 @@ func (st *SnapshotTree) cap(diff *diffLayer, layers int, memory uint64) (uint64,
base := diffToDisk(bottom)
bottom.lock.RUnlock()
st.layers[base.root] = base
t.layers[base.root] = base
diff.parent = base
return base.number, diff.number
}
// diffToDisk merges a bottom-most diff into the persistent disk layer underneath
@ -284,7 +308,7 @@ func diffToDisk(bottom *diffLayer) *diskLayer {
)
// Start by temporarily deleting the current snapshot block marker. This
// ensures that in the case of a crash, the entire snapshot is invalidated.
rawdb.DeleteSnapshotBlock(batch)
rawdb.DeleteSnapshotRoot(batch)
// Mark the original base as stale as we're going to create a new wrapper
base.lock.Lock()
@ -341,13 +365,12 @@ func diffToDisk(bottom *diffLayer) *diskLayer {
}
}
// Update the snapshot block marker and write any remainder data
rawdb.WriteSnapshotBlock(batch, bottom.number, bottom.root)
rawdb.WriteSnapshotRoot(batch, bottom.root)
if err := batch.Write(); err != nil {
log.Crit("Failed to write leftover snapshot", "err", err)
}
return &diskLayer{
root: bottom.root,
number: bottom.number,
cache: base.cache,
db: base.db,
journal: base.journal,
@ -357,27 +380,25 @@ func diffToDisk(bottom *diffLayer) *diskLayer {
// Journal commits an entire diff hierarchy to disk into a single journal file.
// This is meant to be used during shutdown to persist the snapshot without
// flattening everything down (bad for reorgs).
func (st *SnapshotTree) Journal(blockRoot common.Hash) error {
// Retrieve the head snapshot to journal from
var snap snapshot
if s := st.Snapshot(blockRoot); s == nil {
func (t *Tree) Journal(blockRoot common.Hash) error {
// Retrieve the head snapshot to journal from var snap snapshot
snap := t.Snapshot(blockRoot)
if snap == nil {
return fmt.Errorf("snapshot [%#x] missing", blockRoot)
} else {
snap = s.(snapshot)
}
// Run the journaling
st.lock.Lock()
defer st.lock.Unlock()
t.lock.Lock()
defer t.lock.Unlock()
return snap.Journal()
return snap.(snapshot).Journal()
}
// loadSnapshot loads a pre-existing state snapshot backed by a key-value store.
func loadSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64, headRoot common.Hash) (snapshot, error) {
func loadSnapshot(db ethdb.KeyValueStore, journal string, root common.Hash) (snapshot, error) {
// Retrieve the block number and hash of the snapshot, failing if no snapshot
// is present in the database (or crashed mid-update).
number, root := rawdb.ReadSnapshotBlock(db)
if root == (common.Hash{}) {
baseRoot := rawdb.ReadSnapshotRoot(db)
if baseRoot == (common.Hash{}) {
return nil, errors.New("missing or corrupted snapshot")
}
cache, _ := bigcache.NewBigCache(bigcache.Config{ // TODO(karalabe): dedup
@ -391,16 +412,14 @@ func loadSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64, hea
journal: journal,
db: db,
cache: cache,
number: number,
root: root,
root: baseRoot,
}
// Load all the snapshot diffs from the journal, failing if their chain is broken
// or does not lead from the disk snapshot to the specified head.
if _, err := os.Stat(journal); os.IsNotExist(err) {
// Journal doesn't exist, don't worry if it's not supposed to
if number != headNumber || root != headRoot {
return nil, fmt.Errorf("snapshot journal missing, head doesn't match snapshot: #%d [%#x] vs. #%d [%#x]",
headNumber, headRoot, number, root)
if baseRoot != root {
return nil, fmt.Errorf("snapshot journal missing, head doesn't match snapshot: have %#x, want %#x", baseRoot, root)
}
return base, nil
}
@ -414,10 +433,8 @@ func loadSnapshot(db ethdb.KeyValueStore, journal string, headNumber uint64, hea
}
// Entire snapshot journal loaded, sanity check the head and return
// Journal doesn't exist, don't worry if it's not supposed to
number, root = snapshot.Info()
if number != headNumber || root != headRoot {
return nil, fmt.Errorf("head doesn't match snapshot: #%d [%#x] vs. #%d [%#x]",
headNumber, headRoot, number, root)
if head := snapshot.Root(); head != root {
return nil, fmt.Errorf("head doesn't match snapshot: have %#x, want %#x", head, root)
}
return snapshot, nil
}

11
core/state/snapshot/snapshot_test.go
View File

@ -37,7 +37,7 @@ func TestDiskLayerExternalInvalidationFullFlatten(t *testing.T) {
root: common.HexToHash("0x01"),
cache: cache,
}
snaps := &SnapshotTree{
snaps := &Tree{
layers: map[common.Hash]snapshot{
base.root: base,
},
@ -83,7 +83,7 @@ func TestDiskLayerExternalInvalidationPartialFlatten(t *testing.T) {
root: common.HexToHash("0x01"),
cache: cache,
}
snaps := &SnapshotTree{
snaps := &Tree{
layers: map[common.Hash]snapshot{
base.root: base,
},
@ -132,7 +132,7 @@ func TestDiffLayerExternalInvalidationFullFlatten(t *testing.T) {
root: common.HexToHash("0x01"),
cache: cache,
}
snaps := &SnapshotTree{
snaps := &Tree{
layers: map[common.Hash]snapshot{
base.root: base,
},
@ -181,7 +181,7 @@ func TestDiffLayerExternalInvalidationPartialFlatten(t *testing.T) {
root: common.HexToHash("0x01"),
cache: cache,
}
snaps := &SnapshotTree{
snaps := &Tree{
layers: map[common.Hash]snapshot{
base.root: base,
},
@ -213,7 +213,6 @@ func TestDiffLayerExternalInvalidationPartialFlatten(t *testing.T) {
if got := len(snaps.layers); got != exp {
t.Errorf("layers modified, got %d exp %d", got, exp)
}
// Flatten the diff layer into the bottom accumulator
if err := snaps.Cap(common.HexToHash("0x04"), 2, 1024*1024); err != nil {
t.Fatalf("failed to flatten diff layer into accumulator: %v", err)
@ -247,7 +246,7 @@ func TestPostCapBasicDataAccess(t *testing.T) {
root: common.HexToHash("0x01"),
cache: cache,
}
snaps := &SnapshotTree{
snaps := &Tree{
layers: map[common.Hash]snapshot{
base.root: base,
},

18
core/state/statedb.go
View File

@ -68,7 +68,7 @@ type StateDB struct {
db Database
trie Trie
snaps *snapshot.SnapshotTree
snaps *snapshot.Tree
snap snapshot.Snapshot
snapAccounts map[common.Hash][]byte
snapStorage map[common.Hash]map[common.Hash][]byte
@ -117,7 +117,7 @@ type StateDB struct {
}
// Create a new state from a given trie.
func New(root common.Hash, db Database, snaps *snapshot.SnapshotTree) (*StateDB, error) {
func New(root common.Hash, db Database, snaps *snapshot.Tree) (*StateDB, error) {
tr, err := db.OpenTrie(root)
if err != nil {
return nil, err
@ -840,12 +840,14 @@ func (s *StateDB) Commit(deleteEmptyObjects bool) (common.Hash, error) {
if metrics.EnabledExpensive {
defer func(start time.Time) { s.SnapshotCommits += time.Since(start) }(time.Now())
}
_, parentRoot := s.snap.Info()
if err := s.snaps.Update(root, parentRoot, s.snapAccounts, s.snapStorage); err != nil {
log.Warn("Failed to update snapshot tree", "from", parentRoot, "to", root, "err", err)
}
if err := s.snaps.Cap(root, 16, 4*1024*1024); err != nil {
log.Warn("Failed to cap snapshot tree", "root", root, "layers", 16, "memory", 4*1024*1024, "err", err)
// 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 {
log.Warn("Failed to update snapshot tree", "from", parent, "to", root, "err", err)
}
if err := s.snaps.Cap(root, 16, 4*1024*1024); err != nil {
log.Warn("Failed to cap snapshot tree", "root", root, "layers", 16, "memory", 4*1024*1024, "err", err)
}
}
s.snap, s.snapAccounts, s.snapStorage = nil, nil, nil
}