all: port boring changes from pbss (#27176)

* all: port boring changes from pbss

* core, trie: address comments from martin

* trie: minor fixes

* core/rawdb: update comment

* core, eth, tests, trie: address comments

* tests, trie: add extra check when update trie database

* trie/triedb/hashdb: degrade the error to warning

core/blockchain.go

@@ -982,8 +982,8 @@ func (bc *BlockChain) Stop() {
 		}
 	}
 	// Flush the collected preimages to disk
-	if err := bc.stateCache.TrieDB().CommitPreimages(); err != nil {
-		log.Error("Failed to commit trie preimages", "err", err)
+	if err := bc.stateCache.TrieDB().Close(); err != nil {
+		log.Error("Failed to close trie db", "err", err)
 	}
 	// Ensure all live cached entries be saved into disk, so that we can skip
 	// cache warmup when node restarts.

core/blockchain_test.go

@@ -1701,7 +1701,7 @@ func TestTrieForkGC(t *testing.T) {
 		chain.stateCache.TrieDB().Dereference(blocks[len(blocks)-1-i].Root())
 		chain.stateCache.TrieDB().Dereference(forks[len(blocks)-1-i].Root())
 	}
-	if len(chain.stateCache.TrieDB().Nodes()) > 0 {
+	if nodes, _ := chain.TrieDB().Size(); nodes > 0 {
 		t.Fatalf("stale tries still alive after garbase collection")
 	}
 }

core/rawdb/schema.go

@@ -22,6 +22,7 @@ import (
 	"encoding/binary"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/metrics"
 )
 
@@ -100,7 +101,7 @@ var (
 	CodePrefix            = []byte("c") // CodePrefix + code hash -> account code
 	skeletonHeaderPrefix  = []byte("S") // skeletonHeaderPrefix + num (uint64 big endian) -> header
 
-	// Path-based trie node scheme.
+	// Path-based storage scheme of merkle patricia trie.
 	trieNodeAccountPrefix = []byte("A") // trieNodeAccountPrefix + hexPath -> trie node
 	trieNodeStoragePrefix = []byte("O") // trieNodeStoragePrefix + accountHash + hexPath -> trie node
 
@@ -248,3 +249,48 @@ func accountTrieNodeKey(path []byte) []byte {
 func storageTrieNodeKey(accountHash common.Hash, path []byte) []byte {
 	return append(append(trieNodeStoragePrefix, accountHash.Bytes()...), path...)
 }
+
+// IsLegacyTrieNode reports whether a provided database entry is a legacy trie
+// node. The characteristics of legacy trie node are:
+// - the key length is 32 bytes
+// - the key is the hash of val
+func IsLegacyTrieNode(key []byte, val []byte) bool {
+	if len(key) != common.HashLength {
+		return false
+	}
+	return bytes.Equal(key, crypto.Keccak256(val))
+}
+
+// IsAccountTrieNode reports whether a provided database entry is an account
+// trie node in path-based state scheme.
+func IsAccountTrieNode(key []byte) (bool, []byte) {
+	if !bytes.HasPrefix(key, trieNodeAccountPrefix) {
+		return false, nil
+	}
+	// The remaining key should only consist a hex node path
+	// whose length is in the range 0 to 64 (64 is excluded
+	// since leaves are always wrapped with shortNode).
+	if len(key) >= len(trieNodeAccountPrefix)+common.HashLength*2 {
+		return false, nil
+	}
+	return true, key[len(trieNodeAccountPrefix):]
+}
+
+// IsStorageTrieNode reports whether a provided database entry is a storage
+// trie node in path-based state scheme.
+func IsStorageTrieNode(key []byte) (bool, common.Hash, []byte) {
+	if !bytes.HasPrefix(key, trieNodeStoragePrefix) {
+		return false, common.Hash{}, nil
+	}
+	// The remaining key consists of 2 parts:
+	// - 32 bytes account hash
+	// - hex node path whose length is in the range 0 to 64
+	if len(key) < len(trieNodeStoragePrefix)+common.HashLength {
+		return false, common.Hash{}, nil
+	}
+	if len(key) >= len(trieNodeStoragePrefix)+common.HashLength+common.HashLength*2 {
+		return false, common.Hash{}, nil
+	}
+	accountHash := common.BytesToHash(key[len(trieNodeStoragePrefix) : len(trieNodeStoragePrefix)+common.HashLength])
+	return true, accountHash, key[len(trieNodeStoragePrefix)+common.HashLength:]
+}

core/state/database.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 const (
@@ -109,7 +110,7 @@ type Trie interface {
 	// The returned nodeset can be nil if the trie is clean(nothing to commit).
 	// Once the trie is committed, it's not usable anymore. A new trie must
 	// be created with new root and updated trie database for following usage
-	Commit(collectLeaf bool) (common.Hash, *trie.NodeSet)
+	Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet)
 
 	// NodeIterator returns an iterator that returns nodes of the trie. Iteration
 	// starts at the key after the given start key.

core/state/iterator_test.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/crypto"
 )
 
 // Tests that the node iterator indeed walks over the entire database contents.
@@ -85,9 +86,18 @@ func TestNodeIteratorCoverage(t *testing.T) {
 // database entry belongs to a trie node or not.
 func isTrieNode(scheme string, key, val []byte) (bool, common.Hash) {
 	if scheme == rawdb.HashScheme {
-		if len(key) == common.HashLength {
+		if rawdb.IsLegacyTrieNode(key, val) {
 			return true, common.BytesToHash(key)
 		}
+	} else {
+		ok, _ := rawdb.IsAccountTrieNode(key)
+		if ok {
+			return true, crypto.Keccak256Hash(val)
+		}
+		ok, _, _ = rawdb.IsStorageTrieNode(key)
+		if ok {
+			return true, crypto.Keccak256Hash(val)
+		}
 	}
 	return false, common.Hash{}
 }

core/state/snapshot/generate.go

@@ -32,6 +32,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 var (
@@ -363,7 +364,7 @@ func (dl *diskLayer) generateRange(ctx *generatorContext, trieId *trie.ID, prefi
 		}
 		root, nodes := snapTrie.Commit(false)
 		if nodes != nil {
-			tdb.Update(trie.NewWithNodeSet(nodes))
+			tdb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 			tdb.Commit(root, false)
 		}
 		resolver = func(owner common.Hash, path []byte, hash common.Hash) []byte {

core/state/snapshot/generate_test.go

@@ -30,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 	"golang.org/x/crypto/sha3"
 )
 
@@ -144,7 +145,7 @@ type testHelper struct {
 	diskdb  ethdb.Database
 	triedb  *trie.Database
 	accTrie *trie.StateTrie
-	nodes   *trie.MergedNodeSet
+	nodes   *trienode.MergedNodeSet
 }
 
 func newHelper() *testHelper {
@@ -155,7 +156,7 @@ func newHelper() *testHelper {
 		diskdb:  diskdb,
 		triedb:  triedb,
 		accTrie: accTrie,
-		nodes:   trie.NewMergedNodeSet(),
+		nodes:   trienode.NewMergedNodeSet(),
 	}
 }
 
@@ -203,7 +204,7 @@ func (t *testHelper) Commit() common.Hash {
 	if nodes != nil {
 		t.nodes.Merge(nodes)
 	}
-	t.triedb.Update(t.nodes)
+	t.triedb.Update(root, types.EmptyRootHash, t.nodes)
 	t.triedb.Commit(root, false)
 	return root
 }

core/state/state_object.go

@@ -28,7 +28,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/rlp"
-	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 type Code []byte
@@ -350,7 +350,7 @@ func (s *stateObject) updateRoot(db Database) {
 
 // commitTrie submits the storage changes into the storage trie and re-computes
 // the root. Besides, all trie changes will be collected in a nodeset and returned.
-func (s *stateObject) commitTrie(db Database) (*trie.NodeSet, error) {
+func (s *stateObject) commitTrie(db Database) (*trienode.NodeSet, error) {
 	tr, err := s.updateTrie(db)
 	if err != nil {
 		return nil, err

core/state/statedb.go

@@ -34,6 +34,7 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 type revision struct {
@@ -971,7 +972,7 @@ func (s *StateDB) Commit(deleteEmptyObjects bool) (common.Hash, error) {
 		accountTrieNodesDeleted int
 		storageTrieNodesUpdated int
 		storageTrieNodesDeleted int
-		nodes                   = trie.NewMergedNodeSet()
+		nodes                   = trienode.NewMergedNodeSet()
 		codeWriter              = s.db.DiskDB().NewBatch()
 	)
 	for addr := range s.stateObjectsDirty {
@@ -986,7 +987,7 @@ func (s *StateDB) Commit(deleteEmptyObjects bool) (common.Hash, error) {
 			if err != nil {
 				return common.Hash{}, err
 			}
-			// Merge the dirty nodes of storage trie into global set
+			// Merge the dirty nodes of storage trie into global set.
 			if set != nil {
 				if err := nodes.Merge(set); err != nil {
 					return common.Hash{}, err
@@ -1071,7 +1072,7 @@ func (s *StateDB) Commit(deleteEmptyObjects bool) (common.Hash, error) {
 	}
 	if root != origin {
 		start := time.Now()
-		if err := s.db.TrieDB().Update(nodes); err != nil {
+		if err := s.db.TrieDB().Update(root, origin, nodes); err != nil {
 			return common.Hash{}, err
 		}
 		s.originalRoot = root

core/state/sync_test.go

@@ -602,7 +602,8 @@ func TestIncompleteStateSync(t *testing.T) {
 		if len(nodeQueue) > 0 {
 			results := make([]trie.NodeSyncResult, 0, len(nodeQueue))
 			for path, element := range nodeQueue {
-				data, err := srcDb.TrieDB().Node(element.hash)
+				owner, inner := trie.ResolvePath([]byte(element.path))
+				data, err := srcDb.TrieDB().Reader(srcRoot).Node(owner, inner, element.hash)
 				if err != nil {
 					t.Fatalf("failed to retrieve node data for %x", element.hash)
 				}

eth/protocols/snap/sync_test.go

@@ -36,6 +36,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 	"golang.org/x/crypto/sha3"
 )
 
@@ -1389,7 +1390,7 @@ func makeAccountTrieNoStorage(n int) (string, *trie.Trie, entrySlice) {
 	// Commit the state changes into db and re-create the trie
 	// for accessing later.
 	root, nodes := accTrie.Commit(false)
-	db.Update(trie.NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	accTrie, _ = trie.New(trie.StateTrieID(root), db)
 	return db.Scheme(), accTrie, entries
@@ -1451,7 +1452,7 @@ func makeBoundaryAccountTrie(n int) (string, *trie.Trie, entrySlice) {
 	// Commit the state changes into db and re-create the trie
 	// for accessing later.
 	root, nodes := accTrie.Commit(false)
-	db.Update(trie.NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	accTrie, _ = trie.New(trie.StateTrieID(root), db)
 	return db.Scheme(), accTrie, entries
@@ -1467,7 +1468,7 @@ func makeAccountTrieWithStorageWithUniqueStorage(accounts, slots int, code bool)
 		storageRoots   = make(map[common.Hash]common.Hash)
 		storageTries   = make(map[common.Hash]*trie.Trie)
 		storageEntries = make(map[common.Hash]entrySlice)
-		nodes          = trie.NewMergedNodeSet()
+		nodes          = trienode.NewMergedNodeSet()
 	)
 	// Create n accounts in the trie
 	for i := uint64(1); i <= uint64(accounts); i++ {
@@ -1500,7 +1501,7 @@ func makeAccountTrieWithStorageWithUniqueStorage(accounts, slots int, code bool)
 	nodes.Merge(set)
 
 	// Commit gathered dirty nodes into database
-	db.Update(nodes)
+	db.Update(root, types.EmptyRootHash, nodes)
 
 	// Re-create tries with new root
 	accTrie, _ = trie.New(trie.StateTrieID(root), db)
@@ -1522,7 +1523,7 @@ func makeAccountTrieWithStorage(accounts, slots int, code, boundary bool) (strin
 		storageRoots   = make(map[common.Hash]common.Hash)
 		storageTries   = make(map[common.Hash]*trie.Trie)
 		storageEntries = make(map[common.Hash]entrySlice)
-		nodes          = trie.NewMergedNodeSet()
+		nodes          = trienode.NewMergedNodeSet()
 	)
 	// Create n accounts in the trie
 	for i := uint64(1); i <= uint64(accounts); i++ {
@@ -1534,7 +1535,7 @@ func makeAccountTrieWithStorage(accounts, slots int, code, boundary bool) (strin
 		// Make a storage trie
 		var (
 			stRoot    common.Hash
-			stNodes   *trie.NodeSet
+			stNodes   *trienode.NodeSet
 			stEntries entrySlice
 		)
 		if boundary {
@@ -1565,7 +1566,7 @@ func makeAccountTrieWithStorage(accounts, slots int, code, boundary bool) (strin
 	nodes.Merge(set)
 
 	// Commit gathered dirty nodes into database
-	db.Update(nodes)
+	db.Update(root, types.EmptyRootHash, nodes)
 
 	// Re-create tries with new root
 	accTrie, err := trie.New(trie.StateTrieID(root), db)
@@ -1587,7 +1588,7 @@ func makeAccountTrieWithStorage(accounts, slots int, code, boundary bool) (strin
 // makeStorageTrieWithSeed fills a storage trie with n items, returning the
 // not-yet-committed trie and the sorted entries. The seeds can be used to ensure
 // that tries are unique.
-func makeStorageTrieWithSeed(owner common.Hash, n, seed uint64, db *trie.Database) (common.Hash, *trie.NodeSet, entrySlice) {
+func makeStorageTrieWithSeed(owner common.Hash, n, seed uint64, db *trie.Database) (common.Hash, *trienode.NodeSet, entrySlice) {
 	trie, _ := trie.New(trie.StorageTrieID(common.Hash{}, owner, common.Hash{}), db)
 	var entries entrySlice
 	for i := uint64(1); i <= n; i++ {
@@ -1610,7 +1611,7 @@ func makeStorageTrieWithSeed(owner common.Hash, n, seed uint64, db *trie.Databas
 // makeBoundaryStorageTrie constructs a storage trie. Instead of filling
 // storage slots normally, this function will fill a few slots which have
 // boundary hash.
-func makeBoundaryStorageTrie(owner common.Hash, n int, db *trie.Database) (common.Hash, *trie.NodeSet, entrySlice) {
+func makeBoundaryStorageTrie(owner common.Hash, n int, db *trie.Database) (common.Hash, *trienode.NodeSet, entrySlice) {
 	var (
 		entries    entrySlice
 		boundaries []common.Hash

light/postprocess.go

@@ -35,6 +35,7 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 // IndexerConfig includes a set of configs for chain indexers.
@@ -134,6 +135,7 @@ type ChtIndexerBackend struct {
 	section, sectionSize uint64
 	lastHash             common.Hash
 	trie                 *trie.Trie
+	originRoot           common.Hash
 }
 
 // NewChtIndexer creates a Cht chain indexer
@@ -191,6 +193,7 @@ func (c *ChtIndexerBackend) Reset(ctx context.Context, section uint64, lastSecti
 		}
 	}
 	c.section = section
+	c.originRoot = root
 	return err
 }
 
@@ -214,7 +217,7 @@ func (c *ChtIndexerBackend) Commit() error {
 	root, nodes := c.trie.Commit(false)
 	// Commit trie changes into trie database in case it's not nil.
 	if nodes != nil {
-		if err := c.triedb.Update(trie.NewWithNodeSet(nodes)); err != nil {
+		if err := c.triedb.Update(root, c.originRoot, trienode.NewWithNodeSet(nodes)); err != nil {
 			return err
 		}
 		if err := c.triedb.Commit(root, false); err != nil {
@@ -332,6 +335,7 @@ type BloomTrieIndexerBackend struct {
 	size              uint64
 	bloomTrieRatio    uint64
 	trie              *trie.Trie
+	originRoot        common.Hash
 	sectionHeads      []common.Hash
 }
 
@@ -413,6 +417,7 @@ func (b *BloomTrieIndexerBackend) Reset(ctx context.Context, section uint64, las
 		}
 	}
 	b.section = section
+	b.originRoot = root
 	return err
 }
 
@@ -463,7 +468,7 @@ func (b *BloomTrieIndexerBackend) Commit() error {
 	root, nodes := b.trie.Commit(false)
 	// Commit trie changes into trie database in case it's not nil.
 	if nodes != nil {
-		if err := b.triedb.Update(trie.NewWithNodeSet(nodes)); err != nil {
+		if err := b.triedb.Update(root, b.originRoot, trienode.NewWithNodeSet(nodes)); err != nil {
 			return err
 		}
 		if err := b.triedb.Commit(root, false); err != nil {

light/trie.go

@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 var (
@@ -156,7 +157,7 @@ func (t *odrTrie) DeleteStorage(_ common.Address, key []byte) error {
 	})
 }
 
-// TryDeleteAccount abstracts an account deletion from the trie.
+// DeleteAccount abstracts an account deletion from the trie.
 func (t *odrTrie) DeleteAccount(address common.Address) error {
 	key := crypto.Keccak256(address.Bytes())
 	return t.do(key, func() error {
@@ -164,7 +165,7 @@ func (t *odrTrie) DeleteAccount(address common.Address) error {
 	})
 }
 
-func (t *odrTrie) Commit(collectLeaf bool) (common.Hash, *trie.NodeSet) {
+func (t *odrTrie) Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet) {
 	if t.trie == nil {
 		return t.id.Root, nil
 	}

tests/fuzzers/stacktrie/trie_fuzzer.go

@@ -27,9 +27,11 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 	"golang.org/x/crypto/sha3"
 )
 
@@ -184,7 +186,7 @@ func (f *fuzzer) fuzz() int {
 	// Flush trie -> database
 	rootA, nodes := trieA.Commit(false)
 	if nodes != nil {
-		dbA.Update(trie.NewWithNodeSet(nodes))
+		dbA.Update(rootA, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	}
 	// Flush memdb -> disk (sponge)
 	dbA.Commit(rootA, false)

tests/fuzzers/trie/trie-fuzzer.go

@@ -22,7 +22,9 @@ import (
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/trie"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 // randTest performs random trie operations.
@@ -139,11 +141,12 @@ func Fuzz(input []byte) int {
 }
 
 func runRandTest(rt randTest) error {
-	triedb := trie.NewDatabase(rawdb.NewMemoryDatabase())
-
-	tr := trie.NewEmpty(triedb)
-	values := make(map[string]string) // tracks content of the trie
-
+	var (
+		triedb = trie.NewDatabase(rawdb.NewMemoryDatabase())
+		tr     = trie.NewEmpty(triedb)
+		origin = types.EmptyRootHash
+		values = make(map[string]string) // tracks content of the trie
+	)
 	for i, step := range rt {
 		switch step.op {
 		case opUpdate:
@@ -163,7 +166,7 @@ func runRandTest(rt randTest) error {
 		case opCommit:
 			hash, nodes := tr.Commit(false)
 			if nodes != nil {
-				if err := triedb.Update(trie.NewWithNodeSet(nodes)); err != nil {
+				if err := triedb.Update(hash, origin, trienode.NewWithNodeSet(nodes)); err != nil {
 					return err
 				}
 			}
@@ -172,6 +175,7 @@ func runRandTest(rt randTest) error {
 				return err
 			}
 			tr = newtr
+			origin = hash
 		case opItercheckhash:
 			checktr := trie.NewEmpty(triedb)
 			it := trie.NewIterator(tr.NodeIterator(nil))

trie/committer.go

@@ -23,23 +23,17 @@ import (
 	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
-// leaf represents a trie leaf node
-type leaf struct {
-	blob   []byte      // raw blob of leaf
-	parent common.Hash // the hash of parent node
-}
-
 // committer is the tool used for the trie Commit operation. The committer will
 // capture all dirty nodes during the commit process and keep them cached in
 // insertion order.
 type committer struct {
-	nodes       *NodeSet
+	nodes       *trienode.NodeSet
 	tracer      *tracer
 	collectLeaf bool
 }
 
 // newCommitter creates a new committer or picks one from the pool.
-func newCommitter(nodeset *NodeSet, tracer *tracer, collectLeaf bool) *committer {
+func newCommitter(nodeset *trienode.NodeSet, tracer *tracer, collectLeaf bool) *committer {
 	return &committer{
 		nodes:       nodeset,
 		tracer:      tracer,
@@ -139,7 +133,7 @@ func (c *committer) store(path []byte, n node) node {
 		// deleted only if the node was existent in database before.
 		prev, ok := c.tracer.accessList[string(path)]
 		if ok {
-			c.nodes.addNode(path, trienode.NewWithPrev(common.Hash{}, nil, prev))
+			c.nodes.AddNode(path, trienode.NewWithPrev(common.Hash{}, nil, prev))
 		}
 		return n
 	}
@@ -152,7 +146,7 @@ func (c *committer) store(path []byte, n node) node {
 			c.tracer.accessList[string(path)],
 		)
 	)
-	c.nodes.addNode(path, node)
+	c.nodes.AddNode(path, node)
 
 	// Collect the corresponding leaf node if it's required. We don't check
 	// full node since it's impossible to store value in fullNode. The key
@@ -160,7 +154,7 @@ func (c *committer) store(path []byte, n node) node {
 	if c.collectLeaf {
 		if sn, ok := n.(*shortNode); ok {
 			if val, ok := sn.Val.(valueNode); ok {
-				c.nodes.addLeaf(&leaf{blob: val, parent: nhash})
+				c.nodes.AddLeaf(nhash, val)
 			}
 		}
 	}
@@ -172,7 +166,7 @@ type mptResolver struct{}
 
 // ForEach implements childResolver, decodes the provided node and
 // traverses the children inside.
-func (resolver mptResolver) forEach(node []byte, onChild func(common.Hash)) {
+func (resolver mptResolver) ForEach(node []byte, onChild func(common.Hash)) {
 	forGatherChildren(mustDecodeNodeUnsafe(nil, node), onChild)
 }
 

trie/database_test.go

@@ -17,17 +17,19 @@
 package trie
 
 import (
-	"testing"
-
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/trie/triedb/hashdb"
 )
 
-// Tests that the trie database returns a missing trie node error if attempting
-// to retrieve the meta root.
-func TestDatabaseMetarootFetch(t *testing.T) {
-	db := NewDatabase(rawdb.NewMemoryDatabase())
-	if _, err := db.Node(common.Hash{}); err == nil {
-		t.Fatalf("metaroot retrieval succeeded")
+// newTestDatabase initializes the trie database with specified scheme.
+func newTestDatabase(diskdb ethdb.Database, scheme string) *Database {
+	db := prepare(diskdb, nil)
+	if scheme == rawdb.HashScheme {
+		db.backend = hashdb.New(diskdb, db.cleans, mptResolver{})
 	}
+	//} else {
+	//	db.backend = snap.New(diskdb, db.cleans, nil)
+	//}
+	return db
 }

trie/database_wrap.go

@@ -0,0 +1,267 @@
+// Copyright 2022 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package trie
+
+import (
+	"errors"
+	"runtime"
+	"time"
+
+	"github.com/VictoriaMetrics/fastcache"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/trie/triedb/hashdb"
+	"github.com/ethereum/go-ethereum/trie/trienode"
+)
+
+// Config defines all necessary options for database.
+type Config struct {
+	Cache     int    // Memory allowance (MB) to use for caching trie nodes in memory
+	Journal   string // Journal of clean cache to survive node restarts
+	Preimages bool   // Flag whether the preimage of trie key is recorded
+}
+
+// backend defines the methods needed to access/update trie nodes in different
+// state scheme.
+type backend interface {
+	// Scheme returns the identifier of used storage scheme.
+	Scheme() string
+
+	// Initialized returns an indicator if the state data is already initialized
+	// according to the state scheme.
+	Initialized(genesisRoot common.Hash) bool
+
+	// Size returns the current storage size of the memory cache in front of the
+	// persistent database layer.
+	Size() common.StorageSize
+
+	// Update performs a state transition by committing dirty nodes contained
+	// in the given set in order to update state from the specified parent to
+	// the specified root.
+	Update(root common.Hash, parent common.Hash, nodes *trienode.MergedNodeSet) error
+
+	// Commit writes all relevant trie nodes belonging to the specified state
+	// to disk. Report specifies whether logs will be displayed in info level.
+	Commit(root common.Hash, report bool) error
+
+	// Close closes the trie database backend and releases all held resources.
+	Close() error
+}
+
+// Database is the wrapper of the underlying backend which is shared by different
+// types of node backend as an entrypoint. It's responsible for all interactions
+// relevant with trie nodes and node preimages.
+type Database struct {
+	config    *Config          // Configuration for trie database
+	diskdb    ethdb.Database   // Persistent database to store the snapshot
+	cleans    *fastcache.Cache // Megabytes permitted using for read caches
+	preimages *preimageStore   // The store for caching preimages
+	backend   backend          // The backend for managing trie nodes
+}
+
+// prepare initializes the database with provided configs, but the
+// database backend is still left as nil.
+func prepare(diskdb ethdb.Database, config *Config) *Database {
+	var cleans *fastcache.Cache
+	if config != nil && config.Cache > 0 {
+		if config.Journal == "" {
+			cleans = fastcache.New(config.Cache * 1024 * 1024)
+		} else {
+			cleans = fastcache.LoadFromFileOrNew(config.Journal, config.Cache*1024*1024)
+		}
+	}
+	var preimages *preimageStore
+	if config != nil && config.Preimages {
+		preimages = newPreimageStore(diskdb)
+	}
+	return &Database{
+		config:    config,
+		diskdb:    diskdb,
+		cleans:    cleans,
+		preimages: preimages,
+	}
+}
+
+// NewDatabase initializes the trie database with default settings, namely
+// the legacy hash-based scheme is used by default.
+func NewDatabase(diskdb ethdb.Database) *Database {
+	return NewDatabaseWithConfig(diskdb, nil)
+}
+
+// NewDatabaseWithConfig initializes the trie database with provided configs.
+// The path-based scheme is not activated yet, always initialized with legacy
+// hash-based scheme by default.
+func NewDatabaseWithConfig(diskdb ethdb.Database, config *Config) *Database {
+	db := prepare(diskdb, config)
+	db.backend = hashdb.New(diskdb, db.cleans, mptResolver{})
+	return db
+}
+
+// Reader returns a reader for accessing all trie nodes with provided state root.
+// Nil is returned in case the state is not available.
+func (db *Database) Reader(blockRoot common.Hash) Reader {
+	return db.backend.(*hashdb.Database).Reader(blockRoot)
+}
+
+// Update performs a state transition by committing dirty nodes contained in the
+// given set in order to update state from the specified parent to the specified
+// root. The held pre-images accumulated up to this point will be flushed in case
+// the size exceeds the threshold.
+func (db *Database) Update(root common.Hash, parent common.Hash, nodes *trienode.MergedNodeSet) error {
+	if db.preimages != nil {
+		db.preimages.commit(false)
+	}
+	return db.backend.Update(root, parent, nodes)
+}
+
+// Commit iterates over all the children of a particular node, writes them out
+// to disk. As a side effect, all pre-images accumulated up to this point are
+// also written.
+func (db *Database) Commit(root common.Hash, report bool) error {
+	if db.preimages != nil {
+		db.preimages.commit(true)
+	}
+	return db.backend.Commit(root, report)
+}
+
+// Size returns the storage size of dirty trie nodes in front of the persistent
+// database and the size of cached preimages.
+func (db *Database) Size() (common.StorageSize, common.StorageSize) {
+	var (
+		storages  common.StorageSize
+		preimages common.StorageSize
+	)
+	storages = db.backend.Size()
+	if db.preimages != nil {
+		preimages = db.preimages.size()
+	}
+	return storages, preimages
+}
+
+// Initialized returns an indicator if the state data is already initialized
+// according to the state scheme.
+func (db *Database) Initialized(genesisRoot common.Hash) bool {
+	return db.backend.Initialized(genesisRoot)
+}
+
+// Scheme returns the node scheme used in the database.
+func (db *Database) Scheme() string {
+	return db.backend.Scheme()
+}
+
+// Close flushes the dangling preimages to disk and closes the trie database.
+// It is meant to be called when closing the blockchain object, so that all
+// resources held can be released correctly.
+func (db *Database) Close() error {
+	if db.preimages != nil {
+		db.preimages.commit(true)
+	}
+	return db.backend.Close()
+}
+
+// saveCache saves clean state cache to given directory path
+// using specified CPU cores.
+func (db *Database) saveCache(dir string, threads int) error {
+	if db.cleans == nil {
+		return nil
+	}
+	log.Info("Writing clean trie cache to disk", "path", dir, "threads", threads)
+
+	start := time.Now()
+	err := db.cleans.SaveToFileConcurrent(dir, threads)
+	if err != nil {
+		log.Error("Failed to persist clean trie cache", "error", err)
+		return err
+	}
+	log.Info("Persisted the clean trie cache", "path", dir, "elapsed", common.PrettyDuration(time.Since(start)))
+	return nil
+}
+
+// SaveCache atomically saves fast cache data to the given dir using all
+// available CPU cores.
+func (db *Database) SaveCache(dir string) error {
+	return db.saveCache(dir, runtime.GOMAXPROCS(0))
+}
+
+// SaveCachePeriodically atomically saves fast cache data to the given dir with
+// the specified interval. All dump operation will only use a single CPU core.
+func (db *Database) SaveCachePeriodically(dir string, interval time.Duration, stopCh <-chan struct{}) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			db.saveCache(dir, 1)
+		case <-stopCh:
+			return
+		}
+	}
+}
+
+// Cap iteratively flushes old but still referenced trie nodes until the total
+// memory usage goes below the given threshold. The held pre-images accumulated
+// up to this point will be flushed in case the size exceeds the threshold.
+//
+// It's only supported by hash-based database and will return an error for others.
+func (db *Database) Cap(limit common.StorageSize) error {
+	hdb, ok := db.backend.(*hashdb.Database)
+	if !ok {
+		return errors.New("not supported")
+	}
+	if db.preimages != nil {
+		db.preimages.commit(false)
+	}
+	return hdb.Cap(limit)
+}
+
+// Reference adds a new reference from a parent node to a child node. This function
+// is used to add reference between internal trie node and external node(e.g. storage
+// trie root), all internal trie nodes are referenced together by database itself.
+//
+// It's only supported by hash-based database and will return an error for others.
+func (db *Database) Reference(root common.Hash, parent common.Hash) error {
+	hdb, ok := db.backend.(*hashdb.Database)
+	if !ok {
+		return errors.New("not supported")
+	}
+	hdb.Reference(root, parent)
+	return nil
+}
+
+// Dereference removes an existing reference from a root node. It's only
+// supported by hash-based database and will return an error for others.
+func (db *Database) Dereference(root common.Hash) error {
+	hdb, ok := db.backend.(*hashdb.Database)
+	if !ok {
+		return errors.New("not supported")
+	}
+	hdb.Dereference(root)
+	return nil
+}
+
+// Node retrieves the rlp-encoded node blob with provided node hash. It's
+// only supported by hash-based database and will return an error for others.
+// Note, this function should be deprecated once ETH66 is deprecated.
+func (db *Database) Node(hash common.Hash) ([]byte, error) {
+	hdb, ok := db.backend.(*hashdb.Database)
+	if !ok {
+		return nil, errors.New("not supported")
+	}
+	return hdb.Node(hash)
+}

trie/iterator_test.go

@@ -25,9 +25,11 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 func TestEmptyIterator(t *testing.T) {
@@ -61,7 +63,7 @@ func TestIterator(t *testing.T) {
 		trie.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	root, nodes := trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	trie, _ = New(TrieID(root), db)
 	found := make(map[string]string)
@@ -115,39 +117,61 @@ func TestIteratorLargeData(t *testing.T) {
 	}
 }
 
+type iterationElement struct {
+	hash common.Hash
+	path []byte
+	blob []byte
+}
+
 // Tests that the node iterator indeed walks over the entire database contents.
 func TestNodeIteratorCoverage(t *testing.T) {
+	testNodeIteratorCoverage(t, rawdb.HashScheme)
+	//testNodeIteratorCoverage(t, rawdb.PathScheme)
+}
+
+func testNodeIteratorCoverage(t *testing.T, scheme string) {
 	// Create some arbitrary test trie to iterate
-	db, trie, _ := makeTestTrie()
+	db, nodeDb, trie, _ := makeTestTrie(scheme)
 
 	// Gather all the node hashes found by the iterator
-	hashes := make(map[common.Hash]struct{})
+	var elements = make(map[common.Hash]iterationElement)
 	for it := trie.NodeIterator(nil); it.Next(true); {
 		if it.Hash() != (common.Hash{}) {
-			hashes[it.Hash()] = struct{}{}
+			elements[it.Hash()] = iterationElement{
+				hash: it.Hash(),
+				path: common.CopyBytes(it.Path()),
+				blob: common.CopyBytes(it.NodeBlob()),
+			}
 		}
 	}
 	// Cross check the hashes and the database itself
-	for hash := range hashes {
-		if _, err := db.Node(hash); err != nil {
-			t.Errorf("failed to retrieve reported node %x: %v", hash, err)
+	for _, element := range elements {
+		if blob, err := nodeDb.Reader(trie.Hash()).Node(common.Hash{}, element.path, element.hash); err != nil {
+			t.Errorf("failed to retrieve reported node %x: %v", element.hash, err)
+		} else if !bytes.Equal(blob, element.blob) {
+			t.Errorf("node blob is different, want %v got %v", element.blob, blob)
 		}
 	}
-	for hash, obj := range db.dirties {
-		if obj != nil && hash != (common.Hash{}) {
-			if _, ok := hashes[hash]; !ok {
-				t.Errorf("state entry not reported %x", hash)
-			}
-		}
-	}
-	it := db.diskdb.NewIterator(nil, nil)
+	var (
+		count int
+		it    = db.NewIterator(nil, nil)
+	)
 	for it.Next() {
-		key := it.Key()
-		if _, ok := hashes[common.BytesToHash(key)]; !ok {
-			t.Errorf("state entry not reported %x", key)
+		res, _, _ := isTrieNode(nodeDb.Scheme(), it.Key(), it.Value())
+		if !res {
+			continue
+		}
+		count += 1
+		if elem, ok := elements[crypto.Keccak256Hash(it.Value())]; !ok {
+			t.Error("state entry not reported")
+		} else if !bytes.Equal(it.Value(), elem.blob) {
+			t.Errorf("node blob is different, want %v got %v", elem.blob, it.Value())
 		}
 	}
 	it.Release()
+	if count != len(elements) {
+		t.Errorf("state entry is mismatched %d %d", count, len(elements))
+	}
 }
 
 type kvs struct{ k, v string }
@@ -223,7 +247,7 @@ func TestDifferenceIterator(t *testing.T) {
 		triea.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	rootA, nodesA := triea.Commit(false)
-	dba.Update(NewWithNodeSet(nodesA))
+	dba.Update(rootA, types.EmptyRootHash, trienode.NewWithNodeSet(nodesA))
 	triea, _ = New(TrieID(rootA), dba)
 
 	dbb := NewDatabase(rawdb.NewMemoryDatabase())
@@ -232,7 +256,7 @@ func TestDifferenceIterator(t *testing.T) {
 		trieb.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	rootB, nodesB := trieb.Commit(false)
-	dbb.Update(NewWithNodeSet(nodesB))
+	dbb.Update(rootB, types.EmptyRootHash, trienode.NewWithNodeSet(nodesB))
 	trieb, _ = New(TrieID(rootB), dbb)
 
 	found := make(map[string]string)
@@ -265,7 +289,7 @@ func TestUnionIterator(t *testing.T) {
 		triea.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	rootA, nodesA := triea.Commit(false)
-	dba.Update(NewWithNodeSet(nodesA))
+	dba.Update(rootA, types.EmptyRootHash, trienode.NewWithNodeSet(nodesA))
 	triea, _ = New(TrieID(rootA), dba)
 
 	dbb := NewDatabase(rawdb.NewMemoryDatabase())
@@ -274,7 +298,7 @@ func TestUnionIterator(t *testing.T) {
 		trieb.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	rootB, nodesB := trieb.Commit(false)
-	dbb.Update(NewWithNodeSet(nodesB))
+	dbb.Update(rootB, types.EmptyRootHash, trienode.NewWithNodeSet(nodesB))
 	trieb, _ = New(TrieID(rootB), dbb)
 
 	di, _ := NewUnionIterator([]NodeIterator{triea.NodeIterator(nil), trieb.NodeIterator(nil)})
@@ -320,79 +344,98 @@ func TestIteratorNoDups(t *testing.T) {
 }
 
 // This test checks that nodeIterator.Next can be retried after inserting missing trie nodes.
-func TestIteratorContinueAfterErrorDisk(t *testing.T)    { testIteratorContinueAfterError(t, false) }
-func TestIteratorContinueAfterErrorMemonly(t *testing.T) { testIteratorContinueAfterError(t, true) }
+func TestIteratorContinueAfterError(t *testing.T) {
+	testIteratorContinueAfterError(t, false, rawdb.HashScheme)
+	testIteratorContinueAfterError(t, true, rawdb.HashScheme)
+	// testIteratorContinueAfterError(t, false, rawdb.PathScheme)
+	// testIteratorContinueAfterError(t, true, rawdb.PathScheme)
+}
 
-func testIteratorContinueAfterError(t *testing.T, memonly bool) {
+func testIteratorContinueAfterError(t *testing.T, memonly bool, scheme string) {
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
+	tdb := newTestDatabase(diskdb, scheme)
 
-	tr := NewEmpty(triedb)
+	tr := NewEmpty(tdb)
 	for _, val := range testdata1 {
 		tr.MustUpdate([]byte(val.k), []byte(val.v))
 	}
-	_, nodes := tr.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
+	root, nodes := tr.Commit(false)
+	tdb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	if !memonly {
-		triedb.Commit(tr.Hash(), false)
+		tdb.Commit(root, false)
 	}
+	tr, _ = New(TrieID(root), tdb)
 	wantNodeCount := checkIteratorNoDups(t, tr.NodeIterator(nil), nil)
 
 	var (
-		diskKeys [][]byte
-		memKeys  []common.Hash
+		paths  [][]byte
+		hashes []common.Hash
 	)
 	if memonly {
-		memKeys = triedb.Nodes()
+		for path, n := range nodes.Nodes {
+			paths = append(paths, []byte(path))
+			hashes = append(hashes, n.Hash)
+		}
 	} else {
 		it := diskdb.NewIterator(nil, nil)
 		for it.Next() {
-			diskKeys = append(diskKeys, it.Key())
+			ok, path, hash := isTrieNode(tdb.Scheme(), it.Key(), it.Value())
+			if !ok {
+				continue
+			}
+			paths = append(paths, path)
+			hashes = append(hashes, hash)
 		}
 		it.Release()
 	}
 	for i := 0; i < 20; i++ {
 		// Create trie that will load all nodes from DB.
-		tr, _ := New(TrieID(tr.Hash()), triedb)
+		tr, _ := New(TrieID(tr.Hash()), tdb)
 
 		// Remove a random node from the database. It can't be the root node
 		// because that one is already loaded.
 		var (
-			rkey common.Hash
 			rval  []byte
-			robj *cachedNode
+			rpath []byte
+			rhash common.Hash
 		)
 		for {
 			if memonly {
-				rkey = memKeys[rand.Intn(len(memKeys))]
-			} else {
-				copy(rkey[:], diskKeys[rand.Intn(len(diskKeys))])
+				rpath = paths[rand.Intn(len(paths))]
+				n := nodes.Nodes[string(rpath)]
+				if n == nil {
+					continue
 				}
-			if rkey != tr.Hash() {
+				rhash = n.Hash
+			} else {
+				index := rand.Intn(len(paths))
+				rpath = paths[index]
+				rhash = hashes[index]
+			}
+			if rhash != tr.Hash() {
 				break
 			}
 		}
 		if memonly {
-			robj = triedb.dirties[rkey]
-			delete(triedb.dirties, rkey)
+			tr.reader.banned = map[string]struct{}{string(rpath): {}}
 		} else {
-			rval, _ = diskdb.Get(rkey[:])
-			diskdb.Delete(rkey[:])
+			rval = rawdb.ReadTrieNode(diskdb, common.Hash{}, rpath, rhash, tdb.Scheme())
+			rawdb.DeleteTrieNode(diskdb, common.Hash{}, rpath, rhash, tdb.Scheme())
 		}
 		// Iterate until the error is hit.
 		seen := make(map[string]bool)
 		it := tr.NodeIterator(nil)
 		checkIteratorNoDups(t, it, seen)
 		missing, ok := it.Error().(*MissingNodeError)
-		if !ok || missing.NodeHash != rkey {
+		if !ok || missing.NodeHash != rhash {
 			t.Fatal("didn't hit missing node, got", it.Error())
 		}
 
 		// Add the node back and continue iteration.
 		if memonly {
-			triedb.dirties[rkey] = robj
+			delete(tr.reader.banned, string(rpath))
 		} else {
-			diskdb.Put(rkey[:], rval)
+			rawdb.WriteTrieNode(diskdb, common.Hash{}, rpath, rhash, rval, tdb.Scheme())
 		}
 		checkIteratorNoDups(t, it, seen)
 		if it.Error() != nil {
@@ -407,42 +450,48 @@ func testIteratorContinueAfterError(t *testing.T, memonly bool) {
 // Similar to the test above, this one checks that failure to create nodeIterator at a
 // certain key prefix behaves correctly when Next is called. The expectation is that Next
 // should retry seeking before returning true for the first time.
-func TestIteratorContinueAfterSeekErrorDisk(t *testing.T) {
-	testIteratorContinueAfterSeekError(t, false)
-}
-func TestIteratorContinueAfterSeekErrorMemonly(t *testing.T) {
-	testIteratorContinueAfterSeekError(t, true)
+func TestIteratorContinueAfterSeekError(t *testing.T) {
+	testIteratorContinueAfterSeekError(t, false, rawdb.HashScheme)
+	testIteratorContinueAfterSeekError(t, true, rawdb.HashScheme)
+	// testIteratorContinueAfterSeekError(t, false, rawdb.PathScheme)
+	// testIteratorContinueAfterSeekError(t, true, rawdb.PathScheme)
 }
 
-func testIteratorContinueAfterSeekError(t *testing.T, memonly bool) {
+func testIteratorContinueAfterSeekError(t *testing.T, memonly bool, scheme string) {
 	// Commit test trie to db, then remove the node containing "bars".
+	var (
+		barNodePath []byte
+		barNodeHash = common.HexToHash("05041990364eb72fcb1127652ce40d8bab765f2bfe53225b1170d276cc101c2e")
+	)
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
-
+	triedb := newTestDatabase(diskdb, scheme)
 	ctr := NewEmpty(triedb)
 	for _, val := range testdata1 {
 		ctr.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	root, nodes := ctr.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
+	for path, n := range nodes.Nodes {
+		if n.Hash == barNodeHash {
+			barNodePath = []byte(path)
+			break
+		}
+	}
+	triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	if !memonly {
 		triedb.Commit(root, false)
 	}
-	barNodeHash := common.HexToHash("05041990364eb72fcb1127652ce40d8bab765f2bfe53225b1170d276cc101c2e")
 	var (
 		barNodeBlob []byte
-		barNodeObj  *cachedNode
 	)
+	tr, _ := New(TrieID(root), triedb)
 	if memonly {
-		barNodeObj = triedb.dirties[barNodeHash]
-		delete(triedb.dirties, barNodeHash)
+		tr.reader.banned = map[string]struct{}{string(barNodePath): {}}
 	} else {
-		barNodeBlob, _ = diskdb.Get(barNodeHash[:])
-		diskdb.Delete(barNodeHash[:])
+		barNodeBlob = rawdb.ReadTrieNode(diskdb, common.Hash{}, barNodePath, barNodeHash, triedb.Scheme())
+		rawdb.DeleteTrieNode(diskdb, common.Hash{}, barNodePath, barNodeHash, triedb.Scheme())
 	}
 	// Create a new iterator that seeks to "bars". Seeking can't proceed because
 	// the node is missing.
-	tr, _ := New(TrieID(root), triedb)
 	it := tr.NodeIterator([]byte("bars"))
 	missing, ok := it.Error().(*MissingNodeError)
 	if !ok {
@@ -452,9 +501,9 @@ func testIteratorContinueAfterSeekError(t *testing.T, memonly bool) {
 	}
 	// Reinsert the missing node.
 	if memonly {
-		triedb.dirties[barNodeHash] = barNodeObj
+		delete(tr.reader.banned, string(barNodePath))
 	} else {
-		diskdb.Put(barNodeHash[:], barNodeBlob)
+		rawdb.WriteTrieNode(diskdb, common.Hash{}, barNodePath, barNodeHash, barNodeBlob, triedb.Scheme())
 	}
 	// Check that iteration produces the right set of values.
 	if err := checkIteratorOrder(testdata1[2:], NewIterator(it)); err != nil {
@@ -475,6 +524,11 @@ func checkIteratorNoDups(t *testing.T, it NodeIterator, seen map[string]bool) in
 	return len(seen)
 }
 
+func TestIteratorNodeBlob(t *testing.T) {
+	testIteratorNodeBlob(t, rawdb.HashScheme)
+	//testIteratorNodeBlob(t, rawdb.PathScheme)
+}
+
 type loggingDb struct {
 	getCount uint64
 	backend  ethdb.KeyValueStore
@@ -542,8 +596,8 @@ func makeLargeTestTrie() (*Database, *StateTrie, *loggingDb) {
 		val = crypto.Keccak256(val)
 		trie.MustUpdate(key, val)
 	}
-	_, nodes := trie.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
+	root, nodes := trie.Commit(false)
+	triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	// Return the generated trie
 	return triedb, trie, logDb
 }
@@ -562,10 +616,10 @@ func TestNodeIteratorLargeTrie(t *testing.T) {
 	}
 }
 
-func TestIteratorNodeBlob(t *testing.T) {
+func testIteratorNodeBlob(t *testing.T, scheme string) {
 	var (
 		db     = rawdb.NewMemoryDatabase()
-		triedb = NewDatabase(db)
+		triedb = newTestDatabase(db, scheme)
 		trie   = NewEmpty(triedb)
 	)
 	vals := []struct{ k, v string }{
@@ -582,11 +636,12 @@ func TestIteratorNodeBlob(t *testing.T) {
 		all[val.k] = val.v
 		trie.MustUpdate([]byte(val.k), []byte(val.v))
 	}
-	_, nodes := trie.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
-	triedb.Cap(0)
+	root, nodes := trie.Commit(false)
+	triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
+	triedb.Commit(root, false)
 
-	found := make(map[common.Hash][]byte)
+	var found = make(map[common.Hash][]byte)
+	trie, _ = New(TrieID(root), triedb)
 	it := trie.NodeIterator(nil)
 	for it.Next(true) {
 		if it.Hash() == (common.Hash{}) {
@@ -600,9 +655,13 @@ func TestIteratorNodeBlob(t *testing.T) {
 
 	var count int
 	for dbIter.Next() {
-		got, present := found[common.BytesToHash(dbIter.Key())]
+		ok, _, _ := isTrieNode(triedb.Scheme(), dbIter.Key(), dbIter.Value())
+		if !ok {
+			continue
+		}
+		got, present := found[crypto.Keccak256Hash(dbIter.Value())]
 		if !present {
-			t.Fatalf("Miss trie node %v", dbIter.Key())
+			t.Fatal("Miss trie node")
 		}
 		if !bytes.Equal(got, dbIter.Value()) {
 			t.Fatalf("Unexpected trie node want %v got %v", dbIter.Value(), got)
@@ -613,3 +672,29 @@ func TestIteratorNodeBlob(t *testing.T) {
 		t.Fatal("Find extra trie node via iterator")
 	}
 }
+
+// isTrieNode is a helper function which reports if the provided
+// database entry belongs to a trie node or not. Note in tests
+// only single layer trie is used, namely storage trie is not
+// considered at all.
+func isTrieNode(scheme string, key, val []byte) (bool, []byte, common.Hash) {
+	var (
+		path []byte
+		hash common.Hash
+	)
+	if scheme == rawdb.HashScheme {
+		ok := rawdb.IsLegacyTrieNode(key, val)
+		if !ok {
+			return false, nil, common.Hash{}
+		}
+		hash = common.BytesToHash(key)
+	} else {
+		ok, remain := rawdb.IsAccountTrieNode(key)
+		if !ok {
+			return false, nil, common.Hash{}
+		}
+		path = common.CopyBytes(remain)
+		hash = crypto.Keccak256Hash(val)
+	}
+	return true, path, hash
+}

trie/nodeset.go

@@ -1,149 +0,0 @@
-// Copyright 2022 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package trie
-
-import (
-	"fmt"
-	"sort"
-	"strings"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/trie/trienode"
-)
-
-// NodeSet contains all dirty nodes collected during the commit operation.
-// Each node is keyed by path. It's not thread-safe to use.
-type NodeSet struct {
-	owner   common.Hash // the identifier of the trie
-	leaves  []*leaf     // the list of dirty leaves
-	updates int         // the count of updated and inserted nodes
-	deletes int         // the count of deleted nodes
-
-	// The set of all dirty nodes. Dirty nodes include newly inserted nodes,
-	// deleted nodes and updated nodes. The original value of the newly
-	// inserted node must be nil, and the original value of the other two
-	// types must be non-nil.
-	nodes map[string]*trienode.WithPrev
-}
-
-// NewNodeSet initializes an empty node set to be used for tracking dirty nodes
-// from a specific account or storage trie. The owner is zero for the account
-// trie and the owning account address hash for storage tries.
-func NewNodeSet(owner common.Hash) *NodeSet {
-	return &NodeSet{
-		owner: owner,
-		nodes: make(map[string]*trienode.WithPrev),
-	}
-}
-
-// forEachWithOrder iterates the dirty nodes with the order from bottom to top,
-// right to left, nodes with the longest path will be iterated first.
-func (set *NodeSet) forEachWithOrder(callback func(path string, n *trienode.Node)) {
-	var paths sort.StringSlice
-	for path := range set.nodes {
-		paths = append(paths, path)
-	}
-	// Bottom-up, longest path first
-	sort.Sort(sort.Reverse(paths))
-	for _, path := range paths {
-		callback(path, set.nodes[path].Unwrap())
-	}
-}
-
-// addNode adds the provided dirty node into set.
-func (set *NodeSet) addNode(path []byte, n *trienode.WithPrev) {
-	if n.IsDeleted() {
-		set.deletes += 1
-	} else {
-		set.updates += 1
-	}
-	set.nodes[string(path)] = n
-}
-
-// addLeaf adds the provided leaf node into set.
-func (set *NodeSet) addLeaf(node *leaf) {
-	set.leaves = append(set.leaves, node)
-}
-
-// Size returns the number of dirty nodes in set.
-func (set *NodeSet) Size() (int, int) {
-	return set.updates, set.deletes
-}
-
-// Hashes returns the hashes of all updated nodes. TODO(rjl493456442) how can
-// we get rid of it?
-func (set *NodeSet) Hashes() []common.Hash {
-	var ret []common.Hash
-	for _, node := range set.nodes {
-		ret = append(ret, node.Hash)
-	}
-	return ret
-}
-
-// Summary returns a string-representation of the NodeSet.
-func (set *NodeSet) Summary() string {
-	var out = new(strings.Builder)
-	fmt.Fprintf(out, "nodeset owner: %v\n", set.owner)
-	if set.nodes != nil {
-		for path, n := range set.nodes {
-			// Deletion
-			if n.IsDeleted() {
-				fmt.Fprintf(out, "  [-]: %x prev: %x\n", path, n.Prev)
-				continue
-			}
-			// Insertion
-			if len(n.Prev) == 0 {
-				fmt.Fprintf(out, "  [+]: %x -> %v\n", path, n.Hash)
-				continue
-			}
-			// Update
-			fmt.Fprintf(out, "  [*]: %x -> %v prev: %x\n", path, n.Hash, n.Prev)
-		}
-	}
-	for _, n := range set.leaves {
-		fmt.Fprintf(out, "[leaf]: %v\n", n)
-	}
-	return out.String()
-}
-
-// MergedNodeSet represents a merged dirty node set for a group of tries.
-type MergedNodeSet struct {
-	sets map[common.Hash]*NodeSet
-}
-
-// NewMergedNodeSet initializes an empty merged set.
-func NewMergedNodeSet() *MergedNodeSet {
-	return &MergedNodeSet{sets: make(map[common.Hash]*NodeSet)}
-}
-
-// NewWithNodeSet constructs a merged nodeset with the provided single set.
-func NewWithNodeSet(set *NodeSet) *MergedNodeSet {
-	merged := NewMergedNodeSet()
-	merged.Merge(set)
-	return merged
-}
-
-// Merge merges the provided dirty nodes of a trie into the set. The assumption
-// is held that no duplicated set belonging to the same trie will be merged twice.
-func (set *MergedNodeSet) Merge(other *NodeSet) error {
-	_, present := set.sets[other.owner]
-	if present {
-		return fmt.Errorf("duplicate trie for owner %#x", other.owner)
-	}
-	set.sets[other.owner] = other
-	return nil
-}

trie/secure_trie.go

@@ -20,6 +20,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 // SecureTrie is the old name of StateTrie.
@@ -212,7 +213,7 @@ func (t *StateTrie) GetKey(shaKey []byte) []byte {
 // All cached preimages will be also flushed if preimages recording is enabled.
 // Once the trie is committed, it's not usable anymore. A new trie must
 // be created with new root and updated trie database for following usage
-func (t *StateTrie) Commit(collectLeaf bool) (common.Hash, *NodeSet) {
+func (t *StateTrie) Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet) {
 	// Write all the pre-images to the actual disk database
 	if len(t.getSecKeyCache()) > 0 {
 		if t.preimages != nil {

trie/secure_trie_test.go

@@ -25,7 +25,9 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 func newEmptySecure() *StateTrie {
@@ -59,7 +61,7 @@ func makeTestStateTrie() (*Database, *StateTrie, map[string][]byte) {
 		}
 	}
 	root, nodes := trie.Commit(false)
-	if err := triedb.Update(NewWithNodeSet(nodes)); err != nil {
+	if err := triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes)); err != nil {
 		panic(fmt.Errorf("failed to commit db %v", err))
 	}
 	// Re-create the trie based on the new state

trie/sync_test.go

@@ -25,13 +25,16 @@ import (
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 // makeTestTrie create a sample test trie to test node-wise reconstruction.
-func makeTestTrie() (*Database, *StateTrie, map[string][]byte) {
+func makeTestTrie(scheme string) (ethdb.Database, *Database, *StateTrie, map[string][]byte) {
 	// Create an empty trie
-	triedb := NewDatabase(rawdb.NewMemoryDatabase())
+	db := rawdb.NewMemoryDatabase()
+	triedb := newTestDatabase(db, scheme)
 	trie, _ := NewStateTrie(TrieID(common.Hash{}), triedb)
 
 	// Fill it with some arbitrary data
@@ -54,23 +57,27 @@ func makeTestTrie() (*Database, *StateTrie, map[string][]byte) {
 		}
 	}
 	root, nodes := trie.Commit(false)
-	if err := triedb.Update(NewWithNodeSet(nodes)); err != nil {
+	if err := triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes)); err != nil {
 		panic(fmt.Errorf("failed to commit db %v", err))
 	}
+	if err := triedb.Commit(root, false); err != nil {
+		panic(err)
+	}
 	// Re-create the trie based on the new state
 	trie, _ = NewStateTrie(TrieID(root), triedb)
-	return triedb, trie, content
+	return db, triedb, trie, content
 }
 
 // checkTrieContents cross references a reconstructed trie with an expected data
 // content map.
-func checkTrieContents(t *testing.T, db *Database, root []byte, content map[string][]byte) {
+func checkTrieContents(t *testing.T, db ethdb.Database, scheme string, root []byte, content map[string][]byte) {
 	// Check root availability and trie contents
-	trie, err := NewStateTrie(TrieID(common.BytesToHash(root)), db)
+	ndb := newTestDatabase(db, scheme)
+	trie, err := NewStateTrie(TrieID(common.BytesToHash(root)), ndb)
 	if err != nil {
 		t.Fatalf("failed to create trie at %x: %v", root, err)
 	}
-	if err := checkTrieConsistency(db, common.BytesToHash(root)); err != nil {
+	if err := checkTrieConsistency(db, scheme, common.BytesToHash(root)); err != nil {
 		t.Fatalf("inconsistent trie at %x: %v", root, err)
 	}
 	for key, val := range content {
@@ -81,9 +88,9 @@ func checkTrieContents(t *testing.T, db *Database, root []byte, content map[stri
 }
 
 // checkTrieConsistency checks that all nodes in a trie are indeed present.
-func checkTrieConsistency(db *Database, root common.Hash) error {
-	// Create and iterate a trie rooted in a subnode
-	trie, err := NewStateTrie(TrieID(root), db)
+func checkTrieConsistency(db ethdb.Database, scheme string, root common.Hash) error {
+	ndb := newTestDatabase(db, scheme)
+	trie, err := NewStateTrie(TrieID(root), ndb)
 	if err != nil {
 		return nil // Consider a non existent state consistent
 	}
@@ -104,11 +111,16 @@ type trieElement struct {
 func TestEmptySync(t *testing.T) {
 	dbA := NewDatabase(rawdb.NewMemoryDatabase())
 	dbB := NewDatabase(rawdb.NewMemoryDatabase())
-	emptyA, _ := New(TrieID(common.Hash{}), dbA)
-	emptyB, _ := New(TrieID(types.EmptyRootHash), dbB)
+	//dbC := newTestDatabase(rawdb.NewMemoryDatabase(), rawdb.PathScheme)
+	//dbD := newTestDatabase(rawdb.NewMemoryDatabase(), rawdb.PathScheme)
 
-	for i, trie := range []*Trie{emptyA, emptyB} {
-		sync := NewSync(trie.Hash(), memorydb.New(), nil, []*Database{dbA, dbB}[i].Scheme())
+	emptyA := NewEmpty(dbA)
+	emptyB, _ := New(TrieID(types.EmptyRootHash), dbB)
+	//emptyC := NewEmpty(dbC)
+	//emptyD, _ := New(TrieID(types.EmptyRootHash), dbD)
+
+	for i, trie := range []*Trie{emptyA, emptyB /*emptyC, emptyD*/} {
+		sync := NewSync(trie.Hash(), memorydb.New(), nil, []*Database{dbA, dbB /*dbC, dbD*/}[i].Scheme())
 		if paths, nodes, codes := sync.Missing(1); len(paths) != 0 || len(nodes) != 0 || len(codes) != 0 {
 			t.Errorf("test %d: content requested for empty trie: %v, %v, %v", i, paths, nodes, codes)
 		}
@@ -117,18 +129,23 @@ func TestEmptySync(t *testing.T) {
 
 // Tests that given a root hash, a trie can sync iteratively on a single thread,
 // requesting retrieval tasks and returning all of them in one go.
-func TestIterativeSyncIndividual(t *testing.T)       { testIterativeSync(t, 1, false) }
-func TestIterativeSyncBatched(t *testing.T)          { testIterativeSync(t, 100, false) }
-func TestIterativeSyncIndividualByPath(t *testing.T) { testIterativeSync(t, 1, true) }
-func TestIterativeSyncBatchedByPath(t *testing.T)    { testIterativeSync(t, 100, true) }
+func TestIterativeSync(t *testing.T) {
+	testIterativeSync(t, 1, false, rawdb.HashScheme)
+	testIterativeSync(t, 100, false, rawdb.HashScheme)
+	testIterativeSync(t, 1, true, rawdb.HashScheme)
+	testIterativeSync(t, 100, true, rawdb.HashScheme)
+	// testIterativeSync(t, 1, false, rawdb.PathScheme)
+	// testIterativeSync(t, 100, false, rawdb.PathScheme)
+	// testIterativeSync(t, 1, true, rawdb.PathScheme)
+	// testIterativeSync(t, 100, true, rawdb.PathScheme)
+}
 
-func testIterativeSync(t *testing.T, count int, bypath bool) {
+func testIterativeSync(t *testing.T, count int, bypath bool, scheme string) {
 	// Create a random trie to copy
-	srcDb, srcTrie, srcData := makeTestTrie()
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
@@ -146,7 +163,8 @@ func testIterativeSync(t *testing.T, count int, bypath bool) {
 		results := make([]NodeSyncResult, len(elements))
 		if !bypath {
 			for i, element := range elements {
-				data, err := srcDb.Node(element.hash)
+				owner, inner := ResolvePath([]byte(element.path))
+				data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 				if err != nil {
 					t.Fatalf("failed to retrieve node data for hash %x: %v", element.hash, err)
 				}
@@ -183,18 +201,22 @@ func testIterativeSync(t *testing.T, count int, bypath bool) {
 		}
 	}
 	// Cross check that the two tries are in sync
-	checkTrieContents(t, triedb, srcTrie.Hash().Bytes(), srcData)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
 }
 
 // Tests that the trie scheduler can correctly reconstruct the state even if only
 // partial results are returned, and the others sent only later.
 func TestIterativeDelayedSync(t *testing.T) {
+	testIterativeDelayedSync(t, rawdb.HashScheme)
+	//testIterativeDelayedSync(t, rawdb.PathScheme)
+}
+
+func testIterativeDelayedSync(t *testing.T, scheme string) {
 	// Create a random trie to copy
-	srcDb, srcTrie, srcData := makeTestTrie()
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
@@ -212,7 +234,8 @@ func TestIterativeDelayedSync(t *testing.T) {
 		// Sync only half of the scheduled nodes
 		results := make([]NodeSyncResult, len(elements)/2+1)
 		for i, element := range elements[:len(results)] {
-			data, err := srcDb.Node(element.hash)
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 			if err != nil {
 				t.Fatalf("failed to retrieve node data for %x: %v", element.hash, err)
 			}
@@ -240,22 +263,25 @@ func TestIterativeDelayedSync(t *testing.T) {
 		}
 	}
 	// Cross check that the two tries are in sync
-	checkTrieContents(t, triedb, srcTrie.Hash().Bytes(), srcData)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
 }
 
 // Tests that given a root hash, a trie can sync iteratively on a single thread,
 // requesting retrieval tasks and returning all of them in one go, however in a
 // random order.
-func TestIterativeRandomSyncIndividual(t *testing.T) { testIterativeRandomSync(t, 1) }
-func TestIterativeRandomSyncBatched(t *testing.T)    { testIterativeRandomSync(t, 100) }
+func TestIterativeRandomSyncIndividual(t *testing.T) {
+	testIterativeRandomSync(t, 1, rawdb.HashScheme)
+	testIterativeRandomSync(t, 100, rawdb.HashScheme)
+	// testIterativeRandomSync(t, 1, rawdb.PathScheme)
+	// testIterativeRandomSync(t, 100, rawdb.PathScheme)
+}
 
-func testIterativeRandomSync(t *testing.T, count int) {
+func testIterativeRandomSync(t *testing.T, count int, scheme string) {
 	// Create a random trie to copy
-	srcDb, srcTrie, srcData := makeTestTrie()
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
@@ -273,7 +299,8 @@ func testIterativeRandomSync(t *testing.T, count int) {
 		// Fetch all the queued nodes in a random order
 		results := make([]NodeSyncResult, 0, len(queue))
 		for path, element := range queue {
-			data, err := srcDb.Node(element.hash)
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 			if err != nil {
 				t.Fatalf("failed to retrieve node data for %x: %v", element.hash, err)
 			}
@@ -302,18 +329,22 @@ func testIterativeRandomSync(t *testing.T, count int) {
 		}
 	}
 	// Cross check that the two tries are in sync
-	checkTrieContents(t, triedb, srcTrie.Hash().Bytes(), srcData)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
 }
 
 // Tests that the trie scheduler can correctly reconstruct the state even if only
 // partial results are returned (Even those randomly), others sent only later.
 func TestIterativeRandomDelayedSync(t *testing.T) {
+	testIterativeRandomDelayedSync(t, rawdb.HashScheme)
+	// testIterativeRandomDelayedSync(t, rawdb.PathScheme)
+}
+
+func testIterativeRandomDelayedSync(t *testing.T, scheme string) {
 	// Create a random trie to copy
-	srcDb, srcTrie, srcData := makeTestTrie()
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
@@ -331,7 +362,8 @@ func TestIterativeRandomDelayedSync(t *testing.T) {
 		// Sync only half of the scheduled nodes, even those in random order
 		results := make([]NodeSyncResult, 0, len(queue)/2+1)
 		for path, element := range queue {
-			data, err := srcDb.Node(element.hash)
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 			if err != nil {
 				t.Fatalf("failed to retrieve node data for %x: %v", element.hash, err)
 			}
@@ -365,18 +397,22 @@ func TestIterativeRandomDelayedSync(t *testing.T) {
 		}
 	}
 	// Cross check that the two tries are in sync
-	checkTrieContents(t, triedb, srcTrie.Hash().Bytes(), srcData)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
 }
 
 // Tests that a trie sync will not request nodes multiple times, even if they
 // have such references.
 func TestDuplicateAvoidanceSync(t *testing.T) {
+	testDuplicateAvoidanceSync(t, rawdb.HashScheme)
+	// testDuplicateAvoidanceSync(t, rawdb.PathScheme)
+}
+
+func testDuplicateAvoidanceSync(t *testing.T, scheme string) {
 	// Create a random trie to copy
-	srcDb, srcTrie, srcData := makeTestTrie()
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
@@ -395,7 +431,8 @@ func TestDuplicateAvoidanceSync(t *testing.T) {
 	for len(elements) > 0 {
 		results := make([]NodeSyncResult, len(elements))
 		for i, element := range elements {
-			data, err := srcDb.Node(element.hash)
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 			if err != nil {
 				t.Fatalf("failed to retrieve node data for %x: %v", element.hash, err)
 			}
@@ -428,25 +465,31 @@ func TestDuplicateAvoidanceSync(t *testing.T) {
 		}
 	}
 	// Cross check that the two tries are in sync
-	checkTrieContents(t, triedb, srcTrie.Hash().Bytes(), srcData)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
 }
 
 // Tests that at any point in time during a sync, only complete sub-tries are in
 // the database.
-func TestIncompleteSync(t *testing.T) {
+func TestIncompleteSyncHash(t *testing.T) {
+	testIncompleteSync(t, rawdb.HashScheme)
+	// testIncompleteSync(t, rawdb.PathScheme)
+}
+
+func testIncompleteSync(t *testing.T, scheme string) {
 	t.Parallel()
+
 	// Create a random trie to copy
-	srcDb, srcTrie, _ := makeTestTrie()
+	_, srcDb, srcTrie, _ := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
 	// at the testing trie.
 	var (
-		added    []common.Hash
+		addedKeys   []string
+		addedHashes []common.Hash
 		elements    []trieElement
 		root        = srcTrie.Hash()
 	)
@@ -462,7 +505,8 @@ func TestIncompleteSync(t *testing.T) {
 		// Fetch a batch of trie nodes
 		results := make([]NodeSyncResult, len(elements))
 		for i, element := range elements {
-			data, err := srcDb.Node(element.hash)
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 			if err != nil {
 				t.Fatalf("failed to retrieve node data for %x: %v", element.hash, err)
 			}
@@ -483,11 +527,8 @@ func TestIncompleteSync(t *testing.T) {
 		for _, result := range results {
 			hash := crypto.Keccak256Hash(result.Data)
 			if hash != root {
-				added = append(added, hash)
-			}
-			// Check that all known sub-tries in the synced trie are complete
-			if err := checkTrieConsistency(triedb, hash); err != nil {
-				t.Fatalf("trie inconsistent: %v", err)
+				addedKeys = append(addedKeys, result.Path)
+				addedHashes = append(addedHashes, crypto.Keccak256Hash(result.Data))
 			}
 		}
 		// Fetch the next batch to retrieve
@@ -502,25 +543,31 @@ func TestIncompleteSync(t *testing.T) {
 		}
 	}
 	// Sanity check that removing any node from the database is detected
-	for _, hash := range added {
-		value, _ := diskdb.Get(hash.Bytes())
-		diskdb.Delete(hash.Bytes())
-		if err := checkTrieConsistency(triedb, root); err == nil {
-			t.Fatalf("trie inconsistency not caught, missing: %x", hash)
+	for i, path := range addedKeys {
+		owner, inner := ResolvePath([]byte(path))
+		nodeHash := addedHashes[i]
+		value := rawdb.ReadTrieNode(diskdb, owner, inner, nodeHash, scheme)
+		rawdb.DeleteTrieNode(diskdb, owner, inner, nodeHash, scheme)
+		if err := checkTrieConsistency(diskdb, srcDb.Scheme(), root); err == nil {
+			t.Fatalf("trie inconsistency not caught, missing: %x", path)
 		}
-		diskdb.Put(hash.Bytes(), value)
+		rawdb.WriteTrieNode(diskdb, owner, inner, nodeHash, value, scheme)
 	}
 }
 
 // Tests that trie nodes get scheduled lexicographically when having the same
 // depth.
 func TestSyncOrdering(t *testing.T) {
+	testSyncOrdering(t, rawdb.HashScheme)
+	// testSyncOrdering(t, rawdb.PathScheme)
+}
+
+func testSyncOrdering(t *testing.T, scheme string) {
 	// Create a random trie to copy
-	srcDb, srcTrie, srcData := makeTestTrie()
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
 
 	// Create a destination trie and sync with the scheduler, tracking the requests
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
 	sched := NewSync(srcTrie.Hash(), diskdb, nil, srcDb.Scheme())
 
 	// The code requests are ignored here since there is no code
@@ -542,7 +589,8 @@ func TestSyncOrdering(t *testing.T) {
 	for len(elements) > 0 {
 		results := make([]NodeSyncResult, len(elements))
 		for i, element := range elements {
-			data, err := srcDb.Node(element.hash)
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(srcTrie.Hash()).Node(owner, inner, element.hash)
 			if err != nil {
 				t.Fatalf("failed to retrieve node data for %x: %v", element.hash, err)
 			}
@@ -571,7 +619,7 @@ func TestSyncOrdering(t *testing.T) {
 		}
 	}
 	// Cross check that the two tries are in sync
-	checkTrieContents(t, triedb, srcTrie.Hash().Bytes(), srcData)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
 
 	// Check that the trie nodes have been requested path-ordered
 	for i := 0; i < len(reqs)-1; i++ {
@@ -585,3 +633,116 @@ func TestSyncOrdering(t *testing.T) {
 		}
 	}
 }
+
+func syncWith(t *testing.T, root common.Hash, db ethdb.Database, srcDb *Database) {
+	// Create a destination trie and sync with the scheduler
+	sched := NewSync(root, db, nil, srcDb.Scheme())
+
+	// The code requests are ignored here since there is no code
+	// at the testing trie.
+	paths, nodes, _ := sched.Missing(1)
+	var elements []trieElement
+	for i := 0; i < len(paths); i++ {
+		elements = append(elements, trieElement{
+			path:     paths[i],
+			hash:     nodes[i],
+			syncPath: NewSyncPath([]byte(paths[i])),
+		})
+	}
+	for len(elements) > 0 {
+		results := make([]NodeSyncResult, len(elements))
+		for i, element := range elements {
+			owner, inner := ResolvePath([]byte(element.path))
+			data, err := srcDb.Reader(root).Node(owner, inner, element.hash)
+			if err != nil {
+				t.Fatalf("failed to retrieve node data for hash %x: %v", element.hash, err)
+			}
+			results[i] = NodeSyncResult{element.path, data}
+		}
+		for index, result := range results {
+			if err := sched.ProcessNode(result); err != nil {
+				t.Fatalf("failed to process result[%d][%v] data %v %v", index, []byte(result.Path), result.Data, err)
+			}
+		}
+		batch := db.NewBatch()
+		if err := sched.Commit(batch); err != nil {
+			t.Fatalf("failed to commit data: %v", err)
+		}
+		batch.Write()
+
+		paths, nodes, _ = sched.Missing(1)
+		elements = elements[:0]
+		for i := 0; i < len(paths); i++ {
+			elements = append(elements, trieElement{
+				path:     paths[i],
+				hash:     nodes[i],
+				syncPath: NewSyncPath([]byte(paths[i])),
+			})
+		}
+	}
+}
+
+// Tests that the syncing target is keeping moving which may overwrite the stale
+// states synced in the last cycle.
+func TestSyncMovingTarget(t *testing.T) {
+	testSyncMovingTarget(t, rawdb.HashScheme)
+	// testSyncMovingTarget(t, rawdb.PathScheme)
+}
+
+func testSyncMovingTarget(t *testing.T, scheme string) {
+	// Create a random trie to copy
+	_, srcDb, srcTrie, srcData := makeTestTrie(scheme)
+
+	// Create a destination trie and sync with the scheduler
+	diskdb := rawdb.NewMemoryDatabase()
+	syncWith(t, srcTrie.Hash(), diskdb, srcDb)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), srcData)
+
+	// Push more modifications into the src trie, to see if dest trie can still
+	// sync with it(overwrite stale states)
+	var (
+		preRoot = srcTrie.Hash()
+		diff    = make(map[string][]byte)
+	)
+	for i := byte(0); i < 10; i++ {
+		key, val := randBytes(32), randBytes(32)
+		srcTrie.MustUpdate(key, val)
+		diff[string(key)] = val
+	}
+	root, nodes := srcTrie.Commit(false)
+	if err := srcDb.Update(root, preRoot, trienode.NewWithNodeSet(nodes)); err != nil {
+		panic(err)
+	}
+	if err := srcDb.Commit(root, false); err != nil {
+		panic(err)
+	}
+	preRoot = root
+	srcTrie, _ = NewStateTrie(TrieID(root), srcDb)
+
+	syncWith(t, srcTrie.Hash(), diskdb, srcDb)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), diff)
+
+	// Revert added modifications from the src trie, to see if dest trie can still
+	// sync with it(overwrite reverted states)
+	var reverted = make(map[string][]byte)
+	for k := range diff {
+		srcTrie.MustDelete([]byte(k))
+		reverted[k] = nil
+	}
+	for k := range srcData {
+		val := randBytes(32)
+		srcTrie.MustUpdate([]byte(k), val)
+		reverted[k] = val
+	}
+	root, nodes = srcTrie.Commit(false)
+	if err := srcDb.Update(root, preRoot, trienode.NewWithNodeSet(nodes)); err != nil {
+		panic(err)
+	}
+	if err := srcDb.Commit(root, false); err != nil {
+		panic(err)
+	}
+	srcTrie, _ = NewStateTrie(TrieID(root), srcDb)
+
+	syncWith(t, srcTrie.Hash(), diskdb, srcDb)
+	checkTrieContents(t, diskdb, srcDb.Scheme(), srcTrie.Hash().Bytes(), reverted)
+}

trie/tracer.go

@@ -115,7 +115,7 @@ func (t *tracer) copy() *tracer {
 }
 
 // markDeletions puts all tracked deletions into the provided nodeset.
-func (t *tracer) markDeletions(set *NodeSet) {
+func (t *tracer) markDeletions(set *trienode.NodeSet) {
 	for path := range t.deletes {
 		// It's possible a few deleted nodes were embedded
 		// in their parent before, the deletions can be no
@@ -124,6 +124,6 @@ func (t *tracer) markDeletions(set *NodeSet) {
 		if !ok {
 			continue
 		}
-		set.addNode([]byte(path), trienode.NewWithPrev(common.Hash{}, nil, prev))
+		set.AddNode([]byte(path), trienode.NewWithPrev(common.Hash{}, nil, prev))
 	}
 }

trie/tracer_test.go

@@ -22,6 +22,8 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 var (
@@ -69,7 +71,7 @@ func testTrieTracer(t *testing.T, vals []struct{ k, v string }) {
 	insertSet := copySet(trie.tracer.inserts) // copy before commit
 	deleteSet := copySet(trie.tracer.deletes) // copy before commit
 	root, nodes := trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	seen := setKeys(iterNodes(db, root))
 	if !compareSet(insertSet, seen) {
@@ -135,7 +137,7 @@ func testAccessList(t *testing.T, vals []struct{ k, v string }) {
 		trie.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	root, nodes := trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	trie, _ = New(TrieID(root), db)
 	if err := verifyAccessList(orig, trie, nodes); err != nil {
@@ -143,13 +145,14 @@ func testAccessList(t *testing.T, vals []struct{ k, v string }) {
 	}
 
 	// Update trie
+	parent := root
 	trie, _ = New(TrieID(root), db)
 	orig = trie.Copy()
 	for _, val := range vals {
 		trie.MustUpdate([]byte(val.k), randBytes(32))
 	}
 	root, nodes = trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, parent, trienode.NewWithNodeSet(nodes))
 
 	trie, _ = New(TrieID(root), db)
 	if err := verifyAccessList(orig, trie, nodes); err != nil {
@@ -157,6 +160,7 @@ func testAccessList(t *testing.T, vals []struct{ k, v string }) {
 	}
 
 	// Add more new nodes
+	parent = root
 	trie, _ = New(TrieID(root), db)
 	orig = trie.Copy()
 	var keys []string
@@ -166,7 +170,7 @@ func testAccessList(t *testing.T, vals []struct{ k, v string }) {
 		trie.MustUpdate(key, randBytes(32))
 	}
 	root, nodes = trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, parent, trienode.NewWithNodeSet(nodes))
 
 	trie, _ = New(TrieID(root), db)
 	if err := verifyAccessList(orig, trie, nodes); err != nil {
@@ -174,13 +178,14 @@ func testAccessList(t *testing.T, vals []struct{ k, v string }) {
 	}
 
 	// Partial deletions
+	parent = root
 	trie, _ = New(TrieID(root), db)
 	orig = trie.Copy()
 	for _, key := range keys {
 		trie.MustUpdate([]byte(key), nil)
 	}
 	root, nodes = trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, parent, trienode.NewWithNodeSet(nodes))
 
 	trie, _ = New(TrieID(root), db)
 	if err := verifyAccessList(orig, trie, nodes); err != nil {
@@ -188,13 +193,14 @@ func testAccessList(t *testing.T, vals []struct{ k, v string }) {
 	}
 
 	// Delete all
+	parent = root
 	trie, _ = New(TrieID(root), db)
 	orig = trie.Copy()
 	for _, val := range vals {
 		trie.MustUpdate([]byte(val.k), nil)
 	}
 	root, nodes = trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, parent, trienode.NewWithNodeSet(nodes))
 
 	trie, _ = New(TrieID(root), db)
 	if err := verifyAccessList(orig, trie, nodes); err != nil {
@@ -213,7 +219,7 @@ func TestAccessListLeak(t *testing.T) {
 		trie.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	root, nodes := trie.Commit(false)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	var cases = []struct {
 		op func(tr *Trie)
@@ -263,15 +269,16 @@ func TestTinyTree(t *testing.T) {
 		trie.MustUpdate([]byte(val.k), randBytes(32))
 	}
 	root, set := trie.Commit(false)
-	db.Update(NewWithNodeSet(set))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(set))
 
+	parent := root
 	trie, _ = New(TrieID(root), db)
 	orig := trie.Copy()
 	for _, val := range tiny {
 		trie.MustUpdate([]byte(val.k), []byte(val.v))
 	}
 	root, set = trie.Commit(false)
-	db.Update(NewWithNodeSet(set))
+	db.Update(root, parent, trienode.NewWithNodeSet(set))
 
 	trie, _ = New(TrieID(root), db)
 	if err := verifyAccessList(orig, trie, set); err != nil {

trie/trie.go

@@ -25,6 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 )
 
 // Trie is a Merkle Patricia Trie. Use New to create a trie that sits on
@@ -95,7 +96,7 @@ func New(id *ID, db NodeReader) (*Trie, error) {
 
 // NewEmpty is a shortcut to create empty tree. It's mostly used in tests.
 func NewEmpty(db *Database) *Trie {
-	tr, _ := New(TrieID(common.Hash{}), db)
+	tr, _ := New(TrieID(types.EmptyRootHash), db)
 	return tr
 }
 
@@ -571,10 +572,10 @@ func (t *Trie) Hash() common.Hash {
 // The returned nodeset can be nil if the trie is clean (nothing to commit).
 // Once the trie is committed, it's not usable anymore. A new trie must
 // be created with new root and updated trie database for following usage
-func (t *Trie) Commit(collectLeaf bool) (common.Hash, *NodeSet) {
+func (t *Trie) Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet) {
 	defer t.tracer.reset()
 
-	nodes := NewNodeSet(t.owner)
+	nodes := trienode.NewNodeSet(t.owner)
 	t.tracer.markDeletions(nodes)
 
 	// Trie is empty and can be classified into two types of situations:

trie/trie_reader.go

@@ -32,9 +32,9 @@ type Reader interface {
 
 // NodeReader wraps all the necessary functions for accessing trie node.
 type NodeReader interface {
-	// GetReader returns a reader for accessing all trie nodes with provided
+	// Reader returns a reader for accessing all trie nodes with provided
 	// state root. Nil is returned in case the state is not available.
-	GetReader(root common.Hash) Reader
+	Reader(root common.Hash) Reader
 }
 
 // trieReader is a wrapper of the underlying node reader. It's not safe
@@ -47,7 +47,7 @@ type trieReader struct {
 
 // newTrieReader initializes the trie reader with the given node reader.
 func newTrieReader(stateRoot, owner common.Hash, db NodeReader) (*trieReader, error) {
-	reader := db.GetReader(stateRoot)
+	reader := db.Reader(stateRoot)
 	if reader == nil {
 		return nil, fmt.Errorf("state not found #%x", stateRoot)
 	}

trie/trie_test.go

@@ -35,6 +35,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie/trienode"
 	"golang.org/x/crypto/sha3"
 )
 
@@ -73,18 +74,23 @@ func TestMissingRoot(t *testing.T) {
 	}
 }
 
-func TestMissingNodeDisk(t *testing.T)    { testMissingNode(t, false) }
-func TestMissingNodeMemonly(t *testing.T) { testMissingNode(t, true) }
+func TestMissingNode(t *testing.T) {
+	testMissingNode(t, false, rawdb.HashScheme)
+	//testMissingNode(t, false, rawdb.PathScheme)
+	testMissingNode(t, true, rawdb.HashScheme)
+	//testMissingNode(t, true, rawdb.PathScheme)
+}
 
-func testMissingNode(t *testing.T, memonly bool) {
+func testMissingNode(t *testing.T, memonly bool, scheme string) {
 	diskdb := rawdb.NewMemoryDatabase()
-	triedb := NewDatabase(diskdb)
+	triedb := newTestDatabase(diskdb, scheme)
 
 	trie := NewEmpty(triedb)
 	updateString(trie, "120000", "qwerqwerqwerqwerqwerqwerqwerqwer")
 	updateString(trie, "123456", "asdfasdfasdfasdfasdfasdfasdfasdf")
 	root, nodes := trie.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
+	triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
+
 	if !memonly {
 		triedb.Commit(root, false)
 	}
@@ -115,34 +121,39 @@ func testMissingNode(t *testing.T, memonly bool) {
 		t.Errorf("Unexpected error: %v", err)
 	}
 
-	hash := common.HexToHash("0xe1d943cc8f061a0c0b98162830b970395ac9315654824bf21b73b891365262f9")
+	var (
+		path []byte
+		hash = common.HexToHash("0xe1d943cc8f061a0c0b98162830b970395ac9315654824bf21b73b891365262f9")
+	)
+	for p, n := range nodes.Nodes {
+		if n.Hash == hash {
+			path = common.CopyBytes([]byte(p))
+			break
+		}
+	}
+	trie, _ = New(TrieID(root), triedb)
 	if memonly {
-		delete(triedb.dirties, hash)
+		trie.reader.banned = map[string]struct{}{string(path): {}}
 	} else {
-		diskdb.Delete(hash[:])
+		rawdb.DeleteTrieNode(diskdb, common.Hash{}, path, hash, scheme)
 	}
 
-	trie, _ = New(TrieID(root), triedb)
 	_, err = trie.Get([]byte("120000"))
 	if _, ok := err.(*MissingNodeError); !ok {
 		t.Errorf("Wrong error: %v", err)
 	}
-	trie, _ = New(TrieID(root), triedb)
 	_, err = trie.Get([]byte("120099"))
 	if _, ok := err.(*MissingNodeError); !ok {
 		t.Errorf("Wrong error: %v", err)
 	}
-	trie, _ = New(TrieID(root), triedb)
 	_, err = trie.Get([]byte("123456"))
 	if err != nil {
 		t.Errorf("Unexpected error: %v", err)
 	}
-	trie, _ = New(TrieID(root), triedb)
 	err = trie.Update([]byte("120099"), []byte("zxcv"))
 	if _, ok := err.(*MissingNodeError); !ok {
 		t.Errorf("Wrong error: %v", err)
 	}
-	trie, _ = New(TrieID(root), triedb)
 	err = trie.Delete([]byte("123456"))
 	if _, ok := err.(*MissingNodeError); !ok {
 		t.Errorf("Wrong error: %v", err)
@@ -192,7 +203,7 @@ func TestGet(t *testing.T) {
 			return
 		}
 		root, nodes := trie.Commit(false)
-		db.Update(NewWithNodeSet(nodes))
+		db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 		trie, _ = New(TrieID(root), db)
 	}
 }
@@ -249,8 +260,8 @@ func TestEmptyValues(t *testing.T) {
 }
 
 func TestReplication(t *testing.T) {
-	triedb := NewDatabase(rawdb.NewMemoryDatabase())
-	trie := NewEmpty(triedb)
+	db := NewDatabase(rawdb.NewMemoryDatabase())
+	trie := NewEmpty(db)
 	vals := []struct{ k, v string }{
 		{"do", "verb"},
 		{"ether", "wookiedoo"},
@@ -263,13 +274,13 @@ func TestReplication(t *testing.T) {
 	for _, val := range vals {
 		updateString(trie, val.k, val.v)
 	}
-	exp, nodes := trie.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
+	root, nodes := trie.Commit(false)
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 
 	// create a new trie on top of the database and check that lookups work.
-	trie2, err := New(TrieID(exp), triedb)
+	trie2, err := New(TrieID(root), db)
 	if err != nil {
-		t.Fatalf("can't recreate trie at %x: %v", exp, err)
+		t.Fatalf("can't recreate trie at %x: %v", root, err)
 	}
 	for _, kv := range vals {
 		if string(getString(trie2, kv.k)) != kv.v {
@@ -277,17 +288,17 @@ func TestReplication(t *testing.T) {
 		}
 	}
 	hash, nodes := trie2.Commit(false)
-	if hash != exp {
-		t.Errorf("root failure. expected %x got %x", exp, hash)
+	if hash != root {
+		t.Errorf("root failure. expected %x got %x", root, hash)
 	}
 
 	// recreate the trie after commit
 	if nodes != nil {
-		triedb.Update(NewWithNodeSet(nodes))
+		db.Update(hash, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	}
-	trie2, err = New(TrieID(hash), triedb)
+	trie2, err = New(TrieID(hash), db)
 	if err != nil {
-		t.Fatalf("can't recreate trie at %x: %v", exp, err)
+		t.Fatalf("can't recreate trie at %x: %v", hash, err)
 	}
 	// perform some insertions on the new trie.
 	vals2 := []struct{ k, v string }{
@@ -304,8 +315,8 @@ func TestReplication(t *testing.T) {
 	for _, val := range vals2 {
 		updateString(trie2, val.k, val.v)
 	}
-	if hash := trie2.Hash(); hash != exp {
-		t.Errorf("root failure. expected %x got %x", exp, hash)
+	if trie2.Hash() != hash {
+		t.Errorf("root failure. expected %x got %x", hash, hash)
 	}
 }
 
@@ -402,12 +413,12 @@ func (randTest) Generate(r *rand.Rand, size int) reflect.Value {
 	return reflect.ValueOf(steps)
 }
 
-func verifyAccessList(old *Trie, new *Trie, set *NodeSet) error {
+func verifyAccessList(old *Trie, new *Trie, set *trienode.NodeSet) error {
 	deletes, inserts, updates := diffTries(old, new)
 
 	// Check insertion set
 	for path := range inserts {
-		n, ok := set.nodes[path]
+		n, ok := set.Nodes[path]
 		if !ok || n.IsDeleted() {
 			return errors.New("expect new node")
 		}
@@ -417,7 +428,7 @@ func verifyAccessList(old *Trie, new *Trie, set *NodeSet) error {
 	}
 	// Check deletion set
 	for path, blob := range deletes {
-		n, ok := set.nodes[path]
+		n, ok := set.Nodes[path]
 		if !ok || !n.IsDeleted() {
 			return errors.New("expect deleted node")
 		}
@@ -430,7 +441,7 @@ func verifyAccessList(old *Trie, new *Trie, set *NodeSet) error {
 	}
 	// Check update set
 	for path, blob := range updates {
-		n, ok := set.nodes[path]
+		n, ok := set.Nodes[path]
 		if !ok || n.IsDeleted() {
 			return errors.New("expect updated node")
 		}
@@ -445,8 +456,13 @@ func verifyAccessList(old *Trie, new *Trie, set *NodeSet) error {
 }
 
 func runRandTest(rt randTest) bool {
+	var scheme = rawdb.HashScheme
+	//if rand.Intn(2) == 0 {
+	//	scheme = rawdb.PathScheme
+	//}
 	var (
-		triedb   = NewDatabase(rawdb.NewMemoryDatabase())
+		origin   = types.EmptyRootHash
+		triedb   = newTestDatabase(rawdb.NewMemoryDatabase(), scheme)
 		tr       = NewEmpty(triedb)
 		values   = make(map[string]string) // tracks content of the trie
 		origTrie = NewEmpty(triedb)
@@ -487,7 +503,7 @@ func runRandTest(rt randTest) bool {
 		case opCommit:
 			root, nodes := tr.Commit(true)
 			if nodes != nil {
-				triedb.Update(NewWithNodeSet(nodes))
+				triedb.Update(root, origin, trienode.NewWithNodeSet(nodes))
 			}
 			newtr, err := New(TrieID(root), triedb)
 			if err != nil {
@@ -502,6 +518,7 @@ func runRandTest(rt randTest) bool {
 			}
 			tr = newtr
 			origTrie = tr.Copy()
+			origin = root
 		case opItercheckhash:
 			checktr := NewEmpty(triedb)
 			it := NewIterator(tr.NodeIterator(nil))
@@ -821,7 +838,7 @@ func TestCommitSequence(t *testing.T) {
 		}
 		// Flush trie -> database
 		root, nodes := trie.Commit(false)
-		db.Update(NewWithNodeSet(nodes))
+		db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 		// Flush memdb -> disk (sponge)
 		db.Commit(root, false)
 		if got, exp := s.sponge.Sum(nil), tc.expWriteSeqHash; !bytes.Equal(got, exp) {
@@ -862,7 +879,7 @@ func TestCommitSequenceRandomBlobs(t *testing.T) {
 		}
 		// Flush trie -> database
 		root, nodes := trie.Commit(false)
-		db.Update(NewWithNodeSet(nodes))
+		db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 		// Flush memdb -> disk (sponge)
 		db.Commit(root, false)
 		if got, exp := s.sponge.Sum(nil), tc.expWriteSeqHash; !bytes.Equal(got, exp) {
@@ -902,7 +919,7 @@ func TestCommitSequenceStackTrie(t *testing.T) {
 		// Flush trie -> database
 		root, nodes := trie.Commit(false)
 		// Flush memdb -> disk (sponge)
-		db.Update(NewWithNodeSet(nodes))
+		db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 		db.Commit(root, false)
 		// And flush stacktrie -> disk
 		stRoot, err := stTrie.Commit()
@@ -950,7 +967,7 @@ func TestCommitSequenceSmallRoot(t *testing.T) {
 	// Flush trie -> database
 	root, nodes := trie.Commit(false)
 	// Flush memdb -> disk (sponge)
-	db.Update(NewWithNodeSet(nodes))
+	db.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	db.Commit(root, false)
 	// And flush stacktrie -> disk
 	stRoot, err := stTrie.Commit()
@@ -1121,8 +1138,8 @@ func benchmarkDerefRootFixedSize(b *testing.B, addresses [][20]byte, accounts []
 		trie.MustUpdate(crypto.Keccak256(addresses[i][:]), accounts[i])
 	}
 	h := trie.Hash()
-	_, nodes := trie.Commit(false)
-	triedb.Update(NewWithNodeSet(nodes))
+	root, nodes := trie.Commit(false)
+	triedb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
 	b.StartTimer()
 	triedb.Dereference(h)
 	b.StopTimer()

trie/triedb/hashdb/database.go

@@ -14,12 +14,11 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-package trie
+package hashdb
 
 import (
 	"errors"
 	"reflect"
-	"runtime"
 	"sync"
 	"time"
 
@@ -58,10 +57,10 @@ var (
 	memcacheCommitSizeMeter  = metrics.NewRegisteredMeter("trie/memcache/commit/size", nil)
 )
 
-// childResolver defines the required method to decode the provided
+// ChildResolver defines the required method to decode the provided
 // trie node and iterate the children on top.
-type childResolver interface {
-	forEach(node []byte, onChild func(common.Hash))
+type ChildResolver interface {
+	ForEach(node []byte, onChild func(common.Hash))
 }
 
 // Database is an intermediate write layer between the trie data structures and
@@ -74,7 +73,7 @@ type childResolver interface {
 // servers even while the trie is executing expensive garbage collection.
 type Database struct {
 	diskdb   ethdb.Database // Persistent storage for matured trie nodes
-	resolver childResolver  // The handler to resolve children of nodes
+	resolver ChildResolver  // The handler to resolve children of nodes
 
 	cleans  *fastcache.Cache            // GC friendly memory cache of clean node RLPs
 	dirties map[common.Hash]*cachedNode // Data and references relationships of dirty trie nodes
@@ -91,7 +90,6 @@ type Database struct {
 
 	dirtiesSize  common.StorageSize // Storage size of the dirty node cache (exc. metadata)
 	childrenSize common.StorageSize // Storage size of the external children tracking
-	preimages    *preimageStore     // The store for caching preimages
 
 	lock sync.RWMutex
 }
@@ -114,49 +112,20 @@ var cachedNodeSize = int(reflect.TypeOf(cachedNode{}).Size())
 // forChildren invokes the callback for all the tracked children of this node,
 // both the implicit ones from inside the node as well as the explicit ones
 // from outside the node.
-func (n *cachedNode) forChildren(resolver childResolver, onChild func(hash common.Hash)) {
+func (n *cachedNode) forChildren(resolver ChildResolver, onChild func(hash common.Hash)) {
 	for child := range n.external {
 		onChild(child)
 	}
-	resolver.forEach(n.node, onChild)
+	resolver.ForEach(n.node, onChild)
 }
 
-// Config defines all necessary options for database.
-type Config struct {
-	Cache     int    // Memory allowance (MB) to use for caching trie nodes in memory
-	Journal   string // Journal of clean cache to survive node restarts
-	Preimages bool   // Flag whether the preimage of trie key is recorded
-}
-
-// NewDatabase creates a new trie database to store ephemeral trie content before
-// its written out to disk or garbage collected. No read cache is created, so all
-// data retrievals will hit the underlying disk database.
-func NewDatabase(diskdb ethdb.Database) *Database {
-	return NewDatabaseWithConfig(diskdb, nil)
-}
-
-// NewDatabaseWithConfig creates a new trie database to store ephemeral trie content
-// before its written out to disk or garbage collected. It also acts as a read cache
-// for nodes loaded from disk.
-func NewDatabaseWithConfig(diskdb ethdb.Database, config *Config) *Database {
-	var cleans *fastcache.Cache
-	if config != nil && config.Cache > 0 {
-		if config.Journal == "" {
-			cleans = fastcache.New(config.Cache * 1024 * 1024)
-		} else {
-			cleans = fastcache.LoadFromFileOrNew(config.Journal, config.Cache*1024*1024)
-		}
-	}
-	var preimage *preimageStore
-	if config != nil && config.Preimages {
-		preimage = newPreimageStore(diskdb)
-	}
+// New initializes the hash-based node database.
+func New(diskdb ethdb.Database, cleans *fastcache.Cache, resolver ChildResolver) *Database {
 	return &Database{
 		diskdb:   diskdb,
-		resolver:  mptResolver{},
+		resolver: resolver,
 		cleans:   cleans,
 		dirties:  make(map[common.Hash]*cachedNode),
-		preimages: preimage,
 	}
 }
 
@@ -369,13 +338,6 @@ func (db *Database) Cap(limit common.StorageSize) error {
 	size := db.dirtiesSize + common.StorageSize(len(db.dirties)*cachedNodeSize)
 	size += db.childrenSize
 
-	// If the preimage cache got large enough, push to disk. If it's still small
-	// leave for later to deduplicate writes.
-	if db.preimages != nil {
-		if err := db.preimages.commit(false); err != nil {
-			return err
-		}
-	}
 	// Keep committing nodes from the flush-list until we're below allowance
 	oldest := db.oldest
 	for size > limit && oldest != (common.Hash{}) {
@@ -450,12 +412,6 @@ func (db *Database) Commit(node common.Hash, report bool) error {
 	start := time.Now()
 	batch := db.diskdb.NewBatch()
 
-	// Move all of the accumulated preimages into a write batch
-	if db.preimages != nil {
-		if err := db.preimages.commit(true); err != nil {
-			return err
-		}
-	}
 	// Move the trie itself into the batch, flushing if enough data is accumulated
 	nodes, storage := len(db.dirties), db.dirtiesSize
 
@@ -584,9 +540,21 @@ func (c *cleaner) Delete(key []byte) error {
 	panic("not implemented")
 }
 
-// Update inserts the dirty nodes in provided nodeset into database and
-// link the account trie with multiple storage tries if necessary.
-func (db *Database) Update(nodes *MergedNodeSet) error {
+// Initialized returns an indicator if state data is already initialized
+// in hash-based scheme by checking the presence of genesis state.
+func (db *Database) Initialized(genesisRoot common.Hash) bool {
+	return rawdb.HasLegacyTrieNode(db.diskdb, genesisRoot)
+}
+
+// Update inserts the dirty nodes in provided nodeset into database and link the
+// account trie with multiple storage tries if necessary.
+func (db *Database) Update(root common.Hash, parent common.Hash, nodes *trienode.MergedNodeSet) error {
+	// Ensure the parent state is present and signal a warning if not.
+	if parent != types.EmptyRootHash {
+		if blob, _ := db.Node(parent); len(blob) == 0 {
+			log.Error("parent state is not present")
+		}
+	}
 	db.lock.Lock()
 	defer db.lock.Unlock()
 
@@ -597,18 +565,18 @@ func (db *Database) Update(nodes *MergedNodeSet) error {
 	// Note, the storage tries must be flushed before the account trie to
 	// retain the invariant that children go into the dirty cache first.
 	var order []common.Hash
-	for owner := range nodes.sets {
+	for owner := range nodes.Sets {
 		if owner == (common.Hash{}) {
 			continue
 		}
 		order = append(order, owner)
 	}
-	if _, ok := nodes.sets[common.Hash{}]; ok {
+	if _, ok := nodes.Sets[common.Hash{}]; ok {
 		order = append(order, common.Hash{})
 	}
 	for _, owner := range order {
-		subset := nodes.sets[owner]
-		subset.forEachWithOrder(func(path string, n *trienode.Node) {
+		subset := nodes.Sets[owner]
+		subset.ForEachWithOrder(func(path string, n *trienode.Node) {
 			if n.IsDeleted() {
 				return // ignore deletion
 			}
@@ -617,14 +585,14 @@ func (db *Database) Update(nodes *MergedNodeSet) error {
 	}
 	// Link up the account trie and storage trie if the node points
 	// to an account trie leaf.
-	if set, present := nodes.sets[common.Hash{}]; present {
-		for _, n := range set.leaves {
+	if set, present := nodes.Sets[common.Hash{}]; present {
+		for _, n := range set.Leaves {
 			var account types.StateAccount
-			if err := rlp.DecodeBytes(n.blob, &account); err != nil {
+			if err := rlp.DecodeBytes(n.Blob, &account); err != nil {
 				return err
 			}
 			if account.Root != types.EmptyRootHash {
-				db.reference(account.Root, n.parent)
+				db.reference(account.Root, n.Parent)
 			}
 		}
 	}
@@ -633,7 +601,7 @@ func (db *Database) Update(nodes *MergedNodeSet) error {
 
 // Size returns the current storage size of the memory cache in front of the
 // persistent database layer.
-func (db *Database) Size() (common.StorageSize, common.StorageSize) {
+func (db *Database) Size() common.StorageSize {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
@@ -641,89 +609,30 @@ func (db *Database) Size() (common.StorageSize, common.StorageSize) {
 	// the total memory consumption, the maintenance metadata is also needed to be
 	// counted.
 	var metadataSize = common.StorageSize(len(db.dirties) * cachedNodeSize)
-	var preimageSize common.StorageSize
-	if db.preimages != nil {
-		preimageSize = db.preimages.size()
-	}
-	return db.dirtiesSize + db.childrenSize + metadataSize, preimageSize
+	return db.dirtiesSize + db.childrenSize + metadataSize
 }
 
-// GetReader retrieves a node reader belonging to the given state root.
-func (db *Database) GetReader(root common.Hash) Reader {
-	return newHashReader(db)
-}
-
-// hashReader is reader of hashDatabase which implements the Reader interface.
-type hashReader struct {
-	db *Database
-}
-
-// newHashReader initializes the hash reader.
-func newHashReader(db *Database) *hashReader {
-	return &hashReader{db: db}
-}
-
-// Node retrieves the RLP-encoded trie node blob with the given node hash.
-// No error will be returned if the node is not found.
-func (reader *hashReader) Node(_ common.Hash, _ []byte, hash common.Hash) ([]byte, error) {
-	blob, _ := reader.db.Node(hash)
-	return blob, nil
-}
-
-// saveCache saves clean state cache to given directory path
-// using specified CPU cores.
-func (db *Database) saveCache(dir string, threads int) error {
-	if db.cleans == nil {
-		return nil
-	}
-	log.Info("Writing clean trie cache to disk", "path", dir, "threads", threads)
-
-	start := time.Now()
-	err := db.cleans.SaveToFileConcurrent(dir, threads)
-	if err != nil {
-		log.Error("Failed to persist clean trie cache", "error", err)
-		return err
-	}
-	log.Info("Persisted the clean trie cache", "path", dir, "elapsed", common.PrettyDuration(time.Since(start)))
-	return nil
-}
-
-// SaveCache atomically saves fast cache data to the given dir using all
-// available CPU cores.
-func (db *Database) SaveCache(dir string) error {
-	return db.saveCache(dir, runtime.GOMAXPROCS(0))
-}
-
-// SaveCachePeriodically atomically saves fast cache data to the given dir with
-// the specified interval. All dump operation will only use a single CPU core.
-func (db *Database) SaveCachePeriodically(dir string, interval time.Duration, stopCh <-chan struct{}) {
-	ticker := time.NewTicker(interval)
-	defer ticker.Stop()
-
-	for {
-		select {
-		case <-ticker.C:
-			db.saveCache(dir, 1)
-		case <-stopCh:
-			return
-		}
-	}
-}
-
-// CommitPreimages flushes the dangling preimages to disk. It is meant to be
-// called when closing the blockchain object, so that preimages are persisted
-// to the database.
-func (db *Database) CommitPreimages() error {
-	db.lock.Lock()
-	defer db.lock.Unlock()
-
-	if db.preimages == nil {
-		return nil
-	}
-	return db.preimages.commit(true)
-}
+// Close closes the trie database and releases all held resources.
+func (db *Database) Close() error { return nil }
 
 // Scheme returns the node scheme used in the database.
 func (db *Database) Scheme() string {
 	return rawdb.HashScheme
 }
+
+// Reader retrieves a node reader belonging to the given state root.
+func (db *Database) Reader(root common.Hash) *reader {
+	return &reader{db: db}
+}
+
+// reader is a state reader of Database which implements the Reader interface.
+type reader struct {
+	db *Database
+}
+
+// Node retrieves the trie node with the given node hash.
+// No error will be returned if the node is not found.
+func (reader *reader) Node(owner common.Hash, path []byte, hash common.Hash) ([]byte, error) {
+	blob, _ := reader.db.Node(hash)
+	return blob, nil
+}

trie/trienode/node.go

@@ -16,7 +16,13 @@
 
 package trienode
 
-import "github.com/ethereum/go-ethereum/common"
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common"
+)
 
 // Node is a wrapper which contains the encoded blob of the trie node and its
 // unique hash identifier. It is general enough that can be used to represent
@@ -65,3 +71,127 @@ func NewWithPrev(hash common.Hash, blob []byte, prev []byte) *WithPrev {
 		Prev: prev,
 	}
 }
+
+// leaf represents a trie leaf node
+type leaf struct {
+	Blob   []byte      // raw blob of leaf
+	Parent common.Hash // the hash of parent node
+}
+
+// NodeSet contains a set of nodes collected during the commit operation.
+// Each node is keyed by path. It's not thread-safe to use.
+type NodeSet struct {
+	Owner   common.Hash
+	Leaves  []*leaf
+	Nodes   map[string]*WithPrev
+	updates int // the count of updated and inserted nodes
+	deletes int // the count of deleted nodes
+}
+
+// NewNodeSet initializes a node set. The owner is zero for the account trie and
+// the owning account address hash for storage tries.
+func NewNodeSet(owner common.Hash) *NodeSet {
+	return &NodeSet{
+		Owner: owner,
+		Nodes: make(map[string]*WithPrev),
+	}
+}
+
+// ForEachWithOrder iterates the nodes with the order from bottom to top,
+// right to left, nodes with the longest path will be iterated first.
+func (set *NodeSet) ForEachWithOrder(callback func(path string, n *Node)) {
+	var paths sort.StringSlice
+	for path := range set.Nodes {
+		paths = append(paths, path)
+	}
+	// Bottom-up, longest path first
+	sort.Sort(sort.Reverse(paths))
+	for _, path := range paths {
+		callback(path, set.Nodes[path].Unwrap())
+	}
+}
+
+// AddNode adds the provided node into set.
+func (set *NodeSet) AddNode(path []byte, n *WithPrev) {
+	if n.IsDeleted() {
+		set.deletes += 1
+	} else {
+		set.updates += 1
+	}
+	set.Nodes[string(path)] = n
+}
+
+// AddLeaf adds the provided leaf node into set. TODO(rjl493456442) how can
+// we get rid of it?
+func (set *NodeSet) AddLeaf(parent common.Hash, blob []byte) {
+	set.Leaves = append(set.Leaves, &leaf{Blob: blob, Parent: parent})
+}
+
+// Size returns the number of dirty nodes in set.
+func (set *NodeSet) Size() (int, int) {
+	return set.updates, set.deletes
+}
+
+// Hashes returns the hashes of all updated nodes. TODO(rjl493456442) how can
+// we get rid of it?
+func (set *NodeSet) Hashes() []common.Hash {
+	var ret []common.Hash
+	for _, node := range set.Nodes {
+		ret = append(ret, node.Hash)
+	}
+	return ret
+}
+
+// Summary returns a string-representation of the NodeSet.
+func (set *NodeSet) Summary() string {
+	var out = new(strings.Builder)
+	fmt.Fprintf(out, "nodeset owner: %v\n", set.Owner)
+	if set.Nodes != nil {
+		for path, n := range set.Nodes {
+			// Deletion
+			if n.IsDeleted() {
+				fmt.Fprintf(out, "  [-]: %x prev: %x\n", path, n.Prev)
+				continue
+			}
+			// Insertion
+			if len(n.Prev) == 0 {
+				fmt.Fprintf(out, "  [+]: %x -> %v\n", path, n.Hash)
+				continue
+			}
+			// Update
+			fmt.Fprintf(out, "  [*]: %x -> %v prev: %x\n", path, n.Hash, n.Prev)
+		}
+	}
+	for _, n := range set.Leaves {
+		fmt.Fprintf(out, "[leaf]: %v\n", n)
+	}
+	return out.String()
+}
+
+// MergedNodeSet represents a merged node set for a group of tries.
+type MergedNodeSet struct {
+	Sets map[common.Hash]*NodeSet
+}
+
+// NewMergedNodeSet initializes an empty merged set.
+func NewMergedNodeSet() *MergedNodeSet {
+	return &MergedNodeSet{Sets: make(map[common.Hash]*NodeSet)}
+}
+
+// NewWithNodeSet constructs a merged nodeset with the provided single set.
+func NewWithNodeSet(set *NodeSet) *MergedNodeSet {
+	merged := NewMergedNodeSet()
+	merged.Merge(set)
+	return merged
+}
+
+// Merge merges the provided dirty nodes of a trie into the set. The assumption
+// is held that no duplicated set belonging to the same trie will be merged twice.
+func (set *MergedNodeSet) Merge(other *NodeSet) error {
+	_, present := set.Sets[other.Owner]
+	if present {
+		return fmt.Errorf("duplicate trie for owner %#x", other.Owner)
+	}
+	set.Sets[other.Owner] = other
+	return nil
+}