cmd, tests: fix snapshot dump and export-preimages (#32650)

Address #32646

cmd/geth/snapshot.go

@@ -561,17 +561,11 @@ func dumpState(ctx *cli.Context) error {
 	triedb := utils.MakeTrieDatabase(ctx, stack, db, false, true, false)
 	defer triedb.Close()
 
-	snapConfig := snapshot.Config{
+	stateIt, err := utils.NewStateIterator(triedb, db, root)
-		CacheSize:  256,
-		Recovery:   false,
-		NoBuild:    true,
-		AsyncBuild: false,
-	}
-	snaptree, err := snapshot.New(snapConfig, db, triedb, root)
 	if err != nil {
 		return err
 	}
-	accIt, err := snaptree.AccountIterator(root, common.BytesToHash(conf.Start))
+	accIt, err := stateIt.AccountIterator(root, common.BytesToHash(conf.Start))
 	if err != nil {
 		return err
 	}
@@ -605,7 +599,7 @@ func dumpState(ctx *cli.Context) error {
 		if !conf.SkipStorage {
 			da.Storage = make(map[common.Hash]string)
 
-			stIt, err := snaptree.StorageIterator(root, accIt.Hash(), common.Hash{})
+			stIt, err := stateIt.StorageIterator(root, accIt.Hash(), common.Hash{})
 			if err != nil {
 				return err
 			}
@@ -658,17 +652,11 @@ func snapshotExportPreimages(ctx *cli.Context) error {
 		}
 		root = headBlock.Root()
 	}
-	snapConfig := snapshot.Config{
+	stateIt, err := utils.NewStateIterator(triedb, chaindb, root)
-		CacheSize:  256,
-		Recovery:   false,
-		NoBuild:    true,
-		AsyncBuild: false,
-	}
-	snaptree, err := snapshot.New(snapConfig, chaindb, triedb, root)
 	if err != nil {
 		return err
 	}
-	return utils.ExportSnapshotPreimages(chaindb, snaptree, ctx.Args().First(), root)
+	return utils.ExportSnapshotPreimages(chaindb, stateIt, ctx.Args().First(), root)
 }
 
 // checkAccount iterates the snap data layers, and looks up the given account

cmd/utils/cmd.go

@@ -48,6 +48,7 @@ import (
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/triedb"
 	"github.com/urfave/cli/v2"
 )
 
@@ -567,9 +568,64 @@ func ExportPreimages(db ethdb.Database, fn string) error {
 	return nil
 }
 
+// StateIterator is a temporary structure for traversing state in order. It serves
+// as an aggregator for both path scheme and hash scheme implementations and should
+// be removed once the hash scheme is fully deprecated.
+type StateIterator struct {
+	scheme    string
+	root      common.Hash
+	triedb    *triedb.Database
+	snapshots *snapshot.Tree
+}
+
+// NewStateIterator constructs the state iterator with the specific root.
+func NewStateIterator(triedb *triedb.Database, db ethdb.Database, root common.Hash) (*StateIterator, error) {
+	if triedb.Scheme() == rawdb.PathScheme {
+		return &StateIterator{
+			scheme: rawdb.PathScheme,
+			root:   root,
+			triedb: triedb,
+		}, nil
+	}
+	config := snapshot.Config{
+		CacheSize:  256,
+		Recovery:   false,
+		NoBuild:    true,
+		AsyncBuild: false,
+	}
+	snapshots, err := snapshot.New(config, db, triedb, root)
+	if err != nil {
+		return nil, err
+	}
+	return &StateIterator{
+		scheme:    rawdb.HashScheme,
+		root:      root,
+		triedb:    triedb,
+		snapshots: snapshots,
+	}, nil
+}
+
+// AccountIterator creates a new account iterator for the specified root hash and
+// seeks to a starting account hash.
+func (it *StateIterator) AccountIterator(root common.Hash, start common.Hash) (snapshot.AccountIterator, error) {
+	if it.scheme == rawdb.PathScheme {
+		return it.triedb.AccountIterator(root, start)
+	}
+	return it.snapshots.AccountIterator(root, start)
+}
+
+// StorageIterator creates a new storage iterator for the specified root hash and
+// account. The iterator will be moved to the specific start position.
+func (it *StateIterator) StorageIterator(root common.Hash, accountHash common.Hash, start common.Hash) (snapshot.StorageIterator, error) {
+	if it.scheme == rawdb.PathScheme {
+		return it.triedb.StorageIterator(root, accountHash, start)
+	}
+	return it.snapshots.StorageIterator(root, accountHash, start)
+}
+
 // ExportSnapshotPreimages exports the preimages corresponding to the enumeration of
 // the snapshot for a given root.
-func ExportSnapshotPreimages(chaindb ethdb.Database, snaptree *snapshot.Tree, fn string, root common.Hash) error {
+func ExportSnapshotPreimages(chaindb ethdb.Database, stateIt *StateIterator, fn string, root common.Hash) error {
 	log.Info("Exporting preimages", "file", fn)
 
 	fh, err := os.OpenFile(fn, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.ModePerm)
@@ -602,7 +658,7 @@ func ExportSnapshotPreimages(chaindb ethdb.Database, snaptree *snapshot.Tree, fn
 	)
 	go func() {
 		defer close(hashCh)
-		accIt, err := snaptree.AccountIterator(root, common.Hash{})
+		accIt, err := stateIt.AccountIterator(root, common.Hash{})
 		if err != nil {
 			log.Error("Failed to create account iterator", "error", err)
 			return
@@ -619,7 +675,7 @@ func ExportSnapshotPreimages(chaindb ethdb.Database, snaptree *snapshot.Tree, fn
 			hashCh <- hashAndPreimageSize{Hash: accIt.Hash(), Size: common.AddressLength}
 
 			if acc.Root != (common.Hash{}) && acc.Root != types.EmptyRootHash {
-				stIt, err := snaptree.StorageIterator(root, accIt.Hash(), common.Hash{})
+				stIt, err := stateIt.StorageIterator(root, accIt.Hash(), common.Hash{})
 				if err != nil {
 					log.Error("Failed to create storage iterator", "error", err)
 					return

tests/state_test.go

@@ -156,8 +156,8 @@ func execStateTest(t *testing.T, st *testMatcher, test *StateTest) {
 			withTrace(t, test.gasLimit(subtest), func(vmconfig vm.Config) error {
 				var result error
 				test.Run(subtest, vmconfig, true, rawdb.PathScheme, func(err error, state *StateTestState) {
-					if state.Snapshots != nil && state.StateDB != nil {
+					if state.TrieDB != nil && state.StateDB != nil {
-						if _, err := state.Snapshots.Journal(state.StateDB.IntermediateRoot(false)); err != nil {
+						if err := state.TrieDB.Journal(state.StateDB.IntermediateRoot(false)); err != nil {
 							result = err
 							return
 						}

tests/state_test_util.go

@@ -523,7 +523,7 @@ func MakePreState(db ethdb.Database, accounts types.GenesisAlloc, snapshotter bo
 
 	// If snapshot is requested, initialize the snapshotter and use it in state.
 	var snaps *snapshot.Tree
-	if snapshotter {
+	if snapshotter && scheme == rawdb.HashScheme {
 		snapconfig := snapshot.Config{
 			CacheSize:  1,
 			Recovery:   false,