Add WriteStateSnapshot (#15 )

Adds a method to perform full-state snapshots by diffing against an empty state trie. This replicates the functionality of `ipld-eth-state-snapshot`, so that code can use this as a library; see: cerc-io/ipld-eth-state-snapshot#1 Note that due to how incremental diffs are processed (updates are processed after the trie has been traversed) the iterator state doesn't fully capture the progress of the diff, so it's not currently feasible to state diffs this way. Full snapshots don't have to worry about updated accounts, so we can support them. Co-authored-by: Thomas E Lackey <telackey@bozemanpass.com> Reviewed-on: #15
2023-09-28 03:35:45 +00:00
40 changed files with 1222 additions and 453 deletions
@@ -89,3 +89,47 @@ jobs:
          pip install pytest
          pip install -r requirements.txt
          pytest -v -k test_basic_db
+
+  compliance-test:
+    name: Run compliance tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          path: ./plugeth-statediff
+      - uses: actions/checkout@v3
+        with:
+          repository: cerc-io/eth-statediff-compliance
+          ref: v0.1.0
+          path: ./eth-statediff-compliance
+          token: ${{ secrets.CICD_REPO_TOKEN }}
+      - uses: actions/setup-go@v4
+        with:
+          go-version-file: './eth-statediff-compliance/go.mod'
+          check-latest: true
+      - name: Install jq
+        run: apt-get update && apt-get install -yq jq
+      - name: Set up Gitea access token
+        env:
+          TOKEN: ${{ secrets.CICD_REPO_TOKEN }}
+        run: |
+          git config --global url."https://$TOKEN:@git.vdb.to/".insteadOf https://git.vdb.to/
+
+      - name: Update go.mod for dumpdiff-geth
+        working-directory: ./eth-statediff-compliance/
+        run: ./scripts/update-mod.sh ../plugeth-statediff dumpdiff-geth/
+      - name: Update go.mod for dumpdiff-plugeth
+        working-directory: ./eth-statediff-compliance/
+        run: ./scripts/update-mod.sh ../plugeth-statediff dumpdiff-plugeth/
+      - name: Update go.mod for dumpdiff-plugeth-parallel
+        working-directory: ./eth-statediff-compliance/
+        run: ./scripts/update-mod.sh ../plugeth-statediff dumpdiff-plugeth-parallel/
+      - name: Build tools
+        working-directory: ./eth-statediff-compliance/
+        run: make all
+      - name: Compare output of geth and plugeth
+        working-directory: ./eth-statediff-compliance/
+        run: ./scripts/compare-diffs.sh geth plugeth
+      - name: Compare output of geth and plugeth-parallel
+        working-directory: ./eth-statediff-compliance/
+        run: ./scripts/compare-diffs.sh geth plugeth-parallel
@@ -27,6 +27,7 @@ import (
 	"time"

 	iterutils "github.com/cerc-io/eth-iterator-utils"
+	"github.com/cerc-io/eth-iterator-utils/tracker"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -58,7 +59,7 @@ type Builder interface {
 	WriteStateDiff(Args, Params, sdtypes.StateNodeSink, sdtypes.IPLDSink) error
 }

-type StateDiffBuilder struct {
+type builder struct {
 	// state cache is safe for concurrent reads
 	stateCache     adapt.StateView
 	subtrieWorkers uint
@@ -88,8 +89,8 @@ func syncedAppender[T any](to *[]T) func(T) error {
 }

 // NewBuilder is used to create a statediff builder
-func NewBuilder(stateCache adapt.StateView) *StateDiffBuilder {
-	return &StateDiffBuilder{
+func NewBuilder(stateCache adapt.StateView) *builder {
+	return &builder{
 		stateCache:     stateCache,
 		subtrieWorkers: defaultSubtrieWorkers,
 	}
@@ -97,7 +98,7 @@ func NewBuilder(stateCache adapt.StateView) *StateDiffBuilder {

 // SetSubtrieWorkers sets the number of disjoint subtries to divide among parallel workers.
 // Passing 0 will reset this to the default value.
-func (sdb *StateDiffBuilder) SetSubtrieWorkers(n uint) {
+func (sdb *builder) SetSubtrieWorkers(n uint) {
 	if n == 0 {
 		n = defaultSubtrieWorkers
 	}
@@ -105,7 +106,7 @@ func (sdb *StateDiffBuilder) SetSubtrieWorkers(n uint) {
 }

 // BuildStateDiffObject builds a statediff object from two blocks and the provided parameters
-func (sdb *StateDiffBuilder) BuildStateDiffObject(args Args, params Params) (sdtypes.StateObject, error) {
+func (sdb *builder) BuildStateDiffObject(args Args, params Params) (sdtypes.StateObject, error) {
 	defer metrics.UpdateDuration(time.Now(), metrics.IndexerMetrics.BuildStateDiffObjectTimer)
 	var stateNodes []sdtypes.StateLeafNode
 	var iplds []sdtypes.IPLD
@@ -122,7 +123,7 @@ func (sdb *StateDiffBuilder) BuildStateDiffObject(args Args, params Params) (sdt
 }

 // WriteStateDiff writes a statediff object to output sinks
-func (sdb *StateDiffBuilder) WriteStateDiff(
+func (sdb *builder) WriteStateDiff(
 	args Args, params Params,
 	nodeSink sdtypes.StateNodeSink,
 	ipldSink sdtypes.IPLDSink,
@@ -141,14 +142,16 @@ func (sdb *StateDiffBuilder) WriteStateDiff(
 	subitersB := iterutils.SubtrieIterators(trieb.NodeIterator, uint(sdb.subtrieWorkers))

 	logger := log.New("hash", args.BlockHash, "number", args.BlockNumber)
-	// errgroup will cancel if any gr fails
+	// errgroup will cancel if any group fails
 	g, ctx := errgroup.WithContext(context.Background())
 	for i := uint(0); i < sdb.subtrieWorkers; i++ {
 		func(subdiv uint) {
 			g.Go(func() error {
 				a, b := subitersA[subdiv], subitersB[subdiv]
+				it := utils.NewSymmetricDifferenceIterator(a, b)
 				return sdb.processAccounts(ctx,
-					a, b, params.watchedAddressesLeafPaths,
+					it, &it.SymmDiffState,
+					params.watchedAddressesLeafPaths,
 					nodeSink, ipldSink, logger,
 				)
 			})
@@ -157,11 +160,60 @@ func (sdb *StateDiffBuilder) WriteStateDiff(
 	return g.Wait()
 }

-// processAccounts processes account creations and deletions, and returns a set of updated
-// existing accounts, indexed by leaf key.
-func (sdb *StateDiffBuilder) processAccounts(
+// WriteStateDiff writes a statediff object to output sinks
+func (sdb *builder) WriteStateSnapshot(
+	stateRoot common.Hash, params Params,
+	nodeSink sdtypes.StateNodeSink,
+	ipldSink sdtypes.IPLDSink,
+	tracker tracker.IteratorTracker,
+) error {
+	defer metrics.UpdateDuration(time.Now(), metrics.IndexerMetrics.WriteStateDiffTimer)
+	// Load tries for old and new states
+	tree, err := sdb.stateCache.OpenTrie(stateRoot)
+	if err != nil {
+		return fmt.Errorf("error opening new state trie: %w", err)
+	}
+
+	subiters, _, err := tracker.Restore(tree.NodeIterator)
+	if err != nil {
+		return fmt.Errorf("error restoring iterators: %w", err)
+	}
+	if len(subiters) != 0 {
+		// Completed iterators are not saved by the tracker, so restoring fewer than configured is ok,
+		// but having too many is a problem.
+		if len(subiters) > int(sdb.subtrieWorkers) {
+			return fmt.Errorf("restored too many iterators: expected %d, got %d",
+				sdb.subtrieWorkers, len(subiters))
+		}
+	} else {
+		subiters = iterutils.SubtrieIterators(tree.NodeIterator, uint(sdb.subtrieWorkers))
+		for i := range subiters {
+			subiters[i] = tracker.Tracked(subiters[i])
+		}
+	}
+	// errgroup will cancel if any group fails
+	g, ctx := errgroup.WithContext(context.Background())
+	for i := range subiters {
+		func(subdiv uint) {
+			g.Go(func() error {
+				symdiff := utils.AlwaysBState()
+				return sdb.processAccounts(ctx,
+					subiters[subdiv], &symdiff,
+					params.watchedAddressesLeafPaths,
+					nodeSink, ipldSink, log.DefaultLogger,
+				)
+			})
+		}(uint(i))
+	}
+	return g.Wait()
+}
+
+// processAccounts processes account creations, deletions, and updates
+// the NodeIterator and SymmDiffIterator instances should refer to the same object, will only be used
+func (sdb *builder) processAccounts(
 	ctx context.Context,
-	a, b trie.NodeIterator, watchedAddressesLeafPaths [][]byte,
+	it trie.NodeIterator, symdiff *utils.SymmDiffState,
+	watchedAddressesLeafPaths [][]byte,
 	nodeSink sdtypes.StateNodeSink, ipldSink sdtypes.IPLDSink,
 	logger log.Logger,
 ) error {
@@ -171,9 +223,7 @@ func (sdb *StateDiffBuilder) processAccounts(

 	updates := make(accountUpdateMap)
 	// Cache the RLP of the previous node. When we hit a value node this will be the parent blob.
-	var prevBlob []byte
-	it, itCount := utils.NewSymmetricDifferenceIterator(a, b)
-	prevBlob = it.NodeBlob()
+	var prevBlob = it.NodeBlob()
 	for it.Next(true) {
 		select {
 		case <-ctx.Done():
@@ -185,7 +235,7 @@ func (sdb *StateDiffBuilder) processAccounts(
 		if !isWatchedPathPrefix(watchedAddressesLeafPaths, it.Path()) {
 			continue
 		}
-		if it.FromA() { // Node exists in the old trie
+		if symdiff.FromA() { // Node exists in the old trie
 			if it.Leaf() {
 				var account types.StateAccount
 				if err := rlp.DecodeBytes(it.LeafBlob(), &account); err != nil {
@@ -194,7 +244,7 @@ func (sdb *StateDiffBuilder) processAccounts(
 				leafKey := make([]byte, len(it.LeafKey()))
 				copy(leafKey, it.LeafKey())

-				if it.CommonPath() {
+				if symdiff.CommonPath() {
 					// If B also contains this leaf node, this is the old state of an updated account.
 					if update, ok := updates[string(leafKey)]; ok {
 						update.oldRoot = account.Root
@@ -212,14 +262,14 @@ func (sdb *StateDiffBuilder) processAccounts(
 			}
 			continue
 		}
-		// Node exists in the new trie
+		// Node exists in the new trie (B)
 		if it.Leaf() {
 			accountW, err := sdb.decodeStateLeaf(it, prevBlob)
 			if err != nil {
 				return err
 			}

-			if it.CommonPath() {
+			if symdiff.CommonPath() {
 				// If A also contains this leaf node, this is the new state of an updated account.
 				if update, ok := updates[string(accountW.LeafKey)]; ok {
 					update.new = *accountW
@@ -232,42 +282,41 @@ func (sdb *StateDiffBuilder) processAccounts(
 					return err
 				}
 			}
-		} else {
-			// New trie nodes will be written to blockstore only.
-			// Reminder: this includes leaf nodes, since the geth iterator.Leaf() actually
-			// signifies a "value" node.
-			if it.Hash() == zeroHash {
-				continue
-			}
-			// TODO - this can be handled when value node is (craeted?)
-			nodeVal := make([]byte, len(it.NodeBlob()))
-			copy(nodeVal, it.NodeBlob())
-			// if doing a selective diff, we need to ensure this is a watched path
-			if len(watchedAddressesLeafPaths) > 0 {
-				var elements []interface{}
-				if err := rlp.DecodeBytes(nodeVal, &elements); err != nil {
-					return err
-				}
-				ok, err := isLeaf(elements)
-				if err != nil {
-					return err
-				}
-				if ok {
-					partialPath := utils.CompactToHex(elements[0].([]byte))
-					valueNodePath := append(it.Path(), partialPath...)
-					if !isWatchedPath(watchedAddressesLeafPaths, valueNodePath) {
-						continue
-					}
-				}
-			}
-			if err := ipldSink(sdtypes.IPLD{
-				CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, it.Hash().Bytes()).String(),
-				Content: nodeVal,
-			}); err != nil {
+			continue
+		}
+		// New inner trie nodes will be written to blockstore only.
+		// Reminder: this includes leaf nodes, since the geth iterator.Leaf() actually
+		// signifies a "value" node.
+		if it.Hash() == zeroHash {
+			continue
+		}
+		nodeVal := make([]byte, len(it.NodeBlob()))
+		copy(nodeVal, it.NodeBlob())
+		// if doing a selective diff, we need to ensure this is a watched path
+		if len(watchedAddressesLeafPaths) > 0 {
+			var elements []interface{}
+			if err := rlp.DecodeBytes(nodeVal, &elements); err != nil {
 				return err
 			}
-			prevBlob = nodeVal
+			ok, err := isLeaf(elements)
+			if err != nil {
+				return err
+			}
+			if ok {
+				partialPath := utils.CompactToHex(elements[0].([]byte))
+				valueNodePath := append(it.Path(), partialPath...)
+				if !isWatchedPath(watchedAddressesLeafPaths, valueNodePath) {
+					continue
+				}
+			}
 		}
+		if err := ipldSink(sdtypes.IPLD{
+			CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, it.Hash().Bytes()).String(),
+			Content: nodeVal,
+		}); err != nil {
+			return err
+		}
+		prevBlob = nodeVal
 	}

 	for key, update := range updates {
@@ -287,12 +336,10 @@ func (sdb *StateDiffBuilder) processAccounts(
 			return err
 		}
 	}
-
-	metrics.IndexerMetrics.DifferenceIteratorCounter.Inc(int64(*itCount))
 	return it.Error()
 }

-func (sdb *StateDiffBuilder) processAccountDeletion(
+func (sdb *builder) processAccountDeletion(
 	leafKey []byte, account types.StateAccount, nodeSink sdtypes.StateNodeSink,
 ) error {
 	diff := sdtypes.StateLeafNode{
@@ -309,7 +356,7 @@ func (sdb *StateDiffBuilder) processAccountDeletion(
 	return nodeSink(diff)
 }

-func (sdb *StateDiffBuilder) processAccountCreation(
+func (sdb *builder) processAccountCreation(
 	accountW *sdtypes.AccountWrapper, ipldSink sdtypes.IPLDSink, nodeSink sdtypes.StateNodeSink,
 ) error {
 	diff := sdtypes.StateLeafNode{
@@ -340,7 +387,7 @@ func (sdb *StateDiffBuilder) processAccountCreation(
 // decodes account at leaf and encodes RLP data to CID
 // reminder: it.Leaf() == true when the iterator is positioned at a "value node" (which is not something
 // that actually exists in an MMPT), therefore we pass the parent node blob as the leaf RLP.
-func (sdb *StateDiffBuilder) decodeStateLeaf(it trie.NodeIterator, parentBlob []byte) (*sdtypes.AccountWrapper, error) {
+func (sdb *builder) decodeStateLeaf(it trie.NodeIterator, parentBlob []byte) (*sdtypes.AccountWrapper, error) {
 	var account types.StateAccount
 	if err := rlp.DecodeBytes(it.LeafBlob(), &account); err != nil {
 		return nil, fmt.Errorf("error decoding account at leaf key %x: %w", it.LeafKey(), err)
@@ -357,7 +404,7 @@ func (sdb *StateDiffBuilder) decodeStateLeaf(it trie.NodeIterator, parentBlob []

 // processStorageCreations processes the storage node records for a newly created account
 // i.e. it returns all the storage nodes at this state, since there is no previous state.
-func (sdb *StateDiffBuilder) processStorageCreations(
+func (sdb *builder) processStorageCreations(
 	sr common.Hash, storageSink sdtypes.StorageNodeSink, ipldSink sdtypes.IPLDSink,
 ) error {
 	defer metrics.UpdateDuration(time.Now(), metrics.IndexerMetrics.ProcessStorageCreationsTimer)
@@ -394,8 +441,9 @@ func (sdb *StateDiffBuilder) processStorageCreations(
 	return it.Error()
 }

-// processStorageUpdates builds the storage diff node objects for all nodes that exist in a different state at B than A
-func (sdb *StateDiffBuilder) processStorageUpdates(
+// processStorageUpdates builds the storage diff node objects for all nodes that exist in a
+// different state at B than A
+func (sdb *builder) processStorageUpdates(
 	oldroot common.Hash, newroot common.Hash,
 	storageSink sdtypes.StorageNodeSink,
 	ipldSink sdtypes.IPLDSink,
@@ -416,7 +464,7 @@ func (sdb *StateDiffBuilder) processStorageUpdates(

 	var prevBlob []byte
 	a, b := oldTrie.NodeIterator(nil), newTrie.NodeIterator(nil)
-	it, _ := utils.NewSymmetricDifferenceIterator(a, b)
+	it := utils.NewSymmetricDifferenceIterator(a, b)
 	for it.Next(true) {
 		if it.FromA() {
 			if it.Leaf() && !it.CommonPath() {
@@ -457,7 +505,7 @@ func (sdb *StateDiffBuilder) processStorageUpdates(
 }

 // processRemovedAccountStorage builds the "removed" diffs for all the storage nodes for a destroyed account
-func (sdb *StateDiffBuilder) processRemovedAccountStorage(
+func (sdb *builder) processRemovedAccountStorage(
 	sr common.Hash, storageSink sdtypes.StorageNodeSink,
 ) error {
 	defer metrics.UpdateDuration(time.Now(), metrics.IndexerMetrics.ProcessRemovedAccountStorageTimer)
@@ -491,7 +539,7 @@ func (sdb *StateDiffBuilder) processRemovedAccountStorage(
 // decodes slot at leaf and encodes RLP data to CID
 // reminder: it.Leaf() == true when the iterator is positioned at a "value node" (which is not something
 // that actually exists in an MMPT), therefore we pass the parent node blob as the leaf RLP.
-func (sdb *StateDiffBuilder) decodeStorageLeaf(it trie.NodeIterator, parentBlob []byte) sdtypes.StorageLeafNode {
+func (sdb *builder) decodeStorageLeaf(it trie.NodeIterator, parentBlob []byte) sdtypes.StorageLeafNode {
 	leafKey := make([]byte, len(it.LeafKey()))
 	copy(leafKey, it.LeafKey())
 	value := make([]byte, len(it.LeafBlob()))
@@ -0,0 +1,538 @@
+package statediff_test
+
+import (
+	"testing"
+
+	statediff "github.com/cerc-io/plugeth-statediff"
+	"github.com/cerc-io/plugeth-statediff/indexer/ipld"
+	"github.com/cerc-io/plugeth-statediff/test_helpers"
+	sdtypes "github.com/cerc-io/plugeth-statediff/types"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func TestBuilderSnapshot(t *testing.T) {
+	blocks, chain := test_helpers.MakeChain(3, test_helpers.Genesis, test_helpers.TestChainGen)
+	contractLeafKey = test_helpers.AddressToLeafKey(test_helpers.ContractAddr)
+	defer chain.Stop()
+	block0 = test_helpers.Genesis
+	block1 = blocks[0]
+	block2 = blocks[1]
+	block3 = blocks[2]
+	params := statediff.Params{}
+
+	tests := []test_helpers.SnapshotTestCase{
+		{
+			"testEmptyDiff",
+			common.Hash{},
+			&sdtypes.StateObject{
+				Nodes: emptyDiffs,
+			},
+		},
+		{
+			"testBlock0",
+			//10000 transferred from testBankAddress to account1Addr
+			block0.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: bankAccountAtBlock0,
+							LeafKey: test_helpers.BankLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock0LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock0LeafNode)).String(),
+						Content: bankAccountAtBlock0LeafNode,
+					},
+				},
+			},
+		},
+		{
+			"testBlock1",
+			//10000 transferred from testBankAddress to account1Addr
+			block1.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: bankAccountAtBlock1,
+							LeafKey: test_helpers.BankLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock1LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: minerAccountAtBlock1,
+							LeafKey: minerLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(minerAccountAtBlock1LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account1AtBlock1,
+							LeafKey: test_helpers.Account1LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock1LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(block1BranchRootNode)).String(),
+						Content: block1BranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock1LeafNode)).String(),
+						Content: bankAccountAtBlock1LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(minerAccountAtBlock1LeafNode)).String(),
+						Content: minerAccountAtBlock1LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock1LeafNode)).String(),
+						Content: account1AtBlock1LeafNode,
+					},
+				},
+			},
+		},
+		{
+			"testBlock2",
+			//1000 transferred from testBankAddress to account1Addr
+			//1000 transferred from account1Addr to account2Addr
+			block2.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: bankAccountAtBlock2,
+							LeafKey: test_helpers.BankLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: minerAccountAtBlock2,
+							LeafKey: minerLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(minerAccountAtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account1AtBlock2,
+							LeafKey: test_helpers.Account1LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: contractAccountAtBlock2,
+							LeafKey: contractLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock2LeafNode)).String()},
+						StorageDiff: []sdtypes.StorageLeafNode{
+							{
+								Removed: false,
+								Value:   slot0StorageValue,
+								LeafKey: slot0StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+							},
+							{
+								Removed: false,
+								Value:   slot1StorageValue,
+								LeafKey: slot1StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+							},
+						},
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account2AtBlock2,
+							LeafKey: test_helpers.Account2LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account2AtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.RawBinary, test_helpers.CodeHash.Bytes()).String(),
+						Content: test_helpers.ByteCodeAfterDeployment,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(block2BranchRootNode)).String(),
+						Content: block2BranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock2LeafNode)).String(),
+						Content: bankAccountAtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(minerAccountAtBlock2LeafNode)).String(),
+						Content: minerAccountAtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String(),
+						Content: account1AtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock2LeafNode)).String(),
+						Content: contractAccountAtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(block2StorageBranchRootNode)).String(),
+						Content: block2StorageBranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+						Content: slot0StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+						Content: slot1StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account2AtBlock2LeafNode)).String(),
+						Content: account2AtBlock2LeafNode,
+					},
+				},
+			},
+		},
+		{
+			"testBlock3",
+			//the contract's storage is changed
+			//and the block is mined by account 2
+			block3.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: minerAccountAtBlock2,
+							LeafKey: minerLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(minerAccountAtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account1AtBlock2,
+							LeafKey: test_helpers.Account1LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: bankAccountAtBlock3,
+							LeafKey: test_helpers.BankLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock3LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: contractAccountAtBlock3,
+							LeafKey: contractLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock3LeafNode)).String()},
+						StorageDiff: []sdtypes.StorageLeafNode{
+
+							{
+								Removed: false,
+								Value:   slot0StorageValue,
+								LeafKey: slot0StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+							},
+							{
+								Removed: false,
+								Value:   slot1StorageValue,
+								LeafKey: slot1StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+							},
+
+							{
+								Removed: false,
+								Value:   slot3StorageValue,
+								LeafKey: slot3StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot3StorageLeafNode)).String(),
+							},
+						},
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account2AtBlock3,
+							LeafKey: test_helpers.Account2LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account2AtBlock3LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.RawBinary, test_helpers.CodeHash.Bytes()).String(),
+						Content: test_helpers.ByteCodeAfterDeployment,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(minerAccountAtBlock2LeafNode)).String(),
+						Content: minerAccountAtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String(),
+						Content: account1AtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+						Content: slot0StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+						Content: slot1StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(block3BranchRootNode)).String(),
+						Content: block3BranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(bankAccountAtBlock3LeafNode)).String(),
+						Content: bankAccountAtBlock3LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock3LeafNode)).String(),
+						Content: contractAccountAtBlock3LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(block3StorageBranchRootNode)).String(),
+						Content: block3StorageBranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot3StorageLeafNode)).String(),
+						Content: slot3StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account2AtBlock3LeafNode)).String(),
+						Content: account2AtBlock3LeafNode,
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		test_helpers.RunStateSnapshot(t, chain.StateCache(), test, params)
+	}
+}
+
+func TestBuilderSnapshotWithWatchedAddressList(t *testing.T) {
+	blocks, chain := test_helpers.MakeChain(3, test_helpers.Genesis, test_helpers.TestChainGen)
+	contractLeafKey = test_helpers.AddressToLeafKey(test_helpers.ContractAddr)
+	defer chain.Stop()
+	block0 = test_helpers.Genesis
+	block1 = blocks[0]
+	block2 = blocks[1]
+	block3 = blocks[2]
+	params := statediff.Params{
+		WatchedAddresses: []common.Address{test_helpers.Account1Addr, test_helpers.ContractAddr},
+	}
+	params.ComputeWatchedAddressesLeafPaths()
+
+	var tests = []test_helpers.SnapshotTestCase{
+		{
+			"testBlock0",
+			//10000 transferred from testBankAddress to account1Addr
+			block0.Root(),
+			&sdtypes.StateObject{
+				Nodes: emptyDiffs,
+			},
+		},
+		{
+			"testBlock1",
+			//10000 transferred from testBankAddress to account1Addr
+			block1.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account1AtBlock1,
+							LeafKey: test_helpers.Account1LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock1LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(block1BranchRootNode)).String(),
+						Content: block1BranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock1LeafNode)).String(),
+						Content: account1AtBlock1LeafNode,
+					},
+				},
+			},
+		},
+		{
+			"testBlock2",
+			//1000 transferred from testBankAddress to account1Addr
+			//1000 transferred from account1Addr to account2Addr
+			block2.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: contractAccountAtBlock2,
+							LeafKey: contractLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock2LeafNode)).String(),
+						},
+						StorageDiff: []sdtypes.StorageLeafNode{
+							{
+								Removed: false,
+								Value:   slot0StorageValue,
+								LeafKey: slot0StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+							},
+							{
+								Removed: false,
+								Value:   slot1StorageValue,
+								LeafKey: slot1StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+							},
+						},
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account1AtBlock2,
+							LeafKey: test_helpers.Account1LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.RawBinary, test_helpers.CodeHash.Bytes()).String(),
+						Content: test_helpers.ByteCodeAfterDeployment,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(block2BranchRootNode)).String(),
+						Content: block2BranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock2LeafNode)).String(),
+						Content: contractAccountAtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(block2StorageBranchRootNode)).String(),
+						Content: block2StorageBranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+						Content: slot0StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+						Content: slot1StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String(),
+						Content: account1AtBlock2LeafNode,
+					},
+				},
+			},
+		},
+		{
+			"testBlock3",
+			//the contract's storage is changed
+			//and the block is mined by account 2
+			block3.Root(),
+			&sdtypes.StateObject{
+				Nodes: []sdtypes.StateLeafNode{
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: account1AtBlock2,
+							LeafKey: test_helpers.Account1LeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String()},
+						StorageDiff: emptyStorage,
+					},
+					{
+						Removed: false,
+						AccountWrapper: sdtypes.AccountWrapper{
+							Account: contractAccountAtBlock3,
+							LeafKey: contractLeafKey,
+							CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock3LeafNode)).String()},
+						StorageDiff: []sdtypes.StorageLeafNode{
+							{
+								Removed: false,
+								Value:   slot0StorageValue,
+								LeafKey: slot0StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+							},
+							{
+								Removed: false,
+								Value:   slot1StorageValue,
+								LeafKey: slot1StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+							},
+							{
+								Removed: false,
+								Value:   slot3StorageValue,
+								LeafKey: slot3StorageKey.Bytes(),
+								CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot3StorageLeafNode)).String(),
+							},
+						},
+					},
+				},
+				IPLDs: []sdtypes.IPLD{
+					{
+						CID:     ipld.Keccak256ToCid(ipld.RawBinary, test_helpers.CodeHash.Bytes()).String(),
+						Content: test_helpers.ByteCodeAfterDeployment,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(account1AtBlock2LeafNode)).String(),
+						Content: account1AtBlock2LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot0StorageLeafNode)).String(),
+						Content: slot0StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot1StorageLeafNode)).String(),
+						Content: slot1StorageLeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(block3BranchRootNode)).String(),
+						Content: block3BranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStateTrie, crypto.Keccak256(contractAccountAtBlock3LeafNode)).String(),
+						Content: contractAccountAtBlock3LeafNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(block3StorageBranchRootNode)).String(),
+						Content: block3StorageBranchRootNode,
+					},
+					{
+						CID:     ipld.Keccak256ToCid(ipld.MEthStorageTrie, crypto.Keccak256(slot3StorageLeafNode)).String(),
+						Content: slot3StorageLeafNode,
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		test_helpers.RunStateSnapshot(t, chain.StateCache(), test, params)
+	}
+}
@@ -503,7 +503,7 @@ func TestBuilder(t *testing.T) {
 	block3 = blocks[2]
 	params := statediff.Params{}

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testEmptyDiff",
 			statediff.Args{
@@ -795,7 +795,7 @@ func TestBuilder(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block0: bankAccountAtBlock0LeafNode,
 		block1: block1BranchRootNode,
@@ -817,7 +817,7 @@ func TestBuilderWithWatchedAddressList(t *testing.T) {
 	}
 	params.ComputeWatchedAddressesLeafPaths()

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testEmptyDiff",
 			statediff.Args{
@@ -1009,7 +1009,7 @@ func TestBuilderWithWatchedAddressList(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block0: bankAccountAtBlock0LeafNode,
 		block1: block1BranchRootNode,
@@ -1028,7 +1028,7 @@ func TestBuilderWithRemovedAccountAndStorage(t *testing.T) {
 	block6 = blocks[5]
 	params := statediff.Params{}

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		// blocks 0-3 are the same as in TestBuilderWithIntermediateNodes
 		{
 			"testBlock4",
@@ -1260,7 +1260,7 @@ func TestBuilderWithRemovedAccountAndStorage(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block4: block4BranchRootNode,
 		block5: block5BranchRootNode,
@@ -1281,7 +1281,7 @@ func TestBuilderWithRemovedNonWatchedAccount(t *testing.T) {
 	}
 	params.ComputeWatchedAddressesLeafPaths()

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testBlock4",
 			statediff.Args{
@@ -1395,7 +1395,7 @@ func TestBuilderWithRemovedNonWatchedAccount(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block4: block4BranchRootNode,
 		block5: block5BranchRootNode,
@@ -1416,7 +1416,7 @@ func TestBuilderWithRemovedWatchedAccount(t *testing.T) {
 	}
 	params.ComputeWatchedAddressesLeafPaths()

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testBlock4",
 			statediff.Args{
@@ -1599,7 +1599,7 @@ func TestBuilderWithRemovedWatchedAccount(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block4: block4BranchRootNode,
 		block5: block5BranchRootNode,
@@ -1700,7 +1700,7 @@ func TestBuilderWithMovedAccount(t *testing.T) {
 	block2 = blocks[1]
 	params := statediff.Params{}

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testBlock1",
 			statediff.Args{
@@ -1827,7 +1827,7 @@ func TestBuilderWithMovedAccount(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block1: block01BranchRootNode,
 		block2: bankAccountAtBlock02LeafNode,
@@ -2088,7 +2088,7 @@ func TestBuilderWithInternalizedLeafNode(t *testing.T) {
 	block3 = blocks[2]
 	params := statediff.Params{}

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testEmptyDiff",
 			statediff.Args{
@@ -2354,7 +2354,7 @@ func TestBuilderWithInternalizedLeafNode(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block1: block1bBranchRootNode,
 		block2: block2bBranchRootNode,
@@ -2377,7 +2377,7 @@ func TestBuilderWithInternalizedLeafNodeAndWatchedAddress(t *testing.T) {
 	}
 	params.ComputeWatchedAddressesLeafPaths()

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		{
 			"testEmptyDiff",
 			statediff.Args{
@@ -2556,7 +2556,7 @@ func TestBuilderWithInternalizedLeafNodeAndWatchedAddress(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block1: block1bBranchRootNode,
 		block2: block2bBranchRootNode,
@@ -48,16 +48,16 @@ type Config struct {
 	SubtrieWorkers uint
 	// Should the statediff service wait until geth has synced to the head of the blockchain?
 	WaitForSync bool
-	// Context used during DB initialization
+	// Context passed to all DB method calls
 	Context context.Context
 }

 // Params contains config parameters for the state diff builder
 type Params struct {
-	IncludeBlock              bool
+	IncludeBlock              bool // TODO: not used in write-requests
 	IncludeReceipts           bool
 	IncludeTD                 bool
-	IncludeCode               bool
+	IncludeCode               bool // TODO: not used by anything?
 	WatchedAddresses          []common.Address
 	watchedAddressesLeafPaths [][]byte
 }
@@ -124,8 +124,8 @@ require (
 )

 replace (
-	github.com/cerc-io/eth-iterator-utils => git.vdb.to/cerc-io/eth-iterator-utils v0.1.1
-	github.com/cerc-io/eth-testing => git.vdb.to/cerc-io/eth-testing v0.2.1
+	github.com/cerc-io/eth-iterator-utils => git.vdb.to/cerc-io/eth-iterator-utils v0.1.2
+	github.com/cerc-io/eth-testing => git.vdb.to/cerc-io/eth-testing v0.3.1
 	github.com/ethereum/go-ethereum => git.vdb.to/cerc-io/plugeth v0.0.0-20230808125822-691dc334fab1
 	github.com/openrelayxyz/plugeth-utils => git.vdb.to/cerc-io/plugeth-utils v0.0.0-20230706160122-cd41de354c46
 )
@@ -1,8 +1,8 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
-git.vdb.to/cerc-io/eth-iterator-utils v0.1.1 h1:AGen4U2GaYJVzPjEo3U+GPczSfOUEMkM1nWTM+cq5Dk=
-git.vdb.to/cerc-io/eth-iterator-utils v0.1.1/go.mod h1:uiocO9elfDe78kd3c/VZ2in26V+gyXJuN+sdTxK4Xag=
-git.vdb.to/cerc-io/eth-testing v0.2.1 h1:IZAX7DVgzPkSmu1xdKZ5aOemdEYbvtgae7GUl/TUNtQ=
-git.vdb.to/cerc-io/eth-testing v0.2.1/go.mod h1:qdvpc/W1xvf2MKx3rMOqvFvYaYIHG77Z1g0lwsmw0Uk=
+git.vdb.to/cerc-io/eth-iterator-utils v0.1.2 h1:PdMR5B9wrQSYuYpFhN+9Kc8AEZ0pTt5eKCmu8oCtFcY=
+git.vdb.to/cerc-io/eth-iterator-utils v0.1.2/go.mod h1:OvXbdWbZ5viBXC/Ui1EkhsSmGB+AUX+TjGa3UDAfjfg=
+git.vdb.to/cerc-io/eth-testing v0.3.1 h1:sPnlMev6oEgTjsW7GtUkSsjKNG/+X6P9q0izSejLGpM=
+git.vdb.to/cerc-io/eth-testing v0.3.1/go.mod h1:qdvpc/W1xvf2MKx3rMOqvFvYaYIHG77Z1g0lwsmw0Uk=
 git.vdb.to/cerc-io/plugeth v0.0.0-20230808125822-691dc334fab1 h1:KLjxHwp9Zp7xhECccmJS00RiL+VwTuUGLU7qeIctg8g=
 git.vdb.to/cerc-io/plugeth v0.0.0-20230808125822-691dc334fab1/go.mod h1:cYXZu70+6xmDgIgrTD81GPasv16piiAFJnKyAbwVPMU=
 git.vdb.to/cerc-io/plugeth-utils v0.0.0-20230706160122-cd41de354c46 h1:KYcbbne/RXd7AuxbUd/3hgk1jPN+33k2CKiNsUsMCC0=
@@ -33,7 +33,16 @@ import (
 )

 // NewStateDiffIndexer creates and returns an implementation of the StateDiffIndexer interface.
-func NewStateDiffIndexer(ctx context.Context, chainConfig *params.ChainConfig, nodeInfo node.Info, config interfaces.Config) (sql.Database, interfaces.StateDiffIndexer, error) {
+func NewStateDiffIndexer(
+	ctx context.Context,
+	chainConfig *params.ChainConfig,
+	nodeInfo node.Info,
+	config interfaces.Config,
+) (
+	sql.Database,
+	interfaces.StateDiffIndexer,
+	error,
+) {
 	switch config.Type() {
 	case shared.FILE:
 		log.Info("Starting statediff service in SQL file writing mode")
@@ -41,8 +50,7 @@ func NewStateDiffIndexer(ctx context.Context, chainConfig *params.ChainConfig, n
 		if !ok {
 			return nil, nil, fmt.Errorf("file config is not the correct type: got %T, expected %T", config, file.Config{})
 		}
-		fc.NodeInfo = nodeInfo
-		ind, err := file.NewStateDiffIndexer(chainConfig, fc)
+		ind, err := file.NewStateDiffIndexer(chainConfig, fc, nodeInfo)
 		return nil, ind, err
 	case shared.POSTGRES:
 		log.Info("Starting statediff service in Postgres writing mode")
@@ -19,26 +19,55 @@ package dump
 import (
 	"fmt"
 	"io"
+	"math/big"

 	"github.com/cerc-io/plugeth-statediff/indexer/ipld"
-
 	"github.com/cerc-io/plugeth-statediff/indexer/models"
+	"github.com/cerc-io/plugeth-statediff/utils/log"
 )

 // BatchTx wraps a void with the state necessary for building the tx concurrently during trie difference iteration
 type BatchTx struct {
-	BlockNumber string
-	dump        io.Writer
-	quit        chan struct{}
-	iplds       chan models.IPLDModel
-	ipldCache   models.IPLDBatch
-
-	submit func(blockTx *BatchTx, err error) error
+	blockNum  string
+	dump      io.Writer
+	quit      chan struct{}
+	iplds     chan models.IPLDModel
+	ipldCache models.IPLDBatch
 }

-// Submit satisfies indexer.AtomicTx
-func (tx *BatchTx) Submit(err error) error {
-	return tx.submit(tx, err)
+func NewBatch(number *big.Int, dest io.Writer) *BatchTx {
+	batch := &BatchTx{
+		blockNum:  number.String(),
+		dump:      dest,
+		iplds:     make(chan models.IPLDModel),
+		quit:      make(chan struct{}),
+		ipldCache: models.IPLDBatch{},
+	}
+	go batch.cache()
+	return batch
+}
+
+func (self *BatchTx) Submit() error {
+	close(self.quit)
+	close(self.iplds)
+
+	if err := self.flush(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (tx *BatchTx) BlockNumber() string {
+	return tx.blockNum
+}
+
+func (tx *BatchTx) RollbackOnFailure(err error) {
+	if p := recover(); p != nil {
+		log.Info("panic detected before tx submission, but rollback not supported", "panic", p)
+		panic(p)
+	} else if err != nil {
+		log.Info("error detected before tx submission, but rollback not supported", "error", err)
+	}
 }

 func (tx *BatchTx) flush() error {
@@ -65,7 +94,7 @@ func (tx *BatchTx) cache() {

 func (tx *BatchTx) cacheDirect(key string, value []byte) {
 	tx.iplds <- models.IPLDModel{
-		BlockNumber: tx.BlockNumber,
+		BlockNumber: tx.BlockNumber(),
 		Key:         key,
 		Data:        value,
 	}
@@ -73,7 +102,7 @@ func (tx *BatchTx) cacheDirect(key string, value []byte) {

 func (tx *BatchTx) cacheIPLD(i ipld.IPLD) {
 	tx.iplds <- models.IPLDModel{
-		BlockNumber: tx.BlockNumber,
+		BlockNumber: tx.BlockNumber(),
 		Key:         i.Cid().String(),
 		Data:        i.RawData(),
 	}
@@ -17,6 +17,7 @@
 package dump

 import (
+	"context"
 	"encoding/hex"
 	"fmt"
 	"io"
@@ -37,7 +38,6 @@ import (
 	"github.com/cerc-io/plugeth-statediff/indexer/models"
 	"github.com/cerc-io/plugeth-statediff/indexer/shared"
 	sdtypes "github.com/cerc-io/plugeth-statediff/types"
-	"github.com/cerc-io/plugeth-statediff/utils/log"
 )

 var _ interfaces.StateDiffIndexer = &StateDiffIndexer{}
@@ -62,7 +62,7 @@ func (sdi *StateDiffIndexer) ReportDBMetrics(time.Duration, <-chan bool) {}
 // PushBlock pushes and indexes block data in sql, except state & storage nodes (includes header, uncles, transactions & receipts)
 // Returns an initiated DB transaction which must be Closed via defer to commit or rollback
 func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receipts, totalDifficulty *big.Int) (interfaces.Batch, error) {
-	start, t := time.Now(), time.Now()
+	t := time.Now()
 	blockHash := block.Hash()
 	blockHashStr := blockHash.String()
 	height := block.NumberU64()
@@ -74,7 +74,7 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	}

 	// Generate the block iplds
-	headerNode, txNodes, rctNodes, logNodes, err := ipld.FromBlockAndReceipts(block, receipts)
+	txNodes, rctNodes, logNodes, err := ipld.FromBlockAndReceipts(block, receipts)
 	if err != nil {
 		return nil, fmt.Errorf("error creating IPLD nodes from block and receipts: %v", err)
 	}
@@ -91,49 +91,17 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	} else {
 		reward = shared.CalcEthBlockReward(block.Header(), block.Uncles(), block.Transactions(), receipts)
 	}
-	t = time.Now()

-	blockTx := &BatchTx{
-		BlockNumber: block.Number().String(),
-		dump:        sdi.dump,
-		iplds:       make(chan models.IPLDModel),
-		quit:        make(chan struct{}),
-		ipldCache:   models.IPLDBatch{},
-		submit: func(self *BatchTx, err error) error {
-			close(self.quit)
-			close(self.iplds)
-			tDiff := time.Since(t)
-			metrics.IndexerMetrics.StateStoreCodeProcessingTimer.Update(tDiff)
-			traceMsg += fmt.Sprintf("state, storage, and code storage processing time: %s\r\n", tDiff.String())
-			t = time.Now()
-			if err := self.flush(); err != nil {
-				traceMsg += fmt.Sprintf(" TOTAL PROCESSING DURATION: %s\r\n", time.Since(start).String())
-				log.Debug(traceMsg)
-				return err
-			}
-			tDiff = time.Since(t)
-			metrics.IndexerMetrics.PostgresCommitTimer.Update(tDiff)
-			traceMsg += fmt.Sprintf("postgres transaction commit duration: %s\r\n", tDiff.String())
-			traceMsg += fmt.Sprintf(" TOTAL PROCESSING DURATION: %s\r\n", time.Since(start).String())
-			log.Debug(traceMsg)
-			return err
-		},
-	}
-	go blockTx.cache()
-
-	tDiff := time.Since(t)
-	metrics.IndexerMetrics.FreePostgresTimer.Update(tDiff)
-
-	traceMsg += fmt.Sprintf("time spent waiting for free postgres tx: %s:\r\n", tDiff.String())
+	blockTx := NewBatch(block.Number(), sdi.dump)
 	t = time.Now()

 	// Publish and index header, collect headerID
 	var headerID string
-	headerID, err = sdi.processHeader(blockTx, block.Header(), headerNode, reward, totalDifficulty)
+	headerID, err = sdi.PushHeader(blockTx, block.Header(), reward, totalDifficulty)
 	if err != nil {
 		return nil, err
 	}
-	tDiff = time.Since(t)
+	tDiff := time.Since(t)
 	metrics.IndexerMetrics.HeaderProcessingTimer.Update(tDiff)
 	traceMsg += fmt.Sprintf("header processing time: %s\r\n", tDiff.String())
 	t = time.Now()
@@ -167,9 +135,17 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	return blockTx, err
 }

-// processHeader publishes and indexes a header IPLD in Postgres
+// PushHeader publishes and indexes a header IPLD in Postgres
 // it returns the headerID
-func (sdi *StateDiffIndexer) processHeader(tx *BatchTx, header *types.Header, headerNode ipld.IPLD, reward, td *big.Int) (string, error) {
+func (sdi *StateDiffIndexer) PushHeader(batch interfaces.Batch, header *types.Header, reward, td *big.Int) (string, error) {
+	tx, ok := batch.(*BatchTx)
+	if !ok {
+		return "", fmt.Errorf("sql: batch is expected to be of type %T, got %T", &BatchTx{}, batch)
+	}
+	headerNode, err := ipld.NewEthHeader(header)
+	if err != nil {
+		return "", err
+	}
 	tx.cacheIPLD(headerNode)

 	headerID := header.Hash().String()
@@ -189,7 +165,7 @@ func (sdi *StateDiffIndexer) processHeader(tx *BatchTx, header *types.Header, he
 		Coinbase:        header.Coinbase.String(),
 		Canonical:       true,
 	}
-	_, err := fmt.Fprintf(sdi.dump, "%+v\r\n", mod)
+	_, err = fmt.Fprintf(sdi.dump, "%+v\r\n", mod)
 	return headerID, err
 }

@@ -344,7 +320,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 		// short circuit if it is a Removed node
 		// this assumes the db has been initialized and a ipld.blocks entry for the Removed node is present
 		stateModel = models.StateNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			CID:         shared.RemovedNodeStateCID,
@@ -352,7 +328,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 		}
 	} else {
 		stateModel = models.StateNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			CID:         stateNode.AccountWrapper.CID,
@@ -375,7 +351,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 			// short circuit if it is a Removed node
 			// this assumes the db has been initialized and a ipld.blocks entry for the Removed node is present
 			storageModel := models.StorageNodeModel{
-				BlockNumber: tx.BlockNumber,
+				BlockNumber: tx.BlockNumber(),
 				HeaderID:    headerID,
 				StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 				StorageKey:  common.BytesToHash(storageNode.LeafKey).String(),
@@ -388,7 +364,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 			continue
 		}
 		storageModel := models.StorageNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			StorageKey:  common.BytesToHash(storageNode.LeafKey).String(),
@@ -432,6 +408,10 @@ func (sdi *StateDiffIndexer) DetectGaps(beginBlockNumber uint64, endBlockNumber
 	return nil, nil
 }

+func (sdi *StateDiffIndexer) BeginTx(number *big.Int, _ context.Context) interfaces.Batch {
+	return NewBatch(number, sdi.dump)
+}
+
 // Close satisfies io.Closer
 func (sdi *StateDiffIndexer) Close() error {
 	return sdi.dump.Close()
@@ -16,14 +16,29 @@

 package file

+import "github.com/cerc-io/plugeth-statediff/utils/log"
+
 // BatchTx wraps a void with the state necessary for building the tx concurrently during trie difference iteration
 type BatchTx struct {
-	BlockNumber string
-
-	submit func(blockTx *BatchTx, err error) error
+	blockNum   string
+	fileWriter FileWriter
 }

 // Submit satisfies indexer.AtomicTx
-func (tx *BatchTx) Submit(err error) error {
-	return tx.submit(tx, err)
+func (tx *BatchTx) Submit() error {
+	tx.fileWriter.Flush()
+	return nil
+}
+
+func (tx *BatchTx) BlockNumber() string {
+	return tx.blockNum
+}
+
+func (tx *BatchTx) RollbackOnFailure(err error) {
+	if p := recover(); p != nil {
+		log.Info("panic detected before tx submission, but rollback not supported", "panic", p)
+		panic(p)
+	} else if err != nil {
+		log.Info("error detected before tx submission, but rollback not supported", "error", err)
+	}
 }
@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"strings"

-	"github.com/cerc-io/plugeth-statediff/indexer/node"
 	"github.com/cerc-io/plugeth-statediff/indexer/shared"
 )

@@ -30,7 +29,6 @@ type Config struct {
 	OutputDir                string
 	FilePath                 string
 	WatchedAddressesFilePath string
-	NodeInfo                 node.Info
 }

 // FileMode to explicitly type the mode of file writer we are using
@@ -70,20 +68,11 @@ func (c Config) Type() shared.DBType {
 	return shared.FILE
 }

-var nodeInfo = node.Info{
-	GenesisBlock: "0xd4e56740f876aef8c010b86a40d5f56745a118d0906a34e69aec8c0db1cb8fa3",
-	NetworkID:    "1",
-	ChainID:      1,
-	ID:           "mockNodeID",
-	ClientName:   "go-ethereum",
-}
-
 // CSVTestConfig config for unit tests
 var CSVTestConfig = Config{
 	Mode:                     CSV,
 	OutputDir:                "./statediffing_test",
 	WatchedAddressesFilePath: "./statediffing_watched_addresses_test_file.csv",
-	NodeInfo:                 nodeInfo,
 }

 // SQLTestConfig config for unit tests
@@ -91,5 +80,4 @@ var SQLTestConfig = Config{
 	Mode:                     SQL,
 	FilePath:                 "./statediffing_test_file.sql",
 	WatchedAddressesFilePath: "./statediffing_watched_addresses_test_file.sql",
-	NodeInfo:                 nodeInfo,
 }
@@ -43,7 +43,7 @@ func setupLegacyCSVIndexer(t *testing.T) {
 		require.NoError(t, err)
 	}

-	ind, err = file.NewStateDiffIndexer(test.LegacyConfig, file.CSVTestConfig)
+	ind, err = file.NewStateDiffIndexer(test.LegacyConfig, file.CSVTestConfig, test.LegacyNodeInfo)
 	require.NoError(t, err)

 	db, err = postgres.SetupSQLXDB()
@@ -41,7 +41,7 @@ func setupCSVIndexer(t *testing.T) {
 		require.NoError(t, err)
 	}

-	ind, err = file.NewStateDiffIndexer(mocks.TestChainConfig, file.CSVTestConfig)
+	ind, err = file.NewStateDiffIndexer(mocks.TestChainConfig, file.CSVTestConfig, test.LegacyNodeInfo)
 	require.NoError(t, err)

 	db, err = postgres.SetupSQLXDB()
@@ -17,6 +17,7 @@
 package file

 import (
+	"context"
 	"errors"
 	"fmt"
 	"math/big"
@@ -37,6 +38,7 @@ import (
 	"github.com/cerc-io/plugeth-statediff/indexer/interfaces"
 	"github.com/cerc-io/plugeth-statediff/indexer/ipld"
 	"github.com/cerc-io/plugeth-statediff/indexer/models"
+	"github.com/cerc-io/plugeth-statediff/indexer/node"
 	"github.com/cerc-io/plugeth-statediff/indexer/shared"
 	sdtypes "github.com/cerc-io/plugeth-statediff/types"
 	"github.com/cerc-io/plugeth-statediff/utils/log"
@@ -61,7 +63,7 @@ type StateDiffIndexer struct {
 }

 // NewStateDiffIndexer creates a void implementation of interfaces.StateDiffIndexer
-func NewStateDiffIndexer(chainConfig *params.ChainConfig, config Config) (*StateDiffIndexer, error) {
+func NewStateDiffIndexer(chainConfig *params.ChainConfig, config Config, nodeInfo node.Info) (*StateDiffIndexer, error) {
 	var err error
 	var writer FileWriter

@@ -114,12 +116,12 @@ func NewStateDiffIndexer(chainConfig *params.ChainConfig, config Config) (*State

 	wg := new(sync.WaitGroup)
 	writer.Loop()
-	writer.upsertNode(config.NodeInfo)
+	writer.upsertNode(nodeInfo)

 	return &StateDiffIndexer{
 		fileWriter:  writer,
 		chainConfig: chainConfig,
-		nodeID:      config.NodeInfo.ID,
+		nodeID:      nodeInfo.ID,
 		wg:          wg,
 	}, nil
 }
@@ -130,7 +132,7 @@ func (sdi *StateDiffIndexer) ReportDBMetrics(time.Duration, <-chan bool) {}
 // PushBlock pushes and indexes block data in sql, except state & storage nodes (includes header, uncles, transactions & receipts)
 // Returns an initiated DB transaction which must be Closed via defer to commit or rollback
 func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receipts, totalDifficulty *big.Int) (interfaces.Batch, error) {
-	start, t := time.Now(), time.Now()
+	t := time.Now()
 	blockHash := block.Hash()
 	blockHashStr := blockHash.String()
 	height := block.NumberU64()
@@ -142,7 +144,7 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	}

 	// Generate the block iplds
-	headerNode, txNodes, rctNodes, logNodes, err := ipld.FromBlockAndReceipts(block, receipts)
+	txNodes, rctNodes, logNodes, err := ipld.FromBlockAndReceipts(block, receipts)
 	if err != nil {
 		return nil, fmt.Errorf("error creating IPLD nodes from block and receipts: %v", err)
 	}
@@ -159,32 +161,19 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	} else {
 		reward = shared.CalcEthBlockReward(block.Header(), block.Uncles(), block.Transactions(), receipts)
 	}
-	t = time.Now()

 	blockTx := &BatchTx{
-		BlockNumber: block.Number().String(),
-		submit: func(self *BatchTx, err error) error {
-			tDiff := time.Since(t)
-			metrics.IndexerMetrics.StateStoreCodeProcessingTimer.Update(tDiff)
-			traceMsg += fmt.Sprintf("state, storage, and code storage processing time: %s\r\n", tDiff.String())
-			t = time.Now()
-			sdi.fileWriter.Flush()
-			tDiff = time.Since(t)
-			metrics.IndexerMetrics.PostgresCommitTimer.Update(tDiff)
-			traceMsg += fmt.Sprintf("postgres transaction commit duration: %s\r\n", tDiff.String())
-			traceMsg += fmt.Sprintf(" TOTAL PROCESSING DURATION: %s\r\n", time.Since(start).String())
-			log.Trace(traceMsg)
-			return err
-		},
+		blockNum:   block.Number().String(),
+		fileWriter: sdi.fileWriter,
 	}
-	tDiff := time.Since(t)
-	metrics.IndexerMetrics.FreePostgresTimer.Update(tDiff)
-	traceMsg += fmt.Sprintf("time spent waiting for free postgres tx: %s:\r\n", tDiff.String())
 	t = time.Now()

 	// write header, collect headerID
-	headerID := sdi.processHeader(block.Header(), headerNode, reward, totalDifficulty)
-	tDiff = time.Since(t)
+	headerID, err := sdi.PushHeader(blockTx, block.Header(), reward, totalDifficulty)
+	if err != nil {
+		return nil, err
+	}
+	tDiff := time.Since(t)
 	metrics.IndexerMetrics.HeaderProcessingTimer.Update(tDiff)
 	traceMsg += fmt.Sprintf("header processing time: %s\r\n", tDiff.String())
 	t = time.Now()
@@ -217,9 +206,14 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	return blockTx, err
 }

-// processHeader write a header IPLD insert SQL stmt to a file
+// PushHeader write a header IPLD insert SQL stmt to a file
 // it returns the headerID
-func (sdi *StateDiffIndexer) processHeader(header *types.Header, headerNode ipld.IPLD, reward, td *big.Int) string {
+func (sdi *StateDiffIndexer) PushHeader(_ interfaces.Batch, header *types.Header, reward, td *big.Int) (string, error) {
+	// Process the header
+	headerNode, err := ipld.NewEthHeader(header)
+	if err != nil {
+		return "", err
+	}
 	sdi.fileWriter.upsertIPLDNode(header.Number.String(), headerNode)

 	headerID := header.Hash().String()
@@ -240,7 +234,7 @@ func (sdi *StateDiffIndexer) processHeader(header *types.Header, headerNode ipld
 		Coinbase:        header.Coinbase.String(),
 		Canonical:       true,
 	})
-	return headerID
+	return headerID, nil
 }

 // processUncles publishes and indexes uncle IPLDs in Postgres
@@ -374,20 +368,16 @@ func (sdi *StateDiffIndexer) processReceiptsAndTxs(args processArgs) error {
 }

 // PushStateNode writes a state diff node object (including any child storage nodes) IPLD insert SQL stmt to a file
-func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdtypes.StateLeafNode, headerID string) error {
-	tx, ok := batch.(*BatchTx)
-	if !ok {
-		return fmt.Errorf("file: batch is expected to be of type %T, got %T", &BatchTx{}, batch)
-	}
+func (sdi *StateDiffIndexer) PushStateNode(tx interfaces.Batch, stateNode sdtypes.StateLeafNode, headerID string) error {
 	// publish the state node
 	var stateModel models.StateNodeModel
 	if stateNode.Removed {
 		if atomic.LoadUint32(&sdi.removedCacheFlag) == 0 {
 			atomic.StoreUint32(&sdi.removedCacheFlag, 1)
-			sdi.fileWriter.upsertIPLDDirect(tx.BlockNumber, shared.RemovedNodeStateCID, []byte{})
+			sdi.fileWriter.upsertIPLDDirect(tx.BlockNumber(), shared.RemovedNodeStateCID, []byte{})
 		}
 		stateModel = models.StateNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			CID:         shared.RemovedNodeStateCID,
@@ -395,7 +385,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 		}
 	} else {
 		stateModel = models.StateNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			CID:         stateNode.AccountWrapper.CID,
@@ -415,10 +405,10 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 		if storageNode.Removed {
 			if atomic.LoadUint32(&sdi.removedCacheFlag) == 0 {
 				atomic.StoreUint32(&sdi.removedCacheFlag, 1)
-				sdi.fileWriter.upsertIPLDDirect(tx.BlockNumber, shared.RemovedNodeStorageCID, []byte{})
+				sdi.fileWriter.upsertIPLDDirect(tx.BlockNumber(), shared.RemovedNodeStorageCID, []byte{})
 			}
 			storageModel := models.StorageNodeModel{
-				BlockNumber: tx.BlockNumber,
+				BlockNumber: tx.BlockNumber(),
 				HeaderID:    headerID,
 				StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 				StorageKey:  common.BytesToHash(storageNode.LeafKey).String(),
@@ -430,7 +420,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 			continue
 		}
 		storageModel := models.StorageNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			StorageKey:  common.BytesToHash(storageNode.LeafKey).String(),
@@ -445,12 +435,8 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 }

 // PushIPLD writes iplds to ipld.blocks
-func (sdi *StateDiffIndexer) PushIPLD(batch interfaces.Batch, ipld sdtypes.IPLD) error {
-	tx, ok := batch.(*BatchTx)
-	if !ok {
-		return fmt.Errorf("file: batch is expected to be of type %T, got %T", &BatchTx{}, batch)
-	}
-	sdi.fileWriter.upsertIPLDDirect(tx.BlockNumber, ipld.CID, ipld.Content)
+func (sdi *StateDiffIndexer) PushIPLD(tx interfaces.Batch, ipld sdtypes.IPLD) error {
+	sdi.fileWriter.upsertIPLDDirect(tx.BlockNumber(), ipld.CID, ipld.Content)
 	return nil
 }

@@ -472,6 +458,13 @@ func (sdi *StateDiffIndexer) HasBlock(hash common.Hash, number uint64) (bool, er
 	return false, nil
 }

+func (sdi *StateDiffIndexer) BeginTx(number *big.Int, _ context.Context) interfaces.Batch {
+	return &BatchTx{
+		blockNum:   number.String(),
+		fileWriter: sdi.fileWriter,
+	}
+}
+
 // Close satisfies io.Closer
 func (sdi *StateDiffIndexer) Close() error {
 	return sdi.fileWriter.Close()
@@ -83,7 +83,7 @@ func setupMainnetIndexer(t *testing.T) {
 		require.NoError(t, err)
 	}

-	ind, err = file.NewStateDiffIndexer(chainConf, file.CSVTestConfig)
+	ind, err = file.NewStateDiffIndexer(chainConf, file.CSVTestConfig, test.LegacyNodeInfo)
 	require.NoError(t, err)

 	db, err = postgres.SetupSQLXDB()
@@ -44,7 +44,7 @@ func setupLegacySQLIndexer(t *testing.T) {
 		require.NoError(t, err)
 	}

-	ind, err = file.NewStateDiffIndexer(test.LegacyConfig, file.SQLTestConfig)
+	ind, err = file.NewStateDiffIndexer(test.LegacyConfig, file.SQLTestConfig, test.LegacyNodeInfo)
 	require.NoError(t, err)

 	db, err = postgres.SetupSQLXDB()
@@ -41,7 +41,7 @@ func setupIndexer(t *testing.T) {
 		require.NoError(t, err)
 	}

-	ind, err = file.NewStateDiffIndexer(mocks.TestChainConfig, file.SQLTestConfig)
+	ind, err = file.NewStateDiffIndexer(mocks.TestChainConfig, file.SQLTestConfig, test.LegacyNodeInfo)
 	require.NoError(t, err)

 	db, err = postgres.SetupSQLXDB()
@@ -18,11 +18,14 @@ package sql

 import (
 	"context"
+	"math/big"
 	"sync"
 	"sync/atomic"
+	"time"

 	"github.com/lib/pq"

+	"github.com/cerc-io/plugeth-statediff/indexer/database/metrics"
 	"github.com/cerc-io/plugeth-statediff/indexer/ipld"
 	"github.com/cerc-io/plugeth-statediff/indexer/models"
 	"github.com/cerc-io/plugeth-statediff/utils/log"
@@ -32,7 +35,7 @@ const startingCacheCapacity = 1024 * 24

 // BatchTx wraps a sql tx with the state necessary for building the tx concurrently during trie difference iteration
 type BatchTx struct {
-	BlockNumber      string
+	blockNum         string
 	ctx              context.Context
 	dbtx             Tx
 	stm              string
@@ -42,13 +45,68 @@ type BatchTx struct {
 	removedCacheFlag *uint32
 	// Tracks expected cache size and ensures cache is caught up before flush
 	cacheWg sync.WaitGroup
-
-	submit func(blockTx *BatchTx, err error) error
 }

-// Submit satisfies indexer.AtomicTx
-func (tx *BatchTx) Submit(err error) error {
-	return tx.submit(tx, err)
+func NewBatch(insertStm string, ctx context.Context, number *big.Int, tx Tx) *BatchTx {
+	blockTx := &BatchTx{
+		removedCacheFlag: new(uint32),
+		ctx:              ctx,
+		blockNum:         number.String(),
+		stm:              insertStm,
+		iplds:            make(chan models.IPLDModel),
+		quit:             make(chan (chan<- struct{})),
+		ipldCache: models.IPLDBatch{
+			BlockNumbers: make([]string, 0, startingCacheCapacity),
+			Keys:         make([]string, 0, startingCacheCapacity),
+			Values:       make([][]byte, 0, startingCacheCapacity),
+		},
+		dbtx: tx,
+	}
+	go blockTx.cache()
+	return blockTx
+}
+
+// Submit satisfies indexer.Batch
+func (tx *BatchTx) Submit() error {
+	defer tx.close()
+
+	t := time.Now()
+	if err := tx.flush(); err != nil {
+		rollback(tx.ctx, tx.dbtx)
+		return err
+	}
+	err := tx.dbtx.Commit(tx.ctx)
+	metrics.IndexerMetrics.PostgresCommitTimer.Update(time.Since(t))
+	return err
+}
+
+func (tx *BatchTx) BlockNumber() string {
+	return tx.blockNum
+}
+
+func (tx *BatchTx) RollbackOnFailure(err error) {
+	if p := recover(); p != nil {
+		defer tx.close()
+		log.Info("panic detected before tx submission, rolling back the tx", "panic", p)
+		rollback(tx.ctx, tx.dbtx)
+		panic(p)
+	} else if err != nil {
+		defer tx.close()
+		log.Info("error detected before tx submission, rolling back the tx", "error", err)
+		rollback(tx.ctx, tx.dbtx)
+	}
+}
+
+func (tx *BatchTx) close() {
+	if tx.quit == nil {
+		return
+	}
+	confirm := make(chan struct{})
+	tx.quit <- confirm
+	close(tx.quit)
+	<-confirm
+	close(tx.iplds)
+	tx.quit = nil
 }

 func (tx *BatchTx) flush() error {
@@ -92,7 +150,7 @@ func (tx *BatchTx) cache() {
 func (tx *BatchTx) cacheDirect(key string, value []byte) {
 	tx.cacheWg.Add(1)
 	tx.iplds <- models.IPLDModel{
-		BlockNumber: tx.BlockNumber,
+		BlockNumber: tx.BlockNumber(),
 		Key:         key,
 		Data:        value,
 	}
@@ -101,7 +159,7 @@ func (tx *BatchTx) cacheDirect(key string, value []byte) {
 func (tx *BatchTx) cacheIPLD(i ipld.IPLD) {
 	tx.cacheWg.Add(1)
 	tx.iplds <- models.IPLDModel{
-		BlockNumber: tx.BlockNumber,
+		BlockNumber: tx.BlockNumber(),
 		Key:         i.Cid().String(),
 		Data:        i.RawData(),
 	}
@@ -112,7 +170,7 @@ func (tx *BatchTx) cacheRemoved(key string, value []byte) {
 		atomic.StoreUint32(tx.removedCacheFlag, 1)
 		tx.cacheWg.Add(1)
 		tx.iplds <- models.IPLDModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			Key:         key,
 			Data:        value,
 		}
@@ -39,7 +39,6 @@ import (
 	"github.com/cerc-io/plugeth-statediff/indexer/models"
 	"github.com/cerc-io/plugeth-statediff/indexer/shared"
 	sdtypes "github.com/cerc-io/plugeth-statediff/types"
-	"github.com/cerc-io/plugeth-statediff/utils/log"
 )

 var _ interfaces.StateDiffIndexer = &StateDiffIndexer{}
@@ -82,24 +81,26 @@ func (sdi *StateDiffIndexer) ReportDBMetrics(delay time.Duration, quit <-chan bo
 // PushBlock pushes and indexes block data in sql, except state & storage nodes (includes header, uncles, transactions & receipts)
 // Returns an initiated DB transaction which must be Closed via defer to commit or rollback
 func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receipts, totalDifficulty *big.Int) (interfaces.Batch, error) {
-	start, t := time.Now(), time.Now()
+	t := time.Now()
 	blockHash := block.Hash()
 	height := block.NumberU64()
-	traceMsg := fmt.Sprintf("indexer stats for statediff at %d with hash %s:\r\n", height, blockHash)
 	transactions := block.Transactions()
+	var err error
+
 	// Derive any missing fields
 	if err := receipts.DeriveFields(sdi.chainConfig, blockHash, height, block.BaseFee(), transactions); err != nil {
 		return nil, err
 	}

 	// Generate the block iplds
-	headerNode, txNodes, rctNodes, logNodes, err := ipld.FromBlockAndReceipts(block, receipts)
+	txNodes, rctNodes, logNodes, err := ipld.FromBlockAndReceipts(block, receipts)
 	if err != nil {
-		return nil, fmt.Errorf("error creating IPLD nodes from block and receipts: %v", err)
+		return nil, fmt.Errorf("error creating IPLD nodes from block and receipts: %w", err)
 	}

 	if len(txNodes) != len(rctNodes) {
-		return nil, fmt.Errorf("expected number of transactions (%d), receipts (%d)", len(txNodes), len(rctNodes))
+		return nil, fmt.Errorf("expected number of transactions (%d) does not match number of receipts (%d)",
+			len(txNodes), len(rctNodes))
 	}

 	// Calculate reward
@@ -108,99 +109,35 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	if sdi.chainConfig.Clique != nil {
 		reward = big.NewInt(0)
 	} else {
-		reward = shared.CalcEthBlockReward(block.Header(), block.Uncles(), block.Transactions(), receipts)
+		reward = shared.CalcEthBlockReward(block.Header(), block.Uncles(), transactions, receipts)
 	}
 	t = time.Now()

 	// Begin new DB tx for everything
-	tx := NewDelayedTx(sdi.dbWriter.db)
-	defer func() {
-		if p := recover(); p != nil {
-			rollback(sdi.ctx, tx)
-			panic(p)
-		} else if err != nil {
-			rollback(sdi.ctx, tx)
-		}
-	}()
-	blockTx := &BatchTx{
-		removedCacheFlag: new(uint32),
-		ctx:              sdi.ctx,
-		BlockNumber:      block.Number().String(),
-		stm:              sdi.dbWriter.db.InsertIPLDsStm(),
-		iplds:            make(chan models.IPLDModel),
-		quit:             make(chan (chan<- struct{})),
-		ipldCache: models.IPLDBatch{
-			BlockNumbers: make([]string, 0, startingCacheCapacity),
-			Keys:         make([]string, 0, startingCacheCapacity),
-			Values:       make([][]byte, 0, startingCacheCapacity),
-		},
-		dbtx: tx,
-		// handle transaction commit or rollback for any return case
-		submit: func(self *BatchTx, err error) error {
-			defer func() {
-				confirm := make(chan struct{})
-				self.quit <- confirm
-				close(self.quit)
-				<-confirm
-				close(self.iplds)
-			}()
-			if p := recover(); p != nil {
-				log.Info("panic detected before tx submission, rolling back the tx", "panic", p)
-				rollback(sdi.ctx, tx)
-				panic(p)
-			} else if err != nil {
-				log.Info("error detected before tx submission, rolling back the tx", "error", err)
-				rollback(sdi.ctx, tx)
-			} else {
-				tDiff := time.Since(t)
-				metrics2.IndexerMetrics.StateStoreCodeProcessingTimer.Update(tDiff)
-				traceMsg += fmt.Sprintf("state, storage, and code storage processing time: %s\r\n", tDiff)
-				t = time.Now()
-				if err := self.flush(); err != nil {
-					rollback(sdi.ctx, tx)
-					traceMsg += fmt.Sprintf(" TOTAL PROCESSING DURATION: %s\r\n", time.Since(start))
-					log.Debug(traceMsg)
-					return err
-				}
-				err = tx.Commit(sdi.ctx)
-				tDiff = time.Since(t)
-				metrics2.IndexerMetrics.PostgresCommitTimer.Update(tDiff)
-				traceMsg += fmt.Sprintf("postgres transaction commit duration: %s\r\n", tDiff)
-			}
-			traceMsg += fmt.Sprintf(" TOTAL PROCESSING DURATION: %s\r\n", time.Since(start))
-			log.Debug(traceMsg)
-			return err
-		},
-	}
-	go blockTx.cache()
-
-	tDiff := time.Since(t)
-	metrics2.IndexerMetrics.FreePostgresTimer.Update(tDiff)
-
-	traceMsg += fmt.Sprintf("time spent waiting for free postgres tx: %s:\r\n", tDiff)
-	t = time.Now()
+	batch := NewBatch(
+		sdi.dbWriter.db.InsertIPLDsStm(), sdi.ctx,
+		block.Number(),
+		NewDelayedTx(sdi.dbWriter.db),
+	)
+	// handle transaction rollback for failures in this scope
+	defer batch.RollbackOnFailure(err)

 	// Publish and index header, collect headerID
-	var headerID string
-	headerID, err = sdi.processHeader(blockTx, block.Header(), headerNode, reward, totalDifficulty)
+	headerID, err := sdi.PushHeader(batch, block.Header(), reward, totalDifficulty)
 	if err != nil {
 		return nil, err
 	}
-	tDiff = time.Since(t)
-	metrics2.IndexerMetrics.HeaderProcessingTimer.Update(tDiff)
-	traceMsg += fmt.Sprintf("header processing time: %s\r\n", tDiff)
+	metrics2.IndexerMetrics.HeaderProcessingTimer.Update(time.Since(t))
 	t = time.Now()
 	// Publish and index uncles
-	err = sdi.processUncles(blockTx, headerID, block.Number(), block.UncleHash(), block.Uncles())
+	err = sdi.processUncles(batch, headerID, block.Number(), block.UncleHash(), block.Uncles())
 	if err != nil {
 		return nil, err
 	}
-	tDiff = time.Since(t)
-	metrics2.IndexerMetrics.UncleProcessingTimer.Update(tDiff)
-	traceMsg += fmt.Sprintf("uncle processing time: %s\r\n", tDiff)
+	metrics2.IndexerMetrics.UncleProcessingTimer.Update(time.Since(t))
 	t = time.Now()
 	// Publish and index receipts and txs
-	err = sdi.processReceiptsAndTxs(blockTx, processArgs{
+	err = sdi.processReceiptsAndTxs(batch, processArgs{
 		headerID:    headerID,
 		blockNumber: block.Number(),
 		receipts:    receipts,
@@ -212,12 +149,9 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	if err != nil {
 		return nil, err
 	}
-	tDiff = time.Since(t)
-	metrics2.IndexerMetrics.TxAndRecProcessingTimer.Update(tDiff)
-	traceMsg += fmt.Sprintf("tx and receipt processing time: %s\r\n", tDiff)
-	t = time.Now()
+	metrics2.IndexerMetrics.TxAndRecProcessingTimer.Update(time.Since(t))

-	return blockTx, err
+	return batch, err
 }

 // CurrentBlock returns the HeaderModel of the highest existing block in the database.
@@ -230,9 +164,18 @@ func (sdi *StateDiffIndexer) DetectGaps(beginBlockNumber uint64, endBlockNumber
 	return sdi.dbWriter.detectGaps(beginBlockNumber, endBlockNumber)
 }

-// processHeader publishes and indexes a header IPLD in Postgres
+// PushHeader publishes and indexes a header IPLD in Postgres
 // it returns the headerID
-func (sdi *StateDiffIndexer) processHeader(tx *BatchTx, header *types.Header, headerNode ipld.IPLD, reward, td *big.Int) (string, error) {
+func (sdi *StateDiffIndexer) PushHeader(batch interfaces.Batch, header *types.Header, reward, td *big.Int) (string, error) {
+	tx, ok := batch.(*BatchTx)
+	if !ok {
+		return "", fmt.Errorf("sql: batch is expected to be of type %T, got %T", &BatchTx{}, batch)
+	}
+	// Process the header
+	headerNode, err := ipld.NewEthHeader(header)
+	if err != nil {
+		return "", err
+	}
 	tx.cacheIPLD(headerNode)

 	headerID := header.Hash().String()
@@ -406,7 +349,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 	if stateNode.Removed {
 		tx.cacheRemoved(shared.RemovedNodeStateCID, []byte{})
 		stateModel = models.StateNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			CID:         shared.RemovedNodeStateCID,
@@ -414,7 +357,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 		}
 	} else {
 		stateModel = models.StateNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			CID:         stateNode.AccountWrapper.CID,
@@ -436,7 +379,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 		if storageNode.Removed {
 			tx.cacheRemoved(shared.RemovedNodeStorageCID, []byte{})
 			storageModel := models.StorageNodeModel{
-				BlockNumber: tx.BlockNumber,
+				BlockNumber: tx.BlockNumber(),
 				HeaderID:    headerID,
 				StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 				StorageKey:  common.BytesToHash(storageNode.LeafKey).String(),
@@ -450,7 +393,7 @@ func (sdi *StateDiffIndexer) PushStateNode(batch interfaces.Batch, stateNode sdt
 			continue
 		}
 		storageModel := models.StorageNodeModel{
-			BlockNumber: tx.BlockNumber,
+			BlockNumber: tx.BlockNumber(),
 			HeaderID:    headerID,
 			StateKey:    common.BytesToHash(stateNode.AccountWrapper.LeafKey).String(),
 			StorageKey:  common.BytesToHash(storageNode.LeafKey).String(),
@@ -481,6 +424,15 @@ func (sdi *StateDiffIndexer) HasBlock(hash common.Hash, number uint64) (bool, er
 	return sdi.dbWriter.hasHeader(hash, number)
 }

+func (sdi *StateDiffIndexer) BeginTx(number *big.Int, ctx context.Context) interfaces.Batch {
+	return NewBatch(
+		sdi.dbWriter.db.InsertIPLDsStm(),
+		ctx,
+		number,
+		NewDelayedTx(sdi.dbWriter.db),
+	)
+}
+
 // Close satisfies io.Closer
 func (sdi *StateDiffIndexer) Close() error {
 	return sdi.dbWriter.Close()
@@ -3,7 +3,9 @@ package sql
 import (
 	"context"
 	"reflect"
+	"time"

+	"github.com/cerc-io/plugeth-statediff/indexer/database/metrics"
 	"github.com/cerc-io/plugeth-statediff/utils/log"
 )

@@ -69,10 +71,12 @@ func (tx *DelayedTx) Exec(ctx context.Context, sql string, args ...interface{})
 }

 func (tx *DelayedTx) Commit(ctx context.Context) error {
+	t := time.Now()
 	base, err := tx.db.Begin(ctx)
 	if err != nil {
 		return err
 	}
+	metrics.IndexerMetrics.FreePostgresTimer.Update(time.Since(t))
 	defer func() {
 		if p := recover(); p != nil {
 			rollback(ctx, base)
@@ -44,10 +44,6 @@ type Config struct {
 	ConnTimeout     time.Duration
 	LogStatements   bool

-	// node info params
-	ID         string
-	ClientName string
-
 	// driver type
 	Driver DriverType

@@ -17,6 +17,7 @@
 package interfaces

 import (
+	"context"
 	"math/big"
 	"time"

@@ -34,10 +35,13 @@ type StateDiffIndexer interface {
 	CurrentBlock() (*models.HeaderModel, error)
 	HasBlock(hash common.Hash, number uint64) (bool, error)
 	PushBlock(block *types.Block, receipts types.Receipts, totalDifficulty *big.Int) (Batch, error)
+	PushHeader(batch Batch, header *types.Header, reward, td *big.Int) (string, error)
 	PushStateNode(tx Batch, stateNode sdtypes.StateLeafNode, headerID string) error
 	PushIPLD(tx Batch, ipld sdtypes.IPLD) error
 	ReportDBMetrics(delay time.Duration, quit <-chan bool)

+	BeginTx(number *big.Int, ctx context.Context) Batch
+
 	// Methods used by WatchAddress API/functionality
 	LoadWatchedAddresses() ([]common.Address, error)
 	InsertWatchedAddresses(addresses []sdtypes.WatchAddressArg, currentBlock *big.Int) error
@@ -50,7 +54,12 @@ type StateDiffIndexer interface {

 // Batch required for indexing data atomically
 type Batch interface {
-	Submit(err error) error
+	// Submit commits the batch transaction
+	Submit() error
+	// BlockNumber is the block number of the header this batch contains
+	BlockNumber() string
+	// RollbackOnFailure rolls back the batch transaction if the error is not nil
+	RollbackOnFailure(error)
 }

 // Config used to configure different underlying implementations
@@ -22,23 +22,17 @@ import (

 // FromBlockAndReceipts takes a block and processes it
 // to return it a set of IPLD nodes for further processing.
-func FromBlockAndReceipts(block *types.Block, receipts []*types.Receipt) (*EthHeader, []*EthTx, []*EthReceipt, [][]*EthLog, error) {
-	// Process the header
-	headerNode, err := NewEthHeader(block.Header())
-	if err != nil {
-		return nil, nil, nil, nil, err
-	}
-
+func FromBlockAndReceipts(block *types.Block, receipts []*types.Receipt) ([]*EthTx, []*EthReceipt, [][]*EthLog, error) {
 	// Process the txs
 	txNodes, err := processTransactions(block.Transactions())
 	if err != nil {
-		return nil, nil, nil, nil, err
+		return nil, nil, nil, err
 	}

 	// Process the receipts and logs
 	rctNodes, logNodes, err := processReceiptsAndLogs(receipts)

-	return headerNode, txNodes, rctNodes, logNodes, err
+	return txNodes, rctNodes, logNodes, err
 }

 // processTransactions will take the found transactions in a parsed block body
@@ -92,7 +92,7 @@ func loadBlockData(t *testing.T) []testCase {
 func TestFromBlockAndReceipts(t *testing.T) {
 	testCases := loadBlockData(t)
 	for _, tc := range testCases {
-		_, _, _, _, err := FromBlockAndReceipts(tc.block, tc.receipts)
+		_, _, _, err := FromBlockAndReceipts(tc.block, tc.receipts)
 		if err != nil {
 			t.Fatalf("error generating IPLDs from block and receipts, err %v, kind %s, block hash %s", err, tc.kind, tc.block.Hash())
 		}
@@ -0,0 +1,7 @@
+package indexer
+
+import "github.com/cerc-io/plugeth-statediff/indexer/interfaces"
+
+type Indexer = interfaces.StateDiffIndexer
+type Batch = interfaces.Batch
+type Config = interfaces.Config
@@ -43,7 +43,8 @@ var testHeaderTable = Table{
 		"mh_key",
 		"times_validated",
 		"coinbase",
-	)}
+	),
+}

 func TestTable(t *testing.T) {
 	headerUpsert := `INSERT INTO eth.header_cids (block_number, block_hash, parent_hash, cid, td, node_id, reward, state_root, tx_root, receipt_root, uncle_root, bloom, timestamp, mh_key, times_validated, coinbase) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16) ON CONFLICT (block_hash, block_number) DO UPDATE SET (parent_hash, cid, td, node_id, reward, state_root, tx_root, receipt_root, uncle_root, bloom, timestamp, mh_key, times_validated, coinbase) = ($3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16)`
@@ -28,7 +28,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"

-	"github.com/cerc-io/plugeth-statediff/indexer/database/file"
 	"github.com/cerc-io/plugeth-statediff/indexer/database/sql"
 	"github.com/cerc-io/plugeth-statediff/indexer/interfaces"
 	"github.com/cerc-io/plugeth-statediff/indexer/mocks"
@@ -48,7 +47,7 @@ func SetupTestData(t *testing.T, ind interfaces.StateDiffIndexer) {
 		t.Fatal(err)
 	}
 	defer func() {
-		if err := tx.Submit(err); err != nil {
+		if err := tx.Submit(); err != nil {
 			t.Fatal(err)
 		}
 	}()
@@ -61,11 +60,7 @@ func SetupTestData(t *testing.T, ind interfaces.StateDiffIndexer) {
 		require.NoError(t, err)
 	}

-	if batchTx, ok := tx.(*sql.BatchTx); ok {
-		require.Equal(t, mocks.BlockNumber.String(), batchTx.BlockNumber)
-	} else if batchTx, ok := tx.(*file.BatchTx); ok {
-		require.Equal(t, mocks.BlockNumber.String(), batchTx.BlockNumber)
-	}
+	require.Equal(t, mocks.BlockNumber.String(), tx.BlockNumber())
 }

 func DoTestPublishAndIndexHeaderIPLDs(t *testing.T, db sql.Database) {
@@ -547,13 +542,9 @@ func SetupTestDataNonCanonical(t *testing.T, ind interfaces.StateDiffIndexer) {
 		require.NoError(t, err)
 	}

-	if batchTx, ok := tx1.(*sql.BatchTx); ok {
-		require.Equal(t, mocks.BlockNumber.String(), batchTx.BlockNumber)
-	} else if batchTx, ok := tx1.(*file.BatchTx); ok {
-		require.Equal(t, mocks.BlockNumber.String(), batchTx.BlockNumber)
-	}
+	require.Equal(t, mocks.BlockNumber.String(), tx1.BlockNumber())

-	if err := tx1.Submit(err); err != nil {
+	if err := tx1.Submit(); err != nil {
 		t.Fatal(err)
 	}

@@ -572,13 +563,9 @@ func SetupTestDataNonCanonical(t *testing.T, ind interfaces.StateDiffIndexer) {
 		require.NoError(t, err)
 	}

-	if tx, ok := tx2.(*sql.BatchTx); ok {
-		require.Equal(t, mocks.BlockNumber.String(), tx.BlockNumber)
-	} else if tx, ok := tx2.(*sql.BatchTx); ok {
-		require.Equal(t, mocks.BlockNumber.String(), tx.BlockNumber)
-	}
+	require.Equal(t, mocks.BlockNumber.String(), tx2.BlockNumber())

-	if err := tx2.Submit(err); err != nil {
+	if err := tx2.Submit(); err != nil {
 		t.Fatal(err)
 	}

@@ -597,13 +584,9 @@ func SetupTestDataNonCanonical(t *testing.T, ind interfaces.StateDiffIndexer) {
 		require.NoError(t, err)
 	}

-	if batchTx, ok := tx3.(*sql.BatchTx); ok {
-		require.Equal(t, mocks.Block2Number.String(), batchTx.BlockNumber)
-	} else if batchTx, ok := tx3.(*file.BatchTx); ok {
-		require.Equal(t, mocks.Block2Number.String(), batchTx.BlockNumber)
-	}
+	require.Equal(t, mocks.Block2Number.String(), tx3.BlockNumber())

-	if err := tx3.Submit(err); err != nil {
+	if err := tx3.Submit(); err != nil {
 		t.Fatal(err)
 	}
 }
@@ -20,11 +20,11 @@ import (
 	"context"
 	"testing"

-	"github.com/cerc-io/plugeth-statediff/indexer/database/file"
 	"github.com/cerc-io/plugeth-statediff/indexer/database/sql"
 	"github.com/cerc-io/plugeth-statediff/indexer/interfaces"
 	"github.com/cerc-io/plugeth-statediff/indexer/ipld"
 	"github.com/cerc-io/plugeth-statediff/indexer/mocks"
+	"github.com/cerc-io/plugeth-statediff/indexer/node"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ipfs/go-cid"
@@ -37,6 +37,14 @@ var (
 	legacyData      = mocks.NewLegacyData(LegacyConfig)
 	mockLegacyBlock *types.Block
 	legacyHeaderCID cid.Cid
+	// Mainnet node info
+	LegacyNodeInfo = node.Info{
+		GenesisBlock: "0xd4e56740f876aef8c010b86a40d5f56745a118d0906a34e69aec8c0db1cb8fa3",
+		NetworkID:    "1",
+		ChainID:      1,
+		ID:           "mockNodeID",
+		ClientName:   "go-ethereum",
+	}
 )

 func SetupLegacyTestData(t *testing.T, ind interfaces.StateDiffIndexer) {
@@ -51,7 +59,7 @@ func SetupLegacyTestData(t *testing.T, ind interfaces.StateDiffIndexer) {
 	require.NoError(t, err)

 	defer func() {
-		if err := tx.Submit(err); err != nil {
+		if err := tx.Submit(); err != nil {
 			t.Fatal(err)
 		}
 	}()
@@ -60,11 +68,7 @@ func SetupLegacyTestData(t *testing.T, ind interfaces.StateDiffIndexer) {
 		require.NoError(t, err)
 	}

-	if batchTx, ok := tx.(*sql.BatchTx); ok {
-		require.Equal(t, legacyData.BlockNumber.String(), batchTx.BlockNumber)
-	} else if batchTx, ok := tx.(*file.BatchTx); ok {
-		require.Equal(t, legacyData.BlockNumber.String(), batchTx.BlockNumber)
-	}
+	require.Equal(t, legacyData.BlockNumber.String(), tx.BlockNumber())
 }

 func TestLegacyIndexer(t *testing.T, db sql.Database) {
@@ -19,8 +19,6 @@ package test
 import (
 	"testing"

-	"github.com/cerc-io/plugeth-statediff/indexer/database/file"
-	"github.com/cerc-io/plugeth-statediff/indexer/database/sql"
 	"github.com/cerc-io/plugeth-statediff/indexer/interfaces"
 	"github.com/cerc-io/plugeth-statediff/indexer/mocks"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -36,7 +34,7 @@ func TestBlock(t *testing.T, ind interfaces.StateDiffIndexer, testBlock *types.B
 	require.NoError(t, err)

 	defer func() {
-		if err := tx.Submit(err); err != nil {
+		if err := tx.Submit(); err != nil {
 			t.Fatal(err)
 		}
 	}()
@@ -45,9 +43,5 @@ func TestBlock(t *testing.T, ind interfaces.StateDiffIndexer, testBlock *types.B
 		require.NoError(t, err)
 	}

-	if batchTx, ok := tx.(*sql.BatchTx); ok {
-		require.Equal(t, testBlock.Number().String(), batchTx.BlockNumber)
-	} else if batchTx, ok := tx.(*file.BatchTx); ok {
-		require.Equal(t, testBlock.Number().String(), batchTx.BlockNumber)
-	}
+	require.Equal(t, testBlock.Number().String(), tx.BlockNumber())
 }
@@ -173,8 +173,6 @@ func initConfig() {
 	case shared.FILE:
 		indexerConfig = fileConfig
 	case shared.POSTGRES:
-		dbConfig.ID = config.ID
-		dbConfig.ClientName = config.ClientName
 		indexerConfig = dbConfig
 	case shared.DUMP:
 		switch dbDumpDst {
@@ -47,8 +47,12 @@ func InitializeNode(stack core.Node, b core.Backend) {
 			ClientName:   serviceConfig.ClientName,
 		}
 		var err error
-		_, indexer, err = ind.NewStateDiffIndexer(serviceConfig.Context,
-			adapt.ChainConfig(backend.ChainConfig()), info, serviceConfig.IndexerConfig)
+		_, indexer, err = ind.NewStateDiffIndexer(
+			serviceConfig.Context,
+			adapt.ChainConfig(backend.ChainConfig()),
+			info,
+			serviceConfig.IndexerConfig,
+		)
 		if err != nil {
 			log.Error("failed to construct indexer", "error", err)
 		}
@@ -444,7 +444,7 @@ func TestBuilderOnMainnetBlocks(t *testing.T) {
 	}
 	params := statediff.Params{}

-	var tests = []test_helpers.TestCase{
+	var tests = []test_helpers.DiffTestCase{
 		// note that block0 (genesis) has over 1000 nodes due to the pre-allocation for the crowd-sale
 		// it is not feasible to write a unit test of that size at this time
 		{
@@ -624,7 +624,7 @@ func TestBuilderOnMainnetBlocks(t *testing.T) {
 		},
 	}

-	test_helpers.RunBuilderTests(t, chain.StateCache(), tests, params, []uint{1, 8, 32})
+	test_helpers.RunBuildStateDiff(t, chain.StateCache(), tests, params)
 	test_helpers.CheckedRoots{
 		block1: block1RootBranchNode,
 		block2: block2RootBranchNode,
@@ -817,11 +817,15 @@ func (sds *Service) writeStateDiff(block *types.Block, parentRoot common.Hash, p
 	if params.IncludeReceipts {
 		receipts = sds.BlockChain.GetReceiptsByHash(block.Hash())
 	}
+
+	t := time.Now()
 	tx, err = sds.indexer.PushBlock(block, receipts, totalDifficulty)
 	if err != nil {
 		return err
 	}
+	defer tx.RollbackOnFailure(err)

+	// TODO: review/remove the need to sync here
 	var nodeMtx, ipldMtx sync.Mutex
 	nodeSink := func(node types2.StateLeafNode) error {
 		defer metrics.UpdateDuration(time.Now(), metrics.IndexerMetrics.OutputTimer)
@@ -842,9 +846,12 @@ func (sds *Service) writeStateDiff(block *types.Block, parentRoot common.Hash, p
 		BlockHash:    block.Hash(),
 		BlockNumber:  block.Number(),
 	}, params, nodeSink, ipldSink)
+	if err != nil {
+		return err
+	}

-	// TODO this anti-pattern needs to be sorted out eventually
-	if err = tx.Submit(err); err != nil {
+	metrics.IndexerMetrics.StateStoreCodeProcessingTimer.Update(time.Since(t))
+	if err = tx.Submit(); err != nil {
 		return fmt.Errorf("batch transaction submission failed: %w", err)
 	}
 	return nil
@@ -4,9 +4,13 @@ import (
 	"bytes"
 	"fmt"
 	"math/big"
+	"math/rand"
+	"path/filepath"
 	"sort"
+	"sync"
 	"testing"

+	"github.com/cerc-io/eth-iterator-utils/tracker"
 	statediff "github.com/cerc-io/plugeth-statediff"
 	"github.com/cerc-io/plugeth-statediff/adapt"
 	sdtypes "github.com/cerc-io/plugeth-statediff/types"
@@ -17,12 +21,20 @@ import (
 	"github.com/stretchr/testify/require"
 )

-type TestCase struct {
+var subtrieCounts = []uint{1, 8, 32}
+
+type DiffTestCase struct {
 	Name     string
 	Args     statediff.Args
 	Expected *sdtypes.StateObject
 }

+type SnapshotTestCase struct {
+	Name      string
+	StateRoot common.Hash
+	Expected  *sdtypes.StateObject
+}
+
 type CheckedRoots map[*types.Block][]byte

 // Replicates the statediff object, but indexes nodes by CID
@@ -33,12 +45,11 @@ type normalizedStateDiff struct {
 	IPLDs       map[string]sdtypes.IPLD
 }

-func RunBuilderTests(
+func RunBuildStateDiff(
 	t *testing.T,
 	sdb state.Database,
-	tests []TestCase,
+	tests []DiffTestCase,
 	params statediff.Params,
-	subtrieCounts []uint,
 ) {
 	builder := statediff.NewBuilder(adapt.GethStateView(sdb))
 	for _, test := range tests {
@@ -58,6 +69,79 @@ func RunBuilderTests(
 	}
 }

+func RunStateSnapshot(
+	t *testing.T,
+	sdb state.Database,
+	test SnapshotTestCase,
+	params statediff.Params,
+) {
+	builder := statediff.NewBuilder(adapt.GethStateView(sdb))
+
+	for _, subtries := range subtrieCounts {
+		// Skip the recovery test for empty diffs
+		doRecovery := len(test.Expected.Nodes) != 0
+
+		t.Run(fmt.Sprintf("%s with %d subtries", test.Name, subtries), func(t *testing.T) {
+			builder.SetSubtrieWorkers(subtries)
+			var stateNodes []sdtypes.StateLeafNode
+			var iplds []sdtypes.IPLD
+			interrupt := randomInterrupt(len(test.Expected.IPLDs))
+			stateAppender := failingSyncedAppender(&stateNodes, -1)
+			ipldAppender := failingSyncedAppender(&iplds, interrupt)
+			recoveryFile := filepath.Join(t.TempDir(), "recovery.txt")
+			build := func() error {
+				tr := tracker.New(recoveryFile, subtries)
+				defer tr.CloseAndSave()
+				return builder.WriteStateSnapshot(
+					test.StateRoot, params, stateAppender, ipldAppender, tr,
+				)
+			}
+			if doRecovery {
+				// First attempt fails, second succeeds
+				if build() == nil {
+					t.Fatal("expected an error")
+				}
+				require.FileExists(t, recoveryFile)
+			}
+			ipldAppender = failingSyncedAppender(&iplds, -1)
+			if err := build(); err != nil {
+				t.Fatal(err)
+			}
+			diff := sdtypes.StateObject{
+				Nodes: stateNodes,
+				IPLDs: iplds,
+			}
+			require.Equal(t,
+				normalize(test.Expected),
+				normalize(&diff),
+			)
+		})
+	}
+
+}
+
+// an appender which fails on a configured trigger
+func failingSyncedAppender[T any](to *[]T, failAt int) func(T) error {
+	var mtx sync.Mutex
+	return func(item T) error {
+		mtx.Lock()
+		defer mtx.Unlock()
+		if len(*to) == failAt {
+			return fmt.Errorf("failing at %d items", failAt)
+		}
+		*to = append(*to, item)
+		return nil
+	}
+}
+
+// function to pick random int between N/4 and 3N/4
+func randomInterrupt(N int) int {
+	if N < 2 {
+		return 0
+	}
+	return rand.Intn(N/2) + N/4
+}
+
 func (roots CheckedRoots) Check(t *testing.T) {
 	// Let's also confirm that our root state nodes form the state root hash in the headers
 	for block, node := range roots {
@@ -17,6 +17,7 @@
 package mocks

 import (
+	context "context"
 	"math/big"
 	"time"

@@ -52,6 +53,10 @@ func (sdi *StateDiffIndexer) PushBlock(block *types.Block, receipts types.Receip
 	return &batch{}, nil
 }

+func (sdi *StateDiffIndexer) PushHeader(batch interfaces.Batch, header *types.Header, reward, td *big.Int) (string, error) {
+	return "", nil
+}
+
 func (sdi *StateDiffIndexer) PushStateNode(txi interfaces.Batch, stateNode sdtypes.StateLeafNode, headerID string) error {
 	return nil
 }
@@ -80,10 +85,21 @@ func (sdi *StateDiffIndexer) ClearWatchedAddresses() error {
 	return nil
 }

+func (sdi *StateDiffIndexer) BeginTx(number *big.Int, ctx context.Context) interfaces.Batch {
+	return &batch{}
+}
+
 func (sdi *StateDiffIndexer) Close() error {
 	return nil
 }

-func (tx *batch) Submit(err error) error {
+func (tx *batch) RollbackOnFailure(error) {}
+
+func (tx *batch) Submit() error {
 	return nil
 }
+
+// batch.BlockNumber
+func (tx *batch) BlockNumber() string {
+	return "0"
+}
@@ -53,7 +53,7 @@ type StateLeafNode struct {
 	StorageDiff    []StorageLeafNode
 }

-// StorageLeafNode holds the data for a single storage diff node leaf node
+// StorageLeafNode holds the data for a single storage diff leaf node
 type StorageLeafNode struct {
 	Removed bool
 	Value   []byte
@@ -7,24 +7,9 @@ import (
 	"github.com/ethereum/go-ethereum/trie"
 )

-type symmDiffIterator struct {
-	a, b        iterState // Nodes returned are those in b - a and a - b (keys only)
-	yieldFromA  bool      // Whether next node comes from a
-	count       int       // Number of nodes scanned on either trie
-	eqPathIndex int       // Count index of last pair of equal paths, to detect an updated key
-}
-
-// NewSymmetricDifferenceIterator constructs a trie.NodeIterator that iterates over the symmetric difference
-// of elements in a and b, i.e., the elements in a that are not in b, and vice versa.
-// Returns the iterator, and a pointer to an integer recording the number of nodes seen.
-func NewSymmetricDifferenceIterator(a, b trie.NodeIterator) (*symmDiffIterator, *int) {
-	it := &symmDiffIterator{
-		a: iterState{a, true},
-		b: iterState{b, true},
-		// common paths are detected by a distance <=1 from this index, so put it out of reach
-		eqPathIndex: -2,
-	}
-	return it, &it.count
+type SymmDiffIterator struct {
+	a, b iterState // Nodes returned are those in b - a and a - b (keys only)
+	SymmDiffState
 }

 // pairs an iterator with a cache of its valid status
@@ -33,66 +18,93 @@ type iterState struct {
 	valid bool
 }

+// SymmDiffState exposes state specific to symmetric difference iteration, which is not accessible
+// from the NodeIterator interface. This includes the number of nodes seen, whether the current key
+// is common to both A and B, and whether the current node is sourced from A or B.
+type SymmDiffState struct {
+	yieldFromA  bool // Whether next node comes from a
+	count       int  // Number of nodes scanned on either trie
+	eqPathIndex int  // Count index of last pair of equal paths, to detect an updated key
+}
+
+// NewSymmetricDifferenceIterator constructs a trie.NodeIterator that iterates over the symmetric difference
+// of elements in a and b, i.e., the elements in a that are not in b, and vice versa.
+// Returns the iterator, and a pointer to an auxiliary object for accessing the state not exposed by the NodeIterator interface recording the number of nodes seen.
+func NewSymmetricDifferenceIterator(a, b trie.NodeIterator) *SymmDiffIterator {
+	it := &SymmDiffIterator{
+		a: iterState{a, true},
+		b: iterState{b, true},
+		// common paths are detected by a distance <=1 between count and this index, so we start at -2
+		SymmDiffState: SymmDiffState{eqPathIndex: -2},
+	}
+	return it
+}
+
 func (st *iterState) Next(descend bool) bool {
 	st.valid = st.NodeIterator.Next(descend)
 	return st.valid
 }

-func (it *symmDiffIterator) curr() *iterState {
+// FromA returns true if the current node is sourced from A.
+func (it *SymmDiffState) FromA() bool {
+	return it.yieldFromA
+}
+
+// CommonPath returns true if a node with the current path exists in each sub-iterator - i.e. it
+// represents an updated node.
+func (it *SymmDiffState) CommonPath() bool {
+	return it.count-it.eqPathIndex <= 1
+}
+
+// Count returns the number of nodes seen.
+func (it *SymmDiffState) Count() int {
+	return it.count
+}
+
+func (it *SymmDiffIterator) curr() *iterState {
 	if it.yieldFromA {
 		return &it.a
 	}
 	return &it.b
 }

-// FromA returns true if the current node is sourced from A.
-func (it *symmDiffIterator) FromA() bool {
-	return it.yieldFromA
-}
-
-// CommonPath returns true if a node with the current path exists in each sub-iterator - i.e. it
-// represents an updated node.
-func (it *symmDiffIterator) CommonPath() bool {
-	return it.count-it.eqPathIndex <= 1
-}
-
-func (it *symmDiffIterator) Hash() common.Hash {
+func (it *SymmDiffIterator) Hash() common.Hash {
 	return it.curr().Hash()
 }

-func (it *symmDiffIterator) Parent() common.Hash {
+func (it *SymmDiffIterator) Parent() common.Hash {
 	return it.curr().Parent()
 }

-func (it *symmDiffIterator) Leaf() bool {
+func (it *SymmDiffIterator) Leaf() bool {
 	return it.curr().Leaf()
 }

-func (it *symmDiffIterator) LeafKey() []byte {
+func (it *SymmDiffIterator) LeafKey() []byte {
 	return it.curr().LeafKey()
 }

-func (it *symmDiffIterator) LeafBlob() []byte {
+func (it *SymmDiffIterator) LeafBlob() []byte {
 	return it.curr().LeafBlob()
 }

-func (it *symmDiffIterator) LeafProof() [][]byte {
+func (it *SymmDiffIterator) LeafProof() [][]byte {
 	return it.curr().LeafProof()
 }

-func (it *symmDiffIterator) Path() []byte {
+func (it *SymmDiffIterator) Path() []byte {
 	return it.curr().Path()
 }

-func (it *symmDiffIterator) NodeBlob() []byte {
+func (it *SymmDiffIterator) NodeBlob() []byte {
 	return it.curr().NodeBlob()
 }

-func (it *symmDiffIterator) AddResolver(resolver trie.NodeResolver) {
+func (it *SymmDiffIterator) AddResolver(resolver trie.NodeResolver) {
 	panic("not implemented")
 }

-func (it *symmDiffIterator) Next(bool) bool {
+func (it *SymmDiffIterator) Next(bool) bool {
 	// NodeIterators start in a "pre-valid" state, so the first Next advances to a valid node.
 	if it.count == 0 {
 		if it.a.Next(true) {
@@ -110,7 +122,7 @@ func (it *symmDiffIterator) Next(bool) bool {
 	return it.a.valid || it.b.valid
 }

-func (it *symmDiffIterator) seek() {
+func (it *SymmDiffIterator) seek() {
 	// Invariants:
 	// - At the end of the function, the sub-iterator with the lexically lesser path
 	// points to the next element
@@ -151,7 +163,7 @@ func (it *symmDiffIterator) seek() {
 	}
 }

-func (it *symmDiffIterator) Error() error {
+func (it *SymmDiffIterator) Error() error {
 	if err := it.a.Error(); err != nil {
 		return err
 	}
@@ -172,3 +184,9 @@ func compareNodes(a, b trie.NodeIterator) int {
 	}
 	return 0
 }
+
+// AlwaysBState returns a dummy SymmDiffState that indicates all elements are from B, and have no
+// common paths with A. This is equivalent to a diff against an empty A.
+func AlwaysBState() SymmDiffState {
+	return SymmDiffState{yieldFromA: false, eqPathIndex: -2}
+}
@@ -45,37 +45,33 @@ func TestSymmetricDifferenceIterator(t *testing.T) {
 	t.Run("with no difference", func(t *testing.T) {
 		db := trie.NewDatabase(rawdb.NewMemoryDatabase())
 		triea := trie.NewEmpty(db)
-		di, count := utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), triea.NodeIterator(nil))
+		di := utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), triea.NodeIterator(nil))
 		for di.Next(true) {
 			t.Errorf("iterator should not yield any elements")
 		}
-		assert.Equal(t, 0, *count)
+		assert.Equal(t, 0, di.Count())

 		triea.MustUpdate([]byte("foo"), []byte("bar"))
-		di, count = utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), triea.NodeIterator(nil))
+		di = utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), triea.NodeIterator(nil))
 		for di.Next(true) {
 			t.Errorf("iterator should not yield any elements")
 		}
-		assert.Equal(t, 2, *count)
+		// two nodes visited: the leaf (value) and its parent
+		assert.Equal(t, 2, di.Count())

-		// TODO will fail until fixed https://github.com/ethereum/go-ethereum/pull/27838
 		trieb := trie.NewEmpty(db)
-		di, count = utils.NewSymmetricDifferenceIterator(
-			triea.NodeIterator([]byte("jars")),
-			trieb.NodeIterator(nil))
+		di = utils.NewSymmetricDifferenceIterator(triea.NodeIterator([]byte("jars")), trieb.NodeIterator(nil))
 		for di.Next(true) {
-			t.Errorf("iterator should not yield any elements, but got key %s", di.Path())
+			t.Errorf("iterator should not yield any elements")
 		}
-		assert.Equal(t, 0, *count)
+		assert.Equal(t, 0, di.Count())

-		// // TODO will fail until merged: https://github.com/ethereum/go-ethereum/pull/27838
-		// di, count = utils.NewSymmetricDifferenceIterator(
-		// 	triea.NodeIterator([]byte("food")),
-		// 	trieb.NodeIterator(nil))
+		// TODO will fail until merged: https://github.com/ethereum/go-ethereum/pull/27838
+		// di, aux = utils.NewSymmetricDifferenceIterator(triea.NodeIterator([]byte("food")), trieb.NodeIterator(nil))
 		// for di.Next(true) {
-		// 	t.Errorf("iterator should not yield any elements, but got key %s", di.Path())
+		// 	t.Errorf("iterator should not yield any elements")
 		// }
-		// assert.Equal(t, 0, *count)
+		// assert.Equal(t, 0, di.Count())
 	})

 	t.Run("small difference", func(t *testing.T) {
@@ -86,7 +82,7 @@ func TestSymmetricDifferenceIterator(t *testing.T) {
 		trieb := trie.NewEmpty(dbb)
 		trieb.MustUpdate([]byte("foo"), []byte("bar"))

-		di, count := utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator(nil))
+		di := utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator(nil))
 		leaves := 0
 		for di.Next(true) {
 			if di.Leaf() {
@@ -97,10 +93,10 @@ func TestSymmetricDifferenceIterator(t *testing.T) {
 			}
 		}
 		assert.Equal(t, 1, leaves)
-		assert.Equal(t, 2, *count)
+		assert.Equal(t, 2, di.Count())

 		trieb.MustUpdate([]byte("quux"), []byte("bars"))
-		di, count = utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator([]byte("quux")))
+		di = utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator([]byte("quux")))
 		leaves = 0
 		for di.Next(true) {
 			if di.Leaf() {
@@ -111,7 +107,7 @@ func TestSymmetricDifferenceIterator(t *testing.T) {
 			}
 		}
 		assert.Equal(t, 1, leaves)
-		assert.Equal(t, 1, *count)
+		assert.Equal(t, 1, di.Count())
 	})

 	dba := trie.NewDatabase(rawdb.NewMemoryDatabase())
@@ -128,7 +124,7 @@ func TestSymmetricDifferenceIterator(t *testing.T) {
 	onlyA := make(map[string]string)
 	onlyB := make(map[string]string)
 	var deletions, creations []string
-	it, _ := utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator(nil))
+	it := utils.NewSymmetricDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator(nil))
 	for it.Next(true) {
 		if !it.Leaf() {
 			continue
@@ -209,7 +205,7 @@ func TestCompareDifferenceIterators(t *testing.T) {
 		pathsA = append(pathsA, itAonly.Path())
 	}

-	itSym, _ := utils.NewSymmetricDifferenceIterator(treeA.NodeIterator(nil), treeB.NodeIterator(nil))
+	itSym := utils.NewSymmetricDifferenceIterator(treeA.NodeIterator(nil), treeB.NodeIterator(nil))
 	var idxA, idxB int
 	for itSym.Next(true) {
 		if itSym.FromA() {
@@ -17,6 +17,7 @@ func init() {
 	// The plugeth logger is only initialized with the geth runtime,
 	// but tests expect to have a logger available, so default to this.
 	DefaultLogger = TestLogger
+	TestLogger.SetLevel(int(log15.LvlInfo))
 }

 func Trace(m string, a ...interface{}) { DefaultLogger.Trace(m, a...) }