build success

23 files changed, 777 insertions, 2495 deletions

diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index d239aca..b27525b 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -566,7 +566,7 @@ func (c *Clique) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *
 	header.UncleHash = types.CalcUncleHash(nil)
 
 	// Assemble and return the final block for sealing
-	return types.NewBlock(header, txs, nil, receipts, new(trie.Trie)), nil
+	return types.NewBlock(header, txs, nil, receipts, new(trie.Trie), nil), nil
 }
 
 // Authorize injects a private key into the consensus engine to mint new blocks
diff --git a/consensus/dummy/consensus.go b/consensus/dummy/consensus.go
index 2108684..da63673 100644
--- a/consensus/dummy/consensus.go
+++ b/consensus/dummy/consensus.go
@@ -13,14 +13,15 @@ import (
 	"github.com/ava-labs/coreth/core/types"
 	"github.com/ava-labs/coreth/params"
 	"github.com/ava-labs/coreth/rpc"
+	mapset "github.com/deckarep/golang-set"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/rlp"
-	mapset "github.com/deckarep/golang-set"
+	"github.com/ethereum/go-ethereum/trie"
 )
 
-type OnFinalizeCallbackType = func(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header)
+type OnFinalizeCallbackType = func(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header)
 type OnFinalizeAndAssembleCallbackType = func(state *state.StateDB, txs []*types.Transaction) ([]byte, error)
-type OnAPIsCallbackType = func(consensus.ChainReader) []rpc.API
+type OnAPIsCallbackType = func(consensus.ChainHeaderReader) []rpc.API
 type OnExtraStateChangeType = func(block *types.Block, statedb *state.StateDB) error
 
 type ConsensusCallbacks struct {
@@ -55,7 +56,7 @@ var (
 )
 
 // modified from consensus.go
-func (self *DummyEngine) verifyHeader(chain consensus.ChainReader, header, parent *types.Header, uncle bool, seal bool) error {
+func (self *DummyEngine) verifyHeader(chain consensus.ChainHeaderReader, header, parent *types.Header, uncle bool, seal bool) error {
 	// Ensure that the header's extra-data section is of a reasonable size
 	if uint64(len(header.Extra)) > params.MaximumExtraDataSize {
 		return fmt.Errorf("extra-data too long: %d > %d", len(header.Extra), params.MaximumExtraDataSize)
@@ -103,7 +104,7 @@ func (self *DummyEngine) verifyHeader(chain consensus.ChainReader, header, paren
 	return nil
 }
 
-func (self *DummyEngine) verifyHeaderWorker(chain consensus.ChainReader, headers []*types.Header, seals []bool, index int) error {
+func (self *DummyEngine) verifyHeaderWorker(chain consensus.ChainHeaderReader, headers []*types.Header, seals []bool, index int) error {
 	var parent *types.Header
 	if index == 0 {
 		parent = chain.GetHeader(headers[0].ParentHash, headers[0].Number.Uint64()-1)
@@ -123,7 +124,7 @@ func (self *DummyEngine) Author(header *types.Header) (common.Address, error) {
 	return header.Coinbase, nil
 }
 
-func (self *DummyEngine) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error {
+func (self *DummyEngine) VerifyHeader(chain consensus.ChainHeaderReader, header *types.Header, seal bool) error {
 	// Short circuit if the header is known, or it's parent not
 	number := header.Number.Uint64()
 	if chain.GetHeader(header.Hash(), number) != nil {
@@ -137,7 +138,7 @@ func (self *DummyEngine) VerifyHeader(chain consensus.ChainReader, header *types
 	return self.verifyHeader(chain, header, parent, false, seal)
 }
 
-func (self *DummyEngine) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
+func (self *DummyEngine) VerifyHeaders(chain consensus.ChainHeaderReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
 	// Spawn as many workers as allowed threads
 	workers := runtime.GOMAXPROCS(0)
 	if len(headers) < workers {
@@ -239,17 +240,17 @@ func (self *DummyEngine) VerifyUncles(chain consensus.ChainReader, block *types.
 	return nil
 }
 
-func (self *DummyEngine) VerifySeal(chain consensus.ChainReader, header *types.Header) error {
+func (self *DummyEngine) VerifySeal(chain consensus.ChainHeaderReader, header *types.Header) error {
 	return nil
 }
 
-func (self *DummyEngine) Prepare(chain consensus.ChainReader, header *types.Header) error {
+func (self *DummyEngine) Prepare(chain consensus.ChainHeaderReader, header *types.Header) error {
 	header.Difficulty = big.NewInt(1)
 	return nil
 }
 
 func (self *DummyEngine) Finalize(
-	chain consensus.ChainReader, header *types.Header,
+	chain consensus.ChainHeaderReader, header *types.Header,
 	state *state.StateDB, txs []*types.Transaction,
 	uncles []*types.Header) {
 	if self.cb.OnFinalize != nil {
@@ -259,7 +260,7 @@ func (self *DummyEngine) Finalize(
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
 }
 
-func (self *DummyEngine) FinalizeAndAssemble(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
+func (self *DummyEngine) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
 	uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
 	var extdata []byte
 	if self.cb.OnFinalizeAndAssemble != nil {
@@ -273,10 +274,10 @@ func (self *DummyEngine) FinalizeAndAssemble(chain consensus.ChainReader, header
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
 
 	// Header seems complete, assemble into a block and return
-	return types.NewBlock(header, txs, uncles, receipts, extdata), nil
+	return types.NewBlock(header, txs, uncles, receipts, new(trie.Trie), extdata), nil
 }
 
-func (self *DummyEngine) Seal(chain consensus.ChainReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) (err error) {
+func (self *DummyEngine) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) (err error) {
 	if self.cb.OnSeal != nil {
 		err = self.cb.OnSeal(block)
 	} else {
@@ -314,11 +315,11 @@ func (self *DummyEngine) SealHash(header *types.Header) (hash common.Hash) {
 	return hash
 }
 
-func (self *DummyEngine) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int {
+func (self *DummyEngine) CalcDifficulty(chain consensus.ChainHeaderReader, time uint64, parent *types.Header) *big.Int {
 	return big.NewInt(1)
 }
 
-func (self *DummyEngine) APIs(chain consensus.ChainReader) (res []rpc.API) {
+func (self *DummyEngine) APIs(chain consensus.ChainHeaderReader) (res []rpc.API) {
 	res = nil
 	if self.cb.OnAPIs != nil {
 		res = self.cb.OnAPIs(chain)
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index 151761c..dc56b6f 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -584,7 +584,7 @@ func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainHeaderReader, hea
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
 
 	// Header seems complete, assemble into a block and return
-	return types.NewBlock(header, txs, uncles, receipts, new(trie.Trie)), nil
+	return types.NewBlock(header, txs, uncles, receipts, new(trie.Trie), nil), nil
 }
 
 // SealHash returns the hash of a block prior to it being sealed.
diff --git a/core/blockchain.go b/core/blockchain.go
index b861220..82e3b6c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -2498,6 +2498,6 @@ func (bc *BlockChain) ManualHead(hash common.Hash) error {
 	}
 	bc.chainmu.Lock()
 	defer bc.chainmu.Unlock()
-	bc.insert(block)
+	bc.writeHeadBlock(block)
 	return nil
 }
diff --git a/core/forkid/forkid.go b/core/forkid/forkid.go
new file mode 100644
index 0000000..1d6563d
--- /dev/null
+++ b/core/forkid/forkid.go
@@ -0,0 +1,258 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package forkid implements EIP-2124 (https://eips.ethereum.org/EIPS/eip-2124).
+package forkid
+
+import (
+	"encoding/binary"
+	"errors"
+	"hash/crc32"
+	"math"
+	"math/big"
+	"reflect"
+	"strings"
+
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/coreth/params"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+var (
+	// ErrRemoteStale is returned by the validator if a remote fork checksum is a
+	// subset of our already applied forks, but the announced next fork block is
+	// not on our already passed chain.
+	ErrRemoteStale = errors.New("remote needs update")
+
+	// ErrLocalIncompatibleOrStale is returned by the validator if a remote fork
+	// checksum does not match any local checksum variation, signalling that the
+	// two chains have diverged in the past at some point (possibly at genesis).
+	ErrLocalIncompatibleOrStale = errors.New("local incompatible or needs update")
+)
+
+// Blockchain defines all necessary method to build a forkID.
+type Blockchain interface {
+	// Config retrieves the chain's fork configuration.
+	Config() *params.ChainConfig
+
+	// Genesis retrieves the chain's genesis block.
+	Genesis() *types.Block
+
+	// CurrentHeader retrieves the current head header of the canonical chain.
+	CurrentHeader() *types.Header
+}
+
+// ID is a fork identifier as defined by EIP-2124.
+type ID struct {
+	Hash [4]byte // CRC32 checksum of the genesis block and passed fork block numbers
+	Next uint64  // Block number of the next upcoming fork, or 0 if no forks are known
+}
+
+// Filter is a fork id filter to validate a remotely advertised ID.
+type Filter func(id ID) error
+
+// NewID calculates the Ethereum fork ID from the chain config and head.
+func NewID(chain Blockchain) ID {
+	return newID(
+		chain.Config(),
+		chain.Genesis().Hash(),
+		chain.CurrentHeader().Number.Uint64(),
+	)
+}
+
+// newID is the internal version of NewID, which takes extracted values as its
+// arguments instead of a chain. The reason is to allow testing the IDs without
+// having to simulate an entire blockchain.
+func newID(config *params.ChainConfig, genesis common.Hash, head uint64) ID {
+	// Calculate the starting checksum from the genesis hash
+	hash := crc32.ChecksumIEEE(genesis[:])
+
+	// Calculate the current fork checksum and the next fork block
+	var next uint64
+	for _, fork := range gatherForks(config) {
+		if fork <= head {
+			// Fork already passed, checksum the previous hash and the fork number
+			hash = checksumUpdate(hash, fork)
+			continue
+		}
+		next = fork
+		break
+	}
+	return ID{Hash: checksumToBytes(hash), Next: next}
+}
+
+// NewFilter creates a filter that returns if a fork ID should be rejected or not
+// based on the local chain's status.
+func NewFilter(chain Blockchain) Filter {
+	return newFilter(
+		chain.Config(),
+		chain.Genesis().Hash(),
+		func() uint64 {
+			return chain.CurrentHeader().Number.Uint64()
+		},
+	)
+}
+
+// NewStaticFilter creates a filter at block zero.
+func NewStaticFilter(config *params.ChainConfig, genesis common.Hash) Filter {
+	head := func() uint64 { return 0 }
+	return newFilter(config, genesis, head)
+}
+
+// newFilter is the internal version of NewFilter, taking closures as its arguments
+// instead of a chain. The reason is to allow testing it without having to simulate
+// an entire blockchain.
+func newFilter(config *params.ChainConfig, genesis common.Hash, headfn func() uint64) Filter {
+	// Calculate the all the valid fork hash and fork next combos
+	var (
+		forks = gatherForks(config)
+		sums  = make([][4]byte, len(forks)+1) // 0th is the genesis
+	)
+	hash := crc32.ChecksumIEEE(genesis[:])
+	sums[0] = checksumToBytes(hash)
+	for i, fork := range forks {
+		hash = checksumUpdate(hash, fork)
+		sums[i+1] = checksumToBytes(hash)
+	}
+	// Add two sentries to simplify the fork checks and don't require special
+	// casing the last one.
+	forks = append(forks, math.MaxUint64) // Last fork will never be passed
+
+	// Create a validator that will filter out incompatible chains
+	return func(id ID) error {
+		// Run the fork checksum validation ruleset:
+		//   1. If local and remote FORK_CSUM matches, compare local head to FORK_NEXT.
+		//        The two nodes are in the same fork state currently. They might know
+		//        of differing future forks, but that's not relevant until the fork
+		//        triggers (might be postponed, nodes might be updated to match).
+		//      1a. A remotely announced but remotely not passed block is already passed
+		//          locally, disconnect, since the chains are incompatible.
+		//      1b. No remotely announced fork; or not yet passed locally, connect.
+		//   2. If the remote FORK_CSUM is a subset of the local past forks and the
+		//      remote FORK_NEXT matches with the locally following fork block number,
+		//      connect.
+		//        Remote node is currently syncing. It might eventually diverge from
+		//        us, but at this current point in time we don't have enough information.
+		//   3. If the remote FORK_CSUM is a superset of the local past forks and can
+		//      be completed with locally known future forks, connect.
+		//        Local node is currently syncing. It might eventually diverge from
+		//        the remote, but at this current point in time we don't have enough
+		//        information.
+		//   4. Reject in all other cases.
+		head := headfn()
+		for i, fork := range forks {
+			// If our head is beyond this fork, continue to the next (we have a dummy
+			// fork of maxuint64 as the last item to always fail this check eventually).
+			if head > fork {
+				continue
+			}
+			// Found the first unpassed fork block, check if our current state matches
+			// the remote checksum (rule #1).
+			if sums[i] == id.Hash {
+				// Fork checksum matched, check if a remote future fork block already passed
+				// locally without the local node being aware of it (rule #1a).
+				if id.Next > 0 && head >= id.Next {
+					return ErrLocalIncompatibleOrStale
+				}
+				// Haven't passed locally a remote-only fork, accept the connection (rule #1b).
+				return nil
+			}
+			// The local and remote nodes are in different forks currently, check if the
+			// remote checksum is a subset of our local forks (rule #2).
+			for j := 0; j < i; j++ {
+				if sums[j] == id.Hash {
+					// Remote checksum is a subset, validate based on the announced next fork
+					if forks[j] != id.Next {
+						return ErrRemoteStale
+					}
+					return nil
+				}
+			}
+			// Remote chain is not a subset of our local one, check if it's a superset by
+			// any chance, signalling that we're simply out of sync (rule #3).
+			for j := i + 1; j < len(sums); j++ {
+				if sums[j] == id.Hash {
+					// Yay, remote checksum is a superset, ignore upcoming forks
+					return nil
+				}
+			}
+			// No exact, subset or superset match. We are on differing chains, reject.
+			return ErrLocalIncompatibleOrStale
+		}
+		log.Error("Impossible fork ID validation", "id", id)
+		return nil // Something's very wrong, accept rather than reject
+	}
+}
+
+// checksumUpdate calculates the next IEEE CRC32 checksum based on the previous
+// one and a fork block number (equivalent to CRC32(original-blob || fork)).
+func checksumUpdate(hash uint32, fork uint64) uint32 {
+	var blob [8]byte
+	binary.BigEndian.PutUint64(blob[:], fork)
+	return crc32.Update(hash, crc32.IEEETable, blob[:])
+}
+
+// checksumToBytes converts a uint32 checksum into a [4]byte array.
+func checksumToBytes(hash uint32) [4]byte {
+	var blob [4]byte
+	binary.BigEndian.PutUint32(blob[:], hash)
+	return blob
+}
+
+// gatherForks gathers all the known forks and creates a sorted list out of them.
+func gatherForks(config *params.ChainConfig) []uint64 {
+	// Gather all the fork block numbers via reflection
+	kind := reflect.TypeOf(params.ChainConfig{})
+	conf := reflect.ValueOf(config).Elem()
+
+	var forks []uint64
+	for i := 0; i < kind.NumField(); i++ {
+		// Fetch the next field and skip non-fork rules
+		field := kind.Field(i)
+		if !strings.HasSuffix(field.Name, "Block") {
+			continue
+		}
+		if field.Type != reflect.TypeOf(new(big.Int)) {
+			continue
+		}
+		// Extract the fork rule block number and aggregate it
+		rule := conf.Field(i).Interface().(*big.Int)
+		if rule != nil {
+			forks = append(forks, rule.Uint64())
+		}
+	}
+	// Sort the fork block numbers to permit chronological XOR
+	for i := 0; i < len(forks); i++ {
+		for j := i + 1; j < len(forks); j++ {
+			if forks[i] > forks[j] {
+				forks[i], forks[j] = forks[j], forks[i]
+			}
+		}
+	}
+	// Deduplicate block numbers applying multiple forks
+	for i := 1; i < len(forks); i++ {
+		if forks[i] == forks[i-1] {
+			forks = append(forks[:i], forks[i+1:]...)
+			i--
+		}
+	}
+	// Skip any forks in block 0, that's the genesis ruleset
+	if len(forks) > 0 && forks[0] == 0 {
+		forks = forks[1:]
+	}
+	return forks
+}
diff --git a/core/rawdb/accessors_state.go b/core/rawdb/accessors_state.go
new file mode 100644
index 0000000..6112de0
--- /dev/null
+++ b/core/rawdb/accessors_state.go
@@ -0,0 +1,96 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rawdb
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// ReadPreimage retrieves a single preimage of the provided hash.
+func ReadPreimage(db ethdb.KeyValueReader, hash common.Hash) []byte {
+	data, _ := db.Get(preimageKey(hash))
+	return data
+}
+
+// WritePreimages writes the provided set of preimages to the database.
+func WritePreimages(db ethdb.KeyValueWriter, preimages map[common.Hash][]byte) {
+	for hash, preimage := range preimages {
+		if err := db.Put(preimageKey(hash), preimage); err != nil {
+			log.Crit("Failed to store trie preimage", "err", err)
+		}
+	}
+	preimageCounter.Inc(int64(len(preimages)))
+	preimageHitCounter.Inc(int64(len(preimages)))
+}
+
+// ReadCode retrieves the contract code of the provided code hash.
+func ReadCode(db ethdb.KeyValueReader, hash common.Hash) []byte {
+	// Try with the legacy code scheme first, if not then try with current
+	// scheme. Since most of the code will be found with legacy scheme.
+	//
+	// todo(rjl493456442) change the order when we forcibly upgrade the code
+	// scheme with snapshot.
+	data, _ := db.Get(hash[:])
+	if len(data) != 0 {
+		return data
+	}
+	return ReadCodeWithPrefix(db, hash)
+}
+
+// ReadCodeWithPrefix retrieves the contract code of the provided code hash.
+// The main difference between this function and ReadCode is this function
+// will only check the existence with latest scheme(with prefix).
+func ReadCodeWithPrefix(db ethdb.KeyValueReader, hash common.Hash) []byte {
+	data, _ := db.Get(codeKey(hash))
+	return data
+}
+
+// WriteCode writes the provided contract code database.
+func WriteCode(db ethdb.KeyValueWriter, hash common.Hash, code []byte) {
+	if err := db.Put(codeKey(hash), code); err != nil {
+		log.Crit("Failed to store contract code", "err", err)
+	}
+}
+
+// DeleteCode deletes the specified contract code from the database.
+func DeleteCode(db ethdb.KeyValueWriter, hash common.Hash) {
+	if err := db.Delete(codeKey(hash)); err != nil {
+		log.Crit("Failed to delete contract code", "err", err)
+	}
+}
+
+// ReadTrieNode retrieves the trie node of the provided hash.
+func ReadTrieNode(db ethdb.KeyValueReader, hash common.Hash) []byte {
+	data, _ := db.Get(hash.Bytes())
+	return data
+}
+
+// WriteTrieNode writes the provided trie node database.
+func WriteTrieNode(db ethdb.KeyValueWriter, hash common.Hash, node []byte) {
+	if err := db.Put(hash.Bytes(), node); err != nil {
+		log.Crit("Failed to store trie node", "err", err)
+	}
+}
+
+// DeleteTrieNode deletes the specified trie node from the database.
+func DeleteTrieNode(db ethdb.KeyValueWriter, hash common.Hash) {
+	if err := db.Delete(hash.Bytes()); err != nil {
+		log.Crit("Failed to delete trie node", "err", err)
+	}
+}
diff --git a/core/rawdb/chain_iterator.go b/core/rawdb/chain_iterator.go
new file mode 100644
index 0000000..3130e92
--- /dev/null
+++ b/core/rawdb/chain_iterator.go
@@ -0,0 +1,304 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rawdb
+
+import (
+	"runtime"
+	"sync/atomic"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/prque"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rlp"
+	"golang.org/x/crypto/sha3"
+)
+
+// InitDatabaseFromFreezer reinitializes an empty database from a previous batch
+// of frozen ancient blocks. The method iterates over all the frozen blocks and
+// injects into the database the block hash->number mappings.
+func InitDatabaseFromFreezer(db ethdb.Database) {
+	// If we can't access the freezer or it's empty, abort
+	frozen, err := db.Ancients()
+	if err != nil || frozen == 0 {
+		return
+	}
+	var (
+		batch  = db.NewBatch()
+		start  = time.Now()
+		logged = start.Add(-7 * time.Second) // Unindex during import is fast, don't double log
+		hash   common.Hash
+	)
+	for i := uint64(0); i < frozen; i++ {
+		// Since the freezer has all data in sequential order on a file,
+		// it would be 'neat' to read more data in one go, and let the
+		// freezerdb return N items (e.g up to 1000 items per go)
+		// That would require an API change in Ancients though
+		if h, err := db.Ancient(freezerHashTable, i); err != nil {
+			log.Crit("Failed to init database from freezer", "err", err)
+		} else {
+			hash = common.BytesToHash(h)
+		}
+		WriteHeaderNumber(batch, hash, i)
+		// If enough data was accumulated in memory or we're at the last block, dump to disk
+		if batch.ValueSize() > ethdb.IdealBatchSize {
+			if err := batch.Write(); err != nil {
+				log.Crit("Failed to write data to db", "err", err)
+			}
+			batch.Reset()
+		}
+		// If we've spent too much time already, notify the user of what we're doing
+		if time.Since(logged) > 8*time.Second {
+			log.Info("Initializing database from freezer", "total", frozen, "number", i, "hash", hash, "elapsed", common.PrettyDuration(time.Since(start)))
+			logged = time.Now()
+		}
+	}
+	if err := batch.Write(); err != nil {
+		log.Crit("Failed to write data to db", "err", err)
+	}
+	batch.Reset()
+
+	WriteHeadHeaderHash(db, hash)
+	WriteHeadFastBlockHash(db, hash)
+	log.Info("Initialized database from freezer", "blocks", frozen, "elapsed", common.PrettyDuration(time.Since(start)))
+}
+
+type blockTxHashes struct {
+	number uint64
+	hashes []common.Hash
+}
+
+// iterateTransactions iterates over all transactions in the (canon) block
+// number(s) given, and yields the hashes on a channel
+func iterateTransactions(db ethdb.Database, from uint64, to uint64, reverse bool) (chan *blockTxHashes, chan struct{}) {
+	// One thread sequentially reads data from db
+	type numberRlp struct {
+		number uint64
+		rlp    rlp.RawValue
+	}
+	if to == from {
+		return nil, nil
+	}
+	threads := to - from
+	if cpus := runtime.NumCPU(); threads > uint64(cpus) {
+		threads = uint64(cpus)
+	}
+	var (
+		rlpCh    = make(chan *numberRlp, threads*2)     // we send raw rlp over this channel
+		hashesCh = make(chan *blockTxHashes, threads*2) // send hashes over hashesCh
+		abortCh  = make(chan struct{})
+	)
+	// lookup runs in one instance
+	lookup := func() {
+		n, end := from, to
+		if reverse {
+			n, end = to-1, from-1
+		}
+		defer close(rlpCh)
+		for n != end {
+			data := ReadCanonicalBodyRLP(db, n)
+			// Feed the block to the aggregator, or abort on interrupt
+			select {
+			case rlpCh <- &numberRlp{n, data}:
+			case <-abortCh:
+				return
+			}
+			if reverse {
+				n--
+			} else {
+				n++
+			}
+		}
+	}
+	// process runs in parallel
+	nThreadsAlive := int32(threads)
+	process := func() {
+		defer func() {
+			// Last processor closes the result channel
+			if atomic.AddInt32(&nThreadsAlive, -1) == 0 {
+				close(hashesCh)
+			}
+		}()
+
+		var hasher = sha3.NewLegacyKeccak256()
+		for data := range rlpCh {
+			it, err := rlp.NewListIterator(data.rlp)
+			if err != nil {
+				log.Warn("tx iteration error", "error", err)
+				return
+			}
+			it.Next()
+			txs := it.Value()
+			txIt, err := rlp.NewListIterator(txs)
+			if err != nil {
+				log.Warn("tx iteration error", "error", err)
+				return
+			}
+			var hashes []common.Hash
+			for txIt.Next() {
+				if err := txIt.Err(); err != nil {
+					log.Warn("tx iteration error", "error", err)
+					return
+				}
+				var txHash common.Hash
+				hasher.Reset()
+				hasher.Write(txIt.Value())
+				hasher.Sum(txHash[:0])
+				hashes = append(hashes, txHash)
+			}
+			result := &blockTxHashes{
+				hashes: hashes,
+				number: data.number,
+			}
+			// Feed the block to the aggregator, or abort on interrupt
+			select {
+			case hashesCh <- result:
+			case <-abortCh:
+				return
+			}
+		}
+	}
+	go lookup() // start the sequential db accessor
+	for i := 0; i < int(threads); i++ {
+		go process()
+	}
+	return hashesCh, abortCh
+}
+
+// IndexTransactions creates txlookup indices of the specified block range.
+//
+// This function iterates canonical chain in reverse order, it has one main advantage:
+// We can write tx index tail flag periodically even without the whole indexing
+// procedure is finished. So that we can resume indexing procedure next time quickly.
+func IndexTransactions(db ethdb.Database, from uint64, to uint64) {
+	// short circuit for invalid range
+	if from >= to {
+		return
+	}
+	var (
+		hashesCh, abortCh = iterateTransactions(db, from, to, true)
+		batch             = db.NewBatch()
+		start             = time.Now()
+		logged            = start.Add(-7 * time.Second)
+		//  Since we iterate in reverse, we expect the first number to come
+		// in to be [to-1]. Therefore, setting lastNum to means that the
+		// prqueue gap-evaluation will work correctly
+		lastNum = to
+		queue   = prque.New(nil)
+		// for stats reporting
+		blocks, txs = 0, 0
+	)
+	defer close(abortCh)
+
+	for chanDelivery := range hashesCh {
+		// Push the delivery into the queue and process contiguous ranges.
+		// Since we iterate in reverse, so lower numbers have lower prio, and
+		// we can use the number directly as prio marker
+		queue.Push(chanDelivery, int64(chanDelivery.number))
+		for !queue.Empty() {
+			// If the next available item is gapped, return
+			if _, priority := queue.Peek(); priority != int64(lastNum-1) {
+				break
+			}
+			// Next block available, pop it off and index it
+			delivery := queue.PopItem().(*blockTxHashes)
+			lastNum = delivery.number
+			WriteTxLookupEntries(batch, delivery.number, delivery.hashes)
+			blocks++
+			txs += len(delivery.hashes)
+			// If enough data was accumulated in memory or we're at the last block, dump to disk
+			if batch.ValueSize() > ethdb.IdealBatchSize {
+				// Also write the tail there
+				WriteTxIndexTail(batch, lastNum)
+				if err := batch.Write(); err != nil {
+					log.Crit("Failed writing batch to db", "error", err)
+					return
+				}
+				batch.Reset()
+			}
+			// If we've spent too much time already, notify the user of what we're doing
+			if time.Since(logged) > 8*time.Second {
+				log.Info("Indexing transactions", "blocks", blocks, "txs", txs, "tail", lastNum, "total", to-from, "elapsed", common.PrettyDuration(time.Since(start)))
+				logged = time.Now()
+			}
+		}
+	}
+	if lastNum < to {
+		WriteTxIndexTail(batch, lastNum)
+		// No need to write the batch if we never entered the loop above...
+		if err := batch.Write(); err != nil {
+			log.Crit("Failed writing batch to db", "error", err)
+			return
+		}
+	}
+	log.Info("Indexed transactions", "blocks", blocks, "txs", txs, "tail", lastNum, "elapsed", common.PrettyDuration(time.Since(start)))
+}
+
+// UnindexTransactions removes txlookup indices of the specified block range.
+func UnindexTransactions(db ethdb.Database, from uint64, to uint64) {
+	// short circuit for invalid range
+	if from >= to {
+		return
+	}
+	// Write flag first and then unindex the transaction indices. Some indices
+	// will be left in the database if crash happens but it's fine.
+	WriteTxIndexTail(db, to)
+	// If only one block is unindexed, do it directly
+	//if from+1 == to {
+	//	data := ReadCanonicalBodyRLP(db, uint64(from))
+	//	DeleteTxLookupEntries(db, ReadBlock(db, ReadCanonicalHash(db, from), from))
+	//	log.Info("Unindexed transactions", "blocks", 1, "tail", to)
+	//	return
+	//}
+	// TODO @holiman, add this back (if we want it)
+	var (
+		hashesCh, abortCh = iterateTransactions(db, from, to, false)
+		batch             = db.NewBatch()
+		start             = time.Now()
+		logged            = start.Add(-7 * time.Second)
+	)
+	defer close(abortCh)
+	// Otherwise spin up the concurrent iterator and unindexer
+	blocks, txs := 0, 0
+	for delivery := range hashesCh {
+		DeleteTxLookupEntries(batch, delivery.hashes)
+		txs += len(delivery.hashes)
+		blocks++
+
+		// If enough data was accumulated in memory or we're at the last block, dump to disk
+		// A batch counts the size of deletion as '1', so we need to flush more
+		// often than that.
+		if blocks%1000 == 0 {
+			if err := batch.Write(); err != nil {
+				log.Crit("Failed writing batch to db", "error", err)
+				return
+			}
+			batch.Reset()
+		}
+		// If we've spent too much time already, notify the user of what we're doing
+		if time.Since(logged) > 8*time.Second {
+			log.Info("Unindexing transactions", "blocks", blocks, "txs", txs, "total", to-from, "elapsed", common.PrettyDuration(time.Since(start)))
+			logged = time.Now()
+		}
+	}
+	if err := batch.Write(); err != nil {
+		log.Crit("Failed writing batch to db", "error", err)
+		return
+	}
+	log.Info("Unindexed transactions", "blocks", blocks, "txs", txs, "tail", to, "elapsed", common.PrettyDuration(time.Since(start)))
+}
diff --git a/core/state/snapshot/difflayer_test.go b/core/state/snapshot/difflayer_test.go
deleted file mode 100644
index 31636ee..0000000
--- a/core/state/snapshot/difflayer_test.go
+++ /dev/null
@@ -1,400 +0,0 @@
-// Copyright 2019 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package snapshot
-
-import (
-	"bytes"
-	"math/rand"
-	"testing"
-
-	"github.com/VictoriaMetrics/fastcache"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/ethdb/memorydb"
-)
-
-func copyDestructs(destructs map[common.Hash]struct{}) map[common.Hash]struct{} {
-	copy := make(map[common.Hash]struct{})
-	for hash := range destructs {
-		copy[hash] = struct{}{}
-	}
-	return copy
-}
-
-func copyAccounts(accounts map[common.Hash][]byte) map[common.Hash][]byte {
-	copy := make(map[common.Hash][]byte)
-	for hash, blob := range accounts {
-		copy[hash] = blob
-	}
-	return copy
-}
-
-func copyStorage(storage map[common.Hash]map[common.Hash][]byte) map[common.Hash]map[common.Hash][]byte {
-	copy := make(map[common.Hash]map[common.Hash][]byte)
-	for accHash, slots := range storage {
-		copy[accHash] = make(map[common.Hash][]byte)
-		for slotHash, blob := range slots {
-			copy[accHash][slotHash] = blob
-		}
-	}
-	return copy
-}
-
-// TestMergeBasics tests some simple merges
-func TestMergeBasics(t *testing.T) {
-	var (
-		destructs = make(map[common.Hash]struct{})
-		accounts  = make(map[common.Hash][]byte)
-		storage   = make(map[common.Hash]map[common.Hash][]byte)
-	)
-	// Fill up a parent
-	for i := 0; i < 100; i++ {
-		h := randomHash()
-		data := randomAccount()
-
-		accounts[h] = data
-		if rand.Intn(4) == 0 {
-			destructs[h] = struct{}{}
-		}
-		if rand.Intn(2) == 0 {
-			accStorage := make(map[common.Hash][]byte)
-			value := make([]byte, 32)
-			rand.Read(value)
-			accStorage[randomHash()] = value
-			storage[h] = accStorage
-		}
-	}
-	// Add some (identical) layers on top
-	parent := newDiffLayer(emptyLayer(), common.Hash{}, copyDestructs(destructs), copyAccounts(accounts), copyStorage(storage))
-	child := newDiffLayer(parent, common.Hash{}, copyDestructs(destructs), copyAccounts(accounts), copyStorage(storage))
-	child = newDiffLayer(child, common.Hash{}, copyDestructs(destructs), copyAccounts(accounts), copyStorage(storage))
-	child = newDiffLayer(child, common.Hash{}, copyDestructs(destructs), copyAccounts(accounts), copyStorage(storage))
-	child = newDiffLayer(child, common.Hash{}, copyDestructs(destructs), copyAccounts(accounts), copyStorage(storage))
-	// And flatten
-	merged := (child.flatten()).(*diffLayer)
-
-	{ // Check account lists
-		if have, want := len(merged.accountList), 0; have != want {
-			t.Errorf("accountList wrong: have %v, want %v", have, want)
-		}
-		if have, want := len(merged.AccountList()), len(accounts); have != want {
-			t.Errorf("AccountList() wrong: have %v, want %v", have, want)
-		}
-		if have, want := len(merged.accountList), len(accounts); have != want {
-			t.Errorf("accountList [2] wrong: have %v, want %v", have, want)
-		}
-	}
-	{ // Check account drops
-		if have, want := len(merged.destructSet), len(destructs); have != want {
-			t.Errorf("accountDrop wrong: have %v, want %v", have, want)
-		}
-	}
-	{ // Check storage lists
-		i := 0
-		for aHash, sMap := range storage {
-			if have, want := len(merged.storageList), i; have != want {
-				t.Errorf("[1] storageList wrong: have %v, want %v", have, want)
-			}
-			list, _ := merged.StorageList(aHash)
-			if have, want := len(list), len(sMap); have != want {
-				t.Errorf("[2] StorageList() wrong: have %v, want %v", have, want)
-			}
-			if have, want := len(merged.storageList[aHash]), len(sMap); have != want {
-				t.Errorf("storageList wrong: have %v, want %v", have, want)
-			}
-			i++
-		}
-	}
-}
-
-// TestMergeDelete tests some deletion
-func TestMergeDelete(t *testing.T) {
-	var (
-		storage = make(map[common.Hash]map[common.Hash][]byte)
-	)
-	// Fill up a parent
-	h1 := common.HexToHash("0x01")
-	h2 := common.HexToHash("0x02")
-
-	flipDrops := func() map[common.Hash]struct{} {
-		return map[common.Hash]struct{}{
-			h2: {},
-		}
-	}
-	flipAccs := func() map[common.Hash][]byte {
-		return map[common.Hash][]byte{
-			h1: randomAccount(),
-		}
-	}
-	flopDrops := func() map[common.Hash]struct{} {
-		return map[common.Hash]struct{}{
-			h1: {},
-		}
-	}
-	flopAccs := func() map[common.Hash][]byte {
-		return map[common.Hash][]byte{
-			h2: randomAccount(),
-		}
-	}
-	// Add some flipAccs-flopping layers on top
-	parent := newDiffLayer(emptyLayer(), common.Hash{}, flipDrops(), flipAccs(), storage)
-	child := parent.Update(common.Hash{}, flopDrops(), flopAccs(), storage)
-	child = child.Update(common.Hash{}, flipDrops(), flipAccs(), storage)
-	child = child.Update(common.Hash{}, flopDrops(), flopAccs(), storage)
-	child = child.Update(common.Hash{}, flipDrops(), flipAccs(), storage)
-	child = child.Update(common.Hash{}, flopDrops(), flopAccs(), storage)
-	child = child.Update(common.Hash{}, flipDrops(), flipAccs(), storage)
-
-	if data, _ := child.Account(h1); data == nil {
-		t.Errorf("last diff layer: expected %x account to be non-nil", h1)
-	}
-	if data, _ := child.Account(h2); data != nil {
-		t.Errorf("last diff layer: expected %x account to be nil", h2)
-	}
-	if _, ok := child.destructSet[h1]; ok {
-		t.Errorf("last diff layer: expected %x drop to be missing", h1)
-	}
-	if _, ok := child.destructSet[h2]; !ok {
-		t.Errorf("last diff layer: expected %x drop to be present", h1)
-	}
-	// And flatten
-	merged := (child.flatten()).(*diffLayer)
-
-	if data, _ := merged.Account(h1); data == nil {
-		t.Errorf("merged layer: expected %x account to be non-nil", h1)
-	}
-	if data, _ := merged.Account(h2); data != nil {
-		t.Errorf("merged layer: expected %x account to be nil", h2)
-	}
-	if _, ok := merged.destructSet[h1]; !ok { // Note, drops stay alive until persisted to disk!
-		t.Errorf("merged diff layer: expected %x drop to be present", h1)
-	}
-	if _, ok := merged.destructSet[h2]; !ok { // Note, drops stay alive until persisted to disk!
-		t.Errorf("merged diff layer: expected %x drop to be present", h1)
-	}
-	// If we add more granular metering of memory, we can enable this again,
-	// but it's not implemented for now
-	//if have, want := merged.memory, child.memory; have != want {
-	//	t.Errorf("mem wrong: have %d, want %d", have, want)
-	//}
-}
-
-// This tests that if we create a new account, and set a slot, and then merge
-// it, the lists will be correct.
-func TestInsertAndMerge(t *testing.T) {
-	// Fill up a parent
-	var (
-		acc    = common.HexToHash("0x01")
-		slot   = common.HexToHash("0x02")
-		parent *diffLayer
-		child  *diffLayer
-	)
-	{
-		var (
-			destructs = make(map[common.Hash]struct{})
-			accounts  = make(map[common.Hash][]byte)
-			storage   = make(map[common.Hash]map[common.Hash][]byte)
-		)
-		parent = newDiffLayer(emptyLayer(), common.Hash{}, destructs, accounts, storage)
-	}
-	{
-		var (
-			destructs = make(map[common.Hash]struct{})
-			accounts  = make(map[common.Hash][]byte)
-			storage   = make(map[common.Hash]map[common.Hash][]byte)
-		)
-		accounts[acc] = randomAccount()
-		storage[acc] = make(map[common.Hash][]byte)
-		storage[acc][slot] = []byte{0x01}
-		child = newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
-	}
-	// And flatten
-	merged := (child.flatten()).(*diffLayer)
-	{ // Check that slot value is present
-		have, _ := merged.Storage(acc, slot)
-		if want := []byte{0x01}; !bytes.Equal(have, want) {
-			t.Errorf("merged slot value wrong: have %x, want %x", have, want)
-		}
-	}
-}
-
-func emptyLayer() *diskLayer {
-	return &diskLayer{
-		diskdb: memorydb.New(),
-		cache:  fastcache.New(500 * 1024),
-	}
-}
-
-// BenchmarkSearch checks how long it takes to find a non-existing key
-// BenchmarkSearch-6   	  200000	     10481 ns/op (1K per layer)
-// BenchmarkSearch-6   	  200000	     10760 ns/op (10K per layer)
-// BenchmarkSearch-6   	  100000	     17866 ns/op
-//
-// BenchmarkSearch-6   	  500000	      3723 ns/op (10k per layer, only top-level RLock()
-func BenchmarkSearch(b *testing.B) {
-	// First, we set up 128 diff layers, with 1K items each
-	fill := func(parent snapshot) *diffLayer {
-		var (
-			destructs = make(map[common.Hash]struct{})
-			accounts  = make(map[common.Hash][]byte)
-			storage   = make(map[common.Hash]map[common.Hash][]byte)
-		)
-		for i := 0; i < 10000; i++ {
-			accounts[randomHash()] = randomAccount()
-		}
-		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
-	}
-	var layer snapshot
-	layer = emptyLayer()
-	for i := 0; i < 128; i++ {
-		layer = fill(layer)
-	}
-	key := crypto.Keccak256Hash([]byte{0x13, 0x38})
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		layer.AccountRLP(key)
-	}
-}
-
-// BenchmarkSearchSlot checks how long it takes to find a non-existing key
-// - Number of layers: 128
-// - Each layers contains the account, with a couple of storage slots
-// BenchmarkSearchSlot-6   	  100000	     14554 ns/op
-// BenchmarkSearchSlot-6   	  100000	     22254 ns/op (when checking parent root using mutex)
-// BenchmarkSearchSlot-6   	  100000	     14551 ns/op (when checking parent number using atomic)
-// With bloom filter:
-// BenchmarkSearchSlot-6   	 3467835	       351 ns/op
-func BenchmarkSearchSlot(b *testing.B) {
-	// First, we set up 128 diff layers, with 1K items each
-	accountKey := crypto.Keccak256Hash([]byte{0x13, 0x37})
-	storageKey := crypto.Keccak256Hash([]byte{0x13, 0x37})
-	accountRLP := randomAccount()
-	fill := func(parent snapshot) *diffLayer {
-		var (
-			destructs = make(map[common.Hash]struct{})
-			accounts  = make(map[common.Hash][]byte)
-			storage   = make(map[common.Hash]map[common.Hash][]byte)
-		)
-		accounts[accountKey] = accountRLP
-
-		accStorage := make(map[common.Hash][]byte)
-		for i := 0; i < 5; i++ {
-			value := make([]byte, 32)
-			rand.Read(value)
-			accStorage[randomHash()] = value
-			storage[accountKey] = accStorage
-		}
-		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
-	}
-	var layer snapshot
-	layer = emptyLayer()
-	for i := 0; i < 128; i++ {
-		layer = fill(layer)
-	}
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		layer.Storage(accountKey, storageKey)
-	}
-}
-
-// With accountList and sorting
-// BenchmarkFlatten-6   	      50	  29890856 ns/op
-//
-// Without sorting and tracking accountlist
-// BenchmarkFlatten-6   	     300	   5511511 ns/op
-func BenchmarkFlatten(b *testing.B) {
-	fill := func(parent snapshot) *diffLayer {
-		var (
-			destructs = make(map[common.Hash]struct{})
-			accounts  = make(map[common.Hash][]byte)
-			storage   = make(map[common.Hash]map[common.Hash][]byte)
-		)
-		for i := 0; i < 100; i++ {
-			accountKey := randomHash()
-			accounts[accountKey] = randomAccount()
-
-			accStorage := make(map[common.Hash][]byte)
-			for i := 0; i < 20; i++ {
-				value := make([]byte, 32)
-				rand.Read(value)
-				accStorage[randomHash()] = value
-
-			}
-			storage[accountKey] = accStorage
-		}
-		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
-	}
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		b.StopTimer()
-		var layer snapshot
-		layer = emptyLayer()
-		for i := 1; i < 128; i++ {
-			layer = fill(layer)
-		}
-		b.StartTimer()
-
-		for i := 1; i < 128; i++ {
-			dl, ok := layer.(*diffLayer)
-			if !ok {
-				break
-			}
-			layer = dl.flatten()
-		}
-		b.StopTimer()
-	}
-}
-
-// This test writes ~324M of diff layers to disk, spread over
-// - 128 individual layers,
-// - each with 200 accounts
-// - containing 200 slots
-//
-// BenchmarkJournal-6   	       1	1471373923 ns/ops
-// BenchmarkJournal-6   	       1	1208083335 ns/op // bufio writer
-func BenchmarkJournal(b *testing.B) {
-	fill := func(parent snapshot) *diffLayer {
-		var (
-			destructs = make(map[common.Hash]struct{})
-			accounts  = make(map[common.Hash][]byte)
-			storage   = make(map[common.Hash]map[common.Hash][]byte)
-		)
-		for i := 0; i < 200; i++ {
-			accountKey := randomHash()
-			accounts[accountKey] = randomAccount()
-
-			accStorage := make(map[common.Hash][]byte)
-			for i := 0; i < 200; i++ {
-				value := make([]byte, 32)
-				rand.Read(value)
-				accStorage[randomHash()] = value
-
-			}
-			storage[accountKey] = accStorage
-		}
-		return newDiffLayer(parent, common.Hash{}, destructs, accounts, storage)
-	}
-	layer := snapshot(new(diskLayer))
-	for i := 1; i < 128; i++ {
-		layer = fill(layer)
-	}
-	b.ResetTimer()
-
-	for i := 0; i < b.N; i++ {
-		layer.Journal(new(bytes.Buffer))
-	}
-}
diff --git a/core/state/snapshot/disklayer_test.go b/core/state/snapshot/disklayer_test.go
deleted file mode 100644
index 5df5efc..0000000
--- a/core/state/snapshot/disklayer_test.go
+++ /dev/null
@@ -1,511 +0,0 @@
-// Copyright 2019 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package snapshot
-
-import (
-	"bytes"
-	"io/ioutil"
-	"os"
-	"testing"
-
-	"github.com/VictoriaMetrics/fastcache"
-	"github.com/ava-labs/coreth/core/rawdb"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/ethdb"
-	"github.com/ethereum/go-ethereum/ethdb/leveldb"
-	"github.com/ethereum/go-ethereum/ethdb/memorydb"
-)
-
-// reverse reverses the contents of a byte slice. It's used to update random accs
-// with deterministic changes.
-func reverse(blob []byte) []byte {
-	res := make([]byte, len(blob))
-	for i, b := range blob {
-		res[len(blob)-1-i] = b
-	}
-	return res
-}
-
-// Tests that merging something into a disk layer persists it into the database
-// and invalidates any previously written and cached values.
-func TestDiskMerge(t *testing.T) {
-	// Create some accounts in the disk layer
-	db := memorydb.New()
-
-	var (
-		accNoModNoCache     = common.Hash{0x1}
-		accNoModCache       = common.Hash{0x2}
-		accModNoCache       = common.Hash{0x3}
-		accModCache         = common.Hash{0x4}
-		accDelNoCache       = common.Hash{0x5}
-		accDelCache         = common.Hash{0x6}
-		conNoModNoCache     = common.Hash{0x7}
-		conNoModNoCacheSlot = common.Hash{0x70}
-		conNoModCache       = common.Hash{0x8}
-		conNoModCacheSlot   = common.Hash{0x80}
-		conModNoCache       = common.Hash{0x9}
-		conModNoCacheSlot   = common.Hash{0x90}
-		conModCache         = common.Hash{0xa}
-		conModCacheSlot     = common.Hash{0xa0}
-		conDelNoCache       = common.Hash{0xb}
-		conDelNoCacheSlot   = common.Hash{0xb0}
-		conDelCache         = common.Hash{0xc}
-		conDelCacheSlot     = common.Hash{0xc0}
-		conNukeNoCache      = common.Hash{0xd}
-		conNukeNoCacheSlot  = common.Hash{0xd0}
-		conNukeCache        = common.Hash{0xe}
-		conNukeCacheSlot    = common.Hash{0xe0}
-		baseRoot            = randomHash()
-		diffRoot            = randomHash()
-	)
-
-	rawdb.WriteAccountSnapshot(db, accNoModNoCache, accNoModNoCache[:])
-	rawdb.WriteAccountSnapshot(db, accNoModCache, accNoModCache[:])
-	rawdb.WriteAccountSnapshot(db, accModNoCache, accModNoCache[:])
-	rawdb.WriteAccountSnapshot(db, accModCache, accModCache[:])
-	rawdb.WriteAccountSnapshot(db, accDelNoCache, accDelNoCache[:])
-	rawdb.WriteAccountSnapshot(db, accDelCache, accDelCache[:])
-
-	rawdb.WriteAccountSnapshot(db, conNoModNoCache, conNoModNoCache[:])
-	rawdb.WriteStorageSnapshot(db, conNoModNoCache, conNoModNoCacheSlot, conNoModNoCacheSlot[:])
-	rawdb.WriteAccountSnapshot(db, conNoModCache, conNoModCache[:])
-	rawdb.WriteStorageSnapshot(db, conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-	rawdb.WriteAccountSnapshot(db, conModNoCache, conModNoCache[:])
-	rawdb.WriteStorageSnapshot(db, conModNoCache, conModNoCacheSlot, conModNoCacheSlot[:])
-	rawdb.WriteAccountSnapshot(db, conModCache, conModCache[:])
-	rawdb.WriteStorageSnapshot(db, conModCache, conModCacheSlot, conModCacheSlot[:])
-	rawdb.WriteAccountSnapshot(db, conDelNoCache, conDelNoCache[:])
-	rawdb.WriteStorageSnapshot(db, conDelNoCache, conDelNoCacheSlot, conDelNoCacheSlot[:])
-	rawdb.WriteAccountSnapshot(db, conDelCache, conDelCache[:])
-	rawdb.WriteStorageSnapshot(db, conDelCache, conDelCacheSlot, conDelCacheSlot[:])
-
-	rawdb.WriteAccountSnapshot(db, conNukeNoCache, conNukeNoCache[:])
-	rawdb.WriteStorageSnapshot(db, conNukeNoCache, conNukeNoCacheSlot, conNukeNoCacheSlot[:])
-	rawdb.WriteAccountSnapshot(db, conNukeCache, conNukeCache[:])
-	rawdb.WriteStorageSnapshot(db, conNukeCache, conNukeCacheSlot, conNukeCacheSlot[:])
-
-	rawdb.WriteSnapshotRoot(db, baseRoot)
-
-	// Create a disk layer based on the above and cache in some data
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			baseRoot: &diskLayer{
-				diskdb: db,
-				cache:  fastcache.New(500 * 1024),
-				root:   baseRoot,
-			},
-		},
-	}
-	base := snaps.Snapshot(baseRoot)
-	base.AccountRLP(accNoModCache)
-	base.AccountRLP(accModCache)
-	base.AccountRLP(accDelCache)
-	base.Storage(conNoModCache, conNoModCacheSlot)
-	base.Storage(conModCache, conModCacheSlot)
-	base.Storage(conDelCache, conDelCacheSlot)
-	base.Storage(conNukeCache, conNukeCacheSlot)
-
-	// Modify or delete some accounts, flatten everything onto disk
-	if err := snaps.Update(diffRoot, baseRoot, map[common.Hash]struct{}{
-		accDelNoCache:  {},
-		accDelCache:    {},
-		conNukeNoCache: {},
-		conNukeCache:   {},
-	}, map[common.Hash][]byte{
-		accModNoCache: reverse(accModNoCache[:]),
-		accModCache:   reverse(accModCache[:]),
-	}, map[common.Hash]map[common.Hash][]byte{
-		conModNoCache: {conModNoCacheSlot: reverse(conModNoCacheSlot[:])},
-		conModCache:   {conModCacheSlot: reverse(conModCacheSlot[:])},
-		conDelNoCache: {conDelNoCacheSlot: nil},
-		conDelCache:   {conDelCacheSlot: nil},
-	}); err != nil {
-		t.Fatalf("failed to update snapshot tree: %v", err)
-	}
-	if err := snaps.Cap(diffRoot, 0); err != nil {
-		t.Fatalf("failed to flatten snapshot tree: %v", err)
-	}
-	// Retrieve all the data through the disk layer and validate it
-	base = snaps.Snapshot(diffRoot)
-	if _, ok := base.(*diskLayer); !ok {
-		t.Fatalf("update not flattend into the disk layer")
-	}
-
-	// assertAccount ensures that an account matches the given blob.
-	assertAccount := func(account common.Hash, data []byte) {
-		t.Helper()
-		blob, err := base.AccountRLP(account)
-		if err != nil {
-			t.Errorf("account access (%x) failed: %v", account, err)
-		} else if !bytes.Equal(blob, data) {
-			t.Errorf("account access (%x) mismatch: have %x, want %x", account, blob, data)
-		}
-	}
-	assertAccount(accNoModNoCache, accNoModNoCache[:])
-	assertAccount(accNoModCache, accNoModCache[:])
-	assertAccount(accModNoCache, reverse(accModNoCache[:]))
-	assertAccount(accModCache, reverse(accModCache[:]))
-	assertAccount(accDelNoCache, nil)
-	assertAccount(accDelCache, nil)
-
-	// assertStorage ensures that a storage slot matches the given blob.
-	assertStorage := func(account common.Hash, slot common.Hash, data []byte) {
-		t.Helper()
-		blob, err := base.Storage(account, slot)
-		if err != nil {
-			t.Errorf("storage access (%x:%x) failed: %v", account, slot, err)
-		} else if !bytes.Equal(blob, data) {
-			t.Errorf("storage access (%x:%x) mismatch: have %x, want %x", account, slot, blob, data)
-		}
-	}
-	assertStorage(conNoModNoCache, conNoModNoCacheSlot, conNoModNoCacheSlot[:])
-	assertStorage(conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-	assertStorage(conModNoCache, conModNoCacheSlot, reverse(conModNoCacheSlot[:]))
-	assertStorage(conModCache, conModCacheSlot, reverse(conModCacheSlot[:]))
-	assertStorage(conDelNoCache, conDelNoCacheSlot, nil)
-	assertStorage(conDelCache, conDelCacheSlot, nil)
-	assertStorage(conNukeNoCache, conNukeNoCacheSlot, nil)
-	assertStorage(conNukeCache, conNukeCacheSlot, nil)
-
-	// Retrieve all the data directly from the database and validate it
-
-	// assertDatabaseAccount ensures that an account from the database matches the given blob.
-	assertDatabaseAccount := func(account common.Hash, data []byte) {
-		t.Helper()
-		if blob := rawdb.ReadAccountSnapshot(db, account); !bytes.Equal(blob, data) {
-			t.Errorf("account database access (%x) mismatch: have %x, want %x", account, blob, data)
-		}
-	}
-	assertDatabaseAccount(accNoModNoCache, accNoModNoCache[:])
-	assertDatabaseAccount(accNoModCache, accNoModCache[:])
-	assertDatabaseAccount(accModNoCache, reverse(accModNoCache[:]))
-	assertDatabaseAccount(accModCache, reverse(accModCache[:]))
-	assertDatabaseAccount(accDelNoCache, nil)
-	assertDatabaseAccount(accDelCache, nil)
-
-	// assertDatabaseStorage ensures that a storage slot from the database matches the given blob.
-	assertDatabaseStorage := func(account common.Hash, slot common.Hash, data []byte) {
-		t.Helper()
-		if blob := rawdb.ReadStorageSnapshot(db, account, slot); !bytes.Equal(blob, data) {
-			t.Errorf("storage database access (%x:%x) mismatch: have %x, want %x", account, slot, blob, data)
-		}
-	}
-	assertDatabaseStorage(conNoModNoCache, conNoModNoCacheSlot, conNoModNoCacheSlot[:])
-	assertDatabaseStorage(conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-	assertDatabaseStorage(conModNoCache, conModNoCacheSlot, reverse(conModNoCacheSlot[:]))
-	assertDatabaseStorage(conModCache, conModCacheSlot, reverse(conModCacheSlot[:]))
-	assertDatabaseStorage(conDelNoCache, conDelNoCacheSlot, nil)
-	assertDatabaseStorage(conDelCache, conDelCacheSlot, nil)
-	assertDatabaseStorage(conNukeNoCache, conNukeNoCacheSlot, nil)
-	assertDatabaseStorage(conNukeCache, conNukeCacheSlot, nil)
-}
-
-// Tests that merging something into a disk layer persists it into the database
-// and invalidates any previously written and cached values, discarding anything
-// after the in-progress generation marker.
-func TestDiskPartialMerge(t *testing.T) {
-	// Iterate the test a few times to ensure we pick various internal orderings
-	// for the data slots as well as the progress marker.
-	for i := 0; i < 1024; i++ {
-		// Create some accounts in the disk layer
-		db := memorydb.New()
-
-		var (
-			accNoModNoCache     = randomHash()
-			accNoModCache       = randomHash()
-			accModNoCache       = randomHash()
-			accModCache         = randomHash()
-			accDelNoCache       = randomHash()
-			accDelCache         = randomHash()
-			conNoModNoCache     = randomHash()
-			conNoModNoCacheSlot = randomHash()
-			conNoModCache       = randomHash()
-			conNoModCacheSlot   = randomHash()
-			conModNoCache       = randomHash()
-			conModNoCacheSlot   = randomHash()
-			conModCache         = randomHash()
-			conModCacheSlot     = randomHash()
-			conDelNoCache       = randomHash()
-			conDelNoCacheSlot   = randomHash()
-			conDelCache         = randomHash()
-			conDelCacheSlot     = randomHash()
-			conNukeNoCache      = randomHash()
-			conNukeNoCacheSlot  = randomHash()
-			conNukeCache        = randomHash()
-			conNukeCacheSlot    = randomHash()
-			baseRoot            = randomHash()
-			diffRoot            = randomHash()
-			genMarker           = append(randomHash().Bytes(), randomHash().Bytes()...)
-		)
-
-		// insertAccount injects an account into the database if it's after the
-		// generator marker, drops the op otherwise. This is needed to seed the
-		// database with a valid starting snapshot.
-		insertAccount := func(account common.Hash, data []byte) {
-			if bytes.Compare(account[:], genMarker) <= 0 {
-				rawdb.WriteAccountSnapshot(db, account, data[:])
-			}
-		}
-		insertAccount(accNoModNoCache, accNoModNoCache[:])
-		insertAccount(accNoModCache, accNoModCache[:])
-		insertAccount(accModNoCache, accModNoCache[:])
-		insertAccount(accModCache, accModCache[:])
-		insertAccount(accDelNoCache, accDelNoCache[:])
-		insertAccount(accDelCache, accDelCache[:])
-
-		// insertStorage injects a storage slot into the database if it's after
-		// the  generator marker, drops the op otherwise. This is needed to seed
-		// the  database with a valid starting snapshot.
-		insertStorage := func(account common.Hash, slot common.Hash, data []byte) {
-			if bytes.Compare(append(account[:], slot[:]...), genMarker) <= 0 {
-				rawdb.WriteStorageSnapshot(db, account, slot, data[:])
-			}
-		}
-		insertAccount(conNoModNoCache, conNoModNoCache[:])
-		insertStorage(conNoModNoCache, conNoModNoCacheSlot, conNoModNoCacheSlot[:])
-		insertAccount(conNoModCache, conNoModCache[:])
-		insertStorage(conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-		insertAccount(conModNoCache, conModNoCache[:])
-		insertStorage(conModNoCache, conModNoCacheSlot, conModNoCacheSlot[:])
-		insertAccount(conModCache, conModCache[:])
-		insertStorage(conModCache, conModCacheSlot, conModCacheSlot[:])
-		insertAccount(conDelNoCache, conDelNoCache[:])
-		insertStorage(conDelNoCache, conDelNoCacheSlot, conDelNoCacheSlot[:])
-		insertAccount(conDelCache, conDelCache[:])
-		insertStorage(conDelCache, conDelCacheSlot, conDelCacheSlot[:])
-
-		insertAccount(conNukeNoCache, conNukeNoCache[:])
-		insertStorage(conNukeNoCache, conNukeNoCacheSlot, conNukeNoCacheSlot[:])
-		insertAccount(conNukeCache, conNukeCache[:])
-		insertStorage(conNukeCache, conNukeCacheSlot, conNukeCacheSlot[:])
-
-		rawdb.WriteSnapshotRoot(db, baseRoot)
-
-		// Create a disk layer based on the above using a random progress marker
-		// and cache in some data.
-		snaps := &Tree{
-			layers: map[common.Hash]snapshot{
-				baseRoot: &diskLayer{
-					diskdb: db,
-					cache:  fastcache.New(500 * 1024),
-					root:   baseRoot,
-				},
-			},
-		}
-		snaps.layers[baseRoot].(*diskLayer).genMarker = genMarker
-		base := snaps.Snapshot(baseRoot)
-
-		// assertAccount ensures that an account matches the given blob if it's
-		// already covered by the disk snapshot, and errors out otherwise.
-		assertAccount := func(account common.Hash, data []byte) {
-			t.Helper()
-			blob, err := base.AccountRLP(account)
-			if bytes.Compare(account[:], genMarker) > 0 && err != ErrNotCoveredYet {
-				t.Fatalf("test %d: post-marker (%x) account access (%x) succeeded: %x", i, genMarker, account, blob)
-			}
-			if bytes.Compare(account[:], genMarker) <= 0 && !bytes.Equal(blob, data) {
-				t.Fatalf("test %d: pre-marker (%x) account access (%x) mismatch: have %x, want %x", i, genMarker, account, blob, data)
-			}
-		}
-		assertAccount(accNoModCache, accNoModCache[:])
-		assertAccount(accModCache, accModCache[:])
-		assertAccount(accDelCache, accDelCache[:])
-
-		// assertStorage ensures that a storage slot matches the given blob if
-		// it's already covered by the disk snapshot, and errors out otherwise.
-		assertStorage := func(account common.Hash, slot common.Hash, data []byte) {
-			t.Helper()
-			blob, err := base.Storage(account, slot)
-			if bytes.Compare(append(account[:], slot[:]...), genMarker) > 0 && err != ErrNotCoveredYet {
-				t.Fatalf("test %d: post-marker (%x) storage access (%x:%x) succeeded: %x", i, genMarker, account, slot, blob)
-			}
-			if bytes.Compare(append(account[:], slot[:]...), genMarker) <= 0 && !bytes.Equal(blob, data) {
-				t.Fatalf("test %d: pre-marker (%x) storage access (%x:%x) mismatch: have %x, want %x", i, genMarker, account, slot, blob, data)
-			}
-		}
-		assertStorage(conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-		assertStorage(conModCache, conModCacheSlot, conModCacheSlot[:])
-		assertStorage(conDelCache, conDelCacheSlot, conDelCacheSlot[:])
-		assertStorage(conNukeCache, conNukeCacheSlot, conNukeCacheSlot[:])
-
-		// Modify or delete some accounts, flatten everything onto disk
-		if err := snaps.Update(diffRoot, baseRoot, map[common.Hash]struct{}{
-			accDelNoCache:  {},
-			accDelCache:    {},
-			conNukeNoCache: {},
-			conNukeCache:   {},
-		}, map[common.Hash][]byte{
-			accModNoCache: reverse(accModNoCache[:]),
-			accModCache:   reverse(accModCache[:]),
-		}, map[common.Hash]map[common.Hash][]byte{
-			conModNoCache: {conModNoCacheSlot: reverse(conModNoCacheSlot[:])},
-			conModCache:   {conModCacheSlot: reverse(conModCacheSlot[:])},
-			conDelNoCache: {conDelNoCacheSlot: nil},
-			conDelCache:   {conDelCacheSlot: nil},
-		}); err != nil {
-			t.Fatalf("test %d: failed to update snapshot tree: %v", i, err)
-		}
-		if err := snaps.Cap(diffRoot, 0); err != nil {
-			t.Fatalf("test %d: failed to flatten snapshot tree: %v", i, err)
-		}
-		// Retrieve all the data through the disk layer and validate it
-		base = snaps.Snapshot(diffRoot)
-		if _, ok := base.(*diskLayer); !ok {
-			t.Fatalf("test %d: update not flattend into the disk layer", i)
-		}
-		assertAccount(accNoModNoCache, accNoModNoCache[:])
-		assertAccount(accNoModCache, accNoModCache[:])
-		assertAccount(accModNoCache, reverse(accModNoCache[:]))
-		assertAccount(accModCache, reverse(accModCache[:]))
-		assertAccount(accDelNoCache, nil)
-		assertAccount(accDelCache, nil)
-
-		assertStorage(conNoModNoCache, conNoModNoCacheSlot, conNoModNoCacheSlot[:])
-		assertStorage(conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-		assertStorage(conModNoCache, conModNoCacheSlot, reverse(conModNoCacheSlot[:]))
-		assertStorage(conModCache, conModCacheSlot, reverse(conModCacheSlot[:]))
-		assertStorage(conDelNoCache, conDelNoCacheSlot, nil)
-		assertStorage(conDelCache, conDelCacheSlot, nil)
-		assertStorage(conNukeNoCache, conNukeNoCacheSlot, nil)
-		assertStorage(conNukeCache, conNukeCacheSlot, nil)
-
-		// Retrieve all the data directly from the database and validate it
-
-		// assertDatabaseAccount ensures that an account inside the database matches
-		// the given blob if it's already covered by the disk snapshot, and does not
-		// exist otherwise.
-		assertDatabaseAccount := func(account common.Hash, data []byte) {
-			t.Helper()
-			blob := rawdb.ReadAccountSnapshot(db, account)
-			if bytes.Compare(account[:], genMarker) > 0 && blob != nil {
-				t.Fatalf("test %d: post-marker (%x) account database access (%x) succeeded: %x", i, genMarker, account, blob)
-			}
-			if bytes.Compare(account[:], genMarker) <= 0 && !bytes.Equal(blob, data) {
-				t.Fatalf("test %d: pre-marker (%x) account database access (%x) mismatch: have %x, want %x", i, genMarker, account, blob, data)
-			}
-		}
-		assertDatabaseAccount(accNoModNoCache, accNoModNoCache[:])
-		assertDatabaseAccount(accNoModCache, accNoModCache[:])
-		assertDatabaseAccount(accModNoCache, reverse(accModNoCache[:]))
-		assertDatabaseAccount(accModCache, reverse(accModCache[:]))
-		assertDatabaseAccount(accDelNoCache, nil)
-		assertDatabaseAccount(accDelCache, nil)
-
-		// assertDatabaseStorage ensures that a storage slot inside the database
-		// matches the given blob if it's already covered by the disk snapshot,
-		// and does not exist otherwise.
-		assertDatabaseStorage := func(account common.Hash, slot common.Hash, data []byte) {
-			t.Helper()
-			blob := rawdb.ReadStorageSnapshot(db, account, slot)
-			if bytes.Compare(append(account[:], slot[:]...), genMarker) > 0 && blob != nil {
-				t.Fatalf("test %d: post-marker (%x) storage database access (%x:%x) succeeded: %x", i, genMarker, account, slot, blob)
-			}
-			if bytes.Compare(append(account[:], slot[:]...), genMarker) <= 0 && !bytes.Equal(blob, data) {
-				t.Fatalf("test %d: pre-marker (%x) storage database access (%x:%x) mismatch: have %x, want %x", i, genMarker, account, slot, blob, data)
-			}
-		}
-		assertDatabaseStorage(conNoModNoCache, conNoModNoCacheSlot, conNoModNoCacheSlot[:])
-		assertDatabaseStorage(conNoModCache, conNoModCacheSlot, conNoModCacheSlot[:])
-		assertDatabaseStorage(conModNoCache, conModNoCacheSlot, reverse(conModNoCacheSlot[:]))
-		assertDatabaseStorage(conModCache, conModCacheSlot, reverse(conModCacheSlot[:]))
-		assertDatabaseStorage(conDelNoCache, conDelNoCacheSlot, nil)
-		assertDatabaseStorage(conDelCache, conDelCacheSlot, nil)
-		assertDatabaseStorage(conNukeNoCache, conNukeNoCacheSlot, nil)
-		assertDatabaseStorage(conNukeCache, conNukeCacheSlot, nil)
-	}
-}
-
-// Tests that merging something into a disk layer persists it into the database
-// and invalidates any previously written and cached values, discarding anything
-// after the in-progress generation marker.
-//
-// This test case is a tiny specialized case of TestDiskPartialMerge, which tests
-// some very specific cornercases that random tests won't ever trigger.
-func TestDiskMidAccountPartialMerge(t *testing.T) {
-	// TODO(@karalabe) ?
-}
-
-// TestDiskSeek tests that seek-operations work on the disk layer
-func TestDiskSeek(t *testing.T) {
-	// Create some accounts in the disk layer
-	var db ethdb.Database
-
-	if dir, err := ioutil.TempDir("", "disklayer-test"); err != nil {
-		t.Fatal(err)
-	} else {
-		defer os.RemoveAll(dir)
-		diskdb, err := leveldb.New(dir, 256, 0, "")
-		if err != nil {
-			t.Fatal(err)
-		}
-		db = rawdb.NewDatabase(diskdb)
-	}
-	// Fill even keys [0,2,4...]
-	for i := 0; i < 0xff; i += 2 {
-		acc := common.Hash{byte(i)}
-		rawdb.WriteAccountSnapshot(db, acc, acc[:])
-	}
-	// Add an 'higher' key, with incorrect (higher) prefix
-	highKey := []byte{rawdb.SnapshotAccountPrefix[0] + 1}
-	db.Put(highKey, []byte{0xff, 0xff})
-
-	baseRoot := randomHash()
-	rawdb.WriteSnapshotRoot(db, baseRoot)
-
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			baseRoot: &diskLayer{
-				diskdb: db,
-				cache:  fastcache.New(500 * 1024),
-				root:   baseRoot,
-			},
-		},
-	}
-	// Test some different seek positions
-	type testcase struct {
-		pos    byte
-		expkey byte
-	}
-	var cases = []testcase{
-		{0xff, 0x55}, // this should exit immediately without checking key
-		{0x01, 0x02},
-		{0xfe, 0xfe},
-		{0xfd, 0xfe},
-		{0x00, 0x00},
-	}
-	for i, tc := range cases {
-		it, err := snaps.AccountIterator(baseRoot, common.Hash{tc.pos})
-		if err != nil {
-			t.Fatalf("case %d, error: %v", i, err)
-		}
-		count := 0
-		for it.Next() {
-			k, v, err := it.Hash()[0], it.Account()[0], it.Error()
-			if err != nil {
-				t.Fatalf("test %d, item %d, error: %v", i, count, err)
-			}
-			// First item in iterator should have the expected key
-			if count == 0 && k != tc.expkey {
-				t.Fatalf("test %d, item %d, got %v exp %v", i, count, k, tc.expkey)
-			}
-			count++
-			if v != k {
-				t.Fatalf("test %d, item %d, value wrong, got %v exp %v", i, count, v, k)
-			}
-		}
-	}
-}
diff --git a/core/state/snapshot/iterator_test.go b/core/state/snapshot/iterator_test.go
deleted file mode 100644
index ef4859c..0000000
--- a/core/state/snapshot/iterator_test.go
+++ /dev/null
@@ -1,1046 +0,0 @@
-// Copyright 2019 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package snapshot
-
-import (
-	"bytes"
-	"encoding/binary"
-	"fmt"
-	"math/rand"
-	"testing"
-
-	"github.com/VictoriaMetrics/fastcache"
-	"github.com/ava-labs/coreth/core/rawdb"
-	"github.com/ethereum/go-ethereum/common"
-)
-
-// TestAccountIteratorBasics tests some simple single-layer(diff and disk) iteration
-func TestAccountIteratorBasics(t *testing.T) {
-	var (
-		destructs = make(map[common.Hash]struct{})
-		accounts  = make(map[common.Hash][]byte)
-		storage   = make(map[common.Hash]map[common.Hash][]byte)
-	)
-	// Fill up a parent
-	for i := 0; i < 100; i++ {
-		h := randomHash()
-		data := randomAccount()
-
-		accounts[h] = data
-		if rand.Intn(4) == 0 {
-			destructs[h] = struct{}{}
-		}
-		if rand.Intn(2) == 0 {
-			accStorage := make(map[common.Hash][]byte)
-			value := make([]byte, 32)
-			rand.Read(value)
-			accStorage[randomHash()] = value
-			storage[h] = accStorage
-		}
-	}
-	// Add some (identical) layers on top
-	diffLayer := newDiffLayer(emptyLayer(), common.Hash{}, copyDestructs(destructs), copyAccounts(accounts), copyStorage(storage))
-	it := diffLayer.AccountIterator(common.Hash{})
-	verifyIterator(t, 100, it, verifyNothing) // Nil is allowed for single layer iterator
-
-	diskLayer := diffToDisk(diffLayer)
-	it = diskLayer.AccountIterator(common.Hash{})
-	verifyIterator(t, 100, it, verifyNothing) // Nil is allowed for single layer iterator
-}
-
-// TestStorageIteratorBasics tests some simple single-layer(diff and disk) iteration for storage
-func TestStorageIteratorBasics(t *testing.T) {
-	var (
-		nilStorage = make(map[common.Hash]int)
-		accounts   = make(map[common.Hash][]byte)
-		storage    = make(map[common.Hash]map[common.Hash][]byte)
-	)
-	// Fill some random data
-	for i := 0; i < 10; i++ {
-		h := randomHash()
-		accounts[h] = randomAccount()
-
-		accStorage := make(map[common.Hash][]byte)
-		value := make([]byte, 32)
-
-		var nilstorage int
-		for i := 0; i < 100; i++ {
-			rand.Read(value)
-			if rand.Intn(2) == 0 {
-				accStorage[randomHash()] = common.CopyBytes(value)
-			} else {
-				accStorage[randomHash()] = nil // delete slot
-				nilstorage += 1
-			}
-		}
-		storage[h] = accStorage
-		nilStorage[h] = nilstorage
-	}
-	// Add some (identical) layers on top
-	diffLayer := newDiffLayer(emptyLayer(), common.Hash{}, nil, copyAccounts(accounts), copyStorage(storage))
-	for account := range accounts {
-		it, _ := diffLayer.StorageIterator(account, common.Hash{})
-		verifyIterator(t, 100, it, verifyNothing) // Nil is allowed for single layer iterator
-	}
-
-	diskLayer := diffToDisk(diffLayer)
-	for account := range accounts {
-		it, _ := diskLayer.StorageIterator(account, common.Hash{})
-		verifyIterator(t, 100-nilStorage[account], it, verifyNothing) // Nil is allowed for single layer iterator
-	}
-}
-
-type testIterator struct {
-	values []byte
-}
-
-func newTestIterator(values ...byte) *testIterator {
-	return &testIterator{values}
-}
-
-func (ti *testIterator) Seek(common.Hash) {
-	panic("implement me")
-}
-
-func (ti *testIterator) Next() bool {
-	ti.values = ti.values[1:]
-	return len(ti.values) > 0
-}
-
-func (ti *testIterator) Error() error {
-	return nil
-}
-
-func (ti *testIterator) Hash() common.Hash {
-	return common.BytesToHash([]byte{ti.values[0]})
-}
-
-func (ti *testIterator) Account() []byte {
-	return nil
-}
-
-func (ti *testIterator) Slot() []byte {
-	return nil
-}
-
-func (ti *testIterator) Release() {}
-
-func TestFastIteratorBasics(t *testing.T) {
-	type testCase struct {
-		lists   [][]byte
-		expKeys []byte
-	}
-	for i, tc := range []testCase{
-		{lists: [][]byte{{0, 1, 8}, {1, 2, 8}, {2, 9}, {4},
-			{7, 14, 15}, {9, 13, 15, 16}},
-			expKeys: []byte{0, 1, 2, 4, 7, 8, 9, 13, 14, 15, 16}},
-		{lists: [][]byte{{0, 8}, {1, 2, 8}, {7, 14, 15}, {8, 9},
-			{9, 10}, {10, 13, 15, 16}},
-			expKeys: []byte{0, 1, 2, 7, 8, 9, 10, 13, 14, 15, 16}},
-	} {
-		var iterators []*weightedIterator
-		for i, data := range tc.lists {
-			it := newTestIterator(data...)
-			iterators = append(iterators, &weightedIterator{it, i})
-		}
-		fi := &fastIterator{
-			iterators: iterators,
-			initiated: false,
-		}
-		count := 0
-		for fi.Next() {
-			if got, exp := fi.Hash()[31], tc.expKeys[count]; exp != got {
-				t.Errorf("tc %d, [%d]: got %d exp %d", i, count, got, exp)
-			}
-			count++
-		}
-	}
-}
-
-type verifyContent int
-
-const (
-	verifyNothing verifyContent = iota
-	verifyAccount
-	verifyStorage
-)
-
-func verifyIterator(t *testing.T, expCount int, it Iterator, verify verifyContent) {
-	t.Helper()
-
-	var (
-		count = 0
-		last  = common.Hash{}
-	)
-	for it.Next() {
-		hash := it.Hash()
-		if bytes.Compare(last[:], hash[:]) >= 0 {
-			t.Errorf("wrong order: %x >= %x", last, hash)
-		}
-		count++
-		if verify == verifyAccount && len(it.(AccountIterator).Account()) == 0 {
-			t.Errorf("iterator returned nil-value for hash %x", hash)
-		} else if verify == verifyStorage && len(it.(StorageIterator).Slot()) == 0 {
-			t.Errorf("iterator returned nil-value for hash %x", hash)
-		}
-		last = hash
-	}
-	if count != expCount {
-		t.Errorf("iterator count mismatch: have %d, want %d", count, expCount)
-	}
-	if err := it.Error(); err != nil {
-		t.Errorf("iterator failed: %v", err)
-	}
-}
-
-// TestAccountIteratorTraversal tests some simple multi-layer iteration.
-func TestAccountIteratorTraversal(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Stack three diff layers on top with various overlaps
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
-		randomAccountSet("0xaa", "0xee", "0xff", "0xf0"), nil)
-
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
-		randomAccountSet("0xbb", "0xdd", "0xf0"), nil)
-
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
-		randomAccountSet("0xcc", "0xf0", "0xff"), nil)
-
-	// Verify the single and multi-layer iterators
-	head := snaps.Snapshot(common.HexToHash("0x04"))
-
-	verifyIterator(t, 3, head.(snapshot).AccountIterator(common.Hash{}), verifyNothing)
-	verifyIterator(t, 7, head.(*diffLayer).newBinaryAccountIterator(), verifyAccount)
-
-	it, _ := snaps.AccountIterator(common.HexToHash("0x04"), common.Hash{})
-	verifyIterator(t, 7, it, verifyAccount)
-	it.Release()
-
-	// Test after persist some bottom-most layers into the disk,
-	// the functionalities still work.
-	limit := aggregatorMemoryLimit
-	defer func() {
-		aggregatorMemoryLimit = limit
-	}()
-	aggregatorMemoryLimit = 0 // Force pushing the bottom-most layer into disk
-	snaps.Cap(common.HexToHash("0x04"), 2)
-	verifyIterator(t, 7, head.(*diffLayer).newBinaryAccountIterator(), verifyAccount)
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.Hash{})
-	verifyIterator(t, 7, it, verifyAccount)
-	it.Release()
-}
-
-func TestStorageIteratorTraversal(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Stack three diff layers on top with various overlaps
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x01", "0x02", "0x03"}}, nil))
-
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x04", "0x05", "0x06"}}, nil))
-
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x01", "0x02", "0x03"}}, nil))
-
-	// Verify the single and multi-layer iterators
-	head := snaps.Snapshot(common.HexToHash("0x04"))
-
-	diffIter, _ := head.(snapshot).StorageIterator(common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 3, diffIter, verifyNothing)
-	verifyIterator(t, 6, head.(*diffLayer).newBinaryStorageIterator(common.HexToHash("0xaa")), verifyStorage)
-
-	it, _ := snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 6, it, verifyStorage)
-	it.Release()
-
-	// Test after persist some bottom-most layers into the disk,
-	// the functionalities still work.
-	limit := aggregatorMemoryLimit
-	defer func() {
-		aggregatorMemoryLimit = limit
-	}()
-	aggregatorMemoryLimit = 0 // Force pushing the bottom-most layer into disk
-	snaps.Cap(common.HexToHash("0x04"), 2)
-	verifyIterator(t, 6, head.(*diffLayer).newBinaryStorageIterator(common.HexToHash("0xaa")), verifyStorage)
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 6, it, verifyStorage)
-	it.Release()
-}
-
-// TestAccountIteratorTraversalValues tests some multi-layer iteration, where we
-// also expect the correct values to show up.
-func TestAccountIteratorTraversalValues(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Create a batch of account sets to seed subsequent layers with
-	var (
-		a = make(map[common.Hash][]byte)
-		b = make(map[common.Hash][]byte)
-		c = make(map[common.Hash][]byte)
-		d = make(map[common.Hash][]byte)
-		e = make(map[common.Hash][]byte)
-		f = make(map[common.Hash][]byte)
-		g = make(map[common.Hash][]byte)
-		h = make(map[common.Hash][]byte)
-	)
-	for i := byte(2); i < 0xff; i++ {
-		a[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 0, i))
-		if i > 20 && i%2 == 0 {
-			b[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 1, i))
-		}
-		if i%4 == 0 {
-			c[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 2, i))
-		}
-		if i%7 == 0 {
-			d[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 3, i))
-		}
-		if i%8 == 0 {
-			e[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 4, i))
-		}
-		if i > 50 || i < 85 {
-			f[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 5, i))
-		}
-		if i%64 == 0 {
-			g[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 6, i))
-		}
-		if i%128 == 0 {
-			h[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 7, i))
-		}
-	}
-	// Assemble a stack of snapshots from the account layers
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, a, nil)
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, b, nil)
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil, c, nil)
-	snaps.Update(common.HexToHash("0x05"), common.HexToHash("0x04"), nil, d, nil)
-	snaps.Update(common.HexToHash("0x06"), common.HexToHash("0x05"), nil, e, nil)
-	snaps.Update(common.HexToHash("0x07"), common.HexToHash("0x06"), nil, f, nil)
-	snaps.Update(common.HexToHash("0x08"), common.HexToHash("0x07"), nil, g, nil)
-	snaps.Update(common.HexToHash("0x09"), common.HexToHash("0x08"), nil, h, nil)
-
-	it, _ := snaps.AccountIterator(common.HexToHash("0x09"), common.Hash{})
-	head := snaps.Snapshot(common.HexToHash("0x09"))
-	for it.Next() {
-		hash := it.Hash()
-		want, err := head.AccountRLP(hash)
-		if err != nil {
-			t.Fatalf("failed to retrieve expected account: %v", err)
-		}
-		if have := it.Account(); !bytes.Equal(want, have) {
-			t.Fatalf("hash %x: account mismatch: have %x, want %x", hash, have, want)
-		}
-	}
-	it.Release()
-
-	// Test after persist some bottom-most layers into the disk,
-	// the functionalities still work.
-	limit := aggregatorMemoryLimit
-	defer func() {
-		aggregatorMemoryLimit = limit
-	}()
-	aggregatorMemoryLimit = 0 // Force pushing the bottom-most layer into disk
-	snaps.Cap(common.HexToHash("0x09"), 2)
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x09"), common.Hash{})
-	for it.Next() {
-		hash := it.Hash()
-		want, err := head.AccountRLP(hash)
-		if err != nil {
-			t.Fatalf("failed to retrieve expected account: %v", err)
-		}
-		if have := it.Account(); !bytes.Equal(want, have) {
-			t.Fatalf("hash %x: account mismatch: have %x, want %x", hash, have, want)
-		}
-	}
-	it.Release()
-}
-
-func TestStorageIteratorTraversalValues(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	wrapStorage := func(storage map[common.Hash][]byte) map[common.Hash]map[common.Hash][]byte {
-		return map[common.Hash]map[common.Hash][]byte{
-			common.HexToHash("0xaa"): storage,
-		}
-	}
-	// Create a batch of storage sets to seed subsequent layers with
-	var (
-		a = make(map[common.Hash][]byte)
-		b = make(map[common.Hash][]byte)
-		c = make(map[common.Hash][]byte)
-		d = make(map[common.Hash][]byte)
-		e = make(map[common.Hash][]byte)
-		f = make(map[common.Hash][]byte)
-		g = make(map[common.Hash][]byte)
-		h = make(map[common.Hash][]byte)
-	)
-	for i := byte(2); i < 0xff; i++ {
-		a[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 0, i))
-		if i > 20 && i%2 == 0 {
-			b[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 1, i))
-		}
-		if i%4 == 0 {
-			c[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 2, i))
-		}
-		if i%7 == 0 {
-			d[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 3, i))
-		}
-		if i%8 == 0 {
-			e[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 4, i))
-		}
-		if i > 50 || i < 85 {
-			f[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 5, i))
-		}
-		if i%64 == 0 {
-			g[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 6, i))
-		}
-		if i%128 == 0 {
-			h[common.Hash{i}] = []byte(fmt.Sprintf("layer-%d, key %d", 7, i))
-		}
-	}
-	// Assemble a stack of snapshots from the account layers
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, randomAccountSet("0xaa"), wrapStorage(a))
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, randomAccountSet("0xaa"), wrapStorage(b))
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil, randomAccountSet("0xaa"), wrapStorage(c))
-	snaps.Update(common.HexToHash("0x05"), common.HexToHash("0x04"), nil, randomAccountSet("0xaa"), wrapStorage(d))
-	snaps.Update(common.HexToHash("0x06"), common.HexToHash("0x05"), nil, randomAccountSet("0xaa"), wrapStorage(e))
-	snaps.Update(common.HexToHash("0x07"), common.HexToHash("0x06"), nil, randomAccountSet("0xaa"), wrapStorage(e))
-	snaps.Update(common.HexToHash("0x08"), common.HexToHash("0x07"), nil, randomAccountSet("0xaa"), wrapStorage(g))
-	snaps.Update(common.HexToHash("0x09"), common.HexToHash("0x08"), nil, randomAccountSet("0xaa"), wrapStorage(h))
-
-	it, _ := snaps.StorageIterator(common.HexToHash("0x09"), common.HexToHash("0xaa"), common.Hash{})
-	head := snaps.Snapshot(common.HexToHash("0x09"))
-	for it.Next() {
-		hash := it.Hash()
-		want, err := head.Storage(common.HexToHash("0xaa"), hash)
-		if err != nil {
-			t.Fatalf("failed to retrieve expected storage slot: %v", err)
-		}
-		if have := it.Slot(); !bytes.Equal(want, have) {
-			t.Fatalf("hash %x: slot mismatch: have %x, want %x", hash, have, want)
-		}
-	}
-	it.Release()
-
-	// Test after persist some bottom-most layers into the disk,
-	// the functionalities still work.
-	limit := aggregatorMemoryLimit
-	defer func() {
-		aggregatorMemoryLimit = limit
-	}()
-	aggregatorMemoryLimit = 0 // Force pushing the bottom-most layer into disk
-	snaps.Cap(common.HexToHash("0x09"), 2)
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x09"), common.HexToHash("0xaa"), common.Hash{})
-	for it.Next() {
-		hash := it.Hash()
-		want, err := head.Storage(common.HexToHash("0xaa"), hash)
-		if err != nil {
-			t.Fatalf("failed to retrieve expected slot: %v", err)
-		}
-		if have := it.Slot(); !bytes.Equal(want, have) {
-			t.Fatalf("hash %x: slot mismatch: have %x, want %x", hash, have, want)
-		}
-	}
-	it.Release()
-}
-
-// This testcase is notorious, all layers contain the exact same 200 accounts.
-func TestAccountIteratorLargeTraversal(t *testing.T) {
-	// Create a custom account factory to recreate the same addresses
-	makeAccounts := func(num int) map[common.Hash][]byte {
-		accounts := make(map[common.Hash][]byte)
-		for i := 0; i < num; i++ {
-			h := common.Hash{}
-			binary.BigEndian.PutUint64(h[:], uint64(i+1))
-			accounts[h] = randomAccount()
-		}
-		return accounts
-	}
-	// Build up a large stack of snapshots
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	for i := 1; i < 128; i++ {
-		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), nil, makeAccounts(200), nil)
-	}
-	// Iterate the entire stack and ensure everything is hit only once
-	head := snaps.Snapshot(common.HexToHash("0x80"))
-	verifyIterator(t, 200, head.(snapshot).AccountIterator(common.Hash{}), verifyNothing)
-	verifyIterator(t, 200, head.(*diffLayer).newBinaryAccountIterator(), verifyAccount)
-
-	it, _ := snaps.AccountIterator(common.HexToHash("0x80"), common.Hash{})
-	verifyIterator(t, 200, it, verifyAccount)
-	it.Release()
-
-	// Test after persist some bottom-most layers into the disk,
-	// the functionalities still work.
-	limit := aggregatorMemoryLimit
-	defer func() {
-		aggregatorMemoryLimit = limit
-	}()
-	aggregatorMemoryLimit = 0 // Force pushing the bottom-most layer into disk
-	snaps.Cap(common.HexToHash("0x80"), 2)
-
-	verifyIterator(t, 200, head.(*diffLayer).newBinaryAccountIterator(), verifyAccount)
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x80"), common.Hash{})
-	verifyIterator(t, 200, it, verifyAccount)
-	it.Release()
-}
-
-// TestAccountIteratorFlattening tests what happens when we
-// - have a live iterator on child C (parent C1 -> C2 .. CN)
-// - flattens C2 all the way into CN
-// - continues iterating
-func TestAccountIteratorFlattening(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Create a stack of diffs on top
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
-		randomAccountSet("0xaa", "0xee", "0xff", "0xf0"), nil)
-
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
-		randomAccountSet("0xbb", "0xdd", "0xf0"), nil)
-
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
-		randomAccountSet("0xcc", "0xf0", "0xff"), nil)
-
-	// Create an iterator and flatten the data from underneath it
-	it, _ := snaps.AccountIterator(common.HexToHash("0x04"), common.Hash{})
-	defer it.Release()
-
-	if err := snaps.Cap(common.HexToHash("0x04"), 1); err != nil {
-		t.Fatalf("failed to flatten snapshot stack: %v", err)
-	}
-	//verifyIterator(t, 7, it)
-}
-
-func TestAccountIteratorSeek(t *testing.T) {
-	// Create a snapshot stack with some initial data
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
-		randomAccountSet("0xaa", "0xee", "0xff", "0xf0"), nil)
-
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
-		randomAccountSet("0xbb", "0xdd", "0xf0"), nil)
-
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
-		randomAccountSet("0xcc", "0xf0", "0xff"), nil)
-
-	// Account set is now
-	// 02: aa, ee, f0, ff
-	// 03: aa, bb, dd, ee, f0 (, f0), ff
-	// 04: aa, bb, cc, dd, ee, f0 (, f0), ff (, ff)
-	// Construct various iterators and ensure their traversal is correct
-	it, _ := snaps.AccountIterator(common.HexToHash("0x02"), common.HexToHash("0xdd"))
-	defer it.Release()
-	verifyIterator(t, 3, it, verifyAccount) // expected: ee, f0, ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x02"), common.HexToHash("0xaa"))
-	defer it.Release()
-	verifyIterator(t, 4, it, verifyAccount) // expected: aa, ee, f0, ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x02"), common.HexToHash("0xff"))
-	defer it.Release()
-	verifyIterator(t, 1, it, verifyAccount) // expected: ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x02"), common.HexToHash("0xff1"))
-	defer it.Release()
-	verifyIterator(t, 0, it, verifyAccount) // expected: nothing
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.HexToHash("0xbb"))
-	defer it.Release()
-	verifyIterator(t, 6, it, verifyAccount) // expected: bb, cc, dd, ee, f0, ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.HexToHash("0xef"))
-	defer it.Release()
-	verifyIterator(t, 2, it, verifyAccount) // expected: f0, ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.HexToHash("0xf0"))
-	defer it.Release()
-	verifyIterator(t, 2, it, verifyAccount) // expected: f0, ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.HexToHash("0xff"))
-	defer it.Release()
-	verifyIterator(t, 1, it, verifyAccount) // expected: ff
-
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.HexToHash("0xff1"))
-	defer it.Release()
-	verifyIterator(t, 0, it, verifyAccount) // expected: nothing
-}
-
-func TestStorageIteratorSeek(t *testing.T) {
-	// Create a snapshot stack with some initial data
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Stack three diff layers on top with various overlaps
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x01", "0x03", "0x05"}}, nil))
-
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x02", "0x05", "0x06"}}, nil))
-
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x01", "0x05", "0x08"}}, nil))
-
-	// Account set is now
-	// 02: 01, 03, 05
-	// 03: 01, 02, 03, 05 (, 05), 06
-	// 04: 01(, 01), 02, 03, 05(, 05, 05), 06, 08
-	// Construct various iterators and ensure their traversal is correct
-	it, _ := snaps.StorageIterator(common.HexToHash("0x02"), common.HexToHash("0xaa"), common.HexToHash("0x01"))
-	defer it.Release()
-	verifyIterator(t, 3, it, verifyStorage) // expected: 01, 03, 05
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x02"), common.HexToHash("0xaa"), common.HexToHash("0x02"))
-	defer it.Release()
-	verifyIterator(t, 2, it, verifyStorage) // expected: 03, 05
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x02"), common.HexToHash("0xaa"), common.HexToHash("0x5"))
-	defer it.Release()
-	verifyIterator(t, 1, it, verifyStorage) // expected: 05
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x02"), common.HexToHash("0xaa"), common.HexToHash("0x6"))
-	defer it.Release()
-	verifyIterator(t, 0, it, verifyStorage) // expected: nothing
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.HexToHash("0x01"))
-	defer it.Release()
-	verifyIterator(t, 6, it, verifyStorage) // expected: 01, 02, 03, 05, 06, 08
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.HexToHash("0x05"))
-	defer it.Release()
-	verifyIterator(t, 3, it, verifyStorage) // expected: 05, 06, 08
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.HexToHash("0x08"))
-	defer it.Release()
-	verifyIterator(t, 1, it, verifyStorage) // expected: 08
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.HexToHash("0x09"))
-	defer it.Release()
-	verifyIterator(t, 0, it, verifyStorage) // expected: nothing
-}
-
-// TestAccountIteratorDeletions tests that the iterator behaves correct when there are
-// deleted accounts (where the Account() value is nil). The iterator
-// should not output any accounts or nil-values for those cases.
-func TestAccountIteratorDeletions(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Stack three diff layers on top with various overlaps
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"),
-		nil, randomAccountSet("0x11", "0x22", "0x33"), nil)
-
-	deleted := common.HexToHash("0x22")
-	destructed := map[common.Hash]struct{}{
-		deleted: {},
-	}
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"),
-		destructed, randomAccountSet("0x11", "0x33"), nil)
-
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"),
-		nil, randomAccountSet("0x33", "0x44", "0x55"), nil)
-
-	// The output should be 11,33,44,55
-	it, _ := snaps.AccountIterator(common.HexToHash("0x04"), common.Hash{})
-	// Do a quick check
-	verifyIterator(t, 4, it, verifyAccount)
-	it.Release()
-
-	// And a more detailed verification that we indeed do not see '0x22'
-	it, _ = snaps.AccountIterator(common.HexToHash("0x04"), common.Hash{})
-	defer it.Release()
-	for it.Next() {
-		hash := it.Hash()
-		if it.Account() == nil {
-			t.Errorf("iterator returned nil-value for hash %x", hash)
-		}
-		if hash == deleted {
-			t.Errorf("expected deleted elem %x to not be returned by iterator", deleted)
-		}
-	}
-}
-
-func TestStorageIteratorDeletions(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Stack three diff layers on top with various overlaps
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x01", "0x03", "0x05"}}, nil))
-
-	snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x02", "0x04", "0x06"}}, [][]string{{"0x01", "0x03"}}))
-
-	// The output should be 02,04,05,06
-	it, _ := snaps.StorageIterator(common.HexToHash("0x03"), common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 4, it, verifyStorage)
-	it.Release()
-
-	// The output should be 04,05,06
-	it, _ = snaps.StorageIterator(common.HexToHash("0x03"), common.HexToHash("0xaa"), common.HexToHash("0x03"))
-	verifyIterator(t, 3, it, verifyStorage)
-	it.Release()
-
-	// Destruct the whole storage
-	destructed := map[common.Hash]struct{}{
-		common.HexToHash("0xaa"): {},
-	}
-	snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), destructed, nil, nil)
-
-	it, _ = snaps.StorageIterator(common.HexToHash("0x04"), common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 0, it, verifyStorage)
-	it.Release()
-
-	// Re-insert the slots of the same account
-	snaps.Update(common.HexToHash("0x05"), common.HexToHash("0x04"), nil,
-		randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x07", "0x08", "0x09"}}, nil))
-
-	// The output should be 07,08,09
-	it, _ = snaps.StorageIterator(common.HexToHash("0x05"), common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 3, it, verifyStorage)
-	it.Release()
-
-	// Destruct the whole storage but re-create the account in the same layer
-	snaps.Update(common.HexToHash("0x06"), common.HexToHash("0x05"), destructed, randomAccountSet("0xaa"), randomStorageSet([]string{"0xaa"}, [][]string{{"0x11", "0x12"}}, nil))
-	it, _ = snaps.StorageIterator(common.HexToHash("0x06"), common.HexToHash("0xaa"), common.Hash{})
-	verifyIterator(t, 2, it, verifyStorage) // The output should be 11,12
-	it.Release()
-
-	verifyIterator(t, 2, snaps.Snapshot(common.HexToHash("0x06")).(*diffLayer).newBinaryStorageIterator(common.HexToHash("0xaa")), verifyStorage)
-}
-
-// BenchmarkAccountIteratorTraversal is a bit a bit notorious -- all layers contain the
-// exact same 200 accounts. That means that we need to process 2000 items, but
-// only spit out 200 values eventually.
-//
-// The value-fetching benchmark is easy on the binary iterator, since it never has to reach
-// down at any depth for retrieving the values -- all are on the toppmost layer
-//
-// BenchmarkAccountIteratorTraversal/binary_iterator_keys-6         	    2239	    483674 ns/op
-// BenchmarkAccountIteratorTraversal/binary_iterator_values-6       	    2403	    501810 ns/op
-// BenchmarkAccountIteratorTraversal/fast_iterator_keys-6           	    1923	    677966 ns/op
-// BenchmarkAccountIteratorTraversal/fast_iterator_values-6         	    1741	    649967 ns/op
-func BenchmarkAccountIteratorTraversal(b *testing.B) {
-	// Create a custom account factory to recreate the same addresses
-	makeAccounts := func(num int) map[common.Hash][]byte {
-		accounts := make(map[common.Hash][]byte)
-		for i := 0; i < num; i++ {
-			h := common.Hash{}
-			binary.BigEndian.PutUint64(h[:], uint64(i+1))
-			accounts[h] = randomAccount()
-		}
-		return accounts
-	}
-	// Build up a large stack of snapshots
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	for i := 1; i <= 100; i++ {
-		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), nil, makeAccounts(200), nil)
-	}
-	// We call this once before the benchmark, so the creation of
-	// sorted accountlists are not included in the results.
-	head := snaps.Snapshot(common.HexToHash("0x65"))
-	head.(*diffLayer).newBinaryAccountIterator()
-
-	b.Run("binary iterator keys", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			got := 0
-			it := head.(*diffLayer).newBinaryAccountIterator()
-			for it.Next() {
-				got++
-			}
-			if exp := 200; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-	b.Run("binary iterator values", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			got := 0
-			it := head.(*diffLayer).newBinaryAccountIterator()
-			for it.Next() {
-				got++
-				head.(*diffLayer).accountRLP(it.Hash(), 0)
-			}
-			if exp := 200; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-	b.Run("fast iterator keys", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			it, _ := snaps.AccountIterator(common.HexToHash("0x65"), common.Hash{})
-			defer it.Release()
-
-			got := 0
-			for it.Next() {
-				got++
-			}
-			if exp := 200; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-	b.Run("fast iterator values", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			it, _ := snaps.AccountIterator(common.HexToHash("0x65"), common.Hash{})
-			defer it.Release()
-
-			got := 0
-			for it.Next() {
-				got++
-				it.Account()
-			}
-			if exp := 200; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-}
-
-// BenchmarkAccountIteratorLargeBaselayer is a pretty realistic benchmark, where
-// the baselayer is a lot larger than the upper layer.
-//
-// This is heavy on the binary iterator, which in most cases will have to
-// call recursively 100 times for the majority of the values
-//
-// BenchmarkAccountIteratorLargeBaselayer/binary_iterator_(keys)-6         	     514	   1971999 ns/op
-// BenchmarkAccountIteratorLargeBaselayer/binary_iterator_(values)-6       	      61	  18997492 ns/op
-// BenchmarkAccountIteratorLargeBaselayer/fast_iterator_(keys)-6           	   10000	    114385 ns/op
-// BenchmarkAccountIteratorLargeBaselayer/fast_iterator_(values)-6         	    4047	    296823 ns/op
-func BenchmarkAccountIteratorLargeBaselayer(b *testing.B) {
-	// Create a custom account factory to recreate the same addresses
-	makeAccounts := func(num int) map[common.Hash][]byte {
-		accounts := make(map[common.Hash][]byte)
-		for i := 0; i < num; i++ {
-			h := common.Hash{}
-			binary.BigEndian.PutUint64(h[:], uint64(i+1))
-			accounts[h] = randomAccount()
-		}
-		return accounts
-	}
-	// Build up a large stack of snapshots
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, makeAccounts(2000), nil)
-	for i := 2; i <= 100; i++ {
-		snaps.Update(common.HexToHash(fmt.Sprintf("0x%02x", i+1)), common.HexToHash(fmt.Sprintf("0x%02x", i)), nil, makeAccounts(20), nil)
-	}
-	// We call this once before the benchmark, so the creation of
-	// sorted accountlists are not included in the results.
-	head := snaps.Snapshot(common.HexToHash("0x65"))
-	head.(*diffLayer).newBinaryAccountIterator()
-
-	b.Run("binary iterator (keys)", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			got := 0
-			it := head.(*diffLayer).newBinaryAccountIterator()
-			for it.Next() {
-				got++
-			}
-			if exp := 2000; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-	b.Run("binary iterator (values)", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			got := 0
-			it := head.(*diffLayer).newBinaryAccountIterator()
-			for it.Next() {
-				got++
-				v := it.Hash()
-				head.(*diffLayer).accountRLP(v, 0)
-			}
-			if exp := 2000; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-	b.Run("fast iterator (keys)", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			it, _ := snaps.AccountIterator(common.HexToHash("0x65"), common.Hash{})
-			defer it.Release()
-
-			got := 0
-			for it.Next() {
-				got++
-			}
-			if exp := 2000; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-	b.Run("fast iterator (values)", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
-			it, _ := snaps.AccountIterator(common.HexToHash("0x65"), common.Hash{})
-			defer it.Release()
-
-			got := 0
-			for it.Next() {
-				it.Account()
-				got++
-			}
-			if exp := 2000; got != exp {
-				b.Errorf("iterator len wrong, expected %d, got %d", exp, got)
-			}
-		}
-	})
-}
-
-/*
-func BenchmarkBinaryAccountIteration(b *testing.B) {
-	benchmarkAccountIteration(b, func(snap snapshot) AccountIterator {
-		return snap.(*diffLayer).newBinaryAccountIterator()
-	})
-}
-
-func BenchmarkFastAccountIteration(b *testing.B) {
-	benchmarkAccountIteration(b, newFastAccountIterator)
-}
-
-func benchmarkAccountIteration(b *testing.B, iterator func(snap snapshot) AccountIterator) {
-	// Create a diff stack and randomize the accounts across them
-	layers := make([]map[common.Hash][]byte, 128)
-	for i := 0; i < len(layers); i++ {
-		layers[i] = make(map[common.Hash][]byte)
-	}
-	for i := 0; i < b.N; i++ {
-		depth := rand.Intn(len(layers))
-		layers[depth][randomHash()] = randomAccount()
-	}
-	stack := snapshot(emptyLayer())
-	for _, layer := range layers {
-		stack = stack.Update(common.Hash{}, layer, nil, nil)
-	}
-	// Reset the timers and report all the stats
-	it := iterator(stack)
-
-	b.ResetTimer()
-	b.ReportAllocs()
-
-	for it.Next() {
-	}
-}
-*/
diff --git a/core/state/snapshot/snapshot_test.go b/core/state/snapshot/snapshot_test.go
deleted file mode 100644
index 94e3610..0000000
--- a/core/state/snapshot/snapshot_test.go
+++ /dev/null
@@ -1,371 +0,0 @@
-// Copyright 2019 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package snapshot
-
-import (
-	"fmt"
-	"math/big"
-	"math/rand"
-	"testing"
-
-	"github.com/VictoriaMetrics/fastcache"
-	"github.com/ava-labs/coreth/core/rawdb"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/rlp"
-)
-
-// randomHash generates a random blob of data and returns it as a hash.
-func randomHash() common.Hash {
-	var hash common.Hash
-	if n, err := rand.Read(hash[:]); n != common.HashLength || err != nil {
-		panic(err)
-	}
-	return hash
-}
-
-// randomAccount generates a random account and returns it RLP encoded.
-func randomAccount() []byte {
-	root := randomHash()
-	a := Account{
-		Balance:  big.NewInt(rand.Int63()),
-		Nonce:    rand.Uint64(),
-		Root:     root[:],
-		CodeHash: emptyCode[:],
-	}
-	data, _ := rlp.EncodeToBytes(a)
-	return data
-}
-
-// randomAccountSet generates a set of random accounts with the given strings as
-// the account address hashes.
-func randomAccountSet(hashes ...string) map[common.Hash][]byte {
-	accounts := make(map[common.Hash][]byte)
-	for _, hash := range hashes {
-		accounts[common.HexToHash(hash)] = randomAccount()
-	}
-	return accounts
-}
-
-// randomStorageSet generates a set of random slots with the given strings as
-// the slot addresses.
-func randomStorageSet(accounts []string, hashes [][]string, nilStorage [][]string) map[common.Hash]map[common.Hash][]byte {
-	storages := make(map[common.Hash]map[common.Hash][]byte)
-	for index, account := range accounts {
-		storages[common.HexToHash(account)] = make(map[common.Hash][]byte)
-
-		if index < len(hashes) {
-			hashes := hashes[index]
-			for _, hash := range hashes {
-				storages[common.HexToHash(account)][common.HexToHash(hash)] = randomHash().Bytes()
-			}
-		}
-		if index < len(nilStorage) {
-			nils := nilStorage[index]
-			for _, hash := range nils {
-				storages[common.HexToHash(account)][common.HexToHash(hash)] = nil
-			}
-		}
-	}
-	return storages
-}
-
-// Tests that if a disk layer becomes stale, no active external references will
-// be returned with junk data. This version of the test flattens every diff layer
-// to check internal corner case around the bottom-most memory accumulator.
-func TestDiskLayerExternalInvalidationFullFlatten(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Retrieve a reference to the base and commit a diff on top
-	ref := snaps.Snapshot(base.root)
-
-	accounts := map[common.Hash][]byte{
-		common.HexToHash("0xa1"): randomAccount(),
-	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if n := len(snaps.layers); n != 2 {
-		t.Errorf("pre-cap layer count mismatch: have %d, want %d", n, 2)
-	}
-	// Commit the diff layer onto the disk and ensure it's persisted
-	if err := snaps.Cap(common.HexToHash("0x02"), 0); err != nil {
-		t.Fatalf("failed to merge diff layer onto disk: %v", err)
-	}
-	// Since the base layer was modified, ensure that data retrieval on the external reference fail
-	if acc, err := ref.Account(common.HexToHash("0x01")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned account: %#x (err: %v)", acc, err)
-	}
-	if slot, err := ref.Storage(common.HexToHash("0xa1"), common.HexToHash("0xb1")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned storage slot: %#x (err: %v)", slot, err)
-	}
-	if n := len(snaps.layers); n != 1 {
-		t.Errorf("post-cap layer count mismatch: have %d, want %d", n, 1)
-		fmt.Println(snaps.layers)
-	}
-}
-
-// Tests that if a disk layer becomes stale, no active external references will
-// be returned with junk data. This version of the test retains the bottom diff
-// layer to check the usual mode of operation where the accumulator is retained.
-func TestDiskLayerExternalInvalidationPartialFlatten(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Retrieve a reference to the base and commit two diffs on top
-	ref := snaps.Snapshot(base.root)
-
-	accounts := map[common.Hash][]byte{
-		common.HexToHash("0xa1"): randomAccount(),
-	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if n := len(snaps.layers); n != 3 {
-		t.Errorf("pre-cap layer count mismatch: have %d, want %d", n, 3)
-	}
-	// Commit the diff layer onto the disk and ensure it's persisted
-	defer func(memcap uint64) { aggregatorMemoryLimit = memcap }(aggregatorMemoryLimit)
-	aggregatorMemoryLimit = 0
-
-	if err := snaps.Cap(common.HexToHash("0x03"), 2); err != nil {
-		t.Fatalf("failed to merge diff layer onto disk: %v", err)
-	}
-	// Since the base layer was modified, ensure that data retrievald on the external reference fail
-	if acc, err := ref.Account(common.HexToHash("0x01")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned account: %#x (err: %v)", acc, err)
-	}
-	if slot, err := ref.Storage(common.HexToHash("0xa1"), common.HexToHash("0xb1")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned storage slot: %#x (err: %v)", slot, err)
-	}
-	if n := len(snaps.layers); n != 2 {
-		t.Errorf("post-cap layer count mismatch: have %d, want %d", n, 2)
-		fmt.Println(snaps.layers)
-	}
-}
-
-// Tests that if a diff layer becomes stale, no active external references will
-// be returned with junk data. This version of the test flattens every diff layer
-// to check internal corner case around the bottom-most memory accumulator.
-func TestDiffLayerExternalInvalidationFullFlatten(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Commit two diffs on top and retrieve a reference to the bottommost
-	accounts := map[common.Hash][]byte{
-		common.HexToHash("0xa1"): randomAccount(),
-	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if n := len(snaps.layers); n != 3 {
-		t.Errorf("pre-cap layer count mismatch: have %d, want %d", n, 3)
-	}
-	ref := snaps.Snapshot(common.HexToHash("0x02"))
-
-	// Flatten the diff layer into the bottom accumulator
-	if err := snaps.Cap(common.HexToHash("0x03"), 1); err != nil {
-		t.Fatalf("failed to flatten diff layer into accumulator: %v", err)
-	}
-	// Since the accumulator diff layer was modified, ensure that data retrievald on the external reference fail
-	if acc, err := ref.Account(common.HexToHash("0x01")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned account: %#x (err: %v)", acc, err)
-	}
-	if slot, err := ref.Storage(common.HexToHash("0xa1"), common.HexToHash("0xb1")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned storage slot: %#x (err: %v)", slot, err)
-	}
-	if n := len(snaps.layers); n != 2 {
-		t.Errorf("post-cap layer count mismatch: have %d, want %d", n, 2)
-		fmt.Println(snaps.layers)
-	}
-}
-
-// Tests that if a diff layer becomes stale, no active external references will
-// be returned with junk data. This version of the test retains the bottom diff
-// layer to check the usual mode of operation where the accumulator is retained.
-func TestDiffLayerExternalInvalidationPartialFlatten(t *testing.T) {
-	// Create an empty base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// Commit three diffs on top and retrieve a reference to the bottommost
-	accounts := map[common.Hash][]byte{
-		common.HexToHash("0xa1"): randomAccount(),
-	}
-	if err := snaps.Update(common.HexToHash("0x02"), common.HexToHash("0x01"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if err := snaps.Update(common.HexToHash("0x03"), common.HexToHash("0x02"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if err := snaps.Update(common.HexToHash("0x04"), common.HexToHash("0x03"), nil, accounts, nil); err != nil {
-		t.Fatalf("failed to create a diff layer: %v", err)
-	}
-	if n := len(snaps.layers); n != 4 {
-		t.Errorf("pre-cap layer count mismatch: have %d, want %d", n, 4)
-	}
-	ref := snaps.Snapshot(common.HexToHash("0x02"))
-
-	// Doing a Cap operation with many allowed layers should be a no-op
-	exp := len(snaps.layers)
-	if err := snaps.Cap(common.HexToHash("0x04"), 2000); err != nil {
-		t.Fatalf("failed to flatten diff layer into accumulator: %v", err)
-	}
-	if got := len(snaps.layers); got != exp {
-		t.Errorf("layers modified, got %d exp %d", got, exp)
-	}
-	// Flatten the diff layer into the bottom accumulator
-	if err := snaps.Cap(common.HexToHash("0x04"), 2); err != nil {
-		t.Fatalf("failed to flatten diff layer into accumulator: %v", err)
-	}
-	// Since the accumulator diff layer was modified, ensure that data retrievald on the external reference fail
-	if acc, err := ref.Account(common.HexToHash("0x01")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned account: %#x (err: %v)", acc, err)
-	}
-	if slot, err := ref.Storage(common.HexToHash("0xa1"), common.HexToHash("0xb1")); err != ErrSnapshotStale {
-		t.Errorf("stale reference returned storage slot: %#x (err: %v)", slot, err)
-	}
-	if n := len(snaps.layers); n != 3 {
-		t.Errorf("post-cap layer count mismatch: have %d, want %d", n, 3)
-		fmt.Println(snaps.layers)
-	}
-}
-
-// TestPostCapBasicDataAccess tests some functionality regarding capping/flattening.
-func TestPostCapBasicDataAccess(t *testing.T) {
-	// setAccount is a helper to construct a random account entry and assign it to
-	// an account slot in a snapshot
-	setAccount := func(accKey string) map[common.Hash][]byte {
-		return map[common.Hash][]byte{
-			common.HexToHash(accKey): randomAccount(),
-		}
-	}
-	// Create a starting base layer and a snapshot tree out of it
-	base := &diskLayer{
-		diskdb: rawdb.NewMemoryDatabase(),
-		root:   common.HexToHash("0x01"),
-		cache:  fastcache.New(1024 * 500),
-	}
-	snaps := &Tree{
-		layers: map[common.Hash]snapshot{
-			base.root: base,
-		},
-	}
-	// The lowest difflayer
-	snaps.Update(common.HexToHash("0xa1"), common.HexToHash("0x01"), nil, setAccount("0xa1"), nil)
-	snaps.Update(common.HexToHash("0xa2"), common.HexToHash("0xa1"), nil, setAccount("0xa2"), nil)
-	snaps.Update(common.HexToHash("0xb2"), common.HexToHash("0xa1"), nil, setAccount("0xb2"), nil)
-
-	snaps.Update(common.HexToHash("0xa3"), common.HexToHash("0xa2"), nil, setAccount("0xa3"), nil)
-	snaps.Update(common.HexToHash("0xb3"), common.HexToHash("0xb2"), nil, setAccount("0xb3"), nil)
-
-	// checkExist verifies if an account exiss in a snapshot
-	checkExist := func(layer *diffLayer, key string) error {
-		if data, _ := layer.Account(common.HexToHash(key)); data == nil {
-			return fmt.Errorf("expected %x to exist, got nil", common.HexToHash(key))
-		}
-		return nil
-	}
-	// shouldErr checks that an account access errors as expected
-	shouldErr := func(layer *diffLayer, key string) error {
-		if data, err := layer.Account(common.HexToHash(key)); err == nil {
-			return fmt.Errorf("expected error, got data %x", data)
-		}
-		return nil
-	}
-	// check basics
-	snap := snaps.Snapshot(common.HexToHash("0xb3")).(*diffLayer)
-
-	if err := checkExist(snap, "0xa1"); err != nil {
-		t.Error(err)
-	}
-	if err := checkExist(snap, "0xb2"); err != nil {
-		t.Error(err)
-	}
-	if err := checkExist(snap, "0xb3"); err != nil {
-		t.Error(err)
-	}
-	// Cap to a bad root should fail
-	if err := snaps.Cap(common.HexToHash("0x1337"), 0); err == nil {
-		t.Errorf("expected error, got none")
-	}
-	// Now, merge the a-chain
-	snaps.Cap(common.HexToHash("0xa3"), 0)
-
-	// At this point, a2 got merged into a1. Thus, a1 is now modified, and as a1 is
-	// the parent of b2, b2 should no longer be able to iterate into parent.
-
-	// These should still be accessible
-	if err := checkExist(snap, "0xb2"); err != nil {
-		t.Error(err)
-	}
-	if err := checkExist(snap, "0xb3"); err != nil {
-		t.Error(err)
-	}
-	// But these would need iteration into the modified parent
-	if err := shouldErr(snap, "0xa1"); err != nil {
-		t.Error(err)
-	}
-	if err := shouldErr(snap, "0xa2"); err != nil {
-		t.Error(err)
-	}
-	if err := shouldErr(snap, "0xa3"); err != nil {
-		t.Error(err)
-	}
-	// Now, merge it again, just for fun. It should now error, since a3
-	// is a disk layer
-	if err := snaps.Cap(common.HexToHash("0xa3"), 0); err == nil {
-		t.Error("expected error capping the disk layer, got none")
-	}
-}
diff --git a/core/state/snapshot/wipe_test.go b/core/state/snapshot/wipe_test.go
deleted file mode 100644
index a656982..0000000
--- a/core/state/snapshot/wipe_test.go
+++ /dev/null
@@ -1,124 +0,0 @@
-// Copyright 2019 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package snapshot
-
-import (
-	"math/rand"
-	"testing"
-
-	"github.com/ava-labs/coreth/core/rawdb"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/ethdb/memorydb"
-)
-
-// Tests that given a database with random data content, all parts of a snapshot
-// can be crrectly wiped without touching anything else.
-func TestWipe(t *testing.T) {
-	// Create a database with some random snapshot data
-	db := memorydb.New()
-
-	for i := 0; i < 128; i++ {
-		account := randomHash()
-		rawdb.WriteAccountSnapshot(db, account, randomHash().Bytes())
-		for j := 0; j < 1024; j++ {
-			rawdb.WriteStorageSnapshot(db, account, randomHash(), randomHash().Bytes())
-		}
-	}
-	rawdb.WriteSnapshotRoot(db, randomHash())
-
-	// Add some random non-snapshot data too to make wiping harder
-	for i := 0; i < 65536; i++ {
-		// Generate a key that's the wrong length for a state snapshot item
-		var keysize int
-		for keysize == 0 || keysize == 32 || keysize == 64 {
-			keysize = 8 + rand.Intn(64) // +8 to ensure we will "never" randomize duplicates
-		}
-		// Randomize the suffix, dedup and inject it under the snapshot namespace
-		keysuffix := make([]byte, keysize)
-		rand.Read(keysuffix)
-
-		if rand.Int31n(2) == 0 {
-			db.Put(append(rawdb.SnapshotAccountPrefix, keysuffix...), randomHash().Bytes())
-		} else {
-			db.Put(append(rawdb.SnapshotStoragePrefix, keysuffix...), randomHash().Bytes())
-		}
-	}
-	// Sanity check that all the keys are present
-	var items int
-
-	it := db.NewIterator(rawdb.SnapshotAccountPrefix, nil)
-	defer it.Release()
-
-	for it.Next() {
-		key := it.Key()
-		if len(key) == len(rawdb.SnapshotAccountPrefix)+common.HashLength {
-			items++
-		}
-	}
-	it = db.NewIterator(rawdb.SnapshotStoragePrefix, nil)
-	defer it.Release()
-
-	for it.Next() {
-		key := it.Key()
-		if len(key) == len(rawdb.SnapshotStoragePrefix)+2*common.HashLength {
-			items++
-		}
-	}
-	if items != 128+128*1024 {
-		t.Fatalf("snapshot size mismatch: have %d, want %d", items, 128+128*1024)
-	}
-	if hash := rawdb.ReadSnapshotRoot(db); hash == (common.Hash{}) {
-		t.Errorf("snapshot block marker mismatch: have %#x, want <not-nil>", hash)
-	}
-	// Wipe all snapshot entries from the database
-	<-wipeSnapshot(db, true)
-
-	// Iterate over the database end ensure no snapshot information remains
-	it = db.NewIterator(rawdb.SnapshotAccountPrefix, nil)
-	defer it.Release()
-
-	for it.Next() {
-		key := it.Key()
-		if len(key) == len(rawdb.SnapshotAccountPrefix)+common.HashLength {
-			t.Errorf("snapshot entry remained after wipe: %x", key)
-		}
-	}
-	it = db.NewIterator(rawdb.SnapshotStoragePrefix, nil)
-	defer it.Release()
-
-	for it.Next() {
-		key := it.Key()
-		if len(key) == len(rawdb.SnapshotStoragePrefix)+2*common.HashLength {
-			t.Errorf("snapshot entry remained after wipe: %x", key)
-		}
-	}
-	if hash := rawdb.ReadSnapshotRoot(db); hash != (common.Hash{}) {
-		t.Errorf("snapshot block marker remained after wipe: %#x", hash)
-	}
-	// Iterate over the database and ensure miscellaneous items are present
-	items = 0
-
-	it = db.NewIterator(nil, nil)
-	defer it.Release()
-
-	for it.Next() {
-		items++
-	}
-	if items != 65536 {
-		t.Fatalf("misc item count mismatch: have %d, want %d", items, 65536)
-	}
-}
diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 35ce39f..abfa2aa 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -17,6 +17,7 @@
 package vm
 
 import (
+	"errors"
 	"github.com/ava-labs/coreth/core/types"
 	"github.com/ava-labs/coreth/params"
 	"github.com/ethereum/go-ethereum/common"
@@ -265,7 +266,12 @@ func opBalance(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([
 
 func opBalanceMultiCoin(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([]byte, error) {
 	addr, cid := callContext.stack.pop(), callContext.stack.pop()
-	callContext.stack.push(interpreter.evm.StateDB.GetBalanceMultiCoin(common.BigToAddress(addr), common.BigToHash(cid)))
+	res, err := uint256.FromBig(interpreter.evm.StateDB.GetBalanceMultiCoin(
+		common.BigToAddress(addr.ToBig()), common.BigToHash(cid.ToBig())))
+	if err {
+		return nil, errors.New("balance overflow")
+	}
+	callContext.stack.push(res)
 	return nil, nil
 }
 
@@ -725,7 +731,7 @@ func opCallExpert(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx)
 	// Pop other call parameters.
 	addr, value, cid, value2, inOffset, inSize, retOffset, retSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
 	toAddr := common.Address(addr.Bytes20())
-	coinID := common.BigToHash(cid)
+	coinID := common.BigToHash(cid.ToBig())
 	// Get the arguments from the memory.
 	args := callContext.memory.GetPtr(int64(inOffset.Uint64()), int64(inSize.Uint64()))
 
@@ -875,8 +881,8 @@ func opSuicide(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([
 	return nil, nil
 }
 
-func opEMC(pc *uint64, interpreter *EVMInterpreter, contract *Contract, callContext *callCtx) ([]byte, error) {
-	return nil, interpreter.evm.StateDB.EnableMultiCoin(contract.Address())
+func opEMC(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([]byte, error) {
+	return nil, interpreter.evm.StateDB.EnableMultiCoin(callContext.contract.Address())
 }
 
 // following functions are used by the instruction jump  table
diff --git a/coreth.go b/coreth.go
index 1fe2613..4d0c2ee 100644
--- a/coreth.go
+++ b/coreth.go
@@ -2,7 +2,7 @@ package coreth
 
 import (
 	"crypto/ecdsa"
-	"fmt"
+	//"fmt"
 	"io"
 	"os"
 
@@ -17,7 +17,8 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
-	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/trie"
+	//"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/mattn/go-isatty"
 )
@@ -52,18 +53,18 @@ func NewETHChain(config *eth.Config, nodecfg *node.Config, etherBase *common.Add
 	if nodecfg == nil {
 		nodecfg = &node.Config{}
 	}
-	mux := new(event.TypeMux)
-	ctx, ep, err := node.NewServiceContext(nodecfg, mux)
+	//mux := new(event.TypeMux)
+	node, err := node.New(nodecfg)
 	if err != nil {
 		panic(err)
 	}
-	if ep != "" {
-		log.Info(fmt.Sprintf("temporary keystore = %s", ep))
-	}
+	//if ep != "" {
+	//	log.Info(fmt.Sprintf("temporary keystore = %s", ep))
+	//}
 	cb := new(dummy.ConsensusCallbacks)
 	mcb := new(miner.MinerCallbacks)
 	bcb := new(eth.BackendCallbacks)
-	backend, _ := eth.New(&ctx, config, cb, mcb, bcb, chainDB)
+	backend, _ := eth.New(node, config, cb, mcb, bcb, chainDB)
 	chain := &ETHChain{backend: backend, cb: cb, mcb: mcb, bcb: bcb}
 	if etherBase == nil {
 		etherBase = &BlackholeAddr
@@ -85,7 +86,7 @@ func (self *ETHChain) GenBlock() {
 }
 
 func (self *ETHChain) VerifyBlock(block *types.Block) bool {
-	txnHash := types.DeriveSha(block.Transactions())
+	txnHash := types.DeriveSha(block.Transactions(), new(trie.Trie))
 	uncleHash := types.CalcUncleHash(block.Uncles())
 	ethHeader := block.Header()
 	if txnHash != ethHeader.TxHash || uncleHash != ethHeader.UncleHash {
diff --git a/eth/api.go b/eth/api.go
index 92ac928..ada2a97 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -371,7 +371,7 @@ func (api *PublicDebugAPI) AccountRange(blockNrOrHash rpc.BlockNumberOrHash, sta
 			var block *types.Block
 			if number == rpc.LatestBlockNumber {
 				block = api.eth.blockchain.CurrentBlock()
-			} else if blockNr == rpc.AcceptedBlockNumber {
+			} else if number == rpc.AcceptedBlockNumber {
 				block = api.eth.AcceptedBlock()
 			} else {
 				block = api.eth.blockchain.GetBlockByNumber(uint64(number))
diff --git a/eth/backend.go b/eth/backend.go
index 9222181..b1c29a5 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -41,7 +41,6 @@ import (
 	"github.com/ava-labs/coreth/node"
 	"github.com/ava-labs/coreth/params"
 	"github.com/ava-labs/coreth/rpc"
-	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/bloombits"
@@ -50,6 +49,7 @@ import (
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
@@ -127,7 +127,7 @@ func New(stack *node.Node, config *Config,
 	var err error
 	if chainDb == nil {
 		// Assemble the Ethereum object
-		chainDb, err = ctx.OpenDatabaseWithFreezer("chaindata", config.DatabaseCache, config.DatabaseHandles, config.DatabaseFreezer, "eth/db/chaindata/")
+		chainDb, err = stack.OpenDatabaseWithFreezer("chaindata", config.DatabaseCache, config.DatabaseHandles, config.DatabaseFreezer, "eth/db/chaindata/")
 		if err != nil {
 			return nil, err
 		}
@@ -223,7 +223,7 @@ func New(stack *node.Node, config *Config,
 	}
 	eth.APIBackend.gpo = gasprice.NewOracle(eth.APIBackend, gpoParams)
 
-	eth.dialCandidates, err = eth.setupDiscovery(&stack.Config().P2P)
+	//eth.dialCandidates, err = eth.setupDiscovery(&stack.Config().P2P)
 	if err != nil {
 		return nil, err
 	}
@@ -233,8 +233,8 @@ func New(stack *node.Node, config *Config,
 
 	// Register the backend on the node
 	stack.RegisterAPIs(eth.APIs())
-	stack.RegisterProtocols(eth.Protocols())
-	stack.RegisterLifecycle(eth)
+	//stack.RegisterProtocols(eth.Protocols())
+	//stack.RegisterLifecycle(eth)
 	return eth, nil
 }
 
diff --git a/eth/protocol.go b/eth/protocol.go
index 94260c2..ef5dcde 100644
--- a/eth/protocol.go
+++ b/eth/protocol.go
@@ -22,6 +22,7 @@ import (
 	"math/big"
 
 	"github.com/ava-labs/coreth/core"
+	"github.com/ava-labs/coreth/core/forkid"
 	"github.com/ava-labs/coreth/core/types"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/event"
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 8753c05..9915ad4 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -30,7 +30,6 @@ import (
 	"github.com/ava-labs/coreth/accounts/scwallet"
 	"github.com/ava-labs/coreth/consensus/ethash"
 	"github.com/ava-labs/coreth/core"
-	"github.com/ava-labs/coreth/core/rawdb"
 	"github.com/ava-labs/coreth/core/types"
 	"github.com/ava-labs/coreth/core/vm"
 	"github.com/ava-labs/coreth/params"
diff --git a/internal/ethapi/backend.go b/internal/ethapi/backend.go
index ae4196f..cee6b57 100644
--- a/internal/ethapi/backend.go
+++ b/internal/ethapi/backend.go
@@ -22,6 +22,7 @@ import (
 	"math/big"
 
 	"github.com/ava-labs/coreth/accounts"
+	"github.com/ava-labs/coreth/consensus"
 	"github.com/ava-labs/coreth/core"
 	"github.com/ava-labs/coreth/core/state"
 	"github.com/ava-labs/coreth/core/types"
diff --git a/miner/miner.go b/miner/miner.go
index 57938e1..e8e59a4 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -30,7 +30,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/event"
-	"github.com/ethereum/go-ethereum/log"
 )
 
 // Backend wraps all methods required for mining.
@@ -60,7 +59,7 @@ type Miner struct {
 
 func New(eth Backend, config *Config, chainConfig *params.ChainConfig, mux *event.TypeMux, engine consensus.Engine, isLocalBlock func(block *types.Block) bool, mcb *MinerCallbacks) *Miner {
 	return &Miner{
-		worker: newWorker(config, chainConfig, engine, eth, mux, isLocalBlock, mcb),
+		worker: newWorker(config, chainConfig, engine, eth, mux, isLocalBlock, true, mcb),
 	}
 }
 
diff --git a/node/api.go b/node/api.go
index e74d10b..4589d25 100644
--- a/node/api.go
+++ b/node/api.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	//"strings"
 
+	"github.com/ava-labs/coreth/internal/debug"
 	"github.com/ava-labs/coreth/rpc"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto"
diff --git a/node/node.go b/node/node.go
index c6e4181..3ed89ed 100644
--- a/node/node.go
+++ b/node/node.go
@@ -18,14 +18,13 @@ package node
 
 import (
 	"errors"
+	"os"
 	"path/filepath"
-	"reflect"
 	"strings"
 	"sync"
 
 	"github.com/ava-labs/coreth/accounts"
 	"github.com/ava-labs/coreth/core/rawdb"
-	"github.com/ava-labs/coreth/internal/debug"
 	"github.com/ava-labs/coreth/rpc"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
@@ -48,7 +47,6 @@ type Node struct {
 	state         int               // Tracks state of node lifecycle
 
 	lock          sync.Mutex
-	lifecycles    []Lifecycle // All registered backends, services, and auxiliary services that have a lifecycle
 	rpcAPIs       []rpc.API   // List of APIs currently provided by the node
 	inprocHandler *rpc.Server // In-process RPC request handler to process the API requests
 
@@ -61,6 +59,25 @@ const (
 	closedState
 )
 
+func (n *Node) openDataDir() error {
+	if n.config.DataDir == "" {
+		return nil // ephemeral
+	}
+
+	instdir := filepath.Join(n.config.DataDir, n.config.name())
+	if err := os.MkdirAll(instdir, 0700); err != nil {
+		return err
+	}
+	// Lock the instance directory to prevent concurrent use by another instance as well as
+	// accidental use of the instance directory as a database.
+	release, _, err := fileutil.Flock(filepath.Join(instdir, "LOCK"))
+	if err != nil {
+		return convertFileLockError(err)
+	}
+	n.dirLock = release
+	return nil
+}
+
 // New creates a new P2P node, ready for protocol registration.
 func New(conf *Config) (*Node, error) {
 	// Copy config and resolve the datadir so future changes to the current
@@ -266,3 +283,14 @@ func (n *Node) closeDatabases() (errors []error) {
 	}
 	return errors
 }
+
+// RegisterAPIs registers the APIs a service provides on the node.
+func (n *Node) RegisterAPIs(apis []rpc.API) {
+	n.lock.Lock()
+	defer n.lock.Unlock()
+
+	if n.state != initializingState {
+		panic("can't register APIs on running/stopped node")
+	}
+	n.rpcAPIs = append(n.rpcAPIs, apis...)
+}
diff --git a/rpc/metrics.go b/rpc/metrics.go
new file mode 100644
index 0000000..7fb6fc0
--- /dev/null
+++ b/rpc/metrics.go
@@ -0,0 +1,39 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/metrics"
+)
+
+var (
+	rpcRequestGauge        = metrics.NewRegisteredGauge("rpc/requests", nil)
+	successfulRequestGauge = metrics.NewRegisteredGauge("rpc/success", nil)
+	failedReqeustGauge     = metrics.NewRegisteredGauge("rpc/failure", nil)
+	rpcServingTimer        = metrics.NewRegisteredTimer("rpc/duration/all", nil)
+)
+
+func newRPCServingTimer(method string, valid bool) metrics.Timer {
+	flag := "success"
+	if !valid {
+		flag = "failure"
+	}
+	m := fmt.Sprintf("rpc/duration/%s/%s", method, flag)
+	return metrics.GetOrRegisterTimer(m, nil)
+}