go-ethereum/core/state/statedb.go

// Copyright 2014 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 state provides a caching layer atop the Ethereum state trie.
package state

import (
	"errors"
	"fmt"
	"maps"
	"math/big"
	"slices"
	"sync"
	"sync/atomic"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/state/snapshot"
	"github.com/ethereum/go-ethereum/core/stateless"
	"github.com/ethereum/go-ethereum/core/tracing"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/trie"
	"github.com/ethereum/go-ethereum/trie/trienode"
	"github.com/ethereum/go-ethereum/trie/triestate"
	"github.com/ethereum/go-ethereum/trie/utils"
	"github.com/holiman/uint256"
	"golang.org/x/sync/errgroup"
)

// TriesInMemory represents the number of layers that are kept in RAM.
const TriesInMemory = 128

type mutationType int

const (
	update mutationType = iota
	deletion
)

type mutation struct {
	typ     mutationType
	applied bool
}

func (m *mutation) copy() *mutation {
	return &mutation{typ: m.typ, applied: m.applied}
}

func (m *mutation) isDelete() bool {
	return m.typ == deletion
}

// StateDB structs within the ethereum protocol are used to store anything
// within the merkle trie. StateDBs take care of caching and storing
// nested states. It's the general query interface to retrieve:
//
// * Contracts
// * Accounts
//
// Once the state is committed, tries cached in stateDB (including account
// trie, storage tries) will no longer be functional. A new state instance
// must be created with new root and updated database for accessing post-
// commit states.
type StateDB struct {
	db         Database
	prefetcher *triePrefetcher
	trie       Trie
	logger     *tracing.Hooks
	reader     Reader

	// originalRoot is the pre-state root, before any changes were made.
	// It will be updated when the Commit is called.
	originalRoot common.Hash

	// This map holds 'live' objects, which will get modified while
	// processing a state transition.
	stateObjects map[common.Address]*stateObject

	// This map holds 'deleted' objects. An object with the same address
	// might also occur in the 'stateObjects' map due to account
	// resurrection. The account value is tracked as the original value
	// before the transition. This map is populated at the transaction
	// boundaries.
	stateObjectsDestruct map[common.Address]*stateObject

	// This map tracks the account mutations that occurred during the
	// transition. Uncommitted mutations belonging to the same account
	// can be merged into a single one which is equivalent from database's
	// perspective. This map is populated at the transaction boundaries.
	mutations map[common.Address]*mutation

	// DB error.
	// State objects are used by the consensus core and VM which are
	// unable to deal with database-level errors. Any error that occurs
	// during a database read is memoized here and will eventually be
	// returned by StateDB.Commit. Notably, this error is also shared
	// by all cached state objects in case the database failure occurs
	// when accessing state of accounts.
	dbErr error

	// The refund counter, also used by state transitioning.
	refund uint64

	// The tx context and all occurred logs in the scope of transaction.
	thash   common.Hash
	txIndex int
	logs    map[common.Hash][]*types.Log
	logSize uint

	// Preimages occurred seen by VM in the scope of block.
	preimages map[common.Hash][]byte

	// Per-transaction access list
	accessList   *accessList
	accessEvents *AccessEvents

	// Transient storage
	transientStorage transientStorage

	// Journal of state modifications. This is the backbone of
	// Snapshot and RevertToSnapshot.
	journal *journal

	// State witness if cross validation is needed
	witness *stateless.Witness

	// Measurements gathered during execution for debugging purposes
	AccountReads    time.Duration
	AccountHashes   time.Duration
	AccountUpdates  time.Duration
	AccountCommits  time.Duration
	StorageReads    time.Duration
	StorageUpdates  time.Duration
	StorageCommits  time.Duration
	SnapshotCommits time.Duration
	TrieDBCommits   time.Duration

	AccountLoaded  int          // Number of accounts retrieved from the database during the state transition
	AccountUpdated int          // Number of accounts updated during the state transition
	AccountDeleted int          // Number of accounts deleted during the state transition
	StorageLoaded  int          // Number of storage slots retrieved from the database during the state transition
	StorageUpdated atomic.Int64 // Number of storage slots updated during the state transition
	StorageDeleted atomic.Int64 // Number of storage slots deleted during the state transition
}

// New creates a new state from a given trie.
func New(root common.Hash, db Database) (*StateDB, error) {
	tr, err := db.OpenTrie(root)
	if err != nil {
		return nil, err
	}
	reader, err := db.Reader(root)
	if err != nil {
		return nil, err
	}
	sdb := &StateDB{
		db:                   db,
		trie:                 tr,
		originalRoot:         root,
		reader:               reader,
		stateObjects:         make(map[common.Address]*stateObject),
		stateObjectsDestruct: make(map[common.Address]*stateObject),
		mutations:            make(map[common.Address]*mutation),
		logs:                 make(map[common.Hash][]*types.Log),
		preimages:            make(map[common.Hash][]byte),
		journal:              newJournal(),
		accessList:           newAccessList(),
		transientStorage:     newTransientStorage(),
	}
	if db.TrieDB().IsVerkle() {
		sdb.accessEvents = NewAccessEvents(db.PointCache())
	}
	return sdb, nil
}

// SetLogger sets the logger for account update hooks.
func (s *StateDB) SetLogger(l *tracing.Hooks) {
	s.logger = l
}

// StartPrefetcher initializes a new trie prefetcher to pull in nodes from the
// state trie concurrently while the state is mutated so that when we reach the
// commit phase, most of the needed data is already hot.
func (s *StateDB) StartPrefetcher(namespace string, witness *stateless.Witness) {
	// Terminate any previously running prefetcher
	s.StopPrefetcher()

	// Enable witness collection if requested
	s.witness = witness

	// With the switch to the Proof-of-Stake consensus algorithm, block production
	// rewards are now handled at the consensus layer. Consequently, a block may
	// have no state transitions if it contains no transactions and no withdrawals.
	// In such cases, the account trie won't be scheduled for prefetching, leading
	// to unnecessary error logs.
	//
	// To prevent this, the account trie is always scheduled for prefetching once
	// the prefetcher is constructed. For more details, see:
	// https://github.com/ethereum/go-ethereum/issues/29880
	s.prefetcher = newTriePrefetcher(s.db, s.originalRoot, namespace, witness == nil)
	if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, nil, false); err != nil {
		log.Error("Failed to prefetch account trie", "root", s.originalRoot, "err", err)
	}
}

// StopPrefetcher terminates a running prefetcher and reports any leftover stats
// from the gathered metrics.
func (s *StateDB) StopPrefetcher() {
	if s.prefetcher != nil {
		s.prefetcher.terminate(false)
		s.prefetcher.report()
		s.prefetcher = nil
	}
}

// setError remembers the first non-nil error it is called with.
func (s *StateDB) setError(err error) {
	if s.dbErr == nil {
		s.dbErr = err
	}
}

// Error returns the memorized database failure occurred earlier.
func (s *StateDB) Error() error {
	return s.dbErr
}

func (s *StateDB) AddLog(log *types.Log) {
	s.journal.logChange(s.thash)

	log.TxHash = s.thash
	log.TxIndex = uint(s.txIndex)
	log.Index = s.logSize
	if s.logger != nil && s.logger.OnLog != nil {
		s.logger.OnLog(log)
	}
	s.logs[s.thash] = append(s.logs[s.thash], log)
	s.logSize++
}

// GetLogs returns the logs matching the specified transaction hash, and annotates
// them with the given blockNumber and blockHash.
func (s *StateDB) GetLogs(hash common.Hash, blockNumber uint64, blockHash common.Hash) []*types.Log {
	logs := s.logs[hash]
	for _, l := range logs {
		l.BlockNumber = blockNumber
		l.BlockHash = blockHash
	}
	return logs
}

func (s *StateDB) Logs() []*types.Log {
	var logs []*types.Log
	for _, lgs := range s.logs {
		logs = append(logs, lgs...)
	}
	return logs
}

// AddPreimage records a SHA3 preimage seen by the VM.
func (s *StateDB) AddPreimage(hash common.Hash, preimage []byte) {
	if _, ok := s.preimages[hash]; !ok {
		s.preimages[hash] = slices.Clone(preimage)
	}
}

// Preimages returns a list of SHA3 preimages that have been submitted.
func (s *StateDB) Preimages() map[common.Hash][]byte {
	return s.preimages
}

// AddRefund adds gas to the refund counter
func (s *StateDB) AddRefund(gas uint64) {
	s.journal.refundChange(s.refund)
	s.refund += gas
}

// SubRefund removes gas from the refund counter.
// This method will panic if the refund counter goes below zero
func (s *StateDB) SubRefund(gas uint64) {
	s.journal.refundChange(s.refund)
	if gas > s.refund {
		panic(fmt.Sprintf("Refund counter below zero (gas: %d > refund: %d)", gas, s.refund))
	}
	s.refund -= gas
}

// Exist reports whether the given account address exists in the state.
// Notably this also returns true for self-destructed accounts.
func (s *StateDB) Exist(addr common.Address) bool {
	return s.getStateObject(addr) != nil
}

// Empty returns whether the state object is either non-existent
// or empty according to the EIP161 specification (balance = nonce = code = 0)
func (s *StateDB) Empty(addr common.Address) bool {
	so := s.getStateObject(addr)
	return so == nil || so.empty()
}

// GetBalance retrieves the balance from the given address or 0 if object not found
func (s *StateDB) GetBalance(addr common.Address) *uint256.Int {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.Balance()
	}
	return common.U2560
}

// GetNonce retrieves the nonce from the given address or 0 if object not found
func (s *StateDB) GetNonce(addr common.Address) uint64 {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.Nonce()
	}

	return 0
}

// GetStorageRoot retrieves the storage root from the given address or empty
// if object not found.
func (s *StateDB) GetStorageRoot(addr common.Address) common.Hash {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.Root()
	}
	return common.Hash{}
}

// TxIndex returns the current transaction index set by SetTxContext.
func (s *StateDB) TxIndex() int {
	return s.txIndex
}

func (s *StateDB) GetCode(addr common.Address) []byte {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.Code()
	}
	return nil
}

func (s *StateDB) GetCodeSize(addr common.Address) int {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.CodeSize()
	}
	return 0
}

func (s *StateDB) GetCodeHash(addr common.Address) common.Hash {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return common.BytesToHash(stateObject.CodeHash())
	}
	return common.Hash{}
}

// GetState retrieves the value associated with the specific key.
func (s *StateDB) GetState(addr common.Address, hash common.Hash) common.Hash {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.GetState(hash)
	}
	return common.Hash{}
}

// GetCommittedState retrieves the value associated with the specific key
// without any mutations caused in the current execution.
func (s *StateDB) GetCommittedState(addr common.Address, hash common.Hash) common.Hash {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.GetCommittedState(hash)
	}
	return common.Hash{}
}

// Database retrieves the low level database supporting the lower level trie ops.
func (s *StateDB) Database() Database {
	return s.db
}

func (s *StateDB) HasSelfDestructed(addr common.Address) bool {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.selfDestructed
	}
	return false
}

/*
 * SETTERS
 */

// AddBalance adds amount to the account associated with addr.
func (s *StateDB) AddBalance(addr common.Address, amount *uint256.Int, reason tracing.BalanceChangeReason) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.AddBalance(amount, reason)
	}
}

// SubBalance subtracts amount from the account associated with addr.
func (s *StateDB) SubBalance(addr common.Address, amount *uint256.Int, reason tracing.BalanceChangeReason) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.SubBalance(amount, reason)
	}
}

func (s *StateDB) SetBalance(addr common.Address, amount *uint256.Int, reason tracing.BalanceChangeReason) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.SetBalance(amount, reason)
	}
}

func (s *StateDB) SetNonce(addr common.Address, nonce uint64) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.SetNonce(nonce)
	}
}

func (s *StateDB) SetCode(addr common.Address, code []byte) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.SetCode(crypto.Keccak256Hash(code), code)
	}
}

func (s *StateDB) SetState(addr common.Address, key, value common.Hash) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.SetState(key, value)
	}
}

// SetStorage replaces the entire storage for the specified account with given
// storage. This function should only be used for debugging and the mutations
// must be discarded afterwards.
func (s *StateDB) SetStorage(addr common.Address, storage map[common.Hash]common.Hash) {
	// SetStorage needs to wipe the existing storage. We achieve this by marking
	// the account as self-destructed in this block. The effect is that storage
	// lookups will not hit the disk, as it is assumed that the disk data belongs
	// to a previous incarnation of the object.
	//
	// TODO (rjl493456442): This function should only be supported by 'unwritable'
	// state, and all mutations made should be discarded afterward.
	obj := s.getStateObject(addr)
	if obj != nil {
		if _, ok := s.stateObjectsDestruct[addr]; !ok {
			s.stateObjectsDestruct[addr] = obj
		}
	}
	newObj := s.createObject(addr)
	for k, v := range storage {
		newObj.SetState(k, v)
	}
	// Inherit the metadata of original object if it was existent
	if obj != nil {
		newObj.SetCode(common.BytesToHash(obj.CodeHash()), obj.code)
		newObj.SetNonce(obj.Nonce())
		newObj.SetBalance(obj.Balance(), tracing.BalanceChangeUnspecified)
	}
}

// SelfDestruct marks the given account as selfdestructed.
// This clears the account balance.
//
// The account's state object is still available until the state is committed,
// getStateObject will return a non-nil account after SelfDestruct.
func (s *StateDB) SelfDestruct(addr common.Address) {
	stateObject := s.getStateObject(addr)
	if stateObject == nil {
		return
	}
	// Regardless of whether it is already destructed or not, we do have to
	// journal the balance-change, if we set it to zero here.
	if !stateObject.Balance().IsZero() {
		stateObject.SetBalance(new(uint256.Int), tracing.BalanceDecreaseSelfdestruct)
	}
	// If it is already marked as self-destructed, we do not need to add it
	// for journalling a second time.
	if !stateObject.selfDestructed {
		s.journal.destruct(addr)
		stateObject.markSelfdestructed()
	}
}

func (s *StateDB) Selfdestruct6780(addr common.Address) {
	stateObject := s.getStateObject(addr)
	if stateObject == nil {
		return
	}
	if stateObject.newContract {
		s.SelfDestruct(addr)
	}
}

// SetTransientState sets transient storage for a given account. It
// adds the change to the journal so that it can be rolled back
// to its previous value if there is a revert.
func (s *StateDB) SetTransientState(addr common.Address, key, value common.Hash) {
	prev := s.GetTransientState(addr, key)
	if prev == value {
		return
	}
	s.journal.transientStateChange(addr, key, prev)
	s.setTransientState(addr, key, value)
}

// setTransientState is a lower level setter for transient storage. It
// is called during a revert to prevent modifications to the journal.
func (s *StateDB) setTransientState(addr common.Address, key, value common.Hash) {
	s.transientStorage.Set(addr, key, value)
}

// GetTransientState gets transient storage for a given account.
func (s *StateDB) GetTransientState(addr common.Address, key common.Hash) common.Hash {
	return s.transientStorage.Get(addr, key)
}

//
// Setting, updating & deleting state object methods.
//

// updateStateObject writes the given object to the trie.
func (s *StateDB) updateStateObject(obj *stateObject) {
	// Encode the account and update the account trie
	addr := obj.Address()
	if err := s.trie.UpdateAccount(addr, &obj.data, len(obj.code)); err != nil {
		s.setError(fmt.Errorf("updateStateObject (%x) error: %v", addr[:], err))
	}
	if obj.dirtyCode {
		s.trie.UpdateContractCode(obj.Address(), common.BytesToHash(obj.CodeHash()), obj.code)
	}
}

// deleteStateObject removes the given object from the state trie.
func (s *StateDB) deleteStateObject(addr common.Address) {
	if err := s.trie.DeleteAccount(addr); err != nil {
		s.setError(fmt.Errorf("deleteStateObject (%x) error: %v", addr[:], err))
	}
}

// getStateObject retrieves a state object given by the address, returning nil if
// the object is not found or was deleted in this execution context.
func (s *StateDB) getStateObject(addr common.Address) *stateObject {
	// Prefer live objects if any is available
	if obj := s.stateObjects[addr]; obj != nil {
		return obj
	}
	// Short circuit if the account is already destructed in this block.
	if _, ok := s.stateObjectsDestruct[addr]; ok {
		return nil
	}
	s.AccountLoaded++

	start := time.Now()
	acct, err := s.reader.Account(addr)
	if err != nil {
		s.setError(fmt.Errorf("getStateObject (%x) error: %w", addr.Bytes(), err))
		return nil
	}
	s.AccountReads += time.Since(start)

	// Short circuit if the account is not found
	if acct == nil {
		return nil
	}
	// Schedule the resolved account for prefetching if it's enabled.
	if s.prefetcher != nil {
		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, [][]byte{addr[:]}, true); err != nil {
			log.Error("Failed to prefetch account", "addr", addr, "err", err)
		}
	}
	// Insert into the live set
	obj := newObject(s, addr, acct)
	s.setStateObject(obj)
	s.AccountLoaded++
	return obj
}

func (s *StateDB) setStateObject(object *stateObject) {
	s.stateObjects[object.Address()] = object
}

// getOrNewStateObject retrieves a state object or create a new state object if nil.
func (s *StateDB) getOrNewStateObject(addr common.Address) *stateObject {
	obj := s.getStateObject(addr)
	if obj == nil {
		obj = s.createObject(addr)
	}
	return obj
}

// createObject creates a new state object. The assumption is held there is no
// existing account with the given address, otherwise it will be silently overwritten.
func (s *StateDB) createObject(addr common.Address) *stateObject {
	obj := newObject(s, addr, nil)
	s.journal.createObject(addr)
	s.setStateObject(obj)
	return obj
}

// CreateAccount explicitly creates a new state object, assuming that the
// account did not previously exist in the state. If the account already
// exists, this function will silently overwrite it which might lead to a
// consensus bug eventually.
func (s *StateDB) CreateAccount(addr common.Address) {
	s.createObject(addr)
}

// CreateContract is used whenever a contract is created. This may be preceded
// by CreateAccount, but that is not required if it already existed in the
// state due to funds sent beforehand.
// This operation sets the 'newContract'-flag, which is required in order to
// correctly handle EIP-6780 'delete-in-same-transaction' logic.
func (s *StateDB) CreateContract(addr common.Address) {
	obj := s.getStateObject(addr)
	if !obj.newContract {
		obj.newContract = true
		s.journal.createContract(addr)
	}
}

// Copy creates a deep, independent copy of the state.
// Snapshots of the copied state cannot be applied to the copy.
func (s *StateDB) Copy() *StateDB {
	// Copy all the basic fields, initialize the memory ones
	state := &StateDB{
		db:                   s.db,
		trie:                 mustCopyTrie(s.trie),
		reader:               s.reader.Copy(),
		originalRoot:         s.originalRoot,
		stateObjects:         make(map[common.Address]*stateObject, len(s.stateObjects)),
		stateObjectsDestruct: make(map[common.Address]*stateObject, len(s.stateObjectsDestruct)),
		mutations:            make(map[common.Address]*mutation, len(s.mutations)),
		dbErr:                s.dbErr,
		refund:               s.refund,
		thash:                s.thash,
		txIndex:              s.txIndex,
		logs:                 make(map[common.Hash][]*types.Log, len(s.logs)),
		logSize:              s.logSize,
		preimages:            maps.Clone(s.preimages),

		// Do we need to copy the access list and transient storage?
		// In practice: No. At the start of a transaction, these two lists are empty.
		// In practice, we only ever copy state _between_ transactions/blocks, never
		// in the middle of a transaction. However, it doesn't cost us much to copy
		// empty lists, so we do it anyway to not blow up if we ever decide copy them
		// in the middle of a transaction.
		accessList:       s.accessList.Copy(),
		transientStorage: s.transientStorage.Copy(),
		journal:          s.journal.copy(),
	}
	if s.witness != nil {
		state.witness = s.witness.Copy()
	}
	if s.accessEvents != nil {
		state.accessEvents = s.accessEvents.Copy()
	}
	// Deep copy cached state objects.
	for addr, obj := range s.stateObjects {
		state.stateObjects[addr] = obj.deepCopy(state)
	}
	// Deep copy destructed state objects.
	for addr, obj := range s.stateObjectsDestruct {
		state.stateObjectsDestruct[addr] = obj.deepCopy(state)
	}
	// Deep copy the object state markers.
	for addr, op := range s.mutations {
		state.mutations[addr] = op.copy()
	}
	// Deep copy the logs occurred in the scope of block
	for hash, logs := range s.logs {
		cpy := make([]*types.Log, len(logs))
		for i, l := range logs {
			cpy[i] = new(types.Log)
			*cpy[i] = *l
		}
		state.logs[hash] = cpy
	}
	return state
}

// CHANGE(taiko): RevisionId returns the latest snapshot id.
func (s *StateDB) RevisionId() int {
	return s.journal.nextRevisionId
}

// Snapshot returns an identifier for the current revision of the state.
func (s *StateDB) Snapshot() int {
	return s.journal.snapshot()
}

// RevertToSnapshot reverts all state changes made since the given revision.
func (s *StateDB) RevertToSnapshot(revid int) {
	s.journal.revertToSnapshot(revid, s)
}

// GetRefund returns the current value of the refund counter.
func (s *StateDB) GetRefund() uint64 {
	return s.refund
}

// Finalise finalises the state by removing the destructed objects and clears
// the journal as well as the refunds. Finalise, however, will not push any updates
// into the tries just yet. Only IntermediateRoot or Commit will do that.
func (s *StateDB) Finalise(deleteEmptyObjects bool) {
	addressesToPrefetch := make([][]byte, 0, len(s.journal.dirties))
	for addr := range s.journal.dirties {
		obj, exist := s.stateObjects[addr]
		if !exist {
			// ripeMD is 'touched' at block 1714175, in tx 0x1237f737031e40bcde4a8b7e717b2d15e3ecadfe49bb1bbc71ee9deb09c6fcf2
			// That tx goes out of gas, and although the notion of 'touched' does not exist there, the
			// touch-event will still be recorded in the journal. Since ripeMD is a special snowflake,
			// it will persist in the journal even though the journal is reverted. In this special circumstance,
			// it may exist in `s.journal.dirties` but not in `s.stateObjects`.
			// Thus, we can safely ignore it here
			continue
		}
		if obj.selfDestructed || (deleteEmptyObjects && obj.empty()) {
			delete(s.stateObjects, obj.address)
			s.markDelete(addr)

			// If ether was sent to account post-selfdestruct it is burnt.
			if bal := obj.Balance(); s.logger != nil && s.logger.OnBalanceChange != nil && obj.selfDestructed && bal.Sign() != 0 {
				s.logger.OnBalanceChange(obj.address, bal.ToBig(), new(big.Int), tracing.BalanceDecreaseSelfdestructBurn)
			}
			// We need to maintain account deletions explicitly (will remain
			// set indefinitely). Note only the first occurred self-destruct
			// event is tracked.
			if _, ok := s.stateObjectsDestruct[obj.address]; !ok {
				s.stateObjectsDestruct[obj.address] = obj
			}
		} else {
			obj.finalise()
			s.markUpdate(addr)
		}
		// At this point, also ship the address off to the precacher. The precacher
		// will start loading tries, and when the change is eventually committed,
		// the commit-phase will be a lot faster
		addressesToPrefetch = append(addressesToPrefetch, common.CopyBytes(addr[:])) // Copy needed for closure
	}
	if s.prefetcher != nil && len(addressesToPrefetch) > 0 {
		if err := s.prefetcher.prefetch(common.Hash{}, s.originalRoot, common.Address{}, addressesToPrefetch, false); err != nil {
			log.Error("Failed to prefetch addresses", "addresses", len(addressesToPrefetch), "err", err)
		}
	}
	// Invalidate journal because reverting across transactions is not allowed.
	s.clearJournalAndRefund()
}

// IntermediateRoot computes the current root hash of the state trie.
// It is called in between transactions to get the root hash that
// goes into transaction receipts.
func (s *StateDB) IntermediateRoot(deleteEmptyObjects bool) common.Hash {
	// Finalise all the dirty storage states and write them into the tries
	s.Finalise(deleteEmptyObjects)

	// If there was a trie prefetcher operating, terminate it async so that the
	// individual storage tries can be updated as soon as the disk load finishes.
	if s.prefetcher != nil {
		s.prefetcher.terminate(true)
		defer func() {
			s.prefetcher.report()
			s.prefetcher = nil // Pre-byzantium, unset any used up prefetcher
		}()
	}
	// Process all storage updates concurrently. The state object update root
	// method will internally call a blocking trie fetch from the prefetcher,
	// so there's no need to explicitly wait for the prefetchers to finish.
	var (
		start   = time.Now()
		workers errgroup.Group
	)
	if s.db.TrieDB().IsVerkle() {
		// Whilst MPT storage tries are independent, Verkle has one single trie
		// for all the accounts and all the storage slots merged together. The
		// former can thus be simply parallelized, but updating the latter will
		// need concurrency support within the trie itself. That's a TODO for a
		// later time.
		workers.SetLimit(1)
	}
	for addr, op := range s.mutations {
		if op.applied || op.isDelete() {
			continue
		}
		obj := s.stateObjects[addr] // closure for the task runner below
		workers.Go(func() error {
			if s.db.TrieDB().IsVerkle() {
				obj.updateTrie()
			} else {
				obj.updateRoot()

				// If witness building is enabled and the state object has a trie,
				// gather the witnesses for its specific storage trie
				if s.witness != nil && obj.trie != nil {
					s.witness.AddState(obj.trie.Witness())
				}
			}
			return nil
		})
	}
	// If witness building is enabled, gather all the read-only accesses.
	// Skip witness collection in Verkle mode, they will be gathered
	// together at the end.
	if s.witness != nil && !s.db.TrieDB().IsVerkle() {
		// Pull in anything that has been accessed before destruction
		for _, obj := range s.stateObjectsDestruct {
			// Skip any objects that haven't touched their storage
			if len(obj.originStorage) == 0 {
				continue
			}
			if trie := obj.getPrefetchedTrie(); trie != nil {
				s.witness.AddState(trie.Witness())
			} else if obj.trie != nil {
				s.witness.AddState(obj.trie.Witness())
			}
		}
		// Pull in only-read and non-destructed trie witnesses
		for _, obj := range s.stateObjects {
			// Skip any objects that have been updated
			if _, ok := s.mutations[obj.address]; ok {
				continue
			}
			// Skip any objects that haven't touched their storage
			if len(obj.originStorage) == 0 {
				continue
			}
			if trie := obj.getPrefetchedTrie(); trie != nil {
				s.witness.AddState(trie.Witness())
			} else if obj.trie != nil {
				s.witness.AddState(obj.trie.Witness())
			}
		}
	}
	workers.Wait()
	s.StorageUpdates += time.Since(start)

	// Now we're about to start to write changes to the trie. The trie is so far
	// _untouched_. We can check with the prefetcher, if it can give us a trie
	// which has the same root, but also has some content loaded into it.
	//
	// Don't check prefetcher if verkle trie has been used. In the context of verkle,
	// only a single trie is used for state hashing. Replacing a non-nil verkle tree
	// here could result in losing uncommitted changes from storage.
	start = time.Now()
	if s.prefetcher != nil {
		if trie := s.prefetcher.trie(common.Hash{}, s.originalRoot); trie == nil {
			log.Error("Failed to retrieve account pre-fetcher trie")
		} else {
			s.trie = trie
		}
	}
	// Perform updates before deletions.  This prevents resolution of unnecessary trie nodes
	// in circumstances similar to the following:
	//
	// Consider nodes `A` and `B` who share the same full node parent `P` and have no other siblings.
	// During the execution of a block:
	// - `A` self-destructs,
	// - `C` is created, and also shares the parent `P`.
	// If the self-destruct is handled first, then `P` would be left with only one child, thus collapsed
	// into a shortnode. This requires `B` to be resolved from disk.
	// Whereas if the created node is handled first, then the collapse is avoided, and `B` is not resolved.
	var (
		usedAddrs    [][]byte
		deletedAddrs []common.Address
	)
	for addr, op := range s.mutations {
		if op.applied {
			continue
		}
		op.applied = true

		if op.isDelete() {
			deletedAddrs = append(deletedAddrs, addr)
		} else {
			s.updateStateObject(s.stateObjects[addr])
			s.AccountUpdated += 1
		}
		usedAddrs = append(usedAddrs, common.CopyBytes(addr[:])) // Copy needed for closure
	}
	for _, deletedAddr := range deletedAddrs {
		s.deleteStateObject(deletedAddr)
		s.AccountDeleted += 1
	}
	s.AccountUpdates += time.Since(start)

	if s.prefetcher != nil {
		s.prefetcher.used(common.Hash{}, s.originalRoot, usedAddrs)
	}
	// Track the amount of time wasted on hashing the account trie
	defer func(start time.Time) { s.AccountHashes += time.Since(start) }(time.Now())

	hash := s.trie.Hash()

	// If witness building is enabled, gather the account trie witness
	if s.witness != nil {
		s.witness.AddState(s.trie.Witness())
	}
	return hash
}

// SetTxContext sets the current transaction hash and index which are
// used when the EVM emits new state logs. It should be invoked before
// transaction execution.
func (s *StateDB) SetTxContext(thash common.Hash, ti int) {
	s.thash = thash
	s.txIndex = ti
}

func (s *StateDB) clearJournalAndRefund() {
	s.journal.reset()
	s.refund = 0
}

// fastDeleteStorage is the function that efficiently deletes the storage trie
// of a specific account. It leverages the associated state snapshot for fast
// storage iteration and constructs trie node deletion markers by creating
// stack trie with iterated slots.
func (s *StateDB) fastDeleteStorage(snaps *snapshot.Tree, addrHash common.Hash, root common.Hash) (map[common.Hash][]byte, *trienode.NodeSet, error) {
	iter, err := snaps.StorageIterator(s.originalRoot, addrHash, common.Hash{})
	if err != nil {
		return nil, nil, err
	}
	defer iter.Release()

	var (
		nodes = trienode.NewNodeSet(addrHash)
		slots = make(map[common.Hash][]byte)
	)
	stack := trie.NewStackTrie(func(path []byte, hash common.Hash, blob []byte) {
		nodes.AddNode(path, trienode.NewDeleted())
	})
	for iter.Next() {
		slot := common.CopyBytes(iter.Slot())
		if err := iter.Error(); err != nil { // error might occur after Slot function
			return nil, nil, err
		}
		slots[iter.Hash()] = slot

		if err := stack.Update(iter.Hash().Bytes(), slot); err != nil {
			return nil, nil, err
		}
	}
	if err := iter.Error(); err != nil { // error might occur during iteration
		return nil, nil, err
	}
	if stack.Hash() != root {
		return nil, nil, fmt.Errorf("snapshot is not matched, exp %x, got %x", root, stack.Hash())
	}
	return slots, nodes, nil
}

// slowDeleteStorage serves as a less-efficient alternative to "fastDeleteStorage,"
// employed when the associated state snapshot is not available. It iterates the
// storage slots along with all internal trie nodes via trie directly.
func (s *StateDB) slowDeleteStorage(addr common.Address, addrHash common.Hash, root common.Hash) (map[common.Hash][]byte, *trienode.NodeSet, error) {
	tr, err := s.db.OpenStorageTrie(s.originalRoot, addr, root, s.trie)
	if err != nil {
		return nil, nil, fmt.Errorf("failed to open storage trie, err: %w", err)
	}
	it, err := tr.NodeIterator(nil)
	if err != nil {
		return nil, nil, fmt.Errorf("failed to open storage iterator, err: %w", err)
	}
	var (
		nodes = trienode.NewNodeSet(addrHash)
		slots = make(map[common.Hash][]byte)
	)
	for it.Next(true) {
		if it.Leaf() {
			slots[common.BytesToHash(it.LeafKey())] = common.CopyBytes(it.LeafBlob())
			continue
		}
		if it.Hash() == (common.Hash{}) {
			continue
		}
		nodes.AddNode(it.Path(), trienode.NewDeleted())
	}
	if err := it.Error(); err != nil {
		return nil, nil, err
	}
	return slots, nodes, nil
}

// deleteStorage is designed to delete the storage trie of a designated account.
// The function will make an attempt to utilize an efficient strategy if the
// associated state snapshot is reachable; otherwise, it will resort to a less
// efficient approach.
func (s *StateDB) deleteStorage(addr common.Address, addrHash common.Hash, root common.Hash) (map[common.Hash][]byte, *trienode.NodeSet, error) {
	var (
		err   error
		slots map[common.Hash][]byte
		nodes *trienode.NodeSet
	)
	// The fast approach can be failed if the snapshot is not fully
	// generated, or it's internally corrupted. Fallback to the slow
	// one just in case.
	snaps := s.db.Snapshot()
	if snaps != nil {
		slots, nodes, err = s.fastDeleteStorage(snaps, addrHash, root)
	}
	if snaps == nil || err != nil {
		slots, nodes, err = s.slowDeleteStorage(addr, addrHash, root)
	}
	if err != nil {
		return nil, nil, err
	}
	return slots, nodes, nil
}

// handleDestruction processes all destruction markers and deletes the account
// and associated storage slots if necessary. There are four potential scenarios
// as following:
//
//	(a) the account was not existent and be marked as destructed
//	(b) the account was not existent and be marked as destructed,
//	    however, it's resurrected later in the same block.
//	(c) the account was existent and be marked as destructed
//	(d) the account was existent and be marked as destructed,
//	    however it's resurrected later in the same block.
//
// In case (a), nothing needs be deleted, nil to nil transition can be ignored.
// In case (b), nothing needs be deleted, nil is used as the original value for
// newly created account and storages
// In case (c), **original** account along with its storages should be deleted,
// with their values be tracked as original value.
// In case (d), **original** account along with its storages should be deleted,
// with their values be tracked as original value.
func (s *StateDB) handleDestruction() (map[common.Hash]*accountDelete, []*trienode.NodeSet, error) {
	var (
		nodes   []*trienode.NodeSet
		buf     = crypto.NewKeccakState()
		deletes = make(map[common.Hash]*accountDelete)
	)
	for addr, prevObj := range s.stateObjectsDestruct {
		prev := prevObj.origin

		// The account was non-existent, and it's marked as destructed in the scope
		// of block. It can be either case (a) or (b) and will be interpreted as
		// null->null state transition.
		// - for (a), skip it without doing anything
		// - for (b), the resurrected account with nil as original will be handled afterwards
		if prev == nil {
			continue
		}
		// The account was existent, it can be either case (c) or (d).
		addrHash := crypto.HashData(buf, addr.Bytes())
		op := &accountDelete{
			address: addr,
			origin:  types.SlimAccountRLP(*prev),
		}
		deletes[addrHash] = op

		// Short circuit if the origin storage was empty.
		if prev.Root == types.EmptyRootHash {
			continue
		}
		// Remove storage slots belonging to the account.
		slots, set, err := s.deleteStorage(addr, addrHash, prev.Root)
		if err != nil {
			return nil, nil, fmt.Errorf("failed to delete storage, err: %w", err)
		}
		op.storagesOrigin = slots

		// Aggregate the associated trie node changes.
		nodes = append(nodes, set)
	}
	return deletes, nodes, nil
}

// GetTrie returns the account trie.
func (s *StateDB) GetTrie() Trie {
	return s.trie
}

// commit gathers the state mutations accumulated along with the associated
// trie changes, resetting all internal flags with the new state as the base.
func (s *StateDB) commit(deleteEmptyObjects bool) (*stateUpdate, error) {
	// Short circuit in case any database failure occurred earlier.
	if s.dbErr != nil {
		return nil, fmt.Errorf("commit aborted due to earlier error: %v", s.dbErr)
	}
	// Finalize any pending changes and merge everything into the tries
	s.IntermediateRoot(deleteEmptyObjects)

	// Short circuit if any error occurs within the IntermediateRoot.
	if s.dbErr != nil {
		return nil, fmt.Errorf("commit aborted due to database error: %v", s.dbErr)
	}
	// Commit objects to the trie, measuring the elapsed time
	var (
		accountTrieNodesUpdated int
		accountTrieNodesDeleted int
		storageTrieNodesUpdated int
		storageTrieNodesDeleted int

		lock    sync.Mutex                                               // protect two maps below
		nodes   = trienode.NewMergedNodeSet()                            // aggregated trie nodes
		updates = make(map[common.Hash]*accountUpdate, len(s.mutations)) // aggregated account updates

		// merge aggregates the dirty trie nodes into the global set.
		//
		// Given that some accounts may be destroyed and then recreated within
		// the same block, it's possible that a node set with the same owner
		// may already exists. In such cases, these two sets are combined, with
		// the later one overwriting the previous one if any nodes are modified
		// or deleted in both sets.
		//
		// merge run concurrently across  all the state objects and account trie.
		merge = func(set *trienode.NodeSet) error {
			if set == nil {
				return nil
			}
			lock.Lock()
			defer lock.Unlock()

			updates, deletes := set.Size()
			if set.Owner == (common.Hash{}) {
				accountTrieNodesUpdated += updates
				accountTrieNodesDeleted += deletes
			} else {
				storageTrieNodesUpdated += updates
				storageTrieNodesDeleted += deletes
			}
			return nodes.Merge(set)
		}
	)
	// Given that some accounts could be destroyed and then recreated within
	// the same block, account deletions must be processed first. This ensures
	// that the storage trie nodes deleted during destruction and recreated
	// during subsequent resurrection can be combined correctly.
	deletes, delNodes, err := s.handleDestruction()
	if err != nil {
		return nil, err
	}
	for _, set := range delNodes {
		if err := merge(set); err != nil {
			return nil, err
		}
	}
	// Handle all state updates afterwards, concurrently to one another to shave
	// off some milliseconds from the commit operation. Also accumulate the code
	// writes to run in parallel with the computations.
	var (
		start   = time.Now()
		root    common.Hash
		workers errgroup.Group
	)
	// Schedule the account trie first since that will be the biggest, so give
	// it the most time to crunch.
	//
	// TODO(karalabe): This account trie commit is *very* heavy. 5-6ms at chain
	// heads, which seems excessive given that it doesn't do hashing, it just
	// shuffles some data. For comparison, the *hashing* at chain head is 2-3ms.
	// We need to investigate what's happening as it seems something's wonky.
	// Obviously it's not an end of the world issue, just something the original
	// code didn't anticipate for.
	workers.Go(func() error {
		// Write the account trie changes, measuring the amount of wasted time
		newroot, set := s.trie.Commit(true)
		root = newroot

		if err := merge(set); err != nil {
			return err
		}
		s.AccountCommits = time.Since(start)
		return nil
	})
	// Schedule each of the storage tries that need to be updated, so they can
	// run concurrently to one another.
	//
	// TODO(karalabe): Experimentally, the account commit takes approximately the
	// same time as all the storage commits combined, so we could maybe only have
	// 2 threads in total. But that kind of depends on the account commit being
	// more expensive than it should be, so let's fix that and revisit this todo.
	for addr, op := range s.mutations {
		if op.isDelete() {
			continue
		}
		// Write any contract code associated with the state object
		obj := s.stateObjects[addr]
		if obj == nil {
			return nil, errors.New("missing state object")
		}
		// Run the storage updates concurrently to one another
		workers.Go(func() error {
			// Write any storage changes in the state object to its storage trie
			update, set, err := obj.commit()
			if err != nil {
				return err
			}
			if err := merge(set); err != nil {
				return err
			}
			lock.Lock()
			updates[obj.addrHash] = update
			s.StorageCommits = time.Since(start) // overwrite with the longest storage commit runtime
			lock.Unlock()
			return nil
		})
	}
	// Wait for everything to finish and update the metrics
	if err := workers.Wait(); err != nil {
		return nil, err
	}
	accountReadMeters.Mark(int64(s.AccountLoaded))
	storageReadMeters.Mark(int64(s.StorageLoaded))
	accountUpdatedMeter.Mark(int64(s.AccountUpdated))
	storageUpdatedMeter.Mark(s.StorageUpdated.Load())
	accountDeletedMeter.Mark(int64(s.AccountDeleted))
	storageDeletedMeter.Mark(s.StorageDeleted.Load())
	accountTrieUpdatedMeter.Mark(int64(accountTrieNodesUpdated))
	accountTrieDeletedMeter.Mark(int64(accountTrieNodesDeleted))
	storageTriesUpdatedMeter.Mark(int64(storageTrieNodesUpdated))
	storageTriesDeletedMeter.Mark(int64(storageTrieNodesDeleted))

	// Clear the metric markers
	s.AccountLoaded, s.AccountUpdated, s.AccountDeleted = 0, 0, 0
	s.StorageLoaded = 0
	s.StorageUpdated.Store(0)
	s.StorageDeleted.Store(0)

	// Clear all internal flags and update state root at the end.
	s.mutations = make(map[common.Address]*mutation)
	s.stateObjectsDestruct = make(map[common.Address]*stateObject)

	origin := s.originalRoot
	s.originalRoot = root
	return newStateUpdate(origin, root, deletes, updates, nodes), nil
}

// commitAndFlush is a wrapper of commit which also commits the state mutations
// to the configured data stores.
func (s *StateDB) commitAndFlush(block uint64, deleteEmptyObjects bool) (*stateUpdate, error) {
	ret, err := s.commit(deleteEmptyObjects)
	if err != nil {
		return nil, err
	}
	// Commit dirty contract code if any exists
	if db := s.db.TrieDB().Disk(); db != nil && len(ret.codes) > 0 {
		batch := db.NewBatch()
		for _, code := range ret.codes {
			rawdb.WriteCode(batch, code.hash, code.blob)
		}
		if err := batch.Write(); err != nil {
			return nil, err
		}
	}
	if !ret.empty() {
		// If snapshotting is enabled, update the snapshot tree with this new version
		if snap := s.db.Snapshot(); snap != nil && snap.Snapshot(ret.originRoot) != nil {
			start := time.Now()
			if err := snap.Update(ret.root, ret.originRoot, ret.destructs, ret.accounts, ret.storages); err != nil {
				log.Warn("Failed to update snapshot tree", "from", ret.originRoot, "to", ret.root, "err", err)
			}
			// Keep 128 diff layers in the memory, persistent layer is 129th.
			// - head layer is paired with HEAD state
			// - head-1 layer is paired with HEAD-1 state
			// - head-127 layer(bottom-most diff layer) is paired with HEAD-127 state
			if err := snap.Cap(ret.root, TriesInMemory); err != nil {
				log.Warn("Failed to cap snapshot tree", "root", ret.root, "layers", TriesInMemory, "err", err)
			}
			s.SnapshotCommits += time.Since(start)
		}
		// If trie database is enabled, commit the state update as a new layer
		if db := s.db.TrieDB(); db != nil {
			start := time.Now()
			set := triestate.New(ret.accountsOrigin, ret.storagesOrigin)
			if err := db.Update(ret.root, ret.originRoot, block, ret.nodes, set); err != nil {
				return nil, err
			}
			s.TrieDBCommits += time.Since(start)
		}
	}
	s.reader, _ = s.db.Reader(s.originalRoot)
	return ret, err
}

// Commit writes the state mutations into the configured data stores.
//
// Once the state is committed, tries cached in stateDB (including account
// trie, storage tries) will no longer be functional. A new state instance
// must be created with new root and updated database for accessing post-
// commit states.
//
// The associated block number of the state transition is also provided
// for more chain context.
func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool) (common.Hash, error) {
	ret, err := s.commitAndFlush(block, deleteEmptyObjects)
	if err != nil {
		return common.Hash{}, err
	}
	return ret.root, nil
}

// Prepare handles the preparatory steps for executing a state transition with.
// This method must be invoked before state transition.
//
// Berlin fork:
// - Add sender to access list (2929)
// - Add destination to access list (2929)
// - Add precompiles to access list (2929)
// - Add the contents of the optional tx access list (2930)
//
// Potential EIPs:
// - Reset access list (Berlin)
// - Add coinbase to access list (EIP-3651)
// - Reset transient storage (EIP-1153)
func (s *StateDB) Prepare(rules params.Rules, sender, coinbase common.Address, dst *common.Address, precompiles []common.Address, list types.AccessList) {
	if rules.IsEIP2929 && rules.IsEIP4762 {
		panic("eip2929 and eip4762 are both activated")
	}
	if rules.IsEIP2929 {
		// Clear out any leftover from previous executions
		al := newAccessList()
		s.accessList = al

		al.AddAddress(sender)
		if dst != nil {
			al.AddAddress(*dst)
			// If it's a create-tx, the destination will be added inside evm.create
		}
		for _, addr := range precompiles {
			al.AddAddress(addr)
		}
		for _, el := range list {
			al.AddAddress(el.Address)
			for _, key := range el.StorageKeys {
				al.AddSlot(el.Address, key)
			}
		}
		if rules.IsShanghai { // EIP-3651: warm coinbase
			al.AddAddress(coinbase)
		}
	}
	// Reset transient storage at the beginning of transaction execution
	s.transientStorage = newTransientStorage()
}

// AddAddressToAccessList adds the given address to the access list
func (s *StateDB) AddAddressToAccessList(addr common.Address) {
	if s.accessList.AddAddress(addr) {
		s.journal.accessListAddAccount(addr)
	}
}

// AddSlotToAccessList adds the given (address, slot)-tuple to the access list
func (s *StateDB) AddSlotToAccessList(addr common.Address, slot common.Hash) {
	addrMod, slotMod := s.accessList.AddSlot(addr, slot)
	if addrMod {
		// In practice, this should not happen, since there is no way to enter the
		// scope of 'address' without having the 'address' become already added
		// to the access list (via call-variant, create, etc).
		// Better safe than sorry, though
		s.journal.accessListAddAccount(addr)
	}
	if slotMod {
		s.journal.accessListAddSlot(addr, slot)
	}
}

// AddressInAccessList returns true if the given address is in the access list.
func (s *StateDB) AddressInAccessList(addr common.Address) bool {
	return s.accessList.ContainsAddress(addr)
}

// SlotInAccessList returns true if the given (address, slot)-tuple is in the access list.
func (s *StateDB) SlotInAccessList(addr common.Address, slot common.Hash) (addressPresent bool, slotPresent bool) {
	return s.accessList.Contains(addr, slot)
}

// markDelete is invoked when an account is deleted but the deletion is
// not yet committed. The pending mutation is cached and will be applied
// all together
func (s *StateDB) markDelete(addr common.Address) {
	if _, ok := s.mutations[addr]; !ok {
		s.mutations[addr] = &mutation{}
	}
	s.mutations[addr].applied = false
	s.mutations[addr].typ = deletion
}

func (s *StateDB) markUpdate(addr common.Address) {
	if _, ok := s.mutations[addr]; !ok {
		s.mutations[addr] = &mutation{}
	}
	s.mutations[addr].applied = false
	s.mutations[addr].typ = update
}

// PointCache returns the point cache used by verkle tree.
func (s *StateDB) PointCache() *utils.PointCache {
	return s.db.PointCache()
}

// Witness retrieves the current state witness being collected.
func (s *StateDB) Witness() *stateless.Witness {
	return s.witness
}

func (s *StateDB) AccessEvents() *AccessEvents {
	return s.accessEvents
}