statedb.go

// Copyright 2018 The go-ethereum Authors
// This file is part of the CortexFoundation library.
//
// The CortexFoundation 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 CortexFoundation 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 CortexFoundation library. If not, see <http://www.gnu.org/licenses/>.

// Package state provides a caching layer atop the Cortex state trie.
package state

import (
	"errors"
	"fmt"
	"math/big"
	"sort"
	"time"

	"github.com/CortexFoundation/CortexTheseus/common"
	"github.com/CortexFoundation/CortexTheseus/core/rawdb"
	"github.com/CortexFoundation/CortexTheseus/core/state/snapshot"
	"github.com/CortexFoundation/CortexTheseus/core/types"
	"github.com/CortexFoundation/CortexTheseus/crypto"
	"github.com/CortexFoundation/CortexTheseus/log"
	"github.com/CortexFoundation/CortexTheseus/metrics"
	"github.com/CortexFoundation/CortexTheseus/rlp"
	"github.com/CortexFoundation/CortexTheseus/trie"
)

type revision struct {
	id           int
	journalIndex int
}

type proofList [][]byte

func (n *proofList) Put(key []byte, value []byte) error {
	*n = append(*n, value)
	return nil
}

func (n *proofList) Delete(key []byte) error {
	panic("not supported")
}

// StateDBs within the cortex 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
type StateDB struct {
	db         Database
	prefetcher *triePrefetcher
	trie       Trie
	hasher     crypto.KeccakState
	snaps      *snapshot.Tree    // Nil if snapshot is not available
	snap       snapshot.Snapshot // Nil if snapshot is not available

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

	// These maps hold the state changes (including the corresponding
	// original value) that occurred in this **block**.
	accounts       map[common.Hash][]byte                    // The mutated accounts in 'slim RLP' encoding
	storages       map[common.Hash]map[common.Hash][]byte    // The mutated slots in prefix-zero trimmed rlp format
	accountsOrigin map[common.Address][]byte                 // The original value of mutated accounts in 'slim RLP' encoding
	storagesOrigin map[common.Address]map[common.Hash][]byte // The original value of mutated slots in prefix-zero trimmed rlp format

	// This map holds 'live' objects, which will get modified while processing a state transition.
	stateObjects         map[common.Address]*stateObject
	stateObjectsPending  map[common.Address]struct{} // State objects finalized but not yet written to the trie
	stateObjectsDirty    map[common.Address]struct{}
	stateObjectsDestruct map[common.Address]*types.StateAccount // State objects destructed in the block along with its previous value

	// 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.
	dbErr error

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

	thash   common.Hash
	txIndex int
	logs    map[common.Hash][]*types.Log
	logSize uint

	preimages map[common.Hash][]byte

	// Per-transaction access list
	accessList *accessList

	// Transient storage
	transientStorage transientStorage

	// Journal of state modifications. This is the backbone of
	// Snapshot and RevertToSnapshot.
	journal        *journal
	validRevisions []revision
	nextRevisionId int

	AccountReads         time.Duration
	AccountHashes        time.Duration
	AccountUpdates       time.Duration
	AccountCommits       time.Duration
	StorageReads         time.Duration
	StorageHashes        time.Duration
	StorageUpdates       time.Duration
	StorageCommits       time.Duration
	SnapshotAccountReads time.Duration
	SnapshotStorageReads time.Duration
	SnapshotCommits      time.Duration
	TrieDBCommits        time.Duration
}

// Create a new state from a given trie.
func New(root common.Hash, db Database, snaps *snapshot.Tree) (*StateDB, error) {
	tr, err := db.OpenTrie(root)
	if err != nil {
		return nil, err
	}
	sdb := &StateDB{
		db:                   db,
		trie:                 tr,
		originalRoot:         root,
		snaps:                snaps,
		accounts:             make(map[common.Hash][]byte),
		storages:             make(map[common.Hash]map[common.Hash][]byte),
		accountsOrigin:       make(map[common.Address][]byte),
		storagesOrigin:       make(map[common.Address]map[common.Hash][]byte),
		stateObjects:         make(map[common.Address]*stateObject),
		stateObjectsPending:  make(map[common.Address]struct{}),
		stateObjectsDirty:    make(map[common.Address]struct{}),
		stateObjectsDestruct: make(map[common.Address]*types.StateAccount),
		logs:                 make(map[common.Hash][]*types.Log),
		preimages:            make(map[common.Hash][]byte),
		journal:              newJournal(),
		accessList:           newAccessList(),
		transientStorage:     newTransientStorage(),
		hasher:               crypto.NewKeccakState(),
	}
	if sdb.snaps != nil {
		sdb.snap = sdb.snaps.Snapshot(root)
	}
	return sdb, nil
}

// 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) {
	if s.prefetcher != nil {
		s.prefetcher.close()
		s.prefetcher = nil
	}
	if s.snap != nil {
		s.prefetcher = newTriePrefetcher(s.db, s.originalRoot, namespace)
	}
}

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

func (s *StateDB) Error() error {
	return s.dbErr
}

func (s *StateDB) AddLog(log *types.Log) {
	s.journal.append(addLogChange{txhash: s.thash})

	log.TxHash = s.thash
	log.TxIndex = uint(s.txIndex)
	log.Index = s.logSize
	s.logs[s.thash] = append(s.logs[s.thash], log)
	s.logSize++
}

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 s.logs[hash]
}

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.journal.append(addPreimageChange{hash: hash})
		pi := make([]byte, len(preimage))
		copy(pi, preimage)
		s.preimages[hash] = pi
	}
}

// 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.append(refundChange{prev: 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.append(refundChange{prev: 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()
}

// Retrieve the balance from the given address or 0 if object not found
func (s *StateDB) GetBalance(addr common.Address) *big.Int {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.Balance()
	}
	return common.Big0
}

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 Prepare.
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 a value from the given account's storage trie
func (s *StateDB) GetState(addr common.Address, bhash common.Hash) common.Hash {
	stateObject := s.getStateObject(addr)
	if stateObject != nil {
		return stateObject.GetState(bhash)
	}
	return common.Hash{}
}

// GetProof returns the MerkleProof for a given Account
func (s *StateDB) GetProof(addr common.Address) ([][]byte, error) {
	return s.GetProofByHash(crypto.Keccak256Hash(addr.Bytes()))
}

// GetProofByHash returns the Merkle proof for a given account.
func (s *StateDB) GetProofByHash(addrHash common.Hash) ([][]byte, error) {
	var proof proofList
	err := s.trie.Prove(addrHash[:], 0, &proof)
	return proof, err
}

// GetProof returns the StorageProof for given key
func (s *StateDB) GetStorageProof(a common.Address, key common.Hash) ([][]byte, error) {
	var proof proofList
	trie := s.StorageTrie(a)
	if trie == nil {
		return proof, errors.New("storage trie for requested address does not exist")
	}
	err := trie.Prove(crypto.Keccak256(key.Bytes()), 0, &proof)
	return proof, err
}

// GetStorageProofByHash returns the Merkle proof for given storage slot.
func (s *StateDB) GetStorageProofByHash(a common.Address, key common.Hash) ([][]byte, error) {
	var proof proofList
	trie := s.StorageTrie(a)
	if trie == nil {
		return proof, errors.New("storage trie for requested address does not exist")
	}
	err := trie.Prove(crypto.Keccak256(key.Bytes()), 0, &proof)
	return proof, err
}

// GetCommittedState retrieves a value from the given account's committed storage trie.
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
}

// StorageTrie returns the storage trie of an account.
// The return value is a copy and is nil for non-existent accounts.
func (s *StateDB) StorageTrie(addr common.Address) Trie {
	stateObject := s.getStateObject(addr)
	if stateObject == nil {
		return nil
	}
	cpy := stateObject.deepCopy(s)
	cpy.updateTrie()
	return cpy.getTrie()
}

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 *big.Int) {
	stateObject := s.getOrNewStateObject(addr)
	if stateObject != nil {
		stateObject.AddBalance(amount)
	}
}

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

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

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.
func (s *StateDB) SetStorage(addr common.Address, storage map[common.Hash]common.Hash) {
	// SetStorage needs to wipe existing storage. We achieve this by pretending
	// that the account self-destructed earlier in this block, by flagging
	// it in stateObjectsDestruct. The effect of doing so is that storage lookups
	// will not hit disk, since it is assumed that the disk-data is belonging
	// to a previous incarnation of the object.
	// state and all mutations made should all be discarded afterwards.
	if _, ok := s.stateObjectsDestruct[addr]; !ok {
		s.stateObjectsDestruct[addr] = nil
	}
	stateObject := s.getOrNewStateObject(addr)
	for k, v := range storage {
		stateObject.SetState(k, v)
	}
}

// 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
	}
	s.journal.append(selfDestructChange{
		account:     &addr,
		prev:        stateObject.selfDestructed,
		prevbalance: new(big.Int).Set(stateObject.Balance()),
		prevupload:  new(big.Int).Set(stateObject.Upload()),
		prevnum:     new(big.Int).Set(stateObject.Num()),
	})
	stateObject.markSelfdestructed()
	stateObject.data.Balance = new(big.Int)
	stateObject.data.Upload = new(big.Int)
	stateObject.data.Num = new(big.Int)
}

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

	if stateObject.created {
		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.append(transientStorageChange{
		account:  &addr,
		key:      key,
		prevalue: 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) {
	// Track the amount of time wasted on updating the account from the trie
	if metrics.EnabledExpensive {
		defer func(start time.Time) { s.AccountUpdates += time.Since(start) }(time.Now())
	}
	// Encode the account and update the account trie
	addr := obj.Address()
	if err := s.trie.TryUpdateAccount(addr[:], &obj.data); 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)
	}
	// Cache the data until commit. Note, this update mechanism is not symmetric
	// to the deletion, because whereas it is enough to track account updates
	// at commit time, deletions need tracking at transaction boundary level to
	// ensure we capture state clearing.

	// If state snapshotting is active, cache the data til commit. Note, this
	// update mechanism is not symmetric to the deletion, because whereas it is
	// enough to track account updates at commit time, deletions need tracking
	// at transaction boundary level to ensure we capture state clearing.
	s.accounts[obj.addrHash] = types.SlimAccountRLP(obj.data)
	// Track the original value of mutated account, nil means it was not present.
	// Skip if it has been tracked (because updateStateObject may be called
	// multiple times in a block).
	if _, ok := s.accountsOrigin[obj.address]; !ok {
		if obj.origin == nil {
			s.accountsOrigin[obj.address] = nil
		} else {
			s.accountsOrigin[obj.address] = types.SlimAccountRLP(*obj.origin)
		}
	}
}

// deleteStateObject removes the given object from the state trie.
func (s *StateDB) deleteStateObject(obj *stateObject) {
	// Track the amount of time wasted on deleting the account from the trie
	if metrics.EnabledExpensive {
		defer func(start time.Time) { s.AccountUpdates += time.Since(start) }(time.Now())
	}
	//stateObject.deleted = true
	addr := obj.Address()
	if err := s.trie.TryDeleteAccount(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. If you need
// to differentiate between non-existent/just-deleted, use getDeletedStateObject
func (s *StateDB) getStateObject(addr common.Address) *stateObject {
	if obj := s.getDeletedStateObject(addr); obj != nil && !obj.deleted {
		return obj
	}
	return nil
}

// getDeletedStateObject is similar to getStateObject, but instead of returning
// nil for a deleted state object, it returns the actual object with the deleted
// flag set. This is needed by the state journal to revert to the correct s-
// destructed object instead of wiping all knowledge about the state object.
func (s *StateDB) getDeletedStateObject(addr common.Address) *stateObject {
	// Prefer 'live' objects.
	if obj := s.stateObjects[addr]; obj != nil {
		return obj
	}
	// If no live objects are available, attempt to use snapshots
	var data *types.StateAccount
	if s.snap != nil {
		start := time.Now()
		acc, err := s.snap.Account(crypto.HashData(s.hasher, addr.Bytes()))
		if metrics.EnabledExpensive {
			s.SnapshotAccountReads += time.Since(start)
		}
		if err == nil {
			if acc == nil {
				return nil
			}
			data = &types.StateAccount{
				Nonce:    acc.Nonce,
				Balance:  acc.Balance,
				CodeHash: acc.CodeHash,
				Root:     common.BytesToHash(acc.Root),
				Upload:   acc.Upload,
				Num:      acc.Num,
			}
			if len(data.CodeHash) == 0 {
				data.CodeHash = types.EmptyCodeHash.Bytes()
			}
			if data.Root == (common.Hash{}) {
				data.Root = types.EmptyRootHash
			}
		}
	}
	// If snapshot unavailable or reading from it failed, load from the database
	if data == nil {
		start := time.Now()
		enc, err := s.trie.TryGet(addr.Bytes())
		if metrics.EnabledExpensive {
			s.AccountReads += time.Since(start)
		}
		if err != nil {
			s.setError(fmt.Errorf("getDeleteStateObject (%x) error: %v", addr.Bytes(), err))
			return nil
		}
		if len(enc) == 0 {
			return nil
		}
		data = new(types.StateAccount)
		if err := rlp.DecodeBytes(enc, data); err != nil {
			log.Error("Failed to decode state object", "addr", addr, "err", err)
			return nil
		}
	}
	// Insert into the live set
	obj := newObject(s, addr, data)
	s.setStateObject(obj)
	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 {
	stateObject := s.getStateObject(addr)
	if stateObject == nil { // || stateObject.deleted {
		stateObject, _ = s.createObject(addr)
	}
	return stateObject
}

// createObject creates a new state object. If there is an existing account with
// the given address, it is overwritten and returned as the second return value.
func (s *StateDB) createObject(addr common.Address) (newobj, prev *stateObject) {
	prev = s.getDeletedStateObject(addr) // Note, prev might have been deleted, we need that!
	newobj = newObject(s, addr, nil)
	//newobj.setNonce(0) // sets the object to dirty
	if prev == nil {
		s.journal.append(createObjectChange{account: &addr})
	} else {
		// The original account should be marked as destructed and all cached
		// account and storage data should be cleared as well. Note, it must
		// be done here, otherwise the destruction event of original one will
		// be lost.
		_, prevdestruct := s.stateObjectsDestruct[prev.address]
		if !prevdestruct {
			s.stateObjectsDestruct[prev.address] = prev.origin
		}
		// There may be some cached account/storage data already since IntermediateRoot
		// will be called for each transaction before byzantium fork which will always
		// cache the latest account/storage data.
		prevAccount, ok := s.accountsOrigin[prev.address]
		s.journal.append(resetObjectChange{
			account:                &addr,
			prev:                   prev,
			prevdestruct:           prevdestruct,
			prevAccount:            s.accounts[prev.addrHash],
			prevStorage:            s.storages[prev.addrHash],
			prevAccountOriginExist: ok,
			prevAccountOrigin:      prevAccount,
			prevStorageOrigin:      s.storagesOrigin[prev.address],
		})
		delete(s.accounts, prev.addrHash)
		delete(s.storages, prev.addrHash)
		delete(s.accountsOrigin, prev.address)
		delete(s.storagesOrigin, prev.address)
	}

	s.setStateObject(newobj)
	if prev != nil && !prev.deleted {
		return newobj, prev
	}
	return newobj, nil
}

// CreateAccount explicitly creates a state object. If a state object with the address
// already exists the balance is carried over to the new account.
//
// CreateAccount is called during the CVM CREATE operation. The situation might arise that
// a contract does the following:
//
//  1. sends funds to sha(account ++ (nonce + 1))
//  2. tx_create(sha(account ++ nonce)) (note that this gets the address of 1)
//
// Carrying over the balance ensures that Cortex doesn't disappear.
func (s *StateDB) CreateAccount(addr common.Address) {
	newObj, prev := s.createObject(addr)
	if prev != nil {
		newObj.setBalance(prev.data.Balance)
		newObj.setUpload(prev.data.Upload)
		newObj.setNum(prev.data.Num)
	}
}

func (db *StateDB) ForEachStorage(addr common.Address, cb func(key, value common.Hash) bool) error {
	so := db.getStateObject(addr)
	if so == nil {
		return nil
	}
	it := trie.NewIterator(so.getTrie().NodeIterator(nil))

	for it.Next() {
		key := common.BytesToHash(db.trie.GetKey(it.Key))
		if value, dirty := so.dirtyStorage[key]; dirty {
			if !cb(key, value) {
				return nil
			}
			continue
		}
		//cb(key, common.BytesToHash(it.Value))
		if len(it.Value) > 0 {
			_, content, _, err := rlp.Split(it.Value)
			if err != nil {
				return err
			}
			if !cb(key, common.BytesToHash(content)) {
				return nil
			}
		}
	}
	return nil
}

// 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:                 s.db.CopyTrie(s.trie),
		originalRoot:         s.originalRoot,
		accounts:             make(map[common.Hash][]byte),
		storages:             make(map[common.Hash]map[common.Hash][]byte),
		accountsOrigin:       make(map[common.Address][]byte),
		storagesOrigin:       make(map[common.Address]map[common.Hash][]byte),
		stateObjects:         make(map[common.Address]*stateObject, len(s.journal.dirties)),
		stateObjectsPending:  make(map[common.Address]struct{}, len(s.stateObjectsPending)),
		stateObjectsDirty:    make(map[common.Address]struct{}, len(s.journal.dirties)),
		stateObjectsDestruct: make(map[common.Address]*types.StateAccount, len(s.stateObjectsDestruct)),
		refund:               s.refund,
		logs:                 make(map[common.Hash][]*types.Log, len(s.logs)),
		logSize:              s.logSize,
		preimages:            make(map[common.Hash][]byte, len(s.preimages)),
		journal:              newJournal(),
		hasher:               crypto.NewKeccakState(),

		// In order for the block producer to be able to use and make additions
		// to the snapshot tree, we need to copy that as well. Otherwise, any
		// block mined by ourselves will cause gaps in the tree, and force the
		// miner to operate trie-backed only.
		snaps: s.snaps,
		snap:  s.snap,
	}
	// Copy the dirty states, logs, and preimages
	for addr := range s.journal.dirties {
		// As documented [here](https://github.com/CortexFoundation/CortexTheseus/pull/16485#issuecomment-380438527),
		// and in the Finalise-method, there is a case where an object is in the journal but not
		// in the stateObjects: OOG after touch on ripeMD prior to Byzantium. Thus, we need to check for
		// nil
		if object, exist := s.stateObjects[addr]; exist {
			// Even though the original object is dirty, we are not copying the journal,
			// so we need to make sure that anyside effect the journal would have caused
			// during a commit (or similar op) is already applied to the copy.
			state.stateObjects[addr] = object.deepCopy(state)

			state.stateObjectsDirty[addr] = struct{}{}
			state.stateObjectsPending[addr] = struct{}{} // Mark the copy pending to force external (account) commits
		}
	}
	// Above, we don't copy the actual journal. This means that if the copy is copied, the
	// loop above will be a no-op, since the copy's journal is empty.
	// Thus, here we iterate over stateObjects, to enable copies of copies
	for addr := range s.stateObjectsPending {
		if _, exist := state.stateObjects[addr]; !exist {
			state.stateObjects[addr] = s.stateObjects[addr].deepCopy(state)
		}
		state.stateObjectsPending[addr] = struct{}{}
	}
	for addr := range s.stateObjectsDirty {
		if _, exist := state.stateObjects[addr]; !exist {
			state.stateObjects[addr] = s.stateObjects[addr].deepCopy(state)
		}
		state.stateObjectsDirty[addr] = struct{}{}
	}
	// Deep copy the destruction flag.
	for addr, value := range s.stateObjectsDestruct {
		state.stateObjectsDestruct[addr] = value
	}
	// Deep copy the state changes made in the scope of block
	// along with their original values.
	state.accounts = copySet(s.accounts)
	state.storages = copy2DSet(s.storages)
	state.accountsOrigin = copySet(state.accountsOrigin)
	state.storagesOrigin = copy2DSet(state.storagesOrigin)

	// 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
	}
	// Deep copy the preimages occurred in the scope of block
	for hash, preimage := range s.preimages {
		state.preimages[hash] = preimage
	}
	// Do we need to copy the access list? In practice: No. At the start of a
	// transaction, the access list is 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 an empty list, so we do it anyway
	// to not blow up if we ever decide copy it in the middle of a transaction
	state.accessList = s.accessList.Copy()
	state.transientStorage = s.transientStorage.Copy()

	// If there's a prefetcher running, make an inactive copy of it that can
	// only access data but does not actively preload (since the user will not
	// know that they need to explicitly terminate an active copy).
	if s.prefetcher != nil {
		state.prefetcher = s.prefetcher.copy()
	}
	/*if s.snaps != nil {
		// In order for the miner to be able to use and make additions
		// to the snapshot tree, we need to copy that aswell.
		// Otherwise, any block mined by ourselves will cause gaps in the tree,
		// and force the miner to operate trie-backed only
		state.snaps = s.snaps
		state.snap = s.snap
		// deep copy needed
		state.accounts = make(map[common.Hash][]byte, len(s.accounts))
		for k, v := range s.accounts {
			state.accounts[k] = v
		}
		state.storages = make(map[common.Hash]map[common.Hash][]byte, len(s.storages))
		for k, v := range s.storages {
			temp := make(map[common.Hash][]byte, len(v))
			for kk, vv := range v {
				temp[kk] = vv
			}
			state.storages[k] = temp
		}
	}*/
	return state
}

// Snapshot returns an identifier for the current revision of the state.
func (s *StateDB) Snapshot() int {
	id := s.nextRevisionId
	s.nextRevisionId++
	s.validRevisions = append(s.validRevisions, revision{id, s.journal.length()})
	return id
}

// RevertToSnapshot reverts all state changes made since the given revision.
func (s *StateDB) RevertToSnapshot(revid int) {
	// Find the snapshot in the stack of valid snapshots.
	idx := sort.Search(len(s.validRevisions), func(i int) bool {
		return s.validRevisions[i].id >= revid
	})
	if idx == len(s.validRevisions) || s.validRevisions[idx].id != revid {
		panic(fmt.Errorf("revision id %v cannot be reverted, %v, %v", revid, idx, len(s.validRevisions)))
	}
	snapshot := s.validRevisions[idx].journalIndex

	// Replay the journal to undo changes and remove invalidated snapshots
	s.journal.revert(s, snapshot)
	s.validRevisions = s.validRevisions[:idx]
}

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

// Finalise finalises the state by removing the s 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()) {
			obj.deleted = true

			// We need to maintain account deletions explicitly (will remain
			// set indefinitely).
			if _, ok := s.stateObjectsDestruct[obj.address]; !ok {
				s.stateObjectsDestruct[obj.address] = obj.origin
			}

			// If state snapshotting is active, also mark the destruction there.
			// Note, we can't do this only at the end of a block because multiple
			// transactions within the same block might self destruct and then
			// resurrect an account; but the snapshotter needs both events.
			delete(s.accounts, obj.addrHash)      // Clear out any previously updated account data (may be recreated via a resurrect)
			delete(s.storages, obj.addrHash)      // Clear out any previously updated storage data (may be recreated via a resurrect)
			delete(s.accountsOrigin, obj.address) // Clear out any previously updated account data (may be recreated via a resurrect)
			delete(s.storagesOrigin, obj.address) // Clear out any previously updated storage data (may be recreated via a resurrect)
		} else {
			obj.finalise(true) // Prefetch slots in the background
		}
		obj.created = false
		s.stateObjectsPending[addr] = struct{}{}
		s.stateObjectsDirty[addr] = struct{}{}

		// 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 {
		s.prefetcher.prefetch(s.originalRoot, addressesToPrefetch)
	}
	// 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, it gets aborted and irrevocably
	// modified after we start retrieving tries. Remove it from the statedb after
	// this round of use.
	//
	// This is weird pre-byzantium since the first tx runs with a prefetcher and
	// the remainder without, but pre-byzantium even the initial prefetcher is
	// useless, so no sleep lost.
	prefetcher := s.prefetcher
	if s.prefetcher != nil {
		defer func() {
			s.prefetcher.close()
			s.prefetcher = nil
		}()
	}
	// Although naively it makes sense to retrieve the account trie and then do
	// the contract storage and account updates sequentially, that short circuits
	// the account prefetcher. Instead, let's process all the storage updates
	// first, giving the account prefeches just a few more milliseconds of time
	// to pull useful data from disk.
	for addr := range s.stateObjectsPending {
		if obj := s.stateObjects[addr]; !obj.deleted {
			obj.updateRoot()
		}
	}
	// 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.
	if prefetcher != nil {
		if trie := prefetcher.trie(s.originalRoot); trie != nil {
			s.trie = trie
		}
	}
	usedAddrs := make([][]byte, 0, len(s.stateObjectsPending))
	for addr := range s.stateObjectsPending {
		if obj := s.stateObjects[addr]; obj.deleted {
			s.deleteStateObject(obj)
		} else {
			s.updateStateObject(obj)
		}
		usedAddrs = append(usedAddrs, common.CopyBytes(addr[:])) // Copy needed for closure
	}
	if prefetcher != nil {
		prefetcher.used(s.originalRoot, usedAddrs)
	}
	if len(s.stateObjectsPending) > 0 {
		s.stateObjectsPending = make(map[common.Address]struct{})
	}
	// Track the amount of time wasted on hashing the account trie
	if metrics.EnabledExpensive {
		defer func(start time.Time) { s.AccountHashes += time.Since(start) }(time.Now())
	}
	return s.trie.Hash()
}

// Prepare sets the current transaction hash and index and block hash which is
// used when the CVM emits new state logs.
func (s *StateDB) SetTxContext(thash common.Hash, ti int) {
	s.thash = thash
	s.txIndex = ti
}

func (s *StateDB) clearJournalAndRefund() {
	if len(s.journal.entries) > 0 {
		s.journal = newJournal()
		s.refund = 0
	}
	s.validRevisions = s.validRevisions[:0] // Snapshots can be created without journal entries
}

// Commit writes the state to the underlying in-memory trie database.
func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool) (common.Hash, error) {
	if s.dbErr != nil {
		return common.Hash{}, fmt.Errorf("commit aborted due to earlier error: %v", s.dbErr)
	}
	// Finalize any pending changes and merge everything into the tries
	s.IntermediateRoot(deleteEmptyObjects)

	// Commit objects to the trie, measuring the elapsed time
	codeWriter := s.db.DiskDB().NewBatch()
	for addr := range s.stateObjectsDirty {
		obj := s.stateObjects[addr]
		if obj.deleted {
			continue
		}
		// Write any contract code associated with the state object
		if obj.code != nil && obj.dirtyCode {
			rawdb.WriteCode(codeWriter, common.BytesToHash(obj.CodeHash()), obj.code)
			obj.dirtyCode = false
		}
		// Write any storage changes in the state object to its storage trie
		if err := obj.commit(); err != nil {
			return common.Hash{}, err
		}
	}
	if len(s.stateObjectsDirty) > 0 {
		s.stateObjectsDirty = make(map[common.Address]struct{})
	}
	if codeWriter.ValueSize() > 0 {
		if err := codeWriter.Write(); err != nil {
			log.Crit("Failed to commit dirty codes", "error", err)
		}
	}
	// Write the account trie changes, measuing the amount of wasted time
	var start time.Time
	if metrics.EnabledExpensive {
		start = time.Now()
	}
	// The onleaf func is called _serially_, so we can reuse the same account
	// for unmarshalling every time.
	var account types.StateAccount
	root, err := s.trie.Commit(func(_ [][]byte, _ []byte, leaf []byte, parent common.Hash) error {
		if err := rlp.DecodeBytes(leaf, &account); err != nil {
			return nil
		}
		if account.Root != types.EmptyRootHash {
			s.db.TrieDB().Reference(account.Root, parent)
		}
		return nil
	})
	if metrics.EnabledExpensive {
		s.AccountCommits += time.Since(start)
	}
	// If snapshotting is enabled, update the snapshot tree with this new version
	if s.snap != nil {
		if metrics.EnabledExpensive {
			defer func(start time.Time) { s.SnapshotCommits += time.Since(start) }(time.Now())
		}
		// Only update if there's a state transition (skip empty Clique blocks)
		if parent := s.snap.Root(); parent != root {
			if err := s.snaps.Update(root, parent, s.convertAccountSet(s.stateObjectsDestruct), s.accounts, s.storages); err != nil {
				log.Warn("Failed to update snapshot tree", "from", parent, "to", 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 := s.snaps.Cap(root, 128); err != nil {
				log.Warn("Failed to cap snapshot tree", "root", root, "layers", 128, "err", err)
			}
		}
		if metrics.EnabledExpensive {
			s.SnapshotCommits += time.Since(start)
		}
		s.snap = nil
	}
	if root == (common.Hash{}) {
		root = types.EmptyRootHash
	}
	/*origin := s.originalRoot
	if origin == (common.Hash{}) {
		origin = types.EmptyRootHash
	}
	if root != origin {
		start := time.Now()
			set := &triestate.Set{
				Accounts:   s.accountsOrigin,
				Storages:   s.storagesOrigin,
				Incomplete: incomplete,
			}
			if err := s.db.TrieDB().Update(root, origin, nodes, set); err != nil {
				return common.Hash{}, err
			}
			s.originalRoot = root

		if metrics.EnabledExpensive {
			s.TrieDBCommits += time.Since(start)
		}
	}*/

	// Clear all internal flags at the end of commit operation.
	s.accounts = make(map[common.Hash][]byte)
	s.storages = make(map[common.Hash]map[common.Hash][]byte)
	s.accountsOrigin = make(map[common.Address][]byte)
	s.storagesOrigin = make(map[common.Address]map[common.Hash][]byte)
	s.stateObjectsDirty = make(map[common.Address]struct{})
	s.stateObjectsDestruct = make(map[common.Address]*types.StateAccount)

	return root, err
}

// AddAddressToAccessList adds the given address to the access list
func (s *StateDB) AddAddressToAccessList(addr common.Address) {
	if s.accessList.AddAddress(addr) {
		s.journal.append(accessListAddAccountChange{&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.append(accessListAddAccountChange{&addr})
	}
	if slotMod {
		s.journal.append(accessListAddSlotChange{
			address: &addr,
			slot:    &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)
}

func (s *StateDB) convertAccountSet(set map[common.Address]*types.StateAccount) map[common.Hash]struct{} {
	ret := make(map[common.Hash]struct{}, len(set))
	for addr := range set {
		obj, exist := s.stateObjects[addr]
		if !exist {
			ret[crypto.Keccak256Hash(addr[:])] = struct{}{}
		} else {
			ret[obj.addrHash] = struct{}{}
		}
	}
	return ret
}

// copySet returns a deep-copied set.
func copySet[k comparable](set map[k][]byte) map[k][]byte {
	copied := make(map[k][]byte, len(set))
	for key, val := range set {
		copied[key] = common.CopyBytes(val)
	}
	return copied
}

// copy2DSet returns a two-dimensional deep-copied set.
func copy2DSet[k comparable](set map[k]map[common.Hash][]byte) map[k]map[common.Hash][]byte {
	copied := make(map[k]map[common.Hash][]byte, len(set))
	for addr, subset := range set {
		copied[addr] = make(map[common.Hash][]byte, len(subset))
		for key, val := range subset {
			copied[addr][key] = common.CopyBytes(val)
		}
	}
	return copied
}