bsc/core/state/state_object.go
Guillaume Ballet 45a3ab42aa
core/state: move slot RLP encoding into the MPT implementation (#27000)
Continuing with a series of PRs to make the Trie interface more generic, this PR moves
the RLP encoding of storage slots inside the StateTrie and light.Trie implementations,
as other types of tries don't use RLP.
2023-06-01 10:29:41 +02:00

505 lines
15 KiB
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
import (
"bytes"
"fmt"
"io"
"math/big"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie/trienode"
)
type Code []byte
func (c Code) String() string {
return string(c) //strings.Join(Disassemble(c), " ")
}
type Storage map[common.Hash]common.Hash
func (s Storage) String() (str string) {
for key, value := range s {
str += fmt.Sprintf("%X : %X\n", key, value)
}
return
}
func (s Storage) Copy() Storage {
cpy := make(Storage, len(s))
for key, value := range s {
cpy[key] = value
}
return cpy
}
// stateObject represents an Ethereum account which is being modified.
//
// The usage pattern is as follows:
// First you need to obtain a state object.
// Account values can be accessed and modified through the object.
// Finally, call commitTrie to write the modified storage trie into a database.
type stateObject struct {
address common.Address
addrHash common.Hash // hash of ethereum address of the account
data types.StateAccount
db *StateDB
// Write caches.
trie Trie // storage trie, which becomes non-nil on first access
code Code // contract bytecode, which gets set when code is loaded
originStorage Storage // Storage cache of original entries to dedup rewrites, reset for every transaction
pendingStorage Storage // Storage entries that need to be flushed to disk, at the end of an entire block
dirtyStorage Storage // Storage entries that have been modified in the current transaction execution
// Cache flags.
// When an object is marked suicided it will be deleted from the trie
// during the "update" phase of the state transition.
dirtyCode bool // true if the code was updated
suicided bool
deleted bool
}
// empty returns whether the account is considered empty.
func (s *stateObject) empty() bool {
return s.data.Nonce == 0 && s.data.Balance.Sign() == 0 && bytes.Equal(s.data.CodeHash, types.EmptyCodeHash.Bytes())
}
// newObject creates a state object.
func newObject(db *StateDB, address common.Address, data types.StateAccount) *stateObject {
if data.Balance == nil {
data.Balance = new(big.Int)
}
if data.CodeHash == nil {
data.CodeHash = types.EmptyCodeHash.Bytes()
}
if data.Root == (common.Hash{}) {
data.Root = types.EmptyRootHash
}
return &stateObject{
db: db,
address: address,
addrHash: crypto.Keccak256Hash(address[:]),
data: data,
originStorage: make(Storage),
pendingStorage: make(Storage),
dirtyStorage: make(Storage),
}
}
// EncodeRLP implements rlp.Encoder.
func (s *stateObject) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, &s.data)
}
func (s *stateObject) markSuicided() {
s.suicided = true
}
func (s *stateObject) touch() {
s.db.journal.append(touchChange{
account: &s.address,
})
if s.address == ripemd {
// Explicitly put it in the dirty-cache, which is otherwise generated from
// flattened journals.
s.db.journal.dirty(s.address)
}
}
// getTrie returns the associated storage trie. The trie will be opened
// if it's not loaded previously. An error will be returned if trie can't
// be loaded.
func (s *stateObject) getTrie(db Database) (Trie, error) {
if s.trie == nil {
// Try fetching from prefetcher first
// We don't prefetch empty tries
if s.data.Root != types.EmptyRootHash && s.db.prefetcher != nil {
// When the miner is creating the pending state, there is no
// prefetcher
s.trie = s.db.prefetcher.trie(s.addrHash, s.data.Root)
}
if s.trie == nil {
tr, err := db.OpenStorageTrie(s.db.originalRoot, s.addrHash, s.data.Root)
if err != nil {
return nil, err
}
s.trie = tr
}
}
return s.trie, nil
}
// GetState retrieves a value from the account storage trie.
func (s *stateObject) GetState(db Database, key common.Hash) common.Hash {
// If we have a dirty value for this state entry, return it
value, dirty := s.dirtyStorage[key]
if dirty {
return value
}
// Otherwise return the entry's original value
return s.GetCommittedState(db, key)
}
// GetCommittedState retrieves a value from the committed account storage trie.
func (s *stateObject) GetCommittedState(db Database, key common.Hash) common.Hash {
// If we have a pending write or clean cached, return that
if value, pending := s.pendingStorage[key]; pending {
return value
}
if value, cached := s.originStorage[key]; cached {
return value
}
// If the object was destructed in *this* block (and potentially resurrected),
// the storage has been cleared out, and we should *not* consult the previous
// database about any storage values. The only possible alternatives are:
// 1) resurrect happened, and new slot values were set -- those should
// have been handles via pendingStorage above.
// 2) we don't have new values, and can deliver empty response back
if _, destructed := s.db.stateObjectsDestruct[s.address]; destructed {
return common.Hash{}
}
// If no live objects are available, attempt to use snapshots
var (
enc []byte
err error
value common.Hash
)
if s.db.snap != nil {
start := time.Now()
enc, err = s.db.snap.Storage(s.addrHash, crypto.Keccak256Hash(key.Bytes()))
if metrics.EnabledExpensive {
s.db.SnapshotStorageReads += time.Since(start)
}
if len(enc) > 0 {
_, content, _, err := rlp.Split(enc)
if err != nil {
s.db.setError(err)
}
value.SetBytes(content)
}
}
// If the snapshot is unavailable or reading from it fails, load from the database.
if s.db.snap == nil || err != nil {
start := time.Now()
tr, err := s.getTrie(db)
if err != nil {
s.db.setError(err)
return common.Hash{}
}
val, err := tr.GetStorage(s.address, key.Bytes())
if metrics.EnabledExpensive {
s.db.StorageReads += time.Since(start)
}
if err != nil {
s.db.setError(err)
return common.Hash{}
}
value.SetBytes(val)
}
s.originStorage[key] = value
return value
}
// SetState updates a value in account storage.
func (s *stateObject) SetState(db Database, key, value common.Hash) {
// If the new value is the same as old, don't set
prev := s.GetState(db, key)
if prev == value {
return
}
// New value is different, update and journal the change
s.db.journal.append(storageChange{
account: &s.address,
key: key,
prevalue: prev,
})
s.setState(key, value)
}
func (s *stateObject) setState(key, value common.Hash) {
s.dirtyStorage[key] = value
}
// finalise moves all dirty storage slots into the pending area to be hashed or
// committed later. It is invoked at the end of every transaction.
func (s *stateObject) finalise(prefetch bool) {
slotsToPrefetch := make([][]byte, 0, len(s.dirtyStorage))
for key, value := range s.dirtyStorage {
s.pendingStorage[key] = value
if value != s.originStorage[key] {
slotsToPrefetch = append(slotsToPrefetch, common.CopyBytes(key[:])) // Copy needed for closure
}
}
if s.db.prefetcher != nil && prefetch && len(slotsToPrefetch) > 0 && s.data.Root != types.EmptyRootHash {
s.db.prefetcher.prefetch(s.addrHash, s.data.Root, s.address, slotsToPrefetch)
}
if len(s.dirtyStorage) > 0 {
s.dirtyStorage = make(Storage)
}
}
// updateTrie writes cached storage modifications into the object's storage trie.
// It will return nil if the trie has not been loaded and no changes have been
// made. An error will be returned if the trie can't be loaded/updated correctly.
func (s *stateObject) updateTrie(db Database) (Trie, error) {
// Make sure all dirty slots are finalized into the pending storage area
s.finalise(false) // Don't prefetch anymore, pull directly if need be
if len(s.pendingStorage) == 0 {
return s.trie, nil
}
// Track the amount of time wasted on updating the storage trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageUpdates += time.Since(start) }(time.Now())
}
// The snapshot storage map for the object
var (
storage map[common.Hash][]byte
hasher = s.db.hasher
)
tr, err := s.getTrie(db)
if err != nil {
s.db.setError(err)
return nil, err
}
// Insert all the pending updates into the trie
usedStorage := make([][]byte, 0, len(s.pendingStorage))
for key, value := range s.pendingStorage {
// Skip noop changes, persist actual changes
if value == s.originStorage[key] {
continue
}
s.originStorage[key] = value
// rlp-encoded value to be used by the snapshot
var snapshotVal []byte
if (value == common.Hash{}) {
if err := tr.DeleteStorage(s.address, key[:]); err != nil {
s.db.setError(err)
return nil, err
}
s.db.StorageDeleted += 1
} else {
trimmedVal := common.TrimLeftZeroes(value[:])
// Encoding []byte cannot fail, ok to ignore the error.
snapshotVal, _ = rlp.EncodeToBytes(trimmedVal)
if err := tr.UpdateStorage(s.address, key[:], trimmedVal); err != nil {
s.db.setError(err)
return nil, err
}
s.db.StorageUpdated += 1
}
// If state snapshotting is active, cache the data til commit
if s.db.snap != nil {
if storage == nil {
// Retrieve the old storage map, if available, create a new one otherwise
if storage = s.db.snapStorage[s.addrHash]; storage == nil {
storage = make(map[common.Hash][]byte)
s.db.snapStorage[s.addrHash] = storage
}
}
storage[crypto.HashData(hasher, key[:])] = snapshotVal // will be nil if it's deleted
}
usedStorage = append(usedStorage, common.CopyBytes(key[:])) // Copy needed for closure
}
if s.db.prefetcher != nil {
s.db.prefetcher.used(s.addrHash, s.data.Root, usedStorage)
}
if len(s.pendingStorage) > 0 {
s.pendingStorage = make(Storage)
}
return tr, nil
}
// UpdateRoot sets the trie root to the current root hash of. An error
// will be returned if trie root hash is not computed correctly.
func (s *stateObject) updateRoot(db Database) {
tr, err := s.updateTrie(db)
if err != nil {
return
}
// If nothing changed, don't bother with hashing anything
if tr == nil {
return
}
// Track the amount of time wasted on hashing the storage trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageHashes += time.Since(start) }(time.Now())
}
s.data.Root = tr.Hash()
}
// commitTrie submits the storage changes into the storage trie and re-computes
// the root. Besides, all trie changes will be collected in a nodeset and returned.
func (s *stateObject) commitTrie(db Database) (*trienode.NodeSet, error) {
tr, err := s.updateTrie(db)
if err != nil {
return nil, err
}
// If nothing changed, don't bother with committing anything
if tr == nil {
return nil, nil
}
// Track the amount of time wasted on committing the storage trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageCommits += time.Since(start) }(time.Now())
}
root, nodes := tr.Commit(false)
s.data.Root = root
return nodes, nil
}
// AddBalance adds amount to s's balance.
// It is used to add funds to the destination account of a transfer.
func (s *stateObject) AddBalance(amount *big.Int) {
// EIP161: We must check emptiness for the objects such that the account
// clearing (0,0,0 objects) can take effect.
if amount.Sign() == 0 {
if s.empty() {
s.touch()
}
return
}
s.SetBalance(new(big.Int).Add(s.Balance(), amount))
}
// SubBalance removes amount from s's balance.
// It is used to remove funds from the origin account of a transfer.
func (s *stateObject) SubBalance(amount *big.Int) {
if amount.Sign() == 0 {
return
}
s.SetBalance(new(big.Int).Sub(s.Balance(), amount))
}
func (s *stateObject) SetBalance(amount *big.Int) {
s.db.journal.append(balanceChange{
account: &s.address,
prev: new(big.Int).Set(s.data.Balance),
})
s.setBalance(amount)
}
func (s *stateObject) setBalance(amount *big.Int) {
s.data.Balance = amount
}
func (s *stateObject) deepCopy(db *StateDB) *stateObject {
stateObject := newObject(db, s.address, s.data)
if s.trie != nil {
stateObject.trie = db.db.CopyTrie(s.trie)
}
stateObject.code = s.code
stateObject.dirtyStorage = s.dirtyStorage.Copy()
stateObject.originStorage = s.originStorage.Copy()
stateObject.pendingStorage = s.pendingStorage.Copy()
stateObject.suicided = s.suicided
stateObject.dirtyCode = s.dirtyCode
stateObject.deleted = s.deleted
return stateObject
}
//
// Attribute accessors
//
// Address returns the address of the contract/account
func (s *stateObject) Address() common.Address {
return s.address
}
// Code returns the contract code associated with this object, if any.
func (s *stateObject) Code(db Database) []byte {
if s.code != nil {
return s.code
}
if bytes.Equal(s.CodeHash(), types.EmptyCodeHash.Bytes()) {
return nil
}
code, err := db.ContractCode(s.addrHash, common.BytesToHash(s.CodeHash()))
if err != nil {
s.db.setError(fmt.Errorf("can't load code hash %x: %v", s.CodeHash(), err))
}
s.code = code
return code
}
// CodeSize returns the size of the contract code associated with this object,
// or zero if none. This method is an almost mirror of Code, but uses a cache
// inside the database to avoid loading codes seen recently.
func (s *stateObject) CodeSize(db Database) int {
if s.code != nil {
return len(s.code)
}
if bytes.Equal(s.CodeHash(), types.EmptyCodeHash.Bytes()) {
return 0
}
size, err := db.ContractCodeSize(s.addrHash, common.BytesToHash(s.CodeHash()))
if err != nil {
s.db.setError(fmt.Errorf("can't load code size %x: %v", s.CodeHash(), err))
}
return size
}
func (s *stateObject) SetCode(codeHash common.Hash, code []byte) {
prevcode := s.Code(s.db.db)
s.db.journal.append(codeChange{
account: &s.address,
prevhash: s.CodeHash(),
prevcode: prevcode,
})
s.setCode(codeHash, code)
}
func (s *stateObject) setCode(codeHash common.Hash, code []byte) {
s.code = code
s.data.CodeHash = codeHash[:]
s.dirtyCode = true
}
func (s *stateObject) SetNonce(nonce uint64) {
s.db.journal.append(nonceChange{
account: &s.address,
prev: s.data.Nonce,
})
s.setNonce(nonce)
}
func (s *stateObject) setNonce(nonce uint64) {
s.data.Nonce = nonce
}
func (s *stateObject) CodeHash() []byte {
return s.data.CodeHash
}
func (s *stateObject) Balance() *big.Int {
return s.data.Balance
}
func (s *stateObject) Nonce() uint64 {
return s.data.Nonce
}