plugeth/core/state/state_object.go

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// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
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//
// The go-ethereum library is free software: you can redistribute it and/or modify
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// 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,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// 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/>.
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package state
import (
"bytes"
"fmt"
"io"
"math/big"
"time"
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"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
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"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
var emptyCodeHash = crypto.Keccak256(nil)
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
// 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
// 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 delete 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, emptyCodeHash)
}
// 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 = emptyCodeHash
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}
if data.Root == (common.Hash{}) {
data.Root = emptyRoot
}
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)
}
// setError remembers the first non-nil error it is called with.
func (s *stateObject) setError(err error) {
if s.dbErr == nil {
s.dbErr = err
}
}
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 != emptyRoot && 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
)
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 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.setError(err)
return common.Hash{}
}
enc, err = tr.TryGet(key.Bytes())
if metrics.EnabledExpensive {
s.db.StorageReads += time.Since(start)
}
if err != nil {
s.setError(err)
return common.Hash{}
}
}
var value common.Hash
if len(enc) > 0 {
_, content, _, err := rlp.Split(enc)
if err != nil {
s.setError(err)
}
value.SetBytes(content)
}
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 != emptyRoot {
s.db.prefetcher.prefetch(s.addrHash, s.data.Root, 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.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
var v []byte
if (value == common.Hash{}) {
if err := tr.TryDelete(key[:]); err != nil {
s.setError(err)
return nil, err
}
s.db.StorageDeleted += 1
} else {
// Encoding []byte cannot fail, ok to ignore the error.
v, _ = rlp.EncodeToBytes(common.TrimLeftZeroes(value[:]))
if err := tr.TryUpdate(key[:], v); err != nil {
s.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[:])] = v // v 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 {
s.setError(fmt.Errorf("updateRoot (%x) error: %w", s.address, err))
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) (*trie.NodeSet, error) {
tr, err := s.updateTrie(db)
if err != nil {
return nil, err
}
if s.dbErr != nil {
return nil, s.dbErr
}
// 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, err := tr.Commit(false)
if err == nil {
s.data.Root = root
}
return nodes, err
}
// 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)
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}
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
//
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// 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(), emptyCodeHash) {
return nil
}
code, err := db.ContractCode(s.addrHash, common.BytesToHash(s.CodeHash()))
if err != nil {
s.setError(fmt.Errorf("can't load code hash %x: %v", s.CodeHash(), err))
}
s.code = code
return code
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}
// 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(), emptyCodeHash) {
return 0
}
size, err := db.ContractCodeSize(s.addrHash, common.BytesToHash(s.CodeHash()))
if err != nil {
s.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
}
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// Value is never called, but must be present to allow stateObject to be used
// as a vm.Account interface that also satisfies the vm.ContractRef
// interface. Interfaces are awesome.
func (s *stateObject) Value() *big.Int {
panic("Value on stateObject should never be called")
}