// 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/ava-labs/go-ethereum/common"
"github.com/ava-labs/go-ethereum/crypto"
"github.com/ava-labs/go-ethereum/metrics"
"github.com/ava-labs/go-ethereum/rlp"
)
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)
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 Account
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
dirtyStorage Storage // Storage entries that need to be flushed to disk
fakeStorage Storage // Fake storage which constructed by caller for debugging purpose.
// 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)
}
// Account is the Ethereum consensus representation of accounts.
// These objects are stored in the main account trie.
type Account struct {
Nonce uint64
Balance *big.Int
Root common.Hash // merkle root of the storage trie
CodeHash []byte
IsMultiCoin bool
}
// newObject creates a state object.
func newObject(db *StateDB, address common.Address, data Account) *stateObject {
if data.Balance == nil {
data.Balance = new(big.Int)
}
if data.CodeHash == nil {
data.CodeHash = emptyCodeHash
}
return &stateObject{
db: db,
address: address,
addrHash: crypto.Keccak256Hash(address[:]),
data: data,
originStorage: 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)
}
}
func (s *stateObject) getTrie(db Database) Trie {
if s.trie == nil {
var err error
s.trie, err = db.OpenStorageTrie(s.addrHash, s.data.Root)
if err != nil {
s.trie, _ = db.OpenStorageTrie(s.addrHash, common.Hash{})
s.setError(fmt.Errorf("can't create storage trie: %v", err))
}
}
return s.trie
}
// GetState retrieves a value from the account storage trie.
func (s *stateObject) GetState(db Database, key common.Hash) common.Hash {
// If the fake storage is set, only lookup the state here(in the debugging mode)
if s.fakeStorage != nil {
return s.fakeStorage[key]
}
// 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 the fake storage is set, only lookup the state here(in the debugging mode)
if s.fakeStorage != nil {
return s.fakeStorage[key]
}
// If we have the original value cached, return that
value, cached := s.originStorage[key]
if cached {
return value
}
// Track the amount of time wasted on reading the storage trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageReads += time.Since(start) }(time.Now())
}
// Otherwise load the value from the database
enc, err := s.getTrie(db).TryGet(key[:])
if err != nil {
s.setError(err)
return 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 fake storage is set, put the temporary state update here.
if s.fakeStorage != nil {
s.fakeStorage[key] = value
return
}
// 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)
}
// SetStorage replaces the entire state storage with the given one.
//
// After this function is called, all original state will be ignored and state
// lookup only happens in the fake state storage.
//
// Note this function should only be used for debugging purpose.
func (s *stateObject) SetStorage(storage map[common.Hash]common.Hash) {
// Allocate fake storage if it's nil.
if s.fakeStorage == nil {
s.fakeStorage = make(Storage)
}
for key, value := range storage {
s.fakeStorage[key] = value
}
// Don't bother journal since this function should only be used for
// debugging and the `fake` storage won't be committed to database.
}
func (s *stateObject) setState(key, value common.Hash) {
s.dirtyStorage[key] = value
}
// updateTrie writes cached storage modifications into the object's storage trie.
func (s *stateObject) updateTrie(db Database) Trie {
// Track the amount of time wasted on updating the storge trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageUpdates += time.Since(start) }(time.Now())
}
// Update all the dirty slots in the trie
tr := s.getTrie(db)
for key, value := range s.dirtyStorage {
delete(s.dirtyStorage, key)
// Skip noop changes, persist actual changes
if value == s.originStorage[key] {
continue
}
s.originStorage[key] = value
if (value == common.Hash{}) {
s.setError(tr.TryDelete(key[:]))
continue
}
// Encoding []byte cannot fail, ok to ignore the error.
v, _ := rlp.EncodeToBytes(bytes.TrimLeft(value[:], "\x00"))
s.setError(tr.TryUpdate(key[:], v))
}
return tr
}
// UpdateRoot sets the trie root to the current root hash of
func (s *stateObject) updateRoot(db Database) {
s.updateTrie(db)
// Track the amount of time wasted on hashing the storge trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageHashes += time.Since(start) }(time.Now())
}
s.data.Root = s.trie.Hash()
}
// CommitTrie the storage trie of the object to db.
// This updates the trie root.
func (s *stateObject) CommitTrie(db Database) error {
s.updateTrie(db)
if s.dbErr != nil {
return s.dbErr
}
// Track the amount of time wasted on committing the storge trie
if metrics.EnabledExpensive {
defer func(start time.Time) { s.db.StorageCommits += time.Since(start) }(time.Now())
}
root, err := s.trie.Commit(nil)
if err == nil {
s.data.Root = root
}
return err
}
// AddBalance removes amount from c's balance.
// It is used to add funds to the destination account of a transfer.
func (s *stateObject) AddBalance(amount *big.Int) {
// EIP158: 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 c'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)
}
// AddBalance removes amount from c's balance.
// It is used to add funds to the destination account of a transfer.
func (s *stateObject) AddBalanceMultiCoin(coinID common.Hash, amount *big.Int, db Database) {
if amount.Sign() == 0 {
if s.empty() {
s.touch()
}
return
}
s.SetBalanceMultiCoin(coinID, new(big.Int).Add(s.BalanceMultiCoin(coinID, db), amount), db)
}
// SubBalance removes amount from c's balance.
// It is used to remove funds from the origin account of a transfer.
func (s *stateObject) SubBalanceMultiCoin(coinID common.Hash, amount *big.Int, db Database) {
if amount.Sign() == 0 {
return
}
s.SetBalanceMultiCoin(coinID, new(big.Int).Sub(s.BalanceMultiCoin(coinID, db), amount), db)
}
func (s *stateObject) SetBalanceMultiCoin(coinID common.Hash, amount *big.Int, db Database) {
NormalizeCoinID(&coinID)
s.SetState(db, coinID, common.BigToHash(amount))
}
func (s *stateObject) setBalance(amount *big.Int) {
s.data.Balance = amount
}
func (s *stateObject) enableMultiCoin() {
s.data.IsMultiCoin = true
}
// Return the gas back to the origin. Used by the Virtual machine or Closures
func (s *stateObject) ReturnGas(gas *big.Int) {}
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.suicided = s.suicided
stateObject.dirtyCode = s.dirtyCode
stateObject.deleted = s.deleted
return stateObject
}
//
// Attribute accessors
//
// 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
}
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 IsMultiCoinKey(key common.Hash) bool {
return key[0]&0x01 == 0x01
}
func NormalizeCoinID(coinID *common.Hash) {
coinID[0] |= 0x01
}
func NormalizeStateKey(key *common.Hash) {
key[0] &= 0xfe
}
func (s *stateObject) BalanceMultiCoin(coinID common.Hash, db Database) *big.Int {
NormalizeCoinID(&coinID)
return s.GetState(db, coinID).Big()
}
func (s *stateObject) EnableMultiCoin() bool {
if s.data.IsMultiCoin {
return false
}
s.db.journal.append(multiCoinEnable{
account: &s.address,
})
s.enableMultiCoin()
return true
}
func (s *stateObject) IsMultiCoin() bool {
return s.data.IsMultiCoin
}
func (s *stateObject) Nonce() uint64 {
return s.data.Nonce
}
// 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")
}