1 files changed, 499 insertions, 0 deletions
diff --git a/core/state/state_object.go b/core/state/state_object.go
new file mode 100644
index 0000000..9c47dc4
--- /dev/null
+++ b/core/state/state_object.go
@@ -0,0 +1,499 @@
+// 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")
+}