// 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"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
)
var emptyCodeHash = crypto.Keccak256(nil)
type Code []byte
func (self Code) String() string {
return string(self) //strings.Join(Disassemble(self), " ")
}
type Storage map[common.Hash]common.Hash
func (self Storage) String() (str string) {
for key, value := range self {
str += fmt.Sprintf("%X : %X\n", key, value)
}
return
}
func (self Storage) Copy() Storage {
cpy := make(Storage)
for key, value := range self {
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 // Ethereum address of this account
data Account
// 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.SecureTrie // storage trie, which becomes non-nil on first access
code Code // contract bytecode, which gets set when code is loaded
storage Storage // Cached storage (flushed when updated)
// Cache flags.
// When an object is marked for deletion it will be delete from the trie
// during the "update" phase of the state transition
dirtyCode bool // true if the code was updated
remove bool
deleted bool
onDirty func(addr common.Address) // Callback method to mark a state object newly dirty
}
// 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
codeSize *int
}
// NewObject creates a state object.
func NewObject(address common.Address, data Account, onDirty func(addr common.Address)) *StateObject {
if data.Balance == nil {
data.Balance = new(big.Int)
}
if data.CodeHash == nil {
data.CodeHash = emptyCodeHash
}
return &StateObject{address: address, data: data, storage: make(Storage), onDirty: onDirty}
}
// EncodeRLP implements rlp.Encoder.
func (c *StateObject) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, c.data)
}
// setError remembers the first non-nil error it is called with.
func (self *StateObject) setError(err error) {
if self.dbErr == nil {
self.dbErr = err
}
}
func (self *StateObject) MarkForDeletion() {
self.remove = true
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
if glog.V(logger.Core) {
glog.Infof("%x: #%d %v X\n", self.Address(), self.Nonce(), self.Balance())
}
}
func (c *StateObject) getTrie(db trie.Database) *trie.SecureTrie {
if c.trie == nil {
var err error
c.trie, err = trie.NewSecure(c.data.Root, db)
if err != nil {
c.trie, _ = trie.NewSecure(common.Hash{}, db)
c.setError(fmt.Errorf("can't create storage trie: %v", err))
}
}
return c.trie
}
// GetState returns a value in account storage.
func (self *StateObject) GetState(db trie.Database, key common.Hash) common.Hash {
value, exists := self.storage[key]
if exists {
return value
}
// Load from DB in case it is missing.
tr := self.getTrie(db)
var ret []byte
rlp.DecodeBytes(tr.Get(key[:]), &ret)
value = common.BytesToHash(ret)
if (value != common.Hash{}) {
self.storage[key] = value
}
return value
}
// SetState updates a value in account storage.
func (self *StateObject) SetState(key, value common.Hash) {
self.storage[key] = value
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
// updateTrie writes cached storage modifications into the object's storage trie.
func (self *StateObject) updateTrie(db trie.Database) {
tr := self.getTrie(db)
for key, value := range self.storage {
if (value == common.Hash{}) {
tr.Delete(key[:])
continue
}
// Encoding []byte cannot fail, ok to ignore the error.
v, _ := rlp.EncodeToBytes(bytes.TrimLeft(value[:], "\x00"))
tr.Update(key[:], v)
}
}
// UpdateRoot sets the trie root to the current root hash of
func (self *StateObject) UpdateRoot(db trie.Database) {
self.updateTrie(db)
self.data.Root = self.trie.Hash()
}
// CommitTrie the storage trie of the object to dwb.
// This updates the trie root.
func (self *StateObject) CommitTrie(db trie.Database, dbw trie.DatabaseWriter) error {
self.updateTrie(db)
if self.dbErr != nil {
fmt.Println("dbErr:", self.dbErr)
return self.dbErr
}
root, err := self.trie.CommitTo(dbw)
if err == nil {
self.data.Root = root
}
return err
}
func (c *StateObject) AddBalance(amount *big.Int) {
if amount.Cmp(common.Big0) == 0 {
return
}
c.SetBalance(new(big.Int).Add(c.Balance(), amount))
if glog.V(logger.Core) {
glog.Infof("%x: #%d %v (+ %v)\n", c.Address(), c.Nonce(), c.Balance(), amount)
}
}
func (c *StateObject) SubBalance(amount *big.Int) {
if amount.Cmp(common.Big0) == 0 {
return
}
c.SetBalance(new(big.Int).Sub(c.Balance(), amount))
if glog.V(logger.Core) {
glog.Infof("%x: #%d %v (- %v)\n", c.Address(), c.Nonce(), c.Balance(), amount)
}
}
func (self *StateObject) SetBalance(amount *big.Int) {
self.data.Balance = amount
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
// Return the gas back to the origin. Used by the Virtual machine or Closures
func (c *StateObject) ReturnGas(gas, price *big.Int) {}
func (self *StateObject) Copy(db trie.Database, onDirty func(addr common.Address)) *StateObject {
stateObject := NewObject(self.address, self.data, onDirty)
stateObject.trie = self.trie
stateObject.code = self.code
stateObject.storage = self.storage.Copy()
stateObject.remove = self.remove
stateObject.dirtyCode = self.dirtyCode
stateObject.deleted = self.deleted
return stateObject
}
//
// Attribute accessors
//
// Returns the address of the contract/account
func (c *StateObject) Address() common.Address {
return c.address
}
// Code returns the contract code associated with this object, if any.
func (self *StateObject) Code(db trie.Database) []byte {
if self.code != nil {
return self.code
}
if bytes.Equal(self.CodeHash(), emptyCodeHash) {
return nil
}
code, err := db.Get(self.CodeHash())
if err != nil {
self.setError(fmt.Errorf("can't load code hash %x: %v", self.CodeHash(), err))
}
self.code = code
return code
}
// CodeSize returns the size of the contract code associated with this object.
func (self *StateObject) CodeSize(db trie.Database) int {
if self.data.codeSize == nil {
self.data.codeSize = new(int)
*self.data.codeSize = len(self.Code(db))
}
return *self.data.codeSize
}
func (self *StateObject) SetCode(code []byte) {
self.code = code
self.data.CodeHash = crypto.Keccak256(code)
self.data.codeSize = new(int)
*self.data.codeSize = len(code)
self.dirtyCode = true
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
func (self *StateObject) SetNonce(nonce uint64) {
self.data.Nonce = nonce
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
func (self *StateObject) CodeHash() []byte {
return self.data.CodeHash
}
func (self *StateObject) Balance() *big.Int {
return self.data.Balance
}
func (self *StateObject) Nonce() uint64 {
return self.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 (self *StateObject) Value() *big.Int {
panic("Value on StateObject should never be called")
}
func (self *StateObject) ForEachStorage(cb func(key, value common.Hash) bool) {
// When iterating over the storage check the cache first
for h, value := range self.storage {
cb(h, value)
}
it := self.trie.Iterator()
for it.Next() {
// ignore cached values
key := common.BytesToHash(self.trie.GetKey(it.Key))
if _, ok := self.storage[key]; !ok {
cb(key, common.BytesToHash(it.Value))
}
}
}
