// 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 provides a caching layer atop the Ethereum state trie.
package state
import (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/ethdb"
"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"
)
// The starting nonce determines the default nonce when new accounts are being
// created.
var StartingNonce uint64
// StateDBs within the ethereum protocol are used to store anything
// within the merkle trie. StateDBs take care of caching and storing
// nested states. It's the general query interface to retrieve:
// * Contracts
// * Accounts
type StateDB struct {
db ethdb.Database
trie *trie.SecureTrie
stateObjects map[string]*StateObject
refund *big.Int
thash, bhash common.Hash
txIndex int
logs map[common.Hash]vm.Logs
logSize uint
}
// Create a new state from a given trie
func New(root common.Hash, db ethdb.Database) (*StateDB, error) {
tr, err := trie.NewSecure(root, db)
if err != nil {
return nil, err
}
return &StateDB{
db: db,
trie: tr,
stateObjects: make(map[string]*StateObject),
refund: new(big.Int),
logs: make(map[common.Hash]vm.Logs),
}, nil
}
// Reset clears out all emphemeral state objects from the state db, but keeps
// the underlying state trie to avoid reloading data for the next operations.
func (self *StateDB) Reset(root common.Hash) error {
var (
err error
tr = self.trie
)
if self.trie.Hash() != root {
if tr, err = trie.NewSecure(root, self.db); err != nil {
return err
}
}
*self = StateDB{
db: self.db,
trie: tr,
stateObjects: make(map[string]*StateObject),
refund: new(big.Int),
logs: make(map[common.Hash]vm.Logs),
}
return nil
}
func (self *StateDB) StartRecord(thash, bhash common.Hash, ti int) {
self.thash = thash
self.bhash = bhash
self.txIndex = ti
}
func (self *StateDB) AddLog(log *vm.Log) {
log.TxHash = self.thash
log.BlockHash = self.bhash
log.TxIndex = uint(self.txIndex)
log.Index = self.logSize
self.logs[self.thash] = append(self.logs[self.thash], log)
self.logSize++
}
func (self *StateDB) GetLogs(hash common.Hash) vm.Logs {
return self.logs[hash]
}
func (self *StateDB) Logs() vm.Logs {
var logs vm.Logs
for _, lgs := range self.logs {
logs = append(logs, lgs...)
}
return logs
}
func (self *StateDB) AddRefund(gas *big.Int) {
self.refund.Add(self.refund, gas)
}
func (self *StateDB) HasAccount(addr common.Address) bool {
return self.GetStateObject(addr) != nil
}
func (self *StateDB) Exist(addr common.Address) bool {
return self.GetStateObject(addr) != nil
}
func (self *StateDB) GetAccount(addr common.Address) vm.Account {
return self.GetStateObject(addr)
}
// Retrieve the balance from the given address or 0 if object not found
func (self *StateDB) GetBalance(addr common.Address) *big.Int {
stateObject := self.GetStateObject(addr)
if stateObject != nil {
return stateObject.balance
}
return common.Big0
}
func (self *StateDB) GetNonce(addr common.Address) uint64 {
stateObject := self.GetStateObject(addr)
if stateObject != nil {
return stateObject.nonce
}
return StartingNonce
}
func (self *StateDB) GetCode(addr common.Address) []byte {
stateObject := self.GetStateObject(addr)
if stateObject != nil {
return stateObject.code
}
return nil
}
func (self *StateDB) GetCodeHash(addr common.Address) common.Hash {
stateObject := self.GetStateObject(addr)
if stateObject != nil {
return common.BytesToHash(stateObject.codeHash)
}
return common.Hash{}
}
func (self *StateDB) GetState(a common.Address, b common.Hash) common.Hash {
stateObject := self.GetStateObject(a)
if stateObject != nil {
return stateObject.GetState(b)
}
return common.Hash{}
}
func (self *StateDB) IsDeleted(addr common.Address) bool {
stateObject := self.GetStateObject(addr)
if stateObject != nil {
return stateObject.remove
}
return false
}
/*
* SETTERS
*/
func (self *StateDB) AddBalance(addr common.Address, amount *big.Int) {
stateObject := self.GetOrNewStateObject(addr)
if stateObject != nil {
stateObject.AddBalance(amount)
}
}
func (self *StateDB) SetNonce(addr common.Address, nonce uint64) {
stateObject := self.GetOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetNonce(nonce)
}
}
func (self *StateDB) SetCode(addr common.Address, code []byte) {
stateObject := self.GetOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetCode(code)
}
}
func (self *StateDB) SetState(addr common.Address, key common.Hash, value common.Hash) {
stateObject := self.GetOrNewStateObject(addr)
if stateObject != nil {
stateObject.SetState(key, value)
}
}
func (self *StateDB) Delete(addr common.Address) bool {
stateObject := self.GetStateObject(addr)
if stateObject != nil {
stateObject.MarkForDeletion()
stateObject.balance = new(big.Int)
return true
}
return false
}
//
// Setting, updating & deleting state object methods
//
// Update the given state object and apply it to state trie
func (self *StateDB) UpdateStateObject(stateObject *StateObject) {
addr := stateObject.Address()
data, err := rlp.EncodeToBytes(stateObject)
if err != nil {
panic(fmt.Errorf("can't encode object at %x: %v", addr[:], err))
}
self.trie.Update(addr[:], data)
}
// Delete the given state object and delete it from the state trie
func (self *StateDB) DeleteStateObject(stateObject *StateObject) {
stateObject.deleted = true
addr := stateObject.Address()
self.trie.Delete(addr[:])
//delete(self.stateObjects, addr.Str())
}
// Retrieve a state object given my the address. Nil if not found
func (self *StateDB) GetStateObject(addr common.Address) (stateObject *StateObject) {
stateObject = self.stateObjects[addr.Str()]
if stateObject != nil {
if stateObject.deleted {
stateObject = nil
}
return stateObject
}
data := self.trie.Get(addr[:])
if len(data) == 0 {
return nil
}
stateObject, err := DecodeObject(addr, self.db, data)
if err != nil {
glog.Errorf("can't decode object at %x: %v", addr[:], err)
return nil
}
self.SetStateObject(stateObject)
return stateObject
}
func (self *StateDB) SetStateObject(object *StateObject) {
self.stateObjects[object.Address().Str()] = object
}
// Retrieve a state object or create a new state object if nil
func (self *StateDB) GetOrNewStateObject(addr common.Address) *StateObject {
stateObject := self.GetStateObject(addr)
if stateObject == nil || stateObject.deleted {
stateObject = self.CreateStateObject(addr)
}
return stateObject
}
// NewStateObject create a state object whether it exist in the trie or not
func (self *StateDB) newStateObject(addr common.Address) *StateObject {
if glog.V(logger.Core) {
glog.Infof("(+) %x\n", addr)
}
stateObject := NewStateObject(addr, self.db)
stateObject.SetNonce(StartingNonce)
self.stateObjects[addr.Str()] = stateObject
return stateObject
}
// Creates creates a new state object and takes ownership. This is different from "NewStateObject"
func (self *StateDB) CreateStateObject(addr common.Address) *StateObject {
// Get previous (if any)
so := self.GetStateObject(addr)
// Create a new one
newSo := self.newStateObject(addr)
// If it existed set the balance to the new account
if so != nil {
newSo.balance = so.balance
}
return newSo
}
func (self *StateDB) CreateAccount(addr common.Address) vm.Account {
return self.CreateStateObject(addr)
}
//
// Setting, copying of the state methods
//
func (self *StateDB) Copy() *StateDB {
// ignore error - we assume state-to-be-copied always exists
state, _ := New(common.Hash{}, self.db)
state.trie = self.trie
for k, stateObject := range self.stateObjects {
state.stateObjects[k] = stateObject.Copy()
}
state.refund.Set(self.refund)
for hash, logs := range self.logs {
state.logs[hash] = make(vm.Logs, len(logs))
copy(state.logs[hash], logs)
}
state.logSize = self.logSize
return state
}
func (self *StateDB) Set(state *StateDB) {
self.trie = state.trie
self.stateObjects = state.stateObjects
self.refund = state.refund
self.logs = state.logs
self.logSize = state.logSize
}
func (self *StateDB) GetRefund() *big.Int {
return self.refund
}
// IntermediateRoot computes the current root hash of the state trie.
// It is called in between transactions to get the root hash that
// goes into transaction receipts.
func (s *StateDB) IntermediateRoot() common.Hash {
s.refund = new(big.Int)
for _, stateObject := range s.stateObjects {
if stateObject.dirty {
if stateObject.remove {
s.DeleteStateObject(stateObject)
} else {
stateObject.Update()
s.UpdateStateObject(stateObject)
}
stateObject.dirty = false
}
}
return s.trie.Hash()
}
// DeleteSuicides flags the suicided objects for deletion so that it
// won't be referenced again when called / queried up on.
//
// DeleteSuicides should not be used for consensus related updates
// under any circumstances.
func (s *StateDB) DeleteSuicides() {
// Reset refund so that any used-gas calculations can use
// this method.
s.refund = new(big.Int)
for _, stateObject := range s.stateObjects {
if stateObject.dirty {
// If the object has been removed by a suicide
// flag the object as deleted.
if stateObject.remove {
stateObject.deleted = true
}
stateObject.dirty = false
}
}
}
// Commit commits all state changes to the database.
func (s *StateDB) Commit() (root common.Hash, err error) {
root, batch := s.CommitBatch()
return root, batch.Write()
}
// CommitBatch commits all state changes to a write batch but does not
// execute the batch. It is used to validate state changes against
// the root hash stored in a block.
func (s *StateDB) CommitBatch() (root common.Hash, batch ethdb.Batch) {
batch = s.db.NewBatch()
root, _ = s.commit(batch)
return root, batch
}
func (s *StateDB) commit(db trie.DatabaseWriter) (common.Hash, error) {
s.refund = new(big.Int)
for _, stateObject := range s.stateObjects {
if stateObject.remove {
// If the object has been removed, don't bother syncing it
// and just mark it for deletion in the trie.
s.DeleteStateObject(stateObject)
} else {
// Write any contract code associated with the state object
if len(stateObject.code) > 0 {
if err := db.Put(stateObject.codeHash, stateObject.code); err != nil {
return common.Hash{}, err
}
}
// Write any storage changes in the state object to its trie.
stateObject.Update()
// Commit the trie of the object to the batch.
// This updates the trie root internally, so
// getting the root hash of the storage trie
// through UpdateStateObject is fast.
if _, err := stateObject.trie.CommitTo(db); err != nil {
return common.Hash{}, err
}
// Update the object in the account trie.
s.UpdateStateObject(stateObject)
}
stateObject.dirty = false
}
return s.trie.CommitTo(db)
}
func (self *StateDB) Refunds() *big.Int {
return self.refund
}
// Debug stuff
func (self *StateDB) CreateOutputForDiff() {
for _, stateObject := range self.stateObjects {
stateObject.CreateOutputForDiff()
}
}