erigon-pulse/core/state/state_object.go
Jeffrey Wilcke 3fc7c97827 core, core/vm: implemented a generic environment (#3348)
Environment is now a struct (not an interface). This
reduces a lot of tech-debt throughout the codebase where a virtual
machine environment had to be implemented in order to test or run it.

The new environment is suitable to be used en the json tests, core
consensus and light client.
2016-12-06 02:16:03 +01:00

400 lines
11 KiB
Go

// 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 *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.SecureTrie // storage trie, which becomes non-nil on first access
code Code // contract bytecode, which gets set when code is loaded
cachedStorage Storage // Storage entry cache to avoid duplicate reads
dirtyStorage Storage // Storage entries that need to be flushed to disk
// 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
touched bool
deleted bool
onDirty func(addr common.Address) // Callback method to mark a state object newly dirty
}
// empty returns whether the account is considered empty.
func (s *StateObject) empty() bool {
return s.data.Nonce == 0 && s.data.Balance.BitLen() == 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
}
// newObject creates a state object.
func newObject(db *StateDB, 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{db: db, address: address, data: data, cachedStorage: make(Storage), dirtyStorage: 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) markSuicided() {
self.suicided = 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) touch() {
c.db.journal = append(c.db.journal, touchChange{
account: &c.address,
prev: c.touched,
})
if c.onDirty != nil {
c.onDirty(c.Address())
c.onDirty = nil
}
c.touched = true
}
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, 0)
if err != nil {
c.trie, _ = trie.NewSecure(common.Hash{}, db, 0)
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.cachedStorage[key]
if exists {
return value
}
// Load from DB in case it is missing.
if enc := self.getTrie(db).Get(key[:]); len(enc) > 0 {
_, content, _, err := rlp.Split(enc)
if err != nil {
self.setError(err)
}
value.SetBytes(content)
}
if (value != common.Hash{}) {
self.cachedStorage[key] = value
}
return value
}
// SetState updates a value in account storage.
func (self *StateObject) SetState(db trie.Database, key, value common.Hash) {
self.db.journal = append(self.db.journal, storageChange{
account: &self.address,
key: key,
prevalue: self.GetState(db, key),
})
self.setState(key, value)
}
func (self *StateObject) setState(key, value common.Hash) {
self.cachedStorage[key] = value
self.dirtyStorage[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.dirtyStorage {
delete(self.dirtyStorage, key)
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 {
return self.dbErr
}
root, err := self.trie.CommitTo(dbw)
if err == nil {
self.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 (c *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.Cmp(common.Big0) == 0 {
if c.empty() {
c.touch()
}
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)
}
}
// SubBalance removes amount from c's balance.
// It is used to remove funds from the origin account of a transfer.
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.db.journal = append(self.db.journal, balanceChange{
account: &self.address,
prev: new(big.Int).Set(self.data.Balance),
})
self.setBalance(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 *big.Int) {}
func (self *StateObject) deepCopy(db *StateDB, onDirty func(addr common.Address)) *StateObject {
stateObject := newObject(db, self.address, self.data, onDirty)
stateObject.trie = self.trie
stateObject.code = self.code
stateObject.dirtyStorage = self.dirtyStorage.Copy()
stateObject.cachedStorage = self.dirtyStorage.Copy()
stateObject.suicided = self.suicided
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
}
func (self *StateObject) SetCode(codeHash common.Hash, code []byte) {
prevcode := self.Code(self.db.db)
self.db.journal = append(self.db.journal, codeChange{
account: &self.address,
prevhash: self.CodeHash(),
prevcode: prevcode,
})
self.setCode(codeHash, code)
}
func (self *StateObject) setCode(codeHash common.Hash, code []byte) {
self.code = code
self.data.CodeHash = codeHash[:]
self.dirtyCode = true
if self.onDirty != nil {
self.onDirty(self.Address())
self.onDirty = nil
}
}
func (self *StateObject) SetNonce(nonce uint64) {
self.db.journal = append(self.db.journal, nonceChange{
account: &self.address,
prev: self.data.Nonce,
})
self.setNonce(nonce)
}
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.cachedStorage {
cb(h, value)
}
it := self.getTrie(self.db.db).Iterator()
for it.Next() {
// ignore cached values
key := common.BytesToHash(self.trie.GetKey(it.Key))
if _, ok := self.cachedStorage[key]; !ok {
cb(key, common.BytesToHash(it.Value))
}
}
}