Refactored state, state object and vm

* The State and StateObject have been moved to their own package
* The VM is moved to it's own package

5 files changed, 656 insertions, 0 deletions

diff --git a/ethstate/.ethtest b/ethstate/.ethtest
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/ethstate/.ethtest
diff --git a/ethstate/errors.go b/ethstate/errors.go
new file mode 100644
index 000000000..d5d7db86b
--- /dev/null
+++ b/ethstate/errors.go
@@ -0,0 +1,23 @@
+package ethstate
+
+import (
+	"fmt"
+	"math/big"
+)
+
+type GasLimitErr struct {
+	Message string
+	Is, Max *big.Int
+}
+
+func IsGasLimitErr(err error) bool {
+	_, ok := err.(*GasLimitErr)
+
+	return ok
+}
+func (err *GasLimitErr) Error() string {
+	return err.Message
+}
+func GasLimitError(is, max *big.Int) *GasLimitErr {
+	return &GasLimitErr{Message: fmt.Sprintf("GasLimit error. Max %s, transaction would take it to %s", max, is), Is: is, Max: max}
+}
diff --git a/ethstate/state.go b/ethstate/state.go
new file mode 100644
index 000000000..a4b9b1e9c
--- /dev/null
+++ b/ethstate/state.go
@@ -0,0 +1,259 @@
+package ethstate
+
+import (
+	"github.com/ethereum/eth-go/ethcrypto"
+	"github.com/ethereum/eth-go/ethlog"
+	"github.com/ethereum/eth-go/ethtrie"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+var statelogger = ethlog.NewLogger("STATE")
+
+// States within the ethereum protocol are used to store anything
+// within the merkle trie. States take care of caching and storing
+// nested states. It's the general query interface to retrieve:
+// * Contracts
+// * Accounts
+type State struct {
+	// The trie for this structure
+	trie *ethtrie.Trie
+
+	stateObjects map[string]*StateObject
+
+	manifest *Manifest
+}
+
+// Create a new state from a given trie
+func NewState(trie *ethtrie.Trie) *State {
+	return &State{trie: trie, stateObjects: make(map[string]*StateObject), manifest: NewManifest()}
+}
+
+// Retrieve the balance from the given address or 0 if object not found
+func (self *State) GetBalance(addr []byte) *big.Int {
+	stateObject := self.GetStateObject(addr)
+	if stateObject != nil {
+		return stateObject.Amount
+	}
+
+	return ethutil.Big0
+}
+
+func (self *State) GetNonce(addr []byte) uint64 {
+	stateObject := self.GetStateObject(addr)
+	if stateObject != nil {
+		return stateObject.Nonce
+	}
+
+	return 0
+}
+
+//
+// Setting, updating & deleting state object methods
+//
+
+// Update the given state object and apply it to state trie
+func (self *State) UpdateStateObject(stateObject *StateObject) {
+	addr := stateObject.Address()
+
+	ethutil.Config.Db.Put(ethcrypto.Sha3Bin(stateObject.Code), stateObject.Code)
+
+	self.trie.Update(string(addr), string(stateObject.RlpEncode()))
+
+	self.manifest.AddObjectChange(stateObject)
+}
+
+// Delete the given state object and delete it from the state trie
+func (self *State) DeleteStateObject(stateObject *StateObject) {
+	self.trie.Delete(string(stateObject.Address()))
+
+	delete(self.stateObjects, string(stateObject.Address()))
+}
+
+// Retrieve a state object given my the address. Nil if not found
+func (self *State) GetStateObject(addr []byte) *StateObject {
+	addr = ethutil.Address(addr)
+
+	stateObject := self.stateObjects[string(addr)]
+	if stateObject != nil {
+		return stateObject
+	}
+
+	data := self.trie.Get(string(addr))
+	if len(data) == 0 {
+		return nil
+	}
+
+	stateObject = NewStateObjectFromBytes(addr, []byte(data))
+	self.stateObjects[string(addr)] = stateObject
+
+	return stateObject
+}
+
+// Retrieve a state object or create a new state object if nil
+func (self *State) GetOrNewStateObject(addr []byte) *StateObject {
+	stateObject := self.GetStateObject(addr)
+	if stateObject == nil {
+		stateObject = self.NewStateObject(addr)
+	}
+
+	return stateObject
+}
+
+// Create a state object whether it exist in the trie or not
+func (self *State) NewStateObject(addr []byte) *StateObject {
+	addr = ethutil.Address(addr)
+
+	statelogger.Infof("(+) %x\n", addr)
+
+	stateObject := NewStateObject(addr)
+	self.stateObjects[string(addr)] = stateObject
+
+	return stateObject
+}
+
+// Deprecated
+func (self *State) GetAccount(addr []byte) *StateObject {
+	return self.GetOrNewStateObject(addr)
+}
+
+//
+// Setting, copying of the state methods
+//
+
+func (s *State) Cmp(other *State) bool {
+	return s.trie.Cmp(other.trie)
+}
+
+func (self *State) Copy() *State {
+	if self.trie != nil {
+		state := NewState(self.trie.Copy())
+		for k, stateObject := range self.stateObjects {
+			state.stateObjects[k] = stateObject.Copy()
+		}
+
+		return state
+	}
+
+	return nil
+}
+
+func (self *State) Set(state *State) {
+	if state == nil {
+		panic("Tried setting 'state' to nil through 'Set'")
+	}
+
+	self.trie = state.trie
+	self.stateObjects = state.stateObjects
+}
+
+func (s *State) Root() interface{} {
+	return s.trie.Root
+}
+
+// Resets the trie and all siblings
+func (s *State) Reset() {
+	s.trie.Undo()
+
+	// Reset all nested states
+	for _, stateObject := range s.stateObjects {
+		if stateObject.state == nil {
+			continue
+		}
+
+		//stateObject.state.Reset()
+		stateObject.Reset()
+	}
+
+	s.Empty()
+}
+
+// Syncs the trie and all siblings
+func (s *State) Sync() {
+	// Sync all nested states
+	for _, stateObject := range s.stateObjects {
+		//s.UpdateStateObject(stateObject)
+
+		if stateObject.state == nil {
+			continue
+		}
+
+		stateObject.state.Sync()
+	}
+
+	s.trie.Sync()
+
+	s.Empty()
+}
+
+func (self *State) Empty() {
+	self.stateObjects = make(map[string]*StateObject)
+}
+
+func (self *State) Update() {
+	for _, stateObject := range self.stateObjects {
+		if stateObject.remove {
+			self.DeleteStateObject(stateObject)
+		} else {
+			stateObject.Sync()
+
+			self.UpdateStateObject(stateObject)
+		}
+	}
+
+	// FIXME trie delete is broken
+	valid, t2 := ethtrie.ParanoiaCheck(self.trie)
+	if !valid {
+		statelogger.Infof("Warn: PARANOIA: Different state root during copy %x vs %x\n", self.trie.Root, t2.Root)
+
+		self.trie = t2
+	}
+}
+
+// Debug stuff
+func (self *State) CreateOutputForDiff() {
+	for _, stateObject := range self.stateObjects {
+		stateObject.CreateOutputForDiff()
+	}
+}
+
+func (self *State) Manifest() *Manifest {
+	return self.manifest
+}
+
+// Object manifest
+//
+// The object manifest is used to keep changes to the state so we can keep track of the changes
+// that occurred during a state transitioning phase.
+type Manifest struct {
+	// XXX These will be handy in the future. Not important for now.
+	objectAddresses  map[string]bool
+	storageAddresses map[string]map[string]bool
+
+	objectChanges  map[string]*StateObject
+	storageChanges map[string]map[string]*big.Int
+}
+
+func NewManifest() *Manifest {
+	m := &Manifest{objectAddresses: make(map[string]bool), storageAddresses: make(map[string]map[string]bool)}
+	m.Reset()
+
+	return m
+}
+
+func (m *Manifest) Reset() {
+	m.objectChanges = make(map[string]*StateObject)
+	m.storageChanges = make(map[string]map[string]*big.Int)
+}
+
+func (m *Manifest) AddObjectChange(stateObject *StateObject) {
+	m.objectChanges[string(stateObject.Address())] = stateObject
+}
+
+func (m *Manifest) AddStorageChange(stateObject *StateObject, storageAddr []byte, storage *big.Int) {
+	if m.storageChanges[string(stateObject.Address())] == nil {
+		m.storageChanges[string(stateObject.Address())] = make(map[string]*big.Int)
+	}
+
+	m.storageChanges[string(stateObject.Address())][string(storageAddr)] = storage
+}
diff --git a/ethstate/state_object.go b/ethstate/state_object.go
new file mode 100644
index 000000000..d8513f37d
--- /dev/null
+++ b/ethstate/state_object.go
@@ -0,0 +1,339 @@
+package ethstate
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethcrypto"
+	"github.com/ethereum/eth-go/ethtrie"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+type Code []byte
+
+func (self Code) String() string {
+	return "" //strings.Join(Disassemble(self), " ")
+}
+
+type Storage map[string]*ethutil.Value
+
+func (self Storage) Copy() Storage {
+	cpy := make(Storage)
+	for key, value := range self {
+		// XXX Do we need a 'value' copy or is this sufficient?
+		cpy[key] = value
+	}
+
+	return cpy
+}
+
+type StateObject struct {
+	// Address of the object
+	address []byte
+	// Shared attributes
+	Amount   *big.Int
+	CodeHash []byte
+	Nonce    uint64
+	// Contract related attributes
+	state    *State
+	Code     Code
+	initCode Code
+
+	storage Storage
+
+	// Total gas pool is the total amount of gas currently
+	// left if this object is the coinbase. Gas is directly
+	// purchased of the coinbase.
+	gasPool *big.Int
+
+	// Mark for deletion
+	// When an object is marked for deletion it will be delete from the trie
+	// during the "update" phase of the state transition
+	remove bool
+}
+
+func (self *StateObject) Reset() {
+	self.storage = make(Storage)
+	self.state.Reset()
+}
+
+/*
+// Converts an transaction in to a state object
+func MakeContract(tx *Transaction, state *State) *StateObject {
+	// Create contract if there's no recipient
+	if tx.IsContract() {
+		addr := tx.CreationAddress()
+
+		contract := state.NewStateObject(addr)
+		contract.initCode = tx.Data
+		contract.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, ""))
+
+		return contract
+	}
+
+	return nil
+}
+*/
+
+func NewStateObject(addr []byte) *StateObject {
+	// This to ensure that it has 20 bytes (and not 0 bytes), thus left or right pad doesn't matter.
+	address := ethutil.Address(addr)
+
+	object := &StateObject{address: address, Amount: new(big.Int), gasPool: new(big.Int)}
+	object.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, ""))
+	object.storage = make(Storage)
+	object.gasPool = new(big.Int)
+
+	return object
+}
+
+func NewContract(address []byte, Amount *big.Int, root []byte) *StateObject {
+	contract := NewStateObject(address)
+	contract.Amount = Amount
+	contract.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, string(root)))
+
+	return contract
+}
+
+func NewStateObjectFromBytes(address, data []byte) *StateObject {
+	object := &StateObject{address: address}
+	object.RlpDecode(data)
+
+	return object
+}
+
+func (self *StateObject) MarkForDeletion() {
+	self.remove = true
+	statelogger.DebugDetailf("%x: #%d %v (deletion)\n", self.Address(), self.Nonce, self.Amount)
+}
+
+func (c *StateObject) GetAddr(addr []byte) *ethutil.Value {
+	return ethutil.NewValueFromBytes([]byte(c.state.trie.Get(string(addr))))
+}
+
+func (c *StateObject) SetAddr(addr []byte, value interface{}) {
+	c.state.trie.Update(string(addr), string(ethutil.NewValue(value).Encode()))
+}
+
+func (self *StateObject) GetStorage(key *big.Int) *ethutil.Value {
+	return self.getStorage(key.Bytes())
+}
+func (self *StateObject) SetStorage(key *big.Int, value *ethutil.Value) {
+	self.setStorage(key.Bytes(), value)
+}
+
+func (self *StateObject) getStorage(k []byte) *ethutil.Value {
+	key := ethutil.LeftPadBytes(k, 32)
+
+	value := self.storage[string(key)]
+	if value == nil {
+		value = self.GetAddr(key)
+
+		if !value.IsNil() {
+			self.storage[string(key)] = value
+		}
+	}
+
+	return value
+
+	//return self.GetAddr(key)
+}
+
+func (self *StateObject) setStorage(k []byte, value *ethutil.Value) {
+	key := ethutil.LeftPadBytes(k, 32)
+	self.storage[string(key)] = value.Copy()
+}
+
+// Iterate over each storage address and yield callback
+func (self *StateObject) EachStorage(cb ethtrie.EachCallback) {
+	// First loop over the uncommit/cached values in storage
+	for key, value := range self.storage {
+		// XXX Most iterators Fns as it stands require encoded values
+		encoded := ethutil.NewValue(value.Encode())
+		cb(key, encoded)
+	}
+
+	it := self.state.trie.NewIterator()
+	it.Each(func(key string, value *ethutil.Value) {
+		// If it's cached don't call the callback.
+		if self.storage[key] == nil {
+			cb(key, value)
+		}
+	})
+}
+
+func (self *StateObject) Sync() {
+	for key, value := range self.storage {
+		if value.Len() == 0 { // value.BigInt().Cmp(ethutil.Big0) == 0 {
+			//data := self.getStorage([]byte(key))
+			//fmt.Printf("deleting %x %x 0x%x\n", self.Address(), []byte(key), data)
+			self.state.trie.Delete(string(key))
+			continue
+		}
+
+		self.SetAddr([]byte(key), value)
+	}
+
+	valid, t2 := ethtrie.ParanoiaCheck(self.state.trie)
+	if !valid {
+		statelogger.Infof("Warn: PARANOIA: Different state storage root during copy %x vs %x\n", self.state.trie.Root, t2.Root)
+
+		self.state.trie = t2
+	}
+}
+
+func (c *StateObject) GetInstr(pc *big.Int) *ethutil.Value {
+	if int64(len(c.Code)-1) < pc.Int64() {
+		return ethutil.NewValue(0)
+	}
+
+	return ethutil.NewValueFromBytes([]byte{c.Code[pc.Int64()]})
+}
+
+func (c *StateObject) AddAmount(amount *big.Int) {
+	c.SetAmount(new(big.Int).Add(c.Amount, amount))
+
+	statelogger.Debugf("%x: #%d %v (+ %v)\n", c.Address(), c.Nonce, c.Amount, amount)
+}
+
+func (c *StateObject) SubAmount(amount *big.Int) {
+	c.SetAmount(new(big.Int).Sub(c.Amount, amount))
+
+	statelogger.Debugf("%x: #%d %v (- %v)\n", c.Address(), c.Nonce, c.Amount, amount)
+}
+
+func (c *StateObject) SetAmount(amount *big.Int) {
+	c.Amount = amount
+}
+
+//
+// Gas setters and getters
+//
+
+// Return the gas back to the origin. Used by the Virtual machine or Closures
+func (c *StateObject) ReturnGas(gas, price *big.Int) {}
+func (c *StateObject) ConvertGas(gas, price *big.Int) error {
+	total := new(big.Int).Mul(gas, price)
+	if total.Cmp(c.Amount) > 0 {
+		return fmt.Errorf("insufficient amount: %v, %v", c.Amount, total)
+	}
+
+	c.SubAmount(total)
+
+	return nil
+}
+
+func (self *StateObject) SetGasPool(gasLimit *big.Int) {
+	self.gasPool = new(big.Int).Set(gasLimit)
+
+	statelogger.DebugDetailf("%x: fuel (+ %v)", self.Address(), self.gasPool)
+}
+
+func (self *StateObject) BuyGas(gas, price *big.Int) error {
+	if self.gasPool.Cmp(gas) < 0 {
+		return GasLimitError(self.gasPool, gas)
+	}
+
+	rGas := new(big.Int).Set(gas)
+	rGas.Mul(rGas, price)
+
+	self.AddAmount(rGas)
+
+	return nil
+}
+
+func (self *StateObject) RefundGas(gas, price *big.Int) {
+	self.gasPool.Add(self.gasPool, gas)
+
+	rGas := new(big.Int).Set(gas)
+	rGas.Mul(rGas, price)
+
+	self.Amount.Sub(self.Amount, rGas)
+}
+
+func (self *StateObject) Copy() *StateObject {
+	stateObject := NewStateObject(self.Address())
+	stateObject.Amount.Set(self.Amount)
+	stateObject.CodeHash = ethutil.CopyBytes(self.CodeHash)
+	stateObject.Nonce = self.Nonce
+	if self.state != nil {
+		stateObject.state = self.state.Copy()
+	}
+	stateObject.Code = ethutil.CopyBytes(self.Code)
+	stateObject.initCode = ethutil.CopyBytes(self.initCode)
+	stateObject.storage = self.storage.Copy()
+	stateObject.gasPool.Set(self.gasPool)
+
+	return stateObject
+}
+
+func (self *StateObject) Set(stateObject *StateObject) {
+	*self = *stateObject
+}
+
+//
+// Attribute accessors
+//
+
+func (c *StateObject) State() *State {
+	return c.state
+}
+
+func (c *StateObject) N() *big.Int {
+	return big.NewInt(int64(c.Nonce))
+}
+
+// Returns the address of the contract/account
+func (c *StateObject) Address() []byte {
+	return c.address
+}
+
+// Returns the initialization Code
+func (c *StateObject) Init() Code {
+	return c.initCode
+}
+
+// Debug stuff
+func (self *StateObject) CreateOutputForDiff() {
+	fmt.Printf("%x %x %x %x\n", self.Address(), self.state.Root(), self.Amount.Bytes(), self.Nonce)
+	self.EachStorage(func(addr string, value *ethutil.Value) {
+		fmt.Printf("%x %x\n", addr, value.Bytes())
+	})
+}
+
+//
+// Encoding
+//
+
+// State object encoding methods
+func (c *StateObject) RlpEncode() []byte {
+	var root interface{}
+	if c.state != nil {
+		root = c.state.trie.Root
+	} else {
+		root = ""
+	}
+
+	return ethutil.Encode([]interface{}{c.Nonce, c.Amount, root, ethcrypto.Sha3Bin(c.Code)})
+}
+
+func (c *StateObject) RlpDecode(data []byte) {
+	decoder := ethutil.NewValueFromBytes(data)
+
+	c.Nonce = decoder.Get(0).Uint()
+	c.Amount = decoder.Get(1).BigInt()
+	c.state = NewState(ethtrie.NewTrie(ethutil.Config.Db, decoder.Get(2).Interface()))
+	c.storage = make(map[string]*ethutil.Value)
+	c.gasPool = new(big.Int)
+
+	c.CodeHash = decoder.Get(3).Bytes()
+
+	c.Code, _ = ethutil.Config.Db.Get(c.CodeHash)
+}
+
+// Storage change object. Used by the manifest for notifying changes to
+// the sub channels.
+type StorageState struct {
+	StateAddress []byte
+	Address      []byte
+	Value        *big.Int
+}
diff --git a/ethstate/state_test.go b/ethstate/state_test.go
new file mode 100644
index 000000000..cd13e80bc
--- /dev/null
+++ b/ethstate/state_test.go
@@ -0,0 +1,35 @@
+package ethstate
+
+import (
+	"github.com/ethereum/eth-go/ethdb"
+	"github.com/ethereum/eth-go/ethtrie"
+	"github.com/ethereum/eth-go/ethutil"
+	"testing"
+)
+
+var ZeroHash256 = make([]byte, 32)
+
+func TestSnapshot(t *testing.T) {
+	db, _ := ethdb.NewMemDatabase()
+	ethutil.ReadConfig(".ethtest", "/tmp/ethtest", "")
+	ethutil.Config.Db = db
+
+	state := NewState(ethtrie.NewTrie(db, ""))
+
+	stateObject := state.GetOrNewStateObject([]byte("aa"))
+
+	stateObject.SetStorage(ethutil.Big("0"), ethutil.NewValue(42))
+
+	snapshot := state.Copy()
+
+	stateObject = state.GetStateObject([]byte("aa"))
+	stateObject.SetStorage(ethutil.Big("0"), ethutil.NewValue(43))
+
+	state.Set(snapshot)
+
+	stateObject = state.GetStateObject([]byte("aa"))
+	res := stateObject.GetStorage(ethutil.Big("0"))
+	if !res.Cmp(ethutil.NewValue(42)) {
+		t.Error("Expected storage 0 to be 42", res)
+	}
+}