1 files changed, 194 insertions, 0 deletions
diff --git a/ethchain/state_object.go b/ethchain/state_object.go
new file mode 100644
index 000000000..617646077
--- /dev/null
+++ b/ethchain/state_object.go
@@ -0,0 +1,194 @@
+package ethchain
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+type StateObject struct {
+	// Address of the object
+	address []byte
+	// Shared attributes
+	Amount *big.Int
+	Nonce  uint64
+	// Contract related attributes
+	state      *State
+	script     []byte
+	initScript []byte
+}
+
+// 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() {
+		// FIXME
+		addr := tx.Hash()[12:]
+
+		value := tx.Value
+		contract := NewContract(addr, value, []byte(""))
+		state.UpdateStateObject(contract)
+
+		contract.script = tx.Data
+		contract.initScript = tx.Init
+
+		state.UpdateStateObject(contract)
+
+		return contract
+	}
+
+	return nil
+}
+
+func NewContract(address []byte, Amount *big.Int, root []byte) *StateObject {
+	contract := &StateObject{address: address, Amount: Amount, Nonce: 0}
+	contract.state = NewState(ethutil.NewTrie(ethutil.Config.Db, string(root)))
+
+	return contract
+}
+
+// Returns a newly created account
+func NewAccount(address []byte, amount *big.Int) *StateObject {
+	account := &StateObject{address: address, Amount: amount, Nonce: 0}
+
+	return account
+}
+
+func NewStateObjectFromBytes(address, data []byte) *StateObject {
+	object := &StateObject{address: address}
+	object.RlpDecode(data)
+
+	return object
+}
+
+func (c *StateObject) State() *State {
+	return c.state
+}
+
+func (c *StateObject) N() *big.Int {
+	return big.NewInt(int64(c.Nonce))
+}
+
+func (c *StateObject) Addr(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 (c *StateObject) SetMem(num *big.Int, val *ethutil.Value) {
+	addr := ethutil.BigToBytes(num, 256)
+	c.SetAddr(addr, val)
+}
+
+func (c *StateObject) GetMem(num *big.Int) *ethutil.Value {
+	nb := ethutil.BigToBytes(num, 256)
+
+	return c.Addr(nb)
+}
+
+func (c *StateObject) GetInstr(pc *big.Int) *ethutil.Value {
+	if int64(len(c.script)-1) < pc.Int64() {
+		return ethutil.NewValue(0)
+	}
+
+	return ethutil.NewValueFromBytes([]byte{c.script[pc.Int64()]})
+}
+
+// Return the gas back to the origin. Used by the Virtual machine or Closures
+func (c *StateObject) ReturnGas(gas, price *big.Int, state *State) {
+	remainder := new(big.Int).Mul(gas, price)
+	c.AddAmount(remainder)
+}
+
+func (c *StateObject) AddAmount(amount *big.Int) {
+	c.SetAmount(new(big.Int).Add(c.Amount, amount))
+}
+
+func (c *StateObject) SubAmount(amount *big.Int) {
+	c.SetAmount(new(big.Int).Sub(c.Amount, amount))
+}
+
+func (c *StateObject) SetAmount(amount *big.Int) {
+	c.Amount = amount
+}
+
+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
+}
+
+// Returns the address of the contract/account
+func (c *StateObject) Address() []byte {
+	return c.address
+}
+
+// Returns the main script body
+func (c *StateObject) Script() []byte {
+	return c.script
+}
+
+// Returns the initialization script
+func (c *StateObject) Init() []byte {
+	return c.initScript
+}
+
+// State object encoding methods
+func (c *StateObject) RlpEncode() []byte {
+	var root interface{}
+	if c.state != nil {
+		root = c.state.trie.Root
+	} else {
+		root = nil
+	}
+	return ethutil.Encode([]interface{}{c.Amount, c.Nonce, root, c.script})
+}
+
+func (c *StateObject) RlpDecode(data []byte) {
+	decoder := ethutil.NewValueFromBytes(data)
+
+	c.Amount = decoder.Get(0).BigInt()
+	c.Nonce = decoder.Get(1).Uint()
+	c.state = NewState(ethutil.NewTrie(ethutil.Config.Db, decoder.Get(2).Interface()))
+	c.script = decoder.Get(3).Bytes()
+}
+
+// The cached state and state object cache are helpers which will give you somewhat
+// control over the nonce. When creating new transactions you're interested in the 'next'
+// nonce rather than the current nonce. This to avoid creating invalid-nonce transactions.
+type StateObjectCache struct {
+	cachedObjects map[string]*CachedStateObject
+}
+
+func NewStateObjectCache() *StateObjectCache {
+	return &StateObjectCache{cachedObjects: make(map[string]*CachedStateObject)}
+}
+
+func (s *StateObjectCache) Add(addr []byte, object *StateObject) *CachedStateObject {
+	state := &CachedStateObject{Nonce: object.Nonce, Object: object}
+	s.cachedObjects[string(addr)] = state
+
+	return state
+}
+
+func (s *StateObjectCache) Get(addr []byte) *CachedStateObject {
+	return s.cachedObjects[string(addr)]
+}
+
+type CachedStateObject struct {
+	Nonce  uint64
+	Object *StateObject
+}
+
+type StorageState struct {
+	StateAddress []byte
+	Address      []byte
+	Value        *big.Int
+}