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
}
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) 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) State() *State {
return c.state
}
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()]})
}
func (c *StateObject) SetMem(num *big.Int, val *ethutil.Value) {
addr := ethutil.BigToBytes(num, 256)
c.state.trie.Update(string(addr), string(val.Encode()))
}
// 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.Amount.Add(c.Amount, amount)
}
func (c *StateObject) SubAmount(amount *big.Int) {
c.Amount.Sub(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()
}
// 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
}
// 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
}
