path: root/state/state_object.go

package state

import (
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/ethtrie"
    "github.com/ethereum/go-ethereum/ethutil"
)

type Code []byte

func (self Code) String() string {
    return string(self) //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
    balance  *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()
}

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, balance: new(big.Int), gasPool: new(big.Int)}
    object.State = New(ethtrie.New(ethutil.Config.Db, ""))
    object.storage = make(Storage)
    object.gasPool = new(big.Int)

    return object
}

func NewContract(address []byte, balance *big.Int, root []byte) *StateObject {
    contract := NewStateObject(address)
    contract.balance = balance
    contract.State = New(ethtrie.New(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.balance)
}

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.GetState(key.Bytes())
}
func (self *StateObject) SetStorage(key *big.Int, value *ethutil.Value) {
    self.SetState(key.Bytes(), value)
}

func (self *StateObject) Storage() map[string]*ethutil.Value {
    return self.storage
}

func (self *StateObject) GetState(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
}

func (self *StateObject) SetState(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) AddBalance(amount *big.Int) {
    c.SetBalance(new(big.Int).Add(c.balance, amount))

    statelogger.Debugf("%x: #%d %v (+ %v)\n", c.Address(), c.Nonce, c.balance, amount)
}
func (c *StateObject) AddAmount(amount *big.Int) { c.AddBalance(amount) }

func (c *StateObject) SubBalance(amount *big.Int) {
    c.SetBalance(new(big.Int).Sub(c.balance, amount))

    statelogger.Debugf("%x: #%d %v (- %v)\n", c.Address(), c.Nonce, c.balance, amount)
}
func (c *StateObject) SubAmount(amount *big.Int) { c.SubBalance(amount) }

func (c *StateObject) SetBalance(amount *big.Int) {
    c.balance = amount
}

func (self *StateObject) Balance() *big.Int { return self.balance }

//
// 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.balance) > 0 {
        return fmt.Errorf("insufficient amount: %v, %v", c.balance, 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.balance.Sub(self.balance, rGas)
}

func (self *StateObject) Copy() *StateObject {
    stateObject := NewStateObject(self.Address())
    stateObject.balance.Set(self.balance)
    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)
    stateObject.remove = self.remove

    return stateObject
}

func (self *StateObject) Set(stateObject *StateObject) {
    *self = *stateObject
}

//
// Attribute accessors
//

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
}

// To satisfy ClosureRef
func (self *StateObject) Object() *StateObject {
    return self
}

// Debug stuff
func (self *StateObject) CreateOutputForDiff() {
    fmt.Printf("%x %x %x %x\n", self.Address(), self.State.Root(), self.balance.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.balance, root, c.CodeHash()})
}

func (c *StateObject) CodeHash() ethutil.Bytes {
    var codeHash []byte
    if len(c.Code) > 0 {
        codeHash = crypto.Sha3(c.Code)
    }

    return codeHash
}

func (c *StateObject) RlpDecode(data []byte) {
    decoder := ethutil.NewValueFromBytes(data)

    c.Nonce = decoder.Get(0).Uint()
    c.balance = decoder.Get(1).BigInt()
    c.State = New(ethtrie.New(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
}