17f0b11942
1. fix typos 2. methods recevier of struct should be same 3. comments improve (cherry picked from commit 1ba979539582a00b7fd1a7c8a37a6852e59eac0d)
284 lines
7.8 KiB
Go
284 lines
7.8 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 core
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"math/big"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/common/math"
|
|
"github.com/ethereum/go-ethereum/core/vm"
|
|
"github.com/ethereum/go-ethereum/log"
|
|
"github.com/ethereum/go-ethereum/params"
|
|
)
|
|
|
|
var (
|
|
Big0 = big.NewInt(0)
|
|
errInsufficientBalanceForGas = errors.New("insufficient balance to pay for gas")
|
|
)
|
|
|
|
/*
|
|
The State Transitioning Model
|
|
|
|
A state transition is a change made when a transaction is applied to the current world state
|
|
The state transitioning model does all all the necessary work to work out a valid new state root.
|
|
|
|
1) Nonce handling
|
|
2) Pre pay gas
|
|
3) Create a new state object if the recipient is \0*32
|
|
4) Value transfer
|
|
== If contract creation ==
|
|
4a) Attempt to run transaction data
|
|
4b) If valid, use result as code for the new state object
|
|
== end ==
|
|
5) Run Script section
|
|
6) Derive new state root
|
|
*/
|
|
type StateTransition struct {
|
|
gp *GasPool
|
|
msg Message
|
|
gas uint64
|
|
gasPrice *big.Int
|
|
initialGas *big.Int
|
|
value *big.Int
|
|
data []byte
|
|
state vm.StateDB
|
|
|
|
evm *vm.EVM
|
|
}
|
|
|
|
// Message represents a message sent to a contract.
|
|
type Message interface {
|
|
From() common.Address
|
|
//FromFrontier() (common.Address, error)
|
|
To() *common.Address
|
|
|
|
GasPrice() *big.Int
|
|
Gas() *big.Int
|
|
Value() *big.Int
|
|
|
|
Nonce() uint64
|
|
CheckNonce() bool
|
|
Data() []byte
|
|
}
|
|
|
|
// IntrinsicGas computes the 'intrinsic gas' for a message
|
|
// with the given data.
|
|
//
|
|
// TODO convert to uint64
|
|
func IntrinsicGas(data []byte, contractCreation, homestead bool) *big.Int {
|
|
igas := new(big.Int)
|
|
if contractCreation && homestead {
|
|
igas.SetUint64(params.TxGasContractCreation)
|
|
} else {
|
|
igas.SetUint64(params.TxGas)
|
|
}
|
|
if len(data) > 0 {
|
|
var nz int64
|
|
for _, byt := range data {
|
|
if byt != 0 {
|
|
nz++
|
|
}
|
|
}
|
|
m := big.NewInt(nz)
|
|
m.Mul(m, new(big.Int).SetUint64(params.TxDataNonZeroGas))
|
|
igas.Add(igas, m)
|
|
m.SetInt64(int64(len(data)) - nz)
|
|
m.Mul(m, new(big.Int).SetUint64(params.TxDataZeroGas))
|
|
igas.Add(igas, m)
|
|
}
|
|
return igas
|
|
}
|
|
|
|
// NewStateTransition initialises and returns a new state transition object.
|
|
func NewStateTransition(evm *vm.EVM, msg Message, gp *GasPool) *StateTransition {
|
|
return &StateTransition{
|
|
gp: gp,
|
|
evm: evm,
|
|
msg: msg,
|
|
gasPrice: msg.GasPrice(),
|
|
initialGas: new(big.Int),
|
|
value: msg.Value(),
|
|
data: msg.Data(),
|
|
state: evm.StateDB,
|
|
}
|
|
}
|
|
|
|
// ApplyMessage computes the new state by applying the given message
|
|
// against the old state within the environment.
|
|
//
|
|
// ApplyMessage returns the bytes returned by any EVM execution (if it took place),
|
|
// the gas used (which includes gas refunds) and an error if it failed. An error always
|
|
// indicates a core error meaning that the message would always fail for that particular
|
|
// state and would never be accepted within a block.
|
|
func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool) ([]byte, *big.Int, error) {
|
|
st := NewStateTransition(evm, msg, gp)
|
|
|
|
ret, _, gasUsed, err := st.TransitionDb()
|
|
return ret, gasUsed, err
|
|
}
|
|
|
|
func (st *StateTransition) from() vm.AccountRef {
|
|
f := st.msg.From()
|
|
if !st.state.Exist(f) {
|
|
st.state.CreateAccount(f)
|
|
}
|
|
return vm.AccountRef(f)
|
|
}
|
|
|
|
func (st *StateTransition) to() vm.AccountRef {
|
|
if st.msg == nil {
|
|
return vm.AccountRef{}
|
|
}
|
|
to := st.msg.To()
|
|
if to == nil {
|
|
return vm.AccountRef{} // contract creation
|
|
}
|
|
|
|
reference := vm.AccountRef(*to)
|
|
if !st.state.Exist(*to) {
|
|
st.state.CreateAccount(*to)
|
|
}
|
|
return reference
|
|
}
|
|
|
|
func (st *StateTransition) useGas(amount uint64) error {
|
|
if st.gas < amount {
|
|
return vm.ErrOutOfGas
|
|
}
|
|
st.gas -= amount
|
|
|
|
return nil
|
|
}
|
|
|
|
func (st *StateTransition) buyGas() error {
|
|
mgas := st.msg.Gas()
|
|
if mgas.BitLen() > 64 {
|
|
return vm.ErrOutOfGas
|
|
}
|
|
|
|
mgval := new(big.Int).Mul(mgas, st.gasPrice)
|
|
|
|
var (
|
|
state = st.state
|
|
sender = st.from()
|
|
)
|
|
if state.GetBalance(sender.Address()).Cmp(mgval) < 0 {
|
|
return errInsufficientBalanceForGas
|
|
}
|
|
if err := st.gp.SubGas(mgas); err != nil {
|
|
return err
|
|
}
|
|
st.gas += mgas.Uint64()
|
|
|
|
st.initialGas.Set(mgas)
|
|
state.SubBalance(sender.Address(), mgval)
|
|
return nil
|
|
}
|
|
|
|
func (st *StateTransition) preCheck() error {
|
|
msg := st.msg
|
|
sender := st.from()
|
|
|
|
// Make sure this transaction's nonce is correct
|
|
if msg.CheckNonce() {
|
|
if n := st.state.GetNonce(sender.Address()); n != msg.Nonce() {
|
|
return fmt.Errorf("invalid nonce: have %d, expected %d", msg.Nonce(), n)
|
|
}
|
|
}
|
|
return st.buyGas()
|
|
}
|
|
|
|
// TransitionDb will transition the state by applying the current message and returning the result
|
|
// including the required gas for the operation as well as the used gas. It returns an error if it
|
|
// failed. An error indicates a consensus issue.
|
|
func (st *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *big.Int, err error) {
|
|
if err = st.preCheck(); err != nil {
|
|
return
|
|
}
|
|
msg := st.msg
|
|
sender := st.from() // err checked in preCheck
|
|
|
|
homestead := st.evm.ChainConfig().IsHomestead(st.evm.BlockNumber)
|
|
contractCreation := msg.To() == nil
|
|
|
|
// Pay intrinsic gas
|
|
// TODO convert to uint64
|
|
intrinsicGas := IntrinsicGas(st.data, contractCreation, homestead)
|
|
if intrinsicGas.BitLen() > 64 {
|
|
return nil, nil, nil, vm.ErrOutOfGas
|
|
}
|
|
if err = st.useGas(intrinsicGas.Uint64()); err != nil {
|
|
return nil, nil, nil, err
|
|
}
|
|
|
|
var (
|
|
evm = st.evm
|
|
// vm errors do not effect consensus and are therefor
|
|
// not assigned to err, except for insufficient balance
|
|
// error.
|
|
vmerr error
|
|
)
|
|
if contractCreation {
|
|
ret, _, st.gas, vmerr = evm.Create(sender, st.data, st.gas, st.value)
|
|
} else {
|
|
// Increment the nonce for the next transaction
|
|
st.state.SetNonce(sender.Address(), st.state.GetNonce(sender.Address())+1)
|
|
ret, st.gas, vmerr = evm.Call(sender, st.to().Address(), st.data, st.gas, st.value)
|
|
}
|
|
if vmerr != nil {
|
|
log.Debug("VM returned with error", "err", err)
|
|
// The only possible consensus-error would be if there wasn't
|
|
// sufficient balance to make the transfer happen. The first
|
|
// balance transfer may never fail.
|
|
if vmerr == vm.ErrInsufficientBalance {
|
|
return nil, nil, nil, vmerr
|
|
}
|
|
}
|
|
requiredGas = new(big.Int).Set(st.gasUsed())
|
|
|
|
st.refundGas()
|
|
st.state.AddBalance(st.evm.Coinbase, new(big.Int).Mul(st.gasUsed(), st.gasPrice))
|
|
|
|
return ret, requiredGas, st.gasUsed(), err
|
|
}
|
|
|
|
func (st *StateTransition) refundGas() {
|
|
// Return eth for remaining gas to the sender account,
|
|
// exchanged at the original rate.
|
|
sender := st.from() // err already checked
|
|
remaining := new(big.Int).Mul(new(big.Int).SetUint64(st.gas), st.gasPrice)
|
|
st.state.AddBalance(sender.Address(), remaining)
|
|
|
|
// Apply refund counter, capped to half of the used gas.
|
|
uhalf := remaining.Div(st.gasUsed(), common.Big2)
|
|
refund := math.BigMin(uhalf, st.state.GetRefund())
|
|
st.gas += refund.Uint64()
|
|
|
|
st.state.AddBalance(sender.Address(), refund.Mul(refund, st.gasPrice))
|
|
|
|
// Also return remaining gas to the block gas counter so it is
|
|
// available for the next transaction.
|
|
st.gp.AddGas(new(big.Int).SetUint64(st.gas))
|
|
}
|
|
|
|
func (st *StateTransition) gasUsed() *big.Int {
|
|
return new(big.Int).Sub(st.initialGas, new(big.Int).SetUint64(st.gas))
|
|
}
|