125 lines
3.5 KiB
Go
125 lines
3.5 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 vm
|
|
|
|
import (
|
|
"math"
|
|
"math/big"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/params"
|
|
)
|
|
|
|
// Global Debug flag indicating Debug VM (full logging)
|
|
var Debug bool
|
|
|
|
var GenerateStructLogs bool = false
|
|
|
|
// Type is the VM type accepted by **NewVm**
|
|
type Type byte
|
|
|
|
const (
|
|
StdVmTy Type = iota // Default standard VM
|
|
JitVmTy // LLVM JIT VM
|
|
MaxVmTy
|
|
)
|
|
|
|
var (
|
|
Pow256 = common.BigPow(2, 256) // Pow256 is 2**256
|
|
|
|
U256 = common.U256 // Shortcut to common.U256
|
|
S256 = common.S256 // Shortcut to common.S256
|
|
|
|
Zero = common.Big0 // Shortcut to common.Big0
|
|
One = common.Big1 // Shortcut to common.Big1
|
|
|
|
max = big.NewInt(math.MaxInt64) // Maximum 64 bit integer
|
|
)
|
|
|
|
// calculates the memory size required for a step
|
|
func calcMemSize(off, l *big.Int) *big.Int {
|
|
if l.Cmp(common.Big0) == 0 {
|
|
return common.Big0
|
|
}
|
|
|
|
return new(big.Int).Add(off, l)
|
|
}
|
|
|
|
// calculates the quadratic gas
|
|
func quadMemGas(mem *Memory, newMemSize, gas *big.Int) {
|
|
if newMemSize.Cmp(common.Big0) > 0 {
|
|
newMemSizeWords := toWordSize(newMemSize)
|
|
newMemSize.Mul(newMemSizeWords, u256(32))
|
|
|
|
if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 {
|
|
// be careful reusing variables here when changing.
|
|
// The order has been optimised to reduce allocation
|
|
oldSize := toWordSize(big.NewInt(int64(mem.Len())))
|
|
pow := new(big.Int).Exp(oldSize, common.Big2, Zero)
|
|
linCoef := oldSize.Mul(oldSize, params.MemoryGas)
|
|
quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv)
|
|
oldTotalFee := new(big.Int).Add(linCoef, quadCoef)
|
|
|
|
pow.Exp(newMemSizeWords, common.Big2, Zero)
|
|
linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas)
|
|
quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv)
|
|
newTotalFee := linCoef.Add(linCoef, quadCoef)
|
|
|
|
fee := newTotalFee.Sub(newTotalFee, oldTotalFee)
|
|
gas.Add(gas, fee)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Simple helper
|
|
func u256(n int64) *big.Int {
|
|
return big.NewInt(n)
|
|
}
|
|
|
|
// Mainly used for print variables and passing to Print*
|
|
func toValue(val *big.Int) interface{} {
|
|
// Let's assume a string on right padded zero's
|
|
b := val.Bytes()
|
|
if b[0] != 0 && b[len(b)-1] == 0x0 && b[len(b)-2] == 0x0 {
|
|
return string(b)
|
|
}
|
|
|
|
return val
|
|
}
|
|
|
|
// getData returns a slice from the data based on the start and size and pads
|
|
// up to size with zero's. This function is overflow safe.
|
|
func getData(data []byte, start, size *big.Int) []byte {
|
|
dlen := big.NewInt(int64(len(data)))
|
|
|
|
s := common.BigMin(start, dlen)
|
|
e := common.BigMin(new(big.Int).Add(s, size), dlen)
|
|
return common.RightPadBytes(data[s.Uint64():e.Uint64()], int(size.Uint64()))
|
|
}
|
|
|
|
// useGas attempts to subtract the amount of gas and returns whether it was
|
|
// successful
|
|
func useGas(gas, amount *big.Int) bool {
|
|
if gas.Cmp(amount) < 0 {
|
|
return false
|
|
}
|
|
|
|
// Sub the amount of gas from the remaining
|
|
gas.Sub(gas, amount)
|
|
return true
|
|
}
|