mirror of
https://gitlab.com/pulsechaincom/erigon-pulse.git
synced 2024-12-24 12:37:16 +00:00
154 lines
3.2 KiB
Go
154 lines
3.2 KiB
Go
// Copyright 2014 The go-ethereum Authors
|
|
// This file is part of go-ethereum.
|
|
//
|
|
// go-ethereum 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.
|
|
//
|
|
// go-ethereum 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 go-ethereum. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package common
|
|
|
|
import "math/big"
|
|
|
|
// Common big integers often used
|
|
var (
|
|
Big1 = big.NewInt(1)
|
|
Big2 = big.NewInt(2)
|
|
Big3 = big.NewInt(3)
|
|
Big0 = big.NewInt(0)
|
|
BigTrue = Big1
|
|
BigFalse = Big0
|
|
Big32 = big.NewInt(32)
|
|
Big256 = big.NewInt(0xff)
|
|
Big257 = big.NewInt(257)
|
|
MaxBig = String2Big("0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")
|
|
)
|
|
|
|
// Big pow
|
|
//
|
|
// Returns the power of two big integers
|
|
func BigPow(a, b int) *big.Int {
|
|
c := new(big.Int)
|
|
c.Exp(big.NewInt(int64(a)), big.NewInt(int64(b)), big.NewInt(0))
|
|
|
|
return c
|
|
}
|
|
|
|
// Big
|
|
//
|
|
// Shortcut for new(big.Int).SetString(..., 0)
|
|
func Big(num string) *big.Int {
|
|
n := new(big.Int)
|
|
n.SetString(num, 0)
|
|
|
|
return n
|
|
}
|
|
|
|
// Bytes2Big
|
|
//
|
|
func BytesToBig(data []byte) *big.Int {
|
|
n := new(big.Int)
|
|
n.SetBytes(data)
|
|
|
|
return n
|
|
}
|
|
func Bytes2Big(data []byte) *big.Int { return BytesToBig(data) }
|
|
func BigD(data []byte) *big.Int { return BytesToBig(data) }
|
|
|
|
func String2Big(num string) *big.Int {
|
|
n := new(big.Int)
|
|
n.SetString(num, 0)
|
|
return n
|
|
}
|
|
|
|
func BitTest(num *big.Int, i int) bool {
|
|
return num.Bit(i) > 0
|
|
}
|
|
|
|
// To256
|
|
//
|
|
// "cast" the big int to a 256 big int (i.e., limit to)
|
|
var tt256 = new(big.Int).Lsh(big.NewInt(1), 256)
|
|
var tt256m1 = new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(1))
|
|
var tt255 = new(big.Int).Lsh(big.NewInt(1), 255)
|
|
|
|
func U256(x *big.Int) *big.Int {
|
|
//if x.Cmp(Big0) < 0 {
|
|
// return new(big.Int).Add(tt256, x)
|
|
// }
|
|
|
|
x.And(x, tt256m1)
|
|
|
|
return x
|
|
}
|
|
|
|
func S256(x *big.Int) *big.Int {
|
|
if x.Cmp(tt255) < 0 {
|
|
return x
|
|
} else {
|
|
// We don't want to modify x, ever
|
|
return new(big.Int).Sub(x, tt256)
|
|
}
|
|
}
|
|
|
|
func FirstBitSet(v *big.Int) int {
|
|
for i := 0; i < v.BitLen(); i++ {
|
|
if v.Bit(i) > 0 {
|
|
return i
|
|
}
|
|
}
|
|
|
|
return v.BitLen()
|
|
}
|
|
|
|
// Big to bytes
|
|
//
|
|
// Returns the bytes of a big integer with the size specified by **base**
|
|
// Attempts to pad the byte array with zeros.
|
|
func BigToBytes(num *big.Int, base int) []byte {
|
|
ret := make([]byte, base/8)
|
|
|
|
if len(num.Bytes()) > base/8 {
|
|
return num.Bytes()
|
|
}
|
|
|
|
return append(ret[:len(ret)-len(num.Bytes())], num.Bytes()...)
|
|
}
|
|
|
|
// Big copy
|
|
//
|
|
// Creates a copy of the given big integer
|
|
func BigCopy(src *big.Int) *big.Int {
|
|
return new(big.Int).Set(src)
|
|
}
|
|
|
|
// Big max
|
|
//
|
|
// Returns the maximum size big integer
|
|
func BigMax(x, y *big.Int) *big.Int {
|
|
if x.Cmp(y) < 0 {
|
|
return y
|
|
}
|
|
|
|
return x
|
|
}
|
|
|
|
// Big min
|
|
//
|
|
// Returns the minimum size big integer
|
|
func BigMin(x, y *big.Int) *big.Int {
|
|
if x.Cmp(y) > 0 {
|
|
return y
|
|
}
|
|
|
|
return x
|
|
}
|