// Copyright 2017 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 math
import (
"bytes"
"encoding/hex"
"math/big"
"testing"
"github.com/dexon-foundation/dexon/common"
)
func TestHexOrDecimal256(t *testing.T) {
tests := []struct {
input string
num *big.Int
ok bool
}{
{"", big.NewInt(0), true},
{"0", big.NewInt(0), true},
{"0x0", big.NewInt(0), true},
{"12345678", big.NewInt(12345678), true},
{"0x12345678", big.NewInt(0x12345678), true},
{"0X12345678", big.NewInt(0x12345678), true},
// Tests for leading zero behaviour:
{"0123456789", big.NewInt(123456789), true}, // note: not octal
{"00", big.NewInt(0), true},
{"0x00", big.NewInt(0), true},
{"0x012345678abc", big.NewInt(0x12345678abc), true},
// Invalid syntax:
{"abcdef", nil, false},
{"0xgg", nil, false},
// Larger than 256 bits:
{"115792089237316195423570985008687907853269984665640564039457584007913129639936", nil, false},
}
for _, test := range tests {
var num HexOrDecimal256
err := num.UnmarshalText([]byte(test.input))
if (err == nil) != test.ok {
t.Errorf("ParseBig(%q) -> (err == nil) == %t, want %t", test.input, err == nil, test.ok)
continue
}
if test.num != nil && (*big.Int)(&num).Cmp(test.num) != 0 {
t.Errorf("ParseBig(%q) -> %d, want %d", test.input, (*big.Int)(&num), test.num)
}
}
}
func TestMustParseBig256(t *testing.T) {
defer func() {
if recover() == nil {
t.Error("MustParseBig should've panicked")
}
}()
MustParseBig256("ggg")
}
func TestBigMax(t *testing.T) {
a := big.NewInt(10)
b := big.NewInt(5)
max1 := BigMax(a, b)
if max1 != a {
t.Errorf("Expected %d got %d", a, max1)
}
max2 := BigMax(b, a)
if max2 != a {
t.Errorf("Expected %d got %d", a, max2)
}
}
func TestBigMin(t *testing.T) {
a := big.NewInt(10)
b := big.NewInt(5)
min1 := BigMin(a, b)
if min1 != b {
t.Errorf("Expected %d got %d", b, min1)
}
min2 := BigMin(b, a)
if min2 != b {
t.Errorf("Expected %d got %d", b, min2)
}
}
func TestFirstBigSet(t *testing.T) {
tests := []struct {
num *big.Int
ix int
}{
{big.NewInt(0), 0},
{big.NewInt(1), 0},
{big.NewInt(2), 1},
{big.NewInt(0x100), 8},
}
for _, test := range tests {
if ix := FirstBitSet(test.num); ix != test.ix {
t.Errorf("FirstBitSet(b%b) = %d, want %d", test.num, ix, test.ix)
}
}
}
func TestPaddedBigBytes(t *testing.T) {
tests := []struct {
num *big.Int
n int
result []byte
}{
{num: big.NewInt(0), n: 4, result: []byte{0, 0, 0, 0}},
{num: big.NewInt(1), n: 4, result: []byte{0, 0, 0, 1}},
{num: big.NewInt(512), n: 4, result: []byte{0, 0, 2, 0}},
{num: BigPow(2, 32), n: 4, result: []byte{1, 0, 0, 0, 0}},
}
for _, test := range tests {
if result := PaddedBigBytes(test.num, test.n); !bytes.Equal(result, test.result) {
t.Errorf("PaddedBigBytes(%d, %d) = %v, want %v", test.num, test.n, result, test.result)
}
}
}
func BenchmarkPaddedBigBytesLargePadding(b *testing.B) {
bigint := MustParseBig256("123456789123456789123456789123456789")
for i := 0; i < b.N; i++ {
PaddedBigBytes(bigint, 200)
}
}
func BenchmarkPaddedBigBytesSmallPadding(b *testing.B) {
bigint := MustParseBig256("0x18F8F8F1000111000110011100222004330052300000000000000000FEFCF3CC")
for i := 0; i < b.N; i++ {
PaddedBigBytes(bigint, 5)
}
}
func BenchmarkPaddedBigBytesSmallOnePadding(b *testing.B) {
bigint := MustParseBig256("0x18F8F8F1000111000110011100222004330052300000000000000000FEFCF3CC")
for i := 0; i < b.N; i++ {
PaddedBigBytes(bigint, 32)
}
}
func BenchmarkByteAtBrandNew(b *testing.B) {
bigint := MustParseBig256("0x18F8F8F1000111000110011100222004330052300000000000000000FEFCF3CC")
for i := 0; i < b.N; i++ {
bigEndianByteAt(bigint, 15)
}
}
func BenchmarkByteAt(b *testing.B) {
bigint := MustParseBig256("0x18F8F8F1000111000110011100222004330052300000000000000000FEFCF3CC")
for i := 0; i < b.N; i++ {
bigEndianByteAt(bigint, 15)
}
}
func BenchmarkByteAtOld(b *testing.B) {
bigint := MustParseBig256("0x18F8F8F1000111000110011100222004330052300000000000000000FEFCF3CC")
for i := 0; i < b.N; i++ {
PaddedBigBytes(bigint, 32)
}
}
func TestReadBits(t *testing.T) {
check := func(input string) {
want, _ := hex.DecodeString(input)
int, _ := new(big.Int).SetString(input, 16)
buf := make([]byte, len(want))
ReadBits(int, buf)
if !bytes.Equal(buf, want) {
t.Errorf("have: %x\nwant: %x", buf, want)
}
}
check("000000000000000000000000000000000000000000000000000000FEFCF3F8F0")
check("0000000000012345000000000000000000000000000000000000FEFCF3F8F0")
check("18F8F8F1000111000110011100222004330052300000000000000000FEFCF3F8F0")
}
func TestU256(t *testing.T) {
tests := []struct{ x, y *big.Int }{
{x: big.NewInt(0), y: big.NewInt(0)},
{x: big.NewInt(1), y: big.NewInt(1)},
{x: BigPow(2, 255), y: BigPow(2, 255)},
{x: BigPow(2, 256), y: big.NewInt(0)},
{x: new(big.Int).Add(BigPow(2, 256), big.NewInt(1)), y: big.NewInt(1)},
// negative values
{x: big.NewInt(-1), y: new(big.Int).Sub(BigPow(2, 256), big.NewInt(1))},
{x: big.NewInt(-2), y: new(big.Int).Sub(BigPow(2, 256), big.NewInt(2))},
{x: BigPow(2, -255), y: big.NewInt(1)},
}
for _, test := range tests {
if y := U256(new(big.Int).Set(test.x)); y.Cmp(test.y) != 0 {
t.Errorf("U256(%x) = %x, want %x", test.x, y, test.y)
}
}
}
func TestBigEndianByteAt(t *testing.T) {
tests := []struct {
x string
y int
exp byte
}{
{"00", 0, 0x00},
{"01", 1, 0x00},
{"00", 1, 0x00},
{"01", 0, 0x01},
{"0000000000000000000000000000000000000000000000000000000000102030", 0, 0x30},
{"0000000000000000000000000000000000000000000000000000000000102030", 1, 0x20},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 31, 0xAB},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 32, 0x00},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 500, 0x00},
}
for _, test := range tests {
v := new(big.Int).SetBytes(common.Hex2Bytes(test.x))
actual := bigEndianByteAt(v, test.y)
if actual != test.exp {
t.Fatalf("Expected [%v] %v:th byte to be %v, was %v.", test.x, test.y, test.exp, actual)
}
}
}
func TestLittleEndianByteAt(t *testing.T) {
tests := []struct {
x string
y int
exp byte
}{
{"00", 0, 0x00},
{"01", 1, 0x00},
{"00", 1, 0x00},
{"01", 0, 0x00},
{"0000000000000000000000000000000000000000000000000000000000102030", 0, 0x00},
{"0000000000000000000000000000000000000000000000000000000000102030", 1, 0x00},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 31, 0x00},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 32, 0x00},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 0, 0xAB},
{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 1, 0xCD},
{"00CDEF090807060504030201ffffffffffffffffffffffffffffffffffffffff", 0, 0x00},
{"00CDEF090807060504030201ffffffffffffffffffffffffffffffffffffffff", 1, 0xCD},
{"0000000000000000000000000000000000000000000000000000000000102030", 31, 0x30},
{"0000000000000000000000000000000000000000000000000000000000102030", 30, 0x20},
{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 32, 0x0},
{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 31, 0xFF},
{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 0xFFFF, 0x0},
}
for _, test := range tests {
v := new(big.Int).SetBytes(common.Hex2Bytes(test.x))
actual := Byte(v, 32, test.y)
if actual != test.exp {
t.Fatalf("Expected [%v] %v:th byte to be %v, was %v.", test.x, test.y, test.exp, actual)
}
}
}
func TestS256(t *testing.T) {
tests := []struct{ x, y *big.Int }{
{x: big.NewInt(0), y: big.NewInt(0)},
{x: big.NewInt(1), y: big.NewInt(1)},
{x: big.NewInt(2), y: big.NewInt(2)},
{
x: new(big.Int).Sub(BigPow(2, 255), big.NewInt(1)),
y: new(big.Int).Sub(BigPow(2, 255), big.NewInt(1)),
},
{
x: BigPow(2, 255),
y: new(big.Int).Neg(BigPow(2, 255)),
},
{
x: new(big.Int).Sub(BigPow(2, 256), big.NewInt(1)),
y: big.NewInt(-1),
},
{
x: new(big.Int).Sub(BigPow(2, 256), big.NewInt(2)),
y: big.NewInt(-2),
},
}
for _, test := range tests {
if y := S256(test.x); y.Cmp(test.y) != 0 {
t.Errorf("S256(%x) = %x, want %x", test.x, y, test.y)
}
}
}
func TestExp(t *testing.T) {
tests := []struct{ base, exponent, result *big.Int }{
{base: big.NewInt(0), exponent: big.NewInt(0), result: big.NewInt(1)},
{base: big.NewInt(1), exponent: big.NewInt(0), result: big.NewInt(1)},
{base: big.NewInt(1), exponent: big.NewInt(1), result: big.NewInt(1)},
{base: big.NewInt(1), exponent: big.NewInt(2), result: big.NewInt(1)},
{base: big.NewInt(3), exponent: big.NewInt(144), result: MustParseBig256("507528786056415600719754159741696356908742250191663887263627442114881")},
{base: big.NewInt(2), exponent: big.NewInt(255), result: MustParseBig256("57896044618658097711785492504343953926634992332820282019728792003956564819968")},
}
for _, test := range tests {
if result := Exp(test.base, test.exponent); result.Cmp(test.result) != 0 {
t.Errorf("Exp(%d, %d) = %d, want %d", test.base, test.exponent, result, test.result)
}
}
}
