tzhash/gogf127/gf127_test.go
Evgenii Stratonikov c5fb08aece Speed up gogf127.Mul()
Cache results of the shift. Also add test for checking if
implementation can work when result is one of the arguments.
2019-10-11 11:50:33 +03:00

125 lines
2.6 KiB
Go

package gogf127
import (
"testing"
"github.com/stretchr/testify/require"
)
const maxUint64 = ^uint64(0)
func TestAdd(t *testing.T) {
var (
a = Random()
b = Random()
e = &GF127{a[0] ^ b[0], a[1] ^ b[1]}
c = new(GF127)
)
Add(a, b, c)
require.Equal(t, e, c)
}
var testCasesMul = [][3]*GF127{
// (x+1)*(x^63+x^62+...+1) == x^64+1
{&GF127{3, 0}, &GF127{maxUint64, 0}, &GF127{1, 1}},
// x^126 * x^2 == x^128 == x^64 + x
{&GF127{0, 1 << 62}, &GF127{4, 0}, &GF127{2, 1}},
// (x^64+x^63+1) * (x^64+x) == x^128+x^65+x^127+x^64+x^64+x == x^65+x^64+x^63+1
{&GF127{1 + 1<<63, 1}, &GF127{2, 1}, &GF127{0x8000000000000001, 3}},
}
func TestMul(t *testing.T) {
c := new(GF127)
for _, tc := range testCasesMul {
Mul(tc[0], tc[1], c)
require.Equal(t, tc[2], c)
}
}
func TestMulInPlace(t *testing.T) {
for _, tc := range testCasesMul {
a := *tc[0]
b := *tc[1]
Mul(&a, &b, &b)
require.Equal(t, a, *tc[0])
require.Equal(t, b, *tc[2])
b = *tc[1]
Mul(&a, &b, &a)
require.Equal(t, b, *tc[1])
require.Equal(t, a, *tc[2])
}
}
var testCasesMul10 = [][2]*GF127{
{&GF127{123, 0}, &GF127{246, 0}},
{&GF127{maxUint64, 2}, &GF127{maxUint64 - 1, 5}},
{&GF127{0, maxUint64 >> 1}, &GF127{1 + 1<<63, maxUint64>>1 - 1}},
}
func TestMul10(t *testing.T) {
c := new(GF127)
for _, tc := range testCasesMul10 {
Mul10(tc[0], c)
require.Equal(t, tc[1], c)
}
}
var testCasesMul11 = [][2]*GF127{
{&GF127{123, 0}, &GF127{141, 0}},
{&GF127{maxUint64, 2}, &GF127{1, 7}},
{&GF127{0, maxUint64 >> 1}, &GF127{1 + 1<<63, 1}},
}
func TestMul11(t *testing.T) {
c := new(GF127)
for _, tc := range testCasesMul11 {
Mul11(tc[0], c)
require.Equal(t, tc[1], c)
}
}
var testCasesInv = [][2]*GF127{
{&GF127{1, 0}, &GF127{1, 0}},
{&GF127{3, 0}, &GF127{msb64, ^msb64}},
{&GF127{54321, 12345}, &GF127{8230555108620784737, 3929873967650665114}},
}
func TestInv(t *testing.T) {
var a, b, c = new(GF127), new(GF127), new(GF127)
for _, tc := range testCasesInv {
Inv(tc[0], c)
require.Equal(t, tc[1], c)
}
for i := 0; i < 3; i++ {
// 0 has no inverse
if a = Random(); a.Equals(&GF127{0, 0}) {
continue
}
Inv(a, b)
Mul(a, b, c)
require.Equal(t, &GF127{1, 0}, c)
}
}
func TestGF127_MarshalBinary(t *testing.T) {
a := New(0xFF, 0xEE)
data, err := a.MarshalBinary()
require.NoError(t, err)
require.Equal(t, data, []byte{0, 0, 0, 0, 0, 0, 0, 0xEE, 0, 0, 0, 0, 0, 0, 0, 0xFF})
a = Random()
data, err = a.MarshalBinary()
require.NoError(t, err)
b := new(GF127)
err = b.UnmarshalBinary(data)
require.NoError(t, err)
require.Equal(t, a, b)
err = b.UnmarshalBinary([]byte{0, 1, 2, 3})
require.Error(t, err)
}