restic/chunker/polynomials_test.go

351 lines
6.2 KiB
Go

package chunker_test
import (
"strconv"
"testing"
"github.com/restic/restic/chunker"
)
var polAddTests = []struct {
x, y chunker.Pol
sum chunker.Pol
}{
{23, 16, 23 ^ 16},
{0x9a7e30d1e855e0a0, 0x670102a1f4bcd414, 0xfd7f32701ce934b4},
{0x9a7e30d1e855e0a0, 0x9a7e30d1e855e0a0, 0},
}
func TestPolAdd(t *testing.T) {
for _, test := range polAddTests {
equals(t, test.sum, test.x.Add(test.y))
equals(t, test.sum, test.y.Add(test.x))
}
}
func parseBin(s string) chunker.Pol {
i, err := strconv.ParseUint(s, 2, 64)
if err != nil {
panic(err)
}
return chunker.Pol(i)
}
var polMulTests = []struct {
x, y chunker.Pol
res chunker.Pol
}{
{1, 2, 2},
{
parseBin("1101"),
parseBin("10"),
parseBin("11010"),
},
{
parseBin("1101"),
parseBin("11"),
parseBin("10111"),
},
{
0x40000000,
0x40000000,
0x1000000000000000,
},
{
parseBin("1010"),
parseBin("100100"),
parseBin("101101000"),
},
{
parseBin("100"),
parseBin("11"),
parseBin("1100"),
},
{
parseBin("11"),
parseBin("110101"),
parseBin("1011111"),
},
{
parseBin("10011"),
parseBin("110101"),
parseBin("1100001111"),
},
}
func TestPolMul(t *testing.T) {
for i, test := range polMulTests {
m := test.x.Mul(test.y)
assert(t, test.res == m,
"TestPolMul failed for test %d: %v * %v: want %v, got %v",
i, test.x, test.y, test.res, m)
m = test.y.Mul(test.x)
assert(t, test.res == test.y.Mul(test.x),
"TestPolMul failed for %d: %v * %v: want %v, got %v",
i, test.x, test.y, test.res, m)
}
}
func TestPolMulOverflow(t *testing.T) {
defer func() {
// try to recover overflow error
err := recover()
if e, ok := err.(string); ok && e == "multiplication would overflow uint64" {
return
} else {
t.Logf("invalid error raised: %v", err)
// re-raise error if not overflow
panic(err)
}
}()
x := chunker.Pol(1 << 63)
x.Mul(2)
t.Fatal("overflow test did not panic")
}
var polDivTests = []struct {
x, y chunker.Pol
res chunker.Pol
}{
{10, 50, 0},
{0, 1, 0},
{
parseBin("101101000"), // 0x168
parseBin("1010"), // 0xa
parseBin("100100"), // 0x24
},
{2, 2, 1},
{
0x8000000000000000,
0x8000000000000000,
1,
},
{
parseBin("1100"),
parseBin("100"),
parseBin("11"),
},
{
parseBin("1100001111"),
parseBin("10011"),
parseBin("110101"),
},
}
func TestPolDiv(t *testing.T) {
for i, test := range polDivTests {
m := test.x.Div(test.y)
assert(t, test.res == m,
"TestPolDiv failed for test %d: %v * %v: want %v, got %v",
i, test.x, test.y, test.res, m)
}
}
var polModTests = []struct {
x, y chunker.Pol
res chunker.Pol
}{
{10, 50, 10},
{0, 1, 0},
{
parseBin("101101001"),
parseBin("1010"),
parseBin("1"),
},
{2, 2, 0},
{
0x8000000000000000,
0x8000000000000000,
0,
},
{
parseBin("1100"),
parseBin("100"),
parseBin("0"),
},
{
parseBin("1100001111"),
parseBin("10011"),
parseBin("0"),
},
}
func TestPolModt(t *testing.T) {
for _, test := range polModTests {
equals(t, test.res, test.x.Mod(test.y))
}
}
func BenchmarkPolDivMod(t *testing.B) {
f := chunker.Pol(0x2482734cacca49)
g := chunker.Pol(0x3af4b284899)
for i := 0; i < t.N; i++ {
g.DivMod(f)
}
}
func BenchmarkPolDeg(t *testing.B) {
f := chunker.Pol(0x3af4b284899)
d := f.Deg()
if d != 41 {
t.Fatalf("BenchmalPolDeg: Wrong degree %d returned, expected %d",
d, 41)
}
for i := 0; i < t.N; i++ {
f.Deg()
}
}
func TestRandomPolynomial(t *testing.T) {
_, err := chunker.RandomPolynomial()
ok(t, err)
}
func BenchmarkRandomPolynomial(t *testing.B) {
for i := 0; i < t.N; i++ {
_, err := chunker.RandomPolynomial()
ok(t, err)
}
}
func TestExpandPolynomial(t *testing.T) {
pol := chunker.Pol(0x3DA3358B4DC173)
s := pol.Expand()
equals(t, "x^53+x^52+x^51+x^50+x^48+x^47+x^45+x^41+x^40+x^37+x^36+x^34+x^32+x^31+x^27+x^25+x^24+x^22+x^19+x^18+x^16+x^15+x^14+x^8+x^6+x^5+x^4+x+1", s)
}
var polIrredTests = []struct {
f chunker.Pol
irred bool
}{
{0x38f1e565e288df, false},
{0x3DA3358B4DC173, true},
{0x30a8295b9d5c91, false},
{0x255f4350b962cb, false},
{0x267f776110a235, false},
{0x2f4dae10d41227, false},
{0x2482734cacca49, true},
{0x312daf4b284899, false},
{0x29dfb6553d01d1, false},
{0x3548245eb26257, false},
{0x3199e7ef4211b3, false},
{0x362f39017dae8b, false},
{0x200d57aa6fdacb, false},
{0x35e0a4efa1d275, false},
{0x2ced55b026577f, false},
{0x260b012010893d, false},
{0x2df29cbcd59e9d, false},
{0x3f2ac7488bd429, false},
{0x3e5cb1711669fb, false},
{0x226d8de57a9959, false},
{0x3c8de80aaf5835, false},
{0x2026a59efb219b, false},
{0x39dfa4d13fb231, false},
{0x3143d0464b3299, false},
}
func TestPolIrreducible(t *testing.T) {
for _, test := range polIrredTests {
assert(t, test.f.Irreducible() == test.irred,
"Irreducibility test for Polynomial %v failed: got %v, wanted %v",
test.f, test.f.Irreducible(), test.irred)
}
}
var polGCDTests = []struct {
f1 chunker.Pol
f2 chunker.Pol
gcd chunker.Pol
}{
{10, 50, 2},
{0, 1, 1},
{
parseBin("101101001"),
parseBin("1010"),
parseBin("1"),
},
{2, 2, 2},
{
parseBin("1010"),
parseBin("11"),
parseBin("11"),
},
{
0x8000000000000000,
0x8000000000000000,
0x8000000000000000,
},
{
parseBin("1100"),
parseBin("101"),
parseBin("11"),
},
{
parseBin("1100001111"),
parseBin("10011"),
parseBin("10011"),
},
{
0x3DA3358B4DC173,
0x3DA3358B4DC173,
0x3DA3358B4DC173,
},
{
0x3DA3358B4DC173,
0x230d2259defd,
1,
},
{
0x230d2259defd,
0x51b492b3eff2,
parseBin("10011"),
},
}
func TestPolGCD(t *testing.T) {
for i, test := range polGCDTests {
gcd := test.f1.GCD(test.f2)
assert(t, test.gcd == gcd,
"GCD test %d (%+v) failed: got %v, wanted %v",
i, test, gcd, test.gcd)
gcd = test.f2.GCD(test.f1)
assert(t, test.gcd == gcd,
"GCD test %d (%+v) failed: got %v, wanted %v",
i, test, gcd, test.gcd)
}
}
var polMulModTests = []struct {
f1 chunker.Pol
f2 chunker.Pol
g chunker.Pol
mod chunker.Pol
}{
{
0x1230,
0x230,
0x55,
0x22,
},
{
0x0eae8c07dbbb3026,
0xd5d6db9de04771de,
0xdd2bda3b77c9,
0x425ae8595b7a,
},
}
func TestPolMulMod(t *testing.T) {
for i, test := range polMulModTests {
mod := test.f1.MulMod(test.f2, test.g)
assert(t, mod == test.mod,
"MulMod test %d (%+v) failed: got %v, wanted %v",
i, test, mod, test.mod)
}
}