Golang Int.SetUint64方法代碼示例

func BenchmarkPe1bloop(b *testing.B) {
	bi := new(big.Int)
	bi.SetUint64(uint64(1000000))
	for i := 0; i < b.N; i++ {
		pe.Pe1bloop(bi)
	}
}

func TestDecodeBigNumber(t *testing.T) {
	var value big.Int

	value.SetUint64(^uint64(0))

	value.Mul(&value, big.NewInt(32))

	b := bytes.Buffer{}
	e := NewEncoder(&b)

	err := e.Encode(value)
	if err != nil {
		t.Fatal(err)
	}

	t.Log(hex.Dump(b.Bytes()))

	d := NewDecoder(&b)

	found, err := d.DecodeNext()
	if err != nil {
		t.Fatal(err)
	}
	i := found.(big.Int)

	if i.Cmp(&value) != 0 {
		t.Fatalf("expected %v but %v found", value, found)
	}
}

func calcDifficultyFrontier(time, parentTime uint64, parentNumber, parentDiff *big.Int) *big.Int {
	diff := new(big.Int)
	adjust := new(big.Int).Div(parentDiff, params.DifficultyBoundDivisor)
	bigTime := new(big.Int)
	bigParentTime := new(big.Int)

	bigTime.SetUint64(time)
	bigParentTime.SetUint64(parentTime)

	if bigTime.Sub(bigTime, bigParentTime).Cmp(params.DurationLimit) < 0 {
		diff.Add(parentDiff, adjust)
	} else {
		diff.Sub(parentDiff, adjust)
	}
	if diff.Cmp(params.MinimumDifficulty) < 0 {
		diff.Set(params.MinimumDifficulty)
	}

	periodCount := new(big.Int).Add(parentNumber, common.Big1)
	periodCount.Div(periodCount, ExpDiffPeriod)
	if periodCount.Cmp(common.Big1) > 0 {
		// diff = diff + 2^(periodCount - 2)
		expDiff := periodCount.Sub(periodCount, common.Big2)
		expDiff.Exp(common.Big2, expDiff, nil)
		diff.Add(diff, expDiff)
		diff = common.BigMax(diff, params.MinimumDifficulty)
	}

	return diff
}

// "stolen" from https://golang.org/pkg/math/big/#Rat.SetFloat64
// Removed non-finite case because we already check for
// Inf/NaN values
func bigIntFromFloat(f float64) *big.Int {
	const expMask = 1<<11 - 1
	bits := math.Float64bits(f)
	mantissa := bits & (1<<52 - 1)
	exp := int((bits >> 52) & expMask)
	if exp == 0 { // denormal
		exp -= 1022
	} else { // normal
		mantissa |= 1 << 52
		exp -= 1023
	}

	shift := 52 - exp

	// Optimization (?): partially pre-normalise.
	for mantissa&1 == 0 && shift > 0 {
		mantissa >>= 1
		shift--
	}

	if shift < 0 {
		shift = -shift
	}

	var a big.Int
	a.SetUint64(mantissa)
	return a.Lsh(&a, uint(shift))
}

func (m *Material) Info() [][][2]string {
	var info [][][2]string

	maybe := func(name string, stat world.Stat) {
		var total, volume, tmp big.Int
		for _, c := range m.components {
			tmp.SetUint64(c.volume)
			volume.Add(&volume, &tmp)
			total.Add(&total, tmp.Mul(c.data().Stat(stat), &tmp))
		}
		if volume.Sign() == 0 {
			return
		}
		total.Div(tmp.Mul(&total, &m.quality), &volume)
		switch total.Sign() {
		case 0:
			return
		case 1:
			info = append(info, [][2]string{
				{"+" + Comma(&total), "#4f4"},
				{name, "#ccc"},
			})
		case -1:
			info = append(info, [][2]string{
				{Comma(&total), "#f44"},
				{name, "#ccc"},
			})
		}
	}

	maybe(" power", world.StatPower)
	maybe(" magic", world.StatMagic)
	maybe(" agility", world.StatAgility)
	maybe(" luck", world.StatLuck)
	maybe(" intelligence", world.StatIntelligence)
	maybe(" stamina", world.StatStamina)
	maybe(" integrity", world.StatIntegrity)

	maybe(" melee damage", world.StatMeleeDamage)
	maybe(" magic damage", world.StatMagicDamage)
	maybe(" mana", world.StatMana)
	maybe(" mana regen", world.StatManaRegen)
	maybe(" crit chance", world.StatCritChance)
	maybe(" attack speed", world.StatAttackSpeed)

	maybe(" melee armor", world.StatMeleeArmor)
	maybe(" magic armor", world.StatMagicArmor)
	maybe(" health", world.StatHealth)
	maybe(" health regen", world.StatHealthRegen)
	maybe(" resistance", world.StatResistance)
	maybe(" movement speed", world.StatMovementSpeed)

	maybe(" gathering", world.StatGathering)
	maybe(" structure health", world.StatStructureHealth)

	return info
}

func TestPe1bloop(t *testing.T) {
	bi := new(big.Int)
	bi.SetUint64(uint64(1000))

	actual := pe.Pe1bloop(bi)
	expected := new(big.Int).SetUint64(uint64(234168))

	if actual.Cmp(expected) != 0 {
		t.Errorf("got %v, want %v", actual, expected)
	}
}

// computeChildSecret helper method that derives a child secret key from the
// intermediary state.
func (k *HDKey) computeChildSecret(ilInt *big.Int) *eckey.SecretKey {
	keyInt := new(big.Int).SetBytes(k[childKeyOffset+1:])
	defer keyInt.SetUint64(0)

	ilInt.Add(ilInt, keyInt)
	ilInt.Mod(ilInt, eckey.S256.N)

	sk := new(eckey.SecretKey)
	util.PaddedCopy(sk[:], ilInt.Bytes(), eckey.SecretSize)

	return sk
}

// Child computes the descendant of an HDKey at the specified child number.
func (k *HDKey) Child(i uint32) (*HDKey, error) {
	// Verify that child derivation is possible
	isChildHardened := i >= HardenedKeyStart
	if !k.IsPrivate() && isChildHardened {
		return nil, ErrDeriveHardenedFromPublic
	}

	// Assemble seed data for HMAC
	seed := make([]byte, childKeySize+childNumberSize)
	if isChildHardened {
		copy(seed, k[childKeyOffset:]) // Copy 0x00 || 32-byte secret key
	} else {
		copy(seed, k.CompressedPublicKey()[:]) // Copy HEADER || 32-byte X-coord
	}
	// Copy child number as uint32
	binary.BigEndian.PutUint32(seed[childKeySize:], i)

	// il, ir = HMAC-512(chainCode, seed), clean up intermediary state
	il, childChainCode := util.HMAC512Split(k.chainCode(), seed)
	defer func() { util.Zero(il); util.Zero(childChainCode) }()

	// Left 32 bytes becomes intermediate secret key, defer clean up
	ilInt := new(big.Int).SetBytes(il)
	defer ilInt.SetUint64(0)

	// Check that ilInt creates valid SecretKey, clean up intermediary SecretKey
	isk, err := eckey.NewSecretKeyInt(ilInt)
	if err != nil {
		return nil, ErrUnusableSeed
	}
	defer isk.Zero()

	ver := k.version()
	parentCPK := k.CompressedPublicKey()
	fpBytes := util.Hash256d(parentCPK[:])[:fingerprintSize]
	fp := binary.BigEndian.Uint32(fpBytes)

	// If key is private, derive a child secret key
	if k.IsPrivate() {
		sk := k.computeChildSecret(ilInt)
		return newHDSecretKey(ver, k.depth()+1, fp, i, childChainCode, sk), nil
	}

	// Otherwise, derive child public key
	cpk, err := computeChildPublic(parentCPK, isk)
	if err != nil {
		return nil, err
	}

	return newHDPublicKey(ver, k.depth()+1, fp, i, childChainCode, cpk), nil
}

func TestModSqr(t *testing.T) {
	A := new(big.Int)
	B := new(big.Int)
	for _, a := range numbers {
		A.SetUint64(a)
		b := mod_sqr(a)
		B.Mul(A, A)
		B.Mod(B, P)
		expected := B.Uint64()
		if b != expected {
			t.Fatalf("%d**2: Expecting %d but got %d", a, expected, b)
		}
	}
}

func pe1b() {
	bi := new(big.Int)
	if len(os.Args) > 1 {
		if _, ok := bi.SetString(os.Args[1], 10); !ok {
			fmt.Printf("couldn't interpret line %#v\n", os.Args[1])
		}
	} else {
		bi.SetUint64(uint64(1000))
	}

	//ans := pe.Pe1bloop(bi)
	ans := pe.Pe1b(bi)
	fmt.Println("pe1: ", ans)
}

func (m *Material) stat(stat, meta *world.Stat) *big.Int {
	var total, volume, tmp big.Int
	for _, c := range m.components {
		tmp.SetUint64(c.volume)
		volume.Add(&volume, &tmp)
		total.Add(&total, tmp.Mul(c.data().Stat(*stat), &tmp))
		if meta != nil {
			total.Add(&total, tmp.Div(tmp.Mul(c.data().Stat(*meta), tmp.SetUint64(c.volume)), world.TuningMetaStatDivisor))
		}
	}
	if volume.Sign() == 0 {
		return &volume
	}
	total.Div(tmp.Mul(&total, &m.quality), &volume)
	return &total
}

func NewSecretKey(b []byte) (*SecretKey, error) {
	if len(b) != SecretSize {
		return nil, ErrInvalidSecretLength
	}

	// Copy secret bytes and clean up
	s := new(big.Int).SetBytes(b)
	defer s.SetUint64(0)

	sk, err := NewSecretKeyInt(s)
	if err != nil {
		return nil, err
	}

	return sk, nil
}

func TestModInv(t *testing.T) {
	A := new(big.Int)
	B := new(big.Int)
	for _, a := range numbers {
		if a == 0 {
			continue
		}
		A.SetUint64(a)
		b := mod_inv(a)
		B.ModInverse(A, P)
		expected := B.Uint64()
		if b != expected {
			t.Fatalf("inv(%d): Expecting %d but got %d", a, expected, b)
		}
	}
}

func TestModShift(t *testing.T) {
	A := new(big.Int)
	C := new(big.Int)
	for _, a := range numbers {
		A.SetUint64(a)
		for b := uint8(0); b < 96; b++ {
			c := mod_shift(a, b)
			C.Lsh(A, uint(b))
			C.Mod(C, P)
			expected := C.Uint64()
			if c != expected {
				t.Fatalf("%d << %d: Expecting %d but got %d", a, b, expected, c)
			}
		}
	}
}

func TestModPow(t *testing.T) {
	A := new(big.Int)
	B := new(big.Int)
	C := new(big.Int)
	for _, a := range numbers {
		A.SetUint64(a)
		for _, b := range numbers {
			B.SetUint64(b)
			c := mod_pow(a, b)
			C.Exp(A, B, P)
			expected := C.Uint64()
			if c != expected {
				t.Errorf("0x%X ** 0x%X: Expecting 0x%X but got 0x%X", a, b, expected, c)
			}
		}
	}
}