openethereum/util/src/uint.rs

1391 lines
36 KiB
Rust

// Copyright 2015, 2016 Ethcore (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity 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 General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
// Code derived from original work by Andrew Poelstra <apoelstra@wpsoftware.net>
// Rust Bitcoin Library
// Written in 2014 by
// Andrew Poelstra <apoelstra@wpsoftware.net>
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//
//! Big unsigned integer types
//!
//! Implementation of a various large-but-fixed sized unsigned integer types.
//! The functions here are designed to be fast.
//!
use standard::*;
use from_json::*;
use rustc_serialize::hex::ToHex;
use serde;
macro_rules! impl_map_from {
($thing:ident, $from:ty, $to:ty) => {
impl From<$from> for $thing {
fn from(value: $from) -> $thing {
From::from(value as $to)
}
}
}
}
macro_rules! overflowing {
($op: expr, $overflow: expr) => (
{
let (overflow_x, overflow_overflow) = $op;
$overflow |= overflow_overflow;
overflow_x
}
);
($op: expr) => (
{
let (overflow_x, _overflow_overflow) = $op;
overflow_x
}
);
}
macro_rules! panic_on_overflow {
($name: expr) => {
if $name {
panic!("arithmetic operation overflow")
}
}
}
/// Large, fixed-length unsigned integer type.
pub trait Uint: Sized + Default + FromStr + From<u64> + FromJson + fmt::Debug + fmt::Display + PartialOrd + Ord + PartialEq + Eq + Hash {
/// Size of this type.
const SIZE: usize;
/// Returns new instance equalling zero.
fn zero() -> Self;
/// Returns new instance equalling one.
fn one() -> Self;
/// Error type for converting from a decimal string.
type FromDecStrErr;
/// Convert from a decimal string.
fn from_dec_str(value: &str) -> Result<Self, Self::FromDecStrErr>;
/// Conversion to u32
fn low_u32(&self) -> u32;
/// Conversion to u64
fn low_u64(&self) -> u64;
/// Conversion to u32 with overflow checking
fn as_u32(&self) -> u32;
/// Conversion to u64 with overflow checking
fn as_u64(&self) -> u64;
/// Return the least number of bits needed to represent the number
fn bits(&self) -> usize;
/// Return if specific bit is set
fn bit(&self, index: usize) -> bool;
/// Return single byte
fn byte(&self, index: usize) -> u8;
/// Get this Uint as slice of bytes
fn to_bytes(&self, bytes: &mut[u8]);
/// Create `Uint(10**n)`
fn exp10(n: usize) -> Self;
/// Return eponentation `self**other`. Panic on overflow.
fn pow(self, other: Self) -> Self;
/// Return wrapped eponentation `self**other` and flag if there was an overflow
fn overflowing_pow(self, other: Self) -> (Self, bool);
/// Add this `Uint` to other returning result and possible overflow
fn overflowing_add(self, other: Self) -> (Self, bool);
/// Subtract another `Uint` from this returning result and possible overflow
fn overflowing_sub(self, other: Self) -> (Self, bool);
/// Multiple this `Uint` with other returning result and possible overflow
fn overflowing_mul(self, other: Self) -> (Self, bool);
/// Divide this `Uint` by other returning result and possible overflow
fn overflowing_div(self, other: Self) -> (Self, bool);
/// Returns reminder of division of this `Uint` by other and possible overflow
fn overflowing_rem(self, other: Self) -> (Self, bool);
/// Returns negation of this `Uint` and overflow (always true)
fn overflowing_neg(self) -> (Self, bool);
/// Shifts this `Uint` and returns overflow
fn overflowing_shl(self, shift: u32) -> (Self, bool);
}
macro_rules! construct_uint {
($name:ident, $n_words:expr) => (
/// Little-endian large integer type
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct $name(pub [u64; $n_words]);
impl Uint for $name {
const SIZE: usize = $n_words * 8;
type FromDecStrErr = FromHexError;
/// TODO: optimize, throw appropriate err
fn from_dec_str(value: &str) -> Result<Self, Self::FromDecStrErr> {
Ok(value.bytes()
.map(|b| b - 48)
.fold($name::from(0u64), | acc, c |
// fast multiplication by 10
// (acc << 3) + (acc << 1) => acc * 10
(acc << 3) + (acc << 1) + $name::from(c)
))
}
#[inline]
fn low_u32(&self) -> u32 {
let &$name(ref arr) = self;
arr[0] as u32
}
#[inline]
fn low_u64(&self) -> u64 {
let &$name(ref arr) = self;
arr[0]
}
/// Conversion to u32 with overflow checking
#[inline]
fn as_u32(&self) -> u32 {
let &$name(ref arr) = self;
if (arr[0] & (0xffffffffu64 << 32)) != 0 {
panic!("Integer overflow when casting U256")
}
self.as_u64() as u32
}
/// Conversion to u64 with overflow checking
#[inline]
fn as_u64(&self) -> u64 {
let &$name(ref arr) = self;
for i in 1..$n_words {
if arr[i] != 0 {
panic!("Integer overflow when casting U256")
}
}
arr[0]
}
/// Return the least number of bits needed to represent the number
#[inline]
fn bits(&self) -> usize {
let &$name(ref arr) = self;
for i in 1..$n_words {
if arr[$n_words - i] > 0 { return (0x40 * ($n_words - i + 1)) - arr[$n_words - i].leading_zeros() as usize; }
}
0x40 - arr[0].leading_zeros() as usize
}
#[inline]
fn bit(&self, index: usize) -> bool {
let &$name(ref arr) = self;
arr[index / 64] & (1 << (index % 64)) != 0
}
#[inline]
fn byte(&self, index: usize) -> u8 {
let &$name(ref arr) = self;
(arr[index / 8] >> (((index % 8)) * 8)) as u8
}
fn to_bytes(&self, bytes: &mut[u8]) {
assert!($n_words * 8 == bytes.len());
let &$name(ref arr) = self;
for i in 0..bytes.len() {
let rev = bytes.len() - 1 - i;
let pos = rev / 8;
bytes[i] = (arr[pos] >> ((rev % 8) * 8)) as u8;
}
}
#[inline]
fn exp10(n: usize) -> Self {
match n {
0 => Self::from(1u64),
_ => Self::exp10(n - 1) * Self::from(10u64)
}
}
#[inline]
fn zero() -> Self {
From::from(0u64)
}
#[inline]
fn one() -> Self {
From::from(1u64)
}
/// Fast exponentation by squaring
/// https://en.wikipedia.org/wiki/Exponentiation_by_squaring
fn pow(self, expon: Self) -> Self {
if expon == Self::zero() {
return Self::one()
}
let is_even = |x : &Self| x.low_u64() & 1 == 0;
let u_one = Self::one();
let u_two = Self::from(2);
let mut y = u_one;
let mut n = expon;
let mut x = self;
while n > u_one {
if is_even(&n) {
x = x * x;
n = n / u_two;
} else {
y = x * y;
x = x * x;
n = (n - u_one) / u_two;
}
}
x * y
}
/// Fast exponentation by squaring
/// https://en.wikipedia.org/wiki/Exponentiation_by_squaring
fn overflowing_pow(self, expon: Self) -> (Self, bool) {
if expon == Self::zero() {
return (Self::one(), false)
}
let is_even = |x : &Self| x.low_u64() & 1 == 0;
let u_one = Self::one();
let u_two = Self::from(2);
let mut y = u_one;
let mut n = expon;
let mut x = self;
let mut overflow = false;
while n > u_one {
if is_even(&n) {
x = overflowing!(x.overflowing_mul(x), overflow);
n = n / u_two;
} else {
y = overflowing!(x.overflowing_mul(y), overflow);
x = overflowing!(x.overflowing_mul(x), overflow);
n = (n - u_one) / u_two;
}
}
let res = overflowing!(x.overflowing_mul(y), overflow);
(res, overflow)
}
fn overflowing_add(self, other: $name) -> ($name, bool) {
let $name(ref me) = self;
let $name(ref you) = other;
let mut ret = [0u64; $n_words];
let mut carry = [0u64; $n_words];
let mut b_carry = false;
let mut overflow = false;
for i in 0..$n_words {
ret[i] = me[i].wrapping_add(you[i]);
if ret[i] < me[i] {
if i < $n_words - 1 {
carry[i + 1] = 1;
b_carry = true;
} else {
overflow = true;
}
}
}
if b_carry {
let ret = overflowing!($name(ret).overflowing_add($name(carry)), overflow);
(ret, overflow)
} else {
($name(ret), overflow)
}
}
fn overflowing_sub(self, other: $name) -> ($name, bool) {
let res = overflowing!((!other).overflowing_add(From::from(1u64)));
let res = overflowing!(self.overflowing_add(res));
(res, self < other)
}
fn overflowing_mul(self, other: $name) -> ($name, bool) {
let mut res = $name::from(0u64);
let mut overflow = false;
// TODO: be more efficient about this
for i in 0..(2 * $n_words) {
let v = overflowing!(self.overflowing_mul_u32((other >> (32 * i)).low_u32()), overflow);
let res2 = overflowing!(v.overflowing_shl(32 * i as u32), overflow);
res = overflowing!(res.overflowing_add(res2), overflow);
}
(res, overflow)
}
fn overflowing_div(self, other: $name) -> ($name, bool) {
(self / other, false)
}
fn overflowing_rem(self, other: $name) -> ($name, bool) {
(self % other, false)
}
fn overflowing_neg(self) -> ($name, bool) {
(!self, true)
}
fn overflowing_shl(self, shift32: u32) -> ($name, bool) {
let $name(ref original) = self;
let mut ret = [0u64; $n_words];
let shift = shift32 as usize;
let word_shift = shift / 64;
let bit_shift = shift % 64;
for i in 0..$n_words {
// Shift
if i + word_shift < $n_words {
ret[i + word_shift] += original[i] << bit_shift;
}
// Carry
if bit_shift > 0 && i + word_shift + 1 < $n_words {
ret[i + word_shift + 1] += original[i] >> (64 - bit_shift);
}
}
// Detecting overflow
let last = $n_words - word_shift - if bit_shift > 0 { 1 } else { 0 };
let overflow = if bit_shift > 0 {
(original[last] >> (64 - bit_shift)) > 0
} else if word_shift > 0 {
original[last] > 0
} else {
false
};
for i in last+1..$n_words-1 {
if original[i] > 0 {
return ($name(ret), true);
}
}
($name(ret), overflow)
}
}
impl $name {
/// Multiplication by u32
fn mul_u32(self, other: u32) -> Self {
let $name(ref arr) = self;
let mut carry = [0u64; $n_words];
let mut ret = [0u64; $n_words];
for i in 0..$n_words {
let upper = other as u64 * (arr[i] >> 32);
let lower = other as u64 * (arr[i] & 0xFFFFFFFF);
ret[i] = lower.wrapping_add(upper << 32);
if i < $n_words - 1 {
carry[i + 1] = upper >> 32;
if ret[i] < lower {
carry[i + 1] += 1;
}
}
}
$name(ret) + $name(carry)
}
/// Overflowing multiplication by u32
fn overflowing_mul_u32(self, other: u32) -> (Self, bool) {
let $name(ref arr) = self;
let mut carry = [0u64; $n_words];
let mut ret = [0u64; $n_words];
let mut overflow = false;
for i in 0..$n_words {
let upper = other as u64 * (arr[i] >> 32);
let lower = other as u64 * (arr[i] & 0xFFFFFFFF);
ret[i] = lower.wrapping_add(upper << 32);
if i < $n_words - 1 {
carry[i + 1] = upper >> 32;
if ret[i] < lower {
carry[i + 1] += 1;
}
} else if (upper >> 32) > 0 || ret[i] < lower {
overflow = true
}
}
let result = overflowing!(
$name(ret).overflowing_add($name(carry)),
overflow
);
(result, overflow)
}
}
impl Default for $name {
fn default() -> Self {
$name::zero()
}
}
impl serde::Serialize for $name {
fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
where S: serde::Serializer {
let mut hex = "0x".to_owned();
let mut bytes = [0u8; 8 * $n_words];
self.to_bytes(&mut bytes);
let len = cmp::max((self.bits() + 7) / 8, 1);
hex.push_str(bytes[bytes.len() - len..].to_hex().as_ref());
serializer.visit_str(hex.as_ref())
}
}
impl From<u64> for $name {
fn from(value: u64) -> $name {
let mut ret = [0; $n_words];
ret[0] = value;
$name(ret)
}
}
impl FromJson for $name {
fn from_json(json: &Json) -> Self {
match *json {
Json::String(ref s) => {
if s.len() >= 2 && &s[0..2] == "0x" {
FromStr::from_str(&s[2..]).unwrap_or_else(|_| Default::default())
} else {
Uint::from_dec_str(s).unwrap_or_else(|_| Default::default())
}
},
Json::U64(u) => From::from(u),
Json::I64(i) => From::from(i as u64),
_ => Uint::zero(),
}
}
}
impl_map_from!($name, u8, u64);
impl_map_from!($name, u16, u64);
impl_map_from!($name, u32, u64);
impl_map_from!($name, usize, u64);
impl From<i64> for $name {
fn from(value: i64) -> $name {
match value >= 0 {
true => From::from(value as u64),
false => { panic!("Unsigned integer can't be created from negative value"); }
}
}
}
impl_map_from!($name, i8, i64);
impl_map_from!($name, i16, i64);
impl_map_from!($name, i32, i64);
impl_map_from!($name, isize, i64);
impl<'a> From<&'a [u8]> for $name {
fn from(bytes: &[u8]) -> $name {
assert!($n_words * 8 >= bytes.len());
let mut ret = [0; $n_words];
for i in 0..bytes.len() {
let rev = bytes.len() - 1 - i;
let pos = rev / 8;
ret[pos] += (bytes[i] as u64) << ((rev % 8) * 8);
}
$name(ret)
}
}
impl FromStr for $name {
type Err = FromHexError;
fn from_str(value: &str) -> Result<$name, Self::Err> {
let bytes: Vec<u8> = match value.len() % 2 == 0 {
true => try!(value.from_hex()),
false => try!(("0".to_owned() + value).from_hex())
};
let bytes_ref: &[u8] = &bytes;
Ok(From::from(bytes_ref))
}
}
impl Add<$name> for $name {
type Output = $name;
fn add(self, other: $name) -> $name {
let $name(ref me) = self;
let $name(ref you) = other;
let mut ret = [0u64; $n_words];
let mut carry = [0u64; $n_words];
let mut b_carry = false;
for i in 0..$n_words {
if i < $n_words - 1 {
ret[i] = me[i].wrapping_add(you[i]);
if ret[i] < me[i] {
carry[i + 1] = 1;
b_carry = true;
}
} else {
ret[i] = me[i] + you[i];
}
}
if b_carry { $name(ret) + $name(carry) } else { $name(ret) }
}
}
impl Sub<$name> for $name {
type Output = $name;
#[inline]
fn sub(self, other: $name) -> $name {
panic_on_overflow!(self < other);
let res = overflowing!((!other).overflowing_add(From::from(1u64)));
overflowing!(self.overflowing_add(res))
}
}
impl Mul<$name> for $name {
type Output = $name;
fn mul(self, other: $name) -> $name {
let mut res = $name::from(0u64);
// TODO: be more efficient about this
for i in 0..(2 * $n_words) {
let v = self.mul_u32((other >> (32 * i)).low_u32());
let (r, overflow) = v.overflowing_shl(32 * i as u32);
panic_on_overflow!(overflow);
res = res + r;
}
res
}
}
impl Div<$name> for $name {
type Output = $name;
fn div(self, other: $name) -> $name {
let mut sub_copy = self;
let mut shift_copy = other;
let mut ret = [0u64; $n_words];
let my_bits = self.bits();
let your_bits = other.bits();
// Check for division by 0
assert!(your_bits != 0);
// Early return in case we are dividing by a larger number than us
if my_bits < your_bits {
return $name(ret);
}
// Bitwise long division
let mut shift = my_bits - your_bits;
shift_copy = shift_copy << shift;
loop {
if sub_copy >= shift_copy {
ret[shift / 64] |= 1 << (shift % 64);
sub_copy = overflowing!(sub_copy.overflowing_sub(shift_copy));
}
shift_copy = shift_copy >> 1;
if shift == 0 { break; }
shift -= 1;
}
$name(ret)
}
}
impl Rem<$name> for $name {
type Output = $name;
fn rem(self, other: $name) -> $name {
let times = self / other;
self - (times * other)
}
}
// TODO: optimise and traitify.
impl<'a> AddAssign<&'a $name> for $name {
fn add_assign(&mut self, other: &'a Self) {
*self = self.add(*other);
}
}
impl<'a> SubAssign<&'a $name> for $name {
fn sub_assign(&mut self, other: &'a Self) {
*self = self.sub(*other);
}
}
impl<'a> MulAssign<&'a $name> for $name {
fn mul_assign(&mut self, other: &'a Self) {
*self = self.mul(*other);
}
}
impl<'a> DivAssign<&'a $name> for $name {
fn div_assign(&mut self, other: &'a Self) {
*self = self.div(*other);
}
}
impl<'a> RemAssign<&'a $name> for $name {
fn rem_assign(&mut self, other: &'a Self) {
*self = self.rem(*other);
}
}
impl AddAssign<$name> for $name {
fn add_assign(&mut self, other: Self) {
*self = self.add(other);
}
}
impl SubAssign<$name> for $name {
fn sub_assign(&mut self, other: Self) {
*self = self.sub(other);
}
}
impl MulAssign<$name> for $name {
fn mul_assign(&mut self, other: Self) {
*self = self.mul(other);
}
}
impl DivAssign<$name> for $name {
fn div_assign(&mut self, other: Self) {
*self = self.div(other);
}
}
impl RemAssign<$name> for $name {
fn rem_assign(&mut self, other: Self) {
*self = self.rem(other);
}
}
impl BitAnd<$name> for $name {
type Output = $name;
#[inline]
fn bitand(self, other: $name) -> $name {
let $name(ref arr1) = self;
let $name(ref arr2) = other;
let mut ret = [0u64; $n_words];
for i in 0..$n_words {
ret[i] = arr1[i] & arr2[i];
}
$name(ret)
}
}
impl BitXor<$name> for $name {
type Output = $name;
#[inline]
fn bitxor(self, other: $name) -> $name {
let $name(ref arr1) = self;
let $name(ref arr2) = other;
let mut ret = [0u64; $n_words];
for i in 0..$n_words {
ret[i] = arr1[i] ^ arr2[i];
}
$name(ret)
}
}
impl BitOr<$name> for $name {
type Output = $name;
#[inline]
fn bitor(self, other: $name) -> $name {
let $name(ref arr1) = self;
let $name(ref arr2) = other;
let mut ret = [0u64; $n_words];
for i in 0..$n_words {
ret[i] = arr1[i] | arr2[i];
}
$name(ret)
}
}
impl Not for $name {
type Output = $name;
#[inline]
fn not(self) -> $name {
let $name(ref arr) = self;
let mut ret = [0u64; $n_words];
for i in 0..$n_words {
ret[i] = !arr[i];
}
$name(ret)
}
}
impl Shl<usize> for $name {
type Output = $name;
fn shl(self, shift: usize) -> $name {
let $name(ref original) = self;
let mut ret = [0u64; $n_words];
let word_shift = shift / 64;
let bit_shift = shift % 64;
for i in 0..$n_words {
// Shift
if i + word_shift < $n_words {
ret[i + word_shift] += original[i] << bit_shift;
}
// Carry
if bit_shift > 0 && i + word_shift + 1 < $n_words {
ret[i + word_shift + 1] += original[i] >> (64 - bit_shift);
}
}
$name(ret)
}
}
impl Shr<usize> for $name {
type Output = $name;
fn shr(self, shift: usize) -> $name {
let $name(ref original) = self;
let mut ret = [0u64; $n_words];
let word_shift = shift / 64;
let bit_shift = shift % 64;
for i in word_shift..$n_words {
// Shift
ret[i - word_shift] += original[i] >> bit_shift;
// Carry
if bit_shift > 0 && i < $n_words - 1 {
ret[i - word_shift] += original[i + 1] << (64 - bit_shift);
}
}
$name(ret)
}
}
impl Ord for $name {
fn cmp(&self, other: &$name) -> Ordering {
let &$name(ref me) = self;
let &$name(ref you) = other;
for i in 0..$n_words {
if me[$n_words - 1 - i] < you[$n_words - 1 - i] { return Ordering::Less; }
if me[$n_words - 1 - i] > you[$n_words - 1 - i] { return Ordering::Greater; }
}
Ordering::Equal
}
}
impl PartialOrd for $name {
fn partial_cmp(&self, other: &$name) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl fmt::Debug for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
impl fmt::Display for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if *self == $name::zero() {
return write!(f, "0");
}
let mut s = String::new();
let mut current = *self;
let ten = $name::from(10);
while current != $name::zero() {
s = format!("{}{}", (current % ten).low_u32(), s);
current = current / ten;
}
write!(f, "{}", s)
}
}
impl fmt::LowerHex for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let &$name(ref data) = self;
try!(write!(f, "0x"));
let mut latch = false;
for ch in data.iter().rev() {
for x in 0..16 {
let nibble = (ch & (15u64 << ((15 - x) * 4) as u64)) >> (((15 - x) * 4) as u64);
if !latch { latch = nibble != 0 }
if latch {
try!(write!(f, "{:x}", nibble));
}
}
}
Ok(())
}
}
impl Hash for $name {
fn hash<H>(&self, state: &mut H) where H: Hasher {
unsafe { state.write(::std::slice::from_raw_parts(self.0.as_ptr() as *mut u8, self.0.len() * 8)); }
state.finish();
}
}
);
}
construct_uint!(U512, 8);
construct_uint!(U256, 4);
construct_uint!(U128, 2);
impl From<U256> for U512 {
fn from(value: U256) -> U512 {
let U256(ref arr) = value;
let mut ret = [0; 8];
ret[0] = arr[0];
ret[1] = arr[1];
ret[2] = arr[2];
ret[3] = arr[3];
U512(ret)
}
}
impl From<U512> for U256 {
fn from(value: U512) -> U256 {
let U512(ref arr) = value;
if arr[4] | arr[5] | arr[6] | arr[7] != 0 {
panic!("Overflow");
}
let mut ret = [0; 4];
ret[0] = arr[0];
ret[1] = arr[1];
ret[2] = arr[2];
ret[3] = arr[3];
U256(ret)
}
}
impl From<U256> for U128 {
fn from(value: U256) -> U128 {
let U256(ref arr) = value;
if arr[2] | arr[3] != 0 {
panic!("Overflow");
}
let mut ret = [0; 2];
ret[0] = arr[0];
ret[1] = arr[1];
U128(ret)
}
}
impl From<U512> for U128 {
fn from(value: U512) -> U128 {
let U512(ref arr) = value;
if arr[2] | arr[3] | arr[4] | arr[5] | arr[6] | arr[7] != 0 {
panic!("Overflow");
}
let mut ret = [0; 2];
ret[0] = arr[0];
ret[1] = arr[1];
U128(ret)
}
}
impl From<U128> for U512 {
fn from(value: U128) -> U512 {
let U128(ref arr) = value;
let mut ret = [0; 8];
ret[0] = arr[0];
ret[1] = arr[1];
U512(ret)
}
}
impl From<U128> for U256 {
fn from(value: U128) -> U256 {
let U128(ref arr) = value;
let mut ret = [0; 4];
ret[0] = arr[0];
ret[1] = arr[1];
U256(ret)
}
}
impl From<U256> for u64 {
fn from(value: U256) -> u64 {
value.as_u64()
}
}
impl From<U256> for u32 {
fn from(value: U256) -> u32 {
value.as_u32()
}
}
/// Constant value of `U256::zero()` that can be used for a reference saving an additional instance creation.
pub const ZERO_U256: U256 = U256([0x00u64; 4]);
/// Constant value of `U256::one()` that can be used for a reference saving an additional instance creation.
pub const ONE_U256: U256 = U256([0x01u64, 0x00u64, 0x00u64, 0x00u64]);
#[cfg(test)]
mod tests {
use uint::{Uint, U128, U256, U512};
use std::str::FromStr;
#[test]
pub fn assign_ops() {
let x: U256 = x!(69);
let y: U256 = x!(42);
{
let mut z = x;
z += y;
assert_eq!(z, x + y);
}
{
let mut z = x;
z -= y;
assert_eq!(z, x - y);
}
{
let mut z = x;
z *= y;
assert_eq!(z, x * y);
}
{
let mut z = x;
z /= y;
assert_eq!(z, x / y);
}
{
let mut z = x;
z %= y;
assert_eq!(z, x % y);
}
}
#[test]
pub fn uint256_from() {
let e = U256([10, 0, 0, 0]);
// test unsigned initialization
let ua = U256::from(10u8);
let ub = U256::from(10u16);
let uc = U256::from(10u32);
let ud = U256::from(10u64);
assert_eq!(e, ua);
assert_eq!(e, ub);
assert_eq!(e, uc);
assert_eq!(e, ud);
// test initialization from bytes
let va = U256::from(&[10u8][..]);
assert_eq!(e, va);
// more tests for initialization from bytes
assert_eq!(U256([0x1010, 0, 0, 0]), U256::from(&[0x10u8, 0x10][..]));
assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from(&[0x12u8, 0xf0][..]));
assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from(&[0, 0x12u8, 0xf0][..]));
assert_eq!(U256([0x12f0, 0 , 0, 0]), U256::from(&[0, 0, 0, 0, 0, 0, 0, 0x12u8, 0xf0][..]));
assert_eq!(U256([0x12f0, 1 , 0, 0]), U256::from(&[1, 0, 0, 0, 0, 0, 0, 0x12u8, 0xf0][..]));
assert_eq!(U256([0x12f0, 1 , 0x0910203040506077, 0x8090a0b0c0d0e0f0]), U256::from(&[
0x80, 0x90, 0xa0, 0xb0, 0xc0, 0xd0, 0xe0, 0xf0,
0x09, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x77,
0, 0, 0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0x12u8, 0xf0][..]));
assert_eq!(U256([0x00192437100019fa, 0x243710, 0, 0]), U256::from(&[
0x24u8, 0x37, 0x10,
0, 0x19, 0x24, 0x37, 0x10, 0, 0x19, 0xfa][..]));
// test initializtion from string
let sa = U256::from_str("0a").unwrap();
assert_eq!(e, sa);
assert_eq!(U256([0x1010, 0, 0, 0]), U256::from_str("1010").unwrap());
assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from_str("12f0").unwrap());
assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from_str("12f0").unwrap());
assert_eq!(U256([0x12f0, 0 , 0, 0]), U256::from_str("0000000012f0").unwrap());
assert_eq!(U256([0x12f0, 1 , 0, 0]), U256::from_str("0100000000000012f0").unwrap());
assert_eq!(U256([0x12f0, 1 , 0x0910203040506077, 0x8090a0b0c0d0e0f0]), U256::from_str("8090a0b0c0d0e0f00910203040506077000000000000000100000000000012f0").unwrap());
}
#[test]
pub fn uint256_to() {
let hex = "8090a0b0c0d0e0f00910203040506077583a2cf8264910e1436bda32571012f0";
let uint = U256::from_str(hex).unwrap();
let mut bytes = [0u8; 32];
uint.to_bytes(&mut bytes);
let uint2 = U256::from(&bytes[..]);
assert_eq!(uint, uint2);
}
#[test]
pub fn uint256_bits_test() {
assert_eq!(U256::from(0u64).bits(), 0);
assert_eq!(U256::from(255u64).bits(), 8);
assert_eq!(U256::from(256u64).bits(), 9);
assert_eq!(U256::from(300u64).bits(), 9);
assert_eq!(U256::from(60000u64).bits(), 16);
assert_eq!(U256::from(70000u64).bits(), 17);
//// Try to read the following lines out loud quickly
let mut shl = U256::from(70000u64);
shl = shl << 100;
assert_eq!(shl.bits(), 117);
shl = shl << 100;
assert_eq!(shl.bits(), 217);
shl = shl << 100;
assert_eq!(shl.bits(), 0);
//// Bit set check
//// 01010
assert!(!U256::from(10u8).bit(0));
assert!(U256::from(10u8).bit(1));
assert!(!U256::from(10u8).bit(2));
assert!(U256::from(10u8).bit(3));
assert!(!U256::from(10u8).bit(4));
//// byte check
assert_eq!(U256::from(10u8).byte(0), 10);
assert_eq!(U256::from(0xffu64).byte(0), 0xff);
assert_eq!(U256::from(0xffu64).byte(1), 0);
assert_eq!(U256::from(0x01ffu64).byte(0), 0xff);
assert_eq!(U256::from(0x01ffu64).byte(1), 0x1);
assert_eq!(U256([0u64, 0xfc, 0, 0]).byte(8), 0xfc);
assert_eq!(U256([0u64, 0, 0, u64::max_value()]).byte(31), 0xff);
assert_eq!(U256([0u64, 0, 0, (u64::max_value() >> 8) + 1]).byte(31), 0x01);
}
#[test]
#[allow(eq_op)]
pub fn uint256_comp_test() {
let small = U256([10u64, 0, 0, 0]);
let big = U256([0x8C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0]);
let bigger = U256([0x9C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0]);
let biggest = U256([0x5C8C3EE70C644118u64, 0x0209E7378231E632, 0, 1]);
assert!(small < big);
assert!(big < bigger);
assert!(bigger < biggest);
assert!(bigger <= biggest);
assert!(biggest <= biggest);
assert!(bigger >= big);
assert!(bigger >= small);
assert!(small <= small);
}
#[test]
pub fn uint256_arithmetic_test() {
let init = U256::from(0xDEADBEEFDEADBEEFu64);
let copy = init;
let add = init + copy;
assert_eq!(add, U256([0xBD5B7DDFBD5B7DDEu64, 1, 0, 0]));
// Bitshifts
let shl = add << 88;
assert_eq!(shl, U256([0u64, 0xDFBD5B7DDE000000, 0x1BD5B7D, 0]));
let shr = shl >> 40;
assert_eq!(shr, U256([0x7DDE000000000000u64, 0x0001BD5B7DDFBD5B, 0, 0]));
// Increment
let incr = shr + U256::from(1u64);
assert_eq!(incr, U256([0x7DDE000000000001u64, 0x0001BD5B7DDFBD5B, 0, 0]));
// Subtraction
let sub = overflowing!(incr.overflowing_sub(init));
assert_eq!(sub, U256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0]));
// Multiplication
let mult = sub.mul_u32(300);
assert_eq!(mult, U256([0x8C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0]));
// Division
assert_eq!(U256::from(105u8) / U256::from(5u8), U256::from(21u8));
let div = mult / U256::from(300u16);
assert_eq!(div, U256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0]));
//// TODO: bit inversion
}
#[test]
pub fn uint256_extreme_bitshift_test() {
//// Shifting a u64 by 64 bits gives an undefined value, so make sure that
//// we're doing the Right Thing here
let init = U256::from(0xDEADBEEFDEADBEEFu64);
assert_eq!(init << 64, U256([0, 0xDEADBEEFDEADBEEF, 0, 0]));
let add = (init << 64) + init;
assert_eq!(add, U256([0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0, 0]));
assert_eq!(add >> 0, U256([0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0, 0]));
assert_eq!(add << 0, U256([0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0, 0]));
assert_eq!(add >> 64, U256([0xDEADBEEFDEADBEEF, 0, 0, 0]));
assert_eq!(add << 64, U256([0, 0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0]));
}
#[test]
pub fn uint256_exp10() {
assert_eq!(U256::exp10(0), U256::from(1u64));
println!("\none: {:?}", U256::from(1u64));
println!("ten: {:?}", U256::from(10u64));
assert_eq!(U256::from(2u64) * U256::from(10u64), U256::from(20u64));
assert_eq!(U256::exp10(1), U256::from(10u64));
assert_eq!(U256::exp10(2), U256::from(100u64));
assert_eq!(U256::exp10(5), U256::from(100000u64));
}
#[test]
pub fn uint256_mul32() {
assert_eq!(U256::from(0u64).mul_u32(2), U256::from(0u64));
assert_eq!(U256::from(1u64).mul_u32(2), U256::from(2u64));
assert_eq!(U256::from(10u64).mul_u32(2), U256::from(20u64));
assert_eq!(U256::from(10u64).mul_u32(5), U256::from(50u64));
assert_eq!(U256::from(1000u64).mul_u32(50), U256::from(50000u64));
}
#[test]
fn uint256_pow () {
assert_eq!(U256::from(10).pow(U256::from(0)), U256::from(1));
assert_eq!(U256::from(10).pow(U256::from(1)), U256::from(10));
assert_eq!(U256::from(10).pow(U256::from(2)), U256::from(100));
assert_eq!(U256::from(10).pow(U256::from(3)), U256::from(1000));
assert_eq!(U256::from(10).pow(U256::from(20)), U256::exp10(20));
}
#[test]
#[should_panic]
fn uint256_pow_overflow_panic () {
U256::from(2).pow(U256::from(0x100));
}
#[test]
fn uint256_overflowing_pow () {
// assert_eq!(
// U256::from(2).overflowing_pow(U256::from(0xff)),
// (U256::from_str("8000000000000000000000000000000000000000000000000000000000000000").unwrap(), false)
// );
assert_eq!(
U256::from(2).overflowing_pow(U256::from(0x100)),
(U256::zero(), true)
);
}
#[test]
pub fn uint256_mul1() {
assert_eq!(U256::from(1u64) * U256::from(10u64), U256::from(10u64));
}
#[test]
pub fn uint256_overflowing_mul() {
assert_eq!(
U256::from_str("100000000000000000000000000000000").unwrap().overflowing_mul(
U256::from_str("100000000000000000000000000000000").unwrap()
),
(U256::zero(), true)
);
}
#[test]
pub fn uint128_add() {
assert_eq!(
U128::from_str("fffffffffffffffff").unwrap() + U128::from_str("fffffffffffffffff").unwrap(),
U128::from_str("1ffffffffffffffffe").unwrap()
);
}
#[test]
pub fn uint128_add_overflow() {
assert_eq!(
U128::from_str("ffffffffffffffffffffffffffffffff").unwrap()
.overflowing_add(
U128::from_str("ffffffffffffffffffffffffffffffff").unwrap()
),
(U128::from_str("fffffffffffffffffffffffffffffffe").unwrap(), true)
);
}
#[test]
#[should_panic]
// overflows panic only in debug builds. Running this test with `--release` flag, always fails
#[ignore]
pub fn uint128_add_overflow_panic() {
U128::from_str("ffffffffffffffffffffffffffffffff").unwrap()
+
U128::from_str("ffffffffffffffffffffffffffffffff").unwrap();
}
#[test]
pub fn uint128_mul() {
assert_eq!(
U128::from_str("fffffffff").unwrap() * U128::from_str("fffffffff").unwrap(),
U128::from_str("ffffffffe000000001").unwrap());
}
#[test]
pub fn uint512_mul() {
assert_eq!(
U512::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
*
U512::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap(),
U512::from_str("3fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000000000000000000000000000000000000000000000000001").unwrap()
);
}
#[test]
pub fn uint256_mul_overflow() {
assert_eq!(
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_mul(
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
),
(U256::from_str("1").unwrap(), true)
);
}
#[test]
#[should_panic]
pub fn uint256_mul_overflow_panic() {
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
*
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap();
}
#[test]
pub fn uint256_sub_overflow() {
assert_eq!(
U256::from_str("0").unwrap()
.overflowing_sub(
U256::from_str("1").unwrap()
),
(U256::from_str("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap(), true)
);
}
#[test]
#[should_panic]
pub fn uint256_sub_overflow_panic() {
U256::from_str("0").unwrap()
-
U256::from_str("1").unwrap();
}
#[test]
pub fn uint256_shl_overflow() {
assert_eq!(
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(4),
(U256::from_str("fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0").unwrap(), true)
);
}
#[test]
pub fn uint256_shl_overflow_words() {
assert_eq!(
U256::from_str("0000000000000001ffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(64),
(U256::from_str("ffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000").unwrap(), true)
);
assert_eq!(
U256::from_str("0000000000000000ffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(64),
(U256::from_str("ffffffffffffffffffffffffffffffffffffffffffffffff0000000000000000").unwrap(), false)
);
}
#[test]
pub fn uint256_shl_overflow_words2() {
assert_eq!(
U256::from_str("00000000000000000000000000000001ffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(128),
(U256::from_str("ffffffffffffffffffffffffffffffff00000000000000000000000000000000").unwrap(), true)
);
assert_eq!(
U256::from_str("00000000000000000000000000000000ffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(128),
(U256::from_str("ffffffffffffffffffffffffffffffff00000000000000000000000000000000").unwrap(), false)
);
assert_eq!(
U256::from_str("00000000000000000000000000000000ffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(129),
(U256::from_str("fffffffffffffffffffffffffffffffe00000000000000000000000000000000").unwrap(), true)
);
}
#[test]
pub fn uint256_shl_overflow2() {
assert_eq!(
U256::from_str("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(4),
(U256::from_str("fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0").unwrap(), false)
);
}
#[test]
pub fn uint256_mul() {
assert_eq!(
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
*
U256::from_str("2").unwrap(),
U256::from_str("fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe").unwrap()
);
}
#[test]
fn uint256_div() {
assert_eq!(U256::from(10u64) / U256::from(1u64), U256::from(10u64));
assert_eq!(U256::from(10u64) / U256::from(2u64), U256::from(5u64));
assert_eq!(U256::from(10u64) / U256::from(3u64), U256::from(3u64));
}
#[test]
fn uint256_rem() {
assert_eq!(U256::from(10u64) % U256::from(1u64), U256::from(0u64));
assert_eq!(U256::from(10u64) % U256::from(3u64), U256::from(1u64));
}
#[test]
fn uint256_from_dec_str() {
assert_eq!(U256::from_dec_str("10").unwrap(), U256::from(10u64));
assert_eq!(U256::from_dec_str("1024").unwrap(), U256::from(1024u64));
}
#[test]
fn display_uint() {
let s = "12345678987654321023456789";
assert_eq!(format!("{}", U256::from_dec_str(s).unwrap()), s);
}
#[test]
fn display_uint_zero() {
assert_eq!(format!("{}", U256::from(0)), "0");
}
}