Merge branch 'master' of github.com:gavofyork/ethcore-util into network

This commit is contained in:
arkpar 2016-01-15 12:18:57 +01:00
commit 223e946268
8 changed files with 303 additions and 29 deletions

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@ -15,7 +15,7 @@ mio = "0.5.0"
rand = "0.3.12" rand = "0.3.12"
time = "0.1.34" time = "0.1.34"
tiny-keccak = "1.0" tiny-keccak = "1.0"
rocksdb = "0.2" rocksdb = "0.3"
lazy_static = "0.1" lazy_static = "0.1"
eth-secp256k1 = { git = "https://github.com/arkpar/rust-secp256k1.git" } eth-secp256k1 = { git = "https://github.com/arkpar/rust-secp256k1.git" }
rust-crypto = "0.2.34" rust-crypto = "0.2.34"

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@ -195,7 +195,6 @@ macro_rules! impl_hash {
fn from_json(json: &Json) -> Self { fn from_json(json: &Json) -> Self {
match json { match json {
&Json::String(ref s) => { &Json::String(ref s) => {
println!("s: {}", s);
match s.len() % 2 { match s.len() % 2 {
0 => FromStr::from_str(clean_0x(s)).unwrap(), 0 => FromStr::from_str(clean_0x(s)).unwrap(),
_ => FromStr::from_str(&("0".to_string() + &(clean_0x(s).to_string()))[..]).unwrap() _ => FromStr::from_str(&("0".to_string() + &(clean_0x(s).to_string()))[..]).unwrap()

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@ -1,5 +1,6 @@
#![feature(op_assign_traits)] #![feature(op_assign_traits)]
#![feature(associated_consts)] #![feature(associated_consts)]
#![feature(wrapping)]
//! Ethcore-util library //! Ethcore-util library
//! //!
//! ### Rust version: //! ### Rust version:

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@ -2,6 +2,7 @@
use hash::*; use hash::*;
use bytes::*; use bytes::*;
use rlp::*;
use sha3::*; use sha3::*;
use hashdb::*; use hashdb::*;
use std::mem; use std::mem;
@ -53,13 +54,15 @@ use std::collections::HashMap;
/// ``` /// ```
pub struct MemoryDB { pub struct MemoryDB {
data: HashMap<H256, (Bytes, i32)>, data: HashMap<H256, (Bytes, i32)>,
static_null_rlp: (Bytes, i32),
} }
impl MemoryDB { impl MemoryDB {
/// Create a new instance of the memory DB. /// Create a new instance of the memory DB.
pub fn new() -> MemoryDB { pub fn new() -> MemoryDB {
MemoryDB { MemoryDB {
data: HashMap::new() data: HashMap::new(),
static_null_rlp: (vec![0x80u8; 1], 1),
} }
} }
@ -98,6 +101,9 @@ impl MemoryDB {
/// Even when Some is returned, the data is only guaranteed to be useful /// Even when Some is returned, the data is only guaranteed to be useful
/// when the refs > 0. /// when the refs > 0.
pub fn raw(&self, key: &H256) -> Option<&(Bytes, i32)> { pub fn raw(&self, key: &H256) -> Option<&(Bytes, i32)> {
if key == &SHA3_NULL_RLP {
return Some(&self.static_null_rlp);
}
self.data.get(key) self.data.get(key)
} }
@ -108,18 +114,23 @@ impl MemoryDB {
} }
pub fn denote(&self, key: &H256, value: Bytes) -> &(Bytes, i32) { pub fn denote(&self, key: &H256, value: Bytes) -> &(Bytes, i32) {
if self.data.get(&key) == None { if self.raw(key) == None {
unsafe { unsafe {
let p = &self.data as *const HashMap<H256, (Bytes, i32)> as *mut HashMap<H256, (Bytes, i32)>; let p = &self.data as *const HashMap<H256, (Bytes, i32)> as *mut HashMap<H256, (Bytes, i32)>;
(*p).insert(key.clone(), (value, 0)); (*p).insert(key.clone(), (value, 0));
} }
} }
self.data.get(key).unwrap() self.raw(key).unwrap()
} }
} }
static NULL_RLP_STATIC: [u8; 1] = [0x80; 1];
impl HashDB for MemoryDB { impl HashDB for MemoryDB {
fn lookup(&self, key: &H256) -> Option<&[u8]> { fn lookup(&self, key: &H256) -> Option<&[u8]> {
if key == &SHA3_NULL_RLP {
return Some(&NULL_RLP_STATIC);
}
match self.data.get(key) { match self.data.get(key) {
Some(&(ref d, rc)) if rc > 0 => Some(d), Some(&(ref d, rc)) if rc > 0 => Some(d),
_ => None _ => None
@ -127,10 +138,13 @@ impl HashDB for MemoryDB {
} }
fn keys(&self) -> HashMap<H256, i32> { fn keys(&self) -> HashMap<H256, i32> {
self.data.iter().filter_map(|(k, v)| if v.1 != 0 {Some((k.clone(), v.1))} else {None}).collect::<HashMap<H256, i32>>() self.data.iter().filter_map(|(k, v)| if v.1 != 0 {Some((k.clone(), v.1))} else {None}).collect()
} }
fn exists(&self, key: &H256) -> bool { fn exists(&self, key: &H256) -> bool {
if key == &SHA3_NULL_RLP {
return true;
}
match self.data.get(key) { match self.data.get(key) {
Some(&(_, x)) if x > 0 => true, Some(&(_, x)) if x > 0 => true,
_ => false _ => false
@ -138,6 +152,9 @@ impl HashDB for MemoryDB {
} }
fn insert(&mut self, value: &[u8]) -> H256 { fn insert(&mut self, value: &[u8]) -> H256 {
if value == &NULL_RLP {
return SHA3_NULL_RLP.clone();
}
let key = value.sha3(); let key = value.sha3();
if match self.data.get_mut(&key) { if match self.data.get_mut(&key) {
Some(&mut (ref mut old_value, ref mut rc @ -0x80000000i32 ... 0)) => { Some(&mut (ref mut old_value, ref mut rc @ -0x80000000i32 ... 0)) => {
@ -154,6 +171,9 @@ impl HashDB for MemoryDB {
} }
fn emplace(&mut self, key: H256, value: Bytes) { fn emplace(&mut self, key: H256, value: Bytes) {
if value == &NULL_RLP {
return;
}
match self.data.get_mut(&key) { match self.data.get_mut(&key) {
Some(&mut (ref mut old_value, ref mut rc @ -0x80000000i32 ... 0)) => { Some(&mut (ref mut old_value, ref mut rc @ -0x80000000i32 ... 0)) => {
*old_value = value; *old_value = value;
@ -168,6 +188,9 @@ impl HashDB for MemoryDB {
} }
fn kill(&mut self, key: &H256) { fn kill(&mut self, key: &H256) {
if key == &SHA3_NULL_RLP {
return;
}
if match self.data.get_mut(key) { if match self.data.get_mut(key) {
Some(&mut (_, ref mut x)) => { *x -= 1; false } Some(&mut (_, ref mut x)) => { *x -= 1; false }
None => true None => true

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@ -10,7 +10,7 @@ use std::ops::*;
use std::sync::*; use std::sync::*;
use std::env; use std::env;
use std::collections::HashMap; use std::collections::HashMap;
use rocksdb::{DB, Writable}; use rocksdb::{DB, Writable, IteratorMode};
#[derive(Clone)] #[derive(Clone)]
/// Implementation of the HashDB trait for a disk-backed database with a memory overlay. /// Implementation of the HashDB trait for a disk-backed database with a memory overlay.
@ -138,7 +138,7 @@ impl OverlayDB {
impl HashDB for OverlayDB { impl HashDB for OverlayDB {
fn keys(&self) -> HashMap<H256, i32> { fn keys(&self) -> HashMap<H256, i32> {
let mut ret: HashMap<H256, i32> = HashMap::new(); let mut ret: HashMap<H256, i32> = HashMap::new();
for (key, _) in self.backing.iterator().from_start() { for (key, _) in self.backing.iterator(IteratorMode::Start) {
let h = H256::from_slice(key.deref()); let h = H256::from_slice(key.deref());
let r = self.payload(&h).unwrap().1; let r = self.payload(&h).unwrap().1;
ret.insert(h, r as i32); ret.insert(h, r as i32);

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@ -81,7 +81,7 @@ impl<'db> TrieDB<'db> {
let mut ret = self.db.keys(); let mut ret = self.db.keys();
for (k, v) in Self::to_map(self.keys()).into_iter() { for (k, v) in Self::to_map(self.keys()).into_iter() {
let keycount = *ret.get(&k).unwrap_or(&0); let keycount = *ret.get(&k).unwrap_or(&0);
match keycount == v as i32 { match keycount <= v as i32 {
true => ret.remove(&k), true => ret.remove(&k),
_ => ret.insert(k, keycount - v as i32), _ => ret.insert(k, keycount - v as i32),
}; };

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@ -64,16 +64,13 @@ impl<'db> TrieDBMut<'db> {
}; };
// set root rlp // set root rlp
*r.root = r.db.insert(&NULL_RLP); *r.root = SHA3_NULL_RLP.clone();
r r
} }
/// Create a new trie with the backing database `db` and `root` /// Create a new trie with the backing database `db` and `root`
/// Panics, if `root` does not exist /// Panics, if `root` does not exist
pub fn from_existing(db: &'db mut HashDB, root: &'db mut H256) -> Self { pub fn from_existing(db: &'db mut HashDB, root: &'db mut H256) -> Self {
if !db.exists(root) && root == &SHA3_NULL_RLP {
*root = db.insert(&NULL_RLP);
}
assert!(db.exists(root)); assert!(db.exists(root));
TrieDBMut { TrieDBMut {
db: db, db: db,
@ -111,7 +108,7 @@ impl<'db> TrieDBMut<'db> {
let mut ret = self.db.keys(); let mut ret = self.db.keys();
for (k, v) in Self::to_map(self.keys()).into_iter() { for (k, v) in Self::to_map(self.keys()).into_iter() {
let keycount = *ret.get(&k).unwrap_or(&0); let keycount = *ret.get(&k).unwrap_or(&0);
match keycount == v as i32 { match keycount <= v as i32 {
true => ret.remove(&k), true => ret.remove(&k),
_ => ret.insert(k, keycount - v as i32), _ => ret.insert(k, keycount - v as i32),
}; };
@ -771,8 +768,9 @@ mod tests {
assert!(memtrie.db_items_remaining().is_empty()); assert!(memtrie.db_items_remaining().is_empty());
unpopulate_trie(&mut memtrie, &x); unpopulate_trie(&mut memtrie, &x);
if *memtrie.root() != SHA3_NULL_RLP || !memtrie.db_items_remaining().is_empty() { if *memtrie.root() != SHA3_NULL_RLP || !memtrie.db_items_remaining().is_empty() {
println!("TRIE MISMATCH"); println!("- TRIE MISMATCH");
println!(""); println!("");
println!("remaining: {:?}", memtrie.db_items_remaining());
println!("{:?} vs {:?}", memtrie.root(), real); println!("{:?} vs {:?}", memtrie.root(), real);
for i in x.iter() { for i in x.iter() {
println!("{:?} -> {:?}", i.0.pretty(), i.1.pretty()); println!("{:?} -> {:?}", i.0.pretty(), i.1.pretty());
@ -811,7 +809,7 @@ mod tests {
let mut t1 = TrieDBMut::new(&mut memdb, &mut root); let mut t1 = TrieDBMut::new(&mut memdb, &mut root);
t1.insert(&[0x01, 0x23], &big_value.to_vec()); t1.insert(&[0x01, 0x23], &big_value.to_vec());
t1.insert(&[0x01, 0x34], &big_value.to_vec()); t1.insert(&[0x01, 0x34], &big_value.to_vec());
trace!("keys remaining {:?}", t1.db_items_remaining()); println!("********************** keys remaining {:?}", t1.db_items_remaining());
assert!(t1.db_items_remaining().is_empty()); assert!(t1.db_items_remaining().is_empty());
let mut memdb2 = MemoryDB::new(); let mut memdb2 = MemoryDB::new();
let mut root2 = H256::new(); let mut root2 = H256::new();

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@ -23,6 +23,7 @@
use standard::*; use standard::*;
use from_json::*; use from_json::*;
use std::num::wrapping::OverflowingOps;
macro_rules! impl_map_from { macro_rules! impl_map_from {
($thing:ident, $from:ty, $to:ty) => { ($thing:ident, $from:ty, $to:ty) => {
@ -34,6 +35,13 @@ macro_rules! impl_map_from {
} }
} }
macro_rules! panic_on_overflow {
($name:expr) => {
if $name {
panic!("arithmetic operation overflow")
}
}
}
pub trait Uint: Sized + Default + FromStr + From<u64> + FromJson + fmt::Debug + fmt::Display + PartialOrd + Ord + PartialEq + Eq + Hash { pub trait Uint: Sized + Default + FromStr + From<u64> + FromJson + fmt::Debug + fmt::Display + PartialOrd + Ord + PartialEq + Eq + Hash {
/// Size of this type. /// Size of this type.
@ -183,13 +191,43 @@ macro_rules! construct_uint {
for i in 0..$n_words { for i in 0..$n_words {
let upper = other as u64 * (arr[i] >> 32); let upper = other as u64 * (arr[i] >> 32);
let lower = other as u64 * (arr[i] & 0xFFFFFFFF); let lower = other as u64 * (arr[i] & 0xFFFFFFFF);
if i < 3 {
carry[i + 1] += upper >> 32; 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;
}
} }
ret[i] = lower + (upper << 32);
} }
$name(ret) + $name(carry) $name(ret) + $name(carry)
} }
/// Overflowing multiplication by u32
fn overflowing_mul_u32(self, other: u32) -> ($name, 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, add_overflow) = $name(ret).overflowing_add($name(carry));
(result, add_overflow || overflow)
}
} }
impl Default for $name { impl Default for $name {
@ -270,6 +308,77 @@ macro_rules! construct_uint {
} }
} }
impl OverflowingOps for $name {
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, add_overflow) = $name(ret).overflowing_add($name(carry));
(ret, add_overflow || overflow)
} else {
($name(ret), overflow)
}
}
fn overflowing_sub(self, other: $name) -> ($name, bool) {
let (res, _overflow) = (!other).overflowing_add(From::from(1u64));
let (res, _overflow) = 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, mul_overflow) = self.overflowing_mul_u32((other >> (32 * i)).low_u32());
let (new_res, add_overflow) = res.overflowing_add(v << (32 * i));
res = new_res;
overflow = overflow || mul_overflow || add_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) {
// TODO [todr] not used for now
unimplemented!();
}
fn overflowing_shr(self, _shift32: u32) -> ($name, bool) {
// TODO [todr] not used for now
unimplemented!();
}
}
impl Add<$name> for $name { impl Add<$name> for $name {
type Output = $name; type Output = $name;
@ -280,10 +389,14 @@ macro_rules! construct_uint {
let mut carry = [0u64; $n_words]; let mut carry = [0u64; $n_words];
let mut b_carry = false; let mut b_carry = false;
for i in 0..$n_words { for i in 0..$n_words {
ret[i] = me[i].wrapping_add(you[i]); if i < $n_words - 1 {
if i < $n_words - 1 && ret[i] < me[i] { ret[i] = me[i].wrapping_add(you[i]);
carry[i + 1] = 1; if ret[i] < me[i] {
b_carry = true; carry[i + 1] = 1;
b_carry = true;
}
} else {
ret[i] = me[i] + you[i];
} }
} }
if b_carry { $name(ret) + $name(carry) } else { $name(ret) } if b_carry { $name(ret) + $name(carry) } else { $name(ret) }
@ -295,7 +408,10 @@ macro_rules! construct_uint {
#[inline] #[inline]
fn sub(self, other: $name) -> $name { fn sub(self, other: $name) -> $name {
self + !other + From::from(1u64) panic_on_overflow!(self < other);
let (res, _overflow) = (!other).overflowing_add(From::from(1u64));
let (res, _overflow) = self.overflowing_add(res);
res
} }
} }
@ -337,7 +453,8 @@ macro_rules! construct_uint {
loop { loop {
if sub_copy >= shift_copy { if sub_copy >= shift_copy {
ret[shift / 64] |= 1 << (shift % 64); ret[shift / 64] |= 1 << (shift % 64);
sub_copy = sub_copy - shift_copy; let (copy, _overflow) = sub_copy.overflowing_sub(shift_copy);
sub_copy = copy
} }
shift_copy = shift_copy >> 1; shift_copy = shift_copy >> 1;
if shift == 0 { break; } if shift == 0 { break; }
@ -426,7 +543,7 @@ macro_rules! construct_uint {
let bit_shift = shift % 64; let bit_shift = shift % 64;
for i in 0..$n_words { for i in 0..$n_words {
// Shift // Shift
if bit_shift < 64 && i + word_shift < $n_words { if i + word_shift < $n_words {
ret[i + word_shift] += original[i] << bit_shift; ret[i + word_shift] += original[i] << bit_shift;
} }
// Carry // Carry
@ -602,8 +719,9 @@ pub const BAD_U256: U256 = U256([0xffffffffffffffffu64; 4]);
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use uint::{Uint, U256}; use uint::{Uint, U128, U256, U512};
use std::str::FromStr; use std::str::FromStr;
use std::num::wrapping::OverflowingOps;
#[test] #[test]
pub fn uint256_from() { pub fn uint256_from() {
@ -729,7 +847,7 @@ mod tests {
let incr = shr + U256::from(1u64); let incr = shr + U256::from(1u64);
assert_eq!(incr, U256([0x7DDE000000000001u64, 0x0001BD5B7DDFBD5B, 0, 0])); assert_eq!(incr, U256([0x7DDE000000000001u64, 0x0001BD5B7DDFBD5B, 0, 0]));
// Subtraction // Subtraction
let sub = incr - init; let (sub, _of) = incr.overflowing_sub(init);
assert_eq!(sub, U256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0])); assert_eq!(sub, U256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0]));
// Multiplication // Multiplication
let mult = sub.mul_u32(300); let mult = sub.mul_u32(300);
@ -777,10 +895,145 @@ mod tests {
} }
#[test] #[test]
pub fn uint256_mul() { pub fn uint256_mul1() {
assert_eq!(U256::from(1u64) * U256::from(10u64), U256::from(10u64)); assert_eq!(U256::from(1u64) * U256::from(10u64), U256::from(10u64));
} }
#[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]
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();
}
#[ignore]
#[test]
pub fn uint256_shl_overflow() {
assert_eq!(
U256::from_str("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(4),
(U256::from_str("fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0").unwrap(), true)
);
}
#[ignore]
#[test]
#[should_panic]
pub fn uint256_shl_overflow2() {
assert_eq!(
U256::from_str("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shl(4),
(U256::from_str("fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0").unwrap(), false)
);
}
#[ignore]
#[test]
pub fn uint256_shr_overflow() {
assert_eq!(
U256::from_str("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()
.overflowing_shr(4),
(U256::from_str("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap(), true)
);
}
#[ignore]
#[test]
pub fn uint256_shr_overflow2() {
assert_eq!(
U256::from_str("fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0").unwrap()
.overflowing_shr(4),
(U256::from_str("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").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] #[test]
fn uint256_div() { fn uint256_div() {
assert_eq!(U256::from(10u64) / U256::from(1u64), U256::from(10u64)); assert_eq!(U256::from(10u64) / U256::from(1u64), U256::from(10u64));