openethereum/src/hash.rs

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//! General hash types, a fixed-size raw-data type used as the output of hash functions.
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use std::str::FromStr;
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use std::fmt;
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use std::ops;
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use std::hash::{Hash, Hasher};
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use std::ops::{Index, IndexMut, Deref, DerefMut, BitOr, BitAnd};
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use rustc_serialize::hex::*;
use error::EthcoreError;
use rand::Rng;
use rand::os::OsRng;
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use bytes::BytesConvertable;
use math::log2;
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use uint::U256;
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/// Trait for a fixed-size byte array to be used as the output of hash functions.
///
/// Note: types implementing `FixedHash` must be also `BytesConvertable`.
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pub trait FixedHash: Sized + BytesConvertable {
fn new() -> Self;
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fn random() -> Self;
fn randomize(&mut self);
fn size() -> usize;
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fn mut_bytes(&mut self) -> &mut [u8];
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fn from_slice(src: &[u8]) -> Self;
fn clone_from_slice(&mut self, src: &[u8]) -> usize;
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fn shift_bloom<'a, T>(&'a mut self, b: &T) -> &'a mut Self where T: FixedHash;
fn bloom_part<T>(&self, m: usize) -> T where T: FixedHash;
fn contains_bloom<T>(&self, b: &T) -> bool where T: FixedHash;
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fn contains<'a>(&'a self, b: &'a Self) -> bool;
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}
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macro_rules! impl_hash {
($from: ident, $size: expr) => {
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#[derive(Eq)]
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pub struct $from (pub [u8; $size]);
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impl BytesConvertable for $from {
fn bytes(&self) -> &[u8] {
&self.0
}
}
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impl Deref for $from {
type Target = [u8];
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#[inline]
fn deref(&self) -> &[u8] {
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&self.0
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}
}
impl DerefMut for $from {
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#[inline]
fn deref_mut(&mut self) -> &mut [u8] {
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&mut self.0
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}
}
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impl FixedHash for $from {
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fn new() -> $from {
$from([0; $size])
}
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fn random() -> $from {
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let mut hash = $from::new();
hash.randomize();
hash
}
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fn randomize(&mut self) {
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let mut rng = OsRng::new().unwrap();
rng.fill_bytes(&mut self.0);
}
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fn size() -> usize {
$size
}
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fn mut_bytes(&mut self) -> &mut [u8] {
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&mut self.0
}
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// TODO: remove once slice::clone_from_slice is stable
#[inline]
fn clone_from_slice(&mut self, src: &[u8]) -> usize {
let min = ::std::cmp::min($size, src.len());
let dst = &mut self.deref_mut()[.. min];
let src = &src[.. min];
for i in 0..min {
dst[i] = src[i];
}
min
}
fn from_slice(src: &[u8]) -> Self {
let mut r = Self::new();
r.clone_from_slice(src);
r
}
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fn shift_bloom<'a, T>(&'a mut self, b: &T) -> &'a mut Self where T: FixedHash {
let bp: Self = b.bloom_part($size);
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let new_self = &bp | self;
// impl |= instead
unsafe {
use std::{mem, ptr};
ptr::copy(new_self.0.as_ptr(), self.0.as_mut_ptr(), mem::size_of::<Self>());
}
self
}
fn bloom_part<T>(&self, m: usize) -> T where T: FixedHash {
// numbers of bits
// TODO: move it to some constant
let p = 3;
let bloom_bits = m * 8;
let mask = bloom_bits - 1;
let bloom_bytes = (log2(bloom_bits) + 7) / 8;
//println!("bb: {}", bloom_bytes);
// must be a power of 2
assert_eq!(m & (m - 1), 0);
// out of range
assert!(p * bloom_bytes <= $size);
// return type
let mut ret = T::new();
// 'ptr' to out slice
let mut ptr = 0;
// set p number of bits,
// p is equal 3 according to yellowpaper
for _ in 0..p {
let mut index = 0 as usize;
for _ in 0..bloom_bytes {
index = (index << 8) | self.0[ptr] as usize;
ptr += 1;
}
index &= mask;
ret.mut_bytes()[m - 1 - index / 8] |= 1 << (index % 8);
}
ret
}
fn contains_bloom<T>(&self, b: &T) -> bool where T: FixedHash {
let bp: Self = b.bloom_part($size);
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self.contains(&bp)
}
fn contains<'a>(&'a self, b: &'a Self) -> bool {
&(b & self) == b
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}
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}
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impl FromStr for $from {
type Err = EthcoreError;
fn from_str(s: &str) -> Result<$from, EthcoreError> {
let a = try!(s.from_hex());
if a.len() != $size { return Err(EthcoreError::BadSize); }
let mut ret = $from([0;$size]);
for i in 0..$size {
ret.0[i] = a[i];
}
Ok(ret)
}
}
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impl fmt::Debug for $from {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for i in self.0.iter() {
try!(write!(f, "{:02x}", i));
}
Ok(())
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}
}
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impl fmt::Display for $from {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
(self as &fmt::Debug).fmt(f)
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}
}
impl Clone for $from {
fn clone(&self) -> $from {
unsafe {
use std::{mem, ptr};
let mut ret: $from = mem::uninitialized();
ptr::copy(self.0.as_ptr(), ret.0.as_mut_ptr(), mem::size_of::<$from>());
ret
}
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}
}
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impl PartialEq for $from {
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fn eq(&self, other: &Self) -> bool {
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for i in 0..$size {
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if self.0[i] != other.0[i] {
return false;
}
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}
true
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}
}
impl Hash for $from {
fn hash<H>(&self, state: &mut H) where H: Hasher {
state.write(&self.0);
state.finish();
}
}
impl Index<usize> for $from {
type Output = u8;
fn index<'a>(&'a self, index: usize) -> &'a u8 {
&self.0[index]
}
}
impl IndexMut<usize> for $from {
fn index_mut<'a>(&'a mut self, index: usize) -> &'a mut u8 {
&mut self.0[index]
}
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}
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impl Index<ops::Range<usize>> for $from {
type Output = [u8];
fn index<'a>(&'a self, index: ops::Range<usize>) -> &'a [u8] {
&self.0[index]
}
}
impl IndexMut<ops::Range<usize>> for $from {
fn index_mut<'a>(&'a mut self, index: ops::Range<usize>) -> &'a mut [u8] {
&mut self.0[index]
}
}
impl Index<ops::RangeFull> for $from {
type Output = [u8];
fn index<'a>(&'a self, _index: ops::RangeFull) -> &'a [u8] {
&self.0
}
}
impl IndexMut<ops::RangeFull> for $from {
fn index_mut<'a>(&'a mut self, _index: ops::RangeFull) -> &'a mut [u8] {
&mut self.0
}
}
/// BitOr on references
impl<'a> BitOr for &'a $from {
type Output = $from;
fn bitor(self, rhs: Self) -> Self::Output {
unsafe {
use std::mem;
let mut ret: $from = mem::uninitialized();
for i in 0..$size {
ret.0[i] = self.0[i] | rhs.0[i];
}
ret
}
}
}
/// Moving BitOr
impl BitOr for $from {
type Output = $from;
fn bitor(self, rhs: Self) -> Self::Output {
&self | &rhs
}
}
/// BitAnd on references
impl <'a> BitAnd for &'a $from {
type Output = $from;
fn bitand(self, rhs: Self) -> Self::Output {
unsafe {
use std::mem;
let mut ret: $from = mem::uninitialized();
for i in 0..$size {
ret.0[i] = self.0[i] & rhs.0[i];
}
ret
}
}
}
/// Moving BitAnd
impl BitAnd for $from {
type Output = $from;
fn bitand(self, rhs: Self) -> Self::Output {
&self & &rhs
}
}
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impl $from {
pub fn hex(&self) -> String {
format!("{}", self)
}
}
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}
}
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impl<'a> From<&'a U256> for H256 {
fn from(value: &'a U256) -> H256 {
unsafe {
let mut ret: H256 = ::std::mem::uninitialized();
value.to_bytes(&mut ret);
ret
}
}
}
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impl_hash!(H32, 4);
impl_hash!(H64, 8);
impl_hash!(H128, 16);
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impl_hash!(Address, 20);
impl_hash!(H256, 32);
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impl_hash!(H264, 33);
impl_hash!(H512, 64);
impl_hash!(H520, 65);
impl_hash!(H1024, 128);
impl_hash!(H2048, 256);
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#[cfg(test)]
mod tests {
use hash::*;
use std::str::FromStr;
#[test]
fn hash() {
let h = H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef]);
assert_eq!(H64::from_str("0123456789abcdef").unwrap(), h);
assert_eq!(format!("{}", h), "0123456789abcdef");
assert_eq!(format!("{:?}", h), "0123456789abcdef");
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assert_eq!(h.hex(), "0123456789abcdef");
assert!(h == h);
assert!(h != H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xee]));
assert!(h != H64([0; 8]));
}
#[test]
fn hash_bitor() {
let a = H64([1; 8]);
let b = H64([2; 8]);
let c = H64([3; 8]);
// borrow
assert_eq!(&a | &b, c);
// move
assert_eq!(a | b, c);
}
#[test]
fn shift_bloom() {
use sha3::Hashable;
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let bloom = H2048::from_str("00000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002020000000000000000000000000000000000000000000008000000001000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
let address = Address::from_str("ef2d6d194084c2de36e0dabfce45d046b37d1106").unwrap();
let topic = H256::from_str("02c69be41d0b7e40352fc85be1cd65eb03d40ef8427a0ca4596b1ead9a00e9fc").unwrap();
let mut my_bloom = H2048::new();
assert!(!my_bloom.contains_bloom(&address.sha3()));
assert!(!my_bloom.contains_bloom(&topic.sha3()));
my_bloom.shift_bloom(&address.sha3());
assert!(my_bloom.contains_bloom(&address.sha3()));
assert!(!my_bloom.contains_bloom(&topic.sha3()));
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my_bloom.shift_bloom(&topic.sha3());
assert_eq!(my_bloom, bloom);
assert!(my_bloom.contains_bloom(&address.sha3()));
assert!(my_bloom.contains_bloom(&topic.sha3()));
}
}