openethereum/util/bigint/src/hash.rs
2016-12-11 19:30:54 +01:00

585 lines
13 KiB
Rust

// Copyright 2015, 2016 Parity Technologies (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/>.
//! General hash types, a fixed-size raw-data type used as the output of hash functions.
use std::{ops, fmt, cmp};
use std::cmp::{min, Ordering};
use std::ops::{Deref, DerefMut, BitXor, BitAnd, BitOr, IndexMut, Index};
use std::hash::{Hash, Hasher, BuildHasherDefault};
use std::collections::{HashMap, HashSet};
use std::str::FromStr;
use rand::Rng;
use rand::os::OsRng;
use rustc_serialize::hex::{FromHex, FromHexError};
use uint::{Uint, U256};
/// Trait for a fixed-size byte array to be used as the output of hash functions.
pub trait FixedHash: Sized {
/// Create a new, zero-initialised, instance.
fn new() -> Self;
/// Synonym for `new()`. Prefer to new as it's more readable.
fn zero() -> Self;
/// Create a new, cryptographically random, instance.
fn random() -> Self;
/// Assign self have a cryptographically random value.
fn randomize(&mut self);
/// Get the size of this object in bytes.
fn len() -> usize;
/// Convert a slice of bytes of length `len()` to an instance of this type.
fn from_slice(src: &[u8]) -> Self;
/// Assign self to be of the same value as a slice of bytes of length `len()`.
fn clone_from_slice(&mut self, src: &[u8]) -> usize;
/// Copy the data of this object into some mutable slice of length `len()`.
fn copy_to(&self, dest: &mut [u8]);
/// Returns `true` if all bits set in `b` are also set in `self`.
fn contains<'a>(&'a self, b: &'a Self) -> bool;
/// Returns `true` if no bits are set.
fn is_zero(&self) -> bool;
/// Returns the lowest 8 bytes interpreted as a BigEndian integer.
fn low_u64(&self) -> u64;
}
/// Return `s` without the `0x` at the beginning of it, if any.
pub fn clean_0x(s: &str) -> &str {
if s.starts_with("0x") {
&s[2..]
} else {
s
}
}
macro_rules! impl_hash {
($from: ident, $size: expr) => {
#[repr(C)]
/// Unformatted binary data of fixed length.
pub struct $from (pub [u8; $size]);
impl From<[u8; $size]> for $from {
fn from(bytes: [u8; $size]) -> Self {
$from(bytes)
}
}
impl From<$from> for [u8; $size] {
fn from(s: $from) -> Self {
s.0
}
}
impl Deref for $from {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
&self.0
}
}
impl AsRef<[u8]> for $from {
#[inline]
fn as_ref(&self) -> &[u8] {
&self.0
}
}
impl DerefMut for $from {
#[inline]
fn deref_mut(&mut self) -> &mut [u8] {
&mut self.0
}
}
impl FixedHash for $from {
fn new() -> $from {
$from([0; $size])
}
fn zero() -> $from {
$from([0; $size])
}
fn random() -> $from {
let mut hash = $from::new();
hash.randomize();
hash
}
fn randomize(&mut self) {
let mut rng = OsRng::new().unwrap();
rng.fill_bytes(&mut self.0);
}
fn len() -> usize {
$size
}
#[inline]
fn clone_from_slice(&mut self, src: &[u8]) -> usize {
let min = cmp::min($size, src.len());
self.0[..min].copy_from_slice(&src[..min]);
min
}
fn from_slice(src: &[u8]) -> Self {
let mut r = Self::new();
r.clone_from_slice(src);
r
}
fn copy_to(&self, dest: &mut[u8]) {
let min = cmp::min($size, dest.len());
dest[..min].copy_from_slice(&self.0[..min]);
}
fn contains<'a>(&'a self, b: &'a Self) -> bool {
&(b & self) == b
}
fn is_zero(&self) -> bool {
self.eq(&Self::new())
}
fn low_u64(&self) -> u64 {
let mut ret = 0u64;
for i in 0..min($size, 8) {
ret |= (self.0[$size - 1 - i] as u64) << (i * 8);
}
ret
}
}
impl FromStr for $from {
type Err = FromHexError;
fn from_str(s: &str) -> Result<$from, FromHexError> {
let a = try!(s.from_hex());
if a.len() != $size {
return Err(FromHexError::InvalidHexLength);
}
let mut ret = [0;$size];
ret.copy_from_slice(&a);
Ok($from(ret))
}
}
impl fmt::Debug for $from {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for i in &self.0[..] {
try!(write!(f, "{:02x}", i));
}
Ok(())
}
}
impl fmt::Display for $from {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for i in &self.0[0..2] {
try!(write!(f, "{:02x}", i));
}
try!(write!(f, ""));
for i in &self.0[$size - 2..$size] {
try!(write!(f, "{:02x}", i));
}
Ok(())
}
}
impl Copy for $from {}
#[cfg_attr(feature="dev", allow(expl_impl_clone_on_copy))]
impl Clone for $from {
fn clone(&self) -> $from {
let mut ret = $from::new();
ret.0.copy_from_slice(&self.0);
ret
}
}
impl Eq for $from {}
impl PartialEq for $from {
fn eq(&self, other: &Self) -> bool {
for i in 0..$size {
if self.0[i] != other.0[i] {
return false;
}
}
true
}
}
impl Ord for $from {
fn cmp(&self, other: &Self) -> Ordering {
for i in 0..$size {
if self.0[i] > other.0[i] {
return Ordering::Greater;
} else if self.0[i] < other.0[i] {
return Ordering::Less;
}
}
Ordering::Equal
}
}
impl PartialOrd for $from {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
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(&self, index: usize) -> &u8 {
&self.0[index]
}
}
impl IndexMut<usize> for $from {
fn index_mut(&mut self, index: usize) -> &mut u8 {
&mut self.0[index]
}
}
impl Index<ops::Range<usize>> for $from {
type Output = [u8];
fn index(&self, index: ops::Range<usize>) -> &[u8] {
&self.0[index]
}
}
impl IndexMut<ops::Range<usize>> for $from {
fn index_mut(&mut self, index: ops::Range<usize>) -> &mut [u8] {
&mut self.0[index]
}
}
impl Index<ops::RangeFull> for $from {
type Output = [u8];
fn index(&self, _index: ops::RangeFull) -> &[u8] {
&self.0
}
}
impl IndexMut<ops::RangeFull> for $from {
fn index_mut(&mut self, _index: ops::RangeFull) -> &mut [u8] {
&mut self.0
}
}
/// `BitOr` on references
impl<'a> BitOr for &'a $from {
type Output = $from;
fn bitor(self, rhs: Self) -> Self::Output {
let mut ret: $from = $from::default();
for i in 0..$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 {
let mut ret: $from = $from::default();
for i in 0..$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
}
}
/// `BitXor` on references
impl <'a> BitXor for &'a $from {
type Output = $from;
fn bitxor(self, rhs: Self) -> Self::Output {
let mut ret: $from = $from::default();
for i in 0..$size {
ret.0[i] = self.0[i] ^ rhs.0[i];
}
ret
}
}
/// Moving `BitXor`
impl BitXor for $from {
type Output = $from;
fn bitxor(self, rhs: Self) -> Self::Output {
&self ^ &rhs
}
}
impl $from {
/// Get a hex representation.
pub fn hex(&self) -> String {
format!("{:?}", self)
}
}
impl Default for $from {
fn default() -> Self { $from::new() }
}
impl From<u64> for $from {
fn from(mut value: u64) -> $from {
let mut ret = $from::new();
for i in 0..8 {
if i < $size {
ret.0[$size - i - 1] = (value & 0xff) as u8;
value >>= 8;
}
}
ret
}
}
impl From<&'static str> for $from {
fn from(s: &'static str) -> $from {
let s = clean_0x(s);
if s.len() % 2 == 1 {
$from::from_str(&("0".to_owned() + s)).unwrap()
} else {
$from::from_str(s).unwrap()
}
}
}
impl<'a> From<&'a [u8]> for $from {
fn from(s: &'a [u8]) -> $from {
$from::from_slice(s)
}
}
}
}
impl From<U256> for H256 {
fn from(value: U256) -> H256 {
let mut ret = H256::new();
value.to_big_endian(&mut ret);
ret
}
}
impl<'a> From<&'a U256> for H256 {
fn from(value: &'a U256) -> H256 {
let mut ret: H256 = H256::new();
value.to_big_endian(&mut ret);
ret
}
}
impl From<H256> for U256 {
fn from(value: H256) -> U256 {
U256::from(&value)
}
}
impl<'a> From<&'a H256> for U256 {
fn from(value: &'a H256) -> U256 {
U256::from(value.as_ref() as &[u8])
}
}
impl From<H256> for H160 {
fn from(value: H256) -> H160 {
let mut ret = H160::new();
ret.0.copy_from_slice(&value[12..32]);
ret
}
}
impl From<H256> for H64 {
fn from(value: H256) -> H64 {
let mut ret = H64::new();
ret.0.copy_from_slice(&value[20..28]);
ret
}
}
impl From<H160> for H256 {
fn from(value: H160) -> H256 {
let mut ret = H256::new();
ret.0[12..32].copy_from_slice(&value);
ret
}
}
impl<'a> From<&'a H160> for H256 {
fn from(value: &'a H160) -> H256 {
let mut ret = H256::new();
ret.0[12..32].copy_from_slice(value);
ret
}
}
impl_hash!(H32, 4);
impl_hash!(H64, 8);
impl_hash!(H128, 16);
impl_hash!(H160, 20);
impl_hash!(H256, 32);
impl_hash!(H264, 33);
impl_hash!(H512, 64);
impl_hash!(H520, 65);
impl_hash!(H1024, 128);
impl_hash!(H2048, 256);
known_heap_size!(0, H32, H64, H128, H160, H256, H264, H512, H520, H1024, H2048);
// Specialized HashMap and HashSet
/// Hasher that just takes 8 bytes of the provided value.
/// May only be used for keys which are 32 bytes.
pub struct PlainHasher {
prefix: [u8; 8],
_marker: [u64; 0], // for alignment
}
impl Default for PlainHasher {
#[inline]
fn default() -> PlainHasher {
PlainHasher {
prefix: [0; 8],
_marker: [0; 0],
}
}
}
impl Hasher for PlainHasher {
#[inline]
fn finish(&self) -> u64 {
unsafe { ::std::mem::transmute(self.prefix) }
}
#[inline]
fn write(&mut self, bytes: &[u8]) {
debug_assert!(bytes.len() == 32);
for quarter in bytes.chunks(8) {
for (x, y) in self.prefix.iter_mut().zip(quarter) {
*x ^= *y
}
}
}
}
/// Specialized version of `HashMap` with H256 keys and fast hashing function.
pub type H256FastMap<T> = HashMap<H256, T, BuildHasherDefault<PlainHasher>>;
/// Specialized version of `HashSet` with H256 keys and fast hashing function.
pub type H256FastSet = HashSet<H256, BuildHasherDefault<PlainHasher>>;
#[cfg(test)]
mod tests {
use hash::*;
use uint::*;
use std::str::FromStr;
#[test]
fn hasher_alignment() {
use std::mem::align_of;
assert_eq!(align_of::<u64>(), align_of::<PlainHasher>());
}
#[test]
#[cfg_attr(feature="dev", allow(eq_op))]
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), "0123…cdef");
assert_eq!(format!("{:?}", h), "0123456789abcdef");
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 from_and_to_address() {
let address: H160 = "ef2d6d194084c2de36e0dabfce45d046b37d1106".into();
let h = H256::from(address.clone());
let a = H160::from(h);
assert_eq!(address, a);
}
#[test]
fn from_u64() {
assert_eq!(H128::from(0x1234567890abcdef), H128::from_str("00000000000000001234567890abcdef").unwrap());
assert_eq!(H64::from(0x1234567890abcdef), H64::from_str("1234567890abcdef").unwrap());
assert_eq!(H32::from(0x1234567890abcdef), H32::from_str("90abcdef").unwrap());
}
#[test]
fn from_str() {
assert_eq!(H64::from(0x1234567890abcdef), H64::from("0x1234567890abcdef"));
assert_eq!(H64::from(0x1234567890abcdef), H64::from("1234567890abcdef"));
assert_eq!(H64::from(0x234567890abcdef), H64::from("0x234567890abcdef"));
}
#[test]
fn from_and_to_u256() {
let u: U256 = 0x123456789abcdef0u64.into();
let h = H256::from(u);
assert_eq!(H256::from(u), H256::from("000000000000000000000000000000000000000000000000123456789abcdef0"));
let h_ref = H256::from(&u);
assert_eq!(h, h_ref);
let r_ref: U256 = From::from(&h);
assert_eq!(r_ref, u);
let r: U256 = From::from(h);
assert_eq!(r, u);
}
}