98b7c07171
* Update `add_license` script * run script * add `remove duplicate lines script` and run it * Revert changes `English spaces` * strip whitespaces * Revert `GPL` in files with `apache/mit license` * don't append `gpl license` in files with other lic * Don't append `gpl header` in files with other lic. * re-ran script * include c and cpp files too * remove duplicate header * rebase nit
76 lines
2.1 KiB
Rust
76 lines
2.1 KiB
Rust
// Copyright 2015-2018 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/>.
|
|
|
|
#[macro_use]
|
|
extern crate crunchy;
|
|
extern crate ethereum_types;
|
|
|
|
use ethereum_types::H256;
|
|
use std::collections::{HashMap, HashSet};
|
|
use std::hash;
|
|
|
|
/// Specialized version of `HashMap` with H256 keys and fast hashing function.
|
|
pub type H256FastMap<T> = HashMap<H256, T, hash::BuildHasherDefault<PlainHasher>>;
|
|
/// Specialized version of `HashSet` with H256 keys and fast hashing function.
|
|
pub type H256FastSet = HashSet<H256, hash::BuildHasherDefault<PlainHasher>>;
|
|
|
|
/// Hasher that just takes 8 bytes of the provided value.
|
|
/// May only be used for keys which are 32 bytes.
|
|
#[derive(Default)]
|
|
pub struct PlainHasher {
|
|
prefix: u64,
|
|
}
|
|
|
|
impl hash::Hasher for PlainHasher {
|
|
#[inline]
|
|
fn finish(&self) -> u64 {
|
|
self.prefix
|
|
}
|
|
|
|
#[inline]
|
|
#[allow(unused_assignments)]
|
|
fn write(&mut self, bytes: &[u8]) {
|
|
debug_assert!(bytes.len() == 32);
|
|
let mut bytes_ptr = bytes.as_ptr();
|
|
let mut prefix_ptr = &mut self.prefix as *mut u64 as *mut u8;
|
|
|
|
unroll! {
|
|
for _i in 0..8 {
|
|
unsafe {
|
|
*prefix_ptr ^= (*bytes_ptr ^ *bytes_ptr.offset(8)) ^ (*bytes_ptr.offset(16) ^ *bytes_ptr.offset(24));
|
|
bytes_ptr = bytes_ptr.offset(1);
|
|
prefix_ptr = prefix_ptr.offset(1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use std::hash::Hasher;
|
|
use super::PlainHasher;
|
|
|
|
#[test]
|
|
fn it_works() {
|
|
let mut bytes = [32u8; 32];
|
|
bytes[0] = 15;
|
|
let mut hasher = PlainHasher::default();
|
|
hasher.write(&bytes);
|
|
assert_eq!(hasher.prefix, 47);
|
|
}
|
|
}
|