openethereum/ethash/src/lib.rs
2018-01-10 22:19:03 +01:00

248 lines
6.8 KiB
Rust

// Copyright 2015-2017 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/>.
#![cfg_attr(feature = "benches", feature(test))]
extern crate primal;
extern crate parking_lot;
extern crate either;
extern crate memmap;
#[macro_use]
extern crate crunchy;
#[macro_use]
extern crate log;
mod compute;
mod seed_compute;
mod cache;
mod keccak;
mod shared;
pub use cache::{NodeCacheBuilder, OptimizeFor};
pub use compute::{ProofOfWork, quick_get_difficulty, slow_hash_block_number};
use compute::Light;
use keccak::H256;
use parking_lot::Mutex;
pub use seed_compute::SeedHashCompute;
pub use shared::ETHASH_EPOCH_LENGTH;
use std::mem;
use std::path::{Path, PathBuf};
use std::sync::Arc;
struct LightCache {
recent_epoch: Option<u64>,
recent: Option<Arc<Light>>,
prev_epoch: Option<u64>,
prev: Option<Arc<Light>>,
}
/// Light/Full cache manager.
pub struct EthashManager {
nodecache_builder: NodeCacheBuilder,
cache: Mutex<LightCache>,
cache_dir: PathBuf,
}
impl EthashManager {
/// Create a new new instance of ethash manager
pub fn new<T: Into<Option<OptimizeFor>>>(cache_dir: &Path, optimize_for: T) -> EthashManager {
EthashManager {
cache_dir: cache_dir.to_path_buf(),
nodecache_builder: NodeCacheBuilder::new(optimize_for.into().unwrap_or_default()),
cache: Mutex::new(LightCache {
recent_epoch: None,
recent: None,
prev_epoch: None,
prev: None,
}),
}
}
/// Calculate the light client data
/// `block_number` - Block number to check
/// `light` - The light client handler
/// `header_hash` - The header hash to pack into the mix
/// `nonce` - The nonce to pack into the mix
pub fn compute_light(&self, block_number: u64, header_hash: &H256, nonce: u64) -> ProofOfWork {
let epoch = block_number / ETHASH_EPOCH_LENGTH;
let light = {
let mut lights = self.cache.lock();
let light = match lights.recent_epoch.clone() {
Some(ref e) if *e == epoch => lights.recent.clone(),
_ => match lights.prev_epoch.clone() {
Some(e) if e == epoch => {
// don't swap if recent is newer.
if lights.recent_epoch > lights.prev_epoch {
None
} else {
// swap
let t = lights.prev_epoch;
lights.prev_epoch = lights.recent_epoch;
lights.recent_epoch = t;
let t = lights.prev.clone();
lights.prev = lights.recent.clone();
lights.recent = t;
lights.recent.clone()
}
}
_ => None,
},
};
match light {
None => {
let light = match self.nodecache_builder.light_from_file(
&self.cache_dir,
block_number,
) {
Ok(light) => Arc::new(light),
Err(e) => {
debug!("Light cache file not found for {}:{}", block_number, e);
let mut light = self.nodecache_builder.light(
&self.cache_dir,
block_number,
);
if let Err(e) = light.to_file() {
warn!("Light cache file write error: {}", e);
}
Arc::new(light)
}
};
lights.prev_epoch = mem::replace(&mut lights.recent_epoch, Some(epoch));
lights.prev = mem::replace(&mut lights.recent, Some(light.clone()));
light
}
Some(light) => light,
}
};
light.compute(header_hash, nonce)
}
}
#[test]
fn test_lru() {
let ethash = EthashManager::new(&::std::env::temp_dir(), None);
let hash = [0u8; 32];
ethash.compute_light(1, &hash, 1);
ethash.compute_light(50000, &hash, 1);
assert_eq!(ethash.cache.lock().recent_epoch.unwrap(), 1);
assert_eq!(ethash.cache.lock().prev_epoch.unwrap(), 0);
ethash.compute_light(1, &hash, 1);
assert_eq!(ethash.cache.lock().recent_epoch.unwrap(), 0);
assert_eq!(ethash.cache.lock().prev_epoch.unwrap(), 1);
ethash.compute_light(70000, &hash, 1);
assert_eq!(ethash.cache.lock().recent_epoch.unwrap(), 2);
assert_eq!(ethash.cache.lock().prev_epoch.unwrap(), 0);
}
#[cfg(feature = "benches")]
mod benchmarks {
extern crate test;
use self::test::Bencher;
use cache::{NodeCacheBuilder, OptimizeFor};
use compute::{Light, light_compute};
const HASH: [u8; 32] = [0xf5, 0x7e, 0x6f, 0x3a, 0xcf, 0xc0, 0xdd, 0x4b, 0x5b, 0xf2, 0xbe,
0xe4, 0x0a, 0xb3, 0x35, 0x8a, 0xa6, 0x87, 0x73, 0xa8, 0xd0, 0x9f,
0x5e, 0x59, 0x5e, 0xab, 0x55, 0x94, 0x05, 0x52, 0x7d, 0x72];
const NONCE: u64 = 0xd7b3ac70a301a249;
#[bench]
fn bench_light_compute_memmap(b: &mut Bencher) {
use std::env;
let builder = NodeCacheBuilder::new(OptimizeFor::Memory);
let light = builder.light(&env::temp_dir(), 486382);
b.iter(|| light_compute(&light, &HASH, NONCE));
}
#[bench]
fn bench_light_compute_memory(b: &mut Bencher) {
use std::env;
let builder = NodeCacheBuilder::new(OptimizeFor::Cpu);
let light = builder.light(&env::temp_dir(), 486382);
b.iter(|| light_compute(&light, &HASH, NONCE));
}
#[bench]
#[ignore]
fn bench_light_new_round_trip_memmap(b: &mut Bencher) {
use std::env;
b.iter(|| {
let builder = NodeCacheBuilder::new(OptimizeFor::Memory);
let light = builder.light(&env::temp_dir(), 486382);
light_compute(&light, &HASH, NONCE);
});
}
#[bench]
#[ignore]
fn bench_light_new_round_trip_memory(b: &mut Bencher) {
use std::env;
b.iter(|| {
let builder = NodeCacheBuilder::new(OptimizeFor::Cpu);
let light = builder.light(&env::temp_dir(), 486382);
light_compute(&light, &HASH, NONCE);
});
}
#[bench]
fn bench_light_from_file_round_trip_memory(b: &mut Bencher) {
use std::env;
let dir = env::temp_dir();
let height = 486382;
{
let builder = NodeCacheBuilder::new(OptimizeFor::Cpu);
let mut dummy = builder.light(&dir, height);
dummy.to_file().unwrap();
}
b.iter(|| {
let builder = NodeCacheBuilder::new(OptimizeFor::Cpu);
let light = builder.light_from_file(&dir, 486382).unwrap();
light_compute(&light, &HASH, NONCE);
});
}
#[bench]
fn bench_light_from_file_round_trip_memmap(b: &mut Bencher) {
use std::env;
let dir = env::temp_dir();
let height = 486382;
{
let builder = NodeCacheBuilder::new(OptimizeFor::Memory);
let mut dummy = builder.light(&dir, height);
dummy.to_file().unwrap();
}
b.iter(|| {
let builder = NodeCacheBuilder::new(OptimizeFor::Memory);
let light = builder.light_from_file(&dir, 486382).unwrap();
light_compute(&light, &HASH, NONCE);
});
}
}