openethereum/ethash/src/lib.rs
2016-02-05 13:40:41 +01:00

76 lines
2.3 KiB
Rust

// Copyright 2015, 2016 Ethcore (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/>.
//! Ethash implementation
//! See https://github.com/ethereum/wiki/wiki/Ethash
extern crate sha3;
extern crate lru_cache;
#[macro_use]
extern crate log;
mod sizes;
mod compute;
use lru_cache::LruCache;
use compute::Light;
pub use compute::{quick_get_difficulty, H256, ProofOfWork, ETHASH_EPOCH_LENGTH};
use std::sync::{Arc, Mutex};
/// Lighy/Full cache manager
pub struct EthashManager {
lights: Mutex<LruCache<u64, Arc<Light>>>
}
impl EthashManager {
/// Create a new new instance of ethash manager
pub fn new() -> EthashManager {
EthashManager {
lights: Mutex::new(LruCache::new(2))
}
}
/// 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.lights.lock().unwrap();
match lights.get_mut(&epoch).map(|l| l.clone()) {
None => {
let light = match Light::from_file(block_number) {
Ok(light) => Arc::new(light),
Err(e) => {
debug!("Light cache file not found for {}:{}", block_number, e);
let light = Light::new(block_number);
if let Err(e) = light.to_file() {
warn!("Light cache file write error: {}", e);
}
Arc::new(light)
}
};
lights.insert(epoch, light.clone());
light
}
Some(light) => light
}
};
light.compute(header_hash, nonce)
}
}