70 lines
2.3 KiB
Rust
70 lines
2.3 KiB
Rust
// Copyright 2015-2017 Parity Technologies (UK) Ltd.
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// This file is part of Parity.
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// Parity is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// Parity is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with Parity. If not, see <http://www.gnu.org/licenses/>.
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//! Helper for ancient block import.
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use std::sync::Arc;
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use blockchain::BlockChain;
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use engines::{EthEngine, EpochVerifier};
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use header::Header;
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use machine::EthereumMachine;
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use rand::Rng;
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use parking_lot::RwLock;
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// do "heavy" verification on ~1/50 blocks, randomly sampled.
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const HEAVY_VERIFY_RATE: f32 = 0.02;
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/// Ancient block verifier: import an ancient sequence of blocks in order from a starting
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/// epoch.
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pub struct AncientVerifier {
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cur_verifier: RwLock<Box<EpochVerifier<EthereumMachine>>>,
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engine: Arc<EthEngine>,
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}
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impl AncientVerifier {
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/// Create a new ancient block verifier with the given engine and initial verifier.
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pub fn new(engine: Arc<EthEngine>, start_verifier: Box<EpochVerifier<EthereumMachine>>) -> Self {
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AncientVerifier {
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cur_verifier: RwLock::new(start_verifier),
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engine: engine,
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}
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}
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/// Verify the next block header, randomly choosing whether to do heavy or light
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/// verification. If the block is the end of an epoch, updates the epoch verifier.
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pub fn verify<R: Rng>(
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&self,
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rng: &mut R,
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header: &Header,
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chain: &BlockChain,
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) -> Result<(), ::error::Error> {
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match rng.gen::<f32>() <= HEAVY_VERIFY_RATE {
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true => self.cur_verifier.read().verify_heavy(header)?,
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false => self.cur_verifier.read().verify_light(header)?,
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}
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// ancient import will only use transitions obtained from the snapshot.
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if let Some(transition) = chain.epoch_transition(header.number(), header.hash()) {
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let v = self.engine.epoch_verifier(&header, &transition.proof).known_confirmed()?;
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*self.cur_verifier.write() = v;
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}
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Ok(())
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}
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}
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