openethereum/ethcore/light/src/client/mod.rs

635 lines
17 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/>.
//! Light client implementation. Stores data from light sync
use std::sync::{Weak, Arc};
use ethcore::block_status::BlockStatus;
use ethcore::client::{ClientReport, EnvInfo};
use ethcore::engines::{epoch, EthEngine, EpochChange, EpochTransition, Proof};
use ethcore::machine::EthereumMachine;
use ethcore::error::BlockImportError;
use ethcore::ids::BlockId;
use ethcore::header::{BlockNumber, Header};
use ethcore::verification::queue::{self, HeaderQueue};
use ethcore::blockchain_info::BlockChainInfo;
use ethcore::spec::Spec;
use ethcore::service::ClientIoMessage;
use ethcore::encoded;
use io::IoChannel;
use parking_lot::{Mutex, RwLock};
use bigint::prelude::U256;
use bigint::hash::H256;
use futures::{IntoFuture, Future};
use kvdb::{self, KeyValueDB};
use kvdb_rocksdb::CompactionProfile;
use self::fetch::ChainDataFetcher;
use self::header_chain::{AncestryIter, HeaderChain};
use cache::Cache;
pub use self::service::Service;
mod header_chain;
mod service;
pub mod fetch;
/// Configuration for the light client.
#[derive(Debug, Clone)]
pub struct Config {
/// Verification queue config.
pub queue: queue::Config,
/// Chain column in database.
pub chain_column: Option<u32>,
/// Database cache size. `None` => rocksdb default.
pub db_cache_size: Option<usize>,
/// State db compaction profile
pub db_compaction: CompactionProfile,
/// Should db have WAL enabled?
pub db_wal: bool,
/// Should it do full verification of blocks?
pub verify_full: bool,
/// Should it check the seal of blocks?
pub check_seal: bool,
}
impl Default for Config {
fn default() -> Config {
Config {
queue: Default::default(),
chain_column: None,
db_cache_size: None,
db_compaction: CompactionProfile::default(),
db_wal: true,
verify_full: true,
check_seal: true,
}
}
}
/// Trait for interacting with the header chain abstractly.
pub trait LightChainClient: Send + Sync {
/// Adds a new `LightChainNotify` listener.
fn add_listener(&self, listener: Weak<LightChainNotify>);
/// Get chain info.
fn chain_info(&self) -> BlockChainInfo;
/// Queue header to be verified. Required that all headers queued have their
/// parent queued prior.
fn queue_header(&self, header: Header) -> Result<H256, BlockImportError>;
/// Attempt to get a block hash by block id.
fn block_hash(&self, id: BlockId) -> Option<H256>;
/// Attempt to get block header by block id.
fn block_header(&self, id: BlockId) -> Option<encoded::Header>;
/// Get the best block header.
fn best_block_header(&self) -> encoded::Header;
/// Get a block's chain score by ID.
fn score(&self, id: BlockId) -> Option<U256>;
/// Get an iterator over a block and its ancestry.
fn ancestry_iter<'a>(&'a self, start: BlockId) -> Box<Iterator<Item=encoded::Header> + 'a>;
/// Get the signing chain ID.
fn signing_chain_id(&self) -> Option<u64>;
/// Get environment info for execution at a given block.
/// Fails if that block's header is not stored.
fn env_info(&self, id: BlockId) -> Option<EnvInfo>;
/// Get a handle to the consensus engine.
fn engine(&self) -> &Arc<EthEngine>;
/// Query whether a block is known.
fn is_known(&self, hash: &H256) -> bool;
/// Clear the queue.
fn clear_queue(&self);
/// Flush the queue.
fn flush_queue(&self);
/// Get queue info.
fn queue_info(&self) -> queue::QueueInfo;
/// Get the `i`th CHT root.
fn cht_root(&self, i: usize) -> Option<H256>;
/// Get the EIP-86 transition block number.
fn eip86_transition(&self) -> BlockNumber;
/// Get a report of import activity since the last call.
fn report(&self) -> ClientReport;
}
/// An actor listening to light chain events.
pub trait LightChainNotify: Send + Sync {
/// Notifies about imported headers.
fn new_headers(&self, good: &[H256]);
}
/// Something which can be treated as a `LightChainClient`.
pub trait AsLightClient {
/// The kind of light client this can be treated as.
type Client: LightChainClient;
/// Access the underlying light client.
fn as_light_client(&self) -> &Self::Client;
}
impl<T: LightChainClient> AsLightClient for T {
type Client = Self;
fn as_light_client(&self) -> &Self { self }
}
/// Light client implementation.
pub struct Client<T> {
queue: HeaderQueue,
engine: Arc<EthEngine>,
chain: HeaderChain,
report: RwLock<ClientReport>,
import_lock: Mutex<()>,
db: Arc<KeyValueDB>,
listeners: RwLock<Vec<Weak<LightChainNotify>>>,
fetcher: T,
verify_full: bool,
}
impl<T: ChainDataFetcher> Client<T> {
/// Create a new `Client`.
pub fn new(
config: Config,
db: Arc<KeyValueDB>,
chain_col: Option<u32>,
spec: &Spec,
fetcher: T,
io_channel: IoChannel<ClientIoMessage>,
cache: Arc<Mutex<Cache>>
) -> Result<Self, kvdb::Error> {
Ok(Client {
queue: HeaderQueue::new(config.queue, spec.engine.clone(), io_channel, config.check_seal),
engine: spec.engine.clone(),
chain: HeaderChain::new(db.clone(), chain_col, &spec, cache)?,
report: RwLock::new(ClientReport::default()),
import_lock: Mutex::new(()),
db: db,
listeners: RwLock::new(vec![]),
fetcher: fetcher,
verify_full: config.verify_full,
})
}
/// Adds a new `LightChainNotify` listener.
pub fn add_listener(&self, listener: Weak<LightChainNotify>) {
self.listeners.write().push(listener);
}
/// Create a new `Client` backed purely in-memory.
/// This will ignore all database options in the configuration.
pub fn in_memory(
config: Config,
spec: &Spec,
fetcher: T,
io_channel: IoChannel<ClientIoMessage>,
cache: Arc<Mutex<Cache>>
) -> Self {
let db = ::kvdb_memorydb::create(0);
Client::new(
config,
Arc::new(db),
None,
spec,
fetcher,
io_channel,
cache
).expect("New DB creation infallible; qed")
}
/// Import a header to the queue for additional verification.
pub fn import_header(&self, header: Header) -> Result<H256, BlockImportError> {
self.queue.import(header).map_err(Into::into)
}
/// Inquire about the status of a given header.
pub fn status(&self, hash: &H256) -> BlockStatus {
match self.queue.status(hash) {
queue::Status::Unknown => self.chain.status(hash),
other => other.into(),
}
}
/// Get the chain info.
pub fn chain_info(&self) -> BlockChainInfo {
let best_hdr = self.chain.best_header();
let best_td = self.chain.best_block().total_difficulty;
let first_block = self.chain.first_block();
let genesis_hash = self.chain.genesis_hash();
BlockChainInfo {
total_difficulty: best_td,
pending_total_difficulty: best_td + self.queue.total_difficulty(),
genesis_hash: genesis_hash,
best_block_hash: best_hdr.hash(),
best_block_number: best_hdr.number(),
best_block_timestamp: best_hdr.timestamp(),
ancient_block_hash: if first_block.is_some() { Some(genesis_hash) } else { None },
ancient_block_number: if first_block.is_some() { Some(0) } else { None },
first_block_hash: first_block.as_ref().map(|first| first.hash),
first_block_number: first_block.as_ref().map(|first| first.number),
}
}
/// Get the header queue info.
pub fn queue_info(&self) -> queue::QueueInfo {
self.queue.queue_info()
}
/// Attempt to get a block hash by block id.
pub fn block_hash(&self, id: BlockId) -> Option<H256> {
self.chain.block_hash(id)
}
/// Get a block header by Id.
pub fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
self.chain.block_header(id)
}
/// Get the best block header.
pub fn best_block_header(&self) -> encoded::Header {
self.chain.best_header()
}
/// Get a block's chain score.
pub fn score(&self, id: BlockId) -> Option<U256> {
self.chain.score(id)
}
/// Get an iterator over a block and its ancestry.
pub fn ancestry_iter(&self, start: BlockId) -> AncestryIter {
self.chain.ancestry_iter(start)
}
/// Get the signing chain id.
pub fn signing_chain_id(&self) -> Option<u64> {
self.engine.signing_chain_id(&self.latest_env_info())
}
/// Flush the header queue.
pub fn flush_queue(&self) {
self.queue.flush()
}
/// Get the `i`th CHT root.
pub fn cht_root(&self, i: usize) -> Option<H256> {
self.chain.cht_root(i)
}
/// Import a set of pre-verified headers from the queue.
pub fn import_verified(&self) {
const MAX: usize = 256;
let _lock = self.import_lock.lock();
let mut bad = Vec::new();
let mut good = Vec::new();
for verified_header in self.queue.drain(MAX) {
let (num, hash) = (verified_header.number(), verified_header.hash());
trace!(target: "client", "importing block {}", num);
if self.verify_full && !self.check_header(&mut bad, &verified_header) {
continue
}
let write_proof_result = match self.check_epoch_signal(&verified_header) {
Ok(Some(proof)) => self.write_pending_proof(&verified_header, proof),
Ok(None) => Ok(()),
Err(e) =>
panic!("Unable to fetch epoch transition proof: {:?}", e),
};
if let Err(e) = write_proof_result {
warn!(target: "client", "Error writing pending transition proof to DB: {:?} \
The node may not be able to synchronize further.", e);
}
let epoch_proof = self.engine.is_epoch_end(
&verified_header,
&|h| self.chain.block_header(BlockId::Hash(h)).map(|hdr| hdr.decode()),
&|h| self.chain.pending_transition(h),
);
let mut tx = self.db.transaction();
let pending = match self.chain.insert(&mut tx, verified_header, epoch_proof) {
Ok(pending) => {
good.push(hash);
self.report.write().blocks_imported += 1;
pending
}
Err(e) => {
debug!(target: "client", "Error importing header {:?}: {:?}", (num, hash), e);
bad.push(hash);
continue;
}
};
self.db.write_buffered(tx);
self.chain.apply_pending(pending);
}
if let Err(e) = self.db.flush() {
panic!("Database flush failed: {}. Check disk health and space.", e);
}
self.queue.mark_as_bad(&bad);
self.queue.mark_as_good(&good);
self.notify(|listener| listener.new_headers(&good));
}
/// Get a report about blocks imported.
pub fn report(&self) -> ClientReport {
self.report.read().clone()
}
/// Get blockchain mem usage in bytes.
pub fn chain_mem_used(&self) -> usize {
use heapsize::HeapSizeOf;
self.chain.heap_size_of_children()
}
/// Get a handle to the verification engine.
pub fn engine(&self) -> &Arc<EthEngine> {
&self.engine
}
/// Get the latest environment info.
pub fn latest_env_info(&self) -> EnvInfo {
self.env_info(BlockId::Latest)
.expect("Best block header and recent hashes always stored; qed")
}
/// Get environment info for a given block.
pub fn env_info(&self, id: BlockId) -> Option<EnvInfo> {
let header = match self.block_header(id) {
Some(hdr) => hdr,
None => return None,
};
Some(EnvInfo {
number: header.number(),
author: header.author(),
timestamp: header.timestamp(),
difficulty: header.difficulty(),
last_hashes: self.build_last_hashes(header.parent_hash()),
gas_used: Default::default(),
gas_limit: header.gas_limit(),
})
}
fn build_last_hashes(&self, mut parent_hash: H256) -> Arc<Vec<H256>> {
let mut v = Vec::with_capacity(256);
for _ in 0..255 {
v.push(parent_hash);
match self.block_header(BlockId::Hash(parent_hash)) {
Some(header) => parent_hash = header.hash(),
None => break,
}
}
Arc::new(v)
}
fn notify<F: Fn(&LightChainNotify)>(&self, f: F) {
for listener in &*self.listeners.read() {
if let Some(listener) = listener.upgrade() {
f(&*listener)
}
}
}
// return false if should skip, true otherwise. may push onto bad if
// should skip.
fn check_header(&self, bad: &mut Vec<H256>, verified_header: &Header) -> bool {
let hash = verified_header.hash();
let parent_header = match self.chain.block_header(BlockId::Hash(*verified_header.parent_hash())) {
Some(header) => header,
None => {
trace!(target: "client", "No parent for block ({}, {})",
verified_header.number(), hash);
return false // skip import of block with missing parent.
}
};
// Verify Block Family
let verify_family_result = self.engine.verify_block_family(&verified_header, &parent_header.decode());
if let Err(e) = verify_family_result {
warn!(target: "client", "Stage 3 block verification failed for #{} ({})\nError: {:?}",
verified_header.number(), verified_header.hash(), e);
bad.push(hash);
return false;
};
// "external" verification.
let verify_external_result = self.engine.verify_block_external(&verified_header);
if let Err(e) = verify_external_result {
warn!(target: "client", "Stage 4 block verification failed for #{} ({})\nError: {:?}",
verified_header.number(), verified_header.hash(), e);
bad.push(hash);
return false;
};
true
}
fn check_epoch_signal(&self, verified_header: &Header) -> Result<Option<Proof<EthereumMachine>>, T::Error> {
use ethcore::machine::{AuxiliaryRequest, AuxiliaryData};
let mut block: Option<Vec<u8>> = None;
let mut receipts: Option<Vec<_>> = None;
loop {
let is_signal = {
let auxiliary = AuxiliaryData {
bytes: block.as_ref().map(|x| &x[..]),
receipts: receipts.as_ref().map(|x| &x[..]),
};
self.engine.signals_epoch_end(verified_header, auxiliary)
};
// check with any auxiliary data fetched so far
match is_signal {
EpochChange::No => return Ok(None),
EpochChange::Yes(proof) => return Ok(Some(proof)),
EpochChange::Unsure(unsure) => {
let (b, r) = match unsure {
AuxiliaryRequest::Body =>
(Some(self.fetcher.block_body(verified_header)), None),
AuxiliaryRequest::Receipts =>
(None, Some(self.fetcher.block_receipts(verified_header))),
AuxiliaryRequest::Both => (
Some(self.fetcher.block_body(verified_header)),
Some(self.fetcher.block_receipts(verified_header)),
),
};
if let Some(b) = b {
block = Some(b.into_future().wait()?.into_inner());
}
if let Some(r) = r {
receipts = Some(r.into_future().wait()?);
}
}
}
}
}
// attempts to fetch the epoch proof from the network until successful.
fn write_pending_proof(&self, header: &Header, proof: Proof<EthereumMachine>) -> Result<(), T::Error> {
let proof = match proof {
Proof::Known(known) => known,
Proof::WithState(state_dependent) => {
self.fetcher.epoch_transition(
header.hash(),
self.engine.clone(),
state_dependent
).into_future().wait()?
}
};
let mut batch = self.db.transaction();
self.chain.insert_pending_transition(&mut batch, header.hash(), epoch::PendingTransition {
proof: proof,
});
self.db.write_buffered(batch);
Ok(())
}
}
impl<T: ChainDataFetcher> LightChainClient for Client<T> {
fn add_listener(&self, listener: Weak<LightChainNotify>) {
Client::add_listener(self, listener)
}
fn chain_info(&self) -> BlockChainInfo { Client::chain_info(self) }
fn queue_header(&self, header: Header) -> Result<H256, BlockImportError> {
self.import_header(header)
}
fn block_hash(&self, id: BlockId) -> Option<H256> {
Client::block_hash(self, id)
}
fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
Client::block_header(self, id)
}
fn best_block_header(&self) -> encoded::Header {
Client::best_block_header(self)
}
fn score(&self, id: BlockId) -> Option<U256> {
Client::score(self, id)
}
fn ancestry_iter<'a>(&'a self, start: BlockId) -> Box<Iterator<Item=encoded::Header> + 'a> {
Box::new(Client::ancestry_iter(self, start))
}
fn signing_chain_id(&self) -> Option<u64> {
Client::signing_chain_id(self)
}
fn env_info(&self, id: BlockId) -> Option<EnvInfo> {
Client::env_info(self, id)
}
fn engine(&self) -> &Arc<EthEngine> {
Client::engine(self)
}
fn is_known(&self, hash: &H256) -> bool {
self.status(hash) == BlockStatus::InChain
}
fn clear_queue(&self) {
self.queue.clear()
}
fn flush_queue(&self) {
Client::flush_queue(self);
}
fn queue_info(&self) -> queue::QueueInfo {
self.queue.queue_info()
}
fn cht_root(&self, i: usize) -> Option<H256> {
Client::cht_root(self, i)
}
fn eip86_transition(&self) -> BlockNumber {
self.engine().params().eip86_transition
}
fn report(&self) -> ClientReport {
Client::report(self)
}
}
impl<T: ChainDataFetcher> ::ethcore::client::EngineClient for Client<T> {
fn update_sealing(&self) { }
fn submit_seal(&self, _block_hash: H256, _seal: Vec<Vec<u8>>) { }
fn broadcast_consensus_message(&self, _message: Vec<u8>) { }
fn epoch_transition_for(&self, parent_hash: H256) -> Option<EpochTransition> {
self.chain.epoch_transition_for(parent_hash).map(|(hdr, proof)| EpochTransition {
block_hash: hdr.hash(),
block_number: hdr.number(),
proof: proof,
})
}
fn chain_info(&self) -> BlockChainInfo {
Client::chain_info(self)
}
fn as_full_client(&self) -> Option<&::ethcore::client::BlockChainClient> {
None
}
fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
self.block_header(id).map(|hdr| hdr.number())
}
}