openethereum/ethcore/src/blockchain/blockchain.rs
2016-06-20 13:42:04 +03:00

1166 lines
44 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/>.
//! Blockchain database.
use std::sync::atomic::{AtomicUsize, Ordering as AtomicOrder};
use bloomchain as bc;
use util::*;
use header::*;
use super::extras::*;
use transaction::*;
use views::*;
use receipt::Receipt;
use blooms::{Bloom, BloomGroup};
use blockchain::block_info::{BlockInfo, BlockLocation, BranchBecomingCanonChainData};
use blockchain::best_block::BestBlock;
use types::tree_route::TreeRoute;
use blockchain::update::ExtrasUpdate;
use blockchain::{CacheSize, ImportRoute, Config};
use db::{Writable, Readable, CacheUpdatePolicy};
const LOG_BLOOMS_LEVELS: usize = 3;
const LOG_BLOOMS_ELEMENTS_PER_INDEX: usize = 16;
/// Interface for querying blocks by hash and by number.
pub trait BlockProvider {
/// Returns true if the given block is known
/// (though not necessarily a part of the canon chain).
fn is_known(&self, hash: &H256) -> bool;
/// Get raw block data
fn block(&self, hash: &H256) -> Option<Bytes>;
/// Get the familial details concerning a block.
fn block_details(&self, hash: &H256) -> Option<BlockDetails>;
/// Get the hash of given block's number.
fn block_hash(&self, index: BlockNumber) -> Option<H256>;
/// Get the address of transaction with given hash.
fn transaction_address(&self, hash: &H256) -> Option<TransactionAddress>;
/// Get receipts of block with given hash.
fn block_receipts(&self, hash: &H256) -> Option<BlockReceipts>;
/// Get the partial-header of a block.
fn block_header(&self, hash: &H256) -> Option<Header> {
self.block(hash).map(|bytes| BlockView::new(&bytes).header())
}
/// Get a list of uncles for a given block.
/// Returns None if block does not exist.
fn uncles(&self, hash: &H256) -> Option<Vec<Header>> {
self.block(hash).map(|bytes| BlockView::new(&bytes).uncles())
}
/// Get a list of uncle hashes for a given block.
/// Returns None if block does not exist.
fn uncle_hashes(&self, hash: &H256) -> Option<Vec<H256>> {
self.block(hash).map(|bytes| BlockView::new(&bytes).uncle_hashes())
}
/// Get the number of given block's hash.
fn block_number(&self, hash: &H256) -> Option<BlockNumber> {
self.block(hash).map(|bytes| BlockView::new(&bytes).header_view().number())
}
/// Get transaction with given transaction hash.
fn transaction(&self, address: &TransactionAddress) -> Option<LocalizedTransaction> {
self.block(&address.block_hash).and_then(|bytes| BlockView::new(&bytes).localized_transaction_at(address.index))
}
/// Get transaction receipt.
fn transaction_receipt(&self, address: &TransactionAddress) -> Option<Receipt> {
self.block_receipts(&address.block_hash).and_then(|br| br.receipts.into_iter().nth(address.index))
}
/// Get a list of transactions for a given block.
/// Returns None if block does not exist.
fn transactions(&self, hash: &H256) -> Option<Vec<LocalizedTransaction>> {
self.block(hash).map(|bytes| BlockView::new(&bytes).localized_transactions())
}
/// Returns reference to genesis hash.
fn genesis_hash(&self) -> H256 {
self.block_hash(0).expect("Genesis hash should always exist")
}
/// Returns the header of the genesis block.
fn genesis_header(&self) -> Header {
self.block_header(&self.genesis_hash()).unwrap()
}
/// Returns numbers of blocks containing given bloom.
fn blocks_with_bloom(&self, bloom: &H2048, from_block: BlockNumber, to_block: BlockNumber) -> Vec<BlockNumber>;
}
#[derive(Debug, Hash, Eq, PartialEq, Clone)]
enum CacheID {
Block(H256),
BlockDetails(H256),
BlockHashes(BlockNumber),
TransactionAddresses(H256),
BlocksBlooms(LogGroupPosition),
BlockReceipts(H256),
}
struct CacheManager {
cache_usage: VecDeque<HashSet<CacheID>>,
in_use: HashSet<CacheID>,
}
impl bc::group::BloomGroupDatabase for BlockChain {
fn blooms_at(&self, position: &bc::group::GroupPosition) -> Option<bc::group::BloomGroup> {
let position = LogGroupPosition::from(position.clone());
self.note_used(CacheID::BlocksBlooms(position.clone()));
self.extras_db.read_with_cache(&self.blocks_blooms, &position).map(Into::into)
}
}
/// Structure providing fast access to blockchain data.
///
/// **Does not do input data verification.**
pub struct BlockChain {
// All locks must be captured in the order declared here.
pref_cache_size: AtomicUsize,
max_cache_size: AtomicUsize,
blooms_config: bc::Config,
best_block: RwLock<BestBlock>,
// block cache
blocks: RwLock<HashMap<H256, Bytes>>,
// extra caches
block_details: RwLock<HashMap<H256, BlockDetails>>,
block_hashes: RwLock<HashMap<BlockNumber, H256>>,
transaction_addresses: RwLock<HashMap<H256, TransactionAddress>>,
blocks_blooms: RwLock<HashMap<LogGroupPosition, BloomGroup>>,
block_receipts: RwLock<HashMap<H256, BlockReceipts>>,
extras_db: Database,
blocks_db: Database,
cache_man: RwLock<CacheManager>,
insert_lock: Mutex<()>
}
impl BlockProvider for BlockChain {
/// Returns true if the given block is known
/// (though not necessarily a part of the canon chain).
fn is_known(&self, hash: &H256) -> bool {
self.extras_db.exists_with_cache(&self.block_details, hash)
}
/// Get raw block data
fn block(&self, hash: &H256) -> Option<Bytes> {
{
let read = self.blocks.read().unwrap();
if let Some(v) = read.get(hash) {
return Some(v.clone());
}
}
let opt = self.blocks_db.get(hash)
.expect("Low level database error. Some issue with disk?");
self.note_used(CacheID::Block(hash.clone()));
match opt {
Some(b) => {
let bytes: Bytes = b.to_vec();
let mut write = self.blocks.write().unwrap();
write.insert(hash.clone(), bytes.clone());
Some(bytes)
},
None => None
}
}
/// Get the familial details concerning a block.
fn block_details(&self, hash: &H256) -> Option<BlockDetails> {
self.note_used(CacheID::BlockDetails(hash.clone()));
self.extras_db.read_with_cache(&self.block_details, hash)
}
/// Get the hash of given block's number.
fn block_hash(&self, index: BlockNumber) -> Option<H256> {
self.note_used(CacheID::BlockHashes(index));
self.extras_db.read_with_cache(&self.block_hashes, &index)
}
/// Get the address of transaction with given hash.
fn transaction_address(&self, hash: &H256) -> Option<TransactionAddress> {
self.note_used(CacheID::TransactionAddresses(hash.clone()));
self.extras_db.read_with_cache(&self.transaction_addresses, hash)
}
/// Get receipts of block with given hash.
fn block_receipts(&self, hash: &H256) -> Option<BlockReceipts> {
self.note_used(CacheID::BlockReceipts(hash.clone()));
self.extras_db.read_with_cache(&self.block_receipts, hash)
}
/// Returns numbers of blocks containing given bloom.
fn blocks_with_bloom(&self, bloom: &H2048, from_block: BlockNumber, to_block: BlockNumber) -> Vec<BlockNumber> {
let range = from_block as bc::Number..to_block as bc::Number;
let chain = bc::group::BloomGroupChain::new(self.blooms_config, self);
chain.with_bloom(&range, &Bloom::from(bloom.clone()).into())
.into_iter()
.map(|b| b as BlockNumber)
.collect()
}
}
const COLLECTION_QUEUE_SIZE: usize = 8;
pub struct AncestryIter<'a> {
current: H256,
chain: &'a BlockChain,
}
impl<'a> Iterator for AncestryIter<'a> {
type Item = H256;
fn next(&mut self) -> Option<H256> {
if self.current.is_zero() {
Option::None
} else {
let mut n = self.chain.block_details(&self.current).unwrap().parent;
mem::swap(&mut self.current, &mut n);
Some(n)
}
}
}
impl BlockChain {
/// Create new instance of blockchain from given Genesis
pub fn new(config: Config, genesis: &[u8], path: &Path) -> BlockChain {
// open extras db
let mut extras_path = path.to_path_buf();
extras_path.push("extras");
let extras_db = match config.db_cache_size {
None => Database::open_default(extras_path.to_str().unwrap()).unwrap(),
Some(cache_size) => Database::open(
&DatabaseConfig::with_cache(cache_size/2),
extras_path.to_str().unwrap()).unwrap(),
};
// open blocks db
let mut blocks_path = path.to_path_buf();
blocks_path.push("blocks");
let blocks_db = match config.db_cache_size {
None => Database::open_default(blocks_path.to_str().unwrap()).unwrap(),
Some(cache_size) => Database::open(
&DatabaseConfig::with_cache(cache_size/2),
blocks_path.to_str().unwrap()).unwrap(),
};
let mut cache_man = CacheManager{cache_usage: VecDeque::new(), in_use: HashSet::new()};
(0..COLLECTION_QUEUE_SIZE).foreach(|_| cache_man.cache_usage.push_back(HashSet::new()));
let bc = BlockChain {
pref_cache_size: AtomicUsize::new(config.pref_cache_size),
max_cache_size: AtomicUsize::new(config.max_cache_size),
blooms_config: bc::Config {
levels: LOG_BLOOMS_LEVELS,
elements_per_index: LOG_BLOOMS_ELEMENTS_PER_INDEX,
},
best_block: RwLock::new(BestBlock::default()),
blocks: RwLock::new(HashMap::new()),
block_details: RwLock::new(HashMap::new()),
block_hashes: RwLock::new(HashMap::new()),
transaction_addresses: RwLock::new(HashMap::new()),
blocks_blooms: RwLock::new(HashMap::new()),
block_receipts: RwLock::new(HashMap::new()),
extras_db: extras_db,
blocks_db: blocks_db,
cache_man: RwLock::new(cache_man),
insert_lock: Mutex::new(()),
};
// load best block
let best_block_hash = match bc.extras_db.get(b"best").unwrap() {
Some(best) => H256::from_slice(&best),
None => {
// best block does not exist
// we need to insert genesis into the cache
let block = BlockView::new(genesis);
let header = block.header_view();
let hash = block.sha3();
let details = BlockDetails {
number: header.number(),
total_difficulty: header.difficulty(),
parent: header.parent_hash(),
children: vec![]
};
bc.blocks_db.put(&hash, genesis).unwrap();
let batch = DBTransaction::new();
batch.write(&hash, &details);
batch.write(&header.number(), &hash);
batch.put(b"best", &hash).unwrap();
bc.extras_db.write(batch).unwrap();
hash
}
};
{
let mut best_block = bc.best_block.write().unwrap();
best_block.number = bc.block_number(&best_block_hash).unwrap();
best_block.total_difficulty = bc.block_details(&best_block_hash).unwrap().total_difficulty;
best_block.hash = best_block_hash;
}
bc
}
/// Set the cache configuration.
pub fn configure_cache(&self, pref_cache_size: usize, max_cache_size: usize) {
self.pref_cache_size.store(pref_cache_size, AtomicOrder::Relaxed);
self.max_cache_size.store(max_cache_size, AtomicOrder::Relaxed);
}
/// Returns a tree route between `from` and `to`, which is a tuple of:
///
/// - a vector of hashes of all blocks, ordered from `from` to `to`.
///
/// - common ancestor of these blocks.
///
/// - an index where best common ancestor would be
///
/// 1.) from newer to older
///
/// - bc: `A1 -> A2 -> A3 -> A4 -> A5`
/// - from: A5, to: A4
/// - route:
///
/// ```json
/// { blocks: [A5], ancestor: A4, index: 1 }
/// ```
///
/// 2.) from older to newer
///
/// - bc: `A1 -> A2 -> A3 -> A4 -> A5`
/// - from: A3, to: A4
/// - route:
///
/// ```json
/// { blocks: [A4], ancestor: A3, index: 0 }
/// ```
///
/// 3.) fork:
///
/// - bc:
///
/// ```text
/// A1 -> A2 -> A3 -> A4
/// -> B3 -> B4
/// ```
/// - from: B4, to: A4
/// - route:
///
/// ```json
/// { blocks: [B4, B3, A3, A4], ancestor: A2, index: 2 }
/// ```
pub fn tree_route(&self, from: H256, to: H256) -> TreeRoute {
let mut from_branch = vec![];
let mut to_branch = vec![];
let mut from_details = self.block_details(&from).expect(&format!("0. Expected to find details for block {:?}", from));
let mut to_details = self.block_details(&to).expect(&format!("1. Expected to find details for block {:?}", to));
let mut current_from = from;
let mut current_to = to;
// reset from && to to the same level
while from_details.number > to_details.number {
from_branch.push(current_from);
current_from = from_details.parent.clone();
from_details = self.block_details(&from_details.parent).expect(&format!("2. Expected to find details for block {:?}", from_details.parent));
}
while to_details.number > from_details.number {
to_branch.push(current_to);
current_to = to_details.parent.clone();
to_details = self.block_details(&to_details.parent).expect(&format!("3. Expected to find details for block {:?}", to_details.parent));
}
assert_eq!(from_details.number, to_details.number);
// move to shared parent
while current_from != current_to {
from_branch.push(current_from);
current_from = from_details.parent.clone();
from_details = self.block_details(&from_details.parent).expect(&format!("4. Expected to find details for block {:?}", from_details.parent));
to_branch.push(current_to);
current_to = to_details.parent.clone();
to_details = self.block_details(&to_details.parent).expect(&format!("5. Expected to find details for block {:?}", from_details.parent));
}
let index = from_branch.len();
from_branch.extend(to_branch.into_iter().rev());
TreeRoute {
blocks: from_branch,
ancestor: current_from,
index: index
}
}
#[cfg_attr(feature="dev", allow(similar_names))]
/// Inserts the block into backing cache database.
/// Expects the block to be valid and already verified.
/// If the block is already known, does nothing.
pub fn insert_block(&self, bytes: &[u8], receipts: Vec<Receipt>) -> ImportRoute {
// create views onto rlp
let block = BlockView::new(bytes);
let header = block.header_view();
let hash = header.sha3();
if self.is_known(&hash) {
return ImportRoute::none();
}
let _lock = self.insert_lock.lock();
// store block in db
self.blocks_db.put(&hash, &bytes).unwrap();
let info = self.block_info(bytes);
self.apply_update(ExtrasUpdate {
block_hashes: self.prepare_block_hashes_update(bytes, &info),
block_details: self.prepare_block_details_update(bytes, &info),
block_receipts: self.prepare_block_receipts_update(receipts, &info),
transactions_addresses: self.prepare_transaction_addresses_update(bytes, &info),
blocks_blooms: self.prepare_block_blooms_update(bytes, &info),
info: info.clone(),
});
ImportRoute::from(info)
}
/// Applies extras update.
fn apply_update(&self, update: ExtrasUpdate) {
let batch = DBTransaction::new();
batch.put(b"best", &update.info.hash).unwrap();
{
for hash in update.block_details.keys().cloned() {
self.note_used(CacheID::BlockDetails(hash));
}
let mut write_details = self.block_details.write().unwrap();
batch.extend_with_cache(write_details.deref_mut(), update.block_details, CacheUpdatePolicy::Overwrite);
}
{
let mut write_receipts = self.block_receipts.write().unwrap();
batch.extend_with_cache(write_receipts.deref_mut(), update.block_receipts, CacheUpdatePolicy::Remove);
}
{
let mut write_blocks_blooms = self.blocks_blooms.write().unwrap();
batch.extend_with_cache(write_blocks_blooms.deref_mut(), update.blocks_blooms, CacheUpdatePolicy::Remove);
}
// These cached values must be updated last and togeterh
{
let mut best_block = self.best_block.write().unwrap();
let mut write_hashes = self.block_hashes.write().unwrap();
let mut write_txs = self.transaction_addresses.write().unwrap();
// update best block
match update.info.location {
BlockLocation::Branch => (),
_ => {
*best_block = BestBlock {
hash: update.info.hash,
number: update.info.number,
total_difficulty: update.info.total_difficulty
};
}
}
batch.extend_with_cache(write_hashes.deref_mut(), update.block_hashes, CacheUpdatePolicy::Remove);
batch.extend_with_cache(write_txs.deref_mut(), update.transactions_addresses, CacheUpdatePolicy::Remove);
// update extras database
self.extras_db.write(batch).unwrap();
}
}
/// Iterator that lists `first` and then all of `first`'s ancestors, by hash.
pub fn ancestry_iter(&self, first: H256) -> Option<AncestryIter> {
if self.is_known(&first) {
Some(AncestryIter {
current: first,
chain: &self,
})
} else {
None
}
}
/// Given a block's `parent`, find every block header which represents a valid possible uncle.
pub fn find_uncle_headers(&self, parent: &H256, uncle_generations: usize) -> Option<Vec<Header>> {
self.find_uncle_hashes(parent, uncle_generations).map(|v| v.into_iter().filter_map(|h| self.block_header(&h)).collect())
}
/// Given a block's `parent`, find every block hash which represents a valid possible uncle.
pub fn find_uncle_hashes(&self, parent: &H256, uncle_generations: usize) -> Option<Vec<H256>> {
if !self.is_known(parent) { return None; }
let mut excluded = HashSet::new();
for a in self.ancestry_iter(parent.clone()).unwrap().take(uncle_generations) {
excluded.extend(self.uncle_hashes(&a).unwrap().into_iter());
excluded.insert(a);
}
let mut ret = Vec::new();
for a in self.ancestry_iter(parent.clone()).unwrap().skip(1).take(uncle_generations) {
ret.extend(self.block_details(&a).unwrap().children.iter()
.filter(|h| !excluded.contains(h))
);
}
Some(ret)
}
/// Get inserted block info which is critical to prepare extras updates.
fn block_info(&self, block_bytes: &[u8]) -> BlockInfo {
let block = BlockView::new(block_bytes);
let header = block.header_view();
let hash = block.sha3();
let number = header.number();
let parent_hash = header.parent_hash();
let parent_details = self.block_details(&parent_hash).expect(format!("Invalid parent hash: {:?}", parent_hash).as_ref());
let total_difficulty = parent_details.total_difficulty + header.difficulty();
let is_new_best = total_difficulty > self.best_block_total_difficulty();
BlockInfo {
hash: hash,
number: number,
total_difficulty: total_difficulty,
location: if is_new_best {
// on new best block we need to make sure that all ancestors
// are moved to "canon chain"
// find the route between old best block and the new one
let best_hash = self.best_block_hash();
let route = self.tree_route(best_hash, parent_hash);
assert_eq!(number, parent_details.number + 1);
match route.blocks.len() {
0 => BlockLocation::CanonChain,
_ => {
let retracted = route.blocks.iter().take(route.index).cloned().collect::<Vec<H256>>();
BlockLocation::BranchBecomingCanonChain(BranchBecomingCanonChainData {
ancestor: route.ancestor,
enacted: route.blocks.into_iter().skip(route.index).collect(),
retracted: retracted.into_iter().rev().collect(),
})
}
}
} else {
BlockLocation::Branch
}
}
}
/// This function returns modified block hashes.
fn prepare_block_hashes_update(&self, block_bytes: &[u8], info: &BlockInfo) -> HashMap<BlockNumber, H256> {
let mut block_hashes = HashMap::new();
let block = BlockView::new(block_bytes);
let header = block.header_view();
let number = header.number();
match info.location {
BlockLocation::Branch => (),
BlockLocation::CanonChain => {
block_hashes.insert(number, info.hash.clone());
},
BlockLocation::BranchBecomingCanonChain(ref data) => {
let ancestor_number = self.block_number(&data.ancestor).unwrap();
let start_number = ancestor_number + 1;
for (index, hash) in data.enacted.iter().cloned().enumerate() {
block_hashes.insert(start_number + index as BlockNumber, hash);
}
block_hashes.insert(number, info.hash.clone());
}
}
block_hashes
}
/// This function returns modified block details.
fn prepare_block_details_update(&self, block_bytes: &[u8], info: &BlockInfo) -> HashMap<H256, BlockDetails> {
let block = BlockView::new(block_bytes);
let header = block.header_view();
let parent_hash = header.parent_hash();
// update parent
let mut parent_details = self.block_details(&parent_hash).expect(format!("Invalid parent hash: {:?}", parent_hash).as_ref());
parent_details.children.push(info.hash.clone());
// create current block details
let details = BlockDetails {
number: header.number(),
total_difficulty: info.total_difficulty,
parent: parent_hash.clone(),
children: vec![]
};
// write to batch
let mut block_details = HashMap::new();
block_details.insert(parent_hash, parent_details);
block_details.insert(info.hash.clone(), details);
block_details
}
/// This function returns modified block receipts.
fn prepare_block_receipts_update(&self, receipts: Vec<Receipt>, info: &BlockInfo) -> HashMap<H256, BlockReceipts> {
let mut block_receipts = HashMap::new();
block_receipts.insert(info.hash.clone(), BlockReceipts::new(receipts));
block_receipts
}
/// This function returns modified transaction addresses.
fn prepare_transaction_addresses_update(&self, block_bytes: &[u8], info: &BlockInfo) -> HashMap<H256, TransactionAddress> {
let block = BlockView::new(block_bytes);
let transaction_hashes = block.transaction_hashes();
transaction_hashes.into_iter()
.enumerate()
.fold(HashMap::new(), |mut acc, (i ,tx_hash)| {
acc.insert(tx_hash, TransactionAddress {
block_hash: info.hash.clone(),
index: i
});
acc
})
}
/// This functions returns modified blocks blooms.
///
/// To accelerate blooms lookups, blomms are stored in multiple
/// layers (BLOOM_LEVELS, currently 3).
/// ChainFilter is responsible for building and rebuilding these layers.
/// It returns them in HashMap, where values are Blooms and
/// keys are BloomIndexes. BloomIndex represents bloom location on one
/// of these layers.
///
/// To reduce number of queries to databse, block blooms are stored
/// in BlocksBlooms structure which contains info about several
/// (BLOOM_INDEX_SIZE, currently 16) consecutive blocks blooms.
///
/// Later, BloomIndexer is used to map bloom location on filter layer (BloomIndex)
/// to bloom location in database (BlocksBloomLocation).
///
fn prepare_block_blooms_update(&self, block_bytes: &[u8], info: &BlockInfo) -> HashMap<LogGroupPosition, BloomGroup> {
let block = BlockView::new(block_bytes);
let header = block.header_view();
let log_blooms = match info.location {
BlockLocation::Branch => HashMap::new(),
BlockLocation::CanonChain => {
let chain = bc::group::BloomGroupChain::new(self.blooms_config, self);
chain.insert(info.number as bc::Number, Bloom::from(header.log_bloom()).into())
},
BlockLocation::BranchBecomingCanonChain(ref data) => {
let ancestor_number = self.block_number(&data.ancestor).unwrap();
let start_number = ancestor_number + 1;
let range = start_number as bc::Number..self.best_block_number() as bc::Number;
let mut blooms: Vec<bc::Bloom> = data.enacted.iter()
.map(|hash| self.block(hash).unwrap())
.map(|bytes| BlockView::new(&bytes).header_view().log_bloom())
.map(Bloom::from)
.map(Into::into)
.collect();
blooms.push(Bloom::from(header.log_bloom()).into());
let chain = bc::group::BloomGroupChain::new(self.blooms_config, self);
chain.replace(&range, blooms)
}
};
log_blooms.into_iter()
.map(|p| (From::from(p.0), From::from(p.1)))
.collect()
}
/// Get best block hash.
pub fn best_block_hash(&self) -> H256 {
self.best_block.read().unwrap().hash.clone()
}
/// Get best block number.
pub fn best_block_number(&self) -> BlockNumber {
self.best_block.read().unwrap().number
}
/// Get best block total difficulty.
pub fn best_block_total_difficulty(&self) -> U256 {
self.best_block.read().unwrap().total_difficulty
}
/// Get current cache size.
pub fn cache_size(&self) -> CacheSize {
CacheSize {
blocks: self.blocks.read().unwrap().heap_size_of_children(),
block_details: self.block_details.read().unwrap().heap_size_of_children(),
transaction_addresses: self.transaction_addresses.read().unwrap().heap_size_of_children(),
blocks_blooms: self.blocks_blooms.read().unwrap().heap_size_of_children(),
block_receipts: self.block_receipts.read().unwrap().heap_size_of_children(),
}
}
/// Let the cache system know that a cacheable item has been used.
fn note_used(&self, id: CacheID) {
let mut cache_man = self.cache_man.write().unwrap();
if !cache_man.cache_usage[0].contains(&id) {
cache_man.cache_usage[0].insert(id.clone());
if cache_man.in_use.contains(&id) {
if let Some(c) = cache_man.cache_usage.iter_mut().skip(1).find(|e|e.contains(&id)) {
c.remove(&id);
}
} else {
cache_man.in_use.insert(id);
}
}
}
/// Ticks our cache system and throws out any old data.
pub fn collect_garbage(&self) {
if self.cache_size().total() < self.pref_cache_size.load(AtomicOrder::Relaxed) { return; }
for _ in 0..COLLECTION_QUEUE_SIZE {
{
let mut blocks = self.blocks.write().unwrap();
let mut block_details = self.block_details.write().unwrap();
let mut block_hashes = self.block_hashes.write().unwrap();
let mut transaction_addresses = self.transaction_addresses.write().unwrap();
let mut blocks_blooms = self.blocks_blooms.write().unwrap();
let mut block_receipts = self.block_receipts.write().unwrap();
let mut cache_man = self.cache_man.write().unwrap();
for id in cache_man.cache_usage.pop_back().unwrap().into_iter() {
cache_man.in_use.remove(&id);
match id {
CacheID::Block(h) => { blocks.remove(&h); },
CacheID::BlockDetails(h) => { block_details.remove(&h); }
CacheID::BlockHashes(h) => { block_hashes.remove(&h); }
CacheID::TransactionAddresses(h) => { transaction_addresses.remove(&h); }
CacheID::BlocksBlooms(h) => { blocks_blooms.remove(&h); }
CacheID::BlockReceipts(h) => { block_receipts.remove(&h); }
}
}
cache_man.cache_usage.push_front(HashSet::new());
// TODO: handle block_hashes properly.
block_hashes.clear();
blocks.shrink_to_fit();
block_details.shrink_to_fit();
block_hashes.shrink_to_fit();
transaction_addresses.shrink_to_fit();
blocks_blooms.shrink_to_fit();
block_receipts.shrink_to_fit();
}
if self.cache_size().total() < self.max_cache_size.load(AtomicOrder::Relaxed) { break; }
}
// TODO: m_lastCollection = chrono::system_clock::now();
}
}
#[cfg(test)]
mod tests {
#![cfg_attr(feature="dev", allow(similar_names))]
use std::str::FromStr;
use rustc_serialize::hex::FromHex;
use util::hash::*;
use util::sha3::Hashable;
use blockchain::{BlockProvider, BlockChain, Config, ImportRoute};
use tests::helpers::*;
use devtools::*;
use blockchain::generator::{ChainGenerator, ChainIterator, BlockFinalizer};
use views::BlockView;
#[test]
fn basic_blockchain_insert() {
let mut canon_chain = ChainGenerator::default();
let mut finalizer = BlockFinalizer::default();
let genesis = canon_chain.generate(&mut finalizer).unwrap();
let first = canon_chain.generate(&mut finalizer).unwrap();
let genesis_hash = BlockView::new(&genesis).header_view().sha3();
let first_hash = BlockView::new(&first).header_view().sha3();
let temp = RandomTempPath::new();
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
assert_eq!(bc.genesis_hash(), genesis_hash.clone());
assert_eq!(bc.best_block_number(), 0);
assert_eq!(bc.best_block_hash(), genesis_hash.clone());
assert_eq!(bc.block_hash(0), Some(genesis_hash.clone()));
assert_eq!(bc.block_hash(1), None);
assert_eq!(bc.block_details(&genesis_hash).unwrap().children, vec![]);
bc.insert_block(&first, vec![]);
assert_eq!(bc.block_hash(0), Some(genesis_hash.clone()));
assert_eq!(bc.best_block_number(), 1);
assert_eq!(bc.best_block_hash(), first_hash.clone());
assert_eq!(bc.block_hash(1), Some(first_hash.clone()));
assert_eq!(bc.block_details(&first_hash).unwrap().parent, genesis_hash.clone());
assert_eq!(bc.block_details(&genesis_hash).unwrap().children, vec![first_hash.clone()]);
assert_eq!(bc.block_hash(2), None);
}
#[test]
fn check_ancestry_iter() {
let mut canon_chain = ChainGenerator::default();
let mut finalizer = BlockFinalizer::default();
let genesis = canon_chain.generate(&mut finalizer).unwrap();
let genesis_hash = BlockView::new(&genesis).header_view().sha3();
let temp = RandomTempPath::new();
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
let mut block_hashes = vec![genesis_hash.clone()];
for _ in 0..10 {
let block = canon_chain.generate(&mut finalizer).unwrap();
block_hashes.push(BlockView::new(&block).header_view().sha3());
bc.insert_block(&block, vec![]);
}
block_hashes.reverse();
assert_eq!(bc.ancestry_iter(block_hashes[0].clone()).unwrap().collect::<Vec<_>>(), block_hashes)
}
#[test]
#[cfg_attr(feature="dev", allow(cyclomatic_complexity))]
fn test_find_uncles() {
let mut canon_chain = ChainGenerator::default();
let mut finalizer = BlockFinalizer::default();
let genesis = canon_chain.generate(&mut finalizer).unwrap();
let b1b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
let b1a = canon_chain.generate(&mut finalizer).unwrap();
let b2b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
let b2a = canon_chain.generate(&mut finalizer).unwrap();
let b3b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
let b3a = canon_chain.generate(&mut finalizer).unwrap();
let b4b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
let b4a = canon_chain.generate(&mut finalizer).unwrap();
let b5b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
let b5a = canon_chain.generate(&mut finalizer).unwrap();
let temp = RandomTempPath::new();
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
bc.insert_block(&b1a, vec![]);
bc.insert_block(&b1b, vec![]);
bc.insert_block(&b2a, vec![]);
bc.insert_block(&b2b, vec![]);
bc.insert_block(&b3a, vec![]);
bc.insert_block(&b3b, vec![]);
bc.insert_block(&b4a, vec![]);
bc.insert_block(&b4b, vec![]);
bc.insert_block(&b5a, vec![]);
bc.insert_block(&b5b, vec![]);
assert_eq!(
[&b4b, &b3b, &b2b].iter().map(|b| BlockView::new(b).header()).collect::<Vec<_>>(),
bc.find_uncle_headers(&BlockView::new(&b4a).header_view().sha3(), 3).unwrap()
);
// TODO: insert block that already includes one of them as an uncle to check it's not allowed.
}
#[test]
#[cfg_attr(feature="dev", allow(cyclomatic_complexity))]
fn test_small_fork() {
let mut canon_chain = ChainGenerator::default();
let mut finalizer = BlockFinalizer::default();
let genesis = canon_chain.generate(&mut finalizer).unwrap();
let b1 = canon_chain.generate(&mut finalizer).unwrap();
let b2 = canon_chain.generate(&mut finalizer).unwrap();
let b3b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
let b3a = canon_chain.generate(&mut finalizer).unwrap();
let genesis_hash = BlockView::new(&genesis).header_view().sha3();
let b1_hash= BlockView::new(&b1).header_view().sha3();
let b2_hash= BlockView::new(&b2).header_view().sha3();
let b3a_hash= BlockView::new(&b3a).header_view().sha3();
let b3b_hash= BlockView::new(&b3b).header_view().sha3();
// b3a is a part of canon chain, whereas b3b is part of sidechain
let best_block_hash = b3a_hash.clone();
let temp = RandomTempPath::new();
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
let ir1 = bc.insert_block(&b1, vec![]);
let ir2 = bc.insert_block(&b2, vec![]);
let ir3b = bc.insert_block(&b3b, vec![]);
let ir3a = bc.insert_block(&b3a, vec![]);
assert_eq!(ir1, ImportRoute {
enacted: vec![b1_hash],
retracted: vec![],
omitted: vec![],
});
assert_eq!(ir2, ImportRoute {
enacted: vec![b2_hash],
retracted: vec![],
omitted: vec![],
});
assert_eq!(ir3b, ImportRoute {
enacted: vec![b3b_hash],
retracted: vec![],
omitted: vec![],
});
assert_eq!(ir3a, ImportRoute {
enacted: vec![b3a_hash],
retracted: vec![b3b_hash],
omitted: vec![],
});
assert_eq!(bc.best_block_hash(), best_block_hash);
assert_eq!(bc.block_number(&genesis_hash).unwrap(), 0);
assert_eq!(bc.block_number(&b1_hash).unwrap(), 1);
assert_eq!(bc.block_number(&b2_hash).unwrap(), 2);
assert_eq!(bc.block_number(&b3a_hash).unwrap(), 3);
assert_eq!(bc.block_number(&b3b_hash).unwrap(), 3);
assert_eq!(bc.block_hash(0).unwrap(), genesis_hash);
assert_eq!(bc.block_hash(1).unwrap(), b1_hash);
assert_eq!(bc.block_hash(2).unwrap(), b2_hash);
assert_eq!(bc.block_hash(3).unwrap(), b3a_hash);
// test trie route
let r0_1 = bc.tree_route(genesis_hash.clone(), b1_hash.clone());
assert_eq!(r0_1.ancestor, genesis_hash);
assert_eq!(r0_1.blocks, [b1_hash.clone()]);
assert_eq!(r0_1.index, 0);
let r0_2 = bc.tree_route(genesis_hash.clone(), b2_hash.clone());
assert_eq!(r0_2.ancestor, genesis_hash);
assert_eq!(r0_2.blocks, [b1_hash.clone(), b2_hash.clone()]);
assert_eq!(r0_2.index, 0);
let r1_3a = bc.tree_route(b1_hash.clone(), b3a_hash.clone());
assert_eq!(r1_3a.ancestor, b1_hash);
assert_eq!(r1_3a.blocks, [b2_hash.clone(), b3a_hash.clone()]);
assert_eq!(r1_3a.index, 0);
let r1_3b = bc.tree_route(b1_hash.clone(), b3b_hash.clone());
assert_eq!(r1_3b.ancestor, b1_hash);
assert_eq!(r1_3b.blocks, [b2_hash.clone(), b3b_hash.clone()]);
assert_eq!(r1_3b.index, 0);
let r3a_3b = bc.tree_route(b3a_hash.clone(), b3b_hash.clone());
assert_eq!(r3a_3b.ancestor, b2_hash);
assert_eq!(r3a_3b.blocks, [b3a_hash.clone(), b3b_hash.clone()]);
assert_eq!(r3a_3b.index, 1);
let r1_0 = bc.tree_route(b1_hash.clone(), genesis_hash.clone());
assert_eq!(r1_0.ancestor, genesis_hash);
assert_eq!(r1_0.blocks, [b1_hash.clone()]);
assert_eq!(r1_0.index, 1);
let r2_0 = bc.tree_route(b2_hash.clone(), genesis_hash.clone());
assert_eq!(r2_0.ancestor, genesis_hash);
assert_eq!(r2_0.blocks, [b2_hash.clone(), b1_hash.clone()]);
assert_eq!(r2_0.index, 2);
let r3a_1 = bc.tree_route(b3a_hash.clone(), b1_hash.clone());
assert_eq!(r3a_1.ancestor, b1_hash);
assert_eq!(r3a_1.blocks, [b3a_hash.clone(), b2_hash.clone()]);
assert_eq!(r3a_1.index, 2);
let r3b_1 = bc.tree_route(b3b_hash.clone(), b1_hash.clone());
assert_eq!(r3b_1.ancestor, b1_hash);
assert_eq!(r3b_1.blocks, [b3b_hash.clone(), b2_hash.clone()]);
assert_eq!(r3b_1.index, 2);
let r3b_3a = bc.tree_route(b3b_hash.clone(), b3a_hash.clone());
assert_eq!(r3b_3a.ancestor, b2_hash);
assert_eq!(r3b_3a.blocks, [b3b_hash.clone(), b3a_hash.clone()]);
assert_eq!(r3b_3a.index, 1);
}
#[test]
fn test_reopen_blockchain_db() {
let mut canon_chain = ChainGenerator::default();
let mut finalizer = BlockFinalizer::default();
let genesis = canon_chain.generate(&mut finalizer).unwrap();
let first = canon_chain.generate(&mut finalizer).unwrap();
let genesis_hash = BlockView::new(&genesis).header_view().sha3();
let first_hash = BlockView::new(&first).header_view().sha3();
let temp = RandomTempPath::new();
{
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
assert_eq!(bc.best_block_hash(), genesis_hash);
bc.insert_block(&first, vec![]);
assert_eq!(bc.best_block_hash(), first_hash);
}
{
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
assert_eq!(bc.best_block_hash(), first_hash);
}
}
#[test]
fn can_contain_arbitrary_block_sequence() {
let bc_result = generate_dummy_blockchain(50);
let bc = bc_result.reference();
assert_eq!(bc.best_block_number(), 49);
}
#[test]
fn can_collect_garbage() {
let bc_result = generate_dummy_blockchain(3000);
let bc = bc_result.reference();
assert_eq!(bc.best_block_number(), 2999);
let best_hash = bc.best_block_hash();
let mut block_header = bc.block_header(&best_hash);
while !block_header.is_none() {
block_header = bc.block_header(&block_header.unwrap().parent_hash);
}
assert!(bc.cache_size().blocks > 1024 * 1024);
for _ in 0..2 {
bc.collect_garbage();
}
assert!(bc.cache_size().blocks < 1024 * 1024);
}
#[test]
fn can_contain_arbitrary_block_sequence_with_extra() {
let bc_result = generate_dummy_blockchain_with_extra(25);
let bc = bc_result.reference();
assert_eq!(bc.best_block_number(), 24);
}
#[test]
fn can_contain_only_genesis_block() {
let bc_result = generate_dummy_empty_blockchain();
let bc = bc_result.reference();
assert_eq!(bc.best_block_number(), 0);
}
#[test]
fn find_transaction_by_hash() {
let genesis = "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".from_hex().unwrap();
let b1 = "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".from_hex().unwrap();
let b1_hash = H256::from_str("f53f268d23a71e85c7d6d83a9504298712b84c1a2ba220441c86eeda0bf0b6e3").unwrap();
let temp = RandomTempPath::new();
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
bc.insert_block(&b1, vec![]);
let transactions = bc.transactions(&b1_hash).unwrap();
assert_eq!(transactions.len(), 7);
for t in transactions {
assert_eq!(bc.transaction(&bc.transaction_address(&t.hash()).unwrap()).unwrap(), t);
}
}
#[test]
fn test_bloom_filter_simple() {
// TODO: From here
let bloom_b1 = H2048::from_str("00000020000000000000000000000000000000000000000002000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000040000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008000400000000000000000000002000").unwrap();
let bloom_b2 = H2048::from_str("00000000000000000000000000000000000000000000020000001000000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000008000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
let bloom_ba = H2048::from_str("00000000000000000000000000000000000000000000020000000800000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000008000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
let mut canon_chain = ChainGenerator::default();
let mut finalizer = BlockFinalizer::default();
let genesis = canon_chain.generate(&mut finalizer).unwrap();
let mut fork = canon_chain.fork(1);
let mut fork_finalizer = finalizer.fork();
let b1 = fork.with_bloom(bloom_b1.clone()).generate(&mut fork_finalizer).unwrap();
let b2 = fork.with_bloom(bloom_b2.clone()).generate(&mut fork_finalizer).unwrap();
let b3 = fork.with_bloom(bloom_ba.clone()).generate(&mut fork_finalizer).unwrap();
let b1a = canon_chain.with_bloom(bloom_ba.clone()).generate(&mut finalizer).unwrap();
let b2a = canon_chain.with_bloom(bloom_ba.clone()).generate(&mut finalizer).unwrap();
let temp = RandomTempPath::new();
let bc = BlockChain::new(Config::default(), &genesis, temp.as_path());
let blocks_b1 = bc.blocks_with_bloom(&bloom_b1, 0, 5);
let blocks_b2 = bc.blocks_with_bloom(&bloom_b2, 0, 5);
assert_eq!(blocks_b1, vec![]);
assert_eq!(blocks_b2, vec![]);
bc.insert_block(&b1, vec![]);
let blocks_b1 = bc.blocks_with_bloom(&bloom_b1, 0, 5);
let blocks_b2 = bc.blocks_with_bloom(&bloom_b2, 0, 5);
assert_eq!(blocks_b1, vec![1]);
assert_eq!(blocks_b2, vec![]);
bc.insert_block(&b2, vec![]);
let blocks_b1 = bc.blocks_with_bloom(&bloom_b1, 0, 5);
let blocks_b2 = bc.blocks_with_bloom(&bloom_b2, 0, 5);
assert_eq!(blocks_b1, vec![1]);
assert_eq!(blocks_b2, vec![2]);
// hasn't been forked yet
bc.insert_block(&b1a, vec![]);
let blocks_b1 = bc.blocks_with_bloom(&bloom_b1, 0, 5);
let blocks_b2 = bc.blocks_with_bloom(&bloom_b2, 0, 5);
let blocks_ba = bc.blocks_with_bloom(&bloom_ba, 0, 5);
assert_eq!(blocks_b1, vec![1]);
assert_eq!(blocks_b2, vec![2]);
assert_eq!(blocks_ba, vec![]);
// fork has happend
bc.insert_block(&b2a, vec![]);
let blocks_b1 = bc.blocks_with_bloom(&bloom_b1, 0, 5);
let blocks_b2 = bc.blocks_with_bloom(&bloom_b2, 0, 5);
let blocks_ba = bc.blocks_with_bloom(&bloom_ba, 0, 5);
assert_eq!(blocks_b1, vec![]);
assert_eq!(blocks_b2, vec![]);
assert_eq!(blocks_ba, vec![1, 2]);
// fork back
bc.insert_block(&b3, vec![]);
let blocks_b1 = bc.blocks_with_bloom(&bloom_b1, 0, 5);
let blocks_b2 = bc.blocks_with_bloom(&bloom_b2, 0, 5);
let blocks_ba = bc.blocks_with_bloom(&bloom_ba, 0, 5);
assert_eq!(blocks_b1, vec![1]);
assert_eq!(blocks_b2, vec![2]);
assert_eq!(blocks_ba, vec![3]);
}
}