Fine grained snapshot chunking

Cargo.lock

@@ -414,6 +414,7 @@ dependencies = [
  "evmjit 1.7.0",
  "hardware-wallet 1.7.0",
  "hyper 0.10.0-a.0 (git+https://github.com/paritytech/hyper)",
+ "itertools 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "linked-hash-map 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",

ethcore/Cargo.toml

@@ -27,6 +27,7 @@ byteorder = "1.0"
 transient-hashmap = "0.4"
 linked-hash-map = "0.3.0"
 lru-cache = "0.1.0"
+itertools = "0.5"
 ethabi = "1.0.0"
 evmjit = { path = "../evmjit", optional = true }
 clippy = { version = "0.0.103", optional = true}

ethcore/src/lib.rs

@@ -108,6 +108,7 @@ extern crate hardware_wallet;
 extern crate stats;
 extern crate ethcore_logger;
 extern crate num;
+extern crate itertools;
 
 #[macro_use]
 extern crate log;

ethcore/src/snapshot/account.rs

@@ -23,6 +23,7 @@ use snapshot::Error;
 use util::{U256, H256, Bytes, HashDB, SHA3_EMPTY, SHA3_NULL_RLP};
 use util::trie::{TrieDB, Trie};
 use rlp::{RlpStream, UntrustedRlp};
+use itertools::Itertools;
 
 use std::collections::HashSet;
 
@@ -62,23 +63,20 @@ impl CodeState {
 
 // walk the account's storage trie, returning an RLP item containing the
 // account properties and the storage.
-pub fn to_fat_rlp(acc: &BasicAccount, acct_db: &AccountDB, used_code: &mut HashSet<H256>) -> Result<Bytes, Error> {
+pub fn to_fat_rlps(acc: &BasicAccount, acct_db: &AccountDB, used_code: &mut HashSet<H256>, preferred_size: usize) -> Result<Vec<Bytes>, Error> {
+	const AVERAGE_BYTES_PER_STORAGE_ENTRY: usize = 47;
 	if acc == &ACC_EMPTY {
-		return Ok(::rlp::NULL_RLP.to_vec());
+		return Ok(vec![::rlp::NULL_RLP.to_vec()]);
 	}
 
 	let db = TrieDB::new(acct_db, &acc.storage_root)?;
 
-	let mut pairs = Vec::new();
+	let pair_chunks: Vec<Vec<_>> = db.iter()?.chunks(preferred_size / AVERAGE_BYTES_PER_STORAGE_ENTRY).into_iter().map(|chunk| chunk.collect()).collect();
-
+	pair_chunks.into_iter().pad_using(1, |_| Vec::new(), ).map(|pairs| {
-	for item in db.iter()? {
-		let (k, v) = item?;
-		pairs.push((k, v));
-	}
-
 		let mut stream = RlpStream::new_list(pairs.len());
 
-	for (k, v) in pairs {
+		for r in pairs {
+			let (k, v) = r?;
 			stream.begin_list(2).append(&k).append(&&*v);
 		}
 
@@ -107,8 +105,8 @@ pub fn to_fat_rlp(acc: &BasicAccount, acct_db: &AccountDB, used_code: &mut HashS
 		}
 
 		account_stream.append_raw(&pairs_rlp, 1);
-
 		Ok(account_stream.out())
+	}).collect()
 }
 
 // decode a fat rlp, and rebuild the storage trie as we go.
@@ -117,6 +115,7 @@ pub fn to_fat_rlp(acc: &BasicAccount, acct_db: &AccountDB, used_code: &mut HashS
 pub fn from_fat_rlp(
 	acct_db: &mut AccountDBMut,
 	rlp: UntrustedRlp,
+	mut storage_root: H256,
 ) -> Result<(BasicAccount, Option<Bytes>), Error> {
 	use util::{TrieDBMut, TrieMut};
 
@@ -148,10 +147,12 @@ pub fn from_fat_rlp(
 		}
 	};
 
-	let mut storage_root = H256::zero();
-
 	{
-		let mut storage_trie = TrieDBMut::new(acct_db, &mut storage_root);
+		let mut storage_trie = if storage_root.is_zero() {
+			TrieDBMut::new(acct_db, &mut storage_root)
+		} else {
+			TrieDBMut::from_existing(acct_db, &mut storage_root)?
+		};
 		let pairs = rlp.at(4)?;
 		for pair_rlp in pairs.iter() {
 			let k: Bytes  = pair_rlp.val_at(0)?;
@@ -184,7 +185,7 @@ mod tests {
 
 	use std::collections::HashSet;
 
-	use super::{ACC_EMPTY, to_fat_rlp, from_fat_rlp};
+	use super::{ACC_EMPTY, to_fat_rlps, from_fat_rlp};
 
 	#[test]
 	fn encoding_basic() {
@@ -201,9 +202,9 @@ mod tests {
 		let thin_rlp = ::rlp::encode(&account);
 		assert_eq!(::rlp::decode::<BasicAccount>(&thin_rlp), account);
 
-		let fat_rlp = to_fat_rlp(&account, &AccountDB::new(db.as_hashdb(), &addr), &mut Default::default()).unwrap();
+		let fat_rlps = to_fat_rlps(&account, &AccountDB::new(db.as_hashdb(), &addr), &mut Default::default(), usize::max_value()).unwrap();
-		let fat_rlp = UntrustedRlp::new(&fat_rlp);
+		let fat_rlp = UntrustedRlp::new(&fat_rlps[0]);
-		assert_eq!(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr), fat_rlp).unwrap().0, account);
+		assert_eq!(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr), fat_rlp, H256::zero()).unwrap().0, account);
 	}
 
 	#[test]
@@ -226,9 +227,40 @@ mod tests {
 		let thin_rlp = ::rlp::encode(&account);
 		assert_eq!(::rlp::decode::<BasicAccount>(&thin_rlp), account);
 
-		let fat_rlp = to_fat_rlp(&account, &AccountDB::new(db.as_hashdb(), &addr), &mut Default::default()).unwrap();
+		let fat_rlp = to_fat_rlps(&account, &AccountDB::new(db.as_hashdb(), &addr), &mut Default::default(), usize::max_value()).unwrap();
-		let fat_rlp = UntrustedRlp::new(&fat_rlp);
+		let fat_rlp = UntrustedRlp::new(&fat_rlp[0]);
-		assert_eq!(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr), fat_rlp).unwrap().0, account);
+		assert_eq!(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr), fat_rlp, H256::zero()).unwrap().0, account);
+	}
+
+	#[test]
+	fn encoding_storage_split() {
+		let mut db = get_temp_state_db();
+		let addr = Address::random();
+
+		let account = {
+			let acct_db = AccountDBMut::new(db.as_hashdb_mut(), &addr);
+			let mut root = SHA3_NULL_RLP;
+			fill_storage(acct_db, &mut root, &mut H256::zero());
+			BasicAccount {
+				nonce: 25.into(),
+				balance: 987654321.into(),
+				storage_root: root,
+				code_hash: SHA3_EMPTY,
+			}
+		};
+
+		let thin_rlp = ::rlp::encode(&account);
+		assert_eq!(::rlp::decode::<BasicAccount>(&thin_rlp), account);
+
+		let fat_rlps = to_fat_rlps(&account, &AccountDB::new(db.as_hashdb(), &addr), &mut Default::default(), 1000).unwrap();
+		let mut root = SHA3_NULL_RLP;
+		let mut restored_account = None;
+		for rlp in fat_rlps {
+			let fat_rlp = UntrustedRlp::new(&rlp);
+			restored_account = Some(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr), fat_rlp, root).unwrap().0);
+			root = restored_account.as_ref().unwrap().storage_root.clone();
+		}
+		assert_eq!(restored_account, Some(account));
 	}
 
 	#[test]
@@ -264,18 +296,18 @@ mod tests {
 
 		let mut used_code = HashSet::new();
 
-		let fat_rlp1 = to_fat_rlp(&account1, &AccountDB::new(db.as_hashdb(), &addr1), &mut used_code).unwrap();
+		let fat_rlp1 = to_fat_rlps(&account1, &AccountDB::new(db.as_hashdb(), &addr1), &mut used_code, usize::max_value()).unwrap();
-		let fat_rlp2 = to_fat_rlp(&account2, &AccountDB::new(db.as_hashdb(), &addr2), &mut used_code).unwrap();
+		let fat_rlp2 = to_fat_rlps(&account2, &AccountDB::new(db.as_hashdb(), &addr2), &mut used_code, usize::max_value()).unwrap();
 		assert_eq!(used_code.len(), 1);
 
-		let fat_rlp1 = UntrustedRlp::new(&fat_rlp1);
+		let fat_rlp1 = UntrustedRlp::new(&fat_rlp1[0]);
-		let fat_rlp2 = UntrustedRlp::new(&fat_rlp2);
+		let fat_rlp2 = UntrustedRlp::new(&fat_rlp2[0]);
 
-		let (acc, maybe_code) = from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr2), fat_rlp2).unwrap();
+		let (acc, maybe_code) = from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr2), fat_rlp2, H256::zero()).unwrap();
 		assert!(maybe_code.is_none());
 		assert_eq!(acc, account2);
 
-		let (acc, maybe_code) = from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr1), fat_rlp1).unwrap();
+		let (acc, maybe_code) = from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &addr1), fat_rlp1, H256::zero()).unwrap();
 		assert_eq!(maybe_code, Some(b"this is definitely code".to_vec()));
 		assert_eq!(acc, account1);
 	}
@@ -285,7 +317,7 @@ mod tests {
 		let mut db = get_temp_state_db();
 		let mut used_code = HashSet::new();
 
-		assert_eq!(to_fat_rlp(&ACC_EMPTY, &AccountDB::new(db.as_hashdb(), &Address::default()), &mut used_code).unwrap(), ::rlp::NULL_RLP.to_vec());
+		assert_eq!(to_fat_rlps(&ACC_EMPTY, &AccountDB::new(db.as_hashdb(), &Address::default()), &mut used_code, usize::max_value()).unwrap(), vec![::rlp::NULL_RLP.to_vec()]);
-		assert_eq!(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &Address::default()), UntrustedRlp::new(&::rlp::NULL_RLP)).unwrap(), (ACC_EMPTY, None));
+		assert_eq!(from_fat_rlp(&mut AccountDBMut::new(db.as_hashdb_mut(), &Address::default()), UntrustedRlp::new(&::rlp::NULL_RLP), H256::zero()).unwrap(), (ACC_EMPTY, None));
 	}
 }

ethcore/src/snapshot/error.rs

@@ -53,6 +53,8 @@ pub enum Error {
 	Decoder(DecoderError),
 	/// Io error.
 	Io(::std::io::Error),
+	/// Snapshot version is not supported.
+	VersionNotSupported(u64),
 }
 
 impl fmt::Display for Error {
@@ -73,6 +75,7 @@ impl fmt::Display for Error {
 			Error::Io(ref err) => err.fmt(f),
 			Error::Decoder(ref err) => err.fmt(f),
 			Error::Trie(ref err) => err.fmt(f),
+			Error::VersionNotSupported(ref ver) => write!(f, "Snapshot version {} is not supprted.", ver),
 		}
 	}
 }

ethcore/src/snapshot/io.rs

@@ -31,6 +31,8 @@ use rlp::{self, Encodable, RlpStream, UntrustedRlp};
 
 use super::ManifestData;
 
+const SNAPSHOT_VERSION: u64 = 2;
+
 /// Something which can write snapshots.
 /// Writing the same chunk multiple times will lead to implementation-defined
 /// behavior, and is not advised.
@@ -118,8 +120,9 @@ impl SnapshotWriter for PackedWriter {
 	fn finish(mut self, manifest: ManifestData) -> io::Result<()> {
 		// we ignore the hashes fields of the manifest under the assumption that
 		// they are consistent with ours.
-		let mut stream = RlpStream::new_list(5);
+		let mut stream = RlpStream::new_list(6);
 		stream
+			.append(&SNAPSHOT_VERSION)
 			.append_list(&self.state_hashes)
 			.append_list(&self.block_hashes)
 			.append(&manifest.state_root)
@@ -221,7 +224,7 @@ impl PackedReader {
 	/// Create a new `PackedReader` for the file at the given path.
 	/// This will fail if any io errors are encountered or the file
 	/// is not a valid packed snapshot.
-	pub fn new(path: &Path) -> Result<Option<Self>, ::error::Error> {
+	pub fn new(path: &Path) -> Result<Option<Self>, ::snapshot::error::Error> {
 		let mut file = File::open(path)?;
 		let file_len = file.metadata()?.len();
 		if file_len < 8 {
@@ -255,15 +258,26 @@ impl PackedReader {
 
 		let rlp = UntrustedRlp::new(&manifest_buf);
 
-		let state: Vec<ChunkInfo> = rlp.list_at(0)?;
+		let (start, version) = if rlp.item_count()? == 5 {
-		let blocks: Vec<ChunkInfo> = rlp.list_at(1)?;
+			(0, 1)
+		} else {
+			(1, rlp.val_at(0)?)
+		};
+
+		if version > SNAPSHOT_VERSION {
+			return Err(::snapshot::error::Error::VersionNotSupported(version));
+		}
+
+		let state: Vec<ChunkInfo> = rlp.list_at(0 + start)?;
+		let blocks: Vec<ChunkInfo> = rlp.list_at(1 + start)?;
 
 		let manifest = ManifestData {
+			version: version,
 			state_hashes: state.iter().map(|c| c.0).collect(),
 			block_hashes: blocks.iter().map(|c| c.0).collect(),
-			state_root: rlp.val_at(2)?,
+			state_root: rlp.val_at(2 + start)?,
-			block_number: rlp.val_at(3)?,
+			block_number: rlp.val_at(3 + start)?,
-			block_hash: rlp.val_at(4)?,
+			block_hash: rlp.val_at(4 + start)?,
 		};
 
 		Ok(Some(PackedReader {
@@ -346,7 +360,7 @@ mod tests {
 	use util::sha3::Hashable;
 
 	use snapshot::ManifestData;
-	use super::{SnapshotWriter, SnapshotReader, PackedWriter, PackedReader, LooseWriter, LooseReader};
+	use super::{SnapshotWriter, SnapshotReader, PackedWriter, PackedReader, LooseWriter, LooseReader, SNAPSHOT_VERSION};
 
 	const STATE_CHUNKS: &'static [&'static [u8]] = &[b"dog", b"cat", b"hello world", b"hi", b"notarealchunk"];
 	const BLOCK_CHUNKS: &'static [&'static [u8]] = &[b"hello!", b"goodbye!", b"abcdefg", b"hijklmnop", b"qrstuvwxy", b"and", b"z"];
@@ -372,6 +386,7 @@ mod tests {
 		}
 
 		let manifest = ManifestData {
+			version: SNAPSHOT_VERSION,
 			state_hashes: state_hashes,
 			block_hashes: block_hashes,
 			state_root: b"notarealroot".sha3(),
@@ -410,6 +425,7 @@ mod tests {
 		}
 
 		let manifest = ManifestData {
+			version: SNAPSHOT_VERSION,
 			state_hashes: state_hashes,
 			block_hashes: block_hashes,
 			state_root: b"notarealroot".sha3(),

ethcore/src/snapshot/mod.rs

@@ -56,6 +56,7 @@ pub use self::traits::SnapshotService;
 pub use self::watcher::Watcher;
 pub use types::snapshot_manifest::ManifestData;
 pub use types::restoration_status::RestorationStatus;
+pub use types::basic_account::BasicAccount;
 
 pub mod io;
 pub mod service;
@@ -147,6 +148,7 @@ pub fn take_snapshot<W: SnapshotWriter + Send>(
 	info!("produced {} state chunks and {} block chunks.", state_hashes.len(), block_hashes.len());
 
 	let manifest_data = ManifestData {
+		version: 2,
 		state_hashes: state_hashes,
 		block_hashes: block_hashes,
 		state_root: *state_root,
@@ -300,14 +302,14 @@ impl<'a> StateChunker<'a> {
 	//
 	// If the buffer is greater than the desired chunk size,
 	// this will write out the data to disk.
-	fn push(&mut self, account_hash: Bytes, data: Bytes) -> Result<(), Error> {
+	fn push(&mut self, account_hash: Bytes, data: Bytes, force_chunk: bool) -> Result<(), Error> {
 		let pair = {
 			let mut stream = RlpStream::new_list(2);
 			stream.append(&account_hash).append_raw(&data, 1);
 			stream.out()
 		};
 
-		if self.cur_size + pair.len() >= PREFERRED_CHUNK_SIZE {
+		if force_chunk || self.cur_size + pair.len() >= PREFERRED_CHUNK_SIZE {
 			self.write_chunk()?;
 		}
 
@@ -372,8 +374,10 @@ pub fn chunk_state<'a>(db: &HashDB, root: &H256, writer: &Mutex<SnapshotWriter +
 
 		let account_db = AccountDB::from_hash(db, account_key_hash);
 
-		let fat_rlp = account::to_fat_rlp(&account, &account_db, &mut used_code)?;
+		let fat_rlps = account::to_fat_rlps(&account, &account_db, &mut used_code, PREFERRED_CHUNK_SIZE)?;
-		chunker.push(account_key, fat_rlp)?;
+		for (i, fat_rlp) in fat_rlps.into_iter().enumerate() {
+			chunker.push(account_key.clone(), fat_rlp, i > 0)?;
+		}
 	}
 
 	if chunker.cur_size != 0 {
@@ -390,6 +394,7 @@ pub struct StateRebuilder {
 	known_code: HashMap<H256, H256>, // code hashes mapped to first account with this code.
 	missing_code: HashMap<H256, Vec<H256>>, // maps code hashes to lists of accounts missing that code.
 	bloom: Bloom,
+	known_storage_roots: HashMap<H256, H256>, // maps account hashes to last known storage root. Only filled for last account per chunk.
 }
 
 impl StateRebuilder {
@@ -401,6 +406,7 @@ impl StateRebuilder {
 			known_code: HashMap::new(),
 			missing_code: HashMap::new(),
 			bloom: StateDB::load_bloom(&*db),
+			known_storage_roots: HashMap::new(),
 		}
 	}
 
@@ -418,6 +424,7 @@ impl StateRebuilder {
 			rlp,
 			&mut pairs,
 			&self.known_code,
+			&mut self.known_storage_roots,
 			flag
 		)?;
 
@@ -496,10 +503,11 @@ fn rebuild_accounts(
 	account_fat_rlps: UntrustedRlp,
 	out_chunk: &mut [(H256, Bytes)],
 	known_code: &HashMap<H256, H256>,
+	known_storage_roots: &mut HashMap<H256, H256>,
 	abort_flag: &AtomicBool,
 ) -> Result<RebuiltStatus, ::error::Error> {
 	let mut status = RebuiltStatus::default();
-	for (account_rlp, out) in account_fat_rlps.into_iter().zip(out_chunk) {
+	for (account_rlp, out) in account_fat_rlps.into_iter().zip(out_chunk.iter_mut()) {
 		if !abort_flag.load(Ordering::SeqCst) { return Err(Error::RestorationAborted.into()) }
 
 		let hash: H256 = account_rlp.val_at(0)?;
@@ -510,7 +518,8 @@ fn rebuild_accounts(
 			// fill out the storage trie and code while decoding.
 			let (acc, maybe_code) = {
 				let mut acct_db = AccountDBMut::from_hash(db, hash);
-				account::from_fat_rlp(&mut acct_db, fat_rlp)?
+				let storage_root = known_storage_roots.get(&hash).cloned().unwrap_or(H256::zero());
+				account::from_fat_rlp(&mut acct_db, fat_rlp, storage_root)?
 			};
 
 			let code_hash = acc.code_hash.clone();
@@ -542,6 +551,12 @@ fn rebuild_accounts(
 
 		*out = (hash, thin_rlp);
 	}
+	if let Some(&(ref hash, ref rlp)) = out_chunk.iter().last() {
+		known_storage_roots.insert(*hash, ::rlp::decode::<BasicAccount>(rlp).storage_root);
+	}
+	if let Some(&(ref hash, ref rlp)) = out_chunk.iter().next() {
+		known_storage_roots.insert(*hash, ::rlp::decode::<BasicAccount>(rlp).storage_root);
+	}
 	Ok(status)
 }
 

ethcore/src/snapshot/service.rs

@@ -656,6 +656,7 @@ mod tests {
 		assert_eq!(service.status(), RestorationStatus::Inactive);
 
 		let manifest = ManifestData {
+			version: 2,
 			state_hashes: vec![],
 			block_hashes: vec![],
 			state_root: Default::default(),

ethcore/src/snapshot/tests/blocks.rs

@@ -63,6 +63,7 @@ fn chunk_and_restore(amount: u64) {
 	let writer = Mutex::new(PackedWriter::new(&snapshot_path).unwrap());
 	let block_hashes = chunk_blocks(&bc, best_hash, &writer, &Progress::default()).unwrap();
 	let manifest = ::snapshot::ManifestData {
+		version: 2,
 		state_hashes: Vec::new(),
 		block_hashes: block_hashes,
 		state_root: ::util::sha3::SHA3_NULL_RLP,
@@ -125,6 +126,7 @@ fn checks_flag() {
 	let chain = BlockChain::new(Default::default(), &genesis, db.clone());
 
 	let manifest = ::snapshot::ManifestData {
+		version: 2,
 		state_hashes: Vec::new(),
 		block_hashes: Vec::new(),
 		state_root: ::util::sha3::SHA3_NULL_RLP,

ethcore/src/snapshot/tests/mod.rs

@@ -27,6 +27,7 @@ use super::ManifestData;
 #[test]
 fn manifest_rlp() {
 	let manifest = ManifestData {
+		version: 2,
 		block_hashes: Vec::new(),
 		state_hashes: Vec::new(),
 		block_number: 1234567,

ethcore/src/snapshot/tests/service.rs

@@ -122,6 +122,7 @@ fn guards_delete_folders() {
 	path.push("restoration");
 
 	let manifest = ManifestData {
+		version: 2,
 		state_hashes: vec![],
 		block_hashes: vec![],
 		block_number: 0,

ethcore/src/snapshot/tests/state.rs

@@ -58,6 +58,7 @@ fn snap_and_restore() {
 	let state_hashes = chunk_state(&old_db, &state_root, &writer, &Progress::default()).unwrap();
 
 	writer.into_inner().finish(::snapshot::ManifestData {
+		version: 2,
 		state_hashes: state_hashes,
 		block_hashes: Vec::new(),
 		state_root: state_root,
@@ -121,10 +122,10 @@ fn get_code_from_prev_chunk() {
 		let mut db = MemoryDB::new();
 		AccountDBMut::from_hash(&mut db, hash).insert(&code[..]);
 
-		let fat_rlp = account::to_fat_rlp(&acc, &AccountDB::from_hash(&db, hash), &mut used_code).unwrap();
+		let fat_rlp = account::to_fat_rlps(&acc, &AccountDB::from_hash(&db, hash), &mut used_code, usize::max_value()).unwrap();
 
 		let mut stream = RlpStream::new_list(1);
-		stream.begin_list(2).append(&hash).append_raw(&fat_rlp, 1);
+		stream.begin_list(2).append(&hash).append_raw(&fat_rlp[0], 1);
 		stream.out()
 	};
 
@@ -170,6 +171,7 @@ fn checks_flag() {
 	let state_hashes = chunk_state(&old_db, &state_root, &writer, &Progress::default()).unwrap();
 
 	writer.into_inner().finish(::snapshot::ManifestData {
+		version: 2,
 		state_hashes: state_hashes,
 		block_hashes: Vec::new(),
 		state_root: state_root,

ethcore/src/types/snapshot_manifest.rs

@@ -24,6 +24,8 @@ use util::Bytes;
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "ipc", binary)]
 pub struct ManifestData {
+	/// Snapshot format version.
+	pub version: u64,
 	/// List of state chunk hashes.
 	pub state_hashes: Vec<H256>,
 	/// List of block chunk hashes.
@@ -39,7 +41,8 @@ pub struct ManifestData {
 impl ManifestData {
 	/// Encode the manifest data to rlp.
 	pub fn into_rlp(self) -> Bytes {
-		let mut stream = RlpStream::new_list(5);
+		let mut stream = RlpStream::new_list(6);
+		stream.append(&self.version);
 		stream.append_list(&self.state_hashes);
 		stream.append_list(&self.block_hashes);
 		stream.append(&self.state_root);
@@ -52,14 +55,20 @@ impl ManifestData {
 	/// Try to restore manifest data from raw bytes, interpreted as RLP.
 	pub fn from_rlp(raw: &[u8]) -> Result<Self, DecoderError> {
 		let decoder = UntrustedRlp::new(raw);
+		let (start, version) = if decoder.item_count()? == 5 {
+			(0, 1)
+		} else {
+			(1, decoder.val_at(0)?)
+		};
 
-		let state_hashes: Vec<H256> = decoder.list_at(0)?;
+		let state_hashes: Vec<H256> = decoder.list_at(start + 0)?;
-		let block_hashes: Vec<H256> = decoder.list_at(1)?;
+		let block_hashes: Vec<H256> = decoder.list_at(start + 1)?;
-		let state_root: H256 = decoder.val_at(2)?;
+		let state_root: H256 = decoder.val_at(start + 2)?;
-		let block_number: u64 = decoder.val_at(3)?;
+		let block_number: u64 = decoder.val_at(start + 3)?;
-		let block_hash: H256 = decoder.val_at(4)?;
+		let block_hash: H256 = decoder.val_at(start + 4)?;
 
 		Ok(ManifestData {
+			version: version,
 			state_hashes: state_hashes,
 			block_hashes: block_hashes,
 			state_root: state_root,

sync/src/chain.rs

@@ -158,6 +158,8 @@ pub const SNAPSHOT_SYNC_PACKET_COUNT: u8 = 0x16;
 
 const MAX_SNAPSHOT_CHUNKS_DOWNLOAD_AHEAD: usize = 3;
 
+const MIN_SUPPORTED_SNAPSHOT_MANIFEST_VERSION: u64 = 1;
+
 const WAIT_PEERS_TIMEOUT_SEC: u64 = 5;
 const STATUS_TIMEOUT_SEC: u64 = 5;
 const HEADERS_TIMEOUT_SEC: u64 = 15;
@@ -1028,12 +1030,18 @@ impl ChainSync {
 		let manifest = match ManifestData::from_rlp(manifest_rlp.as_raw()) {
 			Err(e) => {
 				trace!(target: "sync", "{}: Ignored bad manifest: {:?}", peer_id, e);
-				io.disconnect_peer(peer_id);
+				io.disable_peer(peer_id);
 				self.continue_sync(io);
 				return Ok(());
 			}
 			Ok(manifest) => manifest,
 		};
+		if manifest.version < MIN_SUPPORTED_SNAPSHOT_MANIFEST_VERSION {
+			trace!(target: "sync", "{}: Snapshot manifest version too low: {}", peer_id, manifest.version);
+			io.disable_peer(peer_id);
+			self.continue_sync(io);
+			return Ok(());
+		}
 		self.snapshot.reset_to(&manifest, &manifest_rlp.as_raw().sha3());
 		io.snapshot_service().begin_restore(manifest);
 		self.state = SyncState::SnapshotData;

util/src/journaldb/overlayrecentdb.rs

@@ -380,10 +380,7 @@ impl JournalDB for OverlayRecentDB {
 
 			match rc {
 				0 => {}
-				1 => {
+				_ if rc > 0 => {
-					if cfg!(debug_assertions) && self.backing.get(self.column, &key)?.is_some() {
-						return Err(BaseDataError::AlreadyExists(key).into());
-					}
 					batch.put(self.column, &key, &value)
 				}
 				-1 => {
@@ -392,7 +389,7 @@ impl JournalDB for OverlayRecentDB {
 					}
 					batch.delete(self.column, &key)
 				}
-				_ => panic!("Attempted to inject invalid state."),
+				_ => panic!("Attempted to inject invalid state ({})", rc),
 			}
 		}