More snapshot fixes and optimizations

ethcore/res/ethereum/frontier.json

@@ -164,8 +164,7 @@
 		"enode://a979fb575495b8d6db44f750317d0f4622bf4c2aa3365d6af7c284339968eef29b69ad0dce72a4d8db5ebb4968de0e3bec910127f134779fbcb0cb6d3331163c@52.16.188.185:30303",
 		"enode://de471bccee3d042261d52e9bff31458daecc406142b401d4cd848f677479f73104b9fdeb090af9583d3391b7f10cb2ba9e26865dd5fca4fcdc0fb1e3b723c786@54.94.239.50:30303",
 		"enode://1118980bf48b0a3640bdba04e0fe78b1add18e1cd99bf22d53daac1fd9972ad650df52176e7c7d89d1114cfef2bc23a2959aa54998a46afcf7d91809f0855082@52.74.57.123:30303",
-		"enode://4cd540b2c3292e17cff39922e864094bf8b0741fcc8c5dcea14957e389d7944c70278d872902e3d0345927f621547efa659013c400865485ab4bfa0c6596936f@zero.parity.io:30303",
-		"enode://cc92c4c40d612a10c877ca023ef0496c843fbc92b6c6c0d55ce0b863d51d821c4bd70daebb54324a6086374e6dc05708fed39862b275f169cb678e655da9d07d@136.243.154.246:30303"
+		"enode://4cd540b2c3292e17cff39922e864094bf8b0741fcc8c5dcea14957e389d7944c70278d872902e3d0345927f621547efa659013c400865485ab4bfa0c6596936f@138.201.144.135:30303"
 	],
 	"accounts": {
 		"0000000000000000000000000000000000000001": { "builtin": { "name": "ecrecover", "pricing": { "linear": { "base": 3000, "word": 0 } } } },

ethcore/src/snapshot/mod.rs

@@ -30,7 +30,6 @@ use ids::BlockID;
 use views::BlockView;
 
 use util::{Bytes, Hashable, HashDB, snappy, U256, Uint};
-use util::memorydb::MemoryDB;
 use util::Mutex;
 use util::hash::{FixedHash, H256};
 use util::journaldb::{self, Algorithm, JournalDB};
@@ -47,7 +46,7 @@ use self::io::SnapshotWriter;
 use super::state_db::StateDB;
 use super::state::Account as StateAccount;
 
-use crossbeam::{scope, ScopedJoinHandle};
+use crossbeam::scope;
 use rand::{Rng, OsRng};
 
 pub use self::error::Error;
@@ -421,38 +420,14 @@ impl StateRebuilder {
 		// new code contained within this chunk.
 		let mut chunk_code = HashMap::new();
 
-		// build account tries in parallel.
-		// Todo [rob] keep a thread pool around so we don't do this per-chunk.
-		try!(scope(|scope| {
-			let mut handles = Vec::new();
-			for (account_chunk, out_pairs_chunk) in account_fat_rlps.chunks(chunk_size).zip(pairs.chunks_mut(chunk_size)) {
-				let code_map = &self.code_map;
-				let handle: ScopedJoinHandle<Result<_, ::error::Error>> = scope.spawn(move || {
-					let mut db = MemoryDB::new();
-					let status = try!(rebuild_accounts(&mut db, account_chunk, out_pairs_chunk, code_map));
-
-					trace!(target: "snapshot", "thread rebuilt {} account tries", account_chunk.len());
-					Ok((db, status))
-				});
-
-				handles.push(handle);
+		for (account_chunk, out_pairs_chunk) in account_fat_rlps.chunks(chunk_size).zip(pairs.chunks_mut(chunk_size)) {
+			let code_map = &self.code_map;
+			let status = try!(rebuild_accounts(self.db.as_hashdb_mut(), account_chunk, out_pairs_chunk, code_map));
+			chunk_code.extend(status.new_code);
+			for (addr_hash, code_hash) in status.missing_code {
+				self.missing_code.entry(code_hash).or_insert_with(Vec::new).push(addr_hash);
 			}
-
-			// consolidate all edits into the main overlay.
-			for handle in handles {
-				let (thread_db, status): (MemoryDB, _) = try!(handle.join());
-				self.db.consolidate(thread_db);
-
-				chunk_code.extend(status.new_code);
-
-				for (addr_hash, code_hash) in status.missing_code {
-					self.missing_code.entry(code_hash).or_insert_with(Vec::new).push(addr_hash);
-				}
-			}
-
-			Ok::<_, ::error::Error>(())
-		}));
-
+		}
 		// patch up all missing code. must be done after collecting all new missing code entries.
 		for (code_hash, code) in chunk_code {
 			for addr_hash in self.missing_code.remove(&code_hash).unwrap_or_else(Vec::new) {

ethcore/src/snapshot/service.rs

@@ -497,7 +497,7 @@ impl Service {
 							match is_done {
 								true => {
 									try!(db.flush().map_err(::util::UtilError::SimpleString));
-									self.finalize_restoration(&mut *restoration)
+									return self.finalize_restoration(&mut *restoration);
 								},
 								false => Ok(())
 							}