Purging .derefs, fixing clippy warnings. (#1890)

* Fixing clippy warnings

* Purging derefs

* Simplifying engine derefs

* Simplifying more engine derefs

ethcore/src/snapshot/error.rs

@@ -64,9 +64,9 @@ impl From<::std::io::Error> for Error {
 	}
 }
 
-impl From<Box<TrieError>> for Error {
-	fn from(err: Box<TrieError>) -> Self {
-		Error::Trie(*err)
+impl From<TrieError> for Error {
+	fn from(err: TrieError) -> Self {
+		Error::Trie(err)
 	}
 }
 
@@ -74,4 +74,10 @@ impl From<DecoderError> for Error {
 	fn from(err: DecoderError) -> Self {
 		Error::Decoder(err)
 	}
-}
+}
+
+impl<E> From<Box<E>> for Error where Error: From<E> {
+	fn from(err: Box<E>) -> Self {
+		Error::from(*err)
+	}
+}

ethcore/src/snapshot/mod.rs

@@ -61,7 +61,7 @@ const PREFERRED_CHUNK_SIZE: usize = 4 * 1024 * 1024;
 const SNAPSHOT_BLOCKS: u64 = 30000;
 
 /// A progress indicator for snapshots.
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct Progress {
 	accounts: AtomicUsize,
 	blocks: AtomicUsize,
@@ -70,16 +70,6 @@ pub struct Progress {
 }
 
 impl Progress {
-	/// Create a new progress indicator.
-	pub fn new() -> Self {
-		Progress {
-			accounts: AtomicUsize::new(0),
-			blocks: AtomicUsize::new(0),
-			size: AtomicUsize::new(0),
-			done: AtomicBool::new(false),
-		}
-	}
-
 	/// Get the number of accounts snapshotted thus far.
 	pub fn accounts(&self) -> usize { self.accounts.load(Ordering::Relaxed) }
 
@@ -510,12 +500,12 @@ fn rebuild_account_trie(db: &mut HashDB, account_chunk: &[&[u8]], out_chunk: &mu
 	Ok(())
 }
 
-/// Proportion of blocks which we will verify PoW for.
+/// Proportion of blocks which we will verify `PoW` for.
 const POW_VERIFY_RATE: f32 = 0.02;
 
 /// Rebuilds the blockchain from chunks.
 ///
-/// Does basic verification for all blocks, but PoW verification for some.
+/// Does basic verification for all blocks, but `PoW` verification for some.
 /// Blocks must be fed in-order.
 ///
 /// The first block in every chunk is disconnected from the last block in the

ethcore/src/snapshot/service.rs

@@ -101,7 +101,7 @@ impl Restoration {
 	fn new(manifest: &ManifestData, pruning: Algorithm, path: &Path, gb: &[u8]) -> Result<Self, Error> {
 		let cfg = DatabaseConfig::with_columns(::client::DB_NO_OF_COLUMNS);
 		let raw_db = Arc::new(try!(Database::open(&cfg, &*path.to_string_lossy())
-			.map_err(|s| UtilError::SimpleString(s))));
+			.map_err(UtilError::SimpleString)));
 
 		let chain = BlockChain::new(Default::default(), gb, raw_db.clone());
 		let blocks = try!(BlockRebuilder::new(chain, manifest.block_number));
@@ -207,23 +207,17 @@ impl Service {
 		};
 
 		// create the snapshot dir if it doesn't exist.
-		match fs::create_dir_all(service.snapshot_dir()) {
-			Err(e) => {
-				if e.kind() != ErrorKind::AlreadyExists {
-					return Err(e.into())
-				}
+		if let Err(e) = fs::create_dir_all(service.snapshot_dir()) {
+			if e.kind() != ErrorKind::AlreadyExists {
+				return Err(e.into())
 			}
-			_ => {}
 		}
 
 		// delete the temporary restoration dir if it does exist.
-		match fs::remove_dir_all(service.restoration_dir()) {
-			Err(e) => {
-				if e.kind() != ErrorKind::NotFound {
-					return Err(e.into())
-				}
+		if let Err(e) = fs::remove_dir_all(service.restoration_dir()) {
+			if e.kind() != ErrorKind::NotFound {
+				return Err(e.into())
 			}
-			_ => {}
 		}
 
 		Ok(service)
@@ -434,4 +428,4 @@ impl SnapshotService for Service {
 		self.io_channel.send(ClientIoMessage::FeedBlockChunk(hash, chunk))
 			.expect("snapshot service and io service are kept alive by client service; qed");
 	}
-}
+}

ethcore/src/snapshot/tests/blocks.rs

@@ -55,7 +55,7 @@ fn chunk_and_restore(amount: u64) {
 
 	// snapshot it.
 	let writer = Mutex::new(PackedWriter::new(&snapshot_path).unwrap());
-	let block_hashes = chunk_blocks(&bc, (amount, best_hash), &writer, &Progress::new()).unwrap();
+	let block_hashes = chunk_blocks(&bc, (amount, best_hash), &writer, &Progress::default()).unwrap();
 	writer.into_inner().finish(::snapshot::ManifestData {
 		state_hashes: Vec::new(),
 		block_hashes: block_hashes,
@@ -88,4 +88,4 @@ fn chunk_and_restore(amount: u64) {
 fn chunk_and_restore_500() { chunk_and_restore(500) }
 
 #[test]
-fn chunk_and_restore_40k() { chunk_and_restore(40000) }
+fn chunk_and_restore_40k() { chunk_and_restore(40000) }

ethcore/src/snapshot/tests/helpers.rs

@@ -116,7 +116,7 @@ pub fn fill_storage(mut db: AccountDBMut, root: &mut H256, seed: &mut H256) {
 pub fn compare_dbs(one: &HashDB, two: &HashDB) {
 	let keys = one.keys();
 
-	for (key, _) in keys {
+	for key in keys.keys() {
 		assert_eq!(one.get(&key).unwrap(), two.get(&key).unwrap());
 	}
-}
+}

ethcore/src/snapshot/tests/state.rs

@@ -48,7 +48,7 @@ fn snap_and_restore() {
 	let state_root = producer.state_root();
 	let writer = Mutex::new(PackedWriter::new(&snap_file).unwrap());
 
-	let state_hashes = chunk_state(&old_db, &state_root, &writer, &Progress::new()).unwrap();
+	let state_hashes = chunk_state(&old_db, &state_root, &writer, &Progress::default()).unwrap();
 
 	writer.into_inner().finish(::snapshot::ManifestData {
 		state_hashes: state_hashes,
@@ -79,4 +79,4 @@ fn snap_and_restore() {
 	let new_db = journaldb::new(db, Algorithm::Archive, ::client::DB_COL_STATE);
 
 	compare_dbs(&old_db, new_db.as_hashdb());
-}
+}