Merge pull request #6773 from paritytech/refactoring/redundant-mut

Remove redundant `mut`

ethcore/src/account_provider/stores.rs

@@ -64,7 +64,7 @@ impl AddressBook {
 	/// Sets new name for given address.
 	pub fn set_name(&mut self, a: Address, name: String) {
 		{
-			let mut x = self.cache.entry(a)
+			let x = self.cache.entry(a)
 				.or_insert_with(|| AccountMeta {name: Default::default(), meta: "{}".to_owned(), uuid: None});
 			x.name = name;
 		}
@@ -74,7 +74,7 @@ impl AddressBook {
 	/// Sets new meta for given address.
 	pub fn set_meta(&mut self, a: Address, meta: String) {
 		{
-			let mut x = self.cache.entry(a)
+			let x = self.cache.entry(a)
 				.or_insert_with(|| AccountMeta {name: "Anonymous".to_owned(), meta: Default::default(), uuid: None});
 			x.meta = meta;
 		}
@@ -253,7 +253,7 @@ impl DappsSettingsStore {
 	/// Marks recent dapp as used
 	pub fn mark_dapp_used(&mut self, dapp: DappId) {
 		{
-			let mut entry = self.history.entry(dapp).or_insert_with(|| Default::default());
+			let entry = self.history.entry(dapp).or_insert_with(|| Default::default());
 			entry.last_accessed = self.time.get();
 		}
 		// Clear extraneous entries
@@ -280,7 +280,7 @@ impl DappsSettingsStore {
 	/// Sets accounts for specific dapp.
 	pub fn set_accounts(&mut self, id: DappId, accounts: Option<Vec<Address>>) {
 		{
-			let mut settings = self.settings.entry(id).or_insert_with(DappsSettings::default);
+			let settings = self.settings.entry(id).or_insert_with(DappsSettings::default);
 			settings.accounts = accounts;
 		}
 		self.settings.save(JsonSettings::write);
@@ -289,7 +289,7 @@ impl DappsSettingsStore {
 	/// Sets a default account for specific dapp.
 	pub fn set_default(&mut self, id: DappId, default: Address) {
 		{
-			let mut settings = self.settings.entry(id).or_insert_with(DappsSettings::default);
+			let settings = self.settings.entry(id).or_insert_with(DappsSettings::default);
 			settings.default = Some(default);
 		}
 		self.settings.save(JsonSettings::write);

ethcore/src/engines/mod.rs

@@ -421,7 +421,7 @@ pub mod common {
 			.and_then(|_| fields.state.commit());
 
 		let block_author = fields.header.author().clone();
-		fields.traces.as_mut().map(move |mut traces| {
+		fields.traces.as_mut().map(move |traces| {
   			let mut tracer = ExecutiveTracer::default();
   			tracer.trace_reward(block_author, reward, RewardType::Block);
   			traces.push(tracer.drain())

ethcore/src/executive.rs

@@ -433,7 +433,7 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
 					// trace only top level calls to builtins to avoid DDoS attacks
 					if self.depth == 0 {
 						let mut trace_output = tracer.prepare_trace_output();
-						if let Some(mut out) = trace_output.as_mut() {
+						if let Some(out) = trace_output.as_mut() {
 							*out = output.to_owned();
 						}
 

ethcore/src/miner/banning_queue.rs

@@ -149,7 +149,7 @@ impl BanningTransactionQueue {
 	/// queue.
 	fn ban_sender(&mut self, address: Address) -> bool {
 		let count = {
-			let mut count = self.senders_bans.entry(address).or_insert_with(|| 0);
+			let count = self.senders_bans.entry(address).or_insert_with(|| 0);
 			*count = count.saturating_add(1);
 			*count
 		};
@@ -169,7 +169,7 @@ impl BanningTransactionQueue {
 	/// Returns true if bans threshold has been reached.
 	fn ban_recipient(&mut self, address: Address) -> bool {
 		let count = {
-			let mut count = self.recipients_bans.entry(address).or_insert_with(|| 0);
+			let count = self.recipients_bans.entry(address).or_insert_with(|| 0);
 			*count = count.saturating_add(1);
 			*count
 		};
@@ -185,7 +185,7 @@ impl BanningTransactionQueue {
 	/// If bans threshold is reached all subsequent transactions to contracts with this codehash will be rejected.
 	/// Returns true if bans threshold has been reached.
 	fn ban_codehash(&mut self, code_hash: H256) -> bool {
-		let mut count = self.codes_bans.entry(code_hash).or_insert_with(|| 0);
+		let count = self.codes_bans.entry(code_hash).or_insert_with(|| 0);
 		*count = count.saturating_add(1);
 
 		match self.ban_threshold {

ethcore/src/miner/transaction_queue.rs

@@ -341,7 +341,7 @@ impl GasPriceQueue {
 	/// Remove an item from a BTreeMap/HashSet "multimap".
 	/// Returns true if the item was removed successfully.
 	pub fn remove(&mut self, gas_price: &U256, hash: &H256) -> bool {
-		if let Some(mut hashes) = self.backing.get_mut(gas_price) {
+		if let Some(hashes) = self.backing.get_mut(gas_price) {
 			let only_one_left = hashes.len() == 1;
 			if !only_one_left {
 				// Operation may be ok: only if hash is in gas-price's Set.
@@ -1225,7 +1225,7 @@ impl TransactionQueue {
 			if by_nonce.is_none() {
 				return;
 			}
-			let mut by_nonce = by_nonce.expect("None is tested in early-exit condition above; qed");
+			let by_nonce = by_nonce.expect("None is tested in early-exit condition above; qed");
 			while let Some(order) = by_nonce.remove(&current_nonce) {
 				// remove also from priority and gas_price
 				self.future.by_priority.remove(&order);

ethcore/src/state/mod.rs

@@ -962,7 +962,7 @@ impl<B: Backend> State<B> {
 
 		// at this point the entry is guaranteed to be in the cache.
 		Ok(RefMut::map(self.cache.borrow_mut(), |c| {
-			let mut entry = c.get_mut(a).expect("entry known to exist in the cache; qed");
+			let entry = c.get_mut(a).expect("entry known to exist in the cache; qed");
 
 			match &mut entry.account {
 				&mut Some(ref mut acc) => not_default(acc),

ethcore/src/state_db.rs

@@ -211,7 +211,7 @@ impl StateDB {
 	pub fn sync_cache(&mut self, enacted: &[H256], retracted: &[H256], is_best: bool) {
 		trace!("sync_cache id = (#{:?}, {:?}), parent={:?}, best={}", self.commit_number, self.commit_hash, self.parent_hash, is_best);
 		let mut cache = self.account_cache.lock();
-		let mut cache = &mut *cache;
+		let cache = &mut *cache;
 
 		// Purge changes from re-enacted and retracted blocks.
 		// Filter out commiting block if any.

ethcore/src/verification/queue/mod.rs

@@ -522,7 +522,7 @@ impl<K: Kind> VerificationQueue<K> {
 			return;
 		}
 		let mut verified_lock = self.verification.verified.lock();
-		let mut verified = &mut *verified_lock;
+		let verified = &mut *verified_lock;
 		let mut bad = self.verification.bad.lock();
 		let mut processing = self.processing.write();
 		bad.reserve(hashes.len());

ethstore/src/dir/memory.rs

@@ -35,7 +35,7 @@ impl KeyDirectory for MemoryDirectory {
 
 	fn update(&self, account: SafeAccount) -> Result<SafeAccount, Error> {
 		let mut lock = self.accounts.write();
-		let mut accounts = lock.entry(account.address.clone()).or_insert_with(Vec::new);
+		let accounts = lock.entry(account.address.clone()).or_insert_with(Vec::new);
 		// If the filename is the same we just need to replace the entry
 		accounts.retain(|acc| acc.filename != account.filename);
 		accounts.push(account.clone());
@@ -44,14 +44,14 @@ impl KeyDirectory for MemoryDirectory {
 
 	fn insert(&self, account: SafeAccount) -> Result<SafeAccount, Error> {
 		let mut lock = self.accounts.write();
-		let mut accounts = lock.entry(account.address.clone()).or_insert_with(Vec::new);
+		let accounts = lock.entry(account.address.clone()).or_insert_with(Vec::new);
 		accounts.push(account.clone());
 		Ok(account)
 	}
 
 	fn remove(&self, account: &SafeAccount) -> Result<(), Error> {
 		let mut accounts = self.accounts.write();
-		let is_empty = if let Some(mut accounts) = accounts.get_mut(&account.address) {
+		let is_empty = if let Some(accounts) = accounts.get_mut(&account.address) {
 			if let Some(position) = accounts.iter().position(|acc| acc == account) {
 				accounts.remove(position);
 			}

ethstore/src/ethstore.rs

@@ -358,7 +358,7 @@ impl EthMultiStore {
 
 		// update cache
 		let mut cache = self.cache.write();
-		let mut accounts = cache.entry(account_ref.clone()).or_insert_with(Vec::new);
+		let accounts = cache.entry(account_ref.clone()).or_insert_with(Vec::new);
 		// Remove old account
 		accounts.retain(|acc| acc != &old);
 		// And push updated to the end

hw/src/ledger.rs

@@ -255,7 +255,7 @@ impl Manager {
 			let mut chunk_size = if chunk_index == 0 { 12 } else { 5 };
 			let size = min(64 - chunk_size, data.len() - offset);
 			{
-				let mut chunk = &mut hid_chunk[HID_PREFIX_ZERO..];
+				let chunk = &mut hid_chunk[HID_PREFIX_ZERO..];
 				&mut chunk[0..5].copy_from_slice(&[0x01, 0x01, APDU_TAG, (chunk_index >> 8) as u8, (chunk_index & 0xff) as u8 ]);
 
 				if chunk_index == 0 {

rpc/src/authcodes.rs

@@ -176,7 +176,7 @@ impl<T: TimeProvider> AuthCodes<T> {
 		}
 
 		// look for code
-		for mut code in &mut self.codes {
+		for code in &mut self.codes {
 			if &as_token(&code.code) == hash {
 				code.last_used_at = Some(time::Duration::from_secs(now));
 				return true;

rpc/src/v1/extractors.rs

@@ -136,7 +136,7 @@ impl ws::RequestMiddleware for WsExtractor {
 }
 
 fn add_security_headers(res: &mut ws::ws::Response) {
-	let mut headers = res.headers_mut();
+	let headers = res.headers_mut();
 	headers.push(("X-Frame-Options".into(), b"SAMEORIGIN".to_vec()));
 	headers.push(("X-XSS-Protection".into(), b"1; mode=block".to_vec()));
 	headers.push(("X-Content-Type-Options".into(), b"nosniff".to_vec()));

sync/src/chain.rs

@@ -459,7 +459,7 @@ impl ChainSync {
 
 	/// Updates transactions were received by a peer
 	pub fn transactions_received(&mut self, hashes: Vec<H256>, peer_id: PeerId) {
-		if let Some(mut peer_info) = self.peers.get_mut(&peer_id) {
+		if let Some(peer_info) = self.peers.get_mut(&peer_id) {
 			peer_info.last_sent_transactions.extend(&hashes);
 		}
 	}
@@ -730,7 +730,7 @@ impl ChainSync {
 		}
 
 		let result =  {
-			let mut downloader = match block_set {
+			let downloader = match block_set {
 				BlockSet::NewBlocks => &mut self.new_blocks,
 				BlockSet::OldBlocks => {
 					match self.old_blocks {
@@ -795,7 +795,7 @@ impl ChainSync {
 		else
 		{
 			let result = {
-				let mut downloader = match block_set {
+				let downloader = match block_set {
 					BlockSet::NewBlocks => &mut self.new_blocks,
 					BlockSet::OldBlocks => match self.old_blocks {
 						None => {
@@ -849,7 +849,7 @@ impl ChainSync {
 		else
 		{
 			let result = {
-				let mut downloader = match block_set {
+				let downloader = match block_set {
 					BlockSet::NewBlocks => &mut self.new_blocks,
 					BlockSet::OldBlocks => match self.old_blocks {
 						None => {
@@ -2186,7 +2186,7 @@ impl ChainSync {
 			// Select random peer to re-broadcast transactions to.
 			let peer = random::new().gen_range(0, self.peers.len());
 			trace!(target: "sync", "Re-broadcasting transactions to a random peer.");
-			self.peers.values_mut().nth(peer).map(|mut peer_info|
+			self.peers.values_mut().nth(peer).map(|peer_info|
 				peer_info.last_sent_transactions.clear()
 			);
 		}

sync/src/transactions_stats.rs

@@ -57,8 +57,8 @@ impl TransactionsStats {
 	/// Increases number of propagations to given `enodeid`.
 	pub fn propagated(&mut self, hash: &H256, enode_id: Option<NodeId>, current_block_num: BlockNumber) {
 		let enode_id = enode_id.unwrap_or_default();
-		let mut stats = self.pending_transactions.entry(*hash).or_insert_with(|| Stats::new(current_block_num));
+		let stats = self.pending_transactions.entry(*hash).or_insert_with(|| Stats::new(current_block_num));
-		let mut count = stats.propagated_to.entry(enode_id).or_insert(0);
+		let count = stats.propagated_to.entry(enode_id).or_insert(0);
 		*count = count.saturating_add(1);
 	}
 

util/kvdb/src/lib.rs

@@ -254,12 +254,12 @@ impl KeyValueDB for InMemory {
 		for op in ops {
 			match op {
 				DBOp::Insert { col, key, value } => {
-					if let Some(mut col) = columns.get_mut(&col) {
+					if let Some(col) = columns.get_mut(&col) {
 						col.insert(key.into_vec(), value);
 					}
 				},
 				DBOp::InsertCompressed { col, key, value } => {
-					if let Some(mut col) = columns.get_mut(&col) {
+					if let Some(col) = columns.get_mut(&col) {
 						let compressed = UntrustedRlp::new(&value).compress(RlpType::Blocks);
 						let mut value = DBValue::new();
 						value.append_slice(&compressed);
@@ -267,7 +267,7 @@ impl KeyValueDB for InMemory {
 					}
 				},
 				DBOp::Delete { col, key } => {
-					if let Some(mut col) = columns.get_mut(&col) {
+					if let Some(col) = columns.get_mut(&col) {
 						col.remove(&*key);
 					}
 				},

util/network/src/discovery.rs

@@ -156,7 +156,7 @@ impl Discovery {
 		trace!(target: "discovery", "Inserting {:?}", &e);
 		let id_hash = keccak(e.id);
 		let ping = {
-			let mut bucket = &mut self.node_buckets[Discovery::distance(&self.id_hash, &id_hash) as usize];
+			let bucket = &mut self.node_buckets[Discovery::distance(&self.id_hash, &id_hash) as usize];
 			let updated = if let Some(node) = bucket.nodes.iter_mut().find(|n| n.address.id == e.id) {
 				node.address = e.clone();
 				node.timeout = None;
@@ -169,7 +169,7 @@ impl Discovery {
 
 			if bucket.nodes.len() > BUCKET_SIZE {
 				//ping least active node
-				let mut last = bucket.nodes.back_mut().expect("Last item is always present when len() > 0");
+				let last = bucket.nodes.back_mut().expect("Last item is always present when len() > 0");
 				last.timeout = Some(time::precise_time_ns());
 				Some(last.address.endpoint.clone())
 			} else { None }
@@ -180,7 +180,7 @@ impl Discovery {
 	}
 
 	fn clear_ping(&mut self, id: &NodeId) {
-		let mut bucket = &mut self.node_buckets[Discovery::distance(&self.id_hash, &keccak(id)) as usize];
+		let bucket = &mut self.node_buckets[Discovery::distance(&self.id_hash, &keccak(id)) as usize];
 		if let Some(node) = bucket.nodes.iter_mut().find(|n| &n.address.id == id) {
 			node.timeout = None;
 		}

util/network/src/node_table.rs

@@ -253,7 +253,7 @@ impl NodeTable {
 	/// Apply table changes coming from discovery
 	pub fn update(&mut self, mut update: TableUpdates, reserved: &HashSet<NodeId>) {
 		for (_, node) in update.added.drain() {
-			let mut entry = self.nodes.entry(node.id.clone()).or_insert_with(|| Node::new(node.id.clone(), node.endpoint.clone()));
+			let entry = self.nodes.entry(node.id.clone()).or_insert_with(|| Node::new(node.id.clone(), node.endpoint.clone()));
 			entry.endpoint = node.endpoint;
 		}
 		for r in update.removed {

util/table/src/lib.rs

@@ -91,7 +91,7 @@ impl<Row, Col, Val> Table<Row, Col, Val>
 			if let None = row_map {
 				return None;
 			}
-			let mut row_map = row_map.unwrap();
+			let row_map = row_map.unwrap();
 			let val = row_map.remove(col);
 			(val, row_map.is_empty())
 		};