Clippy bump (#2877)

* Bumping clippy

* Fixing warnings

* Fix the "fix"

util/src/journaldb/archivedb.rs

@@ -78,7 +78,7 @@ impl HashDB for ArchiveDB {
 			ret.insert(h, 1);
 		}
 
-		for (key, refs) in self.overlay.keys().into_iter() {
+		for (key, refs) in self.overlay.keys() {
 			let refs = *ret.get(&key).unwrap_or(&0) + refs;
 			ret.insert(key, refs);
 		}
@@ -152,7 +152,7 @@ impl JournalDB for ArchiveDB {
 		let mut inserts = 0usize;
 		let mut deletes = 0usize;
 
-		for i in self.overlay.drain().into_iter() {
+		for i in self.overlay.drain() {
 			let (key, (value, rc)) = i;
 			if rc > 0 {
 				batch.put(self.column, &key, &value);
@@ -164,7 +164,7 @@ impl JournalDB for ArchiveDB {
 			}
 		}
 
-		for (mut key, value) in self.overlay.drain_aux().into_iter() {
+		for (mut key, value) in self.overlay.drain_aux() {
 			key.push(AUX_FLAG);
 			batch.put(self.column, &key, &value);
 		}
@@ -185,7 +185,7 @@ impl JournalDB for ArchiveDB {
 		let mut inserts = 0usize;
 		let mut deletes = 0usize;
 
-		for i in self.overlay.drain().into_iter() {
+		for i in self.overlay.drain() {
 			let (key, (value, rc)) = i;
 			if rc > 0 {
 				if try!(self.backing.get(self.column, &key)).is_some() {
@@ -204,7 +204,7 @@ impl JournalDB for ArchiveDB {
 			}
 		}
 
-		for (mut key, value) in self.overlay.drain_aux().into_iter() {
+		for (mut key, value) in self.overlay.drain_aux() {
 			key.push(AUX_FLAG);
 			batch.put(self.column, &key, &value);
 		}

util/src/journaldb/earlymergedb.rs

@@ -63,9 +63,11 @@ enum RemoveFrom {
 /// the removals actually take effect.
 ///
 /// journal format:
+/// ```
 /// [era, 0] => [ id, [insert_0, ...], [remove_0, ...] ]
 /// [era, 1] => [ id, [insert_0, ...], [remove_0, ...] ]
 /// [era, n] => [ ... ]
+/// ```
 ///
 /// When we make a new commit, we make a journal of all blocks in the recent history and record
 /// all keys that were inserted and deleted. The journal is ordered by era; multiple commits can
@@ -80,6 +82,7 @@ enum RemoveFrom {
 /// which includes an original key, if any.
 ///
 /// The semantics of the `counter` are:
+/// ```
 /// insert key k:
 ///   counter already contains k: count += 1
 ///   counter doesn't contain k:
@@ -91,9 +94,11 @@ enum RemoveFrom {
 ///     count == 1: remove counter
 ///     count == 0: remove key from backing db
 ///   counter doesn't contain k: remove key from backing db
+/// ```
 ///
 /// Practically, this means that for each commit block turning from recent to ancient we do the
 /// following:
+/// ```
 /// is_canonical:
 ///   inserts: Ignored (left alone in the backing database).
 ///   deletes: Enacted; however, recent history queue is checked for ongoing references. This is
@@ -102,8 +107,9 @@ enum RemoveFrom {
 ///   inserts: Reverted; however, recent history queue is checked for ongoing references. This is
 ///            reduced as a preference to deletion from the backing database.
 ///   deletes: Ignored (they were never inserted).
+/// ```
 ///
-/// TODO: store_reclaim_period
+/// TODO: `store_reclaim_period`
 pub struct EarlyMergeDB {
 	overlay: MemoryDB,
 	backing: Arc<Database>,
@@ -310,7 +316,7 @@ impl HashDB for EarlyMergeDB {
 			ret.insert(h, 1);
 		}
 
-		for (key, refs) in self.overlay.keys().into_iter() {
+		for (key, refs) in self.overlay.keys() {
 			let refs = *ret.get(&key).unwrap_or(&0) + refs;
 			ret.insert(key, refs);
 		}

util/src/journaldb/overlayrecentdb.rs

@@ -379,7 +379,7 @@ impl HashDB for OverlayRecentDB {
 			ret.insert(h, 1);
 		}
 
-		for (key, refs) in self.transaction_overlay.keys().into_iter() {
+		for (key, refs) in self.transaction_overlay.keys() {
 			let refs = *ret.get(&key).unwrap_or(&0) + refs;
 			ret.insert(key, refs);
 		}

util/src/journaldb/refcounteddb.rs

@@ -36,12 +36,14 @@ use std::env;
 /// the removals actually take effect.
 ///
 /// journal format:
+/// ```
 /// [era, 0] => [ id, [insert_0, ...], [remove_0, ...] ]
 /// [era, 1] => [ id, [insert_0, ...], [remove_0, ...] ]
 /// [era, n] => [ ... ]
+/// ```
 ///
 /// when we make a new commit, we journal the inserts and removes.
-/// for each end_era that we journaled that we are no passing by,
+/// for each `end_era` that we journaled that we are no passing by,
 /// we remove all of its removes assuming it is canonical and all
 /// of its inserts otherwise.
 // TODO: store last_era, reclaim_period.

util/src/migration/mod.rs

@@ -231,7 +231,7 @@ impl Manager {
 		trace!(target: "migration", "Total migrations to execute for version {}: {}", version, migrations.len());
 		if migrations.is_empty() { return Err(Error::MigrationImpossible) };
 
-		let columns = migrations.iter().nth(0).and_then(|m| m.pre_columns());
+		let columns = migrations.get(0).and_then(|m| m.pre_columns());
 
 		trace!(target: "migration", "Expecting database to contain {:?} columns", columns);
 		let mut db_config = DatabaseConfig {

util/src/overlaydb.rs

@@ -66,7 +66,7 @@ impl OverlayDB {
 	pub fn commit_to_batch(&mut self, batch: &mut DBTransaction) -> Result<u32, UtilError> {
 		let mut ret = 0u32;
 		let mut deletes = 0usize;
-		for i in self.overlay.drain().into_iter() {
+		for i in self.overlay.drain() {
 			let (key, (value, rc)) = i;
 			if rc != 0 {
 				match self.payload(&key) {
@@ -133,7 +133,7 @@ impl HashDB for OverlayDB {
 			ret.insert(h, r as i32);
 		}
 
-		for (key, refs) in self.overlay.keys().into_iter() {
+		for (key, refs) in self.overlay.keys() {
 			let refs = *ret.get(&key).unwrap_or(&0) + refs;
 			ret.insert(key, refs);
 		}

util/src/trie/journal.rs

@@ -84,7 +84,7 @@ impl Journal {
 	pub fn apply(self, db: &mut HashDB) -> Score {
 		trace!("applying {:?} changes", self.0.len());
 		let mut ret = Score{inserts: 0, removes: 0};
-		for d in self.0.into_iter() {
+		for d in self.0 {
 			match d {
 				Operation::Delete(h) => {
 					trace!("TrieDBMut::apply --- {:?}", &h);

util/src/trie/triedb.rs

@@ -87,7 +87,7 @@ impl<'db> TrieDB<'db> {
 	/// Convert a vector of hashes to a hashmap of hash to occurrences.
 	pub fn to_map(hashes: Vec<H256>) -> HashMap<H256, u32> {
 		let mut r: HashMap<H256, u32> = HashMap::new();
-		for h in hashes.into_iter() {
+		for h in hashes {
 			*r.entry(h).or_insert(0) += 1;
 		}
 		r
@@ -97,7 +97,7 @@ impl<'db> TrieDB<'db> {
 	/// trie.
 	pub fn db_items_remaining(&self) -> super::Result<HashMap<H256, i32>> {
 		let mut ret = self.db.keys();
-		for (k, v) in Self::to_map(try!(self.keys())).into_iter() {
+		for (k, v) in Self::to_map(try!(self.keys())) {
 			let keycount = *ret.get(&k).unwrap_or(&0);
 			match keycount <= v as i32 {
 				true => ret.remove(&k),