[journaldb]: cleanup (#11534)

I was annoyed by the manual `clone` implementations which this removes and I fixed a few of clippy warnings.

util/journaldb/src/archivedb.rs

@@ -42,6 +42,7 @@ use crate::{
 /// write operations out to disk. Unlike `OverlayDB`, `remove()` operations do not take effect
 /// immediately. As this is an "archive" database, nothing is ever removed. This means
 /// that the states of any block the node has ever processed will be accessible.
+#[derive(Clone)]
 pub struct ArchiveDB {
 	overlay: super::MemoryDB,
 	backing: Arc<dyn KeyValueDB>,
@@ -98,12 +99,7 @@ impl HashDB<KeccakHasher, DBValue> for ArchiveDB {
 
 impl JournalDB for ArchiveDB {
 	fn boxed_clone(&self) -> Box<dyn JournalDB> {
-		Box::new(ArchiveDB {
+		Box::new(self.clone())
-			overlay: self.overlay.clone(),
-			backing: self.backing.clone(),
-			latest_era: self.latest_era,
-			column: self.column.clone(),
-		})
 	}
 
 	fn mem_used(&self) -> usize {

util/journaldb/src/earlymergedb.rs

@@ -106,6 +106,7 @@ enum RemoveFrom {
 /// ```
 ///
 /// TODO: `store_reclaim_period`
+#[derive(Clone)]
 pub struct EarlyMergeDB {
 	overlay: super::MemoryDB,
 	backing: Arc<dyn KeyValueDB>,
@@ -167,7 +168,7 @@ impl EarlyMergeDB {
 					}
 					entry.insert(RefInfo {
 						queue_refs: 1,
-						in_archive: in_archive,
+						in_archive,
 					});
 				},
 			}
@@ -318,13 +319,7 @@ impl HashDB<KeccakHasher, DBValue> for EarlyMergeDB {
 
 impl JournalDB for EarlyMergeDB {
 	fn boxed_clone(&self) -> Box<dyn JournalDB> {
-		Box::new(EarlyMergeDB {
+		Box::new(self.clone())
-			overlay: self.overlay.clone(),
-			backing: self.backing.clone(),
-			refs: self.refs.clone(),
-			latest_era: self.latest_era.clone(),
-			column: self.column.clone(),
-		})
 	}
 
 	fn is_empty(&self) -> bool {
@@ -376,7 +371,7 @@ impl JournalDB for EarlyMergeDB {
 
 			let removes: Vec<H256> = drained
 				.iter()
-				.filter_map(|(k, &(_, c))| if c < 0 {Some(k.clone())} else {None})
+				.filter_map(|(k, &(_, c))| if c < 0 { Some(*k) } else { None })
 				.collect();
 			let inserts: Vec<(H256, _)> = drained
 				.into_iter()

util/journaldb/src/overlayrecentdb.rs

@@ -70,6 +70,7 @@ use crate::{
 /// the removed key is not present in the history overlay.
 /// 7. Delete ancient record from memory and disk.
 
+#[derive(Clone)]
 pub struct OverlayRecentDB {
 	transaction_overlay: super::MemoryDB,
 	backing: Arc<dyn KeyValueDB>,
@@ -140,17 +141,6 @@ struct JournalEntry {
 	deletions: Vec<H256>,
 }
 
-impl Clone for OverlayRecentDB {
-	fn clone(&self) -> OverlayRecentDB {
-		OverlayRecentDB {
-			transaction_overlay: self.transaction_overlay.clone(),
-			backing: self.backing.clone(),
-			journal_overlay: self.journal_overlay.clone(),
-			column: self.column.clone(),
-		}
-	}
-}
-
 impl OverlayRecentDB {
 	/// Create a new instance.
 	pub fn new(backing: Arc<dyn KeyValueDB>, col: u32) -> OverlayRecentDB {
@@ -197,7 +187,11 @@ impl OverlayRecentDB {
 				};
 				while let Some(rlp_data) = db.get(col, &encode(&db_key)).expect("Low-level database error.") {
 					trace!("read_overlay: era={}, index={}", era, db_key.index);
-					let value = decode::<DatabaseValue>(&rlp_data).expect(&format!("read_overlay: Error decoding DatabaseValue era={}, index{}", era, db_key.index));
+					let value = decode::<DatabaseValue>(&rlp_data).unwrap_or_else(|e| {
+						panic!("read_overlay: Error decoding DatabaseValue era={}, index={}, error={}",
+							era, db_key.index, e
+						)
+					});
 					count += value.inserts.len();
 					let mut inserted_keys = Vec::new();
 					for (k, v) in value.inserts {
@@ -286,7 +280,7 @@ impl JournalDB for OverlayRecentDB {
 			journal_overlay
 				.backing_overlay
 				.get(&key, EMPTY_PREFIX)
-				.or_else(|| journal_overlay.pending_overlay.get(&key).map(|d| d.clone()))
+				.or_else(|| journal_overlay.pending_overlay.get(&key).cloned())
 		};
 
 		maybe_state_data.or_else(|| {
@@ -306,8 +300,8 @@ impl JournalDB for OverlayRecentDB {
 		journal_overlay.pending_overlay.clear();
 
 		let mut tx = self.transaction_overlay.drain();
-		let inserted_keys: Vec<_> = tx.iter().filter_map(|(k, &(_, c))| if c > 0 { Some(k.clone()) } else { None }).collect();
+		let inserted_keys: Vec<_> = tx.iter().filter_map(|(k, &(_, c))| if c > 0 { Some(*k) } else { None }).collect();
-		let removed_keys: Vec<_> = tx.iter().filter_map(|(k, &(_, c))| if c < 0 { Some(k.clone()) } else { None }).collect();
+		let removed_keys: Vec<_> = tx.iter().filter_map(|(k, &(_, c))| if c < 0 { Some(*k) } else { None }).collect();
 		let ops = inserted_keys.len() + removed_keys.len();
 
 		// Increase counter for each inserted key no matter if the block is canonical or not.
@@ -349,7 +343,10 @@ impl JournalDB for OverlayRecentDB {
 			journal_overlay.earliest_era = Some(now);
 		}
 
-		journal_overlay.journal.entry(now).or_insert_with(Vec::new).push(JournalEntry { id: id.clone(), insertions: inserted_keys, deletions: removed_keys });
+		journal_overlay.journal
+			.entry(now)
+			.or_insert_with(Vec::new)
+			.push(JournalEntry { id: *id, insertions: inserted_keys, deletions: removed_keys });
 		Ok(ops as u32)
 	}
 
@@ -365,8 +362,7 @@ impl JournalDB for OverlayRecentDB {
 			let mut canon_insertions: Vec<(H256, DBValue)> = Vec::new();
 			let mut canon_deletions: Vec<H256> = Vec::new();
 			let mut overlay_deletions: Vec<H256> = Vec::new();
-			let mut index = 0usize;
+			for (index, mut journal) in records.drain(..).enumerate() {
-			for mut journal in records.drain(..) {
 				//delete the record from the db
 				let db_key = DatabaseKey {
 					era: end_era,
@@ -379,7 +375,7 @@ impl JournalDB for OverlayRecentDB {
 						for h in &journal.insertions {
 							if let Some((d, rc)) = journal_overlay.backing_overlay.raw(&to_short_key(h), EMPTY_PREFIX) {
 								if rc > 0 {
-									canon_insertions.push((h.clone(), d.clone())); //TODO: optimize this to avoid data copy
+									canon_insertions.push((*h, d.clone())); //TODO: optimize this to avoid data copy
 								}
 							}
 						}
@@ -387,7 +383,6 @@ impl JournalDB for OverlayRecentDB {
 					}
 					overlay_deletions.append(&mut journal.insertions);
 				}
-				index += 1;
 			}
 
 			ops += canon_insertions.len();

util/journaldb/src/refcounteddb.rs

@@ -57,6 +57,7 @@ use crate::{
 /// we remove all of its removes assuming it is canonical and all
 /// of its inserts otherwise.
 // TODO: store last_era, reclaim_period.
+#[derive(Clone)]
 pub struct RefCountedDB {
 	forward: OverlayDB,
 	backing: Arc<dyn KeyValueDB>,
@@ -88,20 +89,13 @@ impl HashDB<KeccakHasher, DBValue> for RefCountedDB {
 	fn get(&self, key: &H256, prefix: Prefix) -> Option<DBValue> { self.forward.get(key, prefix) }
 	fn contains(&self, key: &H256, prefix: Prefix) -> bool { self.forward.contains(key, prefix) }
 	fn insert(&mut self, prefix: Prefix, value: &[u8]) -> H256 { let r = self.forward.insert(prefix, value); self.inserts.push(r.clone()); r }
-	fn emplace(&mut self, key: H256, prefix: Prefix, value: DBValue) { self.inserts.push(key.clone()); self.forward.emplace(key, prefix, value); }
+	fn emplace(&mut self, key: H256, prefix: Prefix, value: DBValue) { self.inserts.push(key); self.forward.emplace(key, prefix, value); }
-	fn remove(&mut self, key: &H256, _prefix: Prefix) { self.removes.push(key.clone()); }
+	fn remove(&mut self, key: &H256, _prefix: Prefix) { self.removes.push(*key); }
 }
 
 impl JournalDB for RefCountedDB {
 	fn boxed_clone(&self) -> Box<dyn JournalDB> {
-		Box::new(RefCountedDB {
+		Box::new(self.clone())
-			forward: self.forward.clone(),
-			backing: self.backing.clone(),
-			latest_era: self.latest_era,
-			inserts: self.inserts.clone(),
-			removes: self.removes.clone(),
-			column: self.column.clone(),
-		})
 	}
 
 	fn mem_used(&self) -> usize {