Fix wrong comments

Author: Seulgi Kim

util/hashdb/src/lib.rs

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Database of byte-slices keyed to their Keccak hash.
+//! Database of byte-slices keyed to their blake2b hash.
 extern crate primitives;
 
 use primitives::H256;
@@ -23,7 +23,7 @@ use std::collections::HashMap;
 /// `HashDB` value type.
 pub type DBValue = Vec<u8>;
 
-/// Trait modelling datastore keyed by a 32-byte Keccak hash.
+/// Trait modelling datastore keyed by a 32-byte blake2b hash.
 pub trait HashDB: AsHashDB + Send + Sync {
     /// Get the keys in the database together with number of underlying references.
     fn keys(&self) -> HashMap<H256, i32>;
@@ -32,7 +32,7 @@ pub trait HashDB: AsHashDB + Send + Sync {
     /// hash is not known.
     fn get(&self, key: &H256) -> Option<DBValue>;
 
-    /// Check for the existance of a hash-key.
+    /// Check for the existence of a hash-key.
     fn contains(&self, key: &H256) -> bool;
 
     /// Insert a datum item into the DB and return the datum's hash for a later lookup. Insertions

util/journaldb/src/traits.rs

@@ -44,7 +44,7 @@ pub trait JournalDB: HashDB {
     fn latest_era(&self) -> Option<u64>;
 
     /// Journal recent database operations as being associated with a given era and id.
-    // TODO: give the overlay to this function so journaldbs don't manage the overlays themeselves.
+    // TODO: give the overlay to this function so journaldbs don't manage the overlays themselves.
     fn journal_under(&mut self, batch: &mut DBTransaction, now: u64, id: &H256) -> Result<u32, UtilError>;
 
     /// Mark a given block as canonical, indicating that competing blocks' states may be pruned out.
@@ -70,8 +70,8 @@ pub trait JournalDB: HashDB {
     /// Get backing database.
     fn backing(&self) -> &Arc<dyn kvdb::KeyValueDB>;
 
-    /// Clear internal strucutres. This should called after changes have been written
-    /// to the backing strage
+    /// Clear internal structures. This should called after changes have been written
+    /// to the backing storage.
     fn flush(&self) {}
 
     /// Consolidate all the insertions and deletions in the given memory overlay.

util/merkle/src/lib.rs

@@ -68,7 +68,7 @@ pub type Result<T> = ::std::result::Result<T, TrieError>;
 /// Description of what kind of query will be made to the trie.
 pub type Query<T> = dyn Fn(&[u8]) -> T;
 
-/// A key-value datastore implemented as a database-backed modified Merkle tree.
+/// A key-value datastore implemented as a database-backed Merkle trie.
 pub trait Trie {
     /// Return the root of the trie.
     fn root(&self) -> &H256;
@@ -93,7 +93,7 @@ pub trait Trie {
     fn get_with<T>(&self, key: &[u8], query: &Query<T>) -> Result<Option<T>>;
 }
 
-/// A key-value datastore implemented as a database-backed modified Merkle tree.
+/// A key-value datastore implemented as a database-backed Merkle trie.
 pub trait TrieMut {
     /// Return the root of the trie.
     fn root(&self) -> &H256;