Remove excessive use of "Default".

durio/src/persister.rs

@@ -21,12 +21,6 @@ impl Persister {
     }
 }
 
-impl Default for Persister {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 impl ruaft::Persister for Persister {
     fn read_state(&self) -> bytes::Bytes {
         self.state.lock().bytes.clone()

kvraft/src/async_client.rs

@@ -23,7 +23,7 @@ impl AsyncClerk {
 
     pub async fn get<K: AsRef<str>>(&self, key: K) -> Option<String> {
         self.inner
-            .get(key.as_ref().to_owned(), Default::default())
+            .get(key.as_ref().to_owned(), KVRaftOptions::default())
             .await
             .expect("Get should never return error with unlimited retry.")
     }
@@ -32,7 +32,7 @@ impl AsyncClerk {
         let key = key.as_ref();
         let value = value.as_ref();
         self.inner
-            .put(key.to_owned(), value.to_owned(), Default::default())
+            .put(key.to_owned(), value.to_owned(), KVRaftOptions::default())
             .await
             .expect("Put should never return error with unlimited retry.")
     }
@@ -41,7 +41,7 @@ impl AsyncClerk {
         let key = key.as_ref();
         let value = value.as_ref();
         self.inner
-            .append(key.to_owned(), value.to_owned(), Default::default())
+            .append(key.to_owned(), value.to_owned(), KVRaftOptions::default())
             .await
             .expect("Append should never return error with unlimited retry.")
     }
@@ -318,7 +318,7 @@ mod tests {
         let fake_remote_kvraft0 = FakeRemoteKvraft {
             peer_size: 5,
             id: 0,
-            data: Arc::new(Default::default()),
+            data: Arc::new(Mutex::new(HashMap::new())),
         };
         fake_remote_kvraft0
             .data

kvraft/src/client.rs

@@ -28,7 +28,7 @@ impl Clerk {
 
         let key = key.as_ref();
         inner
-            .get(key.to_owned(), Default::default())
+            .get(key.to_owned(), KVRaftOptions::default())
             .expect("Get should never return error with unlimited retry.")
     }
 
@@ -38,7 +38,7 @@ impl Clerk {
         let key = key.as_ref();
         let value = value.as_ref();
         inner
-            .put(key.to_owned(), value.to_owned(), Default::default())
+            .put(key.to_owned(), value.to_owned(), KVRaftOptions::default())
             .expect("Put should never return error with unlimited retry.")
     }
 
@@ -48,7 +48,7 @@ impl Clerk {
         let key = key.as_ref();
         let value = value.as_ref();
         inner
-            .append(key.to_owned(), value.to_owned(), Default::default())
+            .append(key.to_owned(), value.to_owned(), KVRaftOptions::default())
             .expect("Append should never return error with unlimited retry.")
     }
 

kvraft/src/server.rs

@@ -124,7 +124,7 @@ impl KVServer {
         let snapshot_holder_clone = snapshot_holder.clone();
         let ret = Arc::new(Self {
             me,
-            state: Default::default(),
+            state: Mutex::new(KVServerState::default()),
             rf: Raft::new(
                 servers,
                 me,

src/election.rs

@@ -13,7 +13,6 @@ use crate::{
     Peer, Persister, Raft, RaftState, RemoteRaft, RequestVoteArgs, State, Term,
 };
 
-#[derive(Default)]
 pub(crate) struct ElectionState {
     // Timer will be removed upon shutdown or elected.
     timer: Mutex<(usize, Option<Instant>)>,

src/lib.rs

@@ -198,10 +198,10 @@ where
             me: Peer(me),
             persister,
             new_log_entry: None,
-            apply_command_signal: Arc::new(Default::default()),
-            keep_running: Arc::new(Default::default()),
+            apply_command_signal: Default::default(),
+            keep_running: Default::default(),
             election: Arc::new(election),
-            snapshot_daemon: Default::default(),
+            snapshot_daemon: SnapshotDaemon::create(),
             verify_authority_daemon: VerifyAuthorityDaemon::create(peer_size),
             heartbeats_daemon: HeartbeatsDaemon::create(),
             thread_pool: Arc::new(thread_pool),

src/snapshot.rs

@@ -14,7 +14,7 @@ pub struct Snapshot {
     pub data: Vec<u8>,
 }
 
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug)]
 pub(crate) struct SnapshotDaemon {
     unparker: Option<Unparker>,
     current_snapshot: Arc<(Mutex<Snapshot>, Condvar)>,
@@ -25,6 +25,14 @@ pub trait RequestSnapshotFnMut: 'static + Send + FnMut(Index) {}
 impl<T: 'static + Send + FnMut(Index)> RequestSnapshotFnMut for T {}
 
 impl SnapshotDaemon {
+    /// Create a new snapshot daemon.
+    pub fn create() -> Self {
+        Self {
+            unparker: None,
+            current_snapshot: Default::default(),
+        }
+    }
+
     /// Saves the snapshot into the staging area of the daemon, before it is
     /// applied to the log.
     ///

src/verify_authority.rs

@@ -30,7 +30,7 @@ struct VerifyAuthorityToken {
     sender: tokio::sync::oneshot::Sender<VerifyAuthorityResult>,
 }
 
-#[derive(Clone, Copy, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, Ord, PartialOrd, PartialEq)]
 struct QueueIndex(usize);
 
 /// The state of this daemon, should bee protected by a mutex.
@@ -52,7 +52,7 @@ impl VerifyAuthorityState {
     pub fn create(peer_count: usize) -> Self {
         VerifyAuthorityState {
             term: Term(0),
-            queue: Default::default(),
+            queue: VecDeque::new(),
             start: QueueIndex(0),
             covered: vec![QueueIndex(0); peer_count],
         }

test_configs/src/kvraft/generic_test.rs

@@ -105,7 +105,7 @@ fn linearizability_client(
             call_op = KvInput {
                 op: KvOp::Get,
                 key,
-                value: Default::default(),
+                value: String::new(),
             };
             return_op = result;
         }

test_configs/src/persister.rs

@@ -21,12 +21,6 @@ impl Persister {
     }
 }
 
-impl Default for Persister {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 impl ruaft::Persister for Persister {
     fn read_state(&self) -> bytes::Bytes {
         self.state.lock().bytes.clone()