From f3b68253c2d5c61f696379e65721cb0980131a25 Mon Sep 17 00:00:00 2001
From: "Lei, HUANG" <6406592+v0y4g3r@users.noreply.github.com>
Date: Mon, 6 May 2024 18:26:40 +0800
Subject: [PATCH] chore: remove one slice copy in wal encoding (#3861)

* chore: remove one slice copy in wal encoding

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

* fix: cr comments

---------

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>
---
 src/log-store/src/kafka/log_store.rs       | 9 ++-------
 src/log-store/src/noop.rs                  | 9 ++-------
 src/log-store/src/raft_engine/log_store.rs | 9 ++-------
 src/mito2/src/wal.rs                       | 4 ++--
 src/store-api/src/logstore.rs              | 3 +--
 5 files changed, 9 insertions(+), 25 deletions(-)

diff --git a/src/log-store/src/kafka/log_store.rs b/src/log-store/src/kafka/log_store.rs
index 14f7ba8df1bb..1a0f96b6587b 100644
--- a/src/log-store/src/kafka/log_store.rs
+++ b/src/log-store/src/kafka/log_store.rs
@@ -59,14 +59,9 @@ impl LogStore for KafkaLogStore {
     type Namespace = NamespaceImpl;
 
     /// Creates an entry of the associated Entry type.
-    fn entry<D: AsRef<[u8]>>(
-        &self,
-        data: D,
-        entry_id: EntryId,
-        ns: Self::Namespace,
-    ) -> Self::Entry {
+    fn entry(&self, data: &mut Vec<u8>, entry_id: EntryId, ns: Self::Namespace) -> Self::Entry {
         EntryImpl {
-            data: data.as_ref().to_vec(),
+            data: std::mem::take(data),
             id: entry_id,
             ns,
         }
diff --git a/src/log-store/src/noop.rs b/src/log-store/src/noop.rs
index 48668c39ec04..1d28e67dce16 100644
--- a/src/log-store/src/noop.rs
+++ b/src/log-store/src/noop.rs
@@ -97,12 +97,7 @@ impl LogStore for NoopLogStore {
         Ok(vec![])
     }
 
-    fn entry<D: AsRef<[u8]>>(
-        &self,
-        data: D,
-        entry_id: EntryId,
-        ns: Self::Namespace,
-    ) -> Self::Entry {
+    fn entry(&self, data: &mut Vec<u8>, entry_id: EntryId, ns: Self::Namespace) -> Self::Entry {
         let _ = data;
         let _ = entry_id;
         let _ = ns;
@@ -140,7 +135,7 @@ mod tests {
     #[tokio::test]
     async fn test_noop_logstore() {
         let store = NoopLogStore;
-        let e = store.entry("".as_bytes(), 1, NamespaceImpl);
+        let e = store.entry(&mut vec![], 1, NamespaceImpl);
         let _ = store.append(e.clone()).await.unwrap();
         assert!(store.append_batch(vec![e]).await.is_ok());
         store.create_namespace(&NamespaceImpl).await.unwrap();
diff --git a/src/log-store/src/raft_engine/log_store.rs b/src/log-store/src/raft_engine/log_store.rs
index f5fab5f97eed..b2070abbf3ec 100644
--- a/src/log-store/src/raft_engine/log_store.rs
+++ b/src/log-store/src/raft_engine/log_store.rs
@@ -402,15 +402,10 @@ impl LogStore for RaftEngineLogStore {
         Ok(namespaces)
     }
 
-    fn entry<D: AsRef<[u8]>>(
-        &self,
-        data: D,
-        entry_id: EntryId,
-        ns: Self::Namespace,
-    ) -> Self::Entry {
+    fn entry(&self, data: &mut Vec<u8>, entry_id: EntryId, ns: Self::Namespace) -> Self::Entry {
         EntryImpl {
             id: entry_id,
-            data: data.as_ref().to_vec(),
+            data: std::mem::take(data),
             namespace_id: ns.id(),
             ..Default::default()
         }
diff --git a/src/mito2/src/wal.rs b/src/mito2/src/wal.rs
index 49b6dd493148..06e38f36f98f 100644
--- a/src/mito2/src/wal.rs
+++ b/src/mito2/src/wal.rs
@@ -135,7 +135,7 @@ pub struct WalWriter<S: LogStore> {
 }
 
 impl<S: LogStore> WalWriter<S> {
-    /// Add an wal entry for specific region to the writer's buffer.
+    /// Add a wal entry for specific region to the writer's buffer.
     pub fn add_entry(
         &mut self,
         region_id: RegionId,
@@ -157,7 +157,7 @@ impl<S: LogStore> WalWriter<S> {
             .context(EncodeWalSnafu { region_id })?;
         let entry = self
             .store
-            .entry(&self.entry_encode_buf, entry_id, namespace);
+            .entry(&mut self.entry_encode_buf, entry_id, namespace);
 
         self.entries.push(entry);
 
diff --git a/src/store-api/src/logstore.rs b/src/store-api/src/logstore.rs
index d6ebcb2573c2..33739ac85fb4 100644
--- a/src/store-api/src/logstore.rs
+++ b/src/store-api/src/logstore.rs
@@ -72,8 +72,7 @@ pub trait LogStore: Send + Sync + 'static + std::fmt::Debug {
     async fn obsolete(&self, ns: Self::Namespace, entry_id: EntryId) -> Result<(), Self::Error>;
 
     /// Makes an entry instance of the associated Entry type
-    fn entry<D: AsRef<[u8]>>(&self, data: D, entry_id: EntryId, ns: Self::Namespace)
-        -> Self::Entry;
+    fn entry(&self, data: &mut Vec<u8>, entry_id: EntryId, ns: Self::Namespace) -> Self::Entry;
 
     /// Makes a namespace instance of the associated Namespace type
     fn namespace(&self, ns_id: NamespaceId, wal_options: &WalOptions) -> Self::Namespace;