From 29cbacf0f6150a22fd49fc77afc1b63513a74c75 Mon Sep 17 00:00:00 2001
From: niebayes <niebayes@gmail.com>
Date: Fri, 15 Dec 2023 17:28:58 +0800
Subject: [PATCH] chore: add some comments to kafka

---
 src/common/meta/src/wal/kafka.rs       | 6 +++++-
 src/common/meta/src/wal/kafka/topic.rs | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/common/meta/src/wal/kafka.rs b/src/common/meta/src/wal/kafka.rs
index 0ec523cfc346..c835512051f2 100644
--- a/src/common/meta/src/wal/kafka.rs
+++ b/src/common/meta/src/wal/kafka.rs
@@ -20,10 +20,14 @@ use serde::{Deserialize, Serialize};
 
 use crate::wal::kafka::topic::Topic;
 
+/// Configurations for bootstraping a kafka wal.
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Default)]
 pub struct KafkaConfig;
 
+/// Kafka wal options allocated to a region.
 #[derive(Serialize, Deserialize, Default, Debug, Clone, PartialEq)]
 pub struct KafkaWalOptions {
-    topic: Topic,
+    /// Kafka wal topic.
+    /// Publishers publish log entries to the topic while subscribers pull log entries from the topic.
+    pub topic: Topic,
 }
diff --git a/src/common/meta/src/wal/kafka/topic.rs b/src/common/meta/src/wal/kafka/topic.rs
index 1f2c1a466b41..755e7e2ba5a3 100644
--- a/src/common/meta/src/wal/kafka/topic.rs
+++ b/src/common/meta/src/wal/kafka/topic.rs
@@ -12,4 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+/// Kafka wal topic.
+// A topic is simply a string right now. But it may be more complex in the future.
 pub type Topic = String;