Default enable raft-engine (#150)

etc/config-template.toml

@@ -949,7 +949,7 @@
 [raft-engine]
 ## Determines whether to use Raft Engine to store raft logs. When it is
 ## enabled, configurations of `raftdb` are ignored.
-# enable = false
+# enable = true
 
 ## The directory at which raft log files are stored. If the directory does not
 ## exist, it will be created when TiKV is started.

src/config.rs

@@ -1409,14 +1409,23 @@ impl RaftDbConfig {
     }
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, PartialEq, Default)]
+#[derive(Clone, Serialize, Deserialize, Debug, PartialEq)]
 #[serde(default, rename_all = "kebab-case")]
 pub struct RaftEngineConfig {
     pub enable: bool,
     #[serde(flatten)]
     config: RawRaftEngineConfig,
 }
 
+impl Default for RaftEngineConfig {
+    fn default() -> Self {
+        Self {
+            enable: true,
+            config: RawRaftEngineConfig::default(),
+        }
+    }
+}
+
 impl RaftEngineConfig {
     fn validate(&mut self) -> Result<(), Box<dyn Error>> {
         self.config.sanitize().map_err(Box::new)?;