feat: implement region migration manager

src/common/meta/src/key/table_route.rs

@@ -87,6 +87,11 @@ impl TableRouteValue {
             .cloned()
     }
 
+    /// Returns true if it's [TableRouteValue::Physical].
+    pub fn is_physical(&self) -> bool {
+        matches!(self, TableRouteValue::Physical(_))
+    }
+
     /// Gets the [RegionRoute]s of this [TableRouteValue::Physical].
     ///
     /// # Panics

src/meta-srv/src/error.rs

@@ -32,6 +32,12 @@ use crate::pubsub::Message;
 #[snafu(visibility(pub))]
 #[stack_trace_debug]
 pub enum Error {
+    #[snafu(display("Another migration procedure is running for region: {}", region_id,))]
+    MigrationRunning {
+        location: Location,
+        region_id: RegionId,
+    },
+
     #[snafu(display("The region migration procedure aborted, reason: {}", reason))]
     MigrationAbort { location: Location, reason: String },
 
@@ -675,7 +681,8 @@ impl ErrorExt for Error {
             | Error::TableIdChanged { .. }
             | Error::RegionOpeningRace { .. }
             | Error::RegionRouteNotFound { .. }
-            | Error::MigrationAbort { .. } => StatusCode::Unexpected,
+            | Error::MigrationAbort { .. }
+            | Error::MigrationRunning { .. } => StatusCode::Unexpected,
             Error::TableNotFound { .. } => StatusCode::TableNotFound,
             Error::InvalidateTableCache { source, .. } => source.status_code(),
             Error::RequestDatanode { source, .. } => source.status_code(),

src/meta-srv/src/procedure/region_migration.rs

@@ -13,6 +13,9 @@
 // limitations under the License.
 
 pub(crate) mod downgrade_leader_region;
+// TODO(weny): remove it.
+#[allow(dead_code)]
+pub(crate) mod manager;
 pub(crate) mod migration_abort;
 pub(crate) mod migration_end;
 pub(crate) mod migration_start;
@@ -123,6 +126,7 @@ pub trait ContextFactory {
 }
 
 /// Default implementation.
+#[derive(Clone)]
 pub struct ContextFactoryImpl {
     volatile_ctx: VolatileContext,
     table_metadata_manager: TableMetadataManagerRef,