From 20ce7d428d23f573c3364ebd4596b3e3794de549 Mon Sep 17 00:00:00 2001
From: Weny Xu <wenymedia@gmail.com>
Date: Mon, 27 May 2024 16:56:46 +0900
Subject: [PATCH] fix(metric-engine): missing catchup implementation (#4048)

* fix(metric-engine): missing catchup implementation

* fix: should be `metadata_region_id`
---
 src/metric-engine/src/engine.rs         |  4 +-
 src/metric-engine/src/engine/catchup.rs | 61 +++++++++++++++++++++++++
 src/metric-engine/src/error.rs          | 10 +++-
 src/store-api/src/region_request.rs     |  2 +-
 4 files changed, 73 insertions(+), 4 deletions(-)
 create mode 100644 src/metric-engine/src/engine/catchup.rs

diff --git a/src/metric-engine/src/engine.rs b/src/metric-engine/src/engine.rs
index 20c7e0d050ae..38cbc6e4ac4e 100644
--- a/src/metric-engine/src/engine.rs
+++ b/src/metric-engine/src/engine.rs
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 mod alter;
+mod catchup;
 mod close;
 mod create;
 mod drop;
@@ -147,8 +148,7 @@ impl RegionEngine for MetricEngine {
             | RegionRequest::Flush(_)
             | RegionRequest::Compact(_)
             | RegionRequest::Truncate(_) => UnsupportedRegionRequestSnafu { request }.fail(),
-            // It always Ok(0), all data is the latest.
-            RegionRequest::Catchup(_) => Ok(0),
+            RegionRequest::Catchup(ref req) => self.inner.catchup_region(region_id, *req).await,
         };
 
         result.map_err(BoxedError::new).map(|rows| RegionResponse {
diff --git a/src/metric-engine/src/engine/catchup.rs b/src/metric-engine/src/engine/catchup.rs
new file mode 100644
index 000000000000..0e6aee1e3883
--- /dev/null
+++ b/src/metric-engine/src/engine/catchup.rs
@@ -0,0 +1,61 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use snafu::ResultExt;
+use store_api::region_engine::RegionEngine;
+use store_api::region_request::{AffectedRows, RegionCatchupRequest, RegionRequest};
+use store_api::storage::RegionId;
+
+use crate::engine::MetricEngineInner;
+use crate::error::{MitoCatchupOperationSnafu, Result, UnsupportedRegionRequestSnafu};
+use crate::utils;
+
+impl MetricEngineInner {
+    pub async fn catchup_region(
+        &self,
+        region_id: RegionId,
+        req: RegionCatchupRequest,
+    ) -> Result<AffectedRows> {
+        if !self.is_physical_region(region_id) {
+            return UnsupportedRegionRequestSnafu {
+                request: RegionRequest::Catchup(req),
+            }
+            .fail();
+        }
+        let metadata_region_id = utils::to_metadata_region_id(region_id);
+        // TODO(weny): improve the catchup, we can read the wal entries only once.
+        self.mito
+            .handle_request(
+                metadata_region_id,
+                RegionRequest::Catchup(RegionCatchupRequest {
+                    set_writable: req.set_writable,
+                    entry_id: None,
+                }),
+            )
+            .await
+            .context(MitoCatchupOperationSnafu)?;
+
+        self.mito
+            .handle_request(
+                region_id,
+                RegionRequest::Catchup(RegionCatchupRequest {
+                    set_writable: req.set_writable,
+                    entry_id: req.entry_id,
+                }),
+            )
+            .await
+            .context(MitoCatchupOperationSnafu)
+            .map(|response| response.affected_rows)
+    }
+}
diff --git a/src/metric-engine/src/error.rs b/src/metric-engine/src/error.rs
index f52bc6e3cc72..340f4f19bcfa 100644
--- a/src/metric-engine/src/error.rs
+++ b/src/metric-engine/src/error.rs
@@ -121,6 +121,13 @@ pub enum Error {
         location: Location,
     },
 
+    #[snafu(display("Mito catchup operation fails"))]
+    MitoCatchupOperation {
+        source: BoxedError,
+        #[snafu(implicit)]
+        location: Location,
+    },
+
     #[snafu(display("Failed to collect record batch stream"))]
     CollectRecordBatchStream {
         source: common_recordbatch::error::Error,
@@ -267,7 +274,8 @@ impl ErrorExt for Error {
             | OpenMitoRegion { source, .. }
             | CloseMitoRegion { source, .. }
             | MitoReadOperation { source, .. }
-            | MitoWriteOperation { source, .. } => source.status_code(),
+            | MitoWriteOperation { source, .. }
+            | MitoCatchupOperation { source, .. } => source.status_code(),
 
             CollectRecordBatchStream { source, .. } => source.status_code(),
 
diff --git a/src/store-api/src/region_request.rs b/src/store-api/src/region_request.rs
index 70271f017b35..1452fcbe6125 100644
--- a/src/store-api/src/region_request.rs
+++ b/src/store-api/src/region_request.rs
@@ -666,7 +666,7 @@ pub struct RegionTruncateRequest {}
 ///
 /// Makes a readonly region to catch up to leader region changes.
 /// There is no effect if it operating on a leader region.
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 pub struct RegionCatchupRequest {
     /// Sets it to writable if it's available after it has caught up with all changes.
     pub set_writable: bool,