From 8ea4f67e4b6fc3c39b75f439809da3b7d0982b2b Mon Sep 17 00:00:00 2001
From: LFC <990479+MichaelScofield@users.noreply.github.com>
Date: Fri, 30 Aug 2024 11:31:19 +0800
Subject: [PATCH] refactor: reduce a object store "stat" call (#4645)

---
 src/mito2/src/cache/write_cache.rs      | 7 ++-----
 src/mito2/src/worker/handle_manifest.rs | 3 ++-
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/mito2/src/cache/write_cache.rs b/src/mito2/src/cache/write_cache.rs
index a21cbb5f6b..ff856fa4cc 100644
--- a/src/mito2/src/cache/write_cache.rs
+++ b/src/mito2/src/cache/write_cache.rs
@@ -176,6 +176,7 @@ impl WriteCache {
         index_key: IndexKey,
         remote_path: &str,
         remote_store: &ObjectStore,
+        file_size: u64,
     ) -> Result<()> {
         const DOWNLOAD_READER_CONCURRENCY: usize = 8;
         const DOWNLOAD_READER_CHUNK_SIZE: ReadableSize = ReadableSize::mb(8);
@@ -188,17 +189,13 @@ impl WriteCache {
             }])
             .start_timer();
 
-        let remote_metadata = remote_store
-            .stat(remote_path)
-            .await
-            .context(error::OpenDalSnafu)?;
         let reader = remote_store
             .reader_with(remote_path)
             .concurrent(DOWNLOAD_READER_CONCURRENCY)
             .chunk(DOWNLOAD_READER_CHUNK_SIZE.as_bytes() as usize)
             .await
             .context(error::OpenDalSnafu)?
-            .into_futures_async_read(0..remote_metadata.content_length())
+            .into_futures_async_read(0..file_size)
             .await
             .context(error::OpenDalSnafu)?;
 
diff --git a/src/mito2/src/worker/handle_manifest.rs b/src/mito2/src/worker/handle_manifest.rs
index b9b20423d2..a7ebb219ce 100644
--- a/src/mito2/src/worker/handle_manifest.rs
+++ b/src/mito2/src/worker/handle_manifest.rs
@@ -306,9 +306,10 @@ async fn edit_region(
 
             let index_key = IndexKey::new(region_id, file_meta.file_id, FileType::Parquet);
             let remote_path = location::sst_file_path(layer.region_dir(), file_meta.file_id);
+            let file_size = file_meta.file_size;
             common_runtime::spawn_global(async move {
                 if write_cache
-                    .download(index_key, &remote_path, layer.object_store())
+                    .download(index_key, &remote_path, layer.object_store(), file_size)
                     .await
                     .is_ok()
                 {