squash!: update comments

Signed-off-by: bsbds <69835502+bsbds@users.noreply.github.com>

crates/curp/src/server/storage/wal/pipeline.rs

@@ -10,11 +10,7 @@ use std::{
 
 use clippy_utilities::OverflowArithmetic;
 use event_listener::Event;
-use flume::r#async::RecvStream;
-use futures::{FutureExt, StreamExt};
 use thiserror::Error;
-use tokio::task::JoinHandle;
-use tokio_stream::Stream;
 use tracing::error;
 
 use super::util::LockedFile;
@@ -28,8 +24,11 @@ pub(super) struct FilePipeline {
     dir: PathBuf,
     /// The size of the temp file
     file_size: u64,
-    /// The file receive stream
-    file_stream: flume::IntoIter<LockedFile>,
+    /// The file receive iterator
+    ///
+    /// As tokio::fs is generally slower than std::fs, we use synchronous file allocation.
+    /// Please also refer to the issue discussed on the tokio repo: https://github.com/tokio-rs/tokio/issues/3664
+    file_iter: flume::IntoIter<LockedFile>,
     /// Stopped flag
     stopped: Arc<AtomicBool>,
 }
@@ -97,7 +96,7 @@ impl FilePipeline {
         Ok(Self {
             dir,
             file_size,
-            file_stream: file_rx.into_iter(),
+            file_iter: file_rx.into_iter(),
             stopped,
         })
     }
@@ -143,7 +142,7 @@ impl Iterator for FilePipeline {
         if self.stopped.load(Ordering::Relaxed) {
             return None;
         }
-        self.file_stream.next().map(Ok)
+        self.file_iter.next().map(Ok)
     }
 }