From 3aa689d69845ec52a4459463d9fc6daf3d910bf4 Mon Sep 17 00:00:00 2001
From: Croxx <mrcroxx@outlook.com>
Date: Wed, 10 Apr 2024 15:09:49 +0800
Subject: [PATCH] refactor: remove unstable feature let_chains and lint_reasons
 (#315)

Signed-off-by: MrCroxx <mrcroxx@outlook.com>
---
 foyer-common/src/code.rs                |  6 ++++--
 foyer-common/src/lib.rs                 |  1 -
 foyer-experimental/src/lib.rs           |  1 -
 foyer-intrusive/src/lib.rs              |  4 ++--
 foyer-memory/src/eviction/s3fifo.rs     | 12 ++++++------
 foyer-memory/src/eviction/test_utils.rs |  3 ++-
 foyer-memory/src/generic.rs             | 18 ++++++++++++------
 foyer-memory/src/lib.rs                 |  3 ---
 foyer-storage-bench/src/main.rs         | 23 +++++++++++------------
 foyer-storage/src/admission/mod.rs      |  3 +--
 foyer-storage/src/buffer.rs             |  3 ++-
 foyer-storage/src/catalog.rs            | 22 ++++++++++++----------
 foyer-storage/src/generic.rs            |  6 ++++--
 foyer-storage/src/lib.rs                |  2 --
 foyer-storage/src/region.rs             |  9 ++++++---
 foyer-storage/src/reinsertion/mod.rs    |  3 +--
 foyer-storage/src/test_utils.rs         |  9 ++++++++-
 foyer-storage/tests/storage_test.rs     |  4 ++--
 18 files changed, 73 insertions(+), 59 deletions(-)

diff --git a/foyer-common/src/code.rs b/foyer-common/src/code.rs
index 3e5c3ba3..dda8e00a 100644
--- a/foyer-common/src/code.rs
+++ b/foyer-common/src/code.rs
@@ -95,7 +95,8 @@ pub trait Cursor<T>: Send + Sync + 'static + std::io::Read + std::fmt::Debug {
 /// [`Key`] is required to implement [`Clone`].
 ///
 /// If cloning a [`Key`] is expensive, wrap it with [`Arc`].
-#[expect(unused_variables)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#[allow(unused_variables)]
 pub trait Key:
     Sized + Send + Sync + 'static + std::hash::Hash + Eq + PartialEq + Ord + PartialOrd + std::fmt::Debug + Clone
 {
@@ -122,7 +123,8 @@ pub trait Key:
 /// [`Value`] is required to implement [`Clone`].
 ///
 /// If cloning a [`Value`] is expensive, wrap it with [`Arc`].
-#[expect(unused_variables)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#[allow(unused_variables)]
 pub trait Value: Sized + Send + Sync + 'static + std::fmt::Debug + Clone {
     type Cursor: Cursor<Self> = UnimplementedCursor<Self>;
 
diff --git a/foyer-common/src/lib.rs b/foyer-common/src/lib.rs
index 1681a227..a9541ec9 100644
--- a/foyer-common/src/lib.rs
+++ b/foyer-common/src/lib.rs
@@ -13,7 +13,6 @@
 //  limitations under the License.
 
 #![feature(trait_alias)]
-#![feature(lint_reasons)]
 #![feature(bound_map)]
 #![feature(associated_type_defaults)]
 #![feature(cfg_match)]
diff --git a/foyer-experimental/src/lib.rs b/foyer-experimental/src/lib.rs
index 1d8ca5e2..ec80631e 100644
--- a/foyer-experimental/src/lib.rs
+++ b/foyer-experimental/src/lib.rs
@@ -13,7 +13,6 @@
 //  limitations under the License.
 
 #![feature(cfg_match)]
-#![feature(lint_reasons)]
 #![feature(error_generic_member_access)]
 #![feature(lazy_cell)]
 
diff --git a/foyer-intrusive/src/lib.rs b/foyer-intrusive/src/lib.rs
index 074ed6ba..6d6fbc28 100644
--- a/foyer-intrusive/src/lib.rs
+++ b/foyer-intrusive/src/lib.rs
@@ -14,9 +14,9 @@
 
 #![feature(ptr_metadata)]
 #![feature(trait_alias)]
-#![feature(lint_reasons)]
 #![feature(offset_of)]
-#![expect(clippy::new_without_default)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#![allow(clippy::new_without_default)]
 
 pub use memoffset::offset_of;
 
diff --git a/foyer-memory/src/eviction/s3fifo.rs b/foyer-memory/src/eviction/s3fifo.rs
index c9f54e8a..e8911494 100644
--- a/foyer-memory/src/eviction/s3fifo.rs
+++ b/foyer-memory/src/eviction/s3fifo.rs
@@ -146,13 +146,13 @@ where
     V: Value,
 {
     unsafe fn evict(&mut self) -> Option<NonNull<<S3Fifo<K, V> as Eviction>::Handle>> {
-        if self.small_charges > self.small_capacity
-            && let Some(ptr) = self.evict_small()
-        {
-            Some(ptr)
-        } else {
-            self.evict_main()
+        // TODO(MrCroxx): Use `let_chains` here after it is stable.
+        if self.small_charges > self.small_capacity {
+            if let Some(ptr) = self.evict_small() {
+                return Some(ptr);
+            }
         }
+        self.evict_main()
     }
 
     unsafe fn evict_small(&mut self) -> Option<NonNull<<S3Fifo<K, V> as Eviction>::Handle>> {
diff --git a/foyer-memory/src/eviction/test_utils.rs b/foyer-memory/src/eviction/test_utils.rs
index 39b57347..adf478de 100644
--- a/foyer-memory/src/eviction/test_utils.rs
+++ b/foyer-memory/src/eviction/test_utils.rs
@@ -15,7 +15,8 @@
 use super::Eviction;
 use crate::handle::Handle;
 
-#[expect(clippy::type_complexity)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#[allow(clippy::type_complexity)]
 pub trait TestEviction: Eviction {
     fn dump(&self) -> Vec<(<Self::Handle as Handle>::Key, <Self::Handle as Handle>::Value)>;
 }
diff --git a/foyer-memory/src/generic.rs b/foyer-memory/src/generic.rs
index 6352c368..5ac43267 100644
--- a/foyer-memory/src/generic.rs
+++ b/foyer-memory/src/generic.rs
@@ -43,7 +43,8 @@ struct CacheSharedState<T, L> {
     listener: L,
 }
 
-#[expect(clippy::type_complexity)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#[allow(clippy::type_complexity)]
 struct CacheShard<K, V, H, E, I, L, S>
 where
     K: Key,
@@ -198,9 +199,12 @@ where
     }
 
     unsafe fn evict(&mut self, charge: usize, last_reference_entries: &mut Vec<(K, V, H::Context, usize)>) {
-        while self.usage.load(Ordering::Relaxed) + charge > self.capacity
-            && let Some(evicted) = self.eviction.pop()
-        {
+        // TODO(MrCroxx): Use `let_chains` here after it is stable.
+        while self.usage.load(Ordering::Relaxed) + charge > self.capacity {
+            let evicted = match self.eviction.pop() {
+                Some(evicted) => evicted,
+                None => break,
+            };
             self.state.metrics.evict.fetch_add(1, Ordering::Relaxed);
             let base = evicted.as_ref().base();
             debug_assert!(base.is_in_indexer());
@@ -304,7 +308,8 @@ where
     pub event_listener: L,
 }
 
-#[expect(clippy::type_complexity)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#[allow(clippy::type_complexity)]
 pub enum GenericEntry<K, V, H, E, I, L, S, ER>
 where
     K: Key,
@@ -364,7 +369,8 @@ where
     }
 }
 
-#[expect(clippy::type_complexity)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#[allow(clippy::type_complexity)]
 pub struct GenericCache<K, V, H, E, I, L, S = RandomState>
 where
     K: Key,
diff --git a/foyer-memory/src/lib.rs b/foyer-memory/src/lib.rs
index aa073eb3..3b92ad5a 100644
--- a/foyer-memory/src/lib.rs
+++ b/foyer-memory/src/lib.rs
@@ -12,9 +12,6 @@
 //  See the License for the specific language governing permissions and
 //  limitations under the License.
 
-#![feature(let_chains)]
-#![feature(lint_reasons)]
-
 //! This crate provides a concurrent in-memory cache component that supports replaceable eviction algorithm.
 //!
 //! # Motivation
diff --git a/foyer-storage-bench/src/main.rs b/foyer-storage-bench/src/main.rs
index c2efeb34..acd59aab 100644
--- a/foyer-storage-bench/src/main.rs
+++ b/foyer-storage-bench/src/main.rs
@@ -12,9 +12,6 @@
 //  See the License for the specific language governing permissions and
 //  limitations under the License.
 
-#![feature(let_chains)]
-#![feature(lint_reasons)]
-
 mod analyze;
 mod export;
 mod rate;
@@ -754,13 +751,14 @@ async fn write(
         }
 
         let idx = id + step * c;
-        // TODO(MrCroxx): Use random content?
         let entry_size = OsRng.gen_range(context.entry_size_range.clone());
         let data = Arc::new(text(idx as usize, entry_size));
-        if let Some(limiter) = &mut limiter
-            && let Some(wait) = limiter.consume(entry_size as f64)
-        {
-            tokio::time::sleep(wait).await;
+
+        // TODO(MrCroxx): Use `let_chains` here after it is stable.
+        if let Some(limiter) = &mut limiter {
+            if let Some(wait) = limiter.consume(entry_size as f64) {
+                tokio::time::sleep(wait).await;
+            }
         }
 
         let time = Instant::now();
@@ -849,10 +847,11 @@ async fn read(
             }
             context.metrics.get_bytes.fetch_add(entry_size, Ordering::Relaxed);
 
-            if let Some(limiter) = &mut limiter
-                && let Some(wait) = limiter.consume(entry_size as f64)
-            {
-                tokio::time::sleep(wait).await;
+            // TODO(MrCroxx): Use `let_chains` here after it is stable.
+            if let Some(limiter) = &mut limiter {
+                if let Some(wait) = limiter.consume(entry_size as f64) {
+                    tokio::time::sleep(wait).await;
+                }
             }
         } else {
             if let Err(e) = context.metrics.get_miss_lats.write().record(lat) {
diff --git a/foyer-storage/src/admission/mod.rs b/foyer-storage/src/admission/mod.rs
index dcff9e98..406ed732 100644
--- a/foyer-storage/src/admission/mod.rs
+++ b/foyer-storage/src/admission/mod.rs
@@ -41,12 +41,11 @@ where
     }
 }
 
-#[expect(unused_variables)]
 pub trait AdmissionPolicy: Send + Sync + 'static + Debug {
     type Key: Key;
     type Value: Value;
 
-    fn init(&self, context: AdmissionContext<Self::Key, Self::Value>) {}
+    fn init(&self, context: AdmissionContext<Self::Key, Self::Value>);
 
     fn judge(&self, key: &Self::Key, weight: usize) -> bool;
 
diff --git a/foyer-storage/src/buffer.rs b/foyer-storage/src/buffer.rs
index dfc0c179..8090ef7e 100644
--- a/foyer-storage/src/buffer.rs
+++ b/foyer-storage/src/buffer.rs
@@ -179,7 +179,8 @@ where
     /// # Format
     ///
     /// | header | value (compressed) | key | <padding> |
-    #[expect(clippy::uninit_vec)]
+    // TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+    #[allow(clippy::uninit_vec)]
     pub async fn write(
         &mut self,
         Entry {
diff --git a/foyer-storage/src/catalog.rs b/foyer-storage/src/catalog.rs
index 3177995b..bbc9c749 100644
--- a/foyer-storage/src/catalog.rs
+++ b/foyer-storage/src/catalog.rs
@@ -130,12 +130,13 @@ where
             item.inserted = Some(Instant::now());
             guard.insert(key.clone(), item)
         };
-        if let Some(old) = old
-            && let Index::Inflight { .. } = old.index()
-        {
-            self.metrics
-                .inner_op_duration_entry_flush
-                .observe(old.inserted.unwrap().elapsed().as_secs_f64());
+        // TODO(MrCroxx): Use `let_chains` here after it is stable.
+        if let Some(old) = old {
+            if let Index::Inflight { .. } = old.index() {
+                self.metrics
+                    .inner_op_duration_entry_flush
+                    .observe(old.inserted.unwrap().elapsed().as_secs_f64());
+            }
         }
     }
 
@@ -147,10 +148,11 @@ where
     pub fn remove(&self, key: &K) -> Option<Item<K, V>> {
         let shard = self.shard(key);
         let info: Option<Item<K, V>> = self.items[shard].write().remove(key);
-        if let Some(info) = &info
-            && let Index::Region { view } = &info.index
-        {
-            self.regions[*view.id() as usize].lock().remove(key);
+        // TODO(MrCroxx): Use `let_chains` here after it is stable.
+        if let Some(info) = &info {
+            if let Index::Region { view } = &info.index {
+                self.regions[*view.id() as usize].lock().remove(key);
+            }
         }
         info
     }
diff --git a/foyer-storage/src/generic.rs b/foyer-storage/src/generic.rs
index 490c3915..51522814 100644
--- a/foyer-storage/src/generic.rs
+++ b/foyer-storage/src/generic.rs
@@ -236,7 +236,8 @@ where
 
         let (flushers_stop_tx, _) = broadcast::channel(DEFAULT_BROADCAST_CAPACITY);
         let flusher_stop_rxs = (0..config.flushers).map(|_| flushers_stop_tx.subscribe()).collect_vec();
-        #[expect(clippy::type_complexity)]
+        // TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+        #[allow(clippy::type_complexity)]
         let (flusher_entry_txs, flusher_entry_rxs): (
             Vec<mpsc::UnboundedSender<Entry<K, V>>>,
             Vec<mpsc::UnboundedReceiver<Entry<K, V>>>,
@@ -1081,7 +1082,8 @@ mod tests {
     type TestStoreConfig = GenericStoreConfig<u64, Vec<u8>, FsDevice, Fifo<RegionEpItemAdapter<FifoLink>>>;
 
     #[tokio::test]
-    #[expect(clippy::identity_op)]
+    // TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+    #[allow(clippy::identity_op)]
     async fn test_recovery() {
         const KB: usize = 1024;
         const MB: usize = 1024 * 1024;
diff --git a/foyer-storage/src/lib.rs b/foyer-storage/src/lib.rs
index 2799f01b..7e2cf9a1 100644
--- a/foyer-storage/src/lib.rs
+++ b/foyer-storage/src/lib.rs
@@ -16,10 +16,8 @@
 #![feature(strict_provenance)]
 #![feature(trait_alias)]
 #![feature(get_mut_unchecked)]
-#![feature(let_chains)]
 #![feature(error_generic_member_access)]
 #![feature(lazy_cell)]
-#![feature(lint_reasons)]
 #![feature(box_into_inner)]
 #![feature(try_trait_v2)]
 #![feature(offset_of)]
diff --git a/foyer-storage/src/region.rs b/foyer-storage/src/region.rs
index 94a7dc37..4280d395 100644
--- a/foyer-storage/src/region.rs
+++ b/foyer-storage/src/region.rs
@@ -105,7 +105,8 @@ pub struct RegionInner<A>
 where
     A: BufferAllocator,
 {
-    #[expect(clippy::type_complexity)]
+    // TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+    #[allow(clippy::type_complexity)]
     waits: BTreeMap<(usize, usize), Vec<oneshot::Sender<Result<Arc<Vec<u8, A>>>>>>,
 }
 
@@ -152,7 +153,8 @@ where
     }
 
     /// Load region data by view from device.
-    #[expect(clippy::type_complexity)]
+    // TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+    #[allow(clippy::type_complexity)]
     #[tracing::instrument(skip(self, view))]
     pub async fn load(&self, view: RegionView) -> Result<Option<Arc<Vec<u8, D::IoBufferAllocator>>>> {
         let res = self
@@ -164,7 +166,8 @@ where
     }
 
     /// Load region data with given `range` from device.
-    #[expect(clippy::type_complexity)]
+    // TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+    #[allow(clippy::type_complexity)]
     #[tracing::instrument(skip(self, range), fields(start, end))]
     pub async fn load_range(
         &self,
diff --git a/foyer-storage/src/reinsertion/mod.rs b/foyer-storage/src/reinsertion/mod.rs
index 493c941f..7681863e 100644
--- a/foyer-storage/src/reinsertion/mod.rs
+++ b/foyer-storage/src/reinsertion/mod.rs
@@ -41,12 +41,11 @@ where
     }
 }
 
-#[expect(unused_variables)]
 pub trait ReinsertionPolicy: Send + Sync + 'static + Debug {
     type Key: Key;
     type Value: Value;
 
-    fn init(&self, context: ReinsertionContext<Self::Key, Self::Value>) {}
+    fn init(&self, context: ReinsertionContext<Self::Key, Self::Value>);
 
     fn judge(&self, key: &Self::Key, weight: usize) -> bool;
 
diff --git a/foyer-storage/src/test_utils.rs b/foyer-storage/src/test_utils.rs
index 25fffc85..1c155ca0 100644
--- a/foyer-storage/src/test_utils.rs
+++ b/foyer-storage/src/test_utils.rs
@@ -17,7 +17,10 @@ use std::{collections::HashSet, marker::PhantomData};
 use foyer_common::code::{Key, Value};
 use parking_lot::Mutex;
 
-use crate::{admission::AdmissionPolicy, reinsertion::ReinsertionPolicy};
+use crate::{
+    admission::{AdmissionContext, AdmissionPolicy},
+    reinsertion::{ReinsertionContext, ReinsertionPolicy},
+};
 
 #[derive(Debug, Clone)]
 pub enum Record<K: Key> {
@@ -83,6 +86,8 @@ where
 
     type Value = V;
 
+    fn init(&self, _: AdmissionContext<Self::Key, Self::Value>) {}
+
     fn judge(&self, key: &K, _weight: usize) -> bool {
         self.records.lock().push(Record::Admit(key.clone()));
         true
@@ -102,6 +107,8 @@ where
 
     type Value = V;
 
+    fn init(&self, _: ReinsertionContext<Self::Key, Self::Value>) {}
+
     fn judge(&self, key: &K, _weight: usize) -> bool {
         self.records.lock().push(Record::Evict(key.clone()));
         false
diff --git a/foyer-storage/tests/storage_test.rs b/foyer-storage/tests/storage_test.rs
index 97bc7143..3910f881 100644
--- a/foyer-storage/tests/storage_test.rs
+++ b/foyer-storage/tests/storage_test.rs
@@ -12,8 +12,8 @@
 //  See the License for the specific language governing permissions and
 //  limitations under the License.
 
-#![feature(lint_reasons)]
-#![expect(clippy::identity_op)]
+// TODO(MrCroxx): use `expect` after `lint_reasons` is stable.
+#![allow(clippy::identity_op)]
 
 use std::{path::PathBuf, sync::Arc, time::Duration};