chore(turbo-tasks-backend): Remove ExecuteContextImpl::lower_read_transaction

Author: bgw

turbopack/crates/turbo-tasks-backend/src/backend/operation/mod.rs

@@ -107,10 +107,11 @@ where
         }
     }
 
-    fn transaction<'l>(&'l mut self) -> Option<&'l B::ReadTransaction<'l>>
-    where
-        'e: 'l,
-    {
+    fn restore_task_data(
+        &mut self,
+        task_id: TaskId,
+        category: TaskDataCategory,
+    ) -> Vec<CachedDataItem> {
         if matches!(self.transaction, TransactionState::None) {
             let tx = self.backend.backing_storage.start_read_transaction();
             let tx = tx.map(|tx| {
@@ -119,23 +120,16 @@ where
             });
             self.transaction = TransactionState::Owned(tx);
         }
-        match &self.transaction {
+        let tx = match &self.transaction {
             TransactionState::None => unreachable!(),
-            TransactionState::Borrowed(tx) => tx.map(B::lower_read_transaction),
-            TransactionState::Owned(tx) => tx.as_ref().map(B::lower_read_transaction),
-        }
-    }
-
-    fn restore_task_data(
-        &mut self,
-        task_id: TaskId,
-        category: TaskDataCategory,
-    ) -> Vec<CachedDataItem> {
-        // Safety: `transaction` is a valid transaction from `self.backend.backing_storage`.
+            TransactionState::Borrowed(tx) => *tx,
+            TransactionState::Owned(tx) => tx.as_ref(),
+        };
+        // Safety: `tx` is a valid transaction from `self.backend.backing_storage`.
         let result = unsafe {
             self.backend
                 .backing_storage
-                .lookup_data(self.transaction(), task_id, category)
+                .lookup_data(tx, task_id, category)
         };
         match result {
             Ok(data) => data,

turbopack/crates/turbo-tasks-backend/src/backing_storage.rs

@@ -41,9 +41,6 @@ pub trait BackingStorage: BackingStorageSealed {
 /// [`BackingStorage::invalidate`] method.
 pub trait BackingStorageSealed: 'static + Send + Sync {
     type ReadTransaction<'l>;
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i>;
     fn next_free_task_id(&self) -> Result<TaskId>;
     fn next_session_id(&self) -> Result<SessionId>;
     fn uncompleted_operations(&self) -> Result<Vec<AnyOperation>>;

turbopack/crates/turbo-tasks-backend/src/database/fresh_db_optimization.rs

@@ -37,12 +37,6 @@ impl<T: KeyValueDatabase> KeyValueDatabase for FreshDbOptimization<T> {
     where
         Self: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        T::lower_read_transaction(tx)
-    }
-
     fn is_empty(&self) -> bool {
         self.fresh_db.load(Ordering::Acquire) || self.database.is_empty()
     }

turbopack/crates/turbo-tasks-backend/src/database/key_value_database.rs

@@ -18,10 +18,6 @@ pub trait KeyValueDatabase {
     where
         Self: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i>;
-
     fn begin_read_transaction(&self) -> Result<Self::ReadTransaction<'_>>;
 
     fn is_empty(&self) -> bool {

turbopack/crates/turbo-tasks-backend/src/database/lmdb/mod.rs

@@ -75,12 +75,6 @@ impl KeyValueDatabase for LmbdKeyValueDatabase {
     where
         Self: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        tx
-    }
-
     fn begin_read_transaction(&self) -> Result<Self::ReadTransaction<'_>> {
         Ok(self.env.begin_ro_txn()?)
     }

turbopack/crates/turbo-tasks-backend/src/database/noop_kv.rs

@@ -15,12 +15,6 @@ impl KeyValueDatabase for NoopKvDb {
     where
         Self: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        tx
-    }
-
     fn begin_read_transaction(&self) -> Result<Self::ReadTransaction<'_>> {
         Ok(())
     }

turbopack/crates/turbo-tasks-backend/src/database/read_transaction_cache.rs

@@ -53,14 +53,6 @@ impl<T: KeyValueDatabase + 'static> KeyValueDatabase for ReadTransactionCache<T>
     where
         T: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        // Safety: When T compiles fine and lower_read_transaction is implemented correctly this is
-        // safe to do.
-        unsafe { transmute::<&'r Self::ReadTransaction<'l>, &'r Self::ReadTransaction<'i>>(tx) }
-    }
-
     fn is_empty(&self) -> bool {
         self.database.is_empty()
     }

turbopack/crates/turbo-tasks-backend/src/database/startup_cache.rs

@@ -105,12 +105,6 @@ impl<T: KeyValueDatabase> KeyValueDatabase for StartupCacheLayer<T> {
     where
         Self: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        T::lower_read_transaction(tx)
-    }
-
     fn is_empty(&self) -> bool {
         self.database.is_empty()
     }

turbopack/crates/turbo-tasks-backend/src/database/turbo.rs

@@ -50,12 +50,6 @@ impl KeyValueDatabase for TurboKeyValueDatabase {
     where
         Self: 'l;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        tx
-    }
-
     fn is_empty(&self) -> bool {
         self.db.is_empty()
     }

turbopack/crates/turbo-tasks-backend/src/kv_backing_storage.rs

@@ -262,12 +262,6 @@ impl<T: KeyValueDatabase + Send + Sync + 'static> BackingStorageSealed
 {
     type ReadTransaction<'l> = T::ReadTransaction<'l>;
 
-    fn lower_read_transaction<'l: 'i + 'r, 'i: 'r, 'r>(
-        tx: &'r Self::ReadTransaction<'l>,
-    ) -> &'r Self::ReadTransaction<'i> {
-        T::lower_read_transaction(tx)
-    }
-
     fn next_free_task_id(&self) -> Result<TaskId> {
         Ok(TaskId::try_from(
             self.inner