1 files changed, 57 insertions, 0 deletions
diff --git a/src/rocksdb/table/scoped_arena_iterator.h b/src/rocksdb/table/scoped_arena_iterator.h
new file mode 100644
index 000000000..2b8824d95
--- /dev/null
+++ b/src/rocksdb/table/scoped_arena_iterator.h
@@ -0,0 +1,57 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+#pragma once
+
+#include "port/port.h"
+#include "table/internal_iterator.h"
+
+namespace ROCKSDB_NAMESPACE {
+class ScopedArenaIterator {
+  void reset(InternalIterator* iter) noexcept {
+    if (iter_ != nullptr) {
+      iter_->~InternalIterator();
+    }
+    iter_ = iter;
+  }
+
+ public:
+  explicit ScopedArenaIterator(InternalIterator* iter = nullptr)
+      : iter_(iter) {}
+
+  ScopedArenaIterator(const ScopedArenaIterator&) = delete;
+  ScopedArenaIterator& operator=(const ScopedArenaIterator&) = delete;
+
+  ScopedArenaIterator(ScopedArenaIterator&& o) noexcept {
+    iter_ = o.iter_;
+    o.iter_ = nullptr;
+  }
+
+  ScopedArenaIterator& operator=(ScopedArenaIterator&& o) noexcept {
+    reset(o.iter_);
+    o.iter_ = nullptr;
+    return *this;
+  }
+
+  InternalIterator* operator->() { return iter_; }
+  InternalIterator* get() { return iter_; }
+
+  void set(InternalIterator* iter) { reset(iter); }
+
+  InternalIterator* release() {
+    assert(iter_ != nullptr);
+    auto* res = iter_;
+    iter_ = nullptr;
+    return res;
+  }
+
+  ~ScopedArenaIterator() { reset(nullptr); }
+
+ private:
+  InternalIterator* iter_;
+};
+}  // namespace ROCKSDB_NAMESPACE